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Sample records for subacromial impingement structural

  1. Subacromial impingement syndrome

    NARCIS (Netherlands)

    Umer, M.; Qadir, I.; Azam, M.

    2012-01-01

    Subacromial impingement syndrome (SAIS) represents a spectrum of pathology ranging from subacromial bursitis to rotator cuff tendinopathy and full-thickness rotator cuff tears. The relationship between subacromial impingement and rotator cuff disease in the etiology of rotator cuff injury is a

  2. Subacromial impingement syndrome

    Directory of Open Access Journals (Sweden)

    Masood Umer

    2012-05-01

    Full Text Available Subacromial impingement syndrome (SAIS represents a spectrum of pathology ranging from subacromial bursitis to rotator cuff tendinopathy and full-thickness rotator cuff tears. The relationship between subacromial impingement and rotator cuff disease in the etiology of rotator cuff injury is a matter of debate. However the etiology is multi-factorial, and has been attributed to both extrinsic and intrinsic mechanisms. Management includes physical therapy, injections, and, for some patients, surgery. No high-quality RCTs are available so far to provide possible evidence for differences in outcome of different treatment strategies. There remains a need for high-quality clinical research on the diagnosis and treatment of SAIS.

  3. Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome

    DEFF Research Database (Denmark)

    Storgaard, Filip Holst; Pedersen, Christina Gravgaard; Jensen, Majbritt Lykke

    Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome.......Physiotherapy improves patient reported shoulder function and health status in patients with subacromial impingement syndrome....

  4. Current UK practices in the management of subacromial impingement

    Science.gov (United States)

    Drury, Colin; Tait, Gavin R

    2015-01-01

    Background Controversy presently exists surrounding the management of patients with subacromial impingement. This study aims to highlight current UK practices in the management of these patients. Methods BESS members were invited to complete a questionnaire and responses were received from 157 consultant shoulder surgeons. Results Physiotherapy is an integral part of management for 93% of surgeons with a minimum period of 12 weeks being most popular prior to consideration of arthroscopic subacromial decompression. Subacromial steroid injection is used by 95% and 86% repeat this if the patient has failed to respond to a previous injection by the general practioner. From initial presentation, 77% felt there should be at least 3 months of conservative management before proceeding to surgery. Good but transient response to subacromial injection was considered the best predictor of good surgical outcome by 77%. The coracoacromial ligament is fully released by 78%, although there was greater variation in how aggressive surgeons were with acromioplasty. Most (59%) do not include the nontender acromioclavicular joint to any extent in routine acromioplasty. Hospital physiotherapy protocols are used by 63% for postoperative rehabilitation. Conclusions Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steriod injections. PMID:27582972

  5. Current UK practices in the management of subacromial impingement.

    Science.gov (United States)

    Bryceland, James K; Drury, Colin; Tait, Gavin R

    2015-07-01

    Controversy presently exists surrounding the management of patients with subacromial impingement. This study aims to highlight current UK practices in the management of these patients. BESS members were invited to complete a questionnaire and responses were received from 157 consultant shoulder surgeons. Physiotherapy is an integral part of management for 93% of surgeons with a minimum period of 12 weeks being most popular prior to consideration of arthroscopic subacromial decompression. Subacromial steroid injection is used by 95% and 86% repeat this if the patient has failed to respond to a previous injection by the general practioner. From initial presentation, 77% felt there should be at least 3 months of conservative management before proceeding to surgery. Good but transient response to subacromial injection was considered the best predictor of good surgical outcome by 77%. The coracoacromial ligament is fully released by 78%, although there was greater variation in how aggressive surgeons were with acromioplasty. Most (59%) do not include the nontender acromioclavicular joint to any extent in routine acromioplasty. Hospital physiotherapy protocols are used by 63% for postoperative rehabilitation. Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steriod injections.

  6. Subacromial Impingement Syndrome Caused by a Voluminous Subdeltoid Lipoma

    Directory of Open Access Journals (Sweden)

    Jean-Christophe Murray

    2014-01-01

    Full Text Available Subacromial impingement syndrome is a clinical diagnosis encompassing a spectrum of possible etiologies, including subacromial bursitis, rotator cuff tendinopathy, and partial- to full-thickness rotator cuff tears. This report presents an unusual case of subdeltoid lipoma causing extrinsic compression and subacromial impingement syndrome. The patient, a 60-year-old man, presented to our institution with a few years' history of nontraumatic, posteriorly localized throbbing pain in his right shoulder. Despite a well-followed 6-months physiotherapy program, the patient was still suffering from his right shoulder. The MRI scan revealed a well-circumscribed 6 cm × 2 cm × 5 cm homogenous lesion compatible with a subdeltoid intermuscular lipoma. The mass was excised en bloc, and subsequent histopathologic examination confirmed a benign lipoma. At 6-months follow-up, the patient was asymptomatic with a complete return to his activities. Based on this case and a review of the literature, a subacromial lipoma has to be included in the differential diagnosis of a subacromial impingement syndrome refractory to nonoperative treatment. Complementary imaging modalities are required only after a failed conservative management to assess the exact etiology and successfully direct the surgical treatment.

  7. The Use of Physiotherapy among Patients with Subacromial Impingement Syndrome

    DEFF Research Database (Denmark)

    Christiansen, David Høyrup; Frost, Poul; Frich, Lars Henrik

    2016-01-01

    BACKGROUND: Physiotherapy with exercises is generally recommended in the treatment of patients with subacromial impingement syndrome (SIS). OBJECTIVE: We aimed to investigate the use of physiotherapy in patients with SIS in Danish hospital settings as part of initial non-surgical treatment...... and after SIS-related surgery and to evaluate to which extent sex, socio-demographic and clinical factors predict the use of physiotherapy. METHODS: Using national health registers, we identified 57,311 patients who had a first hospital contact with a diagnosis of ICD-10, groups M75.1-75.9, 1 July 2007...... to 30 June 2011. Records of physiotherapy were extracted within 52 weeks after first contact (or until surgery), and for surgically treated patients within 26 weeks after surgery. Predictors of the use of physiotherapy after first contact and after surgery were analysed as time-to-event. RESULTS: Within...

  8. Specific or general exercise strategy for subacromial impingement syndrome-does it matter?

    DEFF Research Database (Denmark)

    Shire, Alison R; Stæhr, Thor A B; Overby, Jesper B

    2017-01-01

    Background Exercise is frequently suggested as a treatment option for patients presenting with symptoms of subacromial impingement syndrome. Some would argue implementing a specific exercise strategy with special focus on correction of kinematic deficits would be superior to general exercise stra...

  9. The activity pattern of shoulder muscles in subjects with and without subacromial impingement

    DEFF Research Database (Denmark)

    Diederichsen, Louise Pyndt; Nørregaard, Jesper; Dyhre-Poulsen, Poul

    2009-01-01

    Altered shoulder muscle activity is frequently believed to be a pathogenetic factor of subacromial impingement (SI) and therapeutic interventions have been directed towards restoring normal motor patterns. Still, there is a lack of scientific evidence regarding the changes in muscle activity in p...... that the different motor patterns might be a pathogenetic factor of SI, perhaps due to inappropriate neuromuscular strategies affecting both shoulders....

  10. Subacromial impingement in patients with whiplash injury to the cervical spine

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    Giddins Grey E

    2008-06-01

    Full Text Available Abstract Background Impingement syndrome and shoulder pain have been reported to occur in a proportion of patients following whiplash injuries to the neck. In this study we aim to examine these findings to establish the association between subacromial impingement and whiplash injuries to the cervical spine. Methods and results We examined 220 patients who had presented to the senior author for a medico-legal report following a whiplash injury to the neck. All patients were assessed for clinical evidence of subacromial impingement. 56/220 patients (26% had developed shoulder pain following the injury; of these, 11/220 (5% had clinical evidence of impingement syndrome. Only 3/11 patients (27% had the diagnosis made prior to evaluation for their medico-legal report. In the majority, other clinicians had overlooked the diagnosis. The seatbelt shoulder was involved in 83% of cases (p Conclusion After a neck injury a significant proportion of patients present with shoulder pain, some of whom have treatable shoulder pathology such as impingement syndrome. The diagnosis is, however, frequently overlooked and shoulder pain is attributed to pain radiating from the neck resulting in long delays before treatment. It is important that this is appreciated and patients are specifically examined for signs of subacromial impingement after whiplash injuries to the neck. Direct seatbelt trauma to the shoulder is one possible explanation for its aetiology.

  11. Secondary Subacromial Impingement after Valgus Closing-Wedge Osteotomy for Proximal Humerus Varus

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    Hirotaka Sano

    2015-01-01

    Full Text Available A 31-year-old construction worker had been suffering from both the motion pain and the restriction of elevation in his right shoulder due to severe varus deformity of humeral neck, which occurred after proximal humeral fracture. The angle for shoulder flexion and abduction was restricted to 50 and 80 degrees, respectively. Valgus closing-wedge osteotomy followed by the internal fixation using a locking plate was carried out at 12 months after injury. Postoperatively, the head-shaft angle of the humerus improved from 65 to 138 degrees. Active flexion and abduction angles improved from 80 to 135 degrees and from 50 to 135 degrees, respectively. However, the patient complained from a sharp pain with a clicking sound during shoulder abduction even after removal of the locking plate. Since subacromial steroid injection temporarily relieved his shoulder pain, we assumed that the secondary subacromial impingement was provoked after osteotomy. Thus, arthroscopic subacromial decompression was carried out at 27 months after the initial operation, which finally relieved his symptoms. In the valgus closing-wedge osteotomy, surgeons should pay attention to the condition of subacromial space to avoid causing the secondary subacromial impingement.

  12. Preoperative conventional magnetic resonance images versus magnetic resonance arthrography of subacromial impingement syndrome

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    Ahn, Sang Hyuk; Park, Jung Hwan; Moon, Tae Yong; Lee, In Sook; Lee, Seung Jun

    2012-01-01

    To evaluate the usefulness of conventional magnetic resonance images (MRI) for arthroscopic surgery in subacromial impingement syndrome of the shoulder, as an alternative to MR arthrography with additional T2 fat saturation images (MRA). The preoperative MRI of 77 patients (45 females, 32 males) (52 right, 25 left) and MRA of 34 patients (14 females, 20 males) (24 right, 10 left) with subsequent arthroscopic confirmation of subacromial impingement syndrome were reviewed retrospectively. The lesions requiring arthroscopic surgery were 95 subacromial spurs, 101 subacromial bursitis, and 51 full-thickness and 44 partial thickness tears of the supraspinatus among 111 cases for both studies. A two by two table was constructed in order to calculate the sensitivity and specificity of both studies against arthroscopic outcomes. Also we analyzed the false positive and false negative cases of the full-thickness tears individually. The detection rates of subacromial spur and bursitis and full and partial thickness tears of the supraspinatus were 91%, 94%, 77%, and 65% in MRI and 93%, 100%, 83%, and 77% in MRA respectively. Their specificities were 33%, 33%, 90%, and 76% in MRI and 50%, 75%, 100%, and 71% in MRA respectively. Eleven false negative cases in regards to MRI resulted in Ellman's grade 3 partial thickness tear (72.7%), mild bursitis (63.6%), greater tuberosity erosion (45.5%), and negative fluid signal of the glenohumeral joint (81.8%). Three false positive cases on the MRI were induced from errors with lower window depth and width on the imagings. Two false negative cases on MRA were induced from the adhesion between Ellman's grade 3 rim rent tear and the glenohumeral joint cavity. Conventional MR images could be used to decide the arthroscopic surgery in subacromial impingement syndrome, as an alternative to MR arthrography with additional T2 fat saturation images

  13. Preoperative conventional magnetic resonance images versus magnetic resonance arthrography of subacromial impingement syndrome

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    Ahn, Sang Hyuk; Park, Jung Hwan; Moon, Tae Yong [Pusan National Univ. Yangsan Hospital, Yangsan (Korea, Republic of); Lee, In Sook; Lee, Seung Jun [Pusan National Univ. Hospital, Busan (Korea, Republic of)

    2012-09-15

    To evaluate the usefulness of conventional magnetic resonance images (MRI) for arthroscopic surgery in subacromial impingement syndrome of the shoulder, as an alternative to MR arthrography with additional T2 fat saturation images (MRA). The preoperative MRI of 77 patients (45 females, 32 males) (52 right, 25 left) and MRA of 34 patients (14 females, 20 males) (24 right, 10 left) with subsequent arthroscopic confirmation of subacromial impingement syndrome were reviewed retrospectively. The lesions requiring arthroscopic surgery were 95 subacromial spurs, 101 subacromial bursitis, and 51 full-thickness and 44 partial thickness tears of the supraspinatus among 111 cases for both studies. A two by two table was constructed in order to calculate the sensitivity and specificity of both studies against arthroscopic outcomes. Also we analyzed the false positive and false negative cases of the full-thickness tears individually. The detection rates of subacromial spur and bursitis and full and partial thickness tears of the supraspinatus were 91%, 94%, 77%, and 65% in MRI and 93%, 100%, 83%, and 77% in MRA respectively. Their specificities were 33%, 33%, 90%, and 76% in MRI and 50%, 75%, 100%, and 71% in MRA respectively. Eleven false negative cases in regards to MRI resulted in Ellman's grade 3 partial thickness tear (72.7%), mild bursitis (63.6%), greater tuberosity erosion (45.5%), and negative fluid signal of the glenohumeral joint (81.8%). Three false positive cases on the MRI were induced from errors with lower window depth and width on the imagings. Two false negative cases on MRA were induced from the adhesion between Ellman's grade 3 rim rent tear and the glenohumeral joint cavity. Conventional MR images could be used to decide the arthroscopic surgery in subacromial impingement syndrome, as an alternative to MR arthrography with additional T2 fat saturation images.

  14. Force steadiness, muscle activity, and maximal muscle strength in subjects with subacromial impingement syndrome

    DEFF Research Database (Denmark)

    Bandholm, Thomas; Rasmussen, Lars; Aagaard, Per

    2006-01-01

    physically active in spite of shoulder pain and nine healthy matched controls were examined to determine isometric and isokinetic submaximal shoulder-abduction force steadiness at target forces corresponding to 20%, 27.5%, and 35% of the maximal shoulder abductor torque, and maximal shoulder muscle strength......We investigated the effects of the subacromial impingement syndrome (SIS) on shoulder sensory-motor control and maximal shoulder muscle strength. It was hypothesized that both would be impaired due to chronic shoulder pain associated with the syndrome. Nine subjects with unilateral SIS who remained...

  15. Effectiveness of Kinesiotaping and Subacromial Corticosteroid Injection in Shoulder Impingement Syndrome.

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    Şahin Onat, Şule; Biçer, Seda; Şahin, Zehra; Küçükali Türkyilmaz, Ayşegül; Kara, Murat; Özbudak Demir, Sibel

    2016-08-01

    The aim of this study was to investigate whether kinesiotaping or subacromial corticosteroid injection provides additional benefit when used with nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with shoulder impingement syndrome. Patients with shoulder impingement syndrome were divided into 3 groups as follows: NSAID group (n = 33), kinesiotaping group (kinesiotaping + NSAID) (n = 33), and injection group (subacromial corticosteroid injection + NSAID) (n = 33). Outcome measures including visual analog scale, shoulder ranges of motion, Shoulder Disability Questionnaire, and University of California-Los Angeles (UCLA) scale were evaluated before and after the treatment (fourth week). A total of 99 patients (21 male and 78 female patients) were enrolled in this study. Demographic and baseline clinical characteristics of the groups (except for body mass index and visual analog scale at night, both P = 0.05) were similar between the groups (all P > 0.05). Clinical parameters were found to have improved in the 3 groups (all P kinesiotaping and injection groups showed similar improvements (all P > 0.05), each group had better outcome than did the NSAID group as regards pain (activity visual analog scale), ranges of motion, and Shoulder Disability Questionnaire and UCLA scale scores (all P kinesiotaping or subacromial corticosteroid injection to NSAID treatment seems to have better/similar effectiveness in patients with shoulder impingement syndrome. Therefore, kinesiotaping might serve as an alternative treatment in case (injection of) corticosteroids are contraindicated. Complete the self-assessment activity and evaluation online at http://www.physiatry.org/JournalCME CME OBJECTIVES:: Upon completion of this article, the reader should be able to: (1) Delineate appropriate treatment options for shoulder impingement syndrome; (2) Identify treatment benefits of kinesiotaping and corticosteroid injections in shoulder impingement syndrome; and (3) Incorporate

  16. Intra-rater and inter-rater reliability of the standardized ultrasound protocol for assessing subacromial structures

    DEFF Research Database (Denmark)

    Hougs Kjær, Birgitte; Ellegaard, Karen; Wieland, Ina

    2017-01-01

    BACKGROUND: US-examinations related to shoulder impingement (SI) often vary due to methodological differences, examiner positions, transducers, and recording parameters. Reliable US protocols for examination of different structures related to shoulder impingement are therefore needed. OBJECTIVES...... of the supraspinatus tendon (SUPRA) and subacromial subdeltoid (SASD) bursa in two imaging positions, and the acromial humeral distance (AHD) in one position. Additionally, agreement on dynamic impingement (DI) examination was performed. The intra- and inter-rater reliability was carried out on the same day...

  17. Effectiveness of Standardized Physiotherapy Exercises for Patients With Difficulty Returning to Usual Activities After Decompression Surgery for Subacromial Impingement Syndrome

    DEFF Research Database (Denmark)

    Christiansen, David Høyrup; Frost, Poul; Falla, Deborah

    2016-01-01

    BACKGROUND: Little is known about the effectiveness of exercise programs after decompression surgery for subacromial impingement syndrome. For patients with difficulty returning to usual activities, special efforts may be needed to improve shoulder function. OBJECTIVE: The purpose of this study w...

  18. Quantitative and qualitative analyses of subacromial impingement by kinematic open MRI.

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    Tasaki, Atsushi; Nimura, Akimoto; Nozaki, Taiki; Yamakawa, Akira; Niitsu, Mamoru; Morita, Wataru; Hoshikawa, Yoshimitsu; Akita, Keiichi

    2015-05-01

    Quantitative and qualitative kinematic analyses of subacromial impingement by 1.2T open MRI were performed to determine the location of impingement and the involvement of the acromioclavicular joint. In 20 healthy shoulders, 10 sequential images in the scapular plane were taken in a 10-s pause at equal intervals from 30° to maximum abduction in neutral and internal rotation. The distances between the rotator cuff (RC) and the acromion and the acromioclavicular joint were measured. To comprehend the positional relationships, cadaveric specimens were also observed. Although asymptomatic, the RC came into contact with the acromion and the acromioclavicular joint in six and five cases, respectively. The superior RC acted as a depressor for the humeral head against the acromion as the shoulder elevated. The mean elevation angle and distance at the closest position between the RC and the acromion in neutral rotation were 93.5° and 1.6 mm, respectively, while those between the RC and the acromioclavicular joint were 86.7° and 2.0 mm. When comparing this distance and angle, there was no significant difference between the RC to the acromion and to the acromioclavicular joint. The minimum distance between the RC and the acromion was significantly shorter than that between the greater tuberosity and the acromion. The location of RC closest to the acromion and the acromioclavicular joint differed significantly. Although asymptomatic, contact was found between the RC and the acromion and the acromioclavicular joint. The important role of the RC to prevent impingement was observed, and hence, dysfunction of the RC could lead to impingement that could result in a RC lesion. The RC lesions may differ when they are caused by impingement from either the acromion or the acromioclavicular joint.

  19. Risk of surgery for subacromial impingement syndrome in relation to neck-shoulder complaints and occupational biomechanical exposures

    DEFF Research Database (Denmark)

    Svendsen, Susanne Wulff; Dalbøge, Annett; Andersen, JH

    2013-01-01

    OBJECTIVES: The aim of this longitudinal study was to evaluate the risk of surgery for subacromial impingement syndrome (SIS) in relation to neck-shoulder complaints and occupational biomechanical shoulder exposures. METHODS: The study was based on the Musculoskeletal Research Database at the Dan......OBJECTIVES: The aim of this longitudinal study was to evaluate the risk of surgery for subacromial impingement syndrome (SIS) in relation to neck-shoulder complaints and occupational biomechanical shoulder exposures. METHODS: The study was based on the Musculoskeletal Research Database....... Using no neck-shoulder complaints and low shoulder load at baseline as a reference, no neck-shoulder complaints and high shoulder load showed an adjusted hazard ratio (HR adj) of 2.55 [95% confidence interval (95% CI) 1.59-4.09], while neck-shoulder complaints in combination with high shoulder load...

  20. Cumulative occupational shoulder exposures and surgery for subacromial impingement syndrome: a nationwide Danish cohort study.

    Science.gov (United States)

    Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

    2014-11-01

    The primary aim was to examine exposure-response relationships between cumulative occupational shoulder exposures and surgery for subacromial impingement syndrome (SIS), and to compare sex-specific exposure-response relationships. The secondary aim was to examine the time window of relevant exposures. We conducted a nationwide register study of all persons born in Denmark (1933-1977), who had at least 5 years of full-time employment. In the follow-up period (2003-2008), we identified first-time events of surgery for SIS. Cumulative exposure estimates for a 10-year exposure time window with a 1-year lag time were obtained by linking occupational codes with a job exposure matrix. The exposure estimates were expressed as, for example, arm-elevation-years in accordance with the pack-year concept of tobacco consumption. We used a multivariable logistic regression technique equivalent to discrete survival analysis. The adjusted OR (ORadj) increased to a maximum of 2.1 for arm-elevation-years, repetition-years and force-years, and to 1.5 for hand-arm-vibration-years. Sex-specific exposure-response relationships were similar for men and women, when assessed using a relative risk scale. The ORadj increased gradually with the number of years contributing to the cumulative exposure estimates. The excess fraction was 24%. Cumulative occupational shoulder exposures carried an increase in risk of surgery for SIS with similar exposure-response curves for men and women. The risk of surgery for SIS increased gradually, when the period of exposure assessment was extended. In the general working population, a substantial fraction of all first-time operations for SIS could be related to occupational exposures. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  1. Inter- and intrarater reliability of goniometry and hand held dynamometry for patients with subacromial impingement syndrome.

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    Fieseler, Georg; Laudner, Kevin G; Irlenbusch, Lars; Meyer, Henrike; Schulze, Stephan; Delank, Karl-Stefan; Hermassi, Souhail; Bartels, Thomas; Schwesig, René

    2017-12-01

    The purpose of this study was to examine the intra- and interrater reliability of measuring shoulder range of motion (ROM) and strength among patients diagnosed with subacromial impingement syndrome (SAIS). Twenty-five patients (14 female patients; mean age, 60.4± 7.84 years) diagnosed with SAIS were assessed to determine the intrarater reliability for glenohumeral ROM. Twenty-five patients (16 female patients; mean age, 60.4± 7.80 years) and 76 asymptomatic volunteers (52 female volunteers; mean age, 29.4± 14.1 years) were assessed for interrater reliability. Dependent variables were active shoulder ROM and isometric strength. Intrarater reliability was fair-to-excellent for the SAIS patients (intraclass correlation coefficient [ICC], 0.52-0.97; standard error of measurement [SEM], 4.4°-9.9° N; coefficient of variation [CV], 7.1%-44.9%). Based on the ICC, 11 of 12 parameters (92%) displayed an excellent reliability (ICC> 0.75). The interrater reliability showed fair-to-excellent results (SAIS patients: ICC, 0.13-0.98; SEM, 2.3°-8.8°; CV, 3.6%-37.0%; controls: ICC, 0.11-0.96; SEM, 3.0°-35.4°; CV, 5.6%-26.4%). In accordance with the intrarater reliability, glenohumeral adduction ROM was the only parameter with an ICC below 0.75 for both samples. Painful shoulder ROM in the SAIS patients showed no influence on the quality of reliability for measurement. Therefore, these protocols should be considered reliable assessment techniques in the prevention, diagnosis, and treatment of painful shoulder conditions such as SAIS.

  2. Exercises versus arthroscopic decompression in patients with subacromial impingement: a randomised, controlled study in 90 cases with a one year follow up

    DEFF Research Database (Denmark)

    Haahr, J. P.; Ostergaard, S.; Dalsgaard, J.

    2005-01-01

    , the difference being non-significant. No group differences in mean pain and dysfunction score improvement were found. CONCLUSIONS: Surgical treatment of rotator cuff syndrome with subacromial impingement was not superior to physiotherapy with training. Further studies are needed to qualify treatment choice...

  3. Ultrasound measurement of rotator cuff thickness and acromio-humeral distance in the diagnosis of subacromial impingement syndrome of the shoulder.

    Science.gov (United States)

    Cholewinski, Jerzy J; Kusz, Damian J; Wojciechowski, Piotr; Cielinski, Lukasz S; Zoladz, Miroslaw P

    2008-04-01

    The usefulness of ultrasound measurements in the diagnosis of the subacromial impingement syndrome of the shoulder was evaluated. Fifty-seven patients with unilateral symptoms of the impingement syndrome underwent ultrasound examination of both shoulder joints, which included assessment of rotator cuff integrity, measurement of rotator cuff thickness and the distance between the infero-lateral edge of acromion and the apex of the greater tuberosity of humerus (AGT distance) in the standard ultrasonographic positions. As a control group, 36 volunteers (72 shoulders) with no history of shoulder pain were examined sonographically. Ultrasonographic assessment of humeral head elevation, measured as the AGT distance, proved to be useful in establishing the diagnosis of the subacromial impingement syndrome of the shoulder. A difference in rotator cuff thickness of more than 1.1 mm and a difference in the AGT distance of more than 2.1 mm between both shoulder joints may reflect dysfunction of rotator cuff muscles.

  4. Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows

    DEFF Research Database (Denmark)

    Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid

    2018-01-01

    OBJECTIVES: We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate...... if exposure to hand-arm vibration (HAV) is an independent risk factor. METHODS: We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register...... of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. RESULTS: We found indications of safe exposure intensities for repetition (median angular...

  5. The Effect of Platelet-Rich Plasma (PRP on Improvement in Pain and Symptoms of Shoulder Subacromial Impingement Syndrome

    Directory of Open Access Journals (Sweden)

    Parisa Nejati

    2015-08-01

    Full Text Available Abstract Background: Subacromial impingement is one of the most common complaints of shoulder. Treatments include avoiding of painful activities, oral anti-pain drugs, physical therapy modalities, corticosteroid injection and exercise therapy. Some studies have shown that platelet- rich plasma(PRP is effective on tendinitis and tearing of tendons, ligaments and muscles, but evidence that has proved PRP as a conservative treatment in shoulder pathologies is very limited. This study aims to investigate the effect of PRP injection on relieving pain and improving daily function of patients with shoulder impingement syndrome. Materials and Methods: In this clinical trial study, patients older than 40 with pain more than three months were included. If they had three of four positive diagnostic clinical tests of shoulder impingement that were confirmed by shoulder MRI, could be injected PRP twice. The time between injections was 1 month. Pain was measured by visual analog scale (VAS and function was measured by two questionnaires named disabilities of the arm, shoulder and hand (DASH and western Ontario rotator cuff index (WORC. Range of motion (ROM of shoulder was measured in five directions by goniometry . All of these parameters were evaluated before intervention and in 1, 3, 6 months later. Results: with due attention to a six-month folloe-up, PRR injection was effective in pain reduction and improvement of patient's function (p<0.05. Shoulder Rom increased in all directions except external rotation and the power of shoulder muscles was evidently improved statistically in flexion, abduction and internal toration. Conclusion: PRP injection could effectively reduce pain and improve daily activities in patients with shoulder impingement syndrome.

  6. The clinical and sonographic effects of kinesiotaping and exercise in comparison with manual therapy and exercise for patients with subacromial impingement syndrome: a preliminary trial.

    Science.gov (United States)

    Kaya, Derya Ozer; Baltaci, Gul; Toprak, Ugur; Atay, Ahmet Ozgur

    2014-01-01

    The purpose of this study was to compare the effects of manual therapy with exercise to kinesiotaping with exercise for patients with subacromial impingement syndrome. Randomized clinical before and after trial was used. Fifty-four patients diagnosed as having subacromial impingement syndrome who were referred for outpatient treatment were included. Eligible patients (between 30 and 60 years old, with unilateral shoulder pain) were randomly allocated to 2 study groups: kinesiotaping with exercise (n = 28) or manual therapy with exercise (n = 26). In addition, patients were advised to use cold packs 5 times per day to control for pain. Visual analog scale for pain, Disability of Arm and Shoulder Questionnaire for function, and diagnostic ultrasound assessment for supraspinatus tendon thickness were used as main outcome measures. Assessments were applied at the baseline and after completing 6 weeks of related interventions. At the baseline, there was no difference between the 2 group characteristics (P > .05). There were significant differences in both groups before and after treatment in terms of pain decrease and improvement of Disability of Arm and Shoulder Questionnaire scores (P .05). The only difference between the groups was at night pain, resulting in favor of the kinesiotaping with exercise group (P kinesiotaping with exercise and manual therapy with exercise. Both treatments may have similar results in reducing pain and disability in subacromial impingement in 6 weeks. Copyright © 2014 National University of Health Sciences. Published by Elsevier Inc. All rights reserved.

  7. The impact of subacromial impingement syndrome on muscle activity patterns of the shoulder complex: a systematic review of electromyographic studies

    Directory of Open Access Journals (Sweden)

    Smith Toby O

    2010-03-01

    Full Text Available Abstract Background Subacromial impingement syndrome (SIS is a commonly reported cause of shoulder pain. The purpose of this study was to systematically review the literature to examine whether a difference in electromyographic (EMG activity of the shoulder complex exists between people with SIS and healthy controls. Methods Medline, CINAHL, AMED, EMBASE, and grey literature databases were searched from their inception to November 2008. Inclusion, data extraction and trial quality were assessed in duplicate. Results Nine studies documented in eleven papers, eight comparing EMG intensity and three comparing EMG onset timing, representing 141 people with SIS and 138 controls were included. Between one and five studies investigated each muscle totalling between 20 and 182 participants. The two highest quality studies of five report a significant increase in EMG intensity in upper trapezius during scaption in subjects with SIS. There was evidence from 2 studies of a delayed activation of lower trapezius in patients with SIS. There was otherwise no evidence of a consistent difference in EMG activity between the shoulders of subjects with painful SIS and healthy controls. Conclusions A difference may exist in EMG activity within some muscles, in particular upper and lower trapezius, between people with SIS and healthy controls. These muscles may be targets for clinical interventions aiding rehabilitation for people with SIS. These differences should be investigated in a larger, high quality survey and the effects of therapeutically targeting these muscles in a randomised controlled trial.

  8. Does taping in addition to physiotherapy improve the outcomes in subacromial impingement syndrome? A systematic review.

    Science.gov (United States)

    Saracoglu, Ismail; Emuk, Yusuf; Taspinar, Ferruh

    2018-04-01

    Taping is used with or without other interventions for many purposes, especially to manage pain and improve functional activity in patients with shoulder pain. The aim of this review was to determine whether any taping technique in addition to physiotherapy care is more effective than physiotherapy care alone in patients with shoulder impingement syndrome. A systematic search of Cochrane Database of Systematic Review, MEDLINE (EBSCO), Physiotherapy Evidence Database (PEDro), CINAHL (EBSCO), PUBMED, AMED, EMBASE (OVID), The Kinesio Kinesio® Taping Method, Kinesio® Tex Tape UK and International websites ( www.kinesiotaping.co.uk ; www.kinesiotaping.com ) was conducted to June 2015. The outcome measures were pain, disability, range of motion and muscle strength. As data were not suitable for meta-analysis, narrative synthesis were applied. Three randomized controlled trials and one controlled trial (135 patients) were included. The results were conflicting and weak on the effectiveness of taping as an adjunct therapy for improvement of pain, disability, range of motion and muscle strength. Clinical taping in addition to physiotherapy interventions (e.g. exercise, electrotherapy, and manual therapy) might be an optional modality for managing patients with shoulder impingement syndrome, especially for the initial stage of the treatment; however, we need further robust, placebo controlled and consistent studies to prove whether it is more effective than physiotherapy interventions without taping.

  9. Surgery for subacromial impingement syndrome in relation to intensities of occupational mechanical exposures across 10-year exposure time windows.

    Science.gov (United States)

    Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

    2018-03-01

    We aimed to identify intensities of occupational mechanical exposures (force, arm elevation and repetition) that do not entail an increased risk of surgery for subacromial impingement syndrome (SIS) even after prolonged durations of exposure. Additionally, we wanted to evaluate if exposure to hand-arm vibration (HAV) is an independent risk factor. We used data from a register-based cohort study of the entire Danish working population (n=2 374 403). During follow-up (2003-2008), 14 118 first-time events of surgery for SIS occurred. For each person, we linked register-based occupational codes (1993-2007) to a general population job exposure matrix to obtain year-by-year exposure intensities on measurement scales for force, upper arm elevation >90° and repetition and expert rated intensities of exposure to HAV. For 10-year exposure time windows, we calculated the duration of exposure at specific intensities above minimal (low, medium and high). We used a logistic regression technique equivalent to discrete survival analysis adjusting for cumulative effects of other mechanical exposures. We found indications of safe exposure intensities for repetition (median angular velocity 90° >2 min/day implied an increased risk reaching ORs of 1.7 and 1.5 after 10 years at low intensities. No associations were found for HAV. We found indications of safe exposure intensities for repetition. Any intensities of force and upper arm elevation >90° above minimal implied an increased risk across 10-year exposure time windows. No independent associations were found for HAV. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  10. The Use of Physiotherapy among Patients with Subacromial Impingement Syndrome: Impact of Sex, Socio-Demographic and Clinical Factors

    Science.gov (United States)

    Christiansen, David Høyrup; Frost, Poul; Frich, Lars Henrik; Falla, Deborah; Svendsen, Susanne Wulff

    2016-01-01

    Background Physiotherapy with exercises is generally recommended in the treatment of patients with subacromial impingement syndrome (SIS). Objective We aimed to investigate the use of physiotherapy in patients with SIS in Danish hospital settings as part of initial non-surgical treatment and after SIS-related surgery and to evaluate to which extent sex, socio-demographic and clinical factors predict the use of physiotherapy. Methods Using national health registers, we identified 57,311 patients who had a first hospital contact with a diagnosis of ICD-10, groups M75.1–75.9, 1 July 2007 to 30 June 2011. Records of physiotherapy were extracted within 52 weeks after first contact (or until surgery), and for surgically treated patients within 26 weeks after surgery. Predictors of the use of physiotherapy after first contact and after surgery were analysed as time-to-event. Results Within 52 weeks after first contact, 43% of the patients had physiotherapy and 30% underwent surgery. Within 26 weeks after surgery, 80% had a record of physiotherapy. After first contact and after surgery, exercise was part of physiotherapy in 65% and 84% of the patients, respectively. A public hospital contact, physiotherapy before hospital contact, administrative region, female sex, a diagnosis of other or unspecified disorders (M75.8-M75.9), and surgical procedure predicted higher use of physiotherapy. Low education level predicted slightly lower use of physiotherapy after first contact, but not after surgery. Conclusion In patients with SIS in Danish hospital settings, physiotherapy was more often used after surgery than as part of initial non-surgical treatment. The use of physiotherapy was less common among men than women, whereas unequal use of physiotherapy in relation to education level was not noticeable. The use of physiotherapy with exercises in initial non-surgical treatment was relatively limited. PMID:26954692

  11. Exercises may be as efficient as subacromial decompression in patients with subacromial stage II impingement: 4-8-years' follow-up in a prospective, randomized study

    DEFF Research Database (Denmark)

    Haahr, J. P.; Andersen, JH

    2006-01-01

    with graded physiotherapy and exercises or arthroscopic subacromial decompression. Outcomes were proportion of time per year with income transfers (indexed 0-1), including total transfers (marginalization), sick leave and disability pension obtained from the registry at the Ministry of Work. Self......-reported function, working capability, employment status and global improvement were obtained by questionnaire in September 2004. The main outcomes are given as differences in development from baseline. RESULTS: Seventy-nine (88%) responded to the questionnaire and registry data were obtained from 81. After 1 year...

  12. Effectiveness of individualized physiotherapy on pain and functioning compared to a standard exercise protocol in patients presenting with clinical signs of subacromial impingement syndrome. A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    de Bie Rob A

    2010-06-01

    Full Text Available Abstract Background Shoulder impingement syndrome is a common musculoskeletal complaint leading to significant reduction of health and disability. Physiotherapy is often the first choice of treatment although its effectiveness is still under debate. Systematic reviews in this field highlight the need for more high quality trials to investigate the effectiveness of physiotherapy interventions in patients with subacromial impingement syndrome. Methods/Design This randomized controlled trial will investigate the effectiveness of individualized physiotherapy in patients presenting with clinical signs and symptoms of subacromial impingement, involving 90 participants aged 18-75. Participants are recruited from outpatient physiotherapy clinics, general practitioners, and orthopaedic surgeons in Germany. Eligible participants will be randomly allocated to either individualized physiotherapy or to a standard exercise protocol using central randomization. The control group will perform the standard exercise protocol aiming to restore muscular deficits in strength, mobility, and coordination of the rotator cuff and the shoulder girdle muscles to unload the subacromial space during active movements. Participants of the intervention group will perform the standard exercise protocol as a home program, and will additionally be treated with individualized physiotherapy based on clinical examination results, and guided by a decision tree. After the intervention phase both groups will continue their home program for another 7 weeks. Outcome will be measured at 5 weeks and at 3 and 12 months after inclusion using the shoulder pain and disability index and patients' global impression of change, the generic patient-specific scale, the average weekly pain score, and patient satisfaction with treatment. Additionally, the fear avoidance beliefs questionnaire, the pain catastrophizing scale, and patients' expectancies of treatment effect are assessed. Participants

  13. Effectiveness of Standardized Physical Therapy Exercises for Patients With Difficulty Returning to Usual Activities After Decompression Surgery for Subacromial Impingement Syndrome: Randomized Controlled Trial.

    Science.gov (United States)

    Christiansen, David Høyrup; Frost, Poul; Falla, Deborah; Haahr, Jens Peder; Frich, Lars Henrik; Andrea, Linda Christie; Svendsen, Susanne Wulff

    2016-06-01

    Little is known about the effectiveness of exercise programs after decompression surgery for subacromial impingement syndrome. For patients with difficulty returning to usual activities, special efforts may be needed to improve shoulder function. The purpose of this study was to evaluate the effectiveness at 3 and 12 months of a standardized physical therapy exercise intervention compared with usual care in patients with difficulty returning to usual activities after subacromial decompression surgery. A multicenter randomized controlled trial was conducted. The study was conducted in 6 public departments of orthopedic surgery, 2 departments of occupational medicine, and 2 physical therapy training centers in Central Denmark Region. One hundred twenty-six patients reporting difficulty returning to usual activities at the postoperative clinical follow-up 8 to 12 weeks after subacromial decompression surgery participated. A standardized exercise program consisting of physical therapist-supervised individual training sessions and home training was used. The primary outcome measure was the Oxford Shoulder Score. Secondary outcome measures were the Constant Score and the Fear-Avoidance Beliefs Questionnaire. At 3 and 12 months, follow-up data were obtained for 92% and 83% of the patients, respectively. Intention-to-treat analyses suggested a between-group difference on the Oxford Shoulder Score favoring the exercise group at 3 months, with an adjusted mean difference of 2.0 (95% confidence interval=-0.5, 4.6), and at 12 months, with an adjusted mean difference of 5.8 (95% confidence interval=2.8, 8.9). Significantly larger improvements for the exercise group were observed for most secondary and supplementary outcome measures. The nature of the exercise intervention did not allow blinding of patients and care providers. The standardized physical therapy exercise intervention resulted in statistically significant and clinically relevant improvement in shoulder pain and

  14. Conservative treatment for patients with subacromial impingement: Changes in clinical core outcomes and their relation to specific rehabilitation parameters

    Directory of Open Access Journals (Sweden)

    Mikkel B. Clausen

    2018-02-01

    Full Text Available Background Impaired patient-reported shoulder function and pain, external-rotation strength, abduction strength, and abduction range-of-motion (ROM is reported in patients with subacromial impingement (SIS. However, it is unknown how much strength and ROM improves in real-life practice settings with current care. Furthermore, outcomes of treatment might depend on specific rehabilitation parameters, such as the time spent on exercises (exercise-time, number of physiotherapy sessions (physio-sessions and number of corticosteroid injections, respectively. However, this has not previously been investigated. The purpose of this study was to describe changes in shoulder strength, ROM, patient-reported function and pain, in real-life practice settings, and explore the association between changes in clinical core outcomes and specific rehabilitation parameters. Methods Patients diagnosed with SIS at initial assessment at an outpatient hospital clinic using predefined criteria’s, who had not undergone surgery after 6 months, were included in this prospective cohort study. After initial assessment (baseline, all patients underwent treatment as usual, with no interference from the investigators. The outcomes Shoulder Pain and Disability Index (SPADI:0–100, average pain (NRS:0–10, external rotation strength, abduction strength and abduction ROM, pain during each test (NRS:0–10, were collected at baseline and at six month follow-up. Amount of exercise-time, physio-sessions and steroid-injections was recorded at follow-up. Changes in outcomes were analyzed using Wilcoxon Signed-Rank test, and the corresponding effect sizes (ES were estimated. The associations between changes in outcomes and rehabilitation parameters were explored using multiple regression analyses. Results Sixty-three patients completed both baseline and follow-up testing. Significant improvements were seen in SPADI (19 points, ES:0.53, p  0.2. A higher number of physio-sessions was

  15. The effectiveness of injections of hyaluronic acid or corticosteroid in patients with subacromial impingement: a three-arm randomised controlled trial.

    Science.gov (United States)

    Penning, L I F; de Bie, R A; Walenkamp, G H I M

    2012-09-01

    A total of 159 patients (84 women and 75 men, mean age of 53 (20 to 87)) with subacromial impingement were randomised to treatment with subacromial injections using lidocaine with one of hyaluronic acid (51 patients), corticosteroid (53 patients) or placebo (55 patients). Patients were followed up for 26 weeks. The primary outcome was pain on a visual analogue score (VAS), and secondary outcomes included the Constant Murley score, shoulder pain score, functional mobility score, shoulder disability questionnaire and pain-specific disability score. The different outcome measures showed similar results. After three, six and 12 weeks corticosteroid injections were superior to hyaluronic acid injections and only at six weeks significantly better than placebo injections. The mean short-term reduction in pain on the VAS score at 12 weeks was 7% (SD 2.7; 97.5% confidence interval (CI) 0.207 to 1.55; p = 0.084) in the hyaluronic acid group, 28% (SD 2.8; 97.5% CI 1.86 to 3.65; p hyaluronic acid group, 72% (38 of 53) of those in the corticosteroid group and 69% (38 of 55) of those in the placebo group. We were not able to show a convincing benefit from hyaluronic acid injections compared with corticosteroid or placebo injections. Corticosteroid injections produced a significant reduction in pain in the short term (three to 12 weeks), but in the long term the placebo injection produced the best results.

  16. Muscle shortening maneuver and not topical anti-inflammatory therapy is effective in reducing the width of subacromial-subdeltoid bursa in shoulder impingement syndrome

    Science.gov (United States)

    Melchiorre, Daniela; Lippi, Paolo; Marchi, Alberto; Maresca, Marco; Bravi, Riccardo; Eros, Quarta; Lazzerini, Patrizia; Bagni, Maria Angela

    2018-04-01

    Aim of the study was to compare the efficacy of a muscle shortening maneuver (MSM) with the efficacy of a topical NSAID (flurbiprofen) in patients with subacromial impingement syndrome (SIS). The effects of these therapies were evaluated by sonographic exam (US). SIS was diagnosed by US in 78 patients with painful shoulder. Thirty patients (first group) were treated with topical flurbiprofen for 15 days. Forty-eight patients (second group) were treated with MSM, which was performed once. The shoulder was analyzed in all patients by US before and after treatment. Before treatment and 15 days after treatment, pain by Visual Analogue Scale (VAS), range of motion (ROM) and Neer's Test were evaluated. Pain was decreased by both treatments. In only 8 patients of the first group, the encroachment of acromion into the rotator cuff was no more detectable by US after the treatment; ROM increased (> 45°) only in 11 patients (36%) and the width of subacromial-subdeltoid bursa (SSB) was not significantly reduced. At variance with the results obtained in the first group, in all patients of the second group the encroachment of acromion was no more detectable by US, ROM increased (> 45°) and the width of SSB was significantly reduced after the maneuver. Both topical flurbiprofen and MSM were helpful in pain control, but better results, with decrease of width of SSB assessed by US, were obtained by MSM.

  17. Cost-effectiveness of exercise therapy after corticosteroid injection for moderate to severe shoulder pain due to subacromial impingement syndrome: a trial-based analysis.

    Science.gov (United States)

    Jowett, Sue; Crawshaw, Dickon P; Helliwell, Philip S; Hensor, Elizabeth M A; Hay, Elaine M; Conaghan, Philip G

    2013-08-01

    To perform a cost-effectiveness analysis of subacromial corticosteroid injection combined with exercise compared with exercise alone in patients with moderate to severe shoulder pain from subacromial impingement syndrome. A within-trial cost-effectiveness analysis with 232 patients randomized to physiotherapy-led injection combined with exercise (n = 115) or exercise alone (n = 117). The analysis was from a health care perspective with 24-week follow-up. Resource use information was collected from all patients on interventions, medication, primary and secondary care contacts, private health care use and over-the-counter purchases. The measure of outcome was quality-adjusted life years (QALYs), calculated from EQ-5D responses at baseline and three further time points. An incremental cost-effectiveness analysis was conducted. Mean per patient NHS costs (£255 vs £297) and overall health care costs (£261 vs £318) were lower in the injection plus exercise arm, but this difference was not statistically significant. Total QALYs gained were very similar in the two trial arms (0.3514 vs 0.3494 QALYs), although slightly higher in the injection plus exercise arm, indicating that injection plus exercise may be the dominant treatment option. At a willingness to pay of £20,000 per additional QALY gained, there was a 61% probability that injection plus exercise was the most cost-effective option. Injection plus exercise delivered by therapists may be a cost-effective use of resources compared with exercise alone and lead to lower health care costs and less time off work. International Standard Randomised Controlled Trial Number Register, http://www.controlled-trials.com/isrctn/, ISRCT 25817033.

  18. Internal- and External-Rotation Peak Toque in Little League Baseball Players With Subacromial Impingement Syndrome: Improved by Closed Kinetic Chain Shoulder Training.

    Science.gov (United States)

    Lee, Dong-Rour; Kim, Laurentius Jongsoon

    2016-08-01

    Many studies have explored closed kinetic chain (CKC) shoulder exercises (SEs) with a sling because they are safer and more effective than open-chain exercises, especially in early stages of treatment. However, the application of CKC SE in youth baseball players has rarely been attempted, although teenage baseball players also experience shoulder pain. To investigate the effects of CKC SE on the peak torque of shoulder internal rotation (IR) and external rotation (ER) in youth baseball players. Single-group pretest, posttest. Biomechanics laboratory. 23 Little League Baseball players with subacromial impingement syndrome. The CKC SE with a sling was CKC shoulder-flexion exercise, extension exercise, IR exercise, and ER exercise. This exercise regimen was conducted 2 or 3 times/wk for 8 wk. The peak torque of shoulder IR and ER was measured using an isokinetic dynamometer. Concentric shoulder rotation was performed, with 5 repetitions at an angular velocity of 60°/s and 15 at 180°/s. The IR and ER peak torque significantly increased at each angular velocity after the exercise program. In particular, the increase in IR and ER peak torque values was statistically significant at an angular velocity of 180°/s. CKC SE was effective in increasing shoulder IR and ER strength, demonstrating its potential benefits in the prevention and treatment of shoulder injury. In addition, increased IR peak torque appears to improve throwing velocity in baseball players.

  19. Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome.

    Science.gov (United States)

    Nörenberg, Dominik; Armbruster, Marco; Bender, Yi-Na; Walter, Thula; Ebersberger, Hans U; Diederichs, Gerd; Hamm, Bernd; Ockert, Ben; Makowski, Marcus R

    2017-03-01

    To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (pformation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. • SWMR has the potential to reliably identify sub-coracoacromial spurs without radiation exposure. • SWMR provides comparable detection rates to conventional radiography for sub-coracoacromial spur formation. • SWMR yields higher detection rates compared to standard-MR regarding sub-coracoacromial spur formation. • SWMR can be implemented in routine shoulder MRI protocols.

  20. PERBANDINGAN ANTARA KOMBINASI LATIHAN STABILISASI BAHU DAN TRAKSI HUMERUS KE INFERIOR DENGAN KOMBINASI LATIHAN FUNGSIONAL BAHU DAN TRAKSI HUMERUS KE INFERIOR DALAM MENURUNKAN DISABILITAS BAHU DAN LENGAN PADA SUBACROMIAL IMPINGEMENT SYNDROME MAHASISWA AKAD

    Directory of Open Access Journals (Sweden)

    Mawaddah -

    2015-08-01

    Full Text Available Shoulder impingement causing interference on the motion of the shoulder joint activities and result in functional activity disorder. These injuries usually are caused by faulty movement, overuse, poor posture, occupational factors and trauma. This will cause a burden on one part of the body and cause imbalances in anatomy, which will eventually lead to disruption of the body that experienced work. This study aimed to investigate the effect of functional shoulder exercise and traction humerus to inferior with shoulder stabilization exercises and traction humerus to inferior to the decline in the shoulder and arm disabilities in subacromial impingement syndrome. This research method was experimental clinical trials with pre test and post test group design. Population student Academy Physiotherapy Widya Husada Semarang, which consists of 3 men and 12 women, aged between 18-21 years, divided into two groups. Group I was given Shoulder Stabilization exercises and Traction humerus to Inferior (n=7 and group II Functional Shoulder Exercise and Traction humerus to Inferior (n=8. This research was conducted for 3 weeks. Measurement of the value of disability shoulder and arm by using the Shoulder Pain and Disability Index (SPADI. The test results on the group I average value pre 34.17, SB = 6.31, and the average value of post 11.54, SB = 4.02, p = 0.001 found significant differences obtained test results paired sample t-test, and testing group II average value pre 40.18, SB = 3.53, and the average value of post 7.82, SB = 1.57, p = 0.001 found significant differences obtained test results paired sample t-test. Comparison of Group I and II, p = 0.005 there were significant differences, test results obtained independent sample t-test. Conclusions: The combination of shoulder stabilization exercises and traction humerus to inferior can reduce disability shoulder and arm on subacromial impingement syndrome. The combination functional shoulder exercise and

  1. Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Noerenberg, Dominik; Armbruster, Marco [Munich University Hospitals Campus Grosshadern, Department of Clinical Radiology, Munich (Germany); Bender, Yi-Na; Walter, Thula; Diederichs, Gerd; Hamm, Bernd [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); Ebersberger, Hans U. [Heart Center Munich-Bogenhausen, Department of Cardiology and Intensive Care Medicine, Munich (Germany); Ockert, Ben [Munich University Hospitals Campus Grosshadern, Department of Trauma and Orthopedic Surgery, Shoulder and Elbow Service, Munich (Germany); Makowski, Marcus R. [Charite - University Medicine Berlin, Department of Radiology, Berlin (Germany); King' s College London, Division of Imaging Sciences and Biomedical Engineering, London (United Kingdom)

    2017-03-15

    To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (p<0.001). SWMR demonstrated a sensitivity of 97.7 % (CI=0.92-1) and a specificity of 91.3 % (CI=0.788-1) for the identification of spurs. Standard MR-sequences achieved a sensitivity of 47.8 % (CI=0.185-0.775) and a specificity of 80.8 % (CI=0.642-0.978). Size measurements between SWMR and radiography showed a good correlation (R{sup 2}=0.75;p<0.0001), while overestimating lesion size (5.7±1.2 mm; 4.3±1.3 mm;p<0.0001). Interobserver-agreement for spurs was high on SWMR (R{sup 2}=0.74;p<0.0001), but low on standard MRI (R{sup 2}=0.24;p<0.0001). SWMR allows a reliable detection of sub-coracoacromial spur formation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. (orig.)

  2. Diagnostic performance of susceptibility-weighted magnetic resonance imaging for the assessment of sub-coracoacromial spurs causing subacromial impingement syndrome

    International Nuclear Information System (INIS)

    Noerenberg, Dominik; Armbruster, Marco; Bender, Yi-Na; Walter, Thula; Diederichs, Gerd; Hamm, Bernd; Ebersberger, Hans U.; Ockert, Ben; Makowski, Marcus R.

    2017-01-01

    To evaluate the potential of susceptibility-weighted-magnetic-resonance-imaging (SWMR) for the detection of sub-coracoacromial spurs in patients with clinically suspected subacromial impingement syndrome (SAIS), compared to standard MR-sequences and radiographs. Forty-four patients with suspected SAIS were included. All patients underwent radiography, standard MRI of the shoulder and SWMR. Radiograph-based identification of sub-coracoacromial spurs served as goldstandard. Radiographs identified twenty-three spurs in twenty-three patients. Twenty-one patients without spur formation served as reference group. Detection rate, sensitivity/specificity and interobserver-agreements were calculated. Linear regression was applied to determine the relationship between size measurements on radiographs and MRI. Detection rates for spurs on standard MRI and SWMR were 47.8 % and 91.3 % compared to radiography (p<0.001). SWMR demonstrated a sensitivity of 97.7 % (CI=0.92-1) and a specificity of 91.3 % (CI=0.788-1) for the identification of spurs. Standard MR-sequences achieved a sensitivity of 47.8 % (CI=0.185-0.775) and a specificity of 80.8 % (CI=0.642-0.978). Size measurements between SWMR and radiography showed a good correlation (R 2 =0.75;p<0.0001), while overestimating lesion size (5.7±1.2 mm; 4.3±1.3 mm;p<0.0001). Interobserver-agreement for spurs was high on SWMR (R 2 =0.74;p<0.0001), but low on standard MRI (R 2 =0.24;p<0.0001). SWMR allows a reliable detection of sub-coracoacromial spur formation in patients with SAIS and is superior to standard MR-sequences using radiography as goldstandard. (orig.)

  3. Guideline for diagnosis and treatment of subacromial pain syndrome

    NARCIS (Netherlands)

    Diercks, Ronald; Bron, Carel; Dorrestijn, Oscar; Meskers, Carel; Naber, René; de Ruiter, Tjerk; Willems, Jaap; Winters, Jan; van der Woude, Henk Jan

    Treatment of "subacromial impingement syndrome" of the shoulder has changed drastically in the past decade. The anatomical explanation as "impingement" of the rotator cuff is not sufficient to cover the pathology. "Subacromial pain syndrome", SAPS, describes the condition better. A working group

  4. Surgery for subacromial impingement syndrome in relation to occupational exposures, lifestyle factors and diabetes mellitus: a nationwide nested case-control study.

    Science.gov (United States)

    Dalbøge, Annett; Frost, Poul; Andersen, Johan Hviid; Svendsen, Susanne Wulff

    2017-10-01

    To estimate the risk of surgery for subacromial impingement syndrome (SIS) in relation to occupational exposures, lifestyle factors and diabetes mellitus. We conducted a case-control study nested in a register-based cohort study of the Danish working population. For each of 3000 first-time cases of surgery for SIS, two age-matched and sex-matched controls were drawn. Cases and controls received a questionnaire on job history and other factors. Job histories were combined with a psychosocial job exposure matrix (JEM) and the updated Shoulder JEM, which provided exposure intensities on measurement scales. Ten-year cumulative exposures to upper arm elevation >90°, repetitive shoulder movements, forceful shoulder exertions and hand-arm vibrations (HAVs) were estimated. We used conditional logistic regression. There were 5396 persons (60%) who answered the questionnaire. For occupational mechanical exposures, the adjusted OR (OR adj ) ranged from 1.9 (95% CI 1.5 to 2.5 for HAVs) to 2.5 (95% CI 1.9 to 3.5 for force) among men and 1.7 (95% CI 1.2 to 2.5 for HAVs) to 2.0 (95% CI 1.3 to 2.9 for force) among women. No statistically significant associations were found for occupational psychosocial factors. Body mass index (BMI) and pack-years of smoking showed OR adj up to 2.0. Diabetes mellitus showed OR adj of 1.5 (95% CI 1.1 to 2.2) for men and 2.2 (95% CI 1.4 to 3.4) for women. Our findings add to the evidence of an increased risk of surgery for SIS in relation to occupational cumulative mechanical exposures, even when an increased risk in relation to BMI, smoking and diabetes mellitus is taken into account. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Impingement syndrome of the shoulder

    International Nuclear Information System (INIS)

    Mayerhoefer, M.E.; Breitenseher, M.J.

    2004-01-01

    The impingement syndrome is a clinical entity characterized by shoulder pain due to primary or secondary mechanical irritation of the rotator cuff. The primary factors for the development of impingement are a curved or hook-shaped anterior acromion as well as subacromial osteophytes, which may lead to tearing of the supraspinatus tendon. Secondary impingement is mainly caused by calcific tendinopathy, glenohumeral instability, os acromiale and degenerative changes of the acromioclavicular joint. Conventional radiographs are initially obtained, mainly for evaluation of the bony structures of the shoulder. If available, sonography can be used for detection of lesions and tears of the rotator cuff. Finally, MR-imaging provides detailed information about the relationship of the acromion and the acromioclavicular joint to the rotator cuff itself. In many cases however, no morphologic cause for impingement syndrome can be found. While patients are initially treated conservatively, chronic disease usually requires surgical intervention. (orig.) [de

  6. Physiotherapy after subacromial decompression surgery

    DEFF Research Database (Denmark)

    Christiansen, David Høyrup; Falla, Deborah; Frost, Poul

    2015-01-01

    This paper describes the development and details of a standardised physiotherapy exercise intervention designed to address pain and disability in patients with difficulty returning to usual activities after arthroscopic decompression surgery for subacromial impingement syndrome. To develop...... the intervention, the literature was reviewed with respect to the effectiveness of postoperative exercises, components of previous exercise programmes were extracted, and input from clinical physiotherapists in the field was obtained through a series of workshops. The physiotherapy exercise intervention...

  7. Guideline for diagnosis and treatment of subacromial pain syndrome: a multidisciplinary review by the Dutch Orthopaedic Association

    NARCIS (Netherlands)

    Diercks, R.; Bron, C.; Dorrestijn, O.; Meskers, C.; Naber, R.; Ruiter, T. de; Willems, J.; Winters, J.; Woude, H.J. van der; et al.,

    2014-01-01

    Treatment of "subacromial impingement syndrome" of the shoulder has changed drastically in the past decade. The anatomical explanation as "impingement" of the rotator cuff is not sufficient to cover the pathology. "Subacromial pain syndrome", SAPS, describes the condition better. A working group

  8. Role of coherent structures in supersonic impinging jetsa)

    Science.gov (United States)

    Kumar, Rajan; Wiley, Alex; Venkatakrishnan, L.; Alvi, Farrukh

    2013-07-01

    This paper describes the results of a study examining the flow field and acoustic characteristics of a Mach 1.5 ideally expanded supersonic jet impinging on a flat surface and its control using steady microjets. Emphasis is placed on two conditions of nozzle to plate distances (h/d), of which one corresponds to where the microjet based active flow control is very effective in reducing flow unsteadiness and near-field acoustics and the other has minimal effectiveness. Measurements include unsteady pressures, nearfield acoustics using microphone and particle image velocimetry. The nearfield noise and unsteady pressure spectra at both h/d show discrete high amplitude impinging tones, which in one case (h/d = 4) are significantly reduced with control but in the other case (h/d = 4.5) remain unaffected. The particle image velocimetry measurements, both time-averaged and phase-averaged, were used to better understand the basic characteristics of the impinging jet flow field especially the role of coherent vortical structures in the noise generation and control. The results show that the flow field corresponding to the case of least control effectiveness comprise well defined, coherent, and symmetrical vortical structures and may require higher levels of microjet pressure supply for noise suppression when compared to the flow field more responsive to control (h/d = 4) which shows less organized, competing (symmetrical and helical) instabilities.

  9. Conservative treatment for patients with subacromial impingement

    DEFF Research Database (Denmark)

    Clausen, Mikkel B; Merrild, Mikas B; Witten, Adam

    2018-01-01

    -injections was recorded at follow-up. Changes in outcomes were analyzed using Wilcoxon Signed-Rank test, and the corresponding effect sizes (ES) were estimated. The associations between changes in outcomes and rehabilitation parameters were explored using multiple regression analyses. Results: Sixty-three patients....... The outcomes Shoulder Pain and Disability Index (SPADI:0-100), average pain (NRS:0-10), external rotation strength, abduction strength and abduction ROM, pain during each test (NRS:0-10), were collected at baseline and at six month follow-up. Amount of exercise-time, physio-sessions and steroid...... completed both baseline and follow-up testing. Significant improvements were seen in SPADI (19 points, ES:0.53, p 0.2). A higher number of physio-sessions was significantly associated...

  10. Diagnosis of shoulder impingement syndrome

    International Nuclear Information System (INIS)

    Hodler, J.

    1996-01-01

    This article reviews the pathogenesis and clinical and imaging findings in shoulder impingement syndrome. Different stages of impingement syndrome are described. Stage I relates to edema and hemorrhage of the supraspinatus tendon. Stage II is characterized by bursal inflammation and fibrosis, as well as tendinopathy. In stage III there is a tear of the rotator cuff. Clinical signs many overlap. Moreover, calcifying tendinitis, fractures and pain originating from the cervical spine may mimic shoulder impingement syndrome. Imaging is important for the exact diagnosis. Standard radiographs are the basis of imaging in shoulder impingement syndrome. They may demonstrate subchondral sclerosis of the major tuberosity, subacromial spurs, and form anomalies of the acromion. They are also important in the differential diagnosis of shoulder impingement syndrome and demonstrate calcifying tendinitis, fractures and neoplasm. Ultrasonography has found acceptance as a screening tool and even as a final diagnostic method by many authors. However, there is a high interobserver variability in the demonstration of rotator cuff tears. Its usefulness has therefore been questioned. MR imaging is probably the method of choice in the evaluation of the rotator cuff and surrounding structures. Several investigations have demonstrated that differentiation of early findings, such as tendinopathy versus partial tears, may be difficult with MR imaging. However, reproducibility for fullthickness tears appears to be higher than for sonography. Moreover, specificity appears to be superior to sonography. MR arthrography is not universally accepted. However, it allows for more exact differentiation of discrete findings and may be indicated in preoperative planning. Standard arthrography and CT have a limited role in the current assessment of the rotator cuff. (orig.) [de

  11. Subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder manual therapy plus exercise intervention in individuals with subacromial impingement syndrome: a prospective, randomized controlled clinical trial pilot study.

    Science.gov (United States)

    Wright, Alexis A; Donaldson, Megan; Wassinger, Craig A; Emerson-Kavchak, Alicia J

    2017-09-01

    To determine the subacute effects of cervicothoracic spinal thrust/non-thrust in addition to shoulder non-thrust plus exercise in patients with subacromial pathology. This was a randomized, single blinded controlled trial pilot study. This trial was registered at ClinicalTrials.gov (NCT01753271) and reported according to Consolidated Standards of Reporting Trials requirements. Patients were randomly assigned to either shoulder treatment plus cervicothoracic spinal thrust/non-thrust or shoulder treatment-only group. Primary outcomes were average pain intensity (Numeric Pain Rating Scale) and physical function (Shoulder Pain and Disability Index) at 2 weeks, 4 weeks, and patient discharge. 18 patients, mean age 43.1(15.8) years satisfied the eligibility criteria and were analyzed for follow-up data. Both groups showed statistically significant improvements in both pain and function at 2 weeks, 4 weeks, and discharge. The between-group differences for changes in pain or physical function were not significant at any time point. The addition of cervicothoracic spinal thrust/non-thrust to the shoulder treatment-only group did not significantly alter improvement in pain or function in patients with subacromial pathology. Both approaches appeared to provide an equally notable benefit. Both groups improved on all outcomes and met the criteria for clinical relevance for both pain and function. 2b.

  12. Shouldering the blame for impingement: the rotator cuff continuum ...

    African Journals Online (AJOL)

    The aim of this article was to summarise recent research on shoulder impingement and rotator cuff pathology. A continuum model of rotator cuff pathology is described, and the challenges of accurate clinical diagnosis, imaging and best management discussed. Keywords: shoulder impingement syndrome, subacromial ...

  13. Impingement syndrome of the shoulder; Schulterimpingement

    Energy Technology Data Exchange (ETDEWEB)

    Mayerhoefer, M.E. [Klinische Abteilung fuer Osteologie, Klinik fuer Radiodiagnostik der Universitaet Wien (Austria); Klinische Abteilung Radiodiagnostik fuer chirurgische Faecher, Klinik fuer Radiodiagnostik der Universitaet Wien (Austria); Klinische Abteilung fuer Osteologie, Klinik fuer Radiodiagnostik der Universitaet, Waehringer Guertel 18-20, 1090, Wien (Austria); Breitenseher, M.J. [Klinische Abteilung fuer Osteologie, Klinik fuer Radiodiagnostik der Universitaet Wien (Austria); Waldviertelklinikum Horn (Austria)

    2004-06-01

    The impingement syndrome is a clinical entity characterized by shoulder pain due to primary or secondary mechanical irritation of the rotator cuff. The primary factors for the development of impingement are a curved or hook-shaped anterior acromion as well as subacromial osteophytes, which may lead to tearing of the supraspinatus tendon. Secondary impingement is mainly caused by calcific tendinopathy, glenohumeral instability, os acromiale and degenerative changes of the acromioclavicular joint. Conventional radiographs are initially obtained, mainly for evaluation of the bony structures of the shoulder. If available, sonography can be used for detection of lesions and tears of the rotator cuff. Finally, MR-imaging provides detailed information about the relationship of the acromion and the acromioclavicular joint to the rotator cuff itself. In many cases however, no morphologic cause for impingement syndrome can be found. While patients are initially treated conservatively, chronic disease usually requires surgical intervention. (orig.) [German] Das Impingementsyndrom ist ein klinisches Krankheitsbild multifaktorieller Genese, bei dem es primaer oder sekundaer zu einer schmerzhaften mechanischen Beeintraechtigung der Rotatorenmanschette kommt. Als primaere Faktoren gelten ein gebogener oder hakenfoermiger Vorderrand des Akromions oder von diesem entspringende Osteophyten, was zu Laesionen der Supraspinatussehne fuehren kann. Zu den sekundaeren Faktoren zaehlt man v. a. eine Tendinitis calcarea, eine glenohumerale Instabilitaet, ein Os acromiale sowie degenerative Veraenderungen im Bereich des Akromioklavikulargelenks. Bildgebend steht an erster Stelle ein Nativroentgen, mit dem sich die knoechernen Strukturen gut darstellen lassen. Falls vorhanden, kann in weiterer Folge die Sonographie Auskunft ueber den Zustand der Rotatorenmanschette geben. Mit der MRT schliesslich laesst sich die Beziehung von Akromion und gelenkassoziierten Strukturen zur Rotatorenmanschette

  14. Vortex Structure Effects on Impingement, Effusion, and Cross Flow Cooling of a Double Wall Configuration

    Science.gov (United States)

    Ligrani, P. M.

    2018-03-01

    A variety of different types of vortices and vortex structures have important influences on thermal protection, heat transfer augmentation, and cooling performance of impingement cooling, effusion cooling, and cross flow cooling. Of particular interest are horseshoe vortices, which form around the upstream portions of effusion coolant concentrations just after they exit individual holes, hairpin vortices, which develop nearby and adjacent to effusion coolant trajectories, and Kelvin-Helmholtz vortices which form within the shear layers that form around each impingement cooling jet. The influences of these different vortex structures are described as they affect and alter the thermal performance of effusion cooling, impingement cooling, and cross flow cooling, as applied to a double wall configuration.

  15. Arthroscopic Resection of The Distal Clavicle With Concomitant Subacromial Decompression: A Case Series

    Directory of Open Access Journals (Sweden)

    HZ Chan

    2014-07-01

    Full Text Available Shoulder impingement syndrome and acromioclavicular joint osteoarthritis often occur simultaneously and easily missed. Kay et al. reported excellent results with combined arthroscopic subacromial decompression and resection of the distal end of the clavicle in patients with both disorders. Arthroscopic treatment of these disorders produces more favourable results than open procedures. We report two patients who were not responding to conservative management and were treated with direct arthroscopic distal clavicle excision and subacromial decompression in single setting. Both patients gained good postoperative outcome in terms of pain score, function and strength improvement assessed objectively with visual analogue score (VAS and University of California Los Angeles Score (UCLA.

  16. Hydrodynamics of layer structured targets impinged by intense ion beams

    International Nuclear Information System (INIS)

    Davila, J.; Barrero, A.

    1989-01-01

    To minimize the energy loss in the corona outflow, a layer structured spherical hollow shell has been proposed to be used as target in inertial confinement fusion. For ion beam drivers, the major part of the beam energy is absorbed in the middle layer, which is called either absorber or pusher. The outer layer, called tamper, slows down the outward expansion of the absorbed low density region. The materials of the tamper and pusher are usually in the inner layer. The knowledge of the hydrodynamics of the interaction of an intense beam with a structured target is then an essential point in order to achieve break-even conditions in ion-beam fusion. (author) 2 refs., 2 figs

  17. Shoulder impingement syndrome: diagnostic accuracy of magnetic resonance imaging and radiographic signs

    International Nuclear Information System (INIS)

    Williamson, M.P.; Chandnani, V.P.; Baird, D.E.; Deberardino, T.M.; Swenson, G.W.; Hansen, M.F.

    1994-01-01

    Shoulder impingement syndrome is commonly encountered in orthopaedics. In a blinded retrospective study, magnetic resonance imaging and roentgenographic signs in 41 patients with clinical signs of impingement syndrome were compared with 40 control patients. Statistically significant differences between the groups included the absence of subacromial fat, as well as the presence of a supraspinatus tear, subacromial osteophytes, and a decreased coracohumeral distance. Other signs reported to occur in patients with impingement syndrome did not vary significantly in the population studied. 20 refs., 12 figs

  18. Impingement: an annotated bibliography

    International Nuclear Information System (INIS)

    Uziel, M.S.; Hannon, E.H.

    1979-04-01

    This bibliography of 655 annotated references on impingement of aquatic organisms at intake structures of thermal-power-plant cooling systems was compiled from the published and unpublished literature. The bibliography includes references from 1928 to 1978 on impingement monitoring programs; impingement impact assessment; applicable law; location and design of intake structures, screens, louvers, and other barriers; fish behavior and swim speed as related to impingement susceptibility; and the effects of light, sound, bubbles, currents, and temperature on fish behavior. References are arranged alphabetically by author or corporate author. Indexes are provided for author, keywords, subject category, geographic location, taxon, and title

  19. Femoroacetabular impingement

    International Nuclear Information System (INIS)

    Kassarjian, Ara; Brisson, Melanie; Palmer, William E.

    2007-01-01

    Femoroacetabular impingement is a relatively recently appreciated 'idiopathic' cause of hip pain and degenerative change. Two types of impingement have been described. The first, cam impingement, is the result of an abnormal morphology of the proximal femur, typically at the femoral head-neck junction. Cam impingement is most common in young athletic males. The second, pincer impingement, is the result of an abnormal morphology or orientation of the acetabulum. Pincer impingement is most common in middle-aged women. This article reviews the imaging findings of cam and pincer type femoroacetabular impingement. Recognition of these entities will help in the selection of the appropriate treatment with the goal of decreasing the likelihood of early degenerative change of the hip

  20. Internal Impingement of the Shoulder: A Risk of False Positive Test Outcomes in External Impingement Tests?

    Directory of Open Access Journals (Sweden)

    Tim Leschinger

    2017-01-01

    Full Text Available Background. External impingement tests are considered as being particularly reliable for identifying subacromial and coracoid shoulder impingement mechanisms. The purpose of the present study was to evaluate if these tests are likely to provoke an internal shoulder impingement mechanism which, in cases of a pathologic condition, can lead to a positive test result. Method. In 37 subjects, the mechanical contact between the glenoid rim and the rotator cuff (RC was measured quantitatively and qualitatively in external impingement test positions using an open MRI system. Results. Mechanical contact of the supraspinatus with the posterosuperior glenoid was present in 30 subjects in the Neer test. In the Hawkins test, the subscapularis was in contact with the anterosuperior glenoid in 33 subjects and the supraspinatus in 18. In the horizontal impingement test, anterosuperior contact of the supraspinatus with the glenoid was identified in 35 subjects. Conclusion. The Neer, Hawkins, and horizontal impingement tests are likely to provoke the mechanism of an internal shoulder impingement. A posterosuperior internal impingement mechanism is being provoked predominately in the Neer test. The Hawkins test narrows the distance between the insertions of the subscapularis and supraspinatus and the anterosuperior labrum, which leads to an anterosuperior impingement mechanism.

  1. The effect of scapular position on subacromial contact behavior: a cadaver study.

    Science.gov (United States)

    Muraki, Takayuki; Yamamoto, Nobuyuki; Sperling, John W; Steinmann, Scott P; Cofield, Robert H; An, Kai-Nan

    2017-05-01

    Patients with subacromial impingement were reported to show abnormal scapular positions during shoulder elevation. However, the relationship between the scapular positions and subacromial impingement is unclear. The purpose of this study was to biomechanically determine the effect of scapular position on subacromial contact behavior by using fresh frozen cadavers. The peak contact pressure on the coracoacromial arch was measured with a flexible tactile force sensor in 9 fresh frozen cadaver shoulders. The measurement was performed during passive glenohumeral elevation in the scapular plane ranging from 30° to 75°. The scapular downward and internal rotations and anterior tilt were simulated by tilting the scapula in 5° increments up to 20°. The measurement was also performed with combination of scapular downward and internal rotations and anterior tilt positions. The peak contact pressure decreased linearly with anterior tilt, and a significant difference between neutral scapular position (1.06 ± 0.89 MPa) and anterior tilt by 20° (0.46 ± 0.18 MPa) was observed (P < .05). However, the scapular positioning in the other directions did not change the peak contact pressure significantly. Furthermore, any combination of abnormal scapular positions did not affect peak contact pressure significantly. Scapular anterior tilt decreased peak contact pressure during passive shoulder elevation. In addition, scapular downward and internal rotations had little effect on peak contact pressure. The abnormal scapular motion reported in previous studies might not be directly related to symptoms caused by subacromial impingement. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  2. MR imaging after therapeutic injection of the subacromial bursa

    Energy Technology Data Exchange (ETDEWEB)

    Major, N.M. [Duke University Medical Center, Department of Radiology, Division Musculoskeletal, Durham, NC (United States)

    1999-11-01

    Objective. As a therapeutic injection into the subacromial bursa (SAB) is commonly performed for impingement syndrome, it is important to know whether this fluid can be retained for a period of time and cause confusion with a pathologic collection of fluid. This study identifies and describes the appearance of recent subacromial injection using MR imaging, and the appearance of a potential complication.Design and patients. Fourteen asymptomatic shoulders were studied with MR imaging using fast spin echo T2-weighted imaging (1.5 T) prior to injection with 7 cm{sup 3} of xylocaine. Four shoulders had subacromial fluid and were eliminated from the study. The remaining 10 (9 men, 1 woman; age range 27-36 years, average age 33 years) were then re-imaged immediately, and at 6, 12 and 24 h after the injection or until fluid resolved. Each set of images was reviewed for the presence of fluid in the SAB and for additional abnormalities.Results. Fluid was identified in all subjects in the SAB in the immediate, 6 and 12 h post-injection images. At 24 h, fluid was not identified within the SAB in eight of 10 patients. In one patient fluid resolved in 48 h. The other continued to demonstrate fluid in the SAB and in the joint as well as abnormal signal in the infraspinatus muscle from a presumed myositis. Imaging was performed up to 10 days after the injection in this patient.Conclusions. It is known that fluid identified in the SAB without evidence of a cuff tear may be due to bursitis. However, if MR imaging is performed within 24 h of injection, the presence of the fluid may be iatrogenic. In addition, the history of recent therapeutic injection is very important as complications such as myositis can occur as a result of the injection. Knowledge of injection prior to imaging is vital for accurate interpretation of MR shoulder examinations. (orig.)

  3. MR imaging after therapeutic injection of the subacromial bursa

    International Nuclear Information System (INIS)

    Major, N.M.

    1999-01-01

    Objective. As a therapeutic injection into the subacromial bursa (SAB) is commonly performed for impingement syndrome, it is important to know whether this fluid can be retained for a period of time and cause confusion with a pathologic collection of fluid. This study identifies and describes the appearance of recent subacromial injection using MR imaging, and the appearance of a potential complication.Design and patients. Fourteen asymptomatic shoulders were studied with MR imaging using fast spin echo T2-weighted imaging (1.5 T) prior to injection with 7 cm 3 of xylocaine. Four shoulders had subacromial fluid and were eliminated from the study. The remaining 10 (9 men, 1 woman; age range 27-36 years, average age 33 years) were then re-imaged immediately, and at 6, 12 and 24 h after the injection or until fluid resolved. Each set of images was reviewed for the presence of fluid in the SAB and for additional abnormalities.Results. Fluid was identified in all subjects in the SAB in the immediate, 6 and 12 h post-injection images. At 24 h, fluid was not identified within the SAB in eight of 10 patients. In one patient fluid resolved in 48 h. The other continued to demonstrate fluid in the SAB and in the joint as well as abnormal signal in the infraspinatus muscle from a presumed myositis. Imaging was performed up to 10 days after the injection in this patient.Conclusions. It is known that fluid identified in the SAB without evidence of a cuff tear may be due to bursitis. However, if MR imaging is performed within 24 h of injection, the presence of the fluid may be iatrogenic. In addition, the history of recent therapeutic injection is very important as complications such as myositis can occur as a result of the injection. Knowledge of injection prior to imaging is vital for accurate interpretation of MR shoulder examinations. (orig.)

  4. Subacromial shoulder disorders among baggage handlers

    DEFF Research Database (Denmark)

    Thygesen, Lau Caspar; Mikkelsen, Sigurd; Pedersen, Ellen Bøtker

    2016-01-01

    PURPOSE: To assess the influence of cumulative employment as baggage handler on the risk of incident subacromial shoulder disorders. Baggage handling is characterized by repetitive work primarily consisting of heavy lifting in awkward positions and time pressure. METHODS: This cohort study is based...... increased incidence of subacromial shoulder disorders for workers with longer cumulative years of employment. These results support that long-term lifting in awkward positions and time pressure influences the risk of subacromial shoulder disorders....... System. The primary exposure was cumulative years of employment as a baggage handler, and the primary outcome was diagnoses and surgical treatment of subacromial shoulder disorders. RESULTS: The cohort contained 3396 baggage handlers and 63,909 workers in the reference group. Baggage handlers with longer...

  5. Shoulder impingement syndrome : evaluation of the causes with MRI

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Ho; Song, In Sup; Chung, Hun Young; Yoon, Sang Jin; Kim, Yang Soo; Shim, Hyung Jin; Choi, Young Hee; Lee, Jong Beum; Lee, Yong Chul; Kim, Kun Sang [Chungang Univ. College of Medicine, Seoul (Korea, Republic of); Choi, Yun Sun [Eulji Hospital, College of Medicine, Seoul (Korea, Republic of)

    1999-12-01

    Various mechanical causes which induce shoulder impingement syndrome have been identified with the help of MRI. The aim of this study is to evaluate the incidence of such causes. A total of 54 patients with clinically confirmed shoulder impingement syndrome and a normal control group(n=20) without symptoms were included. We evaluated the incidence of hook shaped acromion, low lying acromion, downward slope of the acromion, subacromial spur, acromioclavicular joint hypertrophy, coracoacromial ligament hypertrophy, high cuff muscle bulk, and os acromiale. Among the 54 patients, the following conditions were present: acromioclavicular joint hypertrophy(n=36), coracoacromial ligament hypertrophy(n=20), subacromial spur(n=18), downward sloping of the acromion(n=16), hook shaped acromion(n=11), relatively high cuff muscle bulk(n=6), low lying acromion relative to the clavicle(n=3), and os acromiale(n=1). In the normal control group there were nine cases of acromioclavicular joint hypertrophy, nine of coracoacromial ligament hypertrophy, nine of downward sloping acromion, and three of low lying acromion, but hook shaped acromion, high cuff muscle bulk, and os acromiale were not found. Among 54 patients, the syndrome was due to five simultancous causes in one patient, four causes in two, three causes in 12, two causes in 22, and one cause in 17. Hook shaped acromion and subacromial spur are the statistically significant causes of shoulder impingement syndrome. In 69% of patients, the condition was due to more than one cause.

  6. Shoulder impingement syndrome : evaluation of the causes with MRI

    International Nuclear Information System (INIS)

    Choi, Yong Ho; Song, In Sup; Chung, Hun Young; Yoon, Sang Jin; Kim, Yang Soo; Shim, Hyung Jin; Choi, Young Hee; Lee, Jong Beum; Lee, Yong Chul; Kim, Kun Sang; Choi, Yun Sun

    1999-01-01

    Various mechanical causes which induce shoulder impingement syndrome have been identified with the help of MRI. The aim of this study is to evaluate the incidence of such causes. A total of 54 patients with clinically confirmed shoulder impingement syndrome and a normal control group(n=20) without symptoms were included. We evaluated the incidence of hook shaped acromion, low lying acromion, downward slope of the acromion, subacromial spur, acromioclavicular joint hypertrophy, coracoacromial ligament hypertrophy, high cuff muscle bulk, and os acromiale. Among the 54 patients, the following conditions were present: acromioclavicular joint hypertrophy(n=36), coracoacromial ligament hypertrophy(n=20), subacromial spur(n=18), downward sloping of the acromion(n=16), hook shaped acromion(n=11), relatively high cuff muscle bulk(n=6), low lying acromion relative to the clavicle(n=3), and os acromiale(n=1). In the normal control group there were nine cases of acromioclavicular joint hypertrophy, nine of coracoacromial ligament hypertrophy, nine of downward sloping acromion, and three of low lying acromion, but hook shaped acromion, high cuff muscle bulk, and os acromiale were not found. Among 54 patients, the syndrome was due to five simultancous causes in one patient, four causes in two, three causes in 12, two causes in 22, and one cause in 17. Hook shaped acromion and subacromial spur are the statistically significant causes of shoulder impingement syndrome. In 69% of patients, the condition was due to more than one cause

  7. Femoroacetabular impingement

    International Nuclear Information System (INIS)

    Anderson, Suzanne E.; Siebenrock, Klaus Arno; Tannast, Moritz

    2012-01-01

    Femoroacetabular impingement (FAI) is a pathomechanical concept describing the early and painful contact of morphological changes of the hip joint, both on the acetabular, and femoral head sides. These can lead clinically to symptoms of hip and groin pain, and a limited range of motion with labral, chondral and bony lesions. Pincer impingement generally involves the acetabular side of the joint where there is excessive coverage of the acetabulum, which may be focal or more diffuse. There is linear contact of the acetabulum with the head/neck junction. Cam impingement involves the femoral head side of the joint where the head is associated with bony excrescences and is aspheric. The aspheric femoral head jams into the acetabulum. Imaging appearances are reviewed below. This type is evident in young males in the second and third decades. The main features of FAI are described.

  8. Diagnosis of shoulder impingement syndrome; Diagnostik des Schulterimpingementsyndroms

    Energy Technology Data Exchange (ETDEWEB)

    Hodler, J. [Orthopaedische Universitaetsklinik Balgrist, Zuerich (Switzerland)

    1996-12-01

    This article reviews the pathogenesis and clinical and imaging findings in shoulder impingement syndrome. Different stages of impingement syndrome are described. Stage I relates to edema and hemorrhage of the supraspinatus tendon. Stage II is characterized by bursal inflammation and fibrosis, as well as tendinopathy. In stage III there is a tear of the rotator cuff. Clinical signs many overlap. Moreover, calcifying tendinitis, fractures and pain originating from the cervical spine may mimic shoulder impingement syndrome. Imaging is important for the exact diagnosis. Standard radiographs are the basis of imaging in shoulder impingement syndrome. They may demonstrate subchondral sclerosis of the major tuberosity, subacromial spurs, and form anomalies of the acromion. They are also important in the differential diagnosis of shoulder impingement syndrome and demonstrate calcifying tendinitis, fractures and neoplasm. Ultrasonography has found acceptance as a screening tool and even as a final diagnostic method by many authors. However, there is a high interobserver variability in the demonstration of rotator cuff tears. Its usefulness has therefore been questioned. MR imaging is probably the method of choice in the evaluation of the rotator cuff and surrounding structures. Several investigations have demonstrated that differentiation of early findings, such as tendinopathy versus partial tears, may be difficult with MR imaging. However, reproducibility for fullthickness tears appears to be higher than for sonography. Moreover, specificity appears to be superior to sonography. MR arthrography is not universally accepted. However, it allows for more exact differentiation of discrete findings and may be indicated in preoperative planning. Standard arthrography and CT have a limited role in the current assessment of the rotator cuff. (orig.) [Deutsch] Grundlage des Impingementsyndroms ist eine Kompression des Supraspinatus am akromioklavikularen Bogen vor allem bei Flexion

  9. Fluid Signal Intensity That Mimicked A Supraspinatus Tendon Tear In A Subacromial Injected Shoulder: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hun; Kim, Tae Eun; Shin, Hyun Woong [Daegu Fatima Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Subacromial steroid injections are a common procedure for treating shoulder pain. Several studies have reported on the difficulty of performing an accurate injection into the subacromial bursa, as well as the injected material infiltrated into other regional structures even when an accurate injection was done into the subacromial space. These misplacements, and especially in the rotator cuff, creates high signal intensity on T2WI that can mimic a rotator cuff tear. Bergman and Fredericson found that the bursal and extrabursal fluid is resolved or decreased 3 days after the injection, so they recommended a 3-day delay after the shoulder injection before performing MRI to prevent misinterpretation of the signal changes. We report here on a case of a false fullthickness tear of the supraspinatus tendon on MRI one month after subacromial injection, and the supraspinatus tendon turned out to be intact on the follow up ultrasonography and arthroscopic examination

  10. Radiotherapy for shoulder impingement; Bestrahlung beim Impingementsyndrom des Schultergelenks

    Energy Technology Data Exchange (ETDEWEB)

    Adamietz, B. [Universitaetsklinikum Erlangen (Germany). Inst. fuer Radiologie; Sauer, R.; Keilholz, L. [Universitaetsklinikum Erlangen (Germany). Strahlentherapeutische Klinik

    2008-05-15

    Background and Purpose: Up to now, degenerative shoulder diseases were summarized by the term 'periarthritis humeroscapularis'. Actual shoulder diseases can be differentiated etiopathologically according to a primary and secondary impingement syndrome. Narrowing of the subacromial space, which is caused by an osseous shape variant, leads to primary impingement. Secondary impingement develops, when the subacromial space is reduced by swelling tissue below the osseous shoulder roof. This study aimed for the exact diagnosis to indicate therapy and to classify the results according to the Constant score. Patients and Methods: From August 1999 to September 2002, 102 patients with 115 shoulder joint conditions underwent radiation therapy (RT). All joints received two RT series (6 x 0.5 Gy/series) applied in two to three weekly fractions, totaling a dosage of 6.0 Gy (250 kV, 15 mAs, 1-mm Cu filter). The second RT course started 6 weeks after the end of the first. 115 shoulders were examined before RT, 6 weeks after the second RT course and, finally, during the follow-up from January to May 2003. Results: Pain relief was achieved in 94/115 shoulder joints (82%) after 18-month follow-up (median). A significant difference existed between secondary impingement and primary/non-impingement according to response. Tendinosis calcarea, bursitis subdeltoidea, tendovaginitis of the long biceps tendon, and capsulitis adhaesiva responded well to therapy. Conclusion: Shoulder diseases of secondary impingement demonstrate a good response to RT. Less or no benefit was found in primary impingement syndrome or complete rotator cuff disruption and acute shoulder injuries, respectively. (orig.)

  11. Isolated subacromial bursal fluid on MRI of the shoulder in symptomatic patients: correlation with arthroscopic findings

    Energy Technology Data Exchange (ETDEWEB)

    Monu, J.U.V. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Pruett, S. [Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Vanarthos, W.J. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States); Pope, T.L. Jr. [Dept. of Radiology, Bowman Gray School of Medicine, Wake Forest Univ., Winston-Salem, NC (United States)

    1994-10-01

    Fluid in the subacromial bursa (SAB) is a common finding on magnetic resonance (MR) images of the shoulder, and the implications of this finding have not been clarified. We retrospectively reviewed and correlated the MR features with arthroscopic findings in 21 symptomatic patients who had fluid in the SAB on MR imaging without demonstrable rotator cuff tear. Rotator cuff impingement was the most frequent surgical finding (42.9%). Other frequent surgical observations were glenbid labrum abnormality (28.6%), bursitis (19%), and supraspinatus tendinitis (14.3%). Distribution of acromial types was similar to that reported by Bigliani et al., and impingement was evenly distributed among acromial types in our study population. We conclude that in our patient population group the MR finding of isolated SAB fluid in symptomatic patients is highly likely to be associated with the finding of other abnormalities in the shoulder joint at surgery. (orig.)

  12. Isolated subacromial bursal fluid on MRI of the shoulder in symptomatic patients: correlation with arthroscopic findings

    International Nuclear Information System (INIS)

    Monu, J.U.V.; Pruett, S.; Vanarthos, W.J.; Pope, T.L. Jr.

    1994-01-01

    Fluid in the subacromial bursa (SAB) is a common finding on magnetic resonance (MR) images of the shoulder, and the implications of this finding have not been clarified. We retrospectively reviewed and correlated the MR features with arthroscopic findings in 21 symptomatic patients who had fluid in the SAB on MR imaging without demonstrable rotator cuff tear. Rotator cuff impingement was the most frequent surgical finding (42.9%). Other frequent surgical observations were glenbid labrum abnormality (28.6%), bursitis (19%), and supraspinatus tendinitis (14.3%). Distribution of acromial types was similar to that reported by Bigliani et al., and impingement was evenly distributed among acromial types in our study population. We conclude that in our patient population group the MR finding of isolated SAB fluid in symptomatic patients is highly likely to be associated with the finding of other abnormalities in the shoulder joint at surgery. (orig.)

  13. Flow Structure and Heat Transfer of Jet Impingement on a Rib-Roughened Flat Plate

    Directory of Open Access Journals (Sweden)

    Abdulrahman H. Alenezi

    2018-06-01

    Full Text Available The jet impingement technique is an effective method to achieve a high heat transfer rate and is widely used in industry. Enhancing the heat transfer rate even minimally will improve the performance of many engineering systems and applications. In this numerical study, the convective heat transfer process between orthogonal air jet impingement on a smooth, horizontal surface and a roughened uniformly heated flat plate is studied. The roughness element takes the form of a circular rib of square cross-section positioned at different radii around the stagnation point. At each location, the effect of the roughness element on heat transfer rate was simulated for six different heights and the optimum rib location and rib dimension determined. The average Nusselt number has been evaluated within and beyond the stagnation region to better quantify the heat transfer advantages of ribbed surfaces over smooth surfaces. The results showed both flow and heat transfer features vary significantly with rib dimension and location on the heated surface. This variation in the streamwise direction included both augmentation and decrease in heat transfer rate when compared to the baseline no-rib case. The enhancement in normalized averaged Nusselt number obtained by placing the rib at the most optimum radial location R/D = 2 was 15.6% compared to the baseline case. It was also found that the maximum average Nusselt number for each location was achieved when the rib height was close to the corresponding boundary layer thickness of the smooth surface at the same rib position.

  14. The analysis of spatial relationship between the rotator cuff and the subacromial space in different arm positions

    International Nuclear Information System (INIS)

    Zou Yuefen; Wang Dehang; Wang Xiaoning; Li Shener

    2003-01-01

    Objective: To explore the distance between the acromion and the humerus head at different arm abduction to observe whether it changes or not, to determine at which position the distance is smallest, and to evaluate the relationship between the subacromial space and the rotator cuff. Methods: Fifteen normal volunteers were examined with MRI in six arm positions, and the coronal thin images were obtained with a spin echo sequence. Using a special positioning device, the arm was placed at 0 degree, 30 degree, 60 degree, 90 degree, 120 degree and 150 degree arm abduction, respectively. Of them, 0 degree-90 degree positions were not rotated, while 120 degree and 150 degree positions were slight internal rotated. The minimal distance of acromion-humerus (A-H) and clavicle-humerus (C-H), and the spatial relationship between the rotator cuff and the subacromial space were measured and observed. Results: The values of A-H and C-H at 60 degree - 150 degree arm abduction were obviously smaller than those at 0 degree-30 degree arm abduction (P 0.05). The rotator cuff (mainly supraspinatus tendon) just went through between the acromion and the humerus at 60 degree - 120 degree arm positions but not at 0 degree, 30 degree and 150 degree arm positions. So at 60 degree - 120 degree arm positions, rotator cuff between the humerus and the acromion was often impinged. Conclusion: The closest contact between the supraspinatus tendon and subacromial space occurs at 60 degree - 120 degree abduction. The findings testify that the patients with impingement syndrome have shoulder pain at 60 degree - 120 degree abduction in clinic from etiology and pathology. In the future, MRI-based analyses should allow investigating the morphological basis of the impingement syndrome, choosing the appropriate therapy, and minimizing failure rates of surgery

  15. Acromion types and role of corticosteroid with shoulder impingement syndrome

    International Nuclear Information System (INIS)

    Akram, M.; Gillani, S.F.U.S.; Awais, S.M.

    2016-01-01

    To determine the association between shoulder impingement and morphological characteristics of acromion and the role of sub-acromial injection of methylprednisolone in the short-term treatment for relieving pain and improve functional disability of these patients. Study Design: A descriptive study. Place and Duration of Study: Department of Orthopedic Surgery and Traumatology Unit-I (DOST-I), Mayo Hospital, Lahore, between November 2013 to June 2014. Methodology: All patients presented in OPD with shoulder pain were included as subjects and evaluated by clinical test and categorised using X-ray scapula Y-view. Patients with impingement syndrome were correlated with Bigliani types and offered intra-lesional injection into sub-acromial space with 2ml of xylocaine 2% and 40 mg of methylprednisolone using 22 gauge needle. The effectiveness was assessed in terms of relieving pain and good functional outcomes; and rotator cuff tear was clinically assessed among impingement positive patient. The pain was assessed using visual analogue score before and after the administration of the injection. Demographic variables for frequencies and their associations were analysed using SPSS version 20.0. Significance level was p<0.05. Among the 101 cases, there was no case of tear of rotator cuff tendon on clinical assessment. Majority of the patients (58.4%) were females with mean age of 31.38 +-1.13 years. Majority 57 (56.4%) of the patients had acromion type II (curved), which was the most common cause of shoulder impingement. Most had moderate pain. Thirty-four patients required intralesional steroid, which relieved the pain in 31 of them. Conclusion: Shoulder impingement syndrome without tear of rotator cuff tendon was found in younger age group between 40 to 45 years, which was relieved by intralesional corticosteroid administration. These patients had type II (curved) acromion, according to Bigliani classification. (author)

  16. MR imaging in the diagnosis of impingement syndrome

    International Nuclear Information System (INIS)

    Seeger, L.L.; Gold, R.H.; Bassett, L.W.; Ellman, H.

    1986-01-01

    The impingement syndrome is entrapment of the supraspinatus tendon by either the acromion, or a subacromial or acromioclavicular spur. Arthrography is normal during stages I (tendon inflammation) and II (fibrosis). The lack of objective findings often delays diagnosis until stage III (ischemic rotator cuff tear) is present. The purpose was to determine if MR imaging is useful in diagnosing this condition. T1-weighted surface coil scans were obtained on eight patients using a 0.3-T MR system. An axial scout allowed oblique alignment for imaging the osseous-soft tissue relationship and the supraspinatus tendon. MR is capable of displaying the specific pathologic anatomy of this disorder. Impinging spurs can be seen, and the adjacent tendon shows inferior displacement and abnormal signal intensity

  17. Fluorescence Imaging Study of Impinging Underexpanded Jets

    Science.gov (United States)

    Inman, Jennifer A.; Danehy, Paul M.; Nowak, Robert J.; Alderfer, David W.

    2008-01-01

    An experiment was designed to create a simplified simulation of the flow through a hole in the surface of a hypersonic aerospace vehicle and the subsequent impingement of the flow on internal structures. In addition to planar laser-induced fluorescence (PLIF) flow visualization, pressure measurements were recorded on the surface of an impingement target. The PLIF images themselves provide quantitative spatial information about structure of the impinging jets. The images also help in the interpretation of impingement surface pressure profiles by highlighting the flow structures corresponding to distinctive features of these pressure profiles. The shape of the pressure distribution along the impingement surface was found to be double-peaked in cases with a sufficiently high jet-exit-to-ambient pressure ratio so as to have a Mach disk, as well as in cases where a flow feature called a recirculation bubble formed at the impingement surface. The formation of a recirculation bubble was in turn found to depend very sensitively upon the jet-exit-to-ambient pressure ratio. The pressure measured at the surface was typically less than half the nozzle plenum pressure at low jet pressure ratios and decreased with increasing jet pressure ratios. Angled impingement cases showed that impingement at a 60deg angle resulted in up to a factor of three increase in maximum pressure at the plate compared to normal incidence.

  18. Cam versus pincer femoroacetabular impingement. Which type is associated with more hip structural damage? : An exploratory cross-sectional study

    NARCIS (Netherlands)

    Anbar, Ashraf; Ragab, Yasser; Zeinhom, Fatma; El Shaarawy, Nashwa; Emad, Yasser; Abo-Elyoun, Ihab; Hussein, Hanan; Rasker, Johannes J.

    Background: Femoroacetabular impingement (FAI) occurs as a conflict between the proximal femur and the acetabular rim. The purpose of this study was to evaluate MRI findings and look for correlations with pain intensity and duration in each type of FAI separately in an attempt to identify which type

  19. Mycobacterium avium-intracellulare: a rare cause of subacromial bursitis.

    Science.gov (United States)

    Sinha, Raj; Tuckett, John; Hide, Geoff; Dildey, Petra; Karsandas, Alvin

    2015-01-01

    Septic subacromial bursitis is an uncommon disorder with only a few reported cases in the literature. The most common causative organism is Staphylococcus aureus. We report the case of a 61-year-old female with a septic subacromial bursitis where the causative organism was found to be Mycobacterium avium-intracellulare (MAI). The diagnosis was only made following a biopsy, and we use this case to highlight the importance of recognising the need to consider a biopsy and aspiration in atypical situations.

  20. Perspectives on fish impingement

    International Nuclear Information System (INIS)

    Sharma, R.K.

    1977-01-01

    Data on fish impingement and related parameters are being gathered at a large number of power stations throughout the country at substantial monetary and manpower costs. A national survey of fish impingement at power plants was conducted and much of the information compiled in a standardized format--an effort that we think will aid in planning improvements in the design, siting, and operation of the cooling-water intakes. This paper examines the objectives of the fish impingement studies, monitoring programs, variables affecting fish impingement, siting and design criteria, state-of-the-art of screening systems, and suggestions for meeting 316(b) requirements. It also discusses where the emphasis should be placed in future fish-impingement related activities

  1. Relation Between Subacromial Bursitis on Ultrasonography and Efficacy of Subacromial Corticosteroid Injection in Rotator Cuff Disease: A Prospective Comparison Study.

    Science.gov (United States)

    Lee, Doo-Hyung; Hong, Ji Yeon; Lee, Michael Young; Kwack, Kyu-Sung; Yoon, Seung-Hyun

    2017-05-01

    To evaluate the correlations between subacromial bursitis (bursal thickening and effusion) on ultrasonography and its response to subacromial corticosteroid injection in patients with rotator cuff disease. Prospective, longitudinal comparison study. University-affiliated tertiary care hospital. Patients with rotator cuff disease (N=69) were classified into 3 groups based on ultrasonographic findings; (1) normative bursa group (group 1, n=23): bursa and effusion thickness 2mm and effusion thickness 2mm. A single subacromial injection with 20mg of triamcinolone acetonide. Visual analog scale (VAS) of shoulder pain, Shoulder Disability Questionnaire (SDQ), angles of active shoulder range of motion (flexion, abduction, external rotation, and internal rotation), and bursa and effusion thickness at pre- and posttreatment at week 8. There were no significant differences between the 3 groups in demographic characteristics pretreatment. Groups 2 and 3 showed a significant difference compared with group 1 in changes on the VAS and abduction; group 3 showed a significant difference compared with group 1 in changes of the SDQ, internal rotation, and external rotation; and all groups showed significant differences when compared with each other (groups 1 and 3, 2 and 3, and 1 and 2) in changes of thickness. A patient with ultrasonographic observation of subacromial bursitis, instead of normative bursa, can expect better outcome with subacromial corticosteroid injection. Therefore, we recommend a careful selection of patients using ultrasonography prior to injection. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

  2. Risk of subacromial shoulder disorder in airport baggage handlers

    DEFF Research Database (Denmark)

    Møller, Sanne Pagh; Brauer, Charlotte; Mikkelsen, Sigurd

    2018-01-01

    age,exposure variables showed close to significant associations with subacromial shoulder disorder.Results could not confirm our hypothesis that combined information on work task duration and shoulder load intensity was stronger associated with subacromial shoulder disorder than seniority.......Musculoskeletal shoulder-load among baggage handlers measured by combining duration and intensity based on biomechanical and epidemiological information may be a stronger predictor of subacromial shoulder disordersthanbaggage handler seniority.In 2012, a cohort of baggage handlers employed...... at Copenhagen Airport in 1990-2012, and a cohort of unskilledotherwise employed men answered a survey.Self-reported information on work tasks during employment in the airport in combination with work task specific biomechanically modelled forces in the shoulder joint was used to estimate shoulder-load. Exposure...

  3. Current concepts in the diagnosis and treatment of shoulder impingement

    Directory of Open Access Journals (Sweden)

    Bijayendra Singh

    2017-01-01

    Full Text Available Subacromial impingement syndrome (SIS is a very common cause of shoulder pain in the young adults. It can cause debilitating pain, dysfunction, and affects the activities of daily living. It represents a spectrum of pathology ranging from bursitis to rotator cuff tendinopathy which can ultimately lead to degenerative tear of the rotator cuff. Various theories and concepts have been described and it is still a matter of debate. However, most published studies suggest that both extrinsic and intrinsic factors have a role in the development of SIS. The management is controversial as both nonoperative and operative treatments have shown to provide good results. This article aims to provide a comprehensive current concepts review of the pathogenesis, etiologies, clinical diagnosis, appropriate use of investigations, and discussion on the management of SIS.

  4. Neuromuscular control of scapula muscles during a voluntary task in subjects with Subacromial Impingement Syndrome

    DEFF Research Database (Denmark)

    Larsen, C M; Søgaard, Karen; Chreiteh, S S

    2013-01-01

    and time to activity onset. In spite of a tendency to higher activity among SIS 0.10-0.30 between-group differences were not significant neither in ratio of muscle activation 0.80-0.98 nor time to activity onset 0.53-0.98. The hypothesized between-group differences in neuromuscular activity of Trapezius...

  5. Inter-examiner reproducibility of clinical tests and criteria to identify subacromial impingement syndrome

    DEFF Research Database (Denmark)

    Vind, Mikkel; Bogh, Søren Bie; Larsen, Camilla Marie

    2011-01-01

    for cases was ≥3, and for controls ≤1 positive test out of four. Cohen's κ statistics were used for calculating agreement. Results In the overall agreement phase, an agreement of 0.90 was obtained, while in the study phase it was 0.98 with a κ of 0.95 for SIS. κ Values for the individual tests varied...... was followed, consisting of a training, an overall agreement and a study phase. To proceed to the study phase, an overall agreement of 0.80 was required. In total 10, 20 and 44 subjects were included in the three phases, respectively. The case prevalence in the study phase was 50%. The inclusion criterion...

  6. Neuromuscular function in patients with Subacromial Impingement Syndrome and clinical assessment of scapular kinematics

    DEFF Research Database (Denmark)

    Larsen, Camilla Marie; Lund, Hans; Juul-Kristensen, Birgit

    study being rated as ‘good’. Few of the assessment methods in the included studies with ‘fair’ or ‘good’ measurement property ratings demonstrated acceptable results for reliability and validity. Responsiveness was not investigated. CONCLUSION: 1) No between-group differences of SIS and No-SIS subjects...... patient sample with SIS, and to assess the clinimetric properties of clinical assessment methods of scapular kinematics as important aspects for optimising effect measures of treatment in order to improve clinical guidelines in this area. METHODS: Scapular muscle activity was examined, 1) during...... a voluntary arm movement task and 2) selective activation tasks during sessions with and without on-line biofeedback, in a general population consisting of 16 SIS patients and 15 controls (No-SIS). Furthermore, 3) a systematic review was conducted of all available clinical scapular assessment methods...

  7. Neuromuscular function in patients with Subacromial Impingement Syndrome and clinical assessment of scapular kinematics

    DEFF Research Database (Denmark)

    Larsen, Camilla Marie

    muskeldele.I det andet studie blev evnen til selektiv aktivering af de individuelle skapulære muskeldele undersøgt hos 15patienter med SIS under en session med og uden visuel biofeedback, sammenlignet med denne evne hos 15raske kontroller. Med udgangspunkt i præ-definerede kriterier for selektiv aktivering...... kontrolpersonerne opnåede selektiv aktiveringaf individuelle skapulære muskeldele, når de ikke modtog visuel biofeedback af muskelaktiviteten af deenkelte muskeldele.I det tredje studie blev der udarbejdet et systematisk review af alle tilgængelige kliniske målemetoder tilvurdering af skapulas position og bevægelse...... den neuromuskulære aktivitet blandt SIS patienter ograske kontrolpersoner ikke fundet. Derimod viste undersøgelsen af den neuromuskulære funktion med og udenbrug af visuel biofeedback, at uden brug af biofeedback havde kontrolgruppen en bedre kontrol af deskapulære muskler. Dog præsterede SIS...

  8. Subacromial bursitis with rice bodies : a case report

    International Nuclear Information System (INIS)

    Kim, Bong Soo; Joo, Kyung Bin; Park, Dong Woo; Lee, Hak Soo; Oh, Jae Cheon; Lee, Yong Joo; Lee, Won Mi

    1998-01-01

    Multiple rice bodies in joints or bursae are rarely encountered in patients with rheumatoid arthritis. We report the radiologic findings of massive subacromial bursitis with innumerable rice bodies on the right shoulder of a 38-year-old man with rheumatoid arthritis. Subacromial bursography showed markedly distended bursa with multiple nodular filling defects. Precontrast CT scanning revealed well-demarcated hypodense lesion without calcification in subacromio-subdeltoid bursa. Multiple rice bodies showed slightly high signal intensity of T1WI and T2WI, and no enhancement after gadolinium injection. (author). 7 refs., 4 figs

  9. Subacromial bursitis with rice bodies : a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Soo; Joo, Kyung Bin; Park, Dong Woo; Lee, Hak Soo; Oh, Jae Cheon; Lee, Yong Joo; Lee, Won Mi [Hanyang Univ., Seoul (Korea, Republic of). Coll. of Medicine

    1998-04-01

    Multiple rice bodies in joints or bursae are rarely encountered in patients with rheumatoid arthritis. We report the radiologic findings of massive subacromial bursitis with innumerable rice bodies on the right shoulder of a 38-year-old man with rheumatoid arthritis. Subacromial bursography showed markedly distended bursa with multiple nodular filling defects. Precontrast CT scanning revealed well-demarcated hypodense lesion without calcification in subacromio-subdeltoid bursa. Multiple rice bodies showed slightly high signal intensity of T1WI and T2WI, and no enhancement after gadolinium injection. (author). 7 refs., 4 figs.

  10. Subacromial bursitis with rice bodies. Finding in magnetic resonance

    International Nuclear Information System (INIS)

    Miguel Campos, E. de; Hernandez Moreno, L.; Lafuente Martinez, J.; Godoy Lopez, M.A.; Ruiz Noguero, P.

    1994-01-01

    We present a case of subacromial bursitis associated with intraarticular loose bodies, constituted by accumulations of fibrin referred to as rice bodies, in a woman with seronegative rheumatoid arthritis. We demonstrate the clinical and imaging features of this disorder, especially stressing the magnetic resonance (MR) findings. The literature is reviewed. (Author) 14 refs

  11. Subdeltoid/subacromial bursitis associated with influenza vaccination.

    Science.gov (United States)

    Cook, Ian F

    2014-01-01

    A 76-year-old male presented with subacromial/subdeltoid bursitis following influenza vaccine administration into the left deltoid muscle. This shoulder injury related to vaccine administration (SIRVA) could have been prevented by the use of a safe, evidence based protocol for the intramuscular injection of the deltoid muscle.

  12. Arthroscopic treatment of bony loose bodies in the subacromial space

    Directory of Open Access Journals (Sweden)

    Wei Li

    2015-01-01

    Conclusion: The mechanism of formation of bony loose bodies is not clear, may be associated with synovial cartilage metaplasia. Arthroscopic removal of loose bodies and bursa debridement is a good option for treatment of the loose body in the subacromial space, which can receive good function.

  13. Does Subacromial Osteolysis Affect Shoulder Function after Clavicle Hook Plating?

    Directory of Open Access Journals (Sweden)

    Siwei Sun

    2016-01-01

    Full Text Available Purpose. To evaluate whether subacromial osteolysis, one of the major complications of the clavicle hook plate procedure, affects shoulder function. Methods. We had performed a retrospective study of 72 patients diagnosed with a Neer II lateral clavicle fracture or Degree-III acromioclavicular joint dislocation in our hospital from July 2012 to December 2013. All these patients had undergone surgery with clavicle hook plate and were divided into two groups based on the occurrence of subacromial osteolysis. By using the Constant-Murley at the first follow-up visit after plates removal, we evaluated patients’ shoulder function to judge if it has been affected by subacromial osteolysis. Results. We have analyzed clinical data for these 72 patients, which shows that there is no significant difference between group A (39 patients and group B (33 patients in age, gender, injury types or side, and shoulder function (the Constant-Murley scores are 93.38±3.56 versus 94.24±3.60, P>0.05. Conclusion. The occurrence of subacromial osteolysis is not rare, and also it does not significantly affect shoulder function.

  14. Femoroacetabular impingement surgery

    DEFF Research Database (Denmark)

    Reiman, Michael P; Thorborg, Kristian

    2015-01-01

    both the examination and treatment of FAI does not appear to accommodate this exponential growth. In fact, the direction currently taken for FAI is similar to previously described paths of other orthopaedic and sports medicine pathologies (eg, shoulder impingement, knee meniscus tear) for which we have......Femoroacetabuler impingement (FAI) is becoming increasingly recognised as a potential pathological entity for individuals with hip pain. Surgery described to correct FAI has risen exponentially in the past 10 years with the use of hip arthroscopy. Unfortunately, the strength of evidence supporting...

  15. Direct Flame Impingement

    Energy Technology Data Exchange (ETDEWEB)

    None

    2005-09-01

    During the DFI process, high velocity flame jets impinge upon the material being heated, creating a high heat transfer rate. As a result, refractory walls and exhaust gases are cooler, which increases thermal efficiency and lowers NOx emissions. Because the jet nozzles are located a few inches from the load, furnace size can be reduced significantly.

  16. Subacromial bursitis following human papilloma virus vaccine misinjection.

    Science.gov (United States)

    Uchida, Soshi; Sakai, Akinori; Nakamura, Toshitaka

    2012-12-17

    A patient presented at our clinic with severe subacromial bursitis, which persisted for several months following a third booster injection with Cervarix™. Chronic subacromial bursitis manifested itself in this patient after what appeared to be the misinjection of vaccine in close proximity to the acromion. This bursitis was resistant to conventional physiotherapy and to corticosteroid therapy, but was responsive to arthroscopic surgery. Since such patients may present to an arthroscopic surgeon only months after receiving a vaccine injection, this etiological link may not be fully appreciated by treating clinicians. Further, the accuracy of injection in the deltoid region also appears under appreciated, and this report highlights the importance of accurate injection to the deltoid region or in certain cases, the value of simply changing the injection site to another larger muscle. Copyright © 2012 Elsevier Ltd. All rights reserved.

  17. Scapula kinematics of pull-up techniques: Avoiding impingement risk with training changes.

    Science.gov (United States)

    Prinold, Joe A I; Bull, Anthony M J

    2016-08-01

    Overhead athletic activities and scapula dyskinesia are linked with shoulder pathology; pull-ups are a common training method for some overhead sports. Different pull-up techniques exist: anecdotally some are easier to perform, and others linked to greater incidences of pathology. This study aims to quantify scapular kinematics and external forces for three pull-up techniques, thus discussing potential injury implications. An observational study was performed with eleven participants (age=26.8±2.4 years) who regularly perform pull-ups. The upward motions of three pull-up techniques were analysed: palms facing anterior, palms facing posterior and wide-grip. A skin-fixed scapula tracking technique with attached retro-reflective markers was used. High intra-participant repeatability was observed: mean coefficients of multiple correlations of 0.87-1.00 in humerothoracic rotations and 0.77-0.90 for scapulothoracic rotations. Standard deviations of hand force was low: kinematics were observed between the pull-up techniques. The reverse technique has extreme glenohumeral internal-external rotation and large deviation from the scapula plane. The wide technique has a reduced range of pro/retraction in the same HT plane of elevation and 90° of arm abduction with 45° external rotation was observed. All these factors suggest increased sub-acromial impingement risk. The scapula tracking technique showed high repeatability. High arm elevation during pull-ups reduces sub-acromial space and increases pressure, increasing the risk of impingement injury. Wide and reverse pull-ups demonstrate kinematics patterns linked with increased impingement risk. Weight-assisted front pull-ups require further investigation and could be recommended for weaker participants. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  18. All-theoretical prediction of cabin noise due to impingement of propeller vortices on a wing structure

    Science.gov (United States)

    Martinez, R.; Cole, J. E., III; Martini, K.; Westagard, A.

    1987-01-01

    Reported calculations of structure-borne cabin noise for a small twin engine aircraft powered by tractor propellers rely on the following three-stage methodological breakup of the problem: (1) the unsteady-aerodynamic prediction of wing lift harmonics caused by the whipping action of the vortex system trailed from each propeller; (2) the associated wing/fuselage structural response; (3) the cabin noise field for the computed wall vibration. The first part--the estimate of airloads--skirts a full-fledged aeroelastic situation by assuming the wing to be fixed in space while cancelling the downwash field of the cutting vortices. The model is based on an approximate high-frequency lifting-surface theory justified by the blade rate and flight Mach number of application. Its results drive a finite-element representation of the wing accounting for upper and lower skin surfaces, spars, ribs, and the presence of fuel. The fuselage, modeled as a frame-stiffened cylindrical shell, is bolted to the wing.

  19. Active Control of Supersonic Impinging Jets Using Supersonic Microjets

    National Research Council Canada - National Science Library

    Alvi, Farrukh

    2005-01-01

    .... Supersonic impinging jets occur in many applications including in STOVL aircraft where they lead to a highly oscillatory flow with very high unsteady loads on the nearby aircraft structures and the landing surfaces...

  20. Properties of Supersonic Impinging Jets

    Science.gov (United States)

    Alvi, F. S.; Iyer, K. G.; Ladd, J.

    1999-11-01

    A detailed study examining the behavior of axisymmetric supersonic jets impinging on a ground plane is described. Our objective is to better understand the aeroacoustics governing this complex flowfield which commonly occurs in the vicinity of STOVL aircraft. Flow issuing through a Mach 1.5 C-D and a converging sonic nozzle is examined over a wide parametric range. For some cases a large diameter circular 'lift' plate, with an annular hole through which the jet is issued, is attached at the nozzle exit to simulate a generic airframe. The impinging jet flowfield was examined using Particle Image Velocimetry (PIV), which provides the velocity field for the entire region and shadowgraph visualization techniques. Near-field acoustic, as well as, mean and unsteady pressure measurements on the ground and lift plate surfaces were also obtained. The velocity field data, together with the surface flow measurements have resulted in a much better understanding of this flow from a fundamental standpoint while also identifying critical regions of interest for practical applications. Some of these findings include the presence of a stagnation bubble with recirculating flow; a very high speed (transonic/supersonic) radial wall jet; presence of large, spatially coherent turbulent structures in the primary jet and wall jet and high unsteady loads on the ground plane and lift plates. The results of a companion CFD investigation and its comparison to the experimental data will also be presented. Very good agreement has been found between the computational and experimental results thus providing confidence in the development of computational tools for the study of such flows.

  1. Is ultrasound-guided injection more effective in chronic subacromial bursitis?

    Science.gov (United States)

    Hsieh, Lin-Fen; Hsu, Wei-Chun; Lin, Yi-Jia; Wu, Shih-Hui; Chang, Kae-Chwen; Chang, Hsiao-Lan

    2013-12-01

    Although ultrasound (US)-guided subacromial injection has shown increased accuracy in needle placement, whether US-guided injection produces better clinical outcome is still controversial. Therefore, this study aimed to compare the efficacy of subacromial corticosteroid injection under US guidance with palpation-guided subacromial injection in patients with chronic subacromial bursitis. Patients with chronic subacromial bursitis were randomized to a US-guided injection group and a palpation-guided injection group. The subjects in each group were injected with a mixture of 0.5 mL dexamethasone suspension and 3 mL lidocaine into the subacromial bursa. The primary outcome measures were the visual analog scale for pain and active and passive ranges of motion of the affected shoulder. Secondary outcome measures were the Shoulder Pain and Disability Index, the Shoulder Disability Questionnaire, and the 36-item Short-Form Health Survey (SF-36). The primary outcome measures were evaluated before, immediately, 1 wk, and 1 month after the injection; the secondary outcome measures were evaluated before, 1 wk, and 1 month after the injection. Of the 145 subjects screened, 46 in each group completed the study. Significantly greater improvement in passive shoulder abduction and in physical functioning and vitality scores on the SF-36 were observed in the US-guided group. The pre- and postinjection within-group comparison revealed significant improvement in the visual analog scale for pain and range of motion, as well as in the Shoulder Pain and Disability Index, Shoulder Disability Questionnaire, and SF-36 scores, in both groups. The US-guided subacromial injection technique produced significantly greater improvements in passive shoulder abduction and in some items of the SF-36. US is effective in guiding the needle into the subacromial bursa in patients with chronic subacromial bursitis.

  2. Radiological diagnosis of femoroacetabular impingement

    International Nuclear Information System (INIS)

    Mamisch, T.C.; Werlen, S.; Trattnig, S.; Zilkens, C.; Kim, Y.J.; Siebenrock, K.A.; Bittersohl, B.

    2009-01-01

    Femoroacetabular impingements (FAI) are due to an anatomical disproportion between the proximal femur and the acetabulum which causes premature wear of the joint surfaces. An operation is often necessary in order to relieve symptoms such as limited movement and pain as well as to prevent or slow down the degenerative process. The result is dependent on the preoperative status of the joint with poor results for advanced arthritis of the hip joint. This explains the necessity for an accurate diagnosis in order to recognize early stages of damage to the joint. The diagnosis of FAI includes clinical examination, X-ray examination and magnetic resonance imaging (MRI). The standard X-radiological examination for FAI is carried out using two X-ray images, an anterior-posterior view of the pelvis and a lateral view of the proximal femur, such as the cross-table lateral or Lauenstein projections. It is necessary that positioning criteria are adhered to in order to avoid distortion artifacts. MRI permits an examination of the pelvis on three levels and should also include radial planned sequences for improved representation of peripheral structures, such as the labrum and peripheral cartilage. The use of contrast medium for a direct MR arthrogram has proved to be advantageous particularly for representation of labrum damage. The data with respect to cartilage imaging are still unclear. Further developments in technology, such as biochemical-sensitive MRI applications, will be able to improve the diagnosis of the pelvis in the near future. (orig.) [de

  3. Subacromial triamcinolone acetonide, hyaluronic acid and saline injections for shoulder pain an RCT investigating the effectiveness in the first days.

    Science.gov (United States)

    Penning, Ludo I F; de Bie, Rob A; Walenkamp, Geert H I M

    2014-10-23

    Subacromial impingement is a common cause of shoulder complaints in general practice. When the initial treatment with acetaminophen and low dose Non Steroidal Anti Inflammatory Drugs fails, triamcinolone acetonide injections are commonly used. Triamcinolone acetonide injections are effective at four to six weeks. Little is known about the pain relief effect of triamcinolone acetonide injections in the first days after injection and the effect of repeated injection. In this study we investigate the effect of triamcinolone acetonide injections compared to hyaluronic acid and NaCl injections using a pain diary. 159 Patients recruited for an RCT comparing the effect of subacromial injections of triamcinolone acetonide, hyaluronic acid and sodium chloride (NaCl) were used in this study. They were blinded for their treatment and could receive up to three injections. Primary outcome consisted of the patient perceived pain on a VAS score recorded on a daily basis during 21 days following injection. Secondary outcome consisted of the amount of taken escape medication following injection and adverse effects. All patients received the first injection. 150 patients also received the second and third injections. 97% Of the paper and pencil pain diaries were returned for data analysis.The triamcinolone acetonide group showed the largest decrease in pain on the VAS scores after injection compared to the hyaluronic acid and NaCl group in the first week after injection. The reduction in pain was best achieved after the first injection, the second triamcinolone acetonide injection showed a further reduction in pain. The third triamcinolone acetonide injection only showed a slight improvement in pain reduction. In this study we could show a booster effect in pain reduction after repeated triamcinolone acetonide injection. The triamcinolone acetonide group showed a faster reduction in pain after injection compared to the hyaluronic acid and NaCl group. The effect was best seen after

  4. SHORT-TERM EFFECTS OF INSTRUMENT-ASSISTED SOFT TISSUE MOBILIZATION ON PAIN FREE RANGE OF MOTION IN A WEIGHTLIFTER WITH SUBACROMIAL PAIN SYNDROME.

    Science.gov (United States)

    Coviello, Joseph Paul; Kakar, Rumit Singh; Reynolds, Timothy James

    2017-02-01

    While there is limited evidence supporting the use of soft tissue mobilization techniques for Subacromial Pain Syndrome (SAPS), synonymous with subacromial impingement syndrome, previous studies have reported successful outcomes using soft tissue mobilization as a treatment technique. The purpose of this case report is to document the results of Instrument-Assisted Soft Tissue Mobilization (IASTM) for the treatment of SAPS. Diagnosis was reached based on the subject's history, tenderness to palpation, and four out of five positive tests in the diagnostic cluster. Treatment consisted of three visits where the IASTM technique was applied to the pectoral muscles as well as periscapular musculature followed by retesting pain-free shoulder flexion active range of motion (AROM) and Numerical Pain Rating Scale (NPRS) during active shoulder flexion. Scapulothoracic mobilization and stretching were performed after AROM measurement. The subject reported an NPRS of 0/10 and demonstrated improvements in pain free flexion AROM in each of the three treatment sessions post-IASTM: 85 ° to 181 °, 110 ° to 171 °, and 163 ° to 174 ° with some carryover in pain reduction and pain free AROM to the next treatment. Through three treatments, DASH score improved by 17.34%, Penn Shoulder Score improved 29%, worst NPRS decreased from 4/10 to 0/10, and a GROC score of 6. IASTM may have a beneficial acute effect on pain free shoulder flexion. In conjunction with scapulothoracic mobilizations and stretching, IASTM may improve function, decrease pain, and improve patient satisfaction. While this technique will not ameliorate the underlying pathomechanics contributing to SAPS, it may serve as a valuable tool to restore ROM and decrease pain allowing the patient to reap the full benefits of a multi-modal treatment approach. 5.

  5. Four-jet impingement: Noise characteristics and simplified acoustic model

    International Nuclear Information System (INIS)

    Brehm, C.; Housman, J.A.; Kiris, C.C.; Barad, M.F.; Hutcheson, F.V.

    2017-01-01

    Highlights: • Large eddy simulation of unique four jet impingement configuration. • Characterization of flow features using POD, FFT, and wavelet decomposition. • Noise source identification utilizing causality method. • Development of simplified acoustic model utilizing equivalent source method. • Comparison with experimental data from BENS experiment. - Abstract: The noise generation mechanisms for four directly impinging supersonic jets are investigated employing implicit large eddy simulations with a higher-order weighted essentially non-oscillatory scheme. Although these types of impinging jet configurations have been used in many experiments, a detailed investigation of the noise generation mechanisms has not been conducted before. The flow field is highly complex and contains a wide range of temporal and spatial scales relevant for noise generation. Proper orthogonal decomposition is utilized to characterize the unsteady nature of the flow field involving unsteady shock oscillations, large coherent turbulent flow structures, and the sporadic appearance of vortical flow structures in the center of the four-jet impingement region. The causality method based on Lighthills acoustic analogy is applied to link fluctuations of flow quantities inside the source region to the acoustic pressure in the far field. It will be demonstrated that the entropy fluctuation term plays a vital role in the noise generation process. Consequently, the understanding of the noise generation mechanisms is employed to develop a simplified acoustic model of the four-jet impingement device by utilizing the equivalent source method. Finally, three linear acoustic four-jet impingement models of the four-jet impingement device are used as broadband noise sources inside an engine nacelle and the acoustic scattering results are validated against far-field acoustic experimental data.

  6. Impinging jets - a short review on strategies for heat transfer enhancement

    Science.gov (United States)

    Nastase, Ilinca; Bode, Florin

    2018-02-01

    In industrial applications, heat and mass transfer can be considerably increased using impinging jets. A large number of flow phenomena will be generated by the impinging flow, such as: large scale structures, large curvature involving strong shear and normal stresses, stagnation in the wall boundary layers, heat transfer with the impinged wall, small scale turbulent mixing. All these phenomena are highly unsteady and even if nowadays a substantial number of studies in the literature are dedicated, the impinging jets are still not fully understood due to the highly unsteady nature and more over due to great difficulty of performing detailed numerical and experimental investigations.

  7. Subacromial bursitis with giant rice bodies as initial presentation of rheumatoid arthritis.

    Science.gov (United States)

    Subramaniam, Ramesh; Tan, Justina Wei Lyn; Chau, Cora Yuk Ping; Lee, Keng Thiam

    2012-10-01

    Rice body formation is a nonspecific response to chronic synovial inflammation associated with tuberculous arthritis, rheumatoid arthritis, juvenile rheumatoid arthritis, seronegative inflammatory arthritis, and even osteoarthritis. Such bodies were termed rice bodies because of their close resemblance to grains of polished white rice. We present a case report of a middle-aged woman with right shoulder subacromial/subdeltoid bursitis with giant rice body formation as her initial presentation of rheumatoid arthritis. Her right shoulder symptoms resolved after subacromial and subdeltoid bursectomy and removal of the rice bodies. She subsequently developed inflammatory arthritis of other joints, met the criteria for rheumatoid arthritis, and has been treated medically.

  8. Dynamic enhanced MRI of the subacromial bursa: correlation with arthroscopic and histological findings

    International Nuclear Information System (INIS)

    Matsuzaki, S.; Yoneda, M.; Kobayashi, Y.; Fukushima, S.; Wakitani, S.

    2003-01-01

    Objective: To assess dynamic MRI with Gd-DTPA enhancement for evaluating inflammatory changes in the subacromial bursa. Design and patients: We detected the signal intensity changes in dynamic MRI of the subacromial bursa, and confirmed these macroscopically by arthroscopy and histologically. The signal intensity was measured using built-in software, and the enhancement ratio (E ratio) was calculated from dynamic MR images. In addition, as a parameter of the rate of the increase in the signal intensity from 0 to 80 s, the mean increase per second in the E ratio was obtained as the coefficient of enhancement (CE). The correlation was studied of the E ratio and CE with the arthroscopic findings (redness, villous formation, thickening and adhesion), and of the E ratio and CE with the histological findings (capillary proliferation, papillary hyperplasia, fibrosis and inflammatory cell infiltration) of the subacromial bursa. Of patients with shoulder pain, this study included those with rotator cuff injury; patients with rheumatoid arthritis or pitching shoulder disorders were excluded. There were 27 patients (15 men, 12 women) ranging in age from 25 to 73 years (mean 49.1 years). Dynamic MRI of the shoulder was also performed on the healthy side of 10 patients and in five normal young volunteers. Results and conclusions: Changes in signal intensity on dynamic MRI were measured in the subacromial bursa. The E ratio (80 s) and CE (0-80 s) were significantly correlated with redness and villous formation as arthroscopic findings, positively correlated with capillary proliferation and papillary hyperplasia as histological findings (p < 0.05), and negatively correlated with fibrosis as a histological finding (p < 0.05) in the subacromial bursa. The patterns of dynamic curves were well correlated with the bursoscopic and histological findings of the synovium of the subacromial bursa. Dynamic MRI appears to correlate with inflammatory activity of synovium of the subacromial

  9. Rotational effects on impingement cooling

    Science.gov (United States)

    Epstein, A. H.; Kerrebrock, J. L.; Koo, J. J.; Preiser, U. Z.

    1987-01-01

    The present consideration of rotation effects on heat transfer in a radially exhausted, impingement-cooled turbine blade model gives attention to experimental results for Reynolds and Rossby numbers and blade/coolant temperature ratio values that are representative of small gas turbine engines. On the basis of a model that encompasses the effects of Coriolis force and buoyancy on heat transfer, bouyancy is identified as the cause of an average Nusselt number that is 20-30 percent lower than expected from previous nonrotating data. A heuristic model is proposed which predicts that the impingement jets nearest the blade roots should deflect inward, due to a centripetal force generated by their tangential velocity counter to the blade motion. Potentially serious thermal stresses must be anticipated from rotation effects in the course of blade design.

  10. [Athletic pubalgia and hip impingement].

    Science.gov (United States)

    Berthaudin, A; Schindler, M; Ziltener, J-L; Menetrey, J

    2014-07-16

    Athletic pubalgia is a painful and complex syndrom encountered by athletes involved in pivoting and cutting sports such as hockey and soccer. To date, there is no real consensus on the criteria for a reliable diagnostic, the different investigations, and the appropriate therapy. Current literature underlines intrinsic and extrinsic factors contributing to athletic pubalgia. This review article reports upon two novelties related to the issue: the importance and efficience of prevention program and the association of femoro-acetabular impingement with the pubalgia.

  11. Clinical radiation diagnostics of shoulder joint impingement syndrome

    International Nuclear Information System (INIS)

    Litvin, Yu.P.; Logvinenko, V.V.

    2014-01-01

    46 patients about an impingement are investigated by a syndrome of a humeral joint. Among them men was 28 (60,9 %) the person, women 18 (39,1 %). Middle age of the surveyed has made 52,6 ± 2,0 year. The traditional roentgenography is executed to all patients, a spiral computer tomography - 5 (10,9 %), an ultrasonography - 44 (95,7 %), a magnetic resonance imaging - 11 (23,9 %). Operative treatment is spent 16 (34,8 %) by the patient. Direct radial symptoms are what specify an impingement of a syndrome of a humeral joint in the reasons, indirect - symptoms of an inflammation both degenerate and dystrophic changes of structures of area of a humeral joint which are involved in pathological process. The best results are given by complex radial research at which it is possible to find out direct and indirect symptoms a syndrome impingement

  12. Analysis of factors influencing the impingement of threadfin shad (Dorosoma pretenense) at power plants in the southeastern United States

    International Nuclear Information System (INIS)

    Loar, J.M.; Griffith, J.S.; Kumar, K.D.

    1977-01-01

    Data on intake design and location, plant operating procedures, water quality, numbers of fish impinged, and sampling procedures were analyzed for 27 fossil-fueled and 5 nuclear power plants located on inland waters in the southeastern United States. Small (less than 9 cm) clupeids, especially threadfin shad (Dorosoma pretenense), comprised the majority of the fish impinged at these facilities. The parameter that was most strongly associated with shad impingement was water temperature. Maximum impingement rates occurred during the winter when intake temperatures dropped below 10 0 C. Analyses of differences in impingement rates between plants failed to adequately demonstrate that the magnitude of impingement at a particular plant was the result of any site-specific characteristics associated with intake design or location. High approach velocities at the traveling screens did not necessarily result in high levels of impingement. Results obtained from inter-unit comparisons at several plants indicate that unit and screen differences do exist, but it is unclear from existing data whether or not such inter-unit differences determine the magnitude of impingement losses or merely affect the distribution of impinged fish at a given intake structure. Recommendations for monitoring fish impingement include the identification of impinged fish by species, collection of data on water temperatures and various plant operational parameters, periodic analyses of localized velocity regimes near the intake, and frequent estimates of the relative density of the fish population in the vicinity of the intake

  13. Impingement studies at the 100-N reactor water intake

    International Nuclear Information System (INIS)

    Page, T.L.; Neitzel, D.A.; Gray, R.H.

    1977-09-01

    Fish impingement and traveling screen passage were studied at the 100-N reactor water intake structure, Columbia River mile 380, from late April to August 1977. Species and numbers of fish affected were determined and compared to those at the adjacent Hanford Generating Project (HGP). Fish protection procedures previously developed for HGP were evaluated for application at 100-N

  14. Flow Characteristics of Rectangular Underexpanded Impinging Jets

    Institute of Scientific and Technical Information of China (English)

    Minoru YAGA; Yoshio KINJO; Masumi TAMASHIRO; Kenyu OYAKAWA

    2006-01-01

    In this paper, the flow fields of underexpanded impinging jet issued from rectangular nozzles of aspect ratio 1,3 and 5 are numerically and experimentally studied. Two dimensional temperature and pressure distributions are measured by using infrared camera and the combination of a pressure scanning device and a stepping motor, respectively. The variation of the stagnation pressure on the impinging plate reveals that a hystcretic phenomenon exists during the increasing and decreasing of the pressure ratio for the aspect ratio of 3.0 and 5.0. It is also found that the nozzle of aspect ratio 1.0 caused the largest total pressure loss pc/p0 = 0.27 at the pressure ratio of p0/pb, = 6.5, where pc is the stagnation center pressure on the wall, p0 the upstream stagnation pressure, pb the ambient pressure. The other two nozzles showed that the pressure loss pc / p0=0.52 and 0.55 were achieved by the nozzles of the aspect ratio 3,0 and 5.0, respectively. The comparison between the calculations and experiments is fairly good, showing the three dimensional streamlines and structures of the shock waves in the jets. However, the hysteresis of the pressure variations observed in the experiments between the pressure ratio of 3.5 and 4.5 cannot be confirmed in the calculations.

  15. Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance

    International Nuclear Information System (INIS)

    Law, T.C.; Chong, S.F.; Lu, P.P.; Mak, K.H.

    1998-01-01

    The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd

  16. Bilateral subacromial bursitis with macroscopic rice bodies: Ultrasound, CT and MR appearance

    Energy Technology Data Exchange (ETDEWEB)

    Law, T.C.; Chong, S.F.; Lu, P.P. [Kwong Wah Hospital (Hong Kong). Department of Radiology; Mak, K.H. [Kwong Wah Hospital (Hong Kong). Department of Orthopaedics and Traumatology

    1998-05-01

    The radiological findings of ultrasound, CT and MR of a case of bilateral subacromial bursitis with macroscopic rice bodies is described. MRI is the investigation of choice and the intravenous gadolinium-enhanced usefulness was noted. The previous literature is also reviewed. Copyright (1998) Blackwell Science Pty Ltd 5 refs., 1 tab., 4 figs.

  17. Exogenous application of platelet-leukocyte gel during open subacromial decompression contributes to improved patient outcome

    NARCIS (Netherlands)

    Everts, P. A.; Devilee, R. J. J.; Mahoney, C. Brown; van Erp, A.; Oosterbos, C. J. M.; Stellenboom, M.; Knape, J. T. A.; van Zundert, A.

    2008-01-01

    Background: Platelet-leukocyte gel (PLG) is being used during various surgical procedures in an attempt to enhance the healing process. We studied the effects of PLG on postoperative recovery of patients undergoing open subacromial decompression (OSD). Methods: PLG was produced from

  18. Fish impingement at Lake Michigan power plants

    International Nuclear Information System (INIS)

    Sharma, R.K.; Freeman, R.F.; Spigarelli, S.A.

    1976-01-01

    A study was initiated in 1974 to survey the magnitude and to evaluate the impact of fish impingement at 20 power plants on the Great Lakes. Data on impingement rates, site characteristics, intake designs and operational features have been collected and analyzed. Interpretive analyses of these data are in progress. The objectives of this study were: to summarize fish impingement data for Lake Michigan (16/20 plants surveyed are on Lake Michigan); to assess the significance of total and source-related mortalities on populations of forage and predator species; and to expand the assessment of power plant impingement to include all water intakes on Lake Michigan. Data are tabulated

  19. Diagnostic imaging of shoulder impingement

    International Nuclear Information System (INIS)

    Merl, T.; Weinhardt, H.; Oettl, G.; Lenz, M.; Riel, K.A.

    1996-01-01

    Magnetic resonance imaging is a method that has been advancing in the last few years to the modality of choice for diagnostic evaluation of the bone joints, as the method is capable of imaging not only the ossous but also the soft tissue components of the joint. MRI likewise has become an accepted method for diagnostic evaluation of syndromes of the shoulder, with high diagnostic accuracy in detecting rotator cuff lesions, or as an efficient MRI arthrography for evaluation of the instability or lesions of the labrocapsular complex. In the evaluation of early stages of shoulder impingement, the conventional MRI technique as a static technique yields indirect signs which in many cases do not provide the diagnostic certainty required in order to do justice to the functional nature of the syndrome. In these cases, functional MRI for imaging of the arm in abducted position and in rotational movement may offer a chance to early detect impingement and thus identify patients who will profit from treatment at an early stage [de

  20. Flowfield Behavior of Supersonic Impinging Jets

    Science.gov (United States)

    Iyer, K. G.; Alvi, F. S.

    1998-11-01

    A detailed study is being conducted which examines the behavior of normally impinging, supersonic jets, issuing from axisymmetric a Mach 1.5 C-D and a sonic nozzle. Our goal is to understand the physics of this flowfield (commonly observed in STOVL aircraft) and its influence on the acoustic and aerodynamic loading on the ground plane and the airframe. The airframe is simulated by a circular disc ('lift' plate) with an annular hole from which the jet is issued. Tests are carried out for a wide range of pressure ratios and the ground plane distance is varied from 1.5 to 60 nozzle diameters. Flowfield measurements include Particle Image Velocimetry (PIV) and schlieren/shadowgraph visualization. Surface measurements on the ground and lift plates include mean and unsteady surface pressure distributions and the surface streamline visualization. Near-field acoustic measurements using a microphone are also obtained. For certain cases, the PIV measurements -- first of their kind, to our knowledge -- clearly show the presence of large-scale coherent turbulent structures which, upon jet impingement, propagate into the resulting wall jet. These structures are believed to generate very high unsteady pressure loads on the ground plane thus leading to ground erosion. They are also suspected to be the source of acoustic waves which lead to a feedback loop causing violent oscillations of the primary jet and can result in increased acoustic loading and subsequent damage to the aircraft. As a result of this detailed study over a wide parametric space, we hope to gain a much better understanding of the physical mechanisms governing this complex flow.

  1. Impingement jet cooling in gas turbines

    CERN Document Server

    Amano, R S

    2014-01-01

    Due to the requirement for enhanced cooling technologies on modern gas turbine engines, advanced research and development has had to take place in field of thermal engineering. Impingement jet cooling is one of the most effective in terms of cooling, manufacturability and cost. This is the first to book to focus on impingement cooling alone.

  2. Fish impingement at Montecello Nuclear Plant

    International Nuclear Information System (INIS)

    Grotbeck, L.M.; Bechthold, J.L.

    1975-01-01

    To properly evaluate total impact of power generation facilities on aquatic systems, it is necessary to perform site specific fish impingement studies. Intake and screen approach velocities should not be averaged when considering potential screen impingement problems because of wide vertical and horizontal variation in velocity which tend to trap fish. It was estimated that 2,952 fish were impinged during 4 months of sampling with 90.9% of these comprised of black bullheads (Ictalurus melas) and black crappies (Pomoxis nigromaculatus). Distinct relationships can be found between number of impinging fish and river flow, percentage river diverted through the plant, water temperature, and the time of year. For the months of June, July, August, and September, approx 55% of all impingement occurs in June

  3. Exercise therapy after ultrasound-guided corticosteroid injections in patients with subacromial pain syndrome

    DEFF Research Database (Denmark)

    Ellegaard, Karen; Christensen, Robin; Rosager, Sara

    2016-01-01

    BACKGROUND: Subacromial pain syndrome (SAPS) accounts for around 50 % of all cases of shoulder pain. The most commonly used treatments are glucocorticosteroid (steroid) injections and exercise therapy; however, despite treatment SAPS patients often experience relapse of their symptoms. Therefore...... the clinical effect of combining steroid and exercise therapy is highly relevant to clarify. The aim of this randomized controlled trial was to investigate if exercise therapy added to steroid injection in patients with SAPS will improve the effect of the injection therapy on shoulder pain. METHODS......: In this two-arm randomized trial running over 26 weeks, patients with unilateral shoulder pain (> 4 weeks) and thickened subacromial bursa (> 2 mm on US) were included. At baseline all participants received two steroid injections into the painful shoulder with an interval of one week. Subsequently they were...

  4. Synovial Chondromatosis of the Subacromial Bursa Causing a Bursal-Sided Rotator Cuff Tear

    Directory of Open Access Journals (Sweden)

    Julie A. Neumann

    2015-01-01

    Full Text Available Synovial chondromatosis is an uncommon condition, and involvement of the shoulder is even more rare. We report on a 39-year-old female who presented with symptoms, radiographic features, and intraoperative findings consistent with multiple subacromial loose bodies resulting in a partial-thickness, bursal-sided rotator cuff tear of the supraspinatus muscle. She was treated with an arthroscopic removal of loose bodies, complete excision of the subacromial/subdeltoid bursa, acromioplasty, and rotator cuff repair. To our knowledge, this is the first report of arthroscopic treatment for a bursal-sided, partial-thickness rotator cuff tear treated with greater than two-year clinical and radiographic follow-up. We utilized shoulder scores, preoperative and postoperative range of motion, and imaging to assess the results of treatment and surveillance for recurrence in our patient after two-year follow-up.

  5. Effect of glenohumeral elevation on subacromial supraspinatus compression risk during simulated reaching.

    Science.gov (United States)

    Lawrence, Rebekah L; Schlangen, Dustin M; Schneider, Katelyn A; Schoenecker, Jonathan; Senger, Andrea L; Starr, William C; Staker, Justin L; Ellermann, Jutta M; Braman, Jonathan P; Ludewig, Paula M

    2017-10-01

    Mechanical subacromial rotator cuff compression is one theoretical mechanism in the pathogenesis of rotator cuff disease. However, the relationship between shoulder kinematics and mechanical subacromial rotator cuff compression across the range of humeral elevation motion is not well understood. The purpose of this study was to investigate the effect of humeral elevation on subacromial compression risk of the supraspinatus during a simulated functional reaching task. Three-dimensional anatomical models were reconstructed from shoulder magnetic resonance images acquired from 20 subjects (10 asymptomatic, 10 symptomatic). Standardized glenohumeral kinematics from a simulated reaching task were imposed on the anatomic models and analyzed at 0, 30, 60, and 90° humerothoracic elevation. Five magnitudes of humeral retroversion were also imposed on the models at each angle of humerothoracic elevation to investigate the impact of retroversion on subacromial proximities. The minimum distance between the coracoacromial arch and supraspinatus tendon and footprint were quantified. When contact occurred, the magnitude of the intersecting volume between the supraspinatus tendon and coracoacromial arch was also quantified. The smallest minimum distance from the coracoacromial arch to the supraspinatus footprint occurred between 30 and 90°, while the smallest minimum distance to the supraspinatus tendon occurred between 0 and 60°. The magnitude of humeral retroversion did not significantly affect minimum distance to the supraspinatus tendon except at 60 or 90° humerothoracic elevation. The results of this study provide support for mechanical rotator cuff compression as a potential mechanism for the development of rotator cuff disease. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2329-2337, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  6. Prevalence of Propionibacterium acnes in the glenohumeral compared with the subacromial space in primary shoulder arthroscopies.

    Science.gov (United States)

    Patzer, Thilo; Petersdorf, Sabine; Krauspe, Ruediger; Verde, Pablo Emilio; Henrich, Birgit; Hufeland, Martin

    2018-05-01

    We hypothesized that the prevalence of Propionibacterium acnes in patients undergoing primary shoulder arthroscopy is equal in the glenohumeral space compared with the subacromial space. Patients aged 18 years or older with shoulder arthroscopies were included. The exclusion criteria were prior shoulder operations, complete rotator cuff tears, systemic inflammatory diseases, tumors, shoulder injections within 6 months of surgery, and antibiotic therapy within 14 days preoperatively. After standardized skin disinfection with Kodan Tinktur Forte Gefärbt, a skin swab was taken at the posterior portal. Arthroscopy was performed without cannulas, prospectively randomized to start either in the glenohumeral space or in the subacromial space, with direct harvesting of a soft-tissue biopsy specimen. Sample cultivation was conducted according to standardized criteria for bone and joint aspirate samples and incubated for 14 days. Matrix-assisted laser desorption-ionization time-of-flight spectrometry was used for specimen identification in positive culture results. The study prospectively included 115 consecutive patients with normal C-reactive protein levels prior to surgery (54.8% men; mean age, 47.2 ± 14.6 years). P acnes was detected on the skin after disinfection in 36.5% of patients, in the glenohumeral space in 18.9%, and in the subacromial space in 3.5% (P = .016). The prevalence of P acnes is significantly higher in the glenohumeral space compared with the subacromial space in primary shoulder arthroscopies. The results do not confirm the contamination theory but also cannot clarify whether P acnes is a commensal or enters the joint hematologically or even lymphatically or via an unknown pathway. Despite standardized surgical skin disinfection, P acnes can be detected in skin swab samples in more than one-third of patients. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  7. Distinguishing multiple rice body formation in chronic subacromial-subdeltoid bursitis from synovial chondromatosis

    International Nuclear Information System (INIS)

    Chen, Albert; Wong, Lun-Yick; Sheu, Chin-Yin; Chen, Be-Fong

    2002-01-01

    Multiple rice body formation is a complication of chronic bursitis. Although it resembles synovial chondromatosis clinically and on imaging, the literature suggests that analysis of radiographic and MR appearances should allow discrimination. We report the imaging findings in a 41-year-old man presenting with rice body formation in chronic subacromial-subdeltoid bursitis. We found that the signal intensity of the rice bodies is helpful in making the diagnosis. (orig.)

  8. Distinguishing multiple rice body formation in chronic subacromial-subdeltoid bursitis from synovial chondromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Albert; Wong, Lun-Yick; Sheu, Chin-Yin [Department of Radiology, Mackay Memorial Hospital, Taipei (Taiwan); Chen, Be-Fong [Department of Pathology, Mackay Memorial Hospital, Taipei (Taiwan)

    2002-02-01

    Multiple rice body formation is a complication of chronic bursitis. Although it resembles synovial chondromatosis clinically and on imaging, the literature suggests that analysis of radiographic and MR appearances should allow discrimination. We report the imaging findings in a 41-year-old man presenting with rice body formation in chronic subacromial-subdeltoid bursitis. We found that the signal intensity of the rice bodies is helpful in making the diagnosis. (orig.)

  9. Noise characteristics and flow field of an impinging jet on a conical obstacle

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xin; Xie, Junlong; Shu, Shuiming; Zhang, Yi, E-mail: hustxjl@163.com [School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, 430074 (China)

    2017-12-15

    The noise characteristics and flow field of a low-speed impinging jet on a conical obstacle have been numerically simulated using the kinetic energy transport subgrid-scale model of the large-eddy simulation method. Noise measurement is carried out to validate the proposed simulation method. The effects of the impinging distance on the development, separation and diffusion of vortices on the back of the conical obstacle are investigated. The jet structure is better preserved and the vorticity value becomes larger as the impinging distance increases. Simulation results of the noise spectrums and overall sound pressure level (OASPL) agree well with the experimental data. The noise spectrums are analyzed and combined with simulation results for the flow field. When the impinging distance is small, the main acoustic sources with the broadband characteristic consist of the dipole source produced by pressure fluctuation on the surface of the obstacle, and the quadrupole source produced by vortices. As the impinging distance increases, the quadrupole source becomes the major acoustic source with low-frequency characteristics. In addition, the OASPL of the impinging jet is obtained at different impinging distances. (paper)

  10. Advanced Imaging in Femoroacetabular Impingement: Current State and Future Prospects

    OpenAIRE

    Bittersohl, Bernd; Hosalkar, Harish S.; Hesper, Tobias; Tiderius, Carl Johan; Zilkens, Christoph; Krauspe, R?diger

    2015-01-01

    Symptomatic femoroacetabular impingement (FAI) is now a known precursor of early osteoarthritis (OA) of the hip. In terms of clinical intervention, the decision between joint preservation and joint replacement hinges on the severity of articular cartilage degeneration. The exact threshold during the course of disease progression when the cartilage damage is irreparable remains elusive. The intention behind radiographic imaging is to accurately identify the morphology of osseous structural abn...

  11. Modelling of soft impingement during solidification

    Indian Academy of Sciences (India)

    TECS

    soft impingement problem and related to shape instability by constitutional supercooling theory. This analysis ... the context of the stir casting process, it has been pointed ... This transformation when applied to Fick's second law gives the ...

  12. Hip arthroscopy for femoroacetabular impingement

    Science.gov (United States)

    Nasser, Rima; Domb, Benjamin

    2018-01-01

    The purpose of this article is to give a general overview of femoroacetabular impingement (FAI) and how it could be treated arthroscopically, with some details about indications, the procedure itself and some of the complications associated with the surgery. FAI is a dynamic condition of the hip that can be a source of pain and disability and could potentially lead to arthritis. When symptomatic, and if conservative treatment fails, FAI can be addressed surgically. The goal of surgical treatment for FAI is to recreate the spherical contour of the femoral head, improve femoral offset, normalize coverage of the acetabulum, repair/reconstruct chondral damage and repair/reconstruct the labrum to restore normal mechanics and joint sealing. Advances in equipment and technique have contributed to an increase in the number of hip arthroscopy procedures performed worldwide and have made it one of the more common treatment options for symptomatic FAI. Hip arthroscopy is a procedure with an extremely steep and long learning curve. Cite this article: EFORT Open Rev 2018;3:121-129. DOI: 10.1302/2058-5241.3.170041 PMID:29780619

  13. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Directory of Open Access Journals (Sweden)

    Qiang WEI

    2017-08-01

    Full Text Available To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray, the conventional uncoupled spray model for impinging injectors is extended by considering the coupling of the jet impingement process and the ambient gas field. The new coupled model consists of the plain-orifice sub-model, the jet-jet impingement sub-model and the droplet collision sub-model. The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions. The overall model is benchmarked under various impingement angles, jet momentum and off-center ratios. Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics, such as the mass flux and mixture ratio distributions in quiescent air. Besides, impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions. First, a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile. The minimum average droplet diameter is achieved when the orifices work in cavitation state, and is about 30% smaller than the steady single phase state. Second, the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°. The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

  14. Coupled Lagrangian impingement spray model for doublet impinging injectors under liquid rocket engine operating conditions

    Institute of Scientific and Technical Information of China (English)

    Qiang WEI; Guozhu LIANG

    2017-01-01

    To predict the effect of the liquid rocket engine combustion chamber conditions on the impingement spray,the conventional uncoupled spray model for impinging injectors is extended by considering the couplingof the jet impingement process and the ambient gas field.The new coupled model consists of the plain-orifice sub-model,the jet-jet impingement sub-model and the droplet collision sub-model.The parameters of the child droplet are determined with the jet-jet impingement sub-model using correlations about the liquid jet parameters and the chamber conditions.The overall model is benchmarked under various impingement angles,jet momentum and offcenter ratios.Agreement with the published experimental data validates the ability of the model to predict the key spray characteristics,such as the mass flux and mixture ratio distributions in quiescent air.Besides,impinging sprays under changing ambient pressure and non-uniform gas flow are investigated to explore the effect of liquid rocket engine chamber conditions.First,a transient impingement spray during engine start-up phase is simulated with prescribed pressure profile.The minimum average droplet diameter is achieved when the orifices work in cavitation state,and is about 30% smaller than the steady single phase state.Second,the effect of non-uniform gas flow produces off-center impingement and the rotated spray fan by 38°.The proposed model suggests more reasonable impingement spray characteristics than the uncoupled one and can be used as the first step in the complex simulation of coupling impingement spray and combustion in liquid rocket engines.

  15. Pelvic morphology in ischiofemoral impingement

    International Nuclear Information System (INIS)

    Bredella, Miriam A.; Azevedo, Debora C.; Oliveira, Adriana L.; Simeone, Frank J.; Chang, Connie Y.; Torriani, Martin; Stubbs, Allston J.

    2015-01-01

    To assess MRI measures to quantify pelvic morphology that may predispose to ischiofemoral impingement (IFI). We hypothesized that patients with IFI have a wider interischial distance and an increased femoral neck angle compared with normal controls. The study was IRB-approved and complied with HIPAA guidelines. IFI was diagnosed based on clinical findings (hip or buttock pain) and ipsilateral edema of the quadratus femoris muscle on MRI. Control subjects did not report isolated hip/buttock pain and underwent MRI for surveillance of neoplasms or to exclude pelvic fractures. Two MSK radiologists measured the ischiofemoral (IF) and quadratus femoris (QF) distance, the ischial angle as a measure of inter-ischial distance, and the femoral neck angle. The quadratus femoris muscle was evaluated for edema. Groups were compared using ANOVA. Multivariate standard least-squares regression modeling was used to control for age and gender. The study group comprised 84 patients with IFI (53 ± 16 years, 73 female, 11 male) and 51 controls (52 ± 16 years, 33 female, 18 male). Thirteen out of 84 patients (15 %) had bilateral IFI. Patients with IFI had decreased IF and QF distance (p < 0.0001), increased ischial angle (p = 0.004), and increased femoral neck angle (p = 0.02) compared with controls, independent of age and gender. Patients with IFI have increased ischial and femoral neck angles compared with controls. These anatomical variations in pelvic morphology may predispose to IFI. MRI is a useful method of not only assessing the osseous and soft-tissue abnormalities associated with IFI, but also of quantifying anatomical variations in pelvic morphology that can predispose to IFI. (orig.)

  16. Pelvic morphology in ischiofemoral impingement

    Energy Technology Data Exchange (ETDEWEB)

    Bredella, Miriam A.; Azevedo, Debora C.; Oliveira, Adriana L.; Simeone, Frank J.; Chang, Connie Y.; Torriani, Martin [Massachusetts General Hospital, Department of Radiology, Musculoskeletal Imaging and Intervention, Boston, MA (United States); Stubbs, Allston J. [Wake Forest University School of Medicine, Department of Orthopedic Surgery, Division of Sports Medicine, Winston-Salem, NC (United States)

    2014-11-06

    To assess MRI measures to quantify pelvic morphology that may predispose to ischiofemoral impingement (IFI). We hypothesized that patients with IFI have a wider interischial distance and an increased femoral neck angle compared with normal controls. The study was IRB-approved and complied with HIPAA guidelines. IFI was diagnosed based on clinical findings (hip or buttock pain) and ipsilateral edema of the quadratus femoris muscle on MRI. Control subjects did not report isolated hip/buttock pain and underwent MRI for surveillance of neoplasms or to exclude pelvic fractures. Two MSK radiologists measured the ischiofemoral (IF) and quadratus femoris (QF) distance, the ischial angle as a measure of inter-ischial distance, and the femoral neck angle. The quadratus femoris muscle was evaluated for edema. Groups were compared using ANOVA. Multivariate standard least-squares regression modeling was used to control for age and gender. The study group comprised 84 patients with IFI (53 ± 16 years, 73 female, 11 male) and 51 controls (52 ± 16 years, 33 female, 18 male). Thirteen out of 84 patients (15 %) had bilateral IFI. Patients with IFI had decreased IF and QF distance (p < 0.0001), increased ischial angle (p = 0.004), and increased femoral neck angle (p = 0.02) compared with controls, independent of age and gender. Patients with IFI have increased ischial and femoral neck angles compared with controls. These anatomical variations in pelvic morphology may predispose to IFI. MRI is a useful method of not only assessing the osseous and soft-tissue abnormalities associated with IFI, but also of quantifying anatomical variations in pelvic morphology that can predispose to IFI. (orig.)

  17. Diagnostic Accuracy of Clinical Examination and Imaging Findings for Identifying Subacromial Pain.

    Science.gov (United States)

    Cadogan, Angela; McNair, Peter J; Laslett, Mark; Hing, Wayne A

    2016-01-01

    The diagnosis of subacromial pathology is limited by the poor accuracy of clinical tests for specific pathologies. The aim of this study was to estimate the diagnostic accuracy of clinical examination and imaging features for identifying subacromial pain (SAP) defined by a positive response to diagnostic injection, and to evaluate the influence of imaging findings on the clinical diagnosis of SAP. In a prospective, diagnostic accuracy design, 208 consecutive patients presenting to their primary healthcare practitioner for the first time with a new episode of shoulder pain were recruited. All participants underwent a standardized clinical examination, shoulder x-ray series and diagnostic ultrasound scan. Results were compared with the response to a diagnostic block of xylocaineTM injected into the SAB under ultrasound guidance using ≥80% post-injection reduction in pain intensity as the positive anaesthetic response (PAR) criterion. Diagnostic accuracy statistics were calculated for combinations of clinical and imaging variables demonstrating the highest likelihood of a PAR. A PAR was reported by 34% of participants. In participants with no loss of passive external rotation, combinations of three clinical variables (anterior shoulder pain, strain injury, absence of symptoms at end-range external rotation (in abduction)) demonstrated 100% specificity for a PAR when all three were positive (LR+ infinity; 95%CI 2.9, infinity). A full-thickness supraspinatus tear on ultrasound increased the likelihood of a PAR irrespective of age (specificity 98% (95%CI 94, 100); LR+ 6.2; 95% CI 1.5, 25.7)). Imaging did not improve the ability to rule-out a PAR. Combinations of clinical examination findings and a full-thickness supraspinatus tear on ultrasound scan can help confirm, but not exclude, the presence of subacromial pain. Other imaging findings were of limited value for diagnosing SAP.

  18. Postoperative fentanyl patch versus subacromial bupivacaine infusion in arthroscopic shoulder surgery.

    Science.gov (United States)

    Merivirta, Riika; Äärimaa, Ville; Aantaa, Riku; Koivisto, Mari; Leino, Kari; Liukas, Antti; Kuusniemi, Kristiina

    2013-07-01

    The purpose of our study was to compare the effectiveness of subacromial bupivacaine infusion and a transdermal fentanyl patch in the treatment of postoperative pain after arthroscopic shoulder surgery. Sixty patients with rotator cuff disease scheduled for elective arthroscopic shoulder surgery were enrolled in the study. For the treatment of postoperative pain, 30 patients constituted group F and received a 12.0-μg/h fentanyl patch for 72 hours and saline solution infusion in a subacromial manner at the rate of 4 mL/h. The remaining 30 patients constituted group B and received a placebo patch and an infusion of 2.5-mg/mL bupivacaine in a subacromial manner for 72 hours. The primary outcome measure was the postoperative numerical rating scale pain score. The consumption of opioids, ibuprofen, and acetaminophen was also recorded. The Constant scores and general recovery were followed up until the 90th postoperative day. There was no statistically significant difference in the numerical rating scale scores (P = .60) between the groups. No differences in the use of rescue analgesic were observed except that the patients receiving bupivacaine used more ibuprofen (median, 1,200 mg v 600 mg) during the day of surgery (P = .042). No difference was found in general recovery between the groups. A fentanyl patch delivering 12-μg/h fentanyl offers an easy and safe treatment option as a part of multimodal analgesia with few adverse effects in the treatment of postoperative pain in a carefully selected patient group after arthroscopic shoulder surgery. Level I, randomized controlled trial. Copyright © 2013 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

  19. Imaging findings of femoroacetabular impingement syndrome

    International Nuclear Information System (INIS)

    Beall, Douglas P.; Sweet, Clifford F.; Martin, Hal D.; Lastine, Craig L.; Grayson, David E.; Ly, Justin Q.; Fish, Jon R.

    2005-01-01

    Femoroacetabular impingement syndrome (FAI) is a pathologic entity which can lead to chronic symptoms of pain, reduced range of motion in flexion and internal rotation, and has been shown to correlate with degenerative arthritis of the hip. History, physical examination, and supportive radiographic findings such as evidence of articular cartilage damage, acetabular labral tearing, and early-onset degenerative changes can help physicians diagnose this entity. Several pathologic changes of the femur and acetabulum are known to predispose patients to develop FAI and recognition of these findings can ultimately lead to therapeutic interventions. The two basic mechanisms of impingement - cam impingement and pincer impingement - are based on the type of anatomic anomaly contributing to the impingement process. These changes can be found on conventional radiography, MR imaging, and CT examinations. However, the radiographic findings of this entity are not widely discussed and recognized by physicians. In this paper, we will introduce these risk factors, the proposed supportive imaging criteria, and the ultimate interventions that can help alleviate patients' symptoms. (orig.)

  20. Imaging findings of femoroacetabular impingement syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Beall, Douglas P.; Sweet, Clifford F.; Martin, Hal D.; Lastine, Craig L.; Grayson, David E.; Ly, Justin Q.; Fish, Jon R. [University of Oklahoma Health Sciences Center, Department of Radiologal Sciences, Oklahoma City (United States)

    2005-11-01

    Femoroacetabular impingement syndrome (FAI) is a pathologic entity which can lead to chronic symptoms of pain, reduced range of motion in flexion and internal rotation, and has been shown to correlate with degenerative arthritis of the hip. History, physical examination, and supportive radiographic findings such as evidence of articular cartilage damage, acetabular labral tearing, and early-onset degenerative changes can help physicians diagnose this entity. Several pathologic changes of the femur and acetabulum are known to predispose patients to develop FAI and recognition of these findings can ultimately lead to therapeutic interventions. The two basic mechanisms of impingement - cam impingement and pincer impingement - are based on the type of anatomic anomaly contributing to the impingement process. These changes can be found on conventional radiography, MR imaging, and CT examinations. However, the radiographic findings of this entity are not widely discussed and recognized by physicians. In this paper, we will introduce these risk factors, the proposed supportive imaging criteria, and the ultimate interventions that can help alleviate patients' symptoms. (orig.)

  1. Calculations of slurry pump jet impingement loads

    International Nuclear Information System (INIS)

    Wu, T.T.

    1996-01-01

    This paper presents a methodology to calculate the impingement load in the region of a submerged turbulent jet where a potential core exits and the jet is not fully developed. The profile of the jet flow velocities is represented by a piece-wise linear function which satisfies the conservation of momentum flux of the jet flow. The adequacy of the of the predicted jet expansion is further verified by considering the continuity of the jet flow from the region of potential core to the fully developed region. The jet impingement load can be calculated either as a direct impingement force or a drag force using the jet velocity field determined by the methodology presented

  2. Effects of Repetitive Shoulder Activity on the Subacromial Space in Manual Wheelchair Users

    Directory of Open Access Journals (Sweden)

    Yen-Sheng Lin

    2014-01-01

    Full Text Available This study investigated (1 the effect of repetitive weight-relief raises (WR and shoulder external rotation (ER on the acromiohumeral distance (AHD among manual wheelchair users (MWUs and (2 the relationship between shoulder pain, subject characteristics, and AHD changes. Twenty-three MWUs underwent ultrasound imaging of the nondominant shoulder in an unloaded baseline position and while holding a WR position before and after the WR/ER tasks. Paired t-tests and Spearman correlational analysis were used to assess differences in the AHD before and after each task and the relationships between pain, subject characteristics, and the AHD measures. A significant reduction in the subacromial space (P<0.01 occurred when subjects performed a WR position compared to baseline. Individuals with increased years of disability had greater AHD percentage narrowing after WR (P=0.008. Increased shoulder pain was associated with AHD percentage narrowing after ER (P≤0.007. The results support clinical practice guidelines that recommend MWUs limit WR to preserve shoulder function. The isolated repetitive shoulder activity did not contribute to the changes of subacromial space in MWUs. The ultrasonographic measurement of the AHD may be a target for identifying future interventions that prevent pain.

  3. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    José L. Arias-Buría

    2015-01-01

    Full Text Available Objective. To compare effects of ultrasound- (US- guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n=17 group or exercise (n=19 group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions. Shoulder pain (NPRS and disability (DASH were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P<0.01: individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

  4. Rotator cuff healing after continuous subacromial bupivacaine infusion: an in vivo rabbit study

    Science.gov (United States)

    FRIEL, NICOLE A.; WANG, VINCENT M.; SLABAUGH, MARK A.; WANG, FANCHIA; CHUBINSKAYA, SUSAN; COLE, BRIAN J.

    2013-01-01

    Background The objective of this study was to evaluate the effects of continuous subacromial bupivacaine infusion on supraspinatus muscle and rotator cuff tendon healing via gross, biomechanical, and histologic analyses. Methods Thirty-three New Zealand White rabbits underwent unilateral supraspinatus transection and rotator cuff repair (RCR). Rabbits were assigned to 1 of 3 groups: (1)RCR only, (2)RCR with continuous saline infusion for 48 hours, or (3)RCR with continuous 0.25% bupivacaine with epinephrine (1:200,000) infusion for 48 hours. Rabbits were sacrificed at either 2 (for histologic assessment) or 8 weeks post-operatively (for biomechanical and histologic assessment). Results Tensile testing showed significantly higher load to failure in intact tendons compared to repaired tendons (pBupivacaine groups. Histologically, the enthesis of repaired tendons showed increased cellularity and disorganized collagen fibers compared to intact tendons, with no differences between treatment groups. Muscle histology demonstrated scattered degenerative muscle fibers at 2 weeks in both RCR Saline and RCR Bupivacaine, but no degeneration was noted at 8 weeks. Conclusions The healing supraspinatus tendons exposed to bupivacaine infusion showed similar histologic and biomechanical characteristics compared to untreated and saline infused RCR groups. Muscle histology showed fiber damage at 2 weeks for both the saline and bupivacaine treated groups, with no apparent disruption at 8 weeks, suggesting a recovery process. Therefore, subacromial bupivacaine infusion in this rabbit rotator cuff model does not appear to impair muscle or tendon following acute injury and repair. Level Of Evidence Basic science study PMID:22818894

  5. Accuracy of diagnostic ultrasound in patients with suspected subacromial disorders: a systematic review and meta-analysis.

    NARCIS (Netherlands)

    Ottenheijm, R.P.; Jansen, M.J.; Staal, J.B.; Bruel, A. van den; Weijers, R.E.; Bie, R.A. de; Dinant, G.J.

    2010-01-01

    OBJECTIVE: To determine the diagnostic accuracy of ultrasound for detecting subacromial disorders in patients presenting in primary and secondary care settings. DATA SOURCES: Medline and Embase were searched on June 9, 2010. In addition, the reference list of 1 systematic review and all included

  6. Physical Modelling of Axisymmetric Turbulent Impinging Jets as used within the Nuclear Industry for Mobilisation of Sludges

    International Nuclear Information System (INIS)

    McKendrick, D.; Biggs, S.R.; Fairweather, M.; Rhodes, D.

    2008-01-01

    The impingement of a fluid jet onto a surface has broad applications across many industries. Within the UK nuclear industry, during the final stages of fuel reprocessing, impinging fluid jets are utilised to mobilise settled sludge material within storage tanks and ponds in preparation for transfer and ultimate immobilisation through vitrification. Despite the extensive applications of impinging jets within the nuclear and other industries, the study of two-phase, solid loaded, impinging jets is limited, and generally restricted to computational modelling. Surprisingly, very little fundamental understanding of the turbulence structure within such fluid flows through experimental investigation is found within the literature. The physical modelling of impinging jet systems could successfully serve to aid computer model validation, determine operating requirements, evaluate plant throughput requirements, optimise process operations and support design. Within this project a method is illustrated, capable of exploring the effects of process and material variables on flow phenomena of impinging jets. This is achieved via the use of non-intrusive measurement techniques Particle Image Velocimetry (PIV), Ultrasonic Doppler Velocity Profiler (UDVP) and high speed imaging. The turbulence structure for impinging jets, and their resultant radial wall jets, is presented at different jet-to-plate ratios, jet Reynolds numbers and jet outlet diameters. (authors)

  7. Os acromiale causing shoulder impingement syndrome: a case report

    International Nuclear Information System (INIS)

    Romero, I.; Rodriguez, A.; Roca, M.; Garcia, Y.

    2001-01-01

    Shoulder impingement syndrome is caused by repeated mechanical trauma to the rotator cuff due to encroachment of the coracoacromial ligament; in most cases, it is a primary lesion. Os acromiale, an anatomic variant of the shoulder structures, is one of the predisposing factors for the development of this entity. We present a case of os acromiale complicated by complete rupture of the tendon of the supraspinatus muscle and luxation of the long head of the biceps tendon. We stress the importance of magnetic resonance in the study of this anatomic variant and in the detection of complications or associated lesions. (Author) 10 refs

  8. Femoroacetabular impingement mimicking avascular osteonecrosis on bone scintigraphy

    International Nuclear Information System (INIS)

    Suarez, Juan Pablo; Domínguez, María Luz; Nogareda, Zulema; Gómez, María Asunción; Muñoz, Jose

    2016-01-01

    Femoroacetabular impingement (FAI) is a structural abnormality of proximal femur and/or acetabulum. It has been recently described, and there are limited reports in nuclear medicine literature because bone scintigraphy is not listed in its diagnostic protocol, but it should be included on differential diagnosis when evaluating patients, with hip-related symptoms because it may be misinterpreted as degenerative changes or avascular necrosis, and its early treatment avoid progression to osteoarthritis. We describe the case of a male who suffered from hip pain. Bone planar scintigraphic appearance mimicked avascular necrosis, but single photon emission computed tomography (CT) imaging and CT examination confirmed the diagnosis of FAI

  9. Surgical criteria for femoroacetabular impingement syndrome

    DEFF Research Database (Denmark)

    Peters, Scott; Laing, Alisha; Emerson, Courtney

    2017-01-01

    BACKGROUND: The purpose of this review was to analyse and report criteria used for open and arthroscopic surgical treatment of femoroacetabular impingement syndrome (FAIS). METHODS: A librarian-assisted computer search of Medline, CINAHL and Embase for studies related to criterion for FAIS surgery...

  10. Transverse jet-cavity interactions with the influence of an impinging shock

    International Nuclear Information System (INIS)

    Zare-Behtash, H.; Lo, K.H.; Kontis, K.; Ukai, T.; Obayashi, S.

    2015-01-01

    Highlights: • Experimental study of shock-jet-cavity in a supersonic freestream is conducted. • Shock impingement at the cavity leading edge lifts the shear layer, encouraging momentum transfer. • Shock impingement close to the jet location increases the number of smaller turbulent structures. - Abstract: For high-speed air breathing engines, fuel injection and subsequent mixing with air is paramount for combustion. The high freestream velocity poses a great challenge to efficient mixing both in macroscale and microscale. Utilising cavities downstream of fuel injection locations, as a means to hold the flow and stabilise the combustion, is one mechanism which has attracted much attention, requiring further research to study the unsteady flow features and interactions occurring within the cavity. In this study we combine the transverse jet injection upstream of a cavity with an impinging shock to see how this interaction influences the cavity flow, since impinging shocks have been shown to enhance mixing of transverse jets. Utilising qualitative and quantitative methods: schlieren, oilflow, PIV, and PSP the induced flowfield is analysed. The impinging shock lifts the shear layer over the cavity and combined with the instabilities generated by the transverse jet creates a highly complicated flowfield with numerous vertical structures. The interaction between the oblique shock and the jet leads to a relatively uniform velocity distribution within the cavity

  11. Targeted knockout of TNF-α by injection of lentivirus-mediated siRNA into the subacromial bursa for the treatment of subacromial bursitis in rats.

    Science.gov (United States)

    Wang, Yi; Li, Quan; Wei, Xianzhao; Xu, Jie; Chen, Qi; Song, Shuang; Lu, Zhe; Wang, Zimin

    2015-09-01

    Subacromial bursitis (SAB) is the major source of pain in rotator cuff disease. Although multiple investigations have provided support for the role of inflammatory cytokines in SAB, few have focussed on the use these cytokines in the treatment of SAB. The aim of the present study was to observe the therapeutic efficacy of lentivirus‑mediated RNA interference (RNAi) on carrageenan‑induced SAB by injecting lentivirus‑tumor necrosis factor (TNF)‑α‑RNAi expressing TNF‑α small interfering (si)RNA. Using screened siRNA segments, an siRNA was designed. A lentivirus vector expressing siRNA was established and packed as lentivirus particles. A lentivirus that expressed the negative sequence was used as a lentivirus‑negative control (NC). The carrageenan‑induced SAB model was established in 32 male Sprague‑Dawley rats. The modeled rats were randomly assigned to four groups: Lentivirus‑RNAi treatment group, lentivirus‑NC group, SAB group and phosphate‑buffered saline (PBS) blank control group. The lentivirus was injected (1x10(7) transducing units) into the subacromial bursa of the rats in the lentivirus‑RNAi group and lentivirus‑NC group, whereas 100 µl PBS was injected at the same site in the SAB group and the PBS blank control group. At 5 weeks following injection, the animals were sacrificed and venous blood was obtained. The effect of TNF‑α interference and the expression of inflammatory cytokines were determined by reverse transcription‑quantitative polymerase chain reaction, western blotting, hematoxylin and eosin staining, Van Gieson's staining and immunofluorescence. The expression of TNF‑α was decreased in the lentivirus‑TNF‑α‑RNAi group compared with that in the SAB group. Morphological observations revealed that the number of inflammatory cells were reduced and damage to tendon fibers was attenuated in this group, suggesting that the downregulation of the protein expression levels of TNF‑α‑associated nuclear

  12. Glenohumeral and scapulothoracic strength impairments exists in patients with subacromial impingement, but these are not reflected in the shoulder pain and disability index

    DEFF Research Database (Denmark)

    Clausen, M B; Witten, A; Holm, K

    2017-01-01

    in strength and ROM to patient-reported shoulder function is not well described, even though testing of strength is recommended in clinical guidelines. The purpose of this study was, first, to investigate impairments in glenohumeral and scapulothoracic strength and in abduction and internal rotation ROM...

  13. Selective activation of intra-muscular compartments within the trapezius muscle in subjects with Subacromial Impingement Syndrome. A case-control study

    DEFF Research Database (Denmark)

    Larsen, C M; Juul-Kristensen, B; Olsen, H B

    2014-01-01

    Neuromuscular control of the scapular muscles is important in the etiology of shoulder pain. Electromyographical (EMG) biofeedback in healthy people has been shown to support a selective activation of the lower compartment of the trapezius muscle, specifically. The aim of the present paper was to...

  14. Impingement of juvenile and adult fishes during cooling water withdrawal

    International Nuclear Information System (INIS)

    McFarlane, R.W.

    1978-01-01

    Juvenile and adult fishes are impinged upon trash removal screens as Savannah River water is withdrawn for use on the Savannah River Plant (SRP). Thirty-six species of fish, representing half of all riverine species known from the area, were impinged on the screens at three SRP pumping stations during 1977. Based on the average of 11.2 fish impinged per day, annual impingement is estimated to be 4088 fish. SRP thus ranks third lowest for impingement recently reported for 33 electric power plants

  15. Magnetic Resonance Imaging of Rotator Cuff Tears in Shoulder Impingement Syndrome

    International Nuclear Information System (INIS)

    Freygant, Magdalena; Dziurzyńska-Białek, Ewa; Guz, Wiesław; Samojedny, Antoni; Gołofit, Andrzej; Kostkiewicz, Agnieszka; Terpin, Krzysztof

    2014-01-01

    Shoulder joint is a common site of musculoskeletal pain caused, among other things, by rotator cuff tears due to narrowing of subacromial space, acute trauma or chronic shoulder overload. Magnetic resonance imaging (MRI) is an excellent modality for imaging of soft tissues of the shoulder joint considering a possibility of multiplanar image acquisition and non-invasive nature of the study. The aim of this study was to evaluate the prevalence of partial and complete rotator cuff tears in magnetic resonance images of patients with shoulder impingement syndrome and to review the literature on the causes and classification of rotator cuff tears. We retrospectively analyzed the results of 137 shoulder MRI examinations performed in 57 women and 72 men in Magnetic Resonance facility of the Department of Radiology and Diagnostic Imaging at the St. Jadwiga the Queen Regional Hospital No. 2 in Rzeszow between June 2010 and February 2013. Examinations were performed using Philips Achieva 1.5T device, including spin echo and gradient echo sequences with T1-, T2- and PD-weighted as well as fat saturation sequences in transverse, frontal and sagittal oblique planes. Patients were referred from hospital wards as well as from outpatient clinics of the subcarpathian province. The most frequently reported injuries included partial supraspinatus tendon tear and complete tearing most commonly involved the supraspinatus muscle tendon. The smallest group comprised patients with complete tear of subscapularis muscle tendon. Among 137 patients in the study population, 129 patients suffered from shoulder pain, including 57 patients who reported a history of trauma. There was 44% women and 56% men in a group of patients with shoulder pain. Posttraumatic shoulder pain was predominantly reported by men, while women comprised a larger group of patients with shoulder pain not preceded by injury. Rotator cuff injury is a very common pathology in patients with shoulder impingement syndrome

  16. Numerical study of a confined slot impinging jet with nanofluids

    Directory of Open Access Journals (Sweden)

    Manca Oronzio

    2011-01-01

    Full Text Available Abstract Background Heat transfer enhancement technology concerns with the aim of developing more efficient systems to satisfy the increasing demands of many applications in the fields of automotive, aerospace, electronic and process industry. A solution for obtaining efficient cooling systems is represented by the use of confined or unconfined impinging jets. Moreover, the possibility of increasing the thermal performances of the working fluids can be taken into account, and the introduction of nanoparticles in a base fluid can be considered. Results In this article, a numerical investigation on confined impinging slot jet working with a mixture of water and Al2O3 nanoparticles is described. The flow is turbulent and a constant temperature is applied on the impinging. A single-phase model approach has been adopted. Different geometric ratios, particle volume concentrations and Reynolds number have been considered to study the behavior of the system in terms of average and local Nusselt number, convective heat transfer coefficient and required pumping power profiles, temperature fields and stream function contours. Conclusions The dimensionless stream function contours show that the intensity and size of the vortex structures depend on the confining effects, given by H/W ratio, Reynolds number and particle concentrations. Furthermore, for increasing concentrations, nanofluids realize increasing fluid bulk temperature, as a result of the elevated thermal conductivity of mixtures. The local Nusselt number profiles show the highest values at the stagnation point, and the lowest at the end of the heated plate. The average Nusselt number increases for increasing particle concentrations and Reynolds numbers; moreover, the highest values are observed for H/W = 10, and a maximum increase of 18% is detected at a concentration equal to 6%. The required pumping power as well as Reynolds number increases and particle concentrations grow, which is almost 4

  17. Temporally stratified sampling programs for estimation of fish impingement

    International Nuclear Information System (INIS)

    Kumar, K.D.; Griffith, J.S.

    1977-01-01

    Impingement monitoring programs often expend valuable and limited resources and fail to provide a dependable estimate of either total annual impingement or those biological and physicochemical factors affecting impingement. In situations where initial monitoring has identified ''problem'' fish species and the periodicity of their impingement, intensive sampling during periods of high impingement will maximize information obtained. We use data gathered at two nuclear generating facilities in the southeastern United States to discuss techniques of designing such temporally stratified monitoring programs and their benefits and drawbacks. Of the possible temporal patterns in environmental factors within a calendar year, differences among seasons are most influential in the impingement of freshwater fishes in the Southeast. Data on the threadfin shad (Dorosoma petenense) and the role of seasonal temperature changes are utilized as an example to demonstrate ways of most efficiently and accurately estimating impingement of the species

  18. The Relationship Between Pulsatile Flow Impingement and Intraluminal Thrombus Deposition in Abdominal Aortic Aneurysms.

    Science.gov (United States)

    Lozowy, Richard J; Kuhn, David C S; Ducas, Annie A; Boyd, April J

    2017-03-01

    Direct numerical simulations were performed on four patient-specific abdominal aortic aneurysm (AAA) geometries and the resulting pulsatile blood flow dynamics were compared to aneurysm shape and correlated with intraluminal thrombus (ILT) deposition. For three of the cases, turbulent vortex structures impinged/sheared along the anterior wall and along the posterior wall a zone of recirculating blood formed. Within the impingement region the AAA wall was devoid of ILT and remote to this region there was an accumulation of ILT. The high wall shear stress (WSS) caused by the impact of vortexes is thought to prevent the attachment of ILT. WSS from impingement is comparable to peak-systolic WSS in a normal-sized aorta and therefore may not damage the wall. Expansion occurred to a greater extent in the direction of jet impingement and the wall-normal force from the continuous impact of vortexes may contribute to expansion. It was shown that the impingement region has low oscillatory shear index (OSI) and recirculation zones can have either low or high OSI. No correlation could be identified between OSI and ILT deposition since different flow dynamics can have similar OSI values.

  19. What is the impingement-free range of motion of the asymptomatic hip in young adult males?

    Science.gov (United States)

    Larkin, Brian; van Holsbeeck, Marnix; Koueiter, Denise; Zaltz, Ira

    2015-04-01

    Femoroacetabular impingement is a recognized cause of chondrolabral injury. Although surgical treatment for impingement seeks to improve range of motion, there are very little normative data on dynamic impingement-free hip range of motion (ROM) in asymptomatic people. Hip ultrasound demonstrates labral anatomy and femoral morphology and, when used dynamically, can assist in measuring range of motion. The purposes of this study were (1) to measure impingement-free hip ROM until labral deflection is observed; and (2) to measure the maximum degree of sagittal plane hip flexion when further flexion is limited by structural femoroacetabular abutment. Forty asymptomatic adult male volunteers (80 hips) between the ages of 21 and 35 years underwent bilateral static and dynamic hip ultrasound examination. Femoral morphology was characterized and midsagittal flexion passive ROM was measured at two points: (1) at the initiation of labral deformation; and (2) at maximum flexion when the femur impinged on the acetabular rim. The mean age of the subjects was 28 ± 3 years and the mean body mass index was 25 ± 4 kg/m(2). Mean impingement-free hip passive flexion measured from full extension to initial labral deflection was 68° ± 17° (95% confidence interval [CI], 65-72). Mean maximum midsagittal passive flexion, measured at the time of bony impingement, was 96° ± 6° (95% CI, 95-98). Using dynamic ultrasound, we found that passive ROM in the asymptomatic hip was much less than the motion reported in previous studies. Measuring ROM using ultrasound is more accurate because it allows anatomic confirmation of terminal hip motion. Surgical procedures used to treat femoroacetabular impingement are designed to restore or increase hip ROM and their results should be evaluated in light of precise normative data. This study suggests that normal passive impingement-free femoroacetabular flexion in the young adult male is approximately 95°.

  20. Suture slippage in knotless suture anchors resulting in subacromial-subdeltoid bursitis.

    Science.gov (United States)

    Hayeri, Mohammad Reza; Keefe, Daniel T; Chang, Eric Y

    2016-05-01

    Rotator cuff repair using a suture bridge and knotless suture anchors is a relatively new, but increasingly used technique. The suture bridge technique creates an anatomically similar and more secure rotator cuff repair compared with conventional arthroscopic techniques and the use of knotless anchors eliminates the challenges associated with knot tying during arthroscopic surgery. However, previous in vitro biomechanical tests have shown that the hold of the suture in a knotless suture anchor is far lower than the pullout strength of the anchor from bone. Up until now slippage has been a theoretical concern. We present a prospectively diagnosed case of in vivo suture loosening after rotator cuff repair using a knotless bridge technique resulting in subacromial-subdeltoid bursitis.

  1. Arthroscopic Treatment of a Case with Concomitant Subacromial and Subdeltoid Synovial Chondromatosis and Labrum Tear

    Directory of Open Access Journals (Sweden)

    Nevres Hurriyet Aydogan

    2013-01-01

    Full Text Available Synovial chondromatosis is a disease that seldomly seen in shoulder joint and is related to benign synovial proliferation and synchronous chondral tissue formation within the joint cavity. Patients suffer from progressive restriction of range of motion and shoulder pain. Extra-articular involvement is an extremely rare condition. Degenerative osteoarthritis, joint subluxation, and bursitis are common complications in untreated patients. Open or arthroscopic surgery is suitable while there is no consensus related to superiority of different approaches. We presented an arthroscopic treatment of a male patient, 48 years old with labrum tear and synovial chondromatosis localized in subacromial and subdeltoid region. Advantages of arthroscopic surgery in the presence of intra- and extra-articular combined pathologies are also discussed.

  2. Pathological Fracture of Clavicle Following Sub-Acromial Decompression-Infraclavicular Compartment Syndrome?

    Directory of Open Access Journals (Sweden)

    S Mukhopadhyay

    2009-11-01

    Full Text Available A 34-year-old factory worker presented with pain and weakness of the left shoulder following a fall on ice on her left shoulder. An ultrasound scan of the shoulder taken 4 months after injury showed small partial articular surface tear of the supraspinatus tendon. Ten days following subacromial decompression she suffered a pathological fracture of her left clavicle. MRI, CT, and isotope bone scans showed no evidence of malignancy or infection but a collection of fluid was noted underlying the clavicle communicating to the acromioclavicular joint. Ultrasound scan guided aspiration of 20 millilitres of bloodstained fluid underlying the clavicle resulted in gradual recovery and adequate healing of the fracture.

  3. Impinging jet spray formation using non-Newtonian liquids

    Science.gov (United States)

    Rodrigues, Neil S.

    and drop velocity mean values and distribution of several non-Newtonian liquids using a like-on-like impinging jet doublet. The drop size and drop velocity are important areas of study because of the effect on mass transfer and mass dispersal. Phase Doppler Anemometry (PDA) is used to measure the drop diameter and drop velocity. The drop diameter is measured by finding a phase difference between two signals. The drop velocity is measured using Laser Doppler Anemometry (LDA), which is based on the Doppler shift. Parametric studies are conducted based on dimensionless groups, impinging jet geometry, and spatial position. The investigated non-Newtonian liquids collapse onto a single mean diameter versus Reynolds number curve. However, this behavior is not observed for the gels due to differences in surface tension and molecular structure. In general, increasing the inertial force results in smaller drops and greater drop velocities. The different geometric parameters are observed to have varying degrees of influence, based on the propellant simulant considered. Larger drops with lower axial velocities are generally observed with increasing transverse distances from the centerline of the impinging jet spray.

  4. Impinging jets controlled by fluidic input signal

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav; Trávníček, Zdeněk; Peszyński, K.

    2016-01-01

    Roč. 249, October (2016), s. 85-92 ISSN 0924-4247 R&D Projects: GA ČR GA13-23046S; GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : fluidics * jets * impinging jets * coanda effect Subject RIV: BK - Fluid Dynamics Impact factor: 2.499, year: 2016 http://www.sciencedirect.com/science/article/pii/S0924424716303880

  5. Gas turbine bucket with impingement cooled platform

    Science.gov (United States)

    Jones, Raphael Durand

    2002-01-01

    In a turbine bucket having an airfoil portion and a root portion, with a substantially planar platform at an interface between the airfoil portion and root portion, a platform cooling arrangement including at least one bore in the root portion and at least one impingement cooling tube seated in the bore, the tube extending beyond the bore with an outlet in close proximity to a targeted area on an underside of the platform.

  6. Ischiofemoral impingement syndrome: a meta-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Adam D.; Subhawong, Ty K.; Jose, Jean; Tresley, Jonathan; Clifford, Paul D. [Jackson Memorial Hospital, Department of Diagnostic Radiology, Section of Musculoskeletal Imaging, Miami, FL (United States)

    2015-06-01

    The aims of this article are to review the imaging characteristics of ischiofemoral impingement (IFI), summarize measurement thresholds for radiologic diagnosis based on a meta-analysis of the literature and raise awareness among radiologists and clinicians of this entity. A PubMed search restricted to the English language containing the keywords ''ischiofemoral impingement'' and ''quadratus femoris MRI'' was performed, and citations in these articles were also used to identify a total of 27 studies discussing ischiofemoral impingement. After excluding case reports and non-representative studies, there were five remaining articles including 193 hip MRIs of IFI in 154 subjects (133 female, 21 male) and 135 asymptomatic control hip MRIs from 74 subjects (55 female, 19 male). Additionally, we performed a retrospective database search of pelvic and hip MRI reports from our institution including the terms ''quadratus femoris'' or ''ischiofemoral impingement'' from a 9-year period and 24 hip MRIs from 21 patients (18 female, 3 male) with IFI with 5 asymptomatic contralateral control hip MRIs identified. In all, 217 hip MRIs of IFI and 140 control cases were included. A meta-analysis of these hip MRIs was conducted to determine optimal thresholds of the ischiofemoral space (IFS) and quadratus femoris space (QFS) for identifying IFI. Cases of IFI showed significantly smaller IFS and QFS compared to controls (14.91 ± 4.8 versus 26.01 ± 7.98 and 9.57 ± 3.7 versus 15.97 ± 6.07, measured in mm, respectively, p < 0.0001 for both). Pooled analysis revealed that for IFS, using a cutoff of ≤15 mm yielded a sensitivity of 76.9 %, specificity of 81.0 % and overall accuracy of 78.3 %. For QFS, a cutoff of ≤ 10.0 mm resulted in 78.7 % sensitivity, 74.1 % specificity and 77.1 % overall accuracy. IFI is a potential cause of hip pain that can be accurately diagnosed with MRI in conjunction with

  7. Hip morphology predicts posterior hip impingement in a cadaveric model.

    Science.gov (United States)

    Morris, William Z; Fowers, Cody A; Weinberg, Douglas S; Millis, Michael B; Tu, Leigh-Anne; Liu, Raymond W

    2018-05-01

    Posterior hip impingement is a recently-identified cause of hip pain. The purpose of this study is to characterise posterior femoroacetabular and ischiofemoral impingement and identify its predisposing morphologic traits. Two hundred and six cadaveric hips were randomly selected and taken through controlled motion in two pure axes associated with posterior hip impingement: external rotation (through the mechanical axis) and adduction (coronal plane). The range of motion and location of impingement was noted for each specimen. Morphologic traits including femoral/acetabular version, and true neck-shaft angle (TNSA) were also measured. External rotation impingement occurred between the femoral neck and acetabulum in 83.0% of hips, and between the lesser trochanter and ischial tuberosity in 17.0%. Adduction impingement occurred between the lesser trochanter and ischial tuberosity in 78.6% of hips, and between the femoral neck and acetabulum in 21.4%. Multiple regression revealed that increased femoral/acetabular version predicted earlier external rotation and adduction impingement. Unstandardised betas ranging from -0.39 to -0.64 reflect that each degree of increased femoral/acetabular version individually accounts for a loss of external rotation or adduction of approximately half a degree before impingement ( p < 0.001 for each). Increased TNSA was associated with earlier adduction impingement only (unstandardised beta -0.35, p = 0.005). Relative femoral/acetabular anteversion was associated with earlier posterior hip impingement. Coxa valga was associated with earlier adduction impingement, but protective against external rotation impingement. These findings highlight the importance of monitoring correction during femoral/acetabular osteotomies, as overcorrection of retroversion may predispose to earlier posterior impingement.

  8. The Strengthening Exercises in Shoulder Impingement trial (The SExSI-trial) investigating the effectiveness of a simple add-on shoulder strengthening exercise programme in patients with long-lasting subacromial impingement syndrome

    DEFF Research Database (Denmark)

    Clausen, Mikkel Bek; Bandholm, Thomas; Rathleff, Michael Skovdal

    2018-01-01

    with pronounced and long-lasting SIS. However, the current rehabilitation of such strength impairments may be inadequate, with novel rehabilitation programmes including exercise therapy only improving external rotation strength by 4-13%. As these previous studies are the basis of current practice, this suggests...... that the strengthening component could be inadequate in the rehabilitation of these patients, and it seems likely that more emphasis should be placed on intensifying this part of the rehabilitation. The purpose of this study is to investigate the effectiveness of a programme consisting of progressive home...... with pronounced and long-lasting SIS, diagnosed using predefined criteria. Participants will be randomised to receive either an add-on intervention of progressive home-based resistance training using an elastic band in addition to usual care or usual care alone in a 1:1 allocation ratio. The randomisation...

  9. MR imaging after rotator cuff repair: full-thickness defects and bursitis-like subacromial abnormalities in asymptomatic subjects

    International Nuclear Information System (INIS)

    Zanetti, M.; Hodler, J.; Jost, B.; Gerber, C.

    2000-01-01

    Objective. To determine the prevalence and extent of residual defects or retears and bursitis-like subacromial abnormalities on MR images after rotator cuff repair in asymptomatic subjects, and to define the clinical relevance of these findings.Design and patients. Fourteen completely asymptomatic patients and 32 patients with residual symptoms were investigated 27-53 months (mean 39 months) after open transosseous reinsertion of the rotator cuff. Coronal T2-weighted turbo spin-echo and turbo STIR or T2-weighted fat-suppressed MR images were obtained. The prevalence and extent of residual defects or retears of the rotator cuff and bursitis-like subacromial abnormalities were determined.Results. Residual defects or retears were detected in three (21%) and bursitis-like abnormalities in 14 (100%) of the 14 asymptomatic patients. Fifteen (47%) residual defects or retears and 31 (97%) bursitis-like abnormalities were diagnosed in the 32 patients with residual symptoms. The size of the residual defects/retears was significantly smaller in the asymptomatic group (mean 8 mm, range 6-11 mm) than in the symptomatic group (mean 32 mm, range 7-50 mm) (t-test, P=0.001). The extent of the bursitis-like subacromial abnormalities did not significantly differ (t-test, P>0.05) between asymptomatic (mean 28 x 3 mm) and symptomatic patients (mean 32 x 3 mm).Conclusion. Small residual defects or retears (<1 cm) of the rotator cuff are not necessarily associated with clinical symptoms. Subacromial bursitis-like MR abnormalities are almost always seen after rotator cuff repair even in patients without residual complaints. They may persist for several years after rotator cuff repair and appear to be clinically irrelevant. (orig.)

  10. MR imaging after rotator cuff repair: full-thickness defects and bursitis-like subacromial abnormalities in asymptomatic subjects

    Energy Technology Data Exchange (ETDEWEB)

    Zanetti, M.; Hodler, J. [Dept. of Radiology, University Hospital Balgrist, Zurich (Switzerland); Jost, B.; Gerber, C. [Dept. of Orthopedic Surgery, University Hospital Balgrist, Zurich (Switzerland)

    2000-06-01

    Objective. To determine the prevalence and extent of residual defects or retears and bursitis-like subacromial abnormalities on MR images after rotator cuff repair in asymptomatic subjects, and to define the clinical relevance of these findings.Design and patients. Fourteen completely asymptomatic patients and 32 patients with residual symptoms were investigated 27-53 months (mean 39 months) after open transosseous reinsertion of the rotator cuff. Coronal T2-weighted turbo spin-echo and turbo STIR or T2-weighted fat-suppressed MR images were obtained. The prevalence and extent of residual defects or retears of the rotator cuff and bursitis-like subacromial abnormalities were determined.Results. Residual defects or retears were detected in three (21%) and bursitis-like abnormalities in 14 (100%) of the 14 asymptomatic patients. Fifteen (47%) residual defects or retears and 31 (97%) bursitis-like abnormalities were diagnosed in the 32 patients with residual symptoms. The size of the residual defects/retears was significantly smaller in the asymptomatic group (mean 8 mm, range 6-11 mm) than in the symptomatic group (mean 32 mm, range 7-50 mm) (t-test, P=0.001). The extent of the bursitis-like subacromial abnormalities did not significantly differ (t-test, P>0.05) between asymptomatic (mean 28 x 3 mm) and symptomatic patients (mean 32 x 3 mm).Conclusion. Small residual defects or retears (<1 cm) of the rotator cuff are not necessarily associated with clinical symptoms. Subacromial bursitis-like MR abnormalities are almost always seen after rotator cuff repair even in patients without residual complaints. They may persist for several years after rotator cuff repair and appear to be clinically irrelevant. (orig.)

  11. The reliability of three-dimensional scapular attitudes in healthy people and people with shoulder impingement syndrome

    Directory of Open Access Journals (Sweden)

    Hébert Luc J

    2007-06-01

    Full Text Available Abstract Background Abnormal scapular displacements during arm elevation have been observed in people with shoulder impingement syndrome. These abnormal scapular displacements were evaluated using different methods and instruments allowing a 3-dimensional representation of the scapular kinematics. The validity and the intrasession reliability have been shown for the majority of these methods for healthy people. However, the intersession reliability on healthy people and people with impaired shoulders is not well documented. This measurement property needs to be assessed before using such methods in longitudinal comparative studies. The objective of this study is to evaluate the intra and intersession reliability of 3-dimensional scapular attitudes measured at different arm positions in healthy people and to explore the same measurement properties in people with shoulder impingement syndrome using the Optotrak Probing System. Methods Three-dimensional scapular attitudes were measured twice (test and retest interspaced by one week on fifteen healthy subjects (mean age 37.3 years and eight subjects with subacromial shoulder impingement syndrome (mean age 46.1 years in three arm positions (arm at rest, 70° of humerothoracic flexion and 90° of humerothoracic abduction using the Optotrak Probing System. Two different methods of calculation of 3-dimensional scapular attitudes were used: relative to the position of the scapula at rest and relative to the trunk. Intraclass correlation coefficient (ICC and standard error of measure (SEM were used to estimate intra and intersession reliability. Results For both groups, the reliability of the three-dimensional scapular attitudes for elevation positions was very good during the same session (ICCs from 0.84 to 0.99; SEM from 0.6° to 1.9° and good to very good between sessions (ICCs from 0.62 to 0.97; SEM from 1.2° to 4.2° when using the method of calculation relative to the trunk. Higher levels of

  12. Radiologic analysis of femoral acetabular impingement: from radiography to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Dwek, Jerry R. [University of California at San Diego, Department of Radiology, Rady Children' s Hospital and Health Center, San Diego, CA (United States); San Diego Imaging, San Diego, CA (United States); Monazzam, Shafagh [Rady Children' s Hospital and Health Center, Department of Orthopedics, San Diego, CA (United States); Chung, Christine B. [University of California at San Diego, Department of Radiology, San Diego, CA (United States)

    2013-03-15

    Femoral acetabular impingement is a set of morphologic abnormalities that are considered to be a major cause of degenerative disease in the hip joint. Early changes are already present in adolescence when it is the pediatric radiologist who must assess current damage with the aim of averting progression to more severe and debilitating osteoarthritis. A multimodality approach is used for diagnosis, that includes conventional radiography and CT to assess the osseous structures. MR arthrography is the primary advanced imaging modality for assessment of morphologic changes as well as injuries of the labrum and articular cartilage. Details of radiologic imaging are offered to guide the radiologist and provide an avenue for the accurate description of the osseous and articular alterations and injury. (orig.)

  13. Blood Glucose Levels in Diabetic Patients Following Corticosteroid Injections into the Subacromial Space of the Shoulder.

    Science.gov (United States)

    Aleem, Alexander W; Syed, Usman Ali M; Nicholson, Thema; Getz, Charles L; Namdari, Surena; Beredjiklian, Pedro K; Abboud, Joseph A

    2017-09-01

    Corticosteroid injections are used to treat a variety of orthopedic conditions with the goal of decreasing pain and inflammation. Administration of systemic or local corticosteroids risks temporarily increasing blood glucose levels, especially diabetic patients. The purpose of this study is to quantify the effects of corticosteroid injections on blood glucose levels in diabetic patients with shoulder pathology. Diabetic patients who regularly monitored their blood glucose levels and were indicated for a subacromial corticosteroid injection were included in this prospective investigation. The typical normal morning fasting glucose and most recent hemoglobin A1c level was recorded for each patient. After injection, patients were contacted daily to confirm their fasting morning glucose level for 10 days post-injection. Seventeen consecutive patients were enrolled. Patients with hemoglobin A1c of patients' glucose levels returned to near baseline levels around post-injection day 8, while poorly controlled patients levels remained elevated. Similarly, insulin-dependent diabetic patients had an average increase in fasting glucose level of 99 mg/dL versus 50 mg/dL in non-insulin-dependent diabetic patients ( P patients with well-controlled diabetes experience smaller elevations and faster return to baseline glucose levels than patients with poor control. Insulin dependent diabetics experienced similar findings as patients with poor control. Future studies are needed to evaluate dosing to optimize the risks of blood glucose elevation while maintaining therapeutic benefit.

  14. Performance of jet impingement in unglazed air collectors

    Energy Technology Data Exchange (ETDEWEB)

    Belusko, M.; Saman, W.; Bruno, F. [Institute for Sustainable Systems and Technologies, University of South Australia, Mawson Lakes Boulevard, Mawson Lakes, SA 5095 (Australia)

    2008-05-15

    Jet impingement is effective at improving the heat transfer between air and a heated surface. Studies have shown that jet impingement can marginally improve the thermal efficiency of a glazed collector. However, little attention has been placed on applying jet impingement to an unglazed solar air collector. This paper presents a theoretical and experimental investigation identifying the performance characteristics of jet impingement. Overall, jet impingement was able to improve the thermal efficiency of the collector by 21%. An increase in the pressure loss was also measured but found to be small. The flow distribution of jets along the collector was the most significant factor in determining the efficiency. Increasing the hole spacing was found to improve the efficiency. (author)

  15. Sports hernia and femoroacetabular impingement in athletes: A systematic review.

    Science.gov (United States)

    Munegato, Daniele; Bigoni, Marco; Gridavilla, Giulia; Olmi, Stefano; Cesana, Giovanni; Zatti, Giovanni

    2015-09-16

    To investigate the association between sports hernias and femoroacetabular impingement (FAI) in athletes. PubMed, MEDLINE, CINAHL, Embase, Cochrane Controlled Trials Register, and Google Scholar databases were electronically searched for articles relating to sports hernia, athletic pubalgia, groin pain, long-standing adductor-related groin pain, Gilmore groin, adductor pain syndrome, and FAI. The initial search identified 196 studies, of which only articles reporting on the association of sports hernia and FAI or laparoscopic treatment of sports hernia were selected for systematic review. Finally, 24 studies were reviewed to evaluate the prevalence of FAI in cases of sports hernia and examine treatment outcomes and evidence for a common underlying pathogenic mechanism. FAI has been reported in as few as 12% to as high as 94% of patients with sports hernias, athletic pubalgia or adductor-related groin pain. Cam-type impingement is proposed to lead to increased symphyseal motion with overload on the surrounding extra-articular structures and muscle, which can result in the development of sports hernia and athletic pubalgia. Laparoscopic repair of sports hernias, via either the transabdominal preperitoneal or extraperitoneal approach, has a high success rate and earlier recovery of full sports activity compared to open surgery or conservative treatment. For patients with FAI and sports hernia, the surgical management of both pathologies is more effective than sports pubalgia treatment or hip arthroscopy alone (89% vs 33% of cases). As sports hernias and FAI are typically treated by general and orthopedic surgeons, respectively, a multidisciplinary approach for diagnosis and treatment is recommended for optimal treatment of patients with these injuries. The restriction in range of motion due to FAI likely contributes to sports hernias; therefore, surgical treatment of both pathologies represents an optimal therapy.

  16. The Natural History of Femoroacetabular Impingement

    Directory of Open Access Journals (Sweden)

    Benjamin D. Kuhns

    2015-11-01

    Full Text Available Femoroacetabular impingement (FAI is a clinical syndrome resulting from abnormal hip joint morphology and is a common cause of hip pain in young adults. FAI has been posited as a precursor to hip osteoarthritis, however, conflicting evidence exists and the true natural history of the disease is unclear. The purpose of this article is to review the current understanding of how FAI damages the hip joint by highlighting its pathomechanics and etiology. We then review the current evidence relating FAI to osteoarthritis. Lastly, we will discuss the potential of hip preservation surgery to alter the natural history of FAI, reduce the risk of developing osteoarthritis and the need for future arthroplasty.

  17. Cam and Pincer Type of Femoroacetabular Impingement.

    Science.gov (United States)

    Ersoy, Hale; Trane, R Nicholas; Pomeranz, Stephen J

    Femoroacetabular impingement (FAI) has gained considerable attention for the past 20 years and has been accepted as a predisposing factor for early osteoarthritis in young patients, particularly in the population participating in sports. Patients with FAI typically present with deep, intermittent groin discomfort during or after activities involving repetitive or persistent hip flexion. Symptomatic improvement can be achieved from arthroscopic debridement of unstable cartilage flaps, shaving of cartilage irregularities, and surgical correction of deformity of the femoral head\\endash neck junction. Early and correct diagnosis of FAI has paramount importance for appropriate and timely management of the disorder before the development of osteoarthritis. Magnetic resonance (MR) imaging offers a noninvasive means of assessing the degree of damage to cartilage and adjacent labrum and bone and also evaluating the effectiveness of treatment. This article describes the morphologic types of FAI with emphasis on MR findings.

  18. Characteristics of steam jet impingement on annulus

    International Nuclear Information System (INIS)

    Yoon, Sang H.; Kim, Won J.; Suh, Kune Y.; Song, Chul H.

    2004-01-01

    The steam jet impingement occurs when the steam through the cold leg from the steam generator strikes the inner reactor barrel during the reflood phase of a loss-of-coolant accident (LOCA), which is a characteristic behavior for the APR1400 (Advanced Power Reactor 1400 MWe). In the cold leg break LOCA, the steam and water flows in the downcomer are truly multidimensional. The azimuthal velocity distribution of the steam flow has an important bearing on the thermal hydraulic phenomena such as the emergency coolant water direct bypass, sweepout, steam condensation, and so forth. The investigation of jet flow is required to determine the steam path and momentum reduction rate after the impingement. For the observation of the steam behavior near the break, the computational fluid dynamic (CFD) analysis has been carried out using CFX5.6. The flow visualization and analysis demonstrate the velocity profiles of the steam flow in the annulus region for the same boundary conditions. Pursuant to the CFD results, the micro-Pitot tubes were positioned at varying angles, and corrected for their sensitivity. The experiments were carried out to directly measure the pressure differential and to visualize the flow utilizing a smoke injection method. Results from this study are slated to be applied to MARS, which is a thermal hydraulic system code for the best-estimate analysis. The current one- or two-dimensional analysis in MARS was known to distort the local flow behavior. To enhance prediction capability of MARS, it is necessary to inspect the steam path in the break flow and mechanically simulate the momentum variation. The present experimental and analytical results can locally be applied to developing the engineering models of specific and essential phenomena. (author)

  19. Impinging Water Droplets on Inclined Glass Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Armijo, Kenneth Miguel [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Lance, Blake [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ho, Clifford K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-09-01

    Multiphase computational models and tests of falling water droplets on inclined glass surfaces were developed to investigate the physics of impingement and potential of these droplets to self-clean glass surfaces for photovoltaic modules and heliostats. A multiphase volume-of-fluid model was developed in ANSYS Fluent to simulate the impinging droplets. The simulations considered different droplet sizes (1 mm and 3 mm), tilt angles (0°, 10°, and 45°), droplet velocities (1 m/s and 3 m/s), and wetting characteristics (wetting=47° contact angle and non-wetting = 93° contact angle). Results showed that the spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) decreased with increasing inclination angle due to the reduced normal force on the surface. The hydrophilic surface yielded greater spread factors than the hydrophobic surface in all cases. With regard to impact forces, the greater surface tilt angles yielded lower normal forces, but higher shear forces. Experiments showed that the experimentally observed spread factor (maximum droplet diameter during impact divided by the initial droplet diameter) was significantly larger than the simulated spread factor. Observed spread factors were on the order of 5 - 6 for droplet velocities of ~3 m/s, whereas the simulated spread factors were on the order of 2. Droplets were observed to be mobile following impact only for the cases with 45° tilt angle, which matched the simulations. An interesting phenomenon that was observed was that shortly after being released from the nozzle, the water droplet oscillated (like a trampoline) due to the "snapback" caused by the surface tension of the water droplet being released from the nozzle. This oscillation impacted the velocity immediately after the release. Future work should evaluate the impact of parameters such as tilt angle and surface wettability on the impact of particle/soiling uptake and removal to investigate ways that

  20. Effectiveness of telerehabilitation programme following surgery in shoulder impingement syndrome (SIS): study protocol for a randomized controlled non-inferiority trial.

    Science.gov (United States)

    Pastora-Bernal, Jose-Manuel; Martín-Valero, Rocío; Barón-López, Francisco Javier; García-Gómez, Oscar

    2017-02-23

    Shoulder pain is common in society, with high prevalence in the general population. Shoulder impingement syndrome (SIS) is the most frequent cause. Patients suffer pain, muscle weakness and loss of movement in the affected joint. Initial treatment is predominantly conservative. The surgical option has high success rates and is often used when conservative strategy fails. Traditional physiotherapy and post-operative exercises are needed for the recovery of joint range, muscle strength, stability and functionality. Telerehabilitation programmes have shown positive results in some orthopaedic conditions after surgery. Customized telerehabilitation intervention programmes should be developed to recover shoulder function after SIS surgery. The objective of this study is to evaluate the feasibility and effectiveness of a telerehabilitation intervention compared with usual care in patients after subacromial decompression surgery. We will compare an intervention group receiving videoconferences and a telerehabilitation programme to a control group receiving traditional physiotherapy intervention in a single-blind, randomized controlled non-inferiority trial study design. Through this study, we will further develop our preliminary data set and practical experience with the telerehabilitation programmes to evaluate their effectiveness and compare this with traditional intervention. We will also explore patient satisfaction and cost-effectiveness. Patient enrolment is ongoing. ClinicalTrials.gov, NCT02909920 . 14 September 2016.

  1. Experimental and Computational Study of Underexpanded Jet Impingement Heat Transfer

    Science.gov (United States)

    Rufer, Shann J.; Nowak, Robert J.; Daryabeigi, Kamran; Picetti, Donald

    2009-01-01

    An experiment was performed to assess CFD modeling of a hypersonic-vehicle breach, boundary-layer flow ingestion and internal surface impingement. Tests were conducted in the NASA Langley Research Center 31-Inch Mach 10 Tunnel. Four simulated breaches were tested and impingement heat flux data was obtained for each case using both phosphor thermography and thin film gages on targets placed inside the model. A separate target was used to measure the surface pressure distribution. The measured jet impingement width and peak location are in good agreement with CFD analysis.

  2. MR imaging of nerve root impingement in the lumbar spine

    International Nuclear Information System (INIS)

    Teresi, L.M.; Bradley, W.G. Jr.; Bloze, A.E.; Davis, S.J.; Amster, J.; Berger, P.E.

    1990-01-01

    This paper determines the relationship between MR imaging findings of nerve root impingement, presenting symptoms, and physical examination findings, and physiologic data (DSEP and EMG) in a population of patients presented with classic radicular symptoms. Fifty-eight patients presenting with classic radicular pain were studied with MR imaging, DSER, and EMG, MR imaging was performed with a GE Signa imaging system with use of T1- and T2-weighted sequences and 5-mm-thick sections. Nerve root impingement in the subarticular recess (the root exiting the next lowest level) was distinguished from nerve root impingement in the superior intervertebral foramen (the root exiting the same level)

  3. Biological evaluation of devices used for reducing entrainment and impingement losses at thermal power plants

    International Nuclear Information System (INIS)

    Cada, G.F.; Szluha, A.T.

    1978-01-01

    A preliminary survey of fish protection devices either in use or proposed for water intake structures was conducted for the purpose of assessing their potential for reducing impingement and entrainment. All the designs examined can be divided into two basic categories: behavioral screening systems and physical screening systems. The behavioral screening devices rely upon the ability of fish to sense artificial stimuli and respond by swimming away from hazardous areas. These systems are of little or no value in protecting planktonic fish eggs, larvae, and disoriented, heat-shocked, or lethargic adult fishes. Many of the physical screening devices, on the other hand, require the impingement of organisms against a screen before they can be removed from the intake system, thus subjecting survival. Some of the designs incorporate both behavioral and physical sceening concepts. Six devices were selected for further consideration based on their potential or demonstrated effectiveness in reducing impingement and entrainment losses at a variety of intake situations. The structures evaluated were modified vertical traveling screens, louvers, angled vertical traveling screens, horizontal traveling screens, center-flow screens, and wedge-wire screens. Since some of these intake structures represent new concepts, few laboratory or in situ biological studies have been carried out. For others, actual reductions in fish losses have been demonstrated. The design features and status of biological testing is discussed for each device, and an evaluation of their fish protection potential is presented

  4. IMPINGEMENT-SYNDROME OF PERONEUS BREVIS TENDON AFTER CALCANEAL FRACTURES (MORPHOLOGICAL ASPECTS

    Directory of Open Access Journals (Sweden)

    N. S. Konovalchuk

    2017-01-01

    Full Text Available Background. One of the main causes of pain in patients with consequences of calcaneal fractures is the lateral impingement syndrome. This term means lateral displacement of outer calcaneal wall at the moment of fracture, narrowing of anatomical space under the lateral malleolus and compression of soft tissues in this region, including tendons of short and long peroneal muscles. This leads to chronic traumatization of tendons, alteration of their normal tracking and development of tendinitis and tenosynovitis. At this moment there are no articles in foreign or Russian literature describing how prolonged traumatization influences the internal structure of the tendons. The purpose of this study was to evaluate the morphological changes in structure of peroneus brevis tendon after different duration of compression between outer wall of calcaneus and the tip of the lateral malleolus in patients with calcaneal malunion.Materials and methods. Fifteen patients with calcaneal malunion and lateral impingement syndrome were treated operatively between 2016 and 2017. To confirm the lateral impingement syndrome, the authors performed clinical examination and AP x-rays of ankle joint. Two peroneus brevis tendon specimens were obtained intraoperatively in each of 15 patients: one specimen from compressed and one from non-compressed area. Obtained specimens were histologically examined according to standard protocol.Results. Microscopically all specimens showed separation of collagen bundles with loose connective tissue degeneration, increase of vascularization and inflammation. The degree of these changes differed according to the compression duration. This allowed us to analyze the dynamics of these changes.Conclusion. The morphological changes in structure of peroneus brevis tendon during the compression between outer wall of calcaneus and the tip of the lateral malleolus correspond with dynamics of common pathologic reactions. Early stages showed signs of

  5. Trochanteric impingement: is it a source of pain after THR?

    Directory of Open Access Journals (Sweden)

    Mark J. Isaacson, DO

    2015-09-01

    Full Text Available While uncommon, trochanteric-pelvic impingement may lead to significant lateral hip pain. We defined “impingement distance” as the radiographic distance from the medial aspect of the greater trochanter and the corresponding lateral edge of the acetabular bone or component and compared this to the contralateral normal hip. We present two painful total hip replacement (THR cases, each featuring a patient with severe lateral hip pain when walking and sitting. Both patients had diminished femoral offset and trochanteric-pelvic clearance, compared to the contralateral normal hip. The impingement distance was increased an average of 10 mm with the exchange to a longer femoral head. Both patients had immediate and complete pain relief with operative treatment to increase the impingement distance.

  6. Surgical hip dislocation for treatment of cam femoroacetabular impingement

    Directory of Open Access Journals (Sweden)

    Milind M Chaudhary

    2015-01-01

    Conclusion: Cam femoroacetabular Impingement causing pain and limitation of hip movements was treated by open osteochondroplasty after surgical hip dislocation. This reduced pain, improved hip motion and gave good to excellent results in the short term.

  7. Impact of impingement on the Hudson River white perch population

    International Nuclear Information System (INIS)

    Barnthouse, L.W.; Van Winkle, W.

    1980-01-01

    The impact of power plant impingement on the 1974 and 1975 year classes of the Hudson River white perch population is assessed using a simple model derived from Ricker's theory of fisheries dynamics. The impact of impingement is expressed in the model as the conditional mortality rate, rather than as the more commonly used exploitation rate. Since the calculated impact is sensitive to errors in the estimation of population size and total mortality, ranges of probable values of these quantities are used to compute upper and lower bounds on the fractional reduction in abundance of each year class. Best estimates of abundance and mortality are used to compute the conditional impingement mortality rate separately for each plant and month. The results are used to assess the relative impacts of white perch impingement at six Hudson River power plants and to identify the seasons during which the impact is highest

  8. Open and Arthroscopic Surgical Treatment of Femoroacetabular Impingement

    Directory of Open Access Journals (Sweden)

    Benjamin D. Kuhns

    2015-12-01

    Full Text Available Femoroacetabular impingement (FAI is a common cause of hip pain, and when indicated, can be successfully managed through open surgery or hip arthroscopy. The goal of this review is to describe the different approaches to the surgical treatment of FAI. We present the indications, surgical technique, rehabilitation, and complications associated with (1 open hip dislocation, (2 reverse peri-acetabular osteotomy, (3 the direct anterior mini-open approach, and (4 arthroscopic surgery for femoroacetabular impingement.

  9. Supersonic impinging jet noise reduction using a hybrid control technique

    Science.gov (United States)

    Wiley, Alex; Kumar, Rajan

    2015-07-01

    Control of the highly resonant flowfield associated with supersonic impinging jet has been experimentally investigated. Measurements were made in the supersonic impinging jet facility at the Florida State University for a Mach 1.5 ideally expanded jet. Measurements included unsteady pressures on a surface plate near the nozzle exit, acoustics in the nearfield and beneath the impingement plane, and velocity field using particle image velocimetry. Both passive control using porous surface and active control with high momentum microjet injection are effective in reducing nearfield noise and flow unsteadiness over a range of geometrical parameters; however, the type of noise reduction achieved by the two techniques is different. The passive control reduces broadband noise whereas microjet injection attenuates high amplitude impinging tones. The hybrid control, a combination of two control methods, reduces both broadband and high amplitude impinging tones and surprisingly its effectiveness is more that the additive effect of the two control techniques. The flow field measurements show that with hybrid control the impinging jet is stabilized and the turbulence quantities such as streamwise turbulence intensity, transverse turbulence intensity and turbulent shear stress are significantly reduced.

  10. Investigation of impingement attack mechanism of copper alloy condenser tubes

    Energy Technology Data Exchange (ETDEWEB)

    Fukumura, Takuya; Nakajima, Nobuo; Arioka, Koji; Totsuka, Nobuo; Nakagawa, Tomokazu [Institute of Nuclear Safety System Inc., Mihama, Fukui (Japan)

    2001-09-01

    In order to investigate generation and growth mechanisms of impingement attacks of sea water against copper alloy condenser tubes used in condensers of nuclear power plants, we took out condenser tubes from actual condensers, cut them into several pieces and carried out several material tests mainly for impinged spots. In addition water flow inside of a pit was analyzed. From the results of the investigation, it was found that all of impingement attacks were found in the marks left by sessile organisms and none were found in downstream of the marks as frequently proposed so far. At the pits generated inside the marks, iron coating was striped and zinc content was deficient in some cases. Combining these data and the result of flow analysis, we considered the following mechanism of the impingement attacks: sessile organisms clinging to the surface of the condenser tube and growth, occlusion of the tube, extinction and decomposition of sessile organisms, pollution corrosion under the organisms and cavity formation, occlusion removal by the cleaning, generation of impingement attacks by flow collision inside the cavity, growth of the impingement attacks. (author)

  11. Impact of entrainment and impingement on fish populations in the Hudson River Estuary. Volume II. Impingement impact analyses, evaluations of alternative screening devices, and critiques of utility testimony relating to density-dependent growth, the age-composition of the striped bass spawning stock, and the LMS real-time life cycle model

    International Nuclear Information System (INIS)

    Barnthouse, L.W.; Van Winkle, W.; Golumbek, J.; Cada, G.F.; Goodyear, C.P.; Christensen, S.W.; Cannon, J.B.; Lee, D.W.

    1982-04-01

    This volume includes a series of four exhibits relating to impacts of impingement on fish populations, together with a collection of critical evaluations of testimony prepared for the utilities by their consultants. The first exhibit is a quantitative evaluation of four sources of bias (collection efficiency, reimpingement, impingement on inoperative screens, and impingement survival) affecting estimates of the number of fish killed at Hudson River power plants. The two following exhibits contain, respectively, a detailed assessment of the impact of impingement on the Hudson River white perch population and estimates of conditional impingement mortality rates for seven Hudson River fish populations. The fourth exhibit is an evaluation of the engineering feasibility and potential biological effectiveness of several types of modified intake structures proposed as alternatives to cooling towers for reducing impingement impacts. The remainder of Volume II consists of critical evaluations of the utilities' empirical evidence for the existence of density-dependent growth in young-of-the-year striped bass and white perch, of their estimate of the age-composition of the striped bass spawning stock in the Hudson River, and of their use of the Lawler, Matusky, and Skelly (LMS) Real-Time Life Cycle Model to estimate the impact of entrainment and impingement on the Hudson River striped bass population

  12. Buoyancy effects laminar slot jet impinging on a surface with constant heat flux

    International Nuclear Information System (INIS)

    Shokouhmand, H.; Esfahanian, V.; Masoodi, R.

    2004-01-01

    The two-dimensional laminar air jet issuing from a nozzle of half which terminates at height above a flat plate normal to the jet is numerically on the flow and thermal structure of the region near impingement. The impinging surface is maintained at a constant heat flux condition. The full Navier-Stocks and energy equations are solved by a finite difference method to evaluate the velocity profiles and temperature distribution. The governing parameters and their ranges are: Reynolds number Re, 10-50, Grashof number Gr, 0-50, Richardson number Ri=Gr/ Re 2 , Non dimensional nozzle height H,2-3. Results of the free streamline, local friction factor and heat transfer coefficient are graphically presented. It is found that enhancement of the heat transfer rate is substantial for high Richardson number conditions. Although the laminar jet impingement for isothermal condition has been already studied, however the constant heat flux has not been studied enough. the present paper will analyze a low velocity air jet, Which can be used for cooling of a simulated electronics package

  13. Arthroscopy Up to Date: Hip Femoroacetabular Impingement.

    Science.gov (United States)

    Khan, Moin; Habib, Anthony; de Sa, Darren; Larson, Christopher M; Kelly, Bryan T; Bhandari, Mohit; Ayeni, Olufemi R; Bedi, Asheesh

    2016-01-01

    To provide a comprehensive review and summary of the research published in Arthroscopy: The Journal of Arthroscopic and Related Surgery and The American Journal of Sports Medicine (AJSM) related to hip arthroscopy for femoroacetabular impingement (FAI). A comprehensive review was conducted in duplicate of Arthroscopy and AJSM from February 2012 to February 2015 for all articles related to FAI, and a quality assessment was completed for all included studies. Clinical outcomes were dichotomized into short-term (Arthroscopy and 44 studies in AJSM, primarily from North America (78.8%), that predominantly assessed clinical outcomes after arthroscopic hip surgery (46.1%). Seventy-one percent of Arthroscopy studies and 20.5% of AJSM studies were Level IV evidence. The modified Harris Hip Score (mHHS) was used by 81.5% of included studies. Pooled weighted mean mHHS values after arthroscopic surgery for FAI showed improvements at the midterm from 60.5 points (range, 56.6 to 83.6 points) to 80.5 points (range, 72.1 to 98.0 points) out of a possible 100 points. Pooled weighted outcomes for labral repair showed mean mHHS improvements from 63.8 points (range, 62.5 to 69.0 points) preoperatively to 86.9 points (range, 85.5 to 89.9 points) up to 24 months postoperatively. This comprehensive review of research published in Arthroscopy and AJSM over the past 3 years identified a number of key findings. Arthroscopic intervention results in improvements in functional outcomes at both the short-term and midterm for patients with symptomatic FAI in the absence of significant existing degenerative changes. Labral repair may result in improvements over labral debridement. The most commonly used outcome score was the mHHS for objective assessment of surgical success. There is a need for continued focus on improvement of methodologic quality and reporting of research pertaining to FAI. Level IV, systematic review of Level IV studies. Copyright © 2016 Arthroscopy Association of North

  14. Atomization of Impinging Droplets on Superheated Superhydrophobic Surfaces

    Science.gov (United States)

    Emerson, Preston; Crockett, Julie; Maynes, Daniel

    2017-11-01

    Water droplets impinging smooth superheated surfaces may be characterized by dynamic vapor bubbles rising to the surface, popping, and causing a spray of tiny droplets to erupt from the droplet. This spray is called secondary atomization. Here, atomization is quantified experimentally for water droplets impinging superheated superhydrophobic surfaces. Smooth hydrophobic and superhydrophobic surfaces with varying rib and post microstructuring were explored. Each surface was placed on an aluminum heating block, and impingement events were captured with a high speed camera at 3000 fps. For consistency among tests, all events were normalized by the maximum atomization found over a range of temperatures on a smooth hydrophobic surface. An estimate of the level of atomization during an impingement event was created by quantifying the volume of fluid present in the atomization spray. Droplet diameter and Weber number were held constant, and atomization was found for a range of temperatures through the lifetime of the impinging droplet. The Leidenfrost temperature was also determined and defined to be the lowest temperature at which atomization ceases to occur. Both atomization and Leidenfrost temperature increase with decreasing pitch (distance between microstructures).

  15. Shear layer characteristics of supersonic free and impinging jets

    Science.gov (United States)

    Davis, T. B.; Kumar, R.

    2015-09-01

    The initial shear layer characteristics of a jet play an important role in the initiation and development of instabilities and hence radiated noise. Particle image velocimetry has been utilized to study the initial shear layer development of supersonic free and impinging jets. Microjet control employed to reduce flow unsteadiness and jet noise appears to affect the development of the shear layer, particularly near the nozzle exit. Velocity field measurements near the nozzle exit show that the initially thin, uncontrolled shear layer develops at a constant rate while microjet control is characterized by a rapid nonlinear thickening that asymptotes downstream. The shear layer linear growth rate with microjet control, in both the free and the impinging jet, is diminished. In addition, the thickened shear layer with control leads to a reduction in azimuthal vorticity for both free and impinging jets. Linear stability theory is used to compute unstable growth rates and convection velocities of the resultant velocity profiles. The results show that while the convection velocity is largely unaffected, the unstable growth rates are significantly reduced over all frequencies with microjet injection. For the case of the impinging jet, microjet control leads to near elimination of the impingement tones and an appreciable reduction in broadband levels. Similarly, for the free jet, significant reduction in overall sound pressure levels in the peak radiation direction is observed.

  16. Thermal-hydraulic performance of convective boiling jet array impingement

    International Nuclear Information System (INIS)

    Jenkins, R; De Brún, C; Kempers, R; Lupoi, R; Robinson, A J

    2016-01-01

    Jet impingement boiling is investigated with regard to heat transfer and pressure drop performance using a novel laser sintered 3D printed jet impingement manifold design. Water was the working fluid at atmospheric pressure with inlet subcooling of 7 o C. The convective boiling performance of the impinging jet system was investigated for a flat copper target surface for 2700≤Re≤5400. The results indicate that the heat transfer performance of the impinging jet is independent of Reynolds number for fully developed boiling. Also, the investigation of nozzle to plate spacing shows that low spacing delays the onset of nucleate boiling causing a superheat overshoot that is not observed with larger gaps. However, no sensitivity to the gap spacing was measured once boiling was fully developed. The assessment of the pressure drop performance showed that the design effectively transfers heat with low pumping power requirements. In particular, owing to the insensitivity of the heat transfer to flow rate during fully developed boiling, the coefficient of performance of jet impingement boiling in the fully developed boiling regime deteriorates with increased flow rate due to the increase in pumping power flux. (paper)

  17. ARTHROSCOPIC TREATMENT OF ANTERIOR IMPINGEMENT IN THE ANKLE

    Directory of Open Access Journals (Sweden)

    Martin Mikek

    2004-12-01

    Full Text Available Background. Anterior soft tissue impingement is a common cause of chronic pain in the ankle. The preferred method of operative treatment is an arthroscopic excision of hypertrophic fibrous and synovial tissue in the anterior part of the ankle joint.Methods. We present the results of arthroscopic treatment of anterior ankle impingement in group of 14 patients.Results. Subjective improvement after the procedure was observed in all patients and 13 of them (93% were without any symptoms after the operation. One patient reported of intermittent pain, especially when walking on uneven grounds.Conclusions. We conclude that arthroscopic excision of hypertrophic synovial tissue in the anterior part of the ankle which causes the symptoms of impingement is a minimally invasive procedure that is both safe and reliable. When used for appropriate indications, an improvement can be expected in over 90% of patients.

  18. The jet impingement phase of molten core-concrete interactions

    International Nuclear Information System (INIS)

    Sienicki, J.J.; Spencer, B.W.

    1986-01-01

    Scoping calculations have been carried out demonstrating that a significant and abrupt reduction in the corium temperature may be realized when molten corium drains as a jet from a localized breach in the RPV lower head to impinge upon the concrete basemat. The temperature decrease may range from a value of ∼170 K (∼140 K) for limestone (basaltic) aggregate concrete to a value approaching the initial corium superheat depending upon whether the forced convection impingement heat flux is assumed to be controlled by either thermal conduction across a slag film layer or the temperature boundary condition represented by a corium crust. The magnitude of the temperature reduction remains significant as the initial corium temperature, impinging corium mass, and initial localized breach size are varied over their range of potential values

  19. Analysis of impingement impacts on Hudson River fish populations

    International Nuclear Information System (INIS)

    Barnthouse, L.W.; van Winkle, W.

    1988-01-01

    Impacts of impingement, expressed as reductions in year-class abundance, were calculated for six Hudson River fish populations. Estimates were made for the 1974 and 1975 year classes of white perch, striped bass, Atlantic tomcod, and American shad, and the 1974 year classes of alewife and blueback herring. The maximum estimated reductions in year-class abundance were less than 5% for all year classes except the 1974 and 1975 white perch year classes and the 1974 striped bass year class. Only for white perch were the estimates greater than 10% per year. For striped bass, the 146,000 fish from the 1974 year class that were killed by impingement could have produced 12,000-16,000 5-year-old fish or 270-300 10-year-olds. Also estimated were the reductions in mortality that could have been achieved had closed-cycle cooling systems been installed at one or more of three power plants (Bowline point, Indian Point, and Roseton) and had the screen-wash systems at Bowline Point and Indian Point been modified to improve the survival of impinged fish. Closed-cycle cooling at all three plants would have reduced impingement impacts on white perch, striped bass, and Atlantic tomcod by 75% or more; installation of closed-cycle cooling at Indian Point alone would have reduced impingement impacts on white perch and Atlantic tomcod by 50%-80%. Modified traveling screens would have been less effective than closed-cycle cooling, but still would have reduced impingement impacts on white perch by roughly 20%. 23 refs., 1 fig., 3 tabs

  20. Muscle Activation Pattern during Selected Functional Task in Shoulder Impingement Syndrome vs. Normal Subjects

    Directory of Open Access Journals (Sweden)

    Mehrnaz Kajbaf-Vala

    2009-10-01

    Conclusion: Changes in muscle recruitment pattern are task dependent that this may be due to direction of movement and axial compression loading in subacromial space. Among all selected exercises in D2E (Diagonal 2 Extension minimum changes and in tripod maximum changes (in time domain were seen.

  1. Ultrasound-Guided Application of Percutaneous Electrolysis as an Adjunct to Exercise and Manual Therapy for Subacromial Pain Syndrome: a Randomized Clinical Trial.

    Science.gov (United States)

    de-Miguel-Valtierra, Lorena; Salom-Moreno, Jaime; Fernández-de-Las-Peñas, César; Cleland, Joshua A; Arias-Buría, José L

    2018-05-16

    This randomized clinical trial compared the effects of adding US-guided percutaneous electrolysis into a program consisting of manual therapy and exercise on pain, related-disability, function and pressure sensitivity in subacromial pain syndrome. Fifty patients with subacromial pain syndrome were randomized into manual therapy and exercise or percutaneous electrolysis group. All patients received the same manual therapy and exercise program, one session per week for 5 consecutive weeks. Patients assigned to the electrolysis group also received the application of percutaneous electrolysis at each session. The primary outcome was Disabilities of the Arm, Shoulder and Hand (DASH). Secondary outcomes included pain, function (Shoulder Pain and Disability Index-SPADI) pressure pain thresholds (PPTs) and Global Rating of Change (GROC). They were assessed at baseline, post-treatment, and 3, and 6 months after treatment. Both groups showed similar improvements in the primary outcome (DASH) at all follow-ups (P=0.051). Subjects receiving manual therapy, exercise, and percutaneous electrolysis showed significantly greater changes in shoulder pain (P0.91) for shoulder pain and function at 3 and 6 months in favour of the percutaneous electrolysis group. No between-groups differences in PPT were found. The current clinical trial found that the inclusion of US-guided percutaneous electrolysis in combination with manual therapy and exercise resulted in no significant differences for related-disability (DASH) than the application of manual therapy and exercise alone in patients with subacromial pain syndrome. Nevertheless, differences were reported for some secondary outcomes such as shoulder pain and function (SPADI). Whether or not these effects are reliable should be addressed in future studies Perspective This study found that the inclusion of US-guided percutaneous electrolysis into a manual therapy and exercise program resulted in no significant differences for disability

  2. Anterior internal impingement of the shoulder in rugby players and other overhead athletes

    Directory of Open Access Journals (Sweden)

    Siddharth R. Shah, MBBS, MSc Sports Medicine (UK, MRCS-Ed

    2017-04-01

    Conclusion: This series of anterior internal impingement, which we believe is the largest in the literature to date, demonstrates the value of an to assess and successfully treat overhead athletes with anterior impingement syndrome.

  3. Open versus arthroscopic treatment of chronic rotator cuff impingement

    NARCIS (Netherlands)

    Schröder, J.; van Dijk, C. N.; Wielinga, A.; Kerkhoffs, G. M.; Marti, R. K.

    2001-01-01

    We report the results of 238 consecutive patients who underwent in total 261 acromioplasties because of chronic rotator cuff impingement. The procedure was performed either in conventional open technique (80) or arthroscopically (181). Two years (1-10) after the operation 68% of the patients treated

  4. Quantifying cell adhesion through impingement of a controlled microjet

    NARCIS (Netherlands)

    Visser, C.W.; Gielen, Marise V.; Gielen, Marise Vera; Hao, Zhenxia; le Gac, Severine; Lohse, Detlef; Sun, Chao

    2015-01-01

    The impingement of a submerged, liquid jet onto a cell-covered surface allows assessing cell attachment on surfaces in a straightforward and quantitative manner and in real time, yielding valuable information on cell adhesion. However, this approach is insufficiently characterized for reliable and

  5. Calcific tendinitis of the rotator cuff: a randomized controlled trial of ultrasound-guided needling and lavage versus subacromial corticosteroids.

    Science.gov (United States)

    de Witte, Pieter Bas; Selten, Jasmijn W; Navas, Ana; Nagels, Jochem; Visser, Cornelis P J; Nelissen, Rob G H H; Reijnierse, Monique

    2013-07-01

    Calcific tendinitis of the rotator cuff (RCCT) is frequently diagnosed in patients with shoulder pain, but there is no consensus on its treatment. To compare 2 regularly applied RCCT treatments: ultrasound (US)-guided needling and lavage (barbotage) combined with a US-guided corticosteroid injection in the subacromial bursa (subacromial bursa injection [SAI]) (group 1) versus an isolated SAI (group 2). Randomized controlled trial; Level of evidence, 1. Patients were randomly assigned to the 2 groups. Shoulder function was assessed before treatment and at regular follow-up intervals (6 weeks and 3, 6, and 12 months) using the Constant shoulder score (CS, primary outcome), the Western Ontario Rotator Cuff Index (WORC), and the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH). Additionally, calcification location, size, and Gärtner classification were assessed on radiographs. Results were analyzed using the t test, linear regression, and a mixed model for repeated measures. This study included 48 patients (25 female, 52.1%; mean age, 52.0 ± 7.3 years; 23 patients in group 1) with a mean baseline CS of 68.7 ± 11.9. No patients were lost to follow-up. Four patients in group 1 and 11 in group 2 (P = .06) had an additional barbotage procedure or surgery during the follow-up period because of persisting symptoms and no resorption. At 1-year follow-up, the mean CS in group 1 was 86.0 (95% CI, 80.3-91.6) versus 73.9 (95% CI, 67.7-80.1) in group 2 (P = .005). The mean calcification size decreased by 11.6 ± 6.4 mm in group 1 and 5.1 ± 5.7 mm in group 2 (P = .001). There was total resorption in 13 patients in group 1 and 6 patients in group 2 (P = .07). With regression analyses, correcting for baseline CS and Gärtner type, the mean treatment effect was 20.5 points (P = .05) in favor of barbotage. Follow-up scores were significantly influenced by baseline scores. Results for the DASH and WORC were similar. On average, there was improvement at 1-year follow

  6. Effectiveness of ultrasound-guided injections combined with shoulder exercises in the treatment of subacromial adhesive bursitis.

    Science.gov (United States)

    Gasparre, Giuseppe; Fusaro, Isabella; Galletti, Stefano; Volini, Silvia; Benedetti, Maria Grazia

    2012-05-01

    The aim of this study was to evaluate whether the association of exercises for the shoulder with ultrasound-guided injection into the bursa significantly improves the treatment outcome in adhesive bursitis. Two groups of 35 patients, one treated with ultrasound-guided injection (UGI) and the other one with ultrasound-guided injection and home exercise program (UGI-exercise) for 1 month, were assessed for pain and shoulder function before treatment, 1 and 3 months post-treatment. Fourteen patients in UGI group and 23 patients in the UGI-exercises group were completely free of pain after 1 month (p = 0.031). At 3 months' follow-up, patients in the UGI-exercise group showed a significant improvement with respect to the other group (p = 0.005). No differences were found in function assessment. The UGI combined with shoulder exercises in the treatment of subacromial adhesive bursitis is effective to ensure a more frequent complete pain relief in the medium term.

  7. Comparison of continuous interscalene block and subacromial infusion of local anesthetic for postoperative analgesia after open shoulder surgery.

    Science.gov (United States)

    Baskan, Semih; Cankaya, Deniz; Unal, Hidayet; Yoldas, Burak; Taspinar, Vildan; Deveci, Alper; Tabak, Yalcin; Baydar, Mustafa

    2017-01-01

    This study compared the efficacy of continuous interscalene block (CISB) and subacromial infusion of local anesthetic (CSIA) for postoperative analgesia after open shoulder surgery. This randomized, prospective, double-blinded, single-center study included 40 adult patients undergoing open shoulder surgery. All patients received a standardized general anesthetic. The patients were separated into group CISB and group CSIA. A loading dose of 40 mL 0.25% bupivacaine was administered and patient-controlled analgesia was applied by catheter with 0.1% bupivacaine 5 mL/h throughout 24 h basal infusion, 2 mL bolus dose, and 20 min knocked time in both groups postoperatively. Visual analog scale (VAS) scores, additional analgesia need, local anesthetic consumption, complications, and side effects were recorded during the first 24 h postoperatively. The range of motion (ROM) score was recorded preoperatively and in the first and third weeks postoperatively. A statistically significant difference was determined between the groups in respect of consumption of local anesthetic, VAS scores, additional analgesia consumption, complications, and side effects, with lower values recorded in the CISB group. There were no significant differences in ROM scoring in the preoperative and postoperative third week between the two groups but there were significant differences in ROM scoring in the postoperative first week, with higher ROM scoring values in the group CISB patients. The results of this study have shown that continuous interscalene infusion of bupivacaine is an effective and safe method of postoperative analgesia after open shoulder surgery.

  8. The influence of material hardness on liquid droplet impingement erosion

    International Nuclear Information System (INIS)

    Fujisawa, Nobuyuki; Yamagata, Takayuki; Takano, Shotaro; Saito, Kengo; Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio

    2015-01-01

    Highlights: • Liquid droplet impingement erosion is studied for various metal materials. • Average power dependency on droplet velocity is found as 7. • Power dependency on Vickers hardness is found as −4.5. • An empirical formula is constructed for erosion rates of metal materials. • Predicted erosion rate is well correlated with experiment within a factor of 1.5. - Abstract: This paper describes the experimental study on the liquid droplet impingement erosion of metal materials to understand the influence of material hardness on the erosion rate. The experiment is carried out using a water spray jet apparatus with a condition of relatively thin liquid film thickness. The metal materials tested are pure aluminum, aluminum alloy, brass, mild steel, carbon steel and stainless steel. The liquid droplets considered are 30 ± 5 μm in volume average diameter of water, which is the same order of droplet diameter in the actual pipeline in nuclear/fossil power plants. In order to understand the influence of material hardness on the liquid droplet impingement erosion, the scanning electron microscope (SEM) observation on the eroded surface and the measurement of erosion rate are carried out in the terminal stage of erosion. The experimental results indicate that the erosion rates are expressed by the droplet velocity, volume flux, Vickers hardness and the liquid film thickness, which are fundamentals of the liquid droplet impingement erosion. The empirical formula shows that the power index for droplet velocity dependency is found to be 7 with a scattering from 5 to 9 depending on the materials, while the power index for Vickers hardness dependency is found as −4.5

  9. Reliability, Readability and Quality of Online Information about Femoracetabular Impingement

    Directory of Open Access Journals (Sweden)

    Fatih Küçükdurmaz

    2015-07-01

    Conclusion: According to our results, the websites intended to attract patients searching for information regarding femoroacetabular impingement are providing a highly accessible, readable information source, but do not appear to apply a comparable amount of rigor to scientific literature or healthcare practitioner websites in regard to matters such as citing sources for information, supplying methodology and including a publication date. This indicates that while these resources are easily accessed by patients, there is potential for them to be a source of misinformation.

  10. Annular Impinging Jet Controlled by Radial Synthetic Jets

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Tesař, Václav; Broučková, Zuzana; Peszyński, K.

    2014-01-01

    Roč. 35, 16-17 (2014), s. 1450-1461 ISSN 0145-7632 R&D Projects: GA ČR GA14-08888S; GA AV ČR(CZ) IAA200760801 Institutional support: RVO:61388998 Keywords : impinging jet * hybrid synthetic jet * flow control Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 0.814, year: 2014 http://dx.doi.org/10.1080/01457632.2014.889467

  11. Radiographic Evidence of Femoroacetabular Impingement in Athletes With Athletic Pubalgia

    OpenAIRE

    Economopoulos, Kostas J.; Milewski, Matthew D.; Hanks, John B.; Hart, Joseph M.; Diduch, David R.

    2014-01-01

    Background: Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. Hypothesis: We hypothesized that patients with athletic pubalgia would have a high prevale...

  12. Excitational metamorphosis of surface flowfield under an impinging annular jet

    Czech Academy of Sciences Publication Activity Database

    Tesař, Václav; Trávníček, Zdeněk

    2008-01-01

    Roč. 144, č. 2 (2008), s. 312-316 ISSN 1385-8947 R&D Projects: GA ČR GA101/07/1499; GA AV ČR IAA200760705 Institutional research plan: CEZ:AV0Z20760514 Keywords : jets * impinging jets * flow topology * annular jets * stagnation points Subject RIV: BK - Fluid Dynamics Impact factor: 2.813, year: 2008 http://www.sciencedirect.com/

  13. The influence of material hardness on liquid droplet impingement erosion

    Energy Technology Data Exchange (ETDEWEB)

    Fujisawa, Nobuyuki, E-mail: fujisawa@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Yamagata, Takayuki, E-mail: yamagata@eng.niigata-u.ac.jp [Visualization Research Center, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Takano, Shotaro; Saito, Kengo [Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-Nocho, Nishi-ku, Niigata 950-2181 (Japan); Morita, Ryo; Fujiwara, Kazutoshi; Inada, Fumio [Central Research Institute of Electric Power Industry, 2-11-1, Iwatokita, Komae, Tokyo 201-8511 (Japan)

    2015-07-15

    Highlights: • Liquid droplet impingement erosion is studied for various metal materials. • Average power dependency on droplet velocity is found as 7. • Power dependency on Vickers hardness is found as −4.5. • An empirical formula is constructed for erosion rates of metal materials. • Predicted erosion rate is well correlated with experiment within a factor of 1.5. - Abstract: This paper describes the experimental study on the liquid droplet impingement erosion of metal materials to understand the influence of material hardness on the erosion rate. The experiment is carried out using a water spray jet apparatus with a condition of relatively thin liquid film thickness. The metal materials tested are pure aluminum, aluminum alloy, brass, mild steel, carbon steel and stainless steel. The liquid droplets considered are 30 ± 5 μm in volume average diameter of water, which is the same order of droplet diameter in the actual pipeline in nuclear/fossil power plants. In order to understand the influence of material hardness on the liquid droplet impingement erosion, the scanning electron microscope (SEM) observation on the eroded surface and the measurement of erosion rate are carried out in the terminal stage of erosion. The experimental results indicate that the erosion rates are expressed by the droplet velocity, volume flux, Vickers hardness and the liquid film thickness, which are fundamentals of the liquid droplet impingement erosion. The empirical formula shows that the power index for droplet velocity dependency is found to be 7 with a scattering from 5 to 9 depending on the materials, while the power index for Vickers hardness dependency is found as −4.5.

  14. Numerical study of the spray impingement onto a solid wall

    OpenAIRE

    Rodrigues, Christian Michel Gomes

    2011-01-01

    The modelling of turbulent multiphase flows has been gathering high interest in the last decades in the scientific community due to its relevance in several applications, such as in industrial and environmental processes or for chemical and biomedical purposes. In fact, regarding the industrial applications, the impingement of liquid fuel sprays onto engine surfaces has become a subject of interest due to its influence on the mixture preparation prior to combustion and, consequently, engine p...

  15. CFD analysis of the impingement cooling effect of the coolant jet caused by the T56 1st stage disc metering hole

    CSIR Research Space (South Africa)

    Snedden, Glen C

    2003-09-01

    Full Text Available conditions applied is given in Figure 2. Figures 3 to 7 give an overview of the final mesh and some idea of the block structured approach and refinement in the main area of interest, that is, the impingement zone and metering holes at the lower part... OF THE IMPINGEMENT COOLING EFFECT OF THE COOLANT JET CAUSED BY THE T56 1ST STAGE DISC METERING HOLE ISABE-2003-1065 Glen C. Snedden CSIR, Defencetek, P O Box 395 Pretoria, 0001, South Africa Tony Lambert Rolls-Royce Indianapolis, Indiana, USA Abstract...

  16. Methods on simple radiogaphy of impingement syndrome in shoulder joint

    International Nuclear Information System (INIS)

    Kweon, Dae Cheol; Kim, Moon Sun; Kim, Yong Seob; Chung, Kyung Mo

    2000-01-01

    To evaluation of patients who have shoulder impingement syndrome is by diagnostic radiography. Shoulder impingement is a problem which occurs in young, active individuals as well as older individuals. In fact, the pain is probably caused by repetitive stress placed on the shoulder joint either through recreational activities of your occupation. Impingement series approach to radiographic examination of the shoulder is take five projections. First anteroposterior oblique projection. Second standard anteroposterior projection. Third superoinferior axial projection. Fourth supraspinatus outlet projection offers a view of the outlet of the supraspinatus tendon unit as it passes under the coraacromial arch. Fifth anteroposterior 30 deg caudal projection will adequately demonstrate the anterior acromial spur or ossification in the coraacromial ligament and more reliable to demonstrate spurring of the anterior acromion than supraspinatus outlet projection. This decreased the need for additional radiographic veiws, reduces the patient's exposure to x-ray radiation and decreases use of film. This can lower the cost of the evaluation and improve patient satisfaction.=20

  17. Methods on simple radiogaphy of impingement syndrome in shoulder joint

    Energy Technology Data Exchange (ETDEWEB)

    Kweon, Dae Cheol; Kim, Moon Sun; Kim, Yong Seob; Chung, Kyung Mo [Seoul National Univ. College of Medicine, Seoul (Korea, Republic of)

    2000-06-01

    To evaluation of patients who have shoulder impingement syndrome is by diagnostic radiography. Shoulder impingement is a problem which occurs in young, active individuals as well as older individuals. In fact, the pain is probably caused by repetitive stress placed on the shoulder joint either through recreational activities of your occupation. Impingement series approach to radiographic examination of the shoulder is take five projections. First anteroposterior oblique projection. Second standard anteroposterior projection. Third superoinferior axial projection. Fourth supraspinatus outlet projection offers a view of the outlet of the supraspinatus tendon unit as it passes under the coraacromial arch. Fifth anteroposterior 30 deg caudal projection will adequately demonstrate the anterior acromial spur or ossification in the coraacromial ligament and more reliable to demonstrate spurring of the anterior acromion than supraspinatus outlet projection. This decreased the need for additional radiographic veiws, reduces the patient's exposure to x-ray radiation and decreases use of film. This can lower the cost of the evaluation and improve patient satisfaction.=20.

  18. Apollo Video Photogrammetry Estimation Of Plume Impingement Effects

    Science.gov (United States)

    Immer, Christopher; Lane, John; Metzger, Philip T.; Clements, Sandra

    2008-01-01

    The Constellation Project's planned return to the moon requires numerous landings at the same site. Since the top few centimeters are loosely packed regolith, plume impingement from the Lander ejects the granular material at high velocities. Much work is needed to understand the physics of plume impingement during landing in order to protect hardware surrounding the landing sites. While mostly qualitative in nature, the Apollo Lunar Module landing videos can provide a wealth of quantitative information using modem photogrammetry techniques. The authors have used the digitized videos to quantify plume impingement effects of the landing exhaust on the lunar surface. The dust ejection angle from the plume is estimated at 1-3 degrees. The lofted particle density is estimated at 10(exp 8)- 10(exp 13) particles per cubic meter. Additionally, evidence for ejection of large 10-15 cm sized objects and a dependence of ejection angle on thrust are presented. Further work is ongoing to continue quantitative analysis of the landing videos.

  19. Study on pipe wastage mechanism by liquid droplet impingement erosion

    International Nuclear Information System (INIS)

    Higashi, Yuma; Narabayashi, Tadashi; Shimazu, Yoichiro; Tsuji, Masashi; Ohmori, Shuichi; Mori, Michitsugu; Tezuka, Kenichi

    2009-01-01

    Evaluation of wastage speed for nuclear power plant maintains plant reliability and power up rating is important. There are two main cause of wastage flow accelerated corrosion (FAC) and mechanical erosion. This study is to develop evaluating the wastage speed by liquid droplet impingement erosion (LDIE). LDIE often occurs at downstream of corner of pipe or orifice. In this study, the liquid drop impinging tests were conducted with the test pieces mounted on a high speed rotating disk that cross thin water down jet and produced LDIE phenomena. The amount of the wastage by LDIE was evaluated by changing the rotational speed, the impingement frequency, and test piece materials. In addition, the generation mechanism of erosion was investigated by observing the surface of the test piece with a microscope. There is a method of evaluating by the mass difference before and after experiments. But this method is not correct because error becomes larger for mass measurement in the experiment, for the lost mass by LDIE is very little amount. Therefore, the method was developed to measure the volume in the erosion part. In this method, depth of LDIE was measured by the accuracy of ±0.01μm; therefore accurate measurement of the wastage can be improved. (author)

  20. Spray Formation of Herschel-Bulkley Fluids using Impinging Jets

    Science.gov (United States)

    Rodrigues, Neil; Gao, Jian; Chen, Jun; Sojka, Paul E.

    2015-11-01

    The impinging jet spray formation of two non-Newtonian, shear-thinning, Herschel-Bulkley fluids was investigated in this work. The water-based gelled solutions used were 1.0 wt.-% agar and 1.0 wt.-% kappa carrageenan. A rotational rheometer and a capillary viscometer were used to measure the strain-rate dependency of viscosity and the Herschel-Bulkley Extended (HBE) rheological model was used to characterize the shear-thinning behavior. A generalized HBE jet Reynolds number Rej , gen - HBE was used as the primary parameter to characterize the spray formation. A like-on-like impinging jet doublet was used to produce atomization. Shadowgraphs were captured in the plane of the sheet formed by the two jets using a CCD camera with an Nd:YAG laser beam providing the back-illumination. Typical behavior for impinging jet atomization using Newtonian liquids was not generally observed due to the non-Newtonian, viscous properties of the agar and kappa carrageenan gels. Instead various spray patterns were observed depending on Rej , gen - HBE. Spray characteristics of maximum instability wavelength and sheet breakup length were extracted from the shadowgraphs. Multi-University Research Initiative Grant Number W911NF-08-1-0171.

  1. Impingement wastage experiments with 9Cr 1Mo steel

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, S., E-mail: skishore@igcar.gov.in [IGCAR (India); Beauchamp, François; Allou, Alexandre [CEA (France); Kumar, A. Ashok; Chandramouli, S.; Rajan, K.K. [IGCAR (India)

    2016-02-15

    Highlights: • Sodium heated steam generators are crucial components of fast breeder reactors. • A leak in steam generator tube will cause sodium water reaction that damages the tubes. • A collaborative study by CEA and IGCAR was conducted to quantify the extent of damage on 9Cr 1Mo tube due to a steam/water leak. • It was compared against the predictions of PROPANA code. - Abstract: Steam Generator (SG) is one of the vital components of sodium cooled fast reactor (SFR). The main safety concern with SG is a probable sodium–water reaction. In case, one of its water/steam carrying tubes leaks, water/steam gets into contact with sodium causing sodium-water reaction, which is highly exothermic and producing corrosive NaOH and hydrogen. The ejecting reaction products at high temperature, impinges upon adjacent tubes by a process called impingement wastage. It could damage one of the neighboring tubes in a short time, if the detection and protection systems are failing. IGCAR and CEA carried out a collaborative study on impingement wastage of 9Cr 1Mo steel, which is one of the candidate materials for SFR SG tubes. The studies comprise of experimental works at IGCAR and simulation works with PROPANA code at CEA. This paper brings out the data and experience gained through this cooperative work.

  2. Ultrasound-guided subacromial injections of sodium hyaluronate for the management of rotator cuff tendinopathy: a prospective comparative study with rehabilitation therapy.

    Science.gov (United States)

    Merolla, G; Bianchi, P; Porcellini, G

    2013-06-01

    Rotator cuff (RC) tendinopathy is a common cause of pain and shoulder dysfunction. The literature evidence suggests that a combination of overuse and extrinsic compression may induce chronic RC tendinopathy. Aim of the current study was to compare the results of subacromial sodium hyaluronate injections with rehabilitation therapy. We enrolled 48 patients (M/F: 26/22; mean age: 50 years; shoulder right/left: 29/19) with persistent shoulder pain for at least 4 months. Exclusion criteria were as follows: RC tear, calcifying tendinitis, glenohumeral instability, osteoarthritis, rheumatic diseases, physical therapy and/or injection in the previous 4 months, shoulder surgery, anesthetic nerve block, trauma, and severe medical diseases. The included subjects received either two ultrasound-guided subacromial hyaluronic acid (HA) injections (25 patients, HA group) at baseline and 14 days, or underwent rehabilitation therapy (23 patients, Physio group) including active shoulder mobilization, soft tissue stretching and humeral head positioner and propeller muscles strengthening for 30 days (3 sessions every week). Clinical assessment of shoulder function was performed with visual analog scale score for pain (0-100), Oxford Shoulder Score (OSS), and Constant-Murley Score (CS). Overall, patients were examined at baseline, week 2, week 4, week 12, and week 24. Statistical significance was set at 5 % (p  0.05), week 12 (p > 0.05), and week 24 (p > 0.05). CS and OSS in the HA group increased significantly at week 2 (p  0.05). A significant improvement of CS and OSS we found in the Physio group at week 2 (p  0.05). Subacromial HA injections could be an effective and safe alternative treatment for patients suffering from RC tendinopathy. We believe that the results of this study are encouraging but not lasting and we might suppose that a series of three to four subacromial sodium hyaluronate injections could provide good mid- and long-term clinical benefits.

  3. Lipoma arborescens: rare case of rotator cuff tear associated with the presence of lipoma arborescens in the subacromial-subdeltoid and glenohumeral bursa

    OpenAIRE

    Benegas, Eduardo; Ferreiro Neto, Arnaldo Amado; Teodoro, Daniel Sabatini; Silva, Marcos Vinícius Muriano da; Oliveira, Augusto Medaglia de; Filippi, Renée Zon; Prada, Flávia de Santis

    2012-01-01

    Lipoma arborescens é uma condição rara de moléstia intra-articular, usualmente monoarticular, caracterizada por extensa proliferação dos vilos sinoviais e hiperplasia da gordura subsinovial. O tecido sinovial é progressivamente substituído por células maduras de gordura na membrana sinovial. O presente trabalho é o relato de caso de uma condição rara de lipoma arborescens tanto intra-articular (glenoumeral) como da bursa subacromial-subdeltoide além de ruptura do tendão do supraespinhoso. As ...

  4. Numerical modeling and validation of helium jet impingement cooling of high heat flux divertor components

    International Nuclear Information System (INIS)

    Koncar, Bostjan; Simonovski, Igor; Norajitra, Prachai

    2009-01-01

    Numerical analyses of jet impingement cooling presented in this paper were performed as a part of helium-cooled divertor studies for post-ITER generation of fusion reactors. The cooling ability of divertor cooled by multiple helium jets was analysed. Thermal-hydraulic characteristics and temperature distributions in the solid structures were predicted for the reference geometry of one cooling finger. To assess numerical errors, different meshes (hexagonal, tetra, tetra-prism) and discretisation schemes were used. The temperatures in the solid structures decrease with finer mesh and higher order discretisation and converge towards finite values. Numerical simulations were validated against high heat flux experiments, performed at Efremov Institute, St. Petersburg. The predicted design parameters show reasonable agreement with measured data. The calculated maximum thimble temperature was below the tile-thimble brazing temperature, indicating good heat removal capability of reference divertor design. (author)

  5. A study on the velocity characteristics of the spray formed by two impinging jets

    International Nuclear Information System (INIS)

    Choo, Yeon Jun; Seo, Kwi Hyun; Kang, Bo Seon

    2001-01-01

    In this study, the velocity characteristics of liquid elements formed by two impinging jets is analysed using double pulse image capturing technique. For the droplets formed by low speed impinging jets, the droplet velocities are higher with smaller azimuthal and impingement angle. The maximum droplet velocities are about 25% lower than jet velocity. With an increase of azimuthal angle, the shedding angles increases but remains lower than azimuthal angle. The velocities of ligaments formed by high speed impinging jets gradually decreases with an increase of azimuthal angle. The maximum ligament velocities are about 40% lower than jet velocity. Higher impingement angles produce lower ligament velocities. The shedding angles of ligament almost increases with the same value of azimuthal angle, which implies that the moving direction of ligaments is radial from the origin as the impingement point

  6. Experimental study on boiling heat transfer to an impinging jet on a hot block

    International Nuclear Information System (INIS)

    Kamata, Choko

    1997-01-01

    Previous studies on boiling heat transfer by impinging jets are mainly concerned with the impinging point by using small heat transfer surfaces of about 20 mm. An experimental study of the boiling heat transfer to an impinging water jet on a massive hot block is made. The upward heating surface is made of copper. Its diameter and nozzle diameter are 80 mm and 2.2 mm, respectively. The velocity of the impinging jet was varied from 0.6 to 2.1 m/s. Saturated water normally impinged on the heating surface, flowed radially, and subsequently dispersed into the atmosphere. The present study clarifies that heat transfer characteristics vary with the temperature of heat transfer surface, and also with the distance from the impinging point. (author)

  7. Comparison of Endotoxin Exposure Assessment by Bioaerosol Impinger and Filter-Sampling Methods

    OpenAIRE

    Duchaine, Caroline; Thorne, Peter S.; Mériaux, Anne; Grimard, Yan; Whitten, Paul; Cormier, Yvon

    2001-01-01

    Environmental assessment data collected in two prior occupational hygiene studies of swine barns and sawmills allowed the comparison of concurrent, triplicate, side-by-side endotoxin measurements using air sampling filters and bioaerosol impingers. Endotoxin concentrations in impinger solutions and filter eluates were assayed using the Limulus amebocyte lysate assay. In sawmills, impinger sampling yielded significantly higher endotoxin concentration measurements and lower variances than filte...

  8. Rilonacept in the treatment of subacromial bursitis: A randomized, non-inferiority, unblinded study versus triamcinolone acetonide.

    Science.gov (United States)

    Carroll, Matthew B; Motley, Spencer A; Wohlford, Susanna; Ramsey, Bryan C

    2015-12-01

    Subacromial bursitis is caused by inflammation of the bursa that separates the superior surface of the supraspinatus tendon from the overlying coraco-acromial ligament and acromion. While multiple cytokines are implicated, interleukin-1 beta appears to play a prominent role. Rilonacept, an interleukin-1 trap, may be an alternative to corticosteroid injection for the management of this condition. This single center, randomized, non-inferiority, unblinded study recruited 33 subjects over 9 months. Twenty subjects received 160mg intrabursal injection of rilonacept and 13 received a 6mL mixture of lidocaine, bupivacaine, and 80mg triamcinolone acetonide. QuickDASH, subject reported pain, and adverse events were recorded at time of injection, 2 days later, 2 weeks later, and 4 weeks later. Primary outcome was improvement in QuickDASH 4 weeks post-injection. Secondary outcomes were improvement in subject reported pain and occurrence of adverse events at 4 weeks. Both study groups were equally matched for age, gender, ethnicity, and site of bursa injection. Both medications demonstrated a statistically significant improvement in QuickDASH 4 weeks post-injection, but triamcinolone acetonide injection offered greater improvement (P=0.004). Both medications demonstrated improvement in subject reported pain but between group comparison at 4 weeks showed that triamcinolone was superior (P=0.044). No statistically significant differences in adverse events were noted between groups, but subjects who received rilonacept experienced more episodes of diarrhea and headache. While improvement in QuickDASH and pain was noted with a single intrabursal injection of rilonacept at 4 weeks, injection with triamcinolone acetonide was more efficacious. This trial was registered with www.clinicaltrials.gov (NCT01830699). Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  9. Development of Augmented Spark Impinging Igniter System for Methane Engines

    Science.gov (United States)

    Marshall, William M.; Osborne, Robin J.; Greene, Sandra E.

    2017-01-01

    The Lunar Cargo Transportation and Landing by Soft Touchdown (Lunar CATALYST) program is establishing multiple no-funds-exchanged Space Act Agreement (SAA) partnerships with U.S. private sector entities. The purpose of this program is to encourage the development of robotic lunar landers that can be integrated with U.S. commercial launch capabilities to deliver payloads to the lunar surface. NASA can share technology and expertise under the SAA for the benefit of the CATALYST partners. MSFC seeking to vacuum test Augmented Spark Impinging (ASI) igniter with methane and new exciter units to support CATALYST partners and NASA programs. ASI has previously been used/tested successfully at sea-level, with both O2/CH4 and O2/H2 propellants. Conventional ignition exciter systems historically experienced corona discharge issues in vacuum. Often utilized purging or atmospheric sealing on high voltage lead to remedy. Compact systems developed since PCAD could eliminate the high-voltage lead and directly couple the exciter to the spark igniter. MSFC developed Augmented Spark Impinging (ASI) igniter. Successfully used in several sea-level test programs. Plasma-assisted design. Portion of ox flow is used to generate hot plasma. Impinging flows downstream of plasma. Additional fuel flow down torch tube sleeve for cooling near stoichiometric torch flame. Testing done at NASA GRC Altitude Combustion Stand (ACS) facility 2000-lbf class facility with altitude simulation up to around 100,000 ft. (0.2 psia [10 Torr]) via nitrogen driven ejectors. Propellant conditioning systems can provide temperature control of LOX/CH4 up to test article.

  10. Study of Plume Impingement Effects in the Lunar Lander Environment

    Science.gov (United States)

    Marichalar, Jeremiah; Prisbell, A.; Lumpkin, F.; LeBeau, G.

    2010-01-01

    Plume impingement effects from the descent and ascent engine firings of the Lunar Lander were analyzed in support of the Lunar Architecture Team under the Constellation Program. The descent stage analysis was performed to obtain shear and pressure forces on the lunar surface as well as velocity and density profiles in the flow field in an effort to understand lunar soil erosion and ejected soil impact damage which was analyzed as part of a separate study. A CFD/DSMC decoupled methodology was used with the Bird continuum breakdown parameter to distinguish the continuum flow from the rarefied flow. The ascent stage analysis was performed to ascertain the forces and moments acting on the Lunar Lander Ascent Module due to the firing of the main engine on take-off. The Reacting and Multiphase Program (RAMP) method of characteristics (MOC) code was used to model the continuum region of the nozzle plume, and the Direct Simulation Monte Carlo (DSMC) Analysis Code (DAC) was used to model the impingement results in the rarefied region. The ascent module (AM) was analyzed for various pitch and yaw rotations and for various heights in relation to the descent module (DM). For the ascent stage analysis, the plume inflow boundary was located near the nozzle exit plane in a region where the flow number density was large enough to make the DSMC solution computationally expensive. Therefore, a scaling coefficient was used to make the DSMC solution more computationally manageable. An analysis of the effectiveness of this scaling technique was performed by investigating various scaling parameters for a single height and rotation of the AM. Because the inflow boundary was near the nozzle exit plane, another analysis was performed investigating three different inflow contours to determine the effects of the flow expansion around the nozzle lip on the final plume impingement results.

  11. Experimental investigation of submerged single jet impingement using Cu–water nanofluid

    International Nuclear Information System (INIS)

    Li Qiang; Xuan Yimin; Yu Feng

    2012-01-01

    Jet impingement cooling is a vital technique for thermal management of electronic devices of high-heat-flux by impinging fluid on a heater surface due to its high local heat transfer rates. In this paper, two types of Cu–water nanofluids (Cu particles with 25 nm diameter or 100 nm) are introduced into submerged single jet impingement cooling system as the working fluid. The heat transfer features of the nanofluids were experimentally investigated. The effects of the nanoparticle concentration, Reynolds number, nozzle-to-plate distance, fluid temperature, and nanoparticle diameter on the heat transfer performances of the jet impingement of nanofluids are discussed. The experimental results show that the suspended nanoparticles remarkably increase the convective heat transfer coefficient of the base fluid. The convective heat transfer coefficient of Cu–water nanofluid with the volume fraction of 3.0% has 52% higher than the pure water. The experiments also revealed that the suspended nanoparticles brought almost no extra addition of pressure drop in both submerged single jet impingement. In addition, by considering the effects of the suspended nanoparticles as well as the condition of impinging jet, a new heat transfer correlation of nanofluids for the submerged single jet impingement has been proposed. - Highlights: ► Cu–water nanofluids are introduced into submerged single jet impingement. ► The affecting parameters on the heat transfer performances of nanofluids are discussed. ► New heat transfer correlation of nanofluid for single jet impingement is proposed.

  12. Multiple flow patterns and heat transfer in confined jet impingement

    International Nuclear Information System (INIS)

    Li Xianchang; Gaddis, J. Leo; Wang Ting

    2005-01-01

    The flow field of a 2-D laminar confined impinging slot jet is investigated. Numerical results indicate that there exist two different solutions in some range of geometric and flow parameters. The two steady flow patterns are obtained under identical boundary conditions but only with different initial flow fields. Two different exit boundary conditions are investigated with two commercial software packages to eliminate artificial or computational effects. The different flow patterns are observed to significantly affect the heat transfer. A flow visualization experiment is carried out to verify the computational results and both flow patterns are observed. The bifurcation mechanism is interpreted and discussed

  13. MAGNETIC RESONANCE IMAGING EVALUATION OF ROTATOR CUFF IMPINGEMENT

    Directory of Open Access Journals (Sweden)

    Chandrakanth K. S

    2017-06-01

    Full Text Available BACKGROUND Shoulder pain is a common clinical problem. Impingement syndrome of the shoulder is believed to be the most common cause of shoulder pain. The term ‘impingement syndrome’ was first used by Neer to describe a condition of shoulder pain associated with chronic bursitis and partial thickness tear of Rotator Cuff (RC. The incidence of Rotator Cuff (RC tear is estimated to be about 20.7% in the general population. This study is intended to analyse various extrinsic and intrinsic causes of shoulder impingement. MATERIALS AND METHODS 110 consecutive patients referred for MRI with clinical suspicion of shoulder impingement were prospectively studied. All the patients were evaluated for Rotator Cuff (RC degeneration and various extrinsic factors that lead to degeneration like acromial shape, down-sloping acromion, Acromioclavicular (AC joint degeneration and acromial enthesophyte. Intrinsic factors like degeneration and its correlation with age of the patients were evaluated. RESULTS Of the total 110 patients, 19 (17.3% patients had FT RC tear and 31 (28.2% had PT (both bursal and articular surface tears. There was no statistically significant correlation (p=0.76 between acromion types and RC tear. Down-sloping acromion and enthesophytes had statistically significant association with RC tear (p=0.008 and 0.008, respectively. Statistically significant (0.008 correlation between the severity of AC joint degeneration and RC tears was noted. AC joint degeneration and RC pathologies also showed a correlation with the age of the patients with p values of <0.001 and 0.001, respectively. CONCLUSION No statistically significant correlation between RC pathologies with hooked acromion was found, that makes the role played by hooked acromion in FT RC tear questionable. AC joint degeneration association with RC tear is due to the association of both RC tear and AC joint degeneration with age of the patient. Down-sloping acromion, AC joint degeneration

  14. Numerical simulation of a low-swirl impinging jet with a rotating convergent nozzle

    Science.gov (United States)

    Borynyak, K.; Hrebtov, M.; Bobrov, M.; Kozyulin, N.

    2018-03-01

    The paper presents the results of Large Eddy Simulation of a swirling impinging jet with moderate Reynolds number (104), where the swirl is organized via the rotation of a convergent nozzle. The results show that the effect of the swirl in this configuration leads to an increase of axial velocity, compared to the non-swirling case. It is shown that turbulent stress plays an important role in this effect. The vortex structure of the jet consists of multiple pairs of nearly parallel helical vortices with opposite signs of rotation. The interaction of vortices in the near region of the jet leads to radial contraction of the jet’s core which in turn, causes an the increase in the axial velocity.

  15. Single-phase liquid jet impingement heat transfer

    International Nuclear Information System (INIS)

    Webb, B.W.; Ma, C.F.

    1995-01-01

    Impinging liquid jets have been demonstrated to be an effective means of providing high heat/mass transfer rates in industrial transport processes. When a liquid jet strikes a surface, thin hydrodynamic and thermal boundary layers from in the region directly beneath due to the jet deceleration and the resulting increase in pressure. The flow is then forced to accelerate in a direction parallel to the target surface in what is termed the wall jet or parallel flow zone. The thickness of the hydrodynamic and thermal boundary layers in the stagnation region may be of the order of tens of micrometers. Consequently, very high heat/mass transfer coefficients exist in the stagnation zone directly under the jet. Transport coefficients characteristic of parallel flow prevail in the wall jet region. The high heat transfer coefficients make liquid jet impingement an attractive cooling option where high heat fluxes are the norm. Some industrial applications include the thermal treatment of metals, cooling of internal combustion engines, and more recently, thermal control of high-heat-dissipation electronic devices. Both circular and planar liquid jets have attracted research attention. 180 refs., 35 figs., 11 tabs

  16. Experimentally induced cam impingement in the sheep hip.

    Science.gov (United States)

    Siebenrock, Klaus A; Fiechter, Ruth; Tannast, Moritz; Mamisch, Tallal C; von Rechenberg, Brigitte

    2013-04-01

    Sheep hips have a natural non-spherical femoral head similar to a cam-type deformity in human beings. By performing an intertrochanteric varus osteotomy, cam-type femoro-acetabular impingement (FAI) during flexion can be created. We tested the hypotheses that macroscopic lesions of the articular cartilage and an increased Mankin score (MS) can be reproduced by an experimentally induced cam-type FAI in this ovine in vivo model. Furthermore, we hypothesized that the MS increases with longer ambulatory periods. Sixteen sheep underwent unilateral intertrochanteric varus osteotomy of the hip with the non-operated hip as a control. Four sheep were sacrificed after 14, 22, 30, and 38-weeks postoperatively. We evaluated macroscopic chondrolabral alterations, and recorded the MS, based on histochemical staining, for each ambulatory period. A significantly higher prevalence of macroscopic chondrolabral lesions was found in the impingement zone of the operated hips. The MS was significantly higher in the acetabular/femoral cartilage of the operated hips. Furthermore, these scores increased as the length of the ambulatory period increased. Cam-type FAI can be induced in an ovine in vivo model. Localized chondrolabral degeneration of the hip, similar to that seen in humans (Tannast et al., Clin Orthop Relat Res 2008; 466: 273-280; Beck et al., J Bone Joint Surg Br 2005; 87: 1012-1018), can be reproduced. This experimental sheep model can be used to study cam-type FAI. Copyright © 2012 Orthopaedic Research Society.

  17. Preliminary study of image findings of femoroacetabular impingement

    International Nuclear Information System (INIS)

    Guo Zhe; Zhang Jing; Hong Nan; Cheng Xiaoguang

    2010-01-01

    Objective: To assess the image findings of femoroacetabular impingement (FAI). Methods: Image findings of 9 patients with surgically proved femoroacetabular impingement were retrospectively reviewed for characteristic image findings of FAI. All 9 patients underwent X-ray examinations and MRI of affected hip, and 1 patient underwent MR arthrography (MRA) additionally. Results: X-ray examinations of all 9 patients showed bump at femoral head-neck junction or overcoverage of the acetabular. MRI showed various degrees of injury of anterosuperior labrum in all 9 patients. The injuries were stage Ⅰ A in 2 cases, stage Ⅰ B in 3, stage Ⅱ A in 2, and stage Ⅱ B in 2. MRA of the case showed tears of anterosuperior labrum, with contrast media entering into the teared labrum. There were sclerosis and cystic degeneration of subchondral bone of femoral head in 2 cases, and these findings were confirmed as cartilage delamination by surgery. Conclusions: MRI can display the injures of labrum and articular cartilage, which is helpful to the early diagnosis of' FAI. (authors)

  18. Global mode decomposition of supersonic impinging jet noise

    Science.gov (United States)

    Hildebrand, Nathaniel; Nichols, Joseph W.

    2015-11-01

    We apply global stability analysis to an ideally expanded, Mach 1.5, turbulent jet that impinges on a flat surface. The analysis extracts axisymmetric and helical instability modes, involving coherent vortices, shocks, and acoustic feedback, which we use to help explain and predict the effectiveness of microjet control. High-fidelity large eddy simulations (LES) were performed at nozzle-to-wall distances of 4 and 4.5 throat diameters with and without sixteen microjets positioned uniformly around the nozzle lip. These flow configurations conform exactly to experiments performed at Florida State University. Stability analysis about LES mean fields predicted the least stable global mode with a frequency that matched the impingement tone observed in experiments at a nozzle-to-wall distance of 4 throat diameters. The Reynolds-averaged Navier-Stokes (RANS) equations were solved at five nozzle-to-wall distances to create base flows that were used to investigate the influence of this parameter. A comparison of the eigenvalue spectra computed from the stability analysis about LES and RANS base flows resulted in good agreement. We also investigate the effect of the boundary layer state as it emerges from the nozzle using a multi-block global mode solver. Computational resources were provided by the Argonne Leadership Computing Facility.

  19. Visualization and modeling of the hydrodynamics of an impinging microjet.

    Science.gov (United States)

    Bitziou, Eleni; Rudd, Nicola C; Edwards, Martin A; Unwin, Patrick R

    2006-03-01

    The use of fluorescence confocal laser scanning microscopy (CLSM) for flow visualization is described, with a focus on elucidating the pattern of flow in the microjet electrode (MJE). The MJE employs a nozzle, formed from a fine glass capillary, with an inner diameter of approximately 100 microm, to direct solution at an electrode surface, using high velocity but at moderate volume flow rates. For CLSM visualization, the jetted solution contains a fluorescent probe, fluorescein at high pH, which flows into a solution buffered at low pH, where the fluorescence is extinguished, thereby highlighting the flow field of the impinging microjet. The morphology of the microjet and the hydrodynamic boundary layer are shown to be highly sensitive to the volume flow rate, with a collimated jet and thin boundary layer formed at the faster flow rates (approximately 1 cm(3) min(-1)). In contrast, at lower flow rates and for relatively large substrates, an unusual recirculation zone is observed experimentally for the first time. This effect can be eliminated by employing small substrates. The experimental observations have been quantified through numerical solution of the Navier-Stokes equations of continuity and momentum balance. The new insights provided by CLSM imaging demonstrate that flow in the MJE, and impinging jets in general, are more complex than predicted by classical models but are well-defined and quantifiable.

  20. Controlled antisolvent precipitation of spironolactone nanoparticles by impingement mixing.

    Science.gov (United States)

    Dong, Yuancai; Ng, Wai Kiong; Shen, Shoucang; Kim, Sanggu; Tan, Reginald B H

    2011-05-30

    Continuous antisolvent precipitation of spironolactone nanoparticles were performed by impingement mixing in this work. In the range of Reynolds numbers (Re) 2108-6325 for the antisolvent water stream and 1771-5313 for the solvent stream, i.e. acetonic drug solution, 302-360 nm drug nanoparticles were achieved. Increasing drug concentration from 25 to 50 and 100 mg/ml led to a significant size increase from 279.0±2.6 to 302.7±4.9 and 446.0±17.3 nm, respectively. "Two-step crystallization" was first observed for spironolactone in the water/acetone system: the drug was precipitated initially as spherical cluster, which rearranged into ordered cuboidal nanocrystals finally. The nanoformulation showed faster dissolution rate in comparison with the raw drug. By combining the impingement mixing and an on-line spray drying, a fully continuous process may be developed for mass-production of dried drug nanoparticles. Copyright © 2011 Elsevier B.V. All rights reserved.

  1. Empirical model of impingement impact. Environmental Sciences Division publication No. 1289

    International Nuclear Information System (INIS)

    Barnthouse, L.W.; DeAngelis, D.L.; Christensen, S.W.

    1979-01-01

    A simple model, derived from Ricker's (1975) theory of fisheries dynamics, that can be used to estimate the impact of impingement of juvenile fish by power plants on year-class abundance in vulnerable species is described. The only data required are estimates of the initial number of impingeable juveniles, the number impinged, and the rate of total mortality during the period of vulnerability. The impact of impingement is expressed in the model as the conditional mortality rate, rather than the more commonly used exploitation rate. The conditional mortality rate is superior as a measure of impact for two reasons: it accounts for the differential impact of impinging fish of different ages, and it is numerically equivalent to the fractional reduction in year-class abundance due to impingement. We present an application of the model using the 1974 year-class of the Hudson River striped bass population as an example. We then show how the model can be modified to account for seasonal fluctuations in the rate of impingement, discuss the effect of these fluctuations on the calculated impact, and discuss the influence on model output of errors in the measurement of abundance, impingement, and total mortality. It is evident from this analysis that estimates of impingement impact are as sensitive to errors in estimates of population size and mortality as to estimates of the number of fish impinged. Thus, it is not possible to reliably estimate the impact of impingement on a vulnerable fish species unless a substantial effort is devoted to population studies

  2. Physics of Particle Entrainment Under the Influence of an Impinging Jet

    Science.gov (United States)

    2008-12-01

    Approved for public release; distribution unlimited 1 PHYSICS OF PARTICLE ENTRAINMENT UNDER THE INFLUENCE OF AN IMPINGING JET Robert Haehnel...Ing. Wesen. Heft 361). Phares, D.J., Smedley , G.T. and Flagan, R.C. (2000) "The wall shear stress produced by the normal impingement of a jet on a

  3. Trailing edge cooling using angled impingement on surface enhanced with cast chevron arrangements

    Science.gov (United States)

    Lee, Ching-Pang; Heneveld, Benjamin E.; Brown, Glenn E.; Klinger, Jill

    2015-05-26

    A gas turbine engine component, including: a pressure side (12) having an interior surface (34); a suction side (14) having an interior surface (36); a trailing edge portion (30); and a plurality of suction side and pressure side impingement orifices (24) disposed in the trailing edge portion (30). Each suction side impingement orifice is configured to direct an impingement jet (48) at an acute angle (52) onto a target area (60) that encompasses a tip (140) of a chevron (122) within a chevron arrangement (120) formed in the suction side interior surface. Each pressure side impingement orifice is configured to direct an impingement jet at an acute angle onto an elongated target area that encompasses a tip of a chevron within a chevron arrangement formed in the pressure side interior surface.

  4. An experimental study of the supersonic, dual, coaxial jets impinging on an inclined flat plate

    International Nuclear Information System (INIS)

    Kim, Jung Bae; Lee, Jun Hee; Woo, Sun Hoon; Kim, Heuy Dong

    2002-01-01

    The impinging supersonic jets have been applied for rocket launching system, thrust control, gas turbine blade cooling, etc. Recently the supersonic, dual, coaxial jets are being extensively used in many diverse fields of industrial processes since they lead to more improved performance, compared with the conventional supersonic jets impinging on an object. In the present study, experimentation is carried out to investigate the supersonic, dual, coaxial jets impinging on an inclined flat plate. A convergent-divergent nozzle with a design Mach number of 2.0 and annular sonic nozzle are used to make the dual, coaxial jet flows. The angle of the impinging flat plate is varied from 30 .deg. to 60 .deg. and the distance between the dual coaxial nozzle and flat plate is also varied. Detailed pressures on the impinging plate are measured to analyze the flow fields, which are also visualized using Schlieren optical method

  5. Modular jet impingement assemblies with passive and active flow control for electronics cooling

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Feng; Dede, Ercan Mehmet; Joshi, Shailesh

    2016-09-13

    Power electronics modules having modular jet impingement assembly utilized to cool heat generating devices are disclosed. The modular jet impingement assemblies include a modular manifold having a distribution recess, one or more angled inlet connection tubes positioned at an inlet end of the modular manifold that fluidly couple the inlet tube to the distribution recess and one or more outlet connection tubes positioned at an outlet end of the modular manifold that fluidly coupling the outlet tube to the distribution recess. The modular jet impingement assemblies include a manifold insert removably positioned within the distribution recess and include one or more inlet branch channels each including an impinging slot and one or more outlet branch channels each including a collecting slot. Further a heat transfer plate coupled to the modular manifold, the heat transfer plate comprising an impingement surface including an array of fins that extend toward the manifold insert.

  6. Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

    Energy Technology Data Exchange (ETDEWEB)

    MacMahon, P.J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland)]. E-mail: petermacmahon@yahoo.com; Taylor, D.H. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Duke, D. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Brennan, D.D. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); O' Brien, J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland); Eustace, S.J. [Department of Radiology, Cappagh National Orthopaedic Hospital, Finglas, Dublin (Ireland)

    2007-06-15

    Aim: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. Materials and methods: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. Results: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p < 0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p < 0.05). There were no significant differences in coraco-humeral distances between the groups. Conclusion: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed.

  7. Contribution of full-thickness supraspinatus tendon tears to acquired subcoracoid impingement

    International Nuclear Information System (INIS)

    MacMahon, P.J.; Taylor, D.H.; Duke, D.; Brennan, D.D.; O'Brien, J.; Eustace, S.J.

    2007-01-01

    Aim: To assess the relationship between the severity of full-thickness supraspinatus tendon tears and the development of subcoracoid impingement. Materials and methods: Fifty-one magnetic resonance imaging (MRI) shoulder examination reports with full-thickness supraspinatus tears were retrospectively identified and reviewed by two dedicated musculoskeletal radiologists. The appearances of the rotator cuff muscles, biceps tendon and the lesser tubercle were recorded. The acromio-humeral distance and the axial coraco-humeral distance were measured. The data were recorded and analysed electronically. Results: The kappa values for inter-observer agreement were: 0.91 for acromio-humeral distance and 0.85 for coraco-humeral distance measurements. Twenty-six patients had significant retraction of the supraspinatus tendon, 85% (22 cases) of this group had imaging evidence of tear or tendonopathy of the subscapularis tendon. Twenty-five patients had no significant retraction of the supraspinatus, 56% (14 cases) of this group had imaging evidence of a subscapularis tear or tendonopathy. The acromio-humeral distance was significantly less in patients with supraspinatus tears and retraction (p < 0.05). The subscapularis tendon was significantly more likely to be abnormal if the supraspinatus was retracted than if no retraction was present (p < 0.05). There were no significant differences in coraco-humeral distances between the groups. Conclusion: Subscapularis tendon signal and structural changes are frequently associated with full-thickness supraspinatus tendon tears, particularly if the supraspinatus is significantly retracted. In this static MRI series, the data do not support the occurrence of classical subcoracoid impingement as an aetiology; however, they may support the possibility of a dynamic mechanism, to which future studies could be directed

  8. Development of a clinically relevant impingement test method for a mobile bearing lumbar total disc replacement.

    Science.gov (United States)

    Siskey, Ryan; Peck, Jonathan; Mehta, Hitesh; Kosydar, Allison; Kurtz, Steven; Hill, Genevieve

    2016-09-01

    Total disc arthroplasty is an alternative therapy to spinal fusion for the treatment of neck or low back pain and is hypothesized to reduce the risk of disease progression to the adjacent spinal levels. Radiographic and retrieval analyses of various total disc replacements (TDRs) have shown evidence of impingement damage. Impingement of TDRs can occur when the device reaches the limits of its functional range of motion, causing contact between peripheral regions of the device. Impingement can be associated with increased wear and mechanical damage; however, impingement conditions are not simulated in current standardized mechanical bench test methods. This study explored the test conditions necessary to apply clinically relevant impingement loading to a lumbar TDR in vitro. An experimental protocol was developed and evaluated using in vivo retrievals for qualitative and quantitative validation. Retrieval analysis was conducted on a set of 11 size 3 retrieved Charité devices using American Society for Testing and Materials F561 as a guide. The impingement range of motion was determined using a combination of modeling and experiments, and was used as an input in vitro testing. A 1-million cycle in vitro test was then conducted, and the in vitro samples were characterized using methods similar to the retreived devices. All in vitro tested samples exhibited impingement regions and damage patterns consistent with retrieved devices. Consistent with the retrievals, the impingement damage on the rim was a combination of abrasive wear and plastic deformation. Micro computed tomography (microCT) was used to quantitatively assess rim damage due to impingement. Rim penetration was statistically lower in the retrievals when compared with both in vitro groups. Rim elongation was comparable among all groups. The simulated-facet group had statistically greater angular rim deformations than the retrieval group and the no-facet group. Results demonstrate that clinically relevant

  9. Entrainment and impingement of aquatic fauna at cooling water system of Madras Atomic Power Station (MAPS)

    International Nuclear Information System (INIS)

    Barath Kumar, S.; Das, N.P.I.; Satpathy, K.K.

    2015-01-01

    Marine organisms get impinged to the intake screens of Madras Atomic Power Station (MAPS) due to the suction force of the cooling water system of the power plant. The present work has studied the loss of aquatic organism at MAPS due to impingement at cooling water screens. In total 67 species of marine faunas impinged on the water intake screens of MAPS during the study. The proportion of fish, shrimp, crab, jellyfish and others, with respect to the total biomass of impinged organisms are 1.59 % (33 species), 0.30% (9), 2.77 % (16), 95.10% (3) and 0.24% (4), respectively. Jellyfishes were observed to be the largest entrained group covering around 44.85% of individual and constituting almost 94.82 % of biomass recorded during the study period and sea nettle jelly (Chrysaora quinquecirrha) was impinged with highest frequency. The diel study shows higher impingement occurred during night time, on full moon day and at low tides in contrast to their counterparts. Fishes accounts for 14.84 % of individual count and mere 1.67 % of biomass. Totally 33 number of fish species were observed. The highest impinged species were pony fishes (Secutor ruconius, Secutor insidiator, Photopectoralis bindus, Alepes kleinii and Leiognathus equulus) (21% occurrence). These few entrained fishes are mostly very small in size and have less commercial value. The total loss of marine fauna by impingement during study period was estimated to be 4779 (or 463.46 kg). The present data when compared with the impingement data from other coastal power plants, shows that the impinged fish biomass at MAPS cooling water system is much less than the other temperate and tropical power plants. (author)

  10. Effect of coating material on heat transfer and skin friction due to impinging jet onto a laser producedhole

    Science.gov (United States)

    Shuja, S. Z.; Yilbas, B. S.

    2013-07-01

    Jet impingement onto a two-layer structured hole in relation to laser drilling is investigated. The hole consists of a coating layer and a base material. The variations in the Nusselt number and the skin friction are predicted for various coating materials. The Reynolds stress turbulent model is incorporated to account for the turbulence effect of the jet flow and nitrogen is used as the working fluid. The study is extended to include two jet velocities emanating from the conical nozzle. It is found that coating material has significant effect on the Nusselt number variation along the hole wall. In addition, the skin friction varies considerably along the coating thickness in thehole.

  11. Experimental studies on transient water-steam impinging jet

    International Nuclear Information System (INIS)

    Kitade, Kozo; Nakatogawa, Tetsundo; Nishikawa, Hideo; Kawanishi, Kohei; Tsuruto, Chuichi.

    1980-01-01

    Blowdown experiments were carried out in order to clarify pipe reaction forces and jet forces at hypothetical pipe break accident in PWR. The experiments were carried out at the initial pressure of about 70 and 150 kg/cm 2 .G with subcooling temperature of 13 -- 41 0 C. The reaction force has a maximum value just after the rupture in such a manner to attain abruptly to a peak and gradually decreases after that time in proportion to the inner pressure of the pipe. A plane board was used as a target, on which two-phase flow jet impinged vertically. A distribution of pressure on the target is most wide just after break. On the other hand, the pressure has a maximum value after a short period of time from the rupture. (author)

  12. Muscle impingement: MR imaging of a painful complication of osteochondromas

    Energy Technology Data Exchange (ETDEWEB)

    Uri, D.S. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States); Dalinka, M.K. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States); Kneeland, J.B. [Department of Radiology, Hospital of the University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104 (United States)

    1996-10-01

    The purpose of this study was to describe the magnetic resonance (MR) appearance of a newly recognized complication of osteochondromas. Two patients presented with pain and swelling over known osteochondromas. Plain radiographic studies were unrevealing. MR examinations were obtained to characterize the exostoses further and evaluate areas of palpable fullness. Increased signal was present in the muscles on T2-weighted images, which correlated with physical findings and was believed to represent muscle injury due to the osteochondroma. Pain and fullness may result from a number of osteochondroma-related complications, the most worrisome of which is malignant degeneration. Muscular impingement and injury should be considered in the differential diagnosis of pain and swelling in the region of an exostosis. MR imaging allows distinction of this entity, which may be radiographically occult and confused clinically with fracture, bursitis, or malignant degeneration. (orig.). With 2 figs.

  13. Muscle impingement: MR imaging of a painful complication of osteochondromas

    International Nuclear Information System (INIS)

    Uri, D.S.; Dalinka, M.K.; Kneeland, J.B.

    1996-01-01

    The purpose of this study was to describe the magnetic resonance (MR) appearance of a newly recognized complication of osteochondromas. Two patients presented with pain and swelling over known osteochondromas. Plain radiographic studies were unrevealing. MR examinations were obtained to characterize the exostoses further and evaluate areas of palpable fullness. Increased signal was present in the muscles on T2-weighted images, which correlated with physical findings and was believed to represent muscle injury due to the osteochondroma. Pain and fullness may result from a number of osteochondroma-related complications, the most worrisome of which is malignant degeneration. Muscular impingement and injury should be considered in the differential diagnosis of pain and swelling in the region of an exostosis. MR imaging allows distinction of this entity, which may be radiographically occult and confused clinically with fracture, bursitis, or malignant degeneration. (orig.). With 2 figs

  14. Hip arthroscopy with labral repair for femoroacetabular impingement

    DEFF Research Database (Denmark)

    Dippmann, Christian; Thorborg, Kristian; Kraemer, Otto

    2014-01-01

    PURPOSE: The purpose of this study was to examine the progression of clinical outcomes 3, 6 and 12 months after hip arthroscopy with labral repair for femoroacetabular impingement (FAI). METHODS: From May 2009 to December 2011, 87 consecutive patients [55 females (median age 38, range 17-63) and 32...... males (median age 38, range 15-59)] underwent hip arthroscopy and labral repair, by the same experienced surgeon. Standardised, but unstructured, post-operative rehabilitation instructions were provided. Function and pain were evaluated using modified Harris Hip Score (mHHS) and visual analogue scale...... months with no additional changes from 6 to 12 months [22.6 (2.6)-27.9 (2.6), (n.s.)]. CONCLUSIONS: Improvements in function (mHHS) and pain (VAS) were seen in patients after hip arthroscopy with labral repair for FAI at 3, 6, and 12 months. While significant improvements occurred from 3 to 6 months...

  15. Impingement and entrainment: an updated annotated bibliography. Final report

    International Nuclear Information System (INIS)

    Yost, F.E.; Uziel, M.S.

    1981-05-01

    Presented as an annotated bibliography are 1343 references dealing with entrainment and impingement effects on aquatic organisms passing through the cooling systems of thermal power plants. The references were obtained from open literature and from environmental reports and impact statements prepared by or for the electric utility industry. Two earlier bibliographies contain literature from 1950 through 1976. This update contains additional literature acquired since 1976. Topics covered are site-specific field studies at facilities located on lakes, reservoirs, rivers, or estuaries. The studies include special engineering studies, laboratory studies, studies of biological effects, reviews and methodologies, and studies of the mitigation of effects. References are arranged alphabetically by author, and indexes are provided to personal and corporate authors, and to facility, waterbody, and taxonomic names

  16. Vascular endothelial growth factor 121 and 165 in the subacromial bursa are involved in shoulder joint contracture in type II diabetics with rotator cuff disease.

    Science.gov (United States)

    Handa, Akiyoshi; Gotoh, Masafumi; Hamada, Kazutoshi; Yanagisawa, Kazuhiro; Yamazaki, Hitoshi; Nakamura, Masato; Ueyama, Yoshito; Mochida, Joji; Fukuda, Hiroaki

    2003-11-01

    Vascular endothelial growth factor (VEGF) is a glycoprotein that plays an important role in neovascularization and increases vascular permeability. We reported that VEGF is involved in motion pain of patients with rotator cuff disease by causing synovial proliferation in the subacromial bursa (SAB). The present study investigates whether VEGF is also involved in the development of shoulder contracture in diabetics with rotator cuff disease. We examined 67 patients with rotator cuff disease, including 36 with complete cuff tears, 20 with incomplete tears, and 11 without apparent tears (subacromial bursitis). The patients were into groups according to the presence or absence of diabetes (14 type II diabetics and 53 non-diabetics). Specimens of the synovium of the SAB were obtained from all patients during surgery. Expression of the VEGF gene in the synovium of the subacromial bursa was evaluated by using the reverse transcriptase polymerase chain reaction. The VEGF protein was localized by immunohistochemistry, and the number of vessels was evaluated based on CD34 immunoreactivity. The results showed that VEGF mRNA was expressed in significantly more diabetics (100%, 14/14) than in non-diabetics (70%, 37/53) (P=0.0159, Fisher's test). Investigation of VEGF isoform expression revealed VEGF121 in all 14 diabetics and in 37 of the 53 non-diabetics, VEGF165 in 12 of the 14 diabetics and in 21 of the 53 non-diabetics, and VEGF189 in 1 of the 14 diabetics and in 2 of the 53 non-diabetics. No VEGF206 was expressed in either group. VEGF protein was localized in both vascular endothelial cells and synovial lining cells. The mean number of VEGF-positive vessels and the vessel area were also significantly greater in the diabetics (pshoulder joint contracture were more common in the diabetics (P=0.0329 and P=0.073, respectively; Fisher's test). The mean preoperative range of shoulder motion significantly differed in terms of elevation between two groups: 103.8 degrees in

  17. Comparative analysis of arthroscopic debridement in osseous versus soft tissue anterior ankle impingement.

    Science.gov (United States)

    Devgan, Ashish; Rohilla, Rajesh; Tanwar, Milind; Jain, Aditya; Siwach, Karan; Devgan, Radika

    2016-01-01

    Arthroscopic debridement has been a gold standard procedure for anterior ankle impingement, both in cases of osseous and soft tissue impingement. There is sparse literature on comparative outcome with respect to functional results between the two types of impingement post-arthroscopic debridement. Our study included 14 patients diagnosed as cases of anterior ankle impingement on the basis of clinical and radiological examination. They were segregated into two groups (on the basis of cause of impingement (osseous versus soft tissue)). Both groups were treated by arthroscopic debridement. Primary outcome was patient satisfaction, which was assessed by Likert scale and clinical outcomes were measured using AOFAS ankle-hind foot scale, VAS score, range of motion and time to return to pre-injury activity level in both groups. Mean follow-up was of 15 months where eleven patients reported an excellent recovery, two patients had good recovery while one patient reported poor outcome. Mean AOFAS ankle hind foot scale improved from 50.5 preoperatively to 85.71 postoperatively (statistically significant; p value - 0.0001). Mean Likert scale value post-operative was 4.21. VAS score showed significant improvement in patients of both the groups. Range of motion was slightly better in soft tissue impingement type with a relatively shorter time to return to sports or preinjury activity level as compared to osseous impingement group. The patients in both the groups had comparable outcomes with no statistically significant difference with regard to patient satisfaction and clinical outcome.

  18. Shoulder Girdle Muscles Endurance in Subjects with and without Impingement Syndrome

    Directory of Open Access Journals (Sweden)

    Afsoun Nodehi-Moghadam

    2011-07-01

    Full Text Available Objective: Any minimal alteration in performance and coordination of scapular and glenohumeral muscles has the potential to lead to shoulder joint dysfunction. The impingement syndrome has been reported as is the most common diagnosis of shoulder pain. The purpose of this study was to determine whether endurance deficits could be detected in patients with shoulder impingement. Materials & Methods: By convenient sampling 15 patients with impingement syndrome at average of 45.3 years of age and 15 healthy persons (age 45.8 years through a case–control design participated in the study. Endurance of glenohumeral and scapulothoracic muscles were tested with a hand held dynamometer. Independent t–test was used to statistically analyze different groups. Results: Compared to non–impaired subjects, those with impingement syndrome demonstrated a significantly lower endurance of external rotation, scaption and scapular abduction and upward rotation movements (P<0.05. In impingement syndrome patients, the external–to–internal rotator muscles endurance ratio was significantly lower than the control group (P<0.05. Conclusion: The result of the study suggests that endurance deficit of rotator cuff and scapular upward rotator muscles may be an important aspect of the impingement syndrome. Shoulder girdle muscles endurance should be considered in evaluation and physical therapy of impingement syndrome patients.

  19. Cryogenic Impinging Jets Subjected to High Frequency Transverse Acoustic Forcing in a High Pressure Environment

    Science.gov (United States)

    2016-07-27

    impingement sheet – Probably due to a impingement point physically moving Distribution A: Approved for Public Release; Distribution Unlimited. PA# 16333 22...AIAA-92- 0458 30th ASM 7. N. Bremond and E. Villermaux, “Atomization by jet impact”, J. Fluid Mech 2006, vol.549, 273-306 8. W.E. Anderson, H. M. Ryan...Sheets formed by Impinging Jets in High Pressure Environments,” AIAA-2004-3526 40th ASM 11. X. Chen, D. Ma, and V. Yang, “Mechanism Study of Impact Wave

  20. Sampling designs and methods for estimating fish-impingement losses at cooling-water intakes

    International Nuclear Information System (INIS)

    Murarka, I.P.; Bodeau, D.J.

    1977-01-01

    Several systems for estimating fish impingement at power plant cooling-water intakes are compared to determine the most statistically efficient sampling designs and methods. Compared to a simple random sampling scheme the stratified systematic random sampling scheme, the systematic random sampling scheme, and the stratified random sampling scheme yield higher efficiencies and better estimators for the parameters in two models of fish impingement as a time-series process. Mathematical results and illustrative examples of the applications of the sampling schemes to simulated and real data are given. Some sampling designs applicable to fish-impingement studies are presented in appendixes

  1. Prevalence of Cam Morphology in Females with Femoroacetabular Impingement

    Directory of Open Access Journals (Sweden)

    David M Levy

    2015-12-01

    Full Text Available Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. The purpose of this study was to determine the prevalence of cam morphology in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and Cam and pincer are two common morphologies responsible for femoroacetabular impingement. Previous literature has reported that cam deformity is predominantly a male morphology, while being significantly less common in females. Cam morphology is commonly assessed with the alpha angle, measured on radiographs. The purpose of this study was to determine the prevalence of cam morphology utilizing the alpha angle in female subjects diagnosed with symptomatic FAI. All females presenting to the senior author’s clinic diagnosed with symptomatic FAI between December 2006 and January 2013 were retrospectively reviewed. Alpha (α angles were measured on AP (anteroposterior and lateral (Dunn 90°, cross-table lateral, and/or frog-leg lateral plain radiographs by two blinded physicians, and the largest measured angle was used. Using Gosvig et al.’s classification, alpha angle was characterized as (pathologic > 57°, borderline (51-56°, subtle (46-50°, very subtle (43-45°, or normal (≤42°. Three hundred and ninety-one patients (438 hips were analyzed (age 36.2 ± 12.3 years. Among the hips included, 35.6% were normal, 14.6% pathologic, 15.1% borderline, 14.6% subtle, and 20.1% very subtle. There was no correlation between alpha angle and patient age (R = 0.17 or body mass index (BMI (R = 0.05. The intraclass correlation coefficient (ICC for α-angle measurements was 0.84. Sixty-four percent of females in this cohort had an alpha angle > 42°. Subtle cam deformity plays a significant role in

  2. Anterolateral ankle impingement: findings and diagnostic accuracy with ultrasound imaging

    International Nuclear Information System (INIS)

    McCarthy, C.L.; Wilson, D.J.; Coltman, T.P.

    2008-01-01

    The objective was to evaluate the findings and diagnostic accuracy of ultrasound in antero-lateral ankle impingement (ALI) with clinical and arthroscopic correlation. Seventeen elite footballers with chronic ankle pain were referred for ultrasound with a clinical diagnosis of ALI (n = 8) or a control condition (n = 9; lateral mechanical instability, osteochondral defect, intra-articular bodies and osteoarthritis). Ultrasound examination included the antero-lateral gutter for abnormal synovial tissue (synovitic lesion), lateral ligament integrity, tibiotalar joint and osseous spurs of the distal tibia and talus. Ultrasound findings were correlated with subsequent arthroscopic appearance. Ultrasound examination detected a synovitic mass in the antero-lateral gutter in all 8 footballers with clinical ALI (100%) and in 2 patients with a control diagnosis (22%). Arthroscopic correlation of antero-lateral synovitis and fibrosis was present in all 10 cases (100%). The synovitic lesion was seen at ultrasound as a nodular soft tissue mass of mixed echogenicity within the antero-lateral gutter, which extruded anteriorly with manual compression of the distal fibula against the tibia. Increased blood supply was detected using power Doppler imaging in only 1 patient. The synovitic lesion measured >10 mm in its maximum dimension in 7 footballers with clinical ALI and <10 mm in the control group. Additional ultrasound findings in patients with abnormal antero-lateral synovial tissue included an anterior talofibular ligament injury in all patients (n = 10), a tibiotalar joint effusion (n = 6) and osseous spurs (n = 4). Antero-lateral synovitic tissue was accurately identified at ultrasound in the absence of an effusion (n = 4). No synovitic lesion was detected at ultrasound or arthroscopy in the remaining 7 patients with a control diagnosis. Ultrasound is accurate in detecting synovitic lesions within the antero-lateral gutter, demonstrating associated ligamentous injuries and in

  3. Patients who are candidates for subacromial decompression have more pronounced range of motion deficits, but do not differ in self-reported shoulder function, strength or pain compared to non-candidates

    DEFF Research Database (Denmark)

    Witten, Adam; Clausen, Mikkel B; Thorborg, Kristian

    2018-01-01

    -reported shoulder function, shoulder strength, ROM, and pain in patients with SIS considered candidates and non-candidates for subacromial decompression (SAD). METHOD: Self-reported shoulder function (Q-DASH and SPADI), maximum isometric muscle strength in shoulder abduction (Abd-strength) and external rotation (ER...... or non-candidates for SAD based on their consultation with an orthopedic specialist blinded to test results and self-reported shoulder function. All outcomes and age, gender, weight and duration of symptoms were compared using the unpaired t test or Mann-Whitney's U test as appropriate. RESULTS: One.......3 vs. 3.7, p = 0.02, effect size = 0.21). No other differences were found between the groups. CONCLUSION: A decrease in abduction and internal rotation range of motion, and increased pain during maximal abduction strength effort are associated with being considered a candidate for subacromial...

  4. Diagnostic accuracy of clinical tests for the diagnosis of hip femoroacetabular impingement/labral tear

    DEFF Research Database (Denmark)

    Reiman, M P; Goode, A P; Cook, C E

    2015-01-01

    BACKGROUND: Surgery for hip femoroacetabular impingement/acetabular labral tear (FAI/ALT) is exponentially increasing despite lacking investigation of the accuracy of various diagnostic measures. Useful clinical utility of these measures is necessary to support diagnostic imaging and subsequent...

  5. Important clinical descriptors to include in the examination and assessment of patients with femoroacetabular impingement syndrome

    DEFF Research Database (Denmark)

    Reiman, M P; Thorborg, K; Covington, K

    2017-01-01

    PURPOSE: Determine which examination findings are key clinical descriptors of femoroacetabular impingement syndrome (FAIS) through use of an international, multi-disciplinary expert panel. METHODS: A three-round Delphi survey utilizing an international, multi-disciplinary expert panel operationally...

  6. Experimental and Numerical Study of Twin Underexpanded Impinging Jets

    Institute of Scientific and Technical Information of China (English)

    Minoru Yaga; Minoru Okano; Masumi Tamashiro; Kenyu Oyakawa

    2003-01-01

    In this paper, the dual underexpanded impinging jets are experimentally and numerically studied. The experiments were performed by measuring the unsteady and averaged wall static pressures and by visualizing density fields using schlieren method. Numerical calculations were also conducted by solving unsteady three dimensional compressible Navier-Stokes equations with Baldwin-Lomax turbulence model. The main parameters for the dual jets are the non-dimensional distance between the two nozzle centers H/D covering 1.5, 2.0, the nozzle to plate separation L/D 2.0, 3.0,4.0 and 5.0 and the pressure ratio defined by Po/Pb 1.0~6.0, where D is the diameter of each nozzle exit, Po the stagnation pressure and Pb the back pressure. It is found that the agreement between the experiments and the calculations is good. The fountain flow at the middle of the two jets is observed both in the experiments and the calculation. According to FFT analysis of the experiments for the twin jets,relatively low frequency (up to 5 kHz) is dominant for H/D =1.5, L/D =2.0 and pressure ratio Po/Pb =3.0 and 5.0,which is confirmed by the experiments.

  7. Magnetic resonance imaging findings in anterolateral impingement of the ankle

    International Nuclear Information System (INIS)

    Jordan, L.K. III.; Cooperman, A.E.; Helms, C.A.; Speer, K.P.

    2000-01-01

    Objective. To demonstrate the MR imaging findings of anterolateral impingement (ALI) of the ankle.Design and patients. Nine patients with a history of ankle inversion injury and chronic lateral ankle pain were imaged with MR imaging, and the findings correlated with the results of arthroscopy. Three additional patients with clinically suspected ALI of the ankle were also included. Ankle MR imaging studies from 20 control patients in whom ALI was not suspected clinically were examined for similar findings to the patient group.Results. MR imaging findings in the patients with ALI included a soft tissue signal mass in the anterolateral gutter of the ankle in 12 of 12 (100%) cases, corresponding to the synovial hypertrophy and soft tissue mass found at arthroscopy in the nine patients who underwent arthroscopy. Disruption, attenuation, or marked thickening of the anterior talofibular ligament was seen in all cases. Additional findings included signs of synovial hypertrophy elsewhere in the tibiotalar joint in seven of 12 patients (58%) and bony and cartilaginous injuries to the tibiotalar joint in five of 12 (42%). None of the control patients demonstrated MR imaging evidence of a soft tissue mass in the anterolateral gutter.Conclusions. ALI of the ankle is a common cause for chronic lateral ankle pain. It has been well described in the orthopedic literature but its imaging findings have not been clearly elucidated. The MR imaging findings, along with the appropriate clinical history, can be used to direct arthroscopic examination and subsequent debridement. (orig.)

  8. Impaired hip muscle strength in patients with femoroacetabular impingement syndrome.

    Science.gov (United States)

    Kierkegaard, Signe; Mechlenburg, Inger; Lund, Bent; Søballe, Kjeld; Dalgas, Ulrik

    2017-12-01

    Patients with femoroacetabular impingement (FAI) experience hip pain as well as decreased function and lowered quality of life. The aim was to compare maximal isometric and isokinetic muscle strength (MVC) during hip flexion and extension and rate of force development (RFD) during extension between patients with FAI and a matched reference group. Secondary, the aim was to compare patient hips and subgroups defined by gender and age as well as to investigate associations between hip muscle strength and self-reported outcomes. Design Cross-sectional, comparative study Methods Sixty patients (36±9 years, 63% females) and 30 age and gender matched reference persons underwent MVC tests in an isokinetic dynamometer. During hip flexion and extension, patients' affected hip showed a strength deficit of 15-21% (phip of the patients was significantly weaker than their contralateral hip. RFD was significantly decreased for both patient hips compared to the reference group (phip muscle strength. Patients with FAI demonstrate decreased hip flexion and extension strength when compared to (1) reference persons and (2) their contralateral hip. There seems to be a gender specific affection which should be investigated further and addressed when planning training protocols. Furthermore, self-reported measures were associated with isometric muscle strength, which underlines the clinical importance of the reduced muscle strength. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

  9. [Effectiveness of physiotherapy on painful shoulder impingement syndrome].

    Science.gov (United States)

    Gomora-García, Mónica; Rojano-Mejía, David; Solis-Hernández, José Luis; Escamilla-Chávez, Carolina

    2016-01-01

    Painful shoulder impingement syndrome is one of the first reasons for care in rehabilitation centres. As the evidence regarding the effectiveness of physical measures as adjuvant treatment is limited, the aim of this study was to determine the effectiveness of physiotherapy on shoulder pain. A retrospective and analytical study was conducted using the medical records of patients with shoulder pain who attended in a rehabilitation centre from October 2010 to September 2011. The demographic and clinical data were collected, and the clinical improvement was determined as: complete, incomplete, or no improvement. Chi squared was used to determine whether there were differences between the different modalities of physiotherapy, as well as the level of improvement. The study included a total of 181 patients, with a mean age of 54.3 years, and a mean of 4.6 months of onset of pain. The physiotherapy treatments included: warm compresses plus interferential current (60.2%), and warm compresses plus ultrasound (17.1%). Just over half (53.6%) obtained a moderate recovery, 36.4% slight improvement, and 9.9% no improvement. No significant differences were found between the different forms of therapy. The supervised rehabilitation program consists of 9 sessions of physiotherapy. A functional improvement of 90% was obtained, without finding any statistical differences between the therapies used. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

  10. Herniation pits and their renaissance in association with femoroacetabular impingement

    International Nuclear Information System (INIS)

    Panzer, Stephonie; Augat, P.; Paracelsus Univ. Salzburg; Scheidler, J.

    2010-01-01

    Hernitation pits (HPs) of the femoral neck were first described in 1982. The purpose of this paper is to summarize the information concerning HPs published since then and to show their association with the diagnosis of femoroacetabular impingement (FAI) which has occurred within the last years. HPs are predominantly located at the anterior-superior femoral neck with a typical radiological appearance, which makes it possible to differentiate them from the numerous differential diagnoses mentioned. In the early publications HPs were described as a separate entity, while recent studies increasingly assign them to intra-osseous ganglia. In contrast to the early publications depicting HPs as an incidental finding, they are currently mainly mentioned in association with FAI and at the same time are partly considered to be a radiological indicator of FAI. In summary, HPs should always be recognized and documented because they may contribute to the diagnosis of FAI which is essential for preventing or delaying osteoarthritis of the hip joint in the early stage. (orig.)

  11. Hip arthroscopy versus open surgical dislocation for femoroacetabular impingement

    Science.gov (United States)

    Zhang, Dagang; Chen, Long; Wang, Guanglin

    2016-01-01

    Abstract Background: This meta-analysis aims to evaluate the efficacy and safety of hip arthroscopy versus open surgical dislocation for treating femoroacetabular impingement (FAI) through published clinical trials. Methods: We conducted a comprehensive literature search using PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials databases for relevant studies on hip arthroscopy and open surgical dislocation as treatment options for FAI. Results: Compared with open surgical dislocation, hip arthroscopy resulted in significantly higher Nonarthritic Hip Scores (NAHS) at 3- and 12-month follow-ups, a significant improvement in NAHS from preoperation to 3 months postoperation, and a significantly lower reoperation rate. Open surgical dislocation resulted in a significantly improved alpha angle by the Dunn view in patients with cam osteoplasty from preoperation to postoperation, compared with hip arthroscopy. This meta-analysis demonstrated no significant differences in the modified Harris Hip Score, Hip Outcome Score-Activities of Daily Living, or Hip Outcome Score-Sport Specific Subscale at 12 months of follow-up, or in complications (including nerve damage, wound infection, and wound dehiscence). Conclusion: Hip arthroscopy resulted in higher NAHS and lower reoperation rates, but had less improvement in alpha angle in patients with cam osteoplasty, than open surgical dislocation. PMID:27741133

  12. A Novel Association between Femoroacetabular Impingement and Anterior Knee Pain.

    Science.gov (United States)

    Sanchis-Alfonso, Vicente; Tey, Marc; Monllau, Joan Carles

    2015-01-01

    Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP) patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI) resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS), knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS). Results. The VAS knee pain score and VAS hip pain score had a significant improvement postoperatively. At final follow-up, there was significant improvement in all functional scores (Kujala score and NAHS). Conclusion. Our finding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment.

  13. A Novel Association between Femoroacetabular Impingement and Anterior Knee Pain

    Directory of Open Access Journals (Sweden)

    Vicente Sanchis-Alfonso

    2015-01-01

    Full Text Available Background. For a long time it has been accepted that the main problem in the anterior knee pain (AKP patient is in the patella. Currently, literature supports the link between abnormal hip function and AKP. Objective. Our objective is to investigate if Cam femoroacetabular impingement (FAI resolution is related to the outcome in pain and disability in patients with chronic AKP recalcitrant to conservative treatment associated with Cam FAI. Material and Methods. A retrospective study on 7 patients with chronic AKP associated with FAI type Cam was performed. Knee and hip pain were measured with the visual analogue scale (VAS, knee disability with the Kujala scale, and hip disability with the Nonarthritic Hip Score (NAHS. Results. The VAS knee pain score and VAS hip pain score had a significant improvement postoperatively. At final follow-up, there was significant improvement in all functional scores (Kujala score and NAHS. Conclusion. Our finding supports the link between Cam FAI and AKP in some young patients. Assessment of Cam FAI should be considered as a part of the physical examination of patients with AKP, mainly in cases with pain recalcitrant to conservative treatment.

  14. Experiments and analyses on melt jet impingement during severe accidents

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Green, J.A.; Dinh, T.N.; Dong, W.

    1997-01-01

    Relocation of melt from the core region, during a nuclear reactor severe accident, presents the potential for erosion of the reactor pressure vessel (RPV) wall as a result of melt jet impingement. The extent of vessel erosion will depend upon a variety of parameters, including jet diameter, velocity, composition, superheat, angle of inclination, and the presence of an overlying water or melt pool. Experiments have been conducted at the Royal Institute of Technology Division of Nuclear Power Safety (RIT/NPS) which employ a variety of melt and pressure vessel simulant materials, such as water, salt-ice, Cerrobend alloy and molten salt. These experiments have revealed that the erosion depth of the vessel simulant in the jet stagnation zone can be adequately predicted by the Saito correlation, which is based on turbulent heat transfer, while initial erosion rates are seen to be in line with the laminar-stagnation-zone model. A transition between the laminar and turbulent regimes was realized in most cases and is attributed to the roughness of the surface in the eroded cavity formed

  15. Comparison of methods for detection and enumeration of airborne microorganisms collected by liquid impingement.

    OpenAIRE

    Terzieva, S; Donnelly, J; Ulevicius, V; Grinshpun, S A; Willeke, K; Stelma, G N; Brenner, K P

    1996-01-01

    Bacterial agents and cell components can be spread as bioaerosols, producing infections and asthmatic problems. This study compares four methods for the detection and enumeration of aerosolized bacteria collected in an AGI-30 impinger. Changes in the total and viable concentrations of Pseudomonas fluorescens in the collection fluid with respect to time of impingement were determined. Two direct microscopic methods (acridine orange and BacLight) and aerodynamic aerosol-size spectrometry (Aeros...

  16. Computed tomography assessment of hip joints in asymptomatic individuals in relation to femoroacetabular impingement.

    Science.gov (United States)

    Kang, Alan C L; Gooding, Andrew J; Coates, Mark H; Goh, Tony D; Armour, Paul; Rietveld, John

    2010-06-01

    Femoroacetabular impingement has become a well-recognized entity predisposing to acetabular labral tears and chondral damage, and subsequently development of osteoarthritis of the hip joint. In the authors' experience, it is common to see bony abnormalities predisposing to femoroacetabular impingement in the contralateral asymptomatic hips in patients with unilateral femoroacetabular impingement. This study was undertaken to investigate the prevalence of bony abnormalities predisposing to femoroacetabular impingement in asymptomatic individuals without exposing study participants to unnecessary radiation. Cross-sectional study; Level of evidence, 4. Fifty individuals (100 hip joints), ranging from 15 to 40 years of age, who were seen at a local hospital between March and August 2008 with abdominal trauma or nonspecific abdominal pain in whom abdominal computed tomography was performed to aid diagnosis were prospectively studied. These patients were not known to have any history of hip-related problems. Raw data from the abdominal computed tomography scan, performed on a 64-slice multidetector computed tomography scanner, were reformatted using bone algorithm into several different planes. Several measurements and observations of the hip joints were made in relation to femoroacetabular impingement. The 100 hip joints from 50 patients with no history of hip problems demonstrated that 39% of the joints (31% of female, 48% of male joints) have at least 1 morphologic aspect predisposing to femoroacetabular impingement. The majority (66% to 100% ) of the findings were bilateral; 33% of female and 52% of male asymptomatic participants in our study had at least 1 predisposing factor for femoroacetabular impingement in 1 or both of their hip joints. Based on the data collected from this study, the acetabular crossover sign had a 71% sensitivity and 88% specificity for detecting acetabular retroversion. Nonquantitative assessment of the femoral head at the anterior

  17. Effects of water chemistry on flow accelerated corrosion and liquid droplet impingement

    International Nuclear Information System (INIS)

    Uchida, Shunsuke; Naitoh, Masanori; Okada, Hidetoshi; Uehara, Yasushi; Koshizuka, Seiichi; Lister, Derek H.

    2009-01-01

    Overlapping effects of flow dynamics and corrosion are important issues to determine reliability and lifetime of major structures and components in light water reactor plants. Flow accelerated corrosion (FAC) and liquid droplet impingement (LDI) are typical phenomena due to both interactions. In order to evaluation local wall thinning due to FAC and LDI, 6 step evaluation procedures have been proposed. (1) Flow pattern along the flow path was obtained with 1D computational flow dynamics (CFD) codes, (2) Corrosive conditions, e.g., oxygen concentration along the flow path were calculated with a hydrazine oxygen reaction code for FAC evaluation, while flow pattern of liquid droplets in high velocity steam and possibility of their collision to pipe inner surface were evaluated for LDI evaluation. (3) Mass transfer coefficient at the structure surface was calculated with 3D CFD codes for FAC evaluation, while frequency of oxide film rupture due to droplet collision was calculated for LDI evaluation. (4) High risk zones for FAC/LDI occurrence were evaluated by coupling major parameters, and then, (5) Wall thinning rates were calculated with the coupled model of static electrochemical analysis and dynamic double oxide layer analysis at the identified high FAC/LDI risk zone. (author)

  18. Numerical investigation of a vortex ring impinging on a coaxial aperture

    Science.gov (United States)

    Hu, Jiacheng; Peterson, Sean D.

    2017-11-01

    Recent advancements in smart materials have sparked an interest in the development of small scale fluidic energy harvesters for powering distributed applications in aquatic environments, where coherent vortex structures are prevalent. Thus, it is crucial to investigate the interaction of viscous vortices in the proximity of a thin plate (a common harvester configuration). Hence, the present study systematically examines the interaction of a vortex ring impinging on an infinitesimally thin wall with a coaxially aligned annular aperture. The rigid aperture serves as an axisymmetric counterpart of the thin plate, and the vortex ring represents a typical coherent vortex structure. The results indicate that the vortex dynamics can be categorized into two regimes based on the aperture to ring radius ratio (Rr). The rebound regime (Rr = 0.9 , and an increase in the vortex ring impulse is observed for 1.0 energy harvesting strategy in vortex impact configurations. This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Grant (RGPIN-05778) and Alexander Graham Bell Canada Graduate Scholarship (CGS-D).

  19. A simplified analog for a rotorcraft-in-ground-effect flow using a forced impinging jet

    Science.gov (United States)

    Geiser, Jayson; Kiger, Ken

    2010-11-01

    The phenomenon of rotorcraft brown-out is defined as the intense suspension and re-ingestion of sand during the take-off and landing of a rotor-lifted aircraft. To mitigate the problem of rotorcraft brown-out, the non-equilibrium sediment suspension process that occurs within a typical rotorcraft wake must be understood. We attempt to understand the most basic aspects of this complex flow through the use of an axisymmetric forced impinging jet. While this flow neglects the swirl component associated with a rotorcraft, it does reproduce the typical coherent vortex structures, and permits their repeatable generation within an axisymmetric mean stagnation flow. The goal of the current work is to determine the forcing conditions that produce isolated, but intense and repeatable structures that can be followed through their interaction with the wall boundary. Stereo PIV imaging is applied to detail the breakdown of a vortex ring in the wall jet zone. The secondary vortex generation and decay are observed experimentally with 3-D vector fields, and their results are interpreted with respect to their significance in the context of sediment mobilization.

  20. Hydrodynamics and PIV study in the impingement zone formed by a droplet train

    Science.gov (United States)

    Kanjirakat, Anoop; Sadr, Reza; Zhang, Taolue; Muthusamy, Jayaveera; Alvarado, Jorge; Texas A; M University at Qatar Collaboration; Texas A; M University College Station Collaboration

    2016-11-01

    Droplet impingement is encountered in numerous technical applications, such as ink jet printing, spray cooling, and fuel injection in internal combustion engines. Even though many studies in droplet impingement were conducted in past, not many have measured the near-wall velocities in the droplet impingement zone. With the goal of gaining a better understanding of the hydrodynamics in the impingement zone, well-controlled experiments are performed in combination with micro-PIV measurements and numerical simulations. Hydrodynamics of HFE-7100 droplets generated using a piezoelectric droplet generator, impinging on a pre-wetted surface is investigated. Micro-PIV studies in the high-velocity impingement zone are performed using one-micron meter fluorescent particles dispersed in HFE-7100 along with the double exposed images. Three-dimensional and 2D-axisymmetric numerical modeling for a transient droplet crown development is performed. The interface between the gas and the liquid is modeled using a Volume of Fluid (VOF) method. Numerical simulation results obtained are observed to be in good agreement with that of the experimental observations. Supported by National Priority Research Program (NPRP) of Qatar National Research Fund (QNRF), Grant No.: NPRP 6-1304-2-525.

  1. Impingement and entrainment of fishes at the Savannah River Plant: an NPDES 316b demonstration

    International Nuclear Information System (INIS)

    McFarlane, R.W.; Frietsche, R.F.; Miracle, R.D.

    1978-02-01

    Environmental impacts of the Savannah River Plant's withdrawal of Savannah River water include impingement of juvenile and adult fish on trash removal screens, and entrainment of planktonic fish eggs and larval fish into the pumping system. The Savannah River Plant (SRP) has the capacity to pump 3.6 million cubic meters of water per day--25% of the minimal river discharge--for cooling and other purposes. Present removal is 7% of the actual river discharge. In the river and intake canals reside sixty-nine species of fishes. The species composition of the resident fish community of the intake canals is similar to the species composition in the river, but different in relative species abundance. The dominant sunfishes tend to reside in the canals for long periods and seldom go from canal to canal. The fish impingement rate at the plant ranks very low in comparison with electric power plants on inland waters. Thirty-five species of fishes were impinged during 1977. The average impingement rate of 7.3 fish per day extrapolates to 2,680 fish per year. No single species comprised more than 10% of the sample. The most commonly impinged species were bluespotted sunfish, warmouth, channel catfish, and yellow perch. The relative abundance of those species impinged deviates from their relative abundance in the canal fish population

  2. Reliability of impingement sampling designs: An example from the Indian Point station

    International Nuclear Information System (INIS)

    Mattson, M.T.; Waxman, J.B.; Watson, D.A.

    1988-01-01

    A 4-year data base (1976-1979) of daily fish impingement counts at the Indian Point electric power station on the Hudson River was used to compare the precision and reliability of three random-sampling designs: (1) simple random, (2) seasonally stratified, and (3) empirically stratified. The precision of daily impingement estimates improved logarithmically for each design as more days in the year were sampled. Simple random sampling was the least, and empirically stratified sampling was the most precise design, and the difference in precision between the two stratified designs was small. Computer-simulated sampling was used to estimate the reliability of the two stratified-random-sampling designs. A seasonally stratified sampling design was selected as the most appropriate reduced-sampling program for Indian Point station because: (1) reasonably precise and reliable impingement estimates were obtained using this design for all species combined and for eight common Hudson River fish by sampling only 30% of the days in a year (110 d); and (2) seasonal strata may be more precise and reliable than empirical strata if future changes in annual impingement patterns occur. The seasonally stratified design applied to the 1976-1983 Indian Point impingement data showed that selection of sampling dates based on daily species-specific impingement variability gave results that were more precise, but not more consistently reliable, than sampling allocations based on the variability of all fish species combined. 14 refs., 1 fig., 6 tabs

  3. Effect of Battlefield Acupuncture and Physical Therapy Versus Physical Therapy Alone After Shoulder Surgery

    Science.gov (United States)

    2018-05-14

    Opioid Use; Pain, Postoperative; SLAP Lesion; Bankart Lesion; Subacromial Impingement Syndrome; Rotator Cuff Tear; Glenohumeral Dislocation; Glenohumeral Subluxation; Hill Sach Lesion; Bony Bankart Lesion; Acromioclavicular Separation

  4. Methodological quality of systematic reviews addressing femoroacetabular impingement.

    Science.gov (United States)

    Kowalczuk, Marcin; Adamich, John; Simunovic, Nicole; Farrokhyar, Forough; Ayeni, Olufemi R

    2015-09-01

    As the body of literature on femoroacetabular impingement (FAI) continues to grow, clinicians turn to systematic reviews to remain current with the best available evidence. The quality of systematic reviews in the FAI literature is currently unknown. The goal of this study was to assess the quality of the reporting of systematic reviews addressing FAI over the last 11 years (2003-2014) and to identify the specific methodological shortcomings and strengths. A search of the electronic databases, MEDLINE, EMBASE and PubMed, was performed to identify relevant systematic reviews. Methodological quality was assessed by two reviewers using the revised assessment of multiple systematic reviews (R-AMSTAR) scoring tool. An intraclass correlation coefficient (ICC) with 95 % confidence intervals (CI) was used to determine agreement between reviewers on R-AMSTAR quality scores. A total of 22 systematic reviews were assessed for methodological quality. The mean consensus R-AMSTAR score across all studies was 26.7 out of 40.0, indicating fair methodological quality. An ICC of 0.931, 95 % CI 0.843-0.971 indicated excellent agreement between reviewers during the scoring process. The systematic reviews addressing FAI are generally of fair methodological quality. Use of tools such as the R-AMSTAR score or PRISMA guidelines while designing future systematic reviews can assist in eliminating methodological shortcomings identified in this review. These shortcomings need to be kept in mind by clinicians when applying the current literature to their patient populations and making treatment decisions. Systematic reviews of highest methodological quality should be used by clinicians when possible to answer clinical questions.

  5. A computational study of highly viscous impinging jets

    International Nuclear Information System (INIS)

    Silva, M.W.

    1998-11-01

    Two commercially-available computational fluid dynamics codes, FIDAP (Fluent, Inc., Lebanon, NH) and FLOW-3D (Flow Science, Inc., Los Alamos, NM), were used to simulate the landing region of jets of highly viscous fluids impinging on flat surfaces. The volume-of-fluid method was combined with finite difference and finite element approaches to predict the jet behavior. Several computational models with varying degrees of physical realism were developed, and the results were compared with experimental observations. In experiments, the jet exhibited several complex behaviors. As soon as it exited the nozzle, the jet began to neck down and become narrower. When it impacted the solid surface, the jet developed an instability near the impact point and buckled to the side. This buckling became a spiraling motion, and the jet spiraled about the impact point. As the jet spiraled around, a cone-shaped pile was build up which eventually became unstable and slumped to the side. While all of these behaviors were occurring, air bubbles, or voids, were being entrapped in the fluid pool. The results obtained from the FLOW-3D models more closely matched the behavior of real jets than the results obtained from /the FIDAP models. Most of the FLOW-3D models predicted all of the significant jet behaviors observed in experiments: necking, buckling, spiraling, slumping, and void entrapment. All of the FIDAP models predicted that the jet would buckle relatively far from the point of impact, whereas the experimentally observed jet behavior indicates that the jets buckle much nearer the impact point. Furthermore, it was shown that FIDAP is incapable of incorporating heat transfer effects into the model, making it unsuitable for this work

  6. Patient Satisfaction Reporting for the Treatment of Femoroacetabular Impingement.

    Science.gov (United States)

    Kahlenberg, Cynthia A; Nwachukwu, Benedict U; Schairer, William W; McCormick, Frank; Ranawat, Anil S

    2016-08-01

    The purpose of this study was to evaluate how patient satisfaction after surgical femoroacetabular impingement (FAI) treatment is measured and reported in the current evidence base. A review of the MEDLINE database was performed. Clinical outcome studies of FAI that reported a measure of patient satisfaction were included. Patient demographics, clinical outcome scores, and patient satisfaction measures were extracted. The NewCastle Ottawa Scale (NOS) was used to grade quality. Statistical analysis was primarily descriptive. Twenty-six studies met inclusion criteria; the mean NOS score among included studies was 5.7. Most studies were level 3 or 4 (n = 25, 96.1%). A 0 to 10 numeric scale, described by some studies as a visual analog scale, was the most commonly used method to assess satisfaction (n = 21; 80.8%), and mean reported scores ranged from 6.8 to 9.2 out of 10. Four studies (15.4%) used an ordinal scale, and 1 study (3.8%) used willingness to undergo surgery again as the measure of satisfaction. None of the included studies assessed preoperative satisfaction or patient expectation. Pooled cohort analysis was limited by significant overlapping study populations. Predictors of patients' satisfaction identified in included studies were presence of arthritis and postoperative outcome scores. Patient satisfaction was not uniformly assessed in the literature. Most studies used a 0- to 10-point satisfaction scale, but none distinguished between the process of care and the outcome of care. Although satisfaction scores were generally high, the quality of the methodologies in the studies that reported satisfaction was low, and the studies likely included overlapping patient populations. More work needs to be done to develop standardized ways for assessing patient satisfaction after arthroscopic hip surgery and other procedures in orthopaedic sports medicine. Level III, systematic review of Level III studies. Copyright © 2016 Arthroscopy Association of North

  7. Surgical criteria for femoroacetabular impingement syndrome: a scoping review.

    Science.gov (United States)

    Peters, Scott; Laing, Alisha; Emerson, Courtney; Mutchler, Kelsey; Joyce, Thomas; Thorborg, Kristian; Hölmich, Per; Reiman, Michael

    2017-11-01

    The purpose of this review was to analyse and report criteria used for open and arthroscopic surgical treatment of femoroacetabular impingement syndrome (FAIS). A librarian-assisted computer search of Medline, CINAHL and Embase for studies related to criterion for FAIS surgery was used in this study. Inclusion criteria included studies with the primary purpose of surgery or surgical outcomes for treatment of FAIS with and without labral tear, and reporting criteria for FAIS surgery. Diagnostic imaging was a criterion for surgery in 92% of the included studies, with alpha angle the most frequently reported (68% of studies) criterion. Reporting of symptoms was a criterion for surgery in 75%, and special tests a criterion in 70% of studies. Range-of-motion limitations were only a required criterion in 30%, only 12% of studies required intra-articular injection and 44% of studies described previously failed treatment (non-surgical or physiotherapist-led rehabilitation) as a criterion for surgery. Only 56% of included studies utilised the combination of symptoms, clinical signs and diagnostic imaging combined for diagnosis of FAIS as suggested by the Warwick Agreement on FAIS meeting. Diagnostic imaging evidence of FAIS was the most commonly reported criterion for surgery. Only 56% of included studies utilised the combination of symptoms, clinical signs and diagnostic imaging for diagnosis of FAIS as suggested by the Warwick Agreement on FAIS meeting, and only 44% of studies had failed non-surgical treatment (and 18% a failed trial of physiotherapy) as a criterion for surgery. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. A computational study of highly viscous impinging jets

    Energy Technology Data Exchange (ETDEWEB)

    Silva, M.W. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering

    1998-11-01

    Two commercially-available computational fluid dynamics codes, FIDAP (Fluent, Inc., Lebanon, NH) and FLOW-3D (Flow Science, Inc., Los Alamos, NM), were used to simulate the landing region of jets of highly viscous fluids impinging on flat surfaces. The volume-of-fluid method was combined with finite difference and finite element approaches to predict the jet behavior. Several computational models with varying degrees of physical realism were developed, and the results were compared with experimental observations. In experiments, the jet exhibited several complex behaviors. As soon as it exited the nozzle, the jet began to neck down and become narrower. When it impacted the solid surface, the jet developed an instability near the impact point and buckled to the side. This buckling became a spiraling motion, and the jet spiraled about the impact point. As the jet spiraled around, a cone-shaped pile was build up which eventually became unstable and slumped to the side. While all of these behaviors were occurring, air bubbles, or voids, were being entrapped in the fluid pool. The results obtained from the FLOW-3D models more closely matched the behavior of real jets than the results obtained from /the FIDAP models. Most of the FLOW-3D models predicted all of the significant jet behaviors observed in experiments: necking, buckling, spiraling, slumping, and void entrapment. All of the FIDAP models predicted that the jet would buckle relatively far from the point of impact, whereas the experimentally observed jet behavior indicates that the jets buckle much nearer the impact point. Furthermore, it was shown that FIDAP is incapable of incorporating heat transfer effects into the model, making it unsuitable for this work.

  9. Radiographic evidence of femoroacetabular impingement in athletes with athletic pubalgia.

    Science.gov (United States)

    Economopoulos, Kostas J; Milewski, Matthew D; Hanks, John B; Hart, Joseph M; Diduch, David R

    2014-03-01

    Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. We hypothesized that patients with athletic pubalgia would have a high prevalence of underlying FAI. Case series. Level 4. A retrospective review of all patients evaluated at our institution with athletic pubalgia who underwent surgical treatment (ie, for sports hernia) from 1999 to 2011 was performed. The radiographs of patients with athletic pubalgia were reviewed for radiographic signs of FAI. Alpha angles were measured using frog-leg lateral radiographs. Pincer lesions were identified by measuring the lateral center-edge angle and identifying the presence of a "crossover" sign on anteroposterior radiographs. Phone follow-up was performed 2 years or more after the initial sports hernia surgery to evaluate recurrent symptoms. Forty-three patients underwent 56 athletic pubalgia surgeries. Radiographic evidence of FAI was identified in at least 1 hip in 37 of 43 patients (86%). Cam lesions were identified in 83.7% of the population; the alpha angle averaged 66.7° ± 17.9° for all hips. Pincer lesions were present in 28% of the hips. Eight patients had recurrent groin pain, 3 patients had revision athletic pubalgia surgery, and 1 had hip arthroscopy. The study demonstrates a high prevalence of radiographic FAI in patients with athletic pubalgia. Underlying FAI may be a cause of continued groin pain after athletic pubalgia surgery. Patients with athletic pubalgia should be evaluated closely for FAI.

  10. Water Impingement Erosion of Deep-Rolled Ti64

    Directory of Open Access Journals (Sweden)

    Dina Ma

    2015-08-01

    Full Text Available In this work, the Liquid Impingement Erosion (LIE performances of deep-rolling (DR treated and non-treated Ti64 were investigated. Various erosion stages, from the incubation to the terminal erosion stages, could be observed. A full factorial design of experiments was used to study the effect of DR process parameters (Feed Rate, Spindle Velocity, Number of Passes, Pressure on the residual stress distribution, microhardness and surface roughness of the treated Ti64 specimens. The DR-treated Ti64 specimens exhibited improved surface microhardness, surface roughness, and large magnitude of compressive residual stresses, which were attributed to the amount of cold work induced by the DR process. Although DR improved the mechanical properties of the Ti64, the results showed that the treatment has little or no effect on the LIE performance of Ti64 but different damage modes were observed in these two cases. Evolution of the erosion stages was described based on water-hammer pressure, stress waves, radial wall jetting, and hydraulic penetration modes. The initial erosion stages were mainly influenced by water-hammer pressure and stress waves, whereas the intermediate erosion stages were influenced by the combination of the four modes together. The final erosion stages contain the four modes, however the erosion was greatly driven by the radial jetting and hydraulic penetration modes, where more material was removed. The failure mechanism of the final stages of the LIE test of both DR-treated and non-treated Ti64 was characterized as fatigue fracture. However, a brittle fracture behavior was observed in the initial and intermediate erosion stages of the DR-treated Ti64, whereas a ductile fracture behavior was observed in the non-treated Ti64. This was concluded from the micrographs of the LIE damage through different erosion stages.

  11. Droplet impaction on solid surfaces exposed to impinging jet fires

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, Zia

    2005-12-15

    The thermal response of hot surfaces exposed to impinging jet fire and subsequent impacting water droplets is investigated. The research was done mainly experimentally by utilizing three different concepts. This included experiments on a laboratory scale steel plate and large outdoor fire tests with a quadratic steel channel and steel plates. Besides the horizontal jet flame itself was characterized in a comprehensive study. As a comparative study, the last three types of the experiment were additionally modeled by the CFD-code Kameleon FireEx for validation of results. The purpose of the experiments done on bench scale steel plate (L x W x T : 300 x 200 x 8 mm) was mainly to map data on wetting temperature, water droplet size, droplet impingement angle, and droplet velocity prior to large scale jet fire tests. The droplet release angle normal to hot surface gives best cooling effect, when the surface is oriented in upright position. The partial wetting begins at about 165 degrees C. When the surface is positioned in horizontal plane, the droplet of about 5 mm in diameter wets the hot surface partially at around 240-250 degrees C within an impaction distance of 20 cm. At about 150 degrees C, the droplet is entirely attached to the surface with almost zero contact angle, and cools down the solid at a critical heat flux equivalent to 1750 kW/m{sup 2}. The cooling effectiveness is about 8 % with a Weber number of 68. Although in the event of horizontal channel (L x W x T : 1000 x 200 x 8 mm) water droplets were not applied, however, the knowledge gained with jet fire tests gave valuable information about temperature progress in solids (steels and insulation) and their response to impinging jet fire during long duration experiments. The temperature of the insulated area of the channel keeps 200 degrees C below that of the exposed surface, as long as the insulation material remained intact. Upon long test fire durations, the insulation either burns or degrades despite

  12. Parametric Study of Swept Impinging Oblique Shock/Boundary Layer Interactions

    Science.gov (United States)

    Doehrmann, Adam; Threadgill, James; Little, Jesse

    2017-11-01

    Modern high-speed vehicles have increasingly complex 3D geometries featuring: surface curvature, variable aspect ratio inlet ducts and swept bodies. Such distortion to the flow field necessitates a further understanding of swept 3D Shock/Boundary Layer Interactions (SBLIs), where various regimes of spanwise interaction development have been observed. A parametric experimental study of swept oblique impinging SBLIs has been conducted comparing cylindrical and conical interaction structures to that of swept compression ramps in previous work. This investigation examines five shock generators with 2D deflection of θ = 12 .5° and varying degrees of sweep (ψ = 10 .0° , 15 .0° , 22 .5° , 30 .0° , 40 .0°), with an incoming turbulent flow at Mach 2.3 and 3.0. Parametric characterization of surface oil-flow visualizations has shown that the inception length of the interaction follows a similar trend to that seen in swept compression ramps as sweep is varied, namely that it increases as sweep approaches a critical angle. However, this criteria disagrees with direct observations of separation and reattachment angles. Similarities in mean pressures profiles have also been assessed and analyzed with respect to the onset of a cylindrical/conical interaction. Supported by the Air Force Office of Scientific Research (FA9550-15-1-0430).

  13. A computational study of the impingement region of an unsteady subsonic jet

    Science.gov (United States)

    Jalamani, Zakaria A.; Nakamura, Shoichiro; Van Dalsem, William R.

    1990-01-01

    Vertical/Short Take-Off and Landing (V/STOL) aircraft may encounter operating difficulties while hovering near the ground. Lift loss, hot gas and debris ingestion, and landing surface damage are some of the potential problems which can result from the interaction of the propulsive jets with the airframe and ground. The purpose of the present work is to develop a detailed understanding of a flowfield, a jet exiting from a flat plate impacting a ground plane, that contains much of the essential physics of the complex flows encountered by V/STOL aircraft in hover. To achieve this, a high-resolution time-accurate numerical simulation of the impinging jet flow was performed. The numerical simulation is based on the solution of the laminar compressible Navier-Stokes equations using the Beam-Warming algorithm. Complex start-up and periodic jet and jet-induced vortex structures were captured, including the formation of primary and secondary jet-induced vortices and wall-jet separation. The formation and development of these phenomena are supported by experimental measurements and smoke visualization. Results are compared with appropriate experiments.

  14. Analysis of composite hydrogen storage cylinders subjected to localized flame impingements

    Energy Technology Data Exchange (ETDEWEB)

    Hu, J.; Chen, J.; Sundararaman, S.; Chandrashekhara, K. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, Rolla, MO 65409 (United States); Chernicoff, William [US Department of Transportation, Washington, DC 20509 (United States)

    2008-06-15

    A comprehensive non-linear finite element model is developed for predicting the behavior of composite hydrogen storage cylinders subjected to high pressure and localized flame impingements. The model is formulated in an axi-symmetric coordinate system and incorporates with various sub-models to describe the behavior of the composite cylinder under extreme thermo-mechanical loadings. A heat transfer sub-model is employed to predict the temperature evolution of the composite cylinder wall and accounts for heat transport due to decomposition and mass loss. A composite decomposition sub-model described by Arrhenius's law is implemented to predict the residual resin content of thermal damaged area. A sub-model for material degradation is implemented to account for the loss of mechanical properties. A progressive failure model is adopted to detect various types of mechanical failure. These sub-models are implemented in ABAQUS commercial finite element code using user subroutines. Numerical results are presented for thermal damage, residual properties and profile of resin content in the cylinder. The developed model provides a useful tool for safe design and structural assessment of high pressure composite hydrogen storage cylinders. (author)

  15. Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID

    Energy Technology Data Exchange (ETDEWEB)

    Wanzenboeck, H.D.; Hochleitner, G.; Mika, J.; Shawrav, M.M.; Gavagnin, M.; Bertagnolli, E. [Vienna University of Technology, Institute for Solid State Electronics, Vienna (Austria)

    2014-12-15

    During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-μm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID. (orig.)

  16. Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID

    International Nuclear Information System (INIS)

    Wanzenboeck, H.D.; Hochleitner, G.; Mika, J.; Shawrav, M.M.; Gavagnin, M.; Bertagnolli, E.

    2014-01-01

    During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-μm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID. (orig.)

  17. Mapping of local argon impingement on a virtual surface: an insight for gas injection during FEBID

    Science.gov (United States)

    Wanzenboeck, H. D.; Hochleitner, G.; Mika, J.; Shawrav, M. M.; Gavagnin, M.; Bertagnolli, E.

    2014-12-01

    During the last decades, focused electron beam induced deposition (FEBID) has become a successful approach for direct-write fabrication of nanodevices. Such a deposition technique relies on the precursor supply to the sample surface which is typically accomplished by a gas injection system using a tube-shaped injector nozzle. This precursor injection strategy implies a position-dependent concentration gradient on the surface, which affects the geometry and chemistry of the final nanodeposit. Although simulations already proposed the local distribution of nozzle-borne gas molecules impinging on the surface, this isolated step in the FEBID process has never been experimentally measured yet. This work experimentally investigates the local distribution of impinging gas molecules on the sample plane, isolating the direct impingement component from surface diffusion or precursor depletion by deposition. The experimental setup used in this work maps and quantifies the local impinging rate of argon gas over the sample plane. This setup simulates the identical conditions for a precursor molecule during FEBID. Argon gas was locally collected with a sniffer tube, which is directly connected to a residual gas analyzer for quantification. The measured distribution of impinging gas molecules showed a strong position dependence. Indeed, a 300-µm shift of the deposition area to a position further away from the impingement center spot resulted in a 50 % decrease in the precursor impinging rate on the surface area. With the same parameters, the precursor distribution was also simulated by a Monte Carlo software by Friedli and Utke and showed a good correlation between the empirical and the simulated precursor distribution. The results hereby presented underline the importance of controlling the local precursor flux conditions in order to obtain reproducible and comparable deposition results in FEBID.

  18. The MR imaging features of the posterior intermalleolar ligament in patients with posterior impingement syndrome of the ankle

    International Nuclear Information System (INIS)

    Fiorella, D.

    1999-01-01

    Objective. To describe the MR imaging features of the posterior intermalleolar ligament (IML) in patients with posterior impingement syndrome (PIS) of the ankle.Design and patients. Three patients (one male and two females, 13-25 years of age) are presented. Each patient presented clinically with symptoms of PIS of the ankle. Plain film examination was negative for a structural cause of the PIS in all patients. MR images were obtained with a 1.5 T scanner using an extremity coil. Clinical data and, in one patient, findings at ankle arthroscopy, were correlated with the results of MR imaging.Results. Ankle MR images from the three patients with a clinical diagnosis of PIS are presented. Findings in all patients included: (1) absence of another structural cause of the PIS (i.e., an os trigonum, trigonal process, fracture, loose bodies, etc.), (2) identification of the IML as a structure discrete from the posterior talofibular and tibiofibular ligaments, and (3) prominence of the IML as indicated by (a) identification of the IML in three different imaging planes, and (b) a caliber of the IML comparable to that of the conventional posterior ankle ligaments visualized in the same imaging plane. Arthroscopic resection of a meniscoid IML resulted in resolution of the PIS in one of the patients presented.Conclusions. MR imaging is an effective means of investigating the IML as a potential cause of PIS. The identification of a prominent IML in the absence of another structural cause of PIS indicates that impingement of the IML is the most likely cause of PIS. (orig.)

  19. The MR imaging features of the posterior intermalleolar ligament in patients with posterior impingement syndrome of the ankle

    Energy Technology Data Exchange (ETDEWEB)

    Fiorella, D. [Duke Univ. Medical Center, Durham, NC (United States). Dept. of Radiology; Duke Univ., Durham, NC (United States). Medical Center; Helms, C.A. [Duke Univ. Medical Center, Durham, NC (United States). Dept. of Radiology; Nunley, J.A. II [Dept. of Orthopedic Surgery, Duke University Medical Center, Durham, NC (United States)

    1999-10-01

    Objective. To describe the MR imaging features of the posterior intermalleolar ligament (IML) in patients with posterior impingement syndrome (PIS) of the ankle.Design and patients. Three patients (one male and two females, 13-25 years of age) are presented. Each patient presented clinically with symptoms of PIS of the ankle. Plain film examination was negative for a structural cause of the PIS in all patients. MR images were obtained with a 1.5 T scanner using an extremity coil. Clinical data and, in one patient, findings at ankle arthroscopy, were correlated with the results of MR imaging.Results. Ankle MR images from the three patients with a clinical diagnosis of PIS are presented. Findings in all patients included: (1) absence of another structural cause of the PIS (i.e., an os trigonum, trigonal process, fracture, loose bodies, etc.), (2) identification of the IML as a structure discrete from the posterior talofibular and tibiofibular ligaments, and (3) prominence of the IML as indicated by (a) identification of the IML in three different imaging planes, and (b) a caliber of the IML comparable to that of the conventional posterior ankle ligaments visualized in the same imaging plane. Arthroscopic resection of a meniscoid IML resulted in resolution of the PIS in one of the patients presented.Conclusions. MR imaging is an effective means of investigating the IML as a potential cause of PIS. The identification of a prominent IML in the absence of another structural cause of PIS indicates that impingement of the IML is the most likely cause of PIS. (orig.)

  20. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT) Collector with Jet Impingement and Compound Parabolic Concentrator (CPC)

    OpenAIRE

    Ahed Hameed Jaaz; Husam Abdulrasool Hasan; Kamaruzzaman Sopian; Abdul Amir H. Kadhum; Tayser Sumer Gaaz; Ahmed A. Al-Amiery

    2017-01-01

    This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar ce...

  1. Numerical study of heat transfer enhancement due to the use of fractal-shaped design for impingement cooling

    Directory of Open Access Journals (Sweden)

    Cai Lin

    2017-01-01

    Full Text Available This paper describes a numerical analysis of a heat transfer enhancement technique that introduces fractal-shaped design for impingement cooling. Based on the gas turbine combustion chamber cooling, a fractal-shaped nozzle is designed for the constant flow area in a single impingement cooling model. The incompressible Reynolds-averaged Navier-Stokes equations are applied to the system using CFD software. The numerical results are compared with the experiment results for array impingement cooling.

  2. Lipoma arborescens: caso raro de ruptura do manguito rotador associado à presença de lipoma arborescens na bursa subacromial-subdeltoidea e glenoumeral Lipoma arborescens: rare case of rotator cuff tear associated with the presence of lipoma arborescens in the subacromial-subdeltoid and glenohumeral bursa

    Directory of Open Access Journals (Sweden)

    Eduardo Benegas

    2012-01-01

    Full Text Available Lipoma arborescens é uma condição rara de moléstia intra-articular, usualmente monoarticular, caracterizada por extensa proliferação dos vilos sinoviais e hiperplasia da gordura subsinovial. O tecido sinovial é progressivamente substituído por células maduras de gordura na membrana sinovial. O presente trabalho é o relato de caso de uma condição rara de lipoma arborescens tanto intra-articular (glenoumeral como da bursa subacromial-subdeltoide além de ruptura do tendão do supraespinhoso. As apresentações clínicas, histológicas e radiográficas assim como o tratamento são discutidos no presente estudo. A apresentação do caso contempla também a avaliação radiográfica, ressonância magnética e exame patológico. Apesar do lipoma arborescens ser uma condição rara, tal hipótese deve ser considerada frente a um caso com hiperproliferação sinovial e lipossubstituição da sinovial.Lipoma arborescens is a rare intra-articular disease that is usually monoarticular and is characterized by extensive proliferation of the synovial villi and hyperplasia of the subsynovial fat. The synovial tissue is progressively replaced by mature fat cells in the synovial membrane. The present study reports a case of a rare condition of lipoma arborescens that was simultaneously intra-articular (glenohumeral joint and in the subacromial-subdeltoid bursa, in association with a torn supraspinatus tendon. The clinical, histological and radiographic presentations and treatment are discussed here. The description of this case includes radiographic and magnetic resonance evaluations and pathological examination. Although lipoma arborescens is a rare condition, it should be taken into consideration in cases presenting synovial hyperproliferation and synovial fat replacement.

  3. Impingement of water droplets on wedges and diamond airfoils at supersonic speeds

    Science.gov (United States)

    Serafini, John S

    1953-01-01

    An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees to 460 degrees R. Also, free-stream Mach numbers from 1.1 to 2.0, semi-apex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.

  4. Hot air impingement on a flat plate using Large Eddy Simulation (LES) technique

    Science.gov (United States)

    Plengsa-ard, C.; Kaewbumrung, M.

    2018-01-01

    Impinging hot gas jets to a flat plate generate very high heat transfer coefficients in the impingement zone. The magnitude of heat transfer prediction near the stagnation point is important and accurate heat flux distribution are needed. This research studies on heat transfer and flow field resulting from a single hot air impinging wall. The simulation is carried out using computational fluid dynamics (CFD) commercial code FLUENT. Large Eddy Simulation (LES) approach with a subgrid-scale Smagorinsky-Lilly model is present. The classical Werner-Wengle wall model is used to compute the predicted results of velocity and temperature near walls. The Smagorinsky constant in the turbulence model is set to 0.1 and is kept constant throughout the investigation. The hot gas jet impingement on the flat plate with a constant surface temperature is chosen to validate the predicted heat flux results with experimental data. The jet Reynolds number is equal to 20,000 and a fixed jet-to-plate spacing of H/D = 2.0. Nusselt number on the impingement surface is calculated. As predicted by the wall model, the instantaneous computed Nusselt number agree fairly well with experimental data. The largest values of calculated Nusselt number are near the stagnation point and decrease monotonically in the wall jet region. Also, the contour plots of instantaneous values of wall heat flux on a flat plate are captured by LES simulation.

  5. Experimental and numerical investigation of liquid jet impingement on superhydrophobic and hydrophobic convex surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kibar, Ali, E-mail: alikibar@kocaeli.edu.tr [Department of Mechanical and Material Technologies, Kocaeli University, Arslanbey Campus, 41285, Kocaeli (Turkey)

    2017-02-15

    Experiments and numerical simulations were carried out to examine the vertical impingement a round liquid jet on the edges of horizontal convex surfaces that were either superhydrophobic or hydrophobic. The experiments examine the effects on the flow behaviour of curvature, wettability, inertia of the jet, and the impingement rate. Three copper pipes with outer diameters of 15, 22, and 35 mm were investigated. The pipes were wrapped with a piece of a Brassica oleracea leaf or a smooth Teflon sheet, which have apparent contact angles of 160° and 113°. The Reynolds number ranged from 1000 to 4500, and the impingement rates of the liquid jets were varied. Numerical results show good agreement with the experimental results for explaining flow and provide detailed information about the impingement on the surfaces. The liquid jet reflected off the superhydrophobic surfaces for all conditions. However, the jet reflected or deflected off the hydrophobic surface, depending on the inertia of the jet, the curvature of the surface, and the impingement rate. The results suggest that pressure is not the main reason for the bending of the jet around the curved hydrophobic surface. (paper)

  6. Investigation of vertical liquid film width upon impingement on flat plate

    International Nuclear Information System (INIS)

    Kim, Won J.; Son, Hyung M.; Suh, Kune Y.

    2003-01-01

    In the early, high pressure phase during a Large-Break Loss-Of-Coolant Accident (LBLOCA), the Emergency Core Cooling (ECC) water of the Direct Vessel Injection (DVI) system is supplied from the Safety Injection Tank (SIT). After the shortage of the SIT, the In-containment Refueling Water Storage Tank (IRWST) supplies water to the safety system. Velocity of the injection flow varies during the process from the initial value of over 10 m/s in the blowdown phase to 2∼3 m/s in the later phase of reflood. During the safety injection, such important phenomena are observed as impingement, bypass, entrainment and sweepout, and condensation. The impingement is referred to the case where the ECC water is injected to strike on the reactor inner vessel. Accordingly, the water generates a liquid film to form a ridge on the wall. The liquid film then flows down the wall due to gravity. This impingement is interrupted by the steam-water mixture bypass flow to the break. The bypass, in turn, is affected by the impingement. This study is intended to understand the impinged water flow behavior neglecting such secondary effects as the temperature-dependent thermodynamic properties and the reactor vessel curvature. An emphasis is put on interpreting the results of visual inspection to understand the underlying mechanism of rather complex turbulent flow in the downcomer

  7. Experimental and numerical investigation of liquid jet impingement on superhydrophobic and hydrophobic convex surfaces

    International Nuclear Information System (INIS)

    Kibar, Ali

    2017-01-01

    Experiments and numerical simulations were carried out to examine the vertical impingement a round liquid jet on the edges of horizontal convex surfaces that were either superhydrophobic or hydrophobic. The experiments examine the effects on the flow behaviour of curvature, wettability, inertia of the jet, and the impingement rate. Three copper pipes with outer diameters of 15, 22, and 35 mm were investigated. The pipes were wrapped with a piece of a Brassica oleracea leaf or a smooth Teflon sheet, which have apparent contact angles of 160° and 113°. The Reynolds number ranged from 1000 to 4500, and the impingement rates of the liquid jets were varied. Numerical results show good agreement with the experimental results for explaining flow and provide detailed information about the impingement on the surfaces. The liquid jet reflected off the superhydrophobic surfaces for all conditions. However, the jet reflected or deflected off the hydrophobic surface, depending on the inertia of the jet, the curvature of the surface, and the impingement rate. The results suggest that pressure is not the main reason for the bending of the jet around the curved hydrophobic surface. (paper)

  8. Experimental observations and modelling of thermal history within a steel plate during water jet impingement

    International Nuclear Information System (INIS)

    Liu, Z.D.; Fraser, D.; Samarasekera, I.V.; Lockhart, G.T.

    2002-01-01

    In order to investigate heat transfer of steel plates under a water jet impingement and to further simulate runout table operation in a hot strip mill, a full-scale pilot runout table facility was designed and constructed at the University of British Columbia (UBC). This paper describes the experimental details, data acquisition and data handling techniques for steel plates during water jet impingement by one circular water jet from an industrial header. Recorded visual observations at the impinging surface were obtained. The effects of cooling water temperature and impingement velocity on the heat transfer from a steel plate were studied. A two-dimensional finite element method-based transient inverse heat conduction model was developed. With the help of the model, heat fluxes and heat transfer coefficients along the impinging surface under various cooling conditions were calculated. The microstructural evolution of the steel plate was also investigated for the varying cooling conditions. Samples were obtained from each plate, polished, etched and then photographed. (author)

  9. Impact of impingement on the Hudson River white perch population. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Barnthouse, L.W.; Van Winkle, W.; Kirk, B.L.; Vaughan, D.S.

    1982-02-01

    This report summarizes a series of analyses of the magnitude and biological significance of the impingement of white perch at the Indian Point Nuclear Generating Station and other Hudson River power plants. Included in these analyses were evaluations of: (1) two independent lines of evidence relating to the magnitude of impingement impacts on the Hudson River white perch population; (2) the additional impact caused by entrainment of white perch; (3) data relating to density-dependent growth among young-of-the-year white perch; (4) the feasibility of performing population-level analyses of impingement impacts on the white perch populations of Chesapeake Bay and the Delaware River; and (5) the feasibility of using simple food chain and food web models to evaluate community-level effects of impingement and entrainment. Estimated reductions in the abundances of the 1974 and 1975 white perch year classes, caused by impingement and entrainment, were high enough that the possibility of adverse long-term effects cannot be excluded.

  10. Prevalence of calcific deposits within the rotator cuff tendons in adults with and without subacromial pain syndrome: clinical and radiologic analysis of 1219 patients.

    Science.gov (United States)

    Louwerens, Jan K G; Sierevelt, Inger N; van Hove, Ruud P; van den Bekerom, Michel P J; van Noort, Arthur

    2015-10-01

    Calcific tendinopathy is one of the most frequent causes of pain in the shoulder and is characterized by the presence of calcific deposits in the rotator cuff; however, calcific deposits have also been described in asymptomatic individuals. Only a few authors have reported epidemiologic data on the prevalence of calcific deposits in the rotator cuff. This study analyzed clinical and radiological data of 1219 adults with and without subacromial pain syndrome (SAPS) to assess the prevalence of calcific deposits in the rotator cuff. Multivariate analysis was used to define risk factors associated with the presence of symptomatic calcific tendinopathy. Calcific deposits were found in the rotator cuff of 57 of 734 asymptomatic patients (7.8%). Of 485 patients with SAPS, 42.5% had calcific deposits. Age between 30 and 60 years (odds ratio [OR], 8.0; 95% confidence interval [CI], 2.5-26.3; P pain (OR, 7.1; 95% CI, 5.1-9.9, P 1.5 cm in length have the highest chance of suffering from symptomatic calcific tendinopathy of the rotator cuff. The prevalence rates of 7.8% in asymptomatic patients and 42.5% in patients with SAPS provide a current view on the epidemiology of calcific deposits in the rotator cuff. Copyright © 2015 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  11. Effect of a novel mobilization with movement procedure on anterolateral ankle impingement - A case report.

    Science.gov (United States)

    Anandkumar, Sudarshan

    2018-07-01

    This case report describes a 50-year-old male who presented with right anterolateral ankle pain managed unsuccessfully with rest, medications, bracing, injection, physical therapy, and massage therapy. Clinical diagnosis of anterolateral ankle impingement was based on concordant symptom reproduction with palpatory tenderness and a positive lateral synovial impingement test. This case report is a potential first time description of the successful management of anterolateral ankle impingement utilizing a novel Mulligan's mobilization with movement procedure (consisting of internal rotation of the distal tibia) and taping with immediate improvements noted in pain, range of motion, and function. The patient was seen twice a week and was discharged after four treatment sessions. A follow-up after 4 months revealed that the patient was pain free and fully functional.

  12. Numerical analysis of droplet impingement using the moving particle semi-implicit method

    International Nuclear Information System (INIS)

    Xiong, Jinbiao; Koshizuka, Seiichi; Sakai, Mikio

    2010-01-01

    Droplet impingement onto a rigid wall is simulated in two and three dimensions using the moving particle semi-implicit method. In two-dimensional calculations, the convergence is achieved and the propagation of a shockwave in a droplet is captured. The average pressure on the contact area decreases gradually after the maximum value. The numerically obtained maximum average impact pressure agrees with the Heymann correlation. A large shear stress appears at the contact edge due to jetting. A parametric study shows that the droplet diameter has only a minor effect on the pressure load due to droplet impingement. When the impingement takes place from an impact angle of π/4 rad, the pressure load and shear stress show a dependence only on the normal velocity to the wall. A comparison between the three-dimensional and two-dimensional results shows that consideration of the three-dimensional effect can decrease the average impact pressure by about 12%. (author)

  13. "Simultaneous measurement of flame impingement and piston surface temperatures in an optically accessible spark ignition engine"

    Science.gov (United States)

    Ding, Carl-Philipp; Honza, Rene; Böhm, Benjamin; Dreizler, Andreas

    2017-04-01

    This paper shows the results of spatially resolved temperature measurements of the piston surface of an optically accessible direct injection spark ignition engine during flame impingement. High-speed thermographic phosphor thermometry (TPT), using Gd3Ga5O12:Cr,Ce, and planar laser-induced fluorescence of the hydroxyl radical (OH-PLIF) were used to investigate the temperature increase and the time and position of flame impingement at the piston surface. Measurements were conducted at two operating cases and showed heating rates of up to 16,000 K/s. The OH-PLIF measurements were used to localize flame impingement and calculate conditioned statistics of the temperature profiles. The TPT coating was characterized and its influence on the temperature measurements evaluated.

  14. Effect of wall impingement on ambient gas entrainment, fuel evaporation and mixture formation of diesel spray

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Keiya [Department of Mechanical Physics Engineering, University of Hiroshima (Japan); Matsumoto, Yuhei; Zhang, Wu [Mazda Motor Corp. (Japan); Gao, Jian [University of Wisconsin (United States); Moon, Seoksu [Argonne National Laboratory (United States)

    2010-07-01

    In the energy sector, with the implementation of stringent regulations on combustion emissions and the depletion of conventional fuels, there is a pressing need to improve the performance of engines. The purpose of this paper is to determine the impact of wall impingement on several characteristics of diesel spray. Experiments were carried out with both a small and a large amount of diesel spray injected and ambient gas entrainment, fuel evaporation and mixture formation were evaluated using an LAS optical system. Results showed that wall impingement has the same effects for small or large amounts of diesel spray injected; these are: a larger volume spray after the impingement and a smaller volume after it, the suppression of ambient gas entrainment and fuel evaporation, and the shift of the PDF peak of the vapor equivalent ratio. This study provided useful information but further work is needed to address the remaining issues.

  15. Numerical modeling of normal turbulent plane jet impingement on solid wall

    Energy Technology Data Exchange (ETDEWEB)

    Guo, C.Y.; Maxwell, W.H.C.

    1984-10-01

    Attention is given to a numerical turbulence model for the impingement of a well developed normal plane jet on a solid wall, by means of which it is possible to express different jet impingement geometries in terms of different boundary conditions. Examples of these jets include those issuing from VTOL aircraft, chemical combustors, etc. The two-equation, turbulent kinetic energy-turbulent dissipation rate model is combined with the continuity equation and the transport equation of vorticity, using an iterative finite difference technique in the computations. Peak levels of turbulent kinetic energy occur not only in the impingement zone, but also in the intermingling zone between the edges of the free jet and the wall jet. 20 references.

  16. Rotation Effect on Jet Impingement Heat Transfer in Smooth Rectangular Channels with Film Coolant Extraction

    Directory of Open Access Journals (Sweden)

    James A. Parsons

    2001-01-01

    Full Text Available The effect of channel rotation on jet impingement cooling by arrays of circular jets in twin channels was studied. Impinging jet flows were in the direction of rotation in one channel and opposite to the direction of rotation in the other channel. The jets impinged normally on the smooth, heated target wall in each channel. The spent air exited the channels through extraction holes in each target wall, which eliminates cross flow on other jets. Jet rotation numbers and jet Reynolds numbers varied from 0.0 to 0.0028 and 5000 to 10,000, respectively. For the target walls with jet flow in the direction of rotation (or opposite to the direction of rotation, as rotation number increases heat transfer decreases up to 25% (or 15% as compared to corresponding results for non-rotating conditions. This is due to the changes in flow distribution and rotation induced Coriolis and centrifugal forces.

  17. Trunk and lower limb biomechanics during stair climbing in people with and without symptomatic femoroacetabular impingement.

    Science.gov (United States)

    Hammond, Connor A; Hatfield, Gillian L; Gilbart, Michael K; Garland, S Jayne; Hunt, Michael A

    2017-02-01

    Femoroacetabular impingement is a pathomechanical hip condition leading to pain and impaired physical function. It has been shown that those with femoroacetabular impingement exhibit altered gait characteristics during level walking and stair climbing, and decreased muscle force production during isometric muscle contractions. However, no studies to-date have looked at trunk kinematics or muscle activation during dynamic movements such as stair climbing in this patient population. The purpose of this study was to compare biomechanical outcomes (trunk and lower limb kinematics as well as lower limb kinetics and muscle activation) during stair climbing in those with and without symptomatic femoroacetabular impingement. Trunk, hip, knee and ankle kinematics, as well as hip, knee and ankle kinetics and muscle activity of nine lower limb muscles were collected during stair climbing for 20 people with clinical and radiographic femoroacetabular impingement and compared to 20 age- and sex-matched pain-free individuals. Those with femoroacetabular impingement ascended the stairs slower (effect size=0.82), had significantly increased peak trunk forward flexion angles (effect size=0.99) and external hip flexion moments (effect size=0.94) and had decreased peak external knee flexion moments (effect size=0.90) compared to the control group. Findings from this study indicate that while those with and without femoroacetabular impingement exhibit many biomechanical similarities when ascending stairs, differences in trunk forward flexion and joint kinetics indicate some important differences. Further longitudinal research is required to elucidate the cause of these differences as well as the clinical relevance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Practicality of profile-wire screen in reducing entrainment and impingement

    International Nuclear Information System (INIS)

    Hanson, B.N.; Bason, W.H.; Beitz, B.E.; Charles, K.E.

    1978-01-01

    Experimental studies indicated that 1.01-mm slot profile-wire well screen operated at an intake velocity of 15.24 cm/s virtually eliminated impingement of fishes larger than 15 mm fork length (FL). Intake velocities as high as 53.34 cm/s produced low impingement. Tests of fish less than 40 mm FL held near a functioning intake (15.24 cm/s) for as long as 3 hr yielded no impingement or stress. Many striped bass between 8 and 17 mm FL were capable of resisting impingement at more than 30.48 cm/s velocity for longer than 30 min; larger specimens (12 to 17 mm) showed excellent ability to escape when impinged. The screen excluded virtually all striped bass eggs from the cooling water. Preliminary egg mortality studies indicate that at least 95% survival can be expected at an approach velocity of 15.24 cm/s and impingement durations up to 2 min. Fouling studies showed that screens were highly resistant to clogging, essentially self-cleaning in a current, and easily backwashed. In-situ studies in the Chesapeake and Delaware Canal have shown that a 61.0- x 76.2-cm, 1.01-mm-slot screen is capable of providing its designed capacity for weeks without backwashing or cleaning. Biofouling proved to be the greatest operational problem. Entrainment samples from the in-situ intake have shown significant reductions in organisms/m 3 of filtered versus ambient water

  19. Exploration of Impinging Water Spray Heat Transfer at System Pressures Near the Triple Point

    Science.gov (United States)

    Golliher, Eric L.; Yao, Shi-Chune

    2013-01-01

    The heat transfer of a water spray impinging upon a surface in a very low pressure environment is of interest to cooling of space vehicles during launch and re-entry, and to industrial processes where flash evaporation occurs. At very low pressure, the process occurs near the triple point of water, and there exists a transient multiphase transport problem of ice, water and water vapor. At the impingement location, there are three heat transfer mechanisms: evaporation, freezing and sublimation. A preliminary heat transfer model was developed to explore the interaction of these mechanisms at the surface and within the spray.

  20. FLOW VISUALIZATION OF RECTANGULAR SLOT AIR JET IMPINGEMENT ON FLAT SURFACES

    OpenAIRE

    Satheesha V *1, B. K. Muralidhra2, Abhilash N3, C. K. Umesh4

    2018-01-01

    Jet impingement near the mid-chord of the gas turbine blade is treated as a flat plate. Experimental and numerical investigations are carried out for a single slot air jet impinging on flat surface for two different rectangular slots of dimension (3mm x 65 mm) and (5mm x 65 mm). Experimentation is done to study the flow pattern topography on the flat target plate, with varying the flow rate from 20 LPM to 50 LPM by varying the nozzle to plate distance from 9 mm to 24 mm for slot jet of 3mm an...

  1. Imaging evaluation of the hip after arthroscopic surgery for femoroacetabular impingement

    International Nuclear Information System (INIS)

    Crim, Julia

    2017-01-01

    Arthroscopic surgery for femoroacetabular impingement (FAI) is increasingly frequently performed. Initial reports were that complications were very low, but as experience has increased, a number of long-term complications, in addition to factors related to poor clinical outcomes, have been identified. This review describes the normal and abnormal postoperative imaging appearance of the hip after arthroscopy for FAI. Abnormalities discussed include incomplete resection or over-resection of the impingement lesion, heterotopic ossification, cartilage damage, chondrolysis, instability and dislocation, recurrent labral tear, adhesions, psoas atrophy, infection, and avascular necrosis. (orig.)

  2. Characteristics of compressed natural gas jet and jet-wall impingement using the Schlieren imaging technique

    International Nuclear Information System (INIS)

    Ismael, M A; Heikal, M R; Baharom, M B

    2013-01-01

    An experimental study was performed to investigate the compressed natural gas jet characteristics and jet-wall impingement using the Schlieren imaging technique and image processing. An injector driver was used to drive the natural gas injector and synchronized with camera triggering. A constant-volume optical chamber was designed to facilitate maximum optical access for the study of the jet macroscopic characteristics and jet-wall impingement at different injection pressures and injectors-wall distances. Measurement of the jet tip penetration and cone angle at different conditions are presented in this paper together with temporal presentation of the jet radial travel along the wall.

  3. Impingement syndrome and rotator cuff tears: US findings in 140 patients

    International Nuclear Information System (INIS)

    Malvestiti, Oreste; Scorsolini, Alessandro; Ratti, Francesco; Ferraris, Giuseppe; Columbaro, Guido; Mariani, Claudio

    1997-01-01

    The authors investigated the role of rotator cuff impingement in causing tears of supraspinatus and biceps tendons and the comparative reliability of plain radiography and sonography (US). One hundred forty patients with symtoms referrable to the rotator cuff were examined with plain radiography and US of the shoulder. The differential diagnosis must distinguish all these common causes of shoulder dysfunction and cuff problems from other conditions. The authors conclude that US and plain radiography are accurate routine tests of rotator cuff integrity and rotator cuff impingement

  4. Glyceryl trinitrate patches—An alternative treatment for shoulder impingement syndrome

    Directory of Open Access Journals (Sweden)

    Yusuf Assem

    2015-01-01

    Full Text Available Transdermal glyceryl trinitrate patches have been investigated as an alternative therapeutic intervention for a range of tendinopathies, due to the ease of titration of dosage and the ease of their application. Glyceryl trinitrate has been inferred to reduce pain and inflammation secondary to their nitric oxide-producing action. Shoulder impingement syndrome is a soft tissue condition that manifests as anterior shoulder pain, weakness, and difficulty in daily activities. This review will evaluate the efficacy of glyceryl trinitrate patches in treating a variety of rotator cuff tendinopathies related to shoulder impingement, based on human and animal trials, and suggest its practical application in future trials and management.

  5. Imaging evaluation of the hip after arthroscopic surgery for femoroacetabular impingement

    Energy Technology Data Exchange (ETDEWEB)

    Crim, Julia [University of Missouri at Columbia, Columbia, MO (United States)

    2017-10-15

    Arthroscopic surgery for femoroacetabular impingement (FAI) is increasingly frequently performed. Initial reports were that complications were very low, but as experience has increased, a number of long-term complications, in addition to factors related to poor clinical outcomes, have been identified. This review describes the normal and abnormal postoperative imaging appearance of the hip after arthroscopy for FAI. Abnormalities discussed include incomplete resection or over-resection of the impingement lesion, heterotopic ossification, cartilage damage, chondrolysis, instability and dislocation, recurrent labral tear, adhesions, psoas atrophy, infection, and avascular necrosis. (orig.)

  6. The role of femoroacetabular impingement in core muscle injury/athletic pubalgia: diagnosis and management

    Directory of Open Access Journals (Sweden)

    Thomas eEllis

    2016-02-01

    Full Text Available Chronic groin pain in athletes represents a major diagnostic and therapeutic challenge in sports medicine. Two recognized causes of inguinal pain in the young adult athlete are core muscle injury/athletic pubalgia (CMI/AP and femoroacetabular impingement (FAI. CMI/AP and FAI were previously considered to be two distinct entities, however recent studies have suggested both entities to frequently coincide in the athlete with groin pain. This article briefly discusses the role of femoroacetabular impingement in core muscle injury/athletic pubalgia, and the diagnosis and management of this complex disease.

  7. Cam Femoroacetabular Impingement as a Possible Explanation of Recalcitrant Anterior Knee Pain

    OpenAIRE

    Sanchis-Alfonso, Vicente; Tey, Marc; Monllau, Joan Carles

    2016-01-01

    We present a case of a patient with chronic anterior knee pain (AKP) recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI) at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patie...

  8. Time resolved investigations on flow field and quasi wall shear stress of an impingement configuration with pulsating jets by means of high speed PIV and a surface hot wire array

    International Nuclear Information System (INIS)

    Janetzke, Timm; Nitsche, Wolfgang

    2009-01-01

    The effects of jet pulsation on flow field and quasi wall shear stress of an impingement configuration were investigated experimentally. The excitation Strouhal number and amplitude were varied as the most influential parameters. A line-array with three submerged air jets, and a confining plate were used. The flow field analysis by means of time resolved particle image velocimetry shows that the controlled excitation can considerably affect the near-field flow of an impinging jet array. These effects are visualized as organization of the coherent flow structures. Augmentation of the Kelvin-Helmholtz vortices in the jet shear layer depends on the Strouhal number and pulsation magnitude and can be associated with pairing of small scale vortices in the jet. A total maximum of vortex strength was observed when exciting with Sr = 0.82 and coincident high amplitudes. Time resolved interaction between impinging vortices and impingement plate boundary layer due to jet excitation was verified by using an array of 5 μm surface hot wires. Corresponding to the global flow field modification due to periodic jet pulsation, the impact of the vortex rings on the wall boundary layer is highly influenced by the above mentioned excitation parameters and reaches a maximum at Sr = 0.82.

  9. Clinical application of arthroscopy in the diagnosis and treatment of anterior impingement syndrome of the ankle joint in physical workers.

    Science.gov (United States)

    Wu, Wen-Te; Chen, Zhi-Wei; Zhou, Yu-Cheng

    2012-10-01

    To evaluate the clinical application of arthroscopy in the diagnosis and treatment of anterior impingement syndrome of the ankle joint in physical workers. A retrospective study was carried out at the Department of Orthopedics, the First Hospital affiliated to Nanhua University, Hengyang, China from March 2005 to December 2011. Seventeen cases of anterior impingement syndrome of the ankle joint were confirmed, and treated through arthroscopy. All these patients conformed to regular follow-up postoperatively, and clinical details, as well as postoperative prognosis were retrieved and analyzed retrospectively. The efficacy was evaluated by the American Orthopedic Foot and Ankle Society (AOFAS) hindfoot-ankle scoring system, and pain relief was assessed by visual analogue scoring (VAS). Anterolateral impingement syndrome was found in 11 patients, anteromedial impingement syndrome in 4, while anterior impingement syndrome in 2 via arthroscopic examination. The VAS was reduced from 5.2-1.1, and the AOFAS score was elevated from 76.4-95.8 postoperatively; both of which demonstrated statistical differences when compared to preoperative scores. It was also found that concomitant cartilage damage was an indicator of poor prognosis in arthroscopic treatment of impingement syndrome of the ankle joint. Satisfactory results could be achieved for physical workers with anterior impingement syndrome treated by arthroscopy. As the cartilage damage is an indicator of poor prognosis, an early operation is advocated when the prognosis of anterior impingement syndrome is confirmed.

  10. Trunk, pelvis and hip biomechanics in individuals with femoroacetabular impingement syndrome: Strategies for step ascent.

    Science.gov (United States)

    Diamond, Laura E; Bennell, Kim L; Wrigley, Tim V; Hinman, Rana S; Hall, Michelle; O'Donnell, John; Hodges, Paul W

    2018-03-01

    Femoroacetabular impingment (FAI) syndrome is common among young active adults and a proposed risk factor for the future development of hip osteoarthritis. Pain is dominant and drives clinical decision-making. Evidence for altered hip joint function in this patient population is inconsistent, making the identification of treatment targets challenging. A broader assessment, considering adjacent body segments (i.e. pelvis, trunk) and individual movement strategies, may better inform treatment programs. This exploratory study aimed to compare trunk, pelvis, and hip biomechanics during step ascent between individuals with and without FAI syndrome. Fifteen participants diagnosed with symptomatic cam-type or combined (cam plus pincer) FAI who were scheduled for arthroscopic surgery, and 11 age-, and sex-comparable pain- and disease-free individuals, underwent three-dimensional motion analysis during a step ascent task. Trunk, pelvis and hip biomechanics were compared between groups. Participants with FAI syndrome exhibited altered ipsilateral trunk lean and pelvic rise towards the symptomatic side during single-leg support compared to controls. Alterations were not uniformly adopted across all individuals with FAI syndrome; those who exhibited more pronounced alterations to frontal plane pelvis control tended to report pain during the task. There were minimal between-group differences for hip biomechanics. Exploratory data suggest biomechanics at the trunk and pelvis during step ascent differ between individuals with and without FAI syndrome. Those with FAI syndrome implement a range of proximal strategies for task completion, some of which may have relevance for rehabilitation. Longitudinal investigations of larger cohorts are required to evaluate hypothesized clinical and structural consequences. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. On angled bounce-off impact of a drop impinging on a flowing soap film

    Science.gov (United States)

    Basu, Saikat; Yawar, Ali; Concha, Andres; Bandi, M. M.

    2017-12-01

    Small drops impinging obliquely on thin flowing soap films frequently demonstrate the rare emergence of bulk elastic effects working in-tandem with the more commonplace hydrodynamic interactions. Three collision regimes are observable: (a) drop piercing through the film, (b) it coalescing with the flow, and (c) it bouncing off the film surface. During impact, the drop deforms along with a bulk elastic deformation of the film. For impacts that are close-to-tangential, the bounce-off regime predominates. We outline a reduced order analytical framework assuming a deformable drop and a deformable three-dimensional film, and the idealization invokes a phase-based parametric study. Angular inclination of the film and the ratio of post and pre-impact drop sizes entail the phase parameters. We also perform experiments with vertically descending droplets (constituted from deionized water) impacting against an inclined soap film, flowing under constant pressure head. Model-predicted phase domain for bounce-off compares well to our experimental findings. Additionally, the experiments exhibit momentum transfer to the film in the form of shed vortex dipoles, along with propagation of free surface waves. On consulting prior published work, we note that for locomotion of water-walking insects using an impulsive action, the momentum distribution to the shed vortices and waves are both significant, taking up respectively 2/3 and 1/3 of the imparted streamwise momentum. Considering the visually similar impulse actions, this theory, despite its assumption of a quiescent liquid bath of infinite depth, is applied to the drop bounce-off experiments, and the resultant shed vortex dipole momenta are compared to the momenta of the coherent vortex structures computed from particle imaging velocimetry data. The magnitudes reveal identical order (10-7 N s), suggesting that notwithstanding the disparities, the bounce-off regime may be tapped as a toy analog for impulse-based interfacial

  12. Zonal migration and transport variations of the Kuroshio east of Taiwan induced by eddy impingements

    Science.gov (United States)

    Chang, Ming-Huei; Jan, Sen; Mensah, Vigan; Andres, Magdalena; Rainville, Luc; Yang, Yiing Jang; Cheng, Yu-Hsin

    2018-01-01

    Variability of the Kuroshio east of Taiwan was observed at a cross-stream transect 50 km south of the PCM-1 line with an array of three moored ADCPs measuring for 23 months, supplemented with eleven repeated shipboard surveys. Observations of the Kuroshio's velocity structure reveal the absence of an obvious regular seasonal signal, but significant variability at 70-200 day period for both maximum velocity axis migration and transport due to interactions with mesoscale eddies. Empirical orthogonal function (EOF) analysis shows the migration and transport modes explain 46% and 29% of the total variance, respectively, which is in contrast to the findings at the PCM-1 line where the transport mode explained more variance than did the migration mode. The Kuroshio transport in the upper 500 m across a 150 km section is 17.2 Sv with a standard deviation of 5 Sv. The estimated Kuroshio transport is 4.3 Sv lower than that reported for the PCM-1 line, likely due to the interannual variations related to abundance of mesoscale eddies in the Subtropical Counter Current (STCC) region. Transport variability east of Taiwan is mostly caused by Kuroshio-eddy interactions. When single anticyclonic (cyclonic) eddies encounter the Kuroshio, they enhance (reduce) poleward transport, presumably by increasing (decreasing) the sea level anomaly (SLA) along the eastern flank of the Kuroshio (correlation = 0.82). When a pair of eddies impinges on the Kuroshio, the upstream confluence and diffluence caused by the dipole eddies increases and decreases the Kuroshio transport, respectively. Furthermore, the eastward (westward) currents that result from either the single eddy or the dipole eddy produce flow divergence (convergence) adjacent to the Kuroshio's eastern edge, favoring the offshore (onshore) migration of the Kuroshio axis.

  13. Detection of airborne Legionella while showering using liquid impingement and fluorescent in situ hybridization (FISH).

    Science.gov (United States)

    Deloge-Abarkan, Magali; Ha, Thi-Lan; Robine, Enric; Zmirou-Navier, Denis; Mathieu, Laurence

    2007-01-01

    Aerosols of water contaminated with Legionella bacteria constitute the only mode of exposure for humans. However, the prevention strategy against this pathogenic bacteria risk is managed through the survey of water contamination. No relationship linked the Legionella bacteria water concentration and their airborne abundance. Therefore, new approaches in the field of the metrological aspects of Legionella bioaerosols are required. This study was aimed at testing the main principles for bioaerosol collection (solid impaction, liquid impingement and filtration) and the in situ hybridization (FISH) method, both in laboratory and field assays, with the intention of applying such methodologies for airborne Legionella bacteria detection while showering. An aerosolization chamber was developed to generate controlled and reproducible L. pneumophila aerosols. This tool allowed the identification of the liquid impingement method as the most appropriate one for collecting airborne Legionella bacteria. The culturable fraction of airborne L. pneumophila recovered with the liquid impingement principle was 4 and 700 times higher compared to the impaction and filtration techniques, respectively. Moreover, the concentrations of airborne L. pneumophila in the impinger fluid were on average 7.0 x 10(5) FISH-cells m(-3) air with the fluorescent in situ hybridization (FISH) method versus 9.0 x 10(4) CFU m(-3) air with the culture method. These results, recorded under well-controlled conditions, were confirmed during the field experiments performed on aerosols generated by hot water showers in health institutions. This new approach may provide a more accurate characterization of aerobiocontamination by Legionella bacteria.

  14. Impinging jet study of the deposition of colloidal particles on synthetic polymer (Zeonor)

    DEFF Research Database (Denmark)

    Vlček, Jakub; Lapčík, Lubomír; Cech, Jiri

    2014-01-01

    In this study, an impinging jet deposition experiments were performed on synthetic polymer (Zeonor) original and by micro-embossing modified substrates with exactly defined topology as confirmed by AFM and SEM. Deposition experiments were performed at ambient temperature and at selected flow regi...

  15. Is there any value to arthroscopic debridement of ankle osteoarthritis and impingement?

    Science.gov (United States)

    Phisitkul, Phinit; Tennant, Joshua N; Amendola, Annunziato

    2013-09-01

    This article summarizes the current literature regarding the use of arthroscopy for the various types of ankle osteoarthritis with impingement symptoms. Discussion includes the role of diagnostic arthroscopy and adjunctive use of arthroscopy with other modalities. The section on the authors' preferred technique describes our current operative and perioperative strategies in detail. Published by Elsevier Inc.

  16. Impingement heat/mass transfer to hybrid synthetic jets and other reversible pulsating jets

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Vít, T.

    2015-01-01

    Roč. 85, June (2015), s. 473-487 ISSN 0017-9310 R&D Projects: GA ČR GA14-08888S Institutional support: RVO:61388998 Keywords : impinging jet * reversible pulsating jet * synthetic jet Subject RIV: JU - Aeronautics, Aerodynamics, Aircrafts Impact factor: 2.857, year: 2015 http://www.sciencedirect.com/science/article/pii/S001793101500143X

  17. Modeling of soft impingement effect during solid-state partitioning phase transformations in binary alloys

    NARCIS (Netherlands)

    Chen, H.; Van der Zwaag, S.

    2010-01-01

    The soft impingement effect at the later stage of partitioning phase transformations has been modeled both for the diffusion-controlled growth model and for the mixed-mode model. Instead of the linear and exponential approximations for the concentration gradient in front of the interface used in the

  18. Etiology of the anterior ankle impingement syndrome: A descriptive anatomical study

    NARCIS (Netherlands)

    Tol, Johannes L.; van Dijk, C. Niek

    2004-01-01

    Background: In the anterior ankle impingement syndrome, recurrent traction to the anterior joint capsule is stated to be the cause of formation of talotibial osteophytes. This hypothesis involves the assumption that the osteophytes originate at the site where a capsular attachment is located. A soft

  19. Role of the confinement of a root canal on jet impingement during endodontic irrigation

    NARCIS (Netherlands)

    Verhaagen, B.; Boutsioukis, C.; Heijnen, G. L.; van der Sluis, L. W. M.; Versluis, M.

    2012-01-01

    During a root canal treatment the root canal is irrigated with an antimicrobial fluid, commonly performed with a needle and a syringe. Irrigation of a root canal with two different types of needles can be modeled as an impinging axisymmetric or non-axisymmetric jet. These jets are investigated

  20. Atmospheric H2O2 measurement: comparison of cold trap method with impinger bubbling method

    Science.gov (United States)

    Sakugawa, H.; Kaplan, I. R.

    1987-01-01

    Collection of atmospheric H2O2 was performed by a cold trap method using dry ice-acetone as the refrigerant. The air was drawn by a pump into a glass gas trap immersed in the dry ice-acetone slush in a dewar flask at a flow rate of 2.5 l min-1 for approximately 2 h. Collection efficiency was > 99% and negligible interferences by O3, SO2 or organic matter with the collected H2O2 in the trap were observed. This method was compared with the air impinger bubbling method which has been previously described (Kok et al., 1978a, b, Envir. Sci. Technol. 12, 1072-1080). The measured total peroxide (H2O2 + organic peroxide) values in a series of aim samples collected by the impinger bubbling method (0.06-3.7 ppb) were always higher than those obtained by the cold trap method (0.02-1.2 ppb). Laboratory experiments suggest that the difference in values between the two methods probably results from the aqueous phase generation of H2O2 and organic peroxide in the impinger solution by a reaction of atmospheric O3 with olefinic and aromatic compounds. If these O3-organic compound reactions which occur in the impinger also occur in aqueous droplets in the atmosphere, the process could be very important for aqueous phase generation of H2O2 in clouds and rainwater.

  1. Anterolateral ankle impingement in adolescents: outcomes of nonoperative and operative treatment.

    Science.gov (United States)

    Edmonds, Eric W; Chambers, Reid; Kaufman, Elizabeth; Chambers, Henry G

    2010-03-01

    Ankle sprains in adolescents usually resolve with conservative management but a few patients may develop ankle impingement syndrome. There have been adult studies addressing surgical treatment of this pathology, but our study evaluated the surgical management of anterolateral ankle impingement in adolescents by comparing their outcomes after nonoperative treatment and subsequent surgical intervention. Thirteen patients (children and adolescents) diagnosed with ankle impingement by history, physical examination, and magnetic resonance imaging during a 9-year period at our institution underwent eventual arthroscopic debridement. A retrospective chart review of these patients was performed and they were evaluated using the American Orthopedic Foot and Ankle Society (AOFAS) functional rating scale on 3 separate occasions: (1) initial presentation, (2) termination of nonoperative management, and (3) final postoperative follow-up visit. Thirteen adolescents (11 girls and 2 boys; 14 ankles) with a mean age of 15.6 (11.9-18.3) years met the inclusion criteria; of these, all had arthroscopic surgery. Mean duration of reported symptoms was 9.6 (4-15) months and mean duration of nonoperative management (physical therapy, activity modifications) was 6.9 (2-12) months. The mean AOFAS rating (out of 100 total) at initial presentation was 68.4 (40-84) and after nonoperative management was no better with a mean of 68.2 (63-76). The mean AOFAS rating at final follow-up was 90.6 (52-100), which was statistically significant (Pankle impingement in the adolescent population.

  2. Visualization and mass transfer with a bistable two-slot impinging jet

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Maršík, František

    2003-01-01

    Roč. 6, č. 4 (2003), s. 337-441 ISSN 1343-8875 R&D Projects: GA AV ČR IAA2076203 Institutional research plan: CEZ:AV0Z2076919 Keywords : visualization * mass transfer * impinging jet Subject RIV: BK - Fluid Dynamics Impact factor: 0.279, year: 2002

  3. Computational Analysis of Droplet Mass and Size Effect on Mist/Air Impingement Cooling Performance

    Directory of Open Access Journals (Sweden)

    Zhenglei Yu

    2013-01-01

    Full Text Available Impingement cooling has been widely employed to cool gas turbine hot components such as combustor liners, combustor transition pieces, turbine vanes, and blades. A promising technology is proposed to enhance impingement cooling with water droplets injection. However, previous studies were conducted on blade shower head film cooling, and less attention was given to the transition piece cooling. As a continuous effort to develop a realistic mist impingement cooling scheme, this paper focuses on simulating mist impingement cooling under typical gas turbine operating conditions of high temperature and pressure in a double chamber model. Furthermore, the paper presents the effect of cooling effectiveness by changing the mass and size of the droplets. Based on the heat-mass transfer analogy, the results of these experiments prove that the mass of 3E – 3 kg/s droplets with diameters of 5–35 μm could enhance 90% cooling effectiveness and reduce 122 K of wall temperature. The results of this paper can provide guidance for corresponding experiments and serve as the qualification reference for future more complicated studies with convex surface cooling.

  4. Computations of droplet impingement on airfoils in two-phase flow

    International Nuclear Information System (INIS)

    Kim, Sang Dug; Song, Dong Joo

    2005-01-01

    The aerodynamic effects of leading-edge accretion can raise important safety concerns since the formulation of ice causes severe degradation in aerodynamic performance as compared with the clean airfoil. The objective of this study is to develop a numerical simulation strategy for predicting the particle trajectory around an MS-0317 airfoil in the test section of the NASA Glenn Icing Research Tunnel and to investigate the impingement characteristics of droplets on the airfoil surface. In particular, predictions of the mean velocity and turbulence diffusion using turbulent flow solver and continuous random walk method were desired throughout this flow domain in order to investigate droplet dispersion. The collection efficiency distributions over the airfoil surface in simulations with different numbers of droplets, various integration time-steps and particle sizes were compared with experimental data. The large droplet impingement data indicated the trends in impingement characteristics with respect to particle size; the maximum collection efficiency located at the upper surface near the leading edge, and the maximum value and total collection efficiency were increased as the particle size was increased. The extent of the area impinged on by particles also increased with the increment of the particle size, which is similar as compared with experimental data

  5. Numerical investigation of mist/air impingement cooling on ribbed blade leading-edge surface.

    Science.gov (United States)

    Bian, Qingfei; Wang, Jin; Chen, Yi-Tung; Wang, Qiuwang; Zeng, Min

    2017-12-01

    The working gas turbine blades are exposed to the environment of high temperature, especially in the leading-edge region. The mist/air two-phase impingement cooling has been adopted to enhance the heat transfer on blade surfaces and investigate the leading-edge cooling effectiveness. An Euler-Lagrange particle tracking method is used to simulate the two-phase impingement cooling on the blade leading-edge. The mesh dependency test has been carried out and the numerical method is validated based on the available experimental data of mist/air cooling with jet impingement on a concave surface. The cooling effectiveness on three target surfaces is investigated, including the smooth and the ribbed surface with convex/concave columnar ribs. The results show that the cooling effectiveness of the mist/air two-phase flow is better than that of the single-phase flow. When the ribbed surfaces are used, the heat transfer enhancement is significant, the surface cooling effectiveness becomes higher and the convex ribbed surface presents a better performance. With the enhancement of the surface heat transfer, the pressure drop in the impingement zone increases, but the incremental factor of the flow friction is smaller than that of the heat transfer enhancement. Copyright © 2017 Elsevier Ltd. All rights reserved.

  6. Shock and vibration protection of submerged jet impingement cooling systems: Theory and experiment

    International Nuclear Information System (INIS)

    Haji Hosseinloo, Ashkan; Tan, Siow Pin; Yap, Fook Fah; Toh, Kok Chuan

    2014-01-01

    In the recent years, advances in high power density electronics and computing systems have pushed towards more advanced thermal management technologies and higher-capacity cooling systems. Among different types of cooling systems, jet impingement technology has gained attention and been widely used in different industries for its adaptability, cooling uniformity, large heat capacity, and ease of its localization. However, these cooling systems may not function properly in dynamically harsh environment inherent in many applications such as land, sea and air transportation. In this research article, a novel double-chamber jet impingement cooling system is fabricated and its performance is studied in harsh environment. Using the authors' previous studies, isolators with optimum properties are selected to ruggedize the chassis containing the cooling chamber against shock and random vibration. Experiments are conducted on both hard-mounted and isolated chassis and the cooling performance of the system is assessed using the inlet, and impingement surface temperatures of the cooling chamber. The experimental results show the isolation system prevents any failure that otherwise would occur, and also does not compromise the thermal performance of the system. - Highlights: • A novel double-chamber jet impingement cooling system was designed and fabricated. • Comprehensive set of random vibration and shock tests are conducted. • The isolation system proved to protect the cooling system properly against mechanical failure. • Cooling system performance was not significantly affected by the input random vibration and shock

  7. Influence of microscale surface modification on impinging flow heat transfer performance

    NARCIS (Netherlands)

    Taha, T.J.; Lefferts, Leonardus; van der Meer, Theodorus H.

    2016-01-01

    An experimental approach has been used to investigate the influence of a thin layer of carbon nanotubes (CNTs) on the convective heat transfer performance under impinging flow conditions. A successful synthesis of CNT layers was achieved using a thermal catalytic vapor deposition process (TCVD) on

  8. Subacute posteromedial impingement of the ankle in athletes: MR imaging evaluation and ultrasound guided therapy

    International Nuclear Information System (INIS)

    Messiou, Christina; Robinson, Philip; O'Connor, Philip J.; Grainger, Andrew

    2006-01-01

    To describe the use of MR imaging and efficacy of ultrasound-guided steroid injection in the diagnosis and management of athletes with clinical posteromedial impingement of the ankle. A retrospective analysis of imaging findings on MR was undertaken in nine elite athletes with clinical posteromedial ankle impingement. MR studies from six professional athletes with posterolateral pain were also reviewed as an imaging control group. The two reviewing radiologists were blinded to the clinical details and the proportion of control and study subjects. The nine study athletes also underwent diagnostic ultrasound and ultrasound-guided injection of steroid and anaesthetic into the posteromedial capsular abnormality. Follow-up was by telephone interview. Posteromedial capsular thickening was seen only in athletes with posteromedial impingement (7/9). Posteromedial synovitis was present in all athletes with posteromedial impingement; however, posterior and posterolateral synovitis was also seen in these athletes. Mild posteromedial synovitis was present in two control athletes. Ultrasound identified abnormal posteromedial soft tissue thickening deep to tibialis posterior between the medial malleolus and talus in all nine athletes. After injection all athletes returned to their previous level of sport, with eight of the nine not experiencing any residual or recurrent symptoms. If MR imaging excludes significant coexistent abnormality, ultrasound can localise posteromedial soft tissue abnormality and guide injection therapy, allowing return to athletic activity without surgical intervention. (orig.)

  9. The scapular dyskinesis test

    DEFF Research Database (Denmark)

    Christiansen, David Høyrup; Møller, Anders Damgaard; Vestergaard, Jesper Medom

    2017-01-01

    tests with which to identify scapular dyskinesis. PURPOSE OF THE STUDY: To evaluate intrarater and interrater reliability and predictive value of the Scapular Dyskinesis Test (SDT) in patients with subacromial impingement syndrome. METHODS: Forty-five patients with subacromial impingement syndrome were...

  10. Hip kinematics and kinetics in persons with and without cam femoroacetabular impingement during a deep squat task.

    Science.gov (United States)

    Bagwell, Jennifer J; Snibbe, Jason; Gerhardt, Michael; Powers, Christopher M

    2016-01-01

    Previous studies have indicated that hip and pelvis kinematics may be altered during functional tasks in persons with femoroacetabular impingement. The purpose of this study was to compare hip and pelvis kinematics and kinetics during a deep squat task between persons with cam femoroacetabular impingement and pain-free controls. Fifteen persons with cam femoroacetabular impingement and 15 persons without cam femoroacetabular impingement performed a deep squat task. Peak hip flexion, abduction, and internal rotation, and mean hip extensor, adductor, and external rotator moments were quantified. Independent t-tests (αsquat descent compared to the control group, resulting in a more anteriorly tilted pelvis at the time peak hip flexion (12.5° (SD 17.1°) vs. 23.0° (SD 12.4°); P=0.024). The decreased hip internal rotation observed in persons with cam femoroacetabular impingement may be the result of bony impingement. Furthermore, the decrease in posterior pelvis tilt may contribute to impingement by further approximating the femoral head-neck junction with the acetabulum. Additionally, decreased hip extensor moments suggest that diminished hip extensor muscle activity may contribute to decreased posterior pelvis tilt. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT) Collector with Jet Impingement and Compound Parabolic Concentrator (CPC).

    Science.gov (United States)

    Jaaz, Ahed Hameed; Hasan, Husam Abdulrasool; Sopian, Kamaruzzaman; Kadhum, Abdul Amir H; Gaaz, Tayser Sumer; Al-Amiery, Ahmed A

    2017-08-01

    This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT) collector and compound parabolic concentrators (CPC) on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m² and an ambient temperature of 33.5 °C). It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV) module at 1:30 p.m. The short-circuit current I SC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.

  12. Outdoor Performance Analysis of a Photovoltaic Thermal (PVT Collector with Jet Impingement and Compound Parabolic Concentrator (CPC

    Directory of Open Access Journals (Sweden)

    Ahed Hameed Jaaz

    2017-08-01

    Full Text Available This paper discusses the effect of jet impingement of water on a photovoltaic thermal (PVT collector and compound parabolic concentrators (CPC on electrical efficiency, thermal efficiency and power production of a PVT system. A prototype of a PVT solar water collector installed with a jet impingement and CPC has been designed, fabricated and experimentally investigated. The efficiency of the system can be improved by using jet impingement of water to decrease the temperature of the solar cells. The electrical efficiency and power output are directly correlated with the mass flow rate. The results show that electrical efficiency was improved by 7% when using CPC and jet impingement cooling in a PVT solar collector at 1:00 p.m. (solar irradiance of 1050 W/m2 and an ambient temperature of 33.5 °C. It can also be seen that the power output improved by 36% when using jet impingement cooling with CPC, and 20% without CPC in the photovoltaic (PV module at 1:30 p.m. The short-circuit current ISC of the PV module experienced an improvement of ~28% when using jet impingement cooling with CPC, and 11.7% without CPC. The output of the PV module was enhanced by 31% when using jet impingement cooling with CPC, and 16% without CPC.

  13. Current standard rules of combined anteversion prevent prosthetic impingement but ignore osseous contact in total hip arthroplasty.

    Science.gov (United States)

    Weber, Markus; Woerner, Michael; Craiovan, Benjamin; Voellner, Florian; Worlicek, Michael; Springorum, Hans-Robert; Grifka, Joachim; Renkawitz, Tobias

    2016-12-01

    In this prospective study of 135 patients undergoing cementless total hip arthroplasty (THA) we asked whether six current definitions of combined anteversion prevent impingement and increase postoperative patient individual impingement-free range-of-motion (ROM). Implant position was measured by an independent, external institute on 3D-CT performed six weeks post-operatively. Post-operative ROM was calculated using a CT-based algorithm detecting osseous and/or prosthetic impingement by virtual hip movement. Additionally, clinical ROM was evaluated pre-operatively and one-year post-operatively by a blinded observer. Combined component position of cup and stem according to the definitions of Ranawat, Widmer, Dorr, Hisatome and Yoshimine inhibited prosthetic impingement in over 90 %, while combined osseous and prosthetic impingement still occurred in over 40 % of the cases. The recommendations by Jolles, Widmer, Dorr, Yoshimine and Hisatome enabled higher flexion (p ≤ 0.001) and internal rotation (p ≤ 0.006). Clinically, anteversion rules of Widmer and Yoshimine provided one-year post-operatively statistically but not clinically relevant higher internal rotation (p ≤0.034). Standard rules of combined anteversion detect prosthetic but fail to prevent combined osseous and prosthetic impingement in THA. Future models will have to account for the patient-individual anatomic situation to ensure impingement-free ROM.

  14. Impingement syndrome of the shoulder following double row suture anchor technique for arthroscopic rotator cuff repair: a case report

    Directory of Open Access Journals (Sweden)

    Rambani Rohit

    2009-06-01

    Full Text Available Abstract Introduction Arthroscopic repair of the rotator cuff is a demanding surgery. Accurate placement of anchors is key to success. Case presentation A 38-year-old woman received arthroscopic repair of her rotator cuff using a double row suture anchor technique. Postoperatively, she developed impingement syndrome which resulted from vertical displacement of a suture anchor once the shoulder was mobilised. The anchor was removed eight weeks following initial surgery and the patient had an uneventful recovery. Conclusion Impingement syndrome following arthroscopic repair of the rotator cuffs using double row suture anchor has not been widely reported. This is the first such case where anchoring has resulted in impingement syndrome.

  15. Pollutant emission and noise radiation from open and impinging inverse diffusion flames

    International Nuclear Information System (INIS)

    Choy, Y.S.; Zhen, H.S.; Leung, C.W.; Li, H.B.

    2012-01-01

    Highlights: ► The effect of burner geometry (d air and S) on inverse diffusion flames is studied. ► With fixed air/fuel supplies, a smaller d air curtails NO x emission but augments noise radiation. ► With fixed air/fuel supplies, a larger S reduces NO x emission but increases noise radiation. ► Both NO x emission and noise radiation are maximum under stoichiometric combustion. ► Impinging flames are nosier than corresponding open flames due to the mirror effect of the plate. -- Abstract: This paper reports an experimental investigation of the pollutant emission and noise radiation characteristics of both open and impinging inverse diffusion flames (IDFs), produced by five burners of different air port diameter (d air = 5, 6 and 6.84 mm) and air-to-fuel spacing (S = 8, 11.5 and 15 mm). The effects of d air , S, overall equivalence ratio φ and nozzle-to-plate spacing H on the pollutant emissions of CO and NO x and the noise radiation are examined. The results show that at fixed air flow rate, a smaller d air curtails NO x emission but augments noise radiation, indicative of a role played by turbulence, which tends to decrease pollutant emission and increase noise radiation. A larger S reduces NO x emission but increases noise radiation, indicating that different flame zones may be responsible for pollutant emission and noise radiation. When the IDF is under stoichiometric φ = 1.6, both the NO x emission and noise radiation are highest, as a result of maximum heat release rate. A comparison of EINO x for the open and impinging IDFs shows that the impinging IDFs emit more NO x probably due to the absence of NO reburning. The impinging IDFs have higher noise radiation than the corresponding open IDFs. A higher level of noise radiation from the impinging IDFs is observed as the target plate is brought closer to the burner.

  16. MR patterns of rotator cuff impingement lesions and histopathologic correlation of cadaver tendons

    International Nuclear Information System (INIS)

    Rafii, M.; Firooznia, H.; Minkoff, J.; Sherman, O.; Schinella, R.; Weinreb, J.C.; Golimbu, C.; Zazlav, K.

    1989-01-01

    This paper reports shoulder MR examinations of 250 patients retrospectively evaluated and correlated with surgical/arthrographic results in 68 patients and with clinical data in all for assessment of the signal pattern and the configuration of rotator cuff lesions. MR-histopathologic evaluation of the supraspinatus tendon of 8 cadaver shoulders was also correlated with these findings. MR imaging had a sensitivity of 92% in the diagnosis of cuff tears. The most common and accurate criterion for a tear was a tendinous defect, characterized by intense signal on T2-weighted images; less often the torn region consisted of an extremely degenerated and attenuated tendon or was obscured by scar. Presence of secondary findings was mandatory for diagnosis in the latter group. Signal pattern associated with tendonitis varied, and in some simulated that of tendon degeneration (fatty infiltration and fibrillation) or cellular proliferation observed on anatomic specimens. Associated tendinous enlargement and subacromial-subdeltoid bursitis in these patients best correlated with the severity of clinical and surgical findings

  17. Survival of fishes after impingement on traveling screens at Hudson River power plants

    International Nuclear Information System (INIS)

    Muessig, P.H.; Hutchison, J.B.; King, L.R.; Ligotino, R.J.; Daley, M.

    1988-01-01

    The survival of Hudson River fishes, juveniles and adults, after they had been impinged on continuously rotated traveling screens at the Bowline Point and Danskammer Point power plants was examined. Survival of principal species was similar at the two plants, and estimates of survival improved as monitoring stress was reduced. Adjusted for survival of control fish, survival over 84-108 h after fish were recovered from the screens was highest for Atlantic tomcod, striped bass, and white perch (50-90%) and lowest for bay anchovy, alewife, and blueback herring; other species showed intermediate survival. Survival of striped bass and white perch was positively correlated with water temperature in winter and with conductivity in spring and fall. Continual rotation of the screens, which shortens the average time that fish are impinged, increased survival over that associated with intermittent rotation. 24 refs., 9 figs., 4 tabs

  18. Survey of fish impingement at power plants in the United States. Volume I. The Great Lakes

    International Nuclear Information System (INIS)

    Sharma, R.K.; Freeman, R.F. III.

    1977-03-01

    Impingement of fish at cooling-water intakes of 20 power plants located on the Great Lakes has been surveyed and data are presented. Descriptions of site, plant, and intake design and operation are provided. Reports in this volume summarize impingement data for individual plants in tabular and histogram formats. Information was available from differing sources such as the utilities themselves, public documents, regulatory agencies, and others. Thus, the extent of detail in the reports varies greatly from plant to plant. Histogram preparation involved an extrapolation procedure that has inadequacies. The reader is cautioned in the use of information presented in this volume to determine intake-design acceptability or intensity of impacts on ecosystems. No conclusions are presented herein; data comparisons are made in Volume IV

  19. Survey of fish impingement at power plants in the United States. Volume II. Inland waters

    International Nuclear Information System (INIS)

    Freeman, R.F. III; Sharma, R.K.

    1977-03-01

    Impingement of fish at cooling-water intakes of 33 power plants located on inland waters other than the Great Lakes has been surveyed and data are presented. Descriptions of site, plant, and intake design and operation are provided. Reports in this volume summarize impingement data for individual plants in tabular and histogram formats. Information was available from differing sources such as the utilities themselves, public documents, regulatory agencies, and others. Thus, the extent of detail in the reports varies greatly from plant to plant. Histogram preparation involved an extrapolation procedure that has inadequacies. The reader is cautioned in the use of information presented in this volume to determine intake-design acceptability or intensity of impacts on ecosystems. No conclusions are presented herein; data comparisons are made in Volume IV

  20. Configurable double-sided modular jet impingement assemblies for electronics cooling

    Science.gov (United States)

    Zhou, Feng; Dede, Ercan Mehmet

    2018-05-22

    A modular jet impingement assembly includes an inlet tube fluidly coupled to a fluid inlet, an outlet tube fluidly coupled to a fluid outlet, and a modular manifold having a first distribution recess extending into a first side of the modular manifold, a second distribution recess extending into a second side of the modular manifold, a plurality of inlet connection tubes positioned at an inlet end of the modular manifold, and a plurality of outlet connection tubes positioned at an outlet end of the modular manifold. A first manifold insert is removably positioned within the first distribution recess, a second manifold insert is removably positioned within the second distribution recess, and a first and second heat transfer plate each removably coupled to the modular manifold. The first and second heat transfer plates each comprise an impingement surface.

  1. Arthroscopic treatment of impingement of the ankle reduces pain and enhances function

    DEFF Research Database (Denmark)

    Rasmussen, S; Hjorth Jensen, C

    2002-01-01

    A consecutive series of 105 patients with a median age of 35 (16-62) years who were operated on with arthroscopic resection for impingement of the ankle using standardized technique without distraction is presented. All patients complained of painful dorsiflexion and had failed to respond to cons...... synovectomy and intravenous antibiotics. In one patient persistent symptoms were recorded. Ankle arthroscopy yielded good results in the treatment of anterior impingement of the ankle as it effectively reduced pain and enhanced function....... of pain. Gait was improved in 30/41 patients and 22 resumed sporting activities. The results were graded excellent in 67, good in 25, fair in six and poor in seven patients. There were four deep infections and one synovial fistula in this series. The deep infections all responded well to arthroscopic...

  2. Hybrid RANS/LES of flow and heat transfer in round impinging jets

    International Nuclear Information System (INIS)

    Kubacki, Slawomir; Dick, Erik

    2011-01-01

    Fluid flow and convective heat transfer predictions are presented of round impinging jets for several combinations of nozzle-plate distances H/D = 2, 6 and 13.5 (where D is the nozzle diameter) and Reynolds numbers Re = 5000, 23,000 and 70,000 with the newest version of the k-ω model of and three hybrid RANS/LES models. In the RANS mode of the hybrid RANS/LES models, the k-ω model is recovered. Three formulations are considered to activate the LES mode. The first model is similar to the hybrid models of and . The turbulent length scale is replaced by the grid size in the destruction term of the k-equation and in the definition of the RANS eddy viscosity. As grid size, a maximum measure of the hexahedral grid cell is used. The second model has the same k-equation, but the eddy viscosity is the minimum of the k-ω eddy viscosity and the Smagorinsky eddy viscosity, following a proposal by . The Smagorinsky eddy viscosity is formed with the cube root of the cell volume. The third model has, again, the same k-equation, but has an eddy viscosity which is an intermediate between the eddy viscosities of the first and second models. This is reached by using the cube root of the cell volume in the eddy viscosity formula of the first model. The simulation results are compared with experimental data for the high Reynolds number cases Re = 23,000 and Re = 70,000 and LES data for the low-Reynolds number case Re = 5000. The Reynolds numbers are defined with the nozzle diameter and the bulk velocity at nozzle outlet. At low nozzle-plate distance (the impingement plate is in the core of the jet), turbulent kinetic energy is overpredicted by RANS in the stagnation flow region. This leads to overprediction of the heat transfer rate along the impingement plate in the impact zone. At high nozzle-plate distance (the impingement plate is in the mixed-out region of the jet), the turbulence mixing is underpredicted by RANS in the shear layer of the jet which gives a too high length of

  3. Cam Femoroacetabular Impingement as a Possible Explanation of Recalcitrant Anterior Knee Pain.

    Science.gov (United States)

    Sanchis-Alfonso, Vicente; Tey, Marc; Monllau, Joan Carles

    2016-01-01

    We present a case of a patient with chronic anterior knee pain (AKP) recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI) at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patients with Cam FAI. This functional femoral rotation could provoke a patellofemoral imbalance that may be, in theory, responsible for patellofemoral pain in this particular patient. In our case, Cam FAI resolution was related to the resolution of AKP.

  4. Cam Femoroacetabular Impingement as a Possible Explanation of Recalcitrant Anterior Knee Pain

    Directory of Open Access Journals (Sweden)

    Vicente Sanchis-Alfonso

    2016-01-01

    Full Text Available We present a case of a patient with chronic anterior knee pain (AKP recalcitrant to conservative treatment who returned to our office for severe hip pain secondary to Cam femoroacetabular impingement (Cam FAI at 10 months after the onset of knee pain. This case highlights the fact that the main problem is not in the patella but in the hip in some patients with AKP. We hypothesize that there is an external femoral rotation in order to avoid the impingement and therefore the hip pain in patients with Cam FAI. This functional femoral rotation could provoke a patellofemoral imbalance that may be, in theory, responsible for patellofemoral pain in this particular patient. In our case, Cam FAI resolution was related to the resolution of AKP.

  5. Flow induced on a salt waterbody due to the impingement of a freshwater drop

    Science.gov (United States)

    Benouaguef, Islam; Amah, Edison; Musunuri, Naga; Blackmore, Denis; Fischer, Ian; Singh, Pushpendra

    2017-11-01

    The particle image velocimetry (PIV) and planar laser-induced fluorescence (PLIF) techniques are used to study the flow induced on the surface of a salt waterbody when a drop impinges on the surface. The measurements show that the impingement of a fresh water drop causes a strong axisymmetric solutocapillary flow about the vertical line passing through the center of impact. The fluid directly below the center of impact rises upward, and near the surface it moves away from the center of impact. The flow, which develops within a fraction of second after the impact, persists for several seconds and the volume of water circulated is two orders of magnitude larger than the volume circulated when a freshwater drop falls on a freshwater body.

  6. Flow field characteristics of impinging sweeping jets: TR-PIV measurement

    Science.gov (United States)

    Wen, Xin; Peng, Di; Liu, Yingzheng; Tang, Hui

    2017-11-01

    Influence of Reynolds number of sweeping jets on its impinging flow fields was extensively investigated in a water tank. Toward this end, a fluidic oscillator was specially designed to produce spatially sweeping jets which imping on a flat plate. Six Reynolds numbers were tested by controlling the supply flow rate of the fluidic oscillator. Impinging flow fields were captured by time-resolved Particle Image Velocimetry (TR-PIV) measurement. Reference signals were extracted from the flow fields for phase reconstruction. The oscillating flow fields with super-harmonic frequency at different regions were discussed in term of the phase-averaged velocity, vorticity and turbulent velocity. Dynamic mode decomposition (DMD) was used to capture the most-energetic flow patterns with distinct frequencies. By projecting the phase-averaged flow fields onto a reduced basis of DMD modes, the phase correlation between the distinct flow patterns were analyzed under different Reynolds numbers.

  7. Study of microburst-induced wind flow and its effects on cube-shaped buildings using numerical and experimental simulations of an impinging jet

    Science.gov (United States)

    Sengupta, Anindya

    Microbursts are a major cause of concern for structures both on ground as well as those in air, namely aircrafts. The velocity profile of a microburst is completely different compared to natural boundary-layer wind profiles. The current research is directed to simulation of microburst phenomenon using an impinging jet model. This research reports the first 3D numerical simulation of microbursts and its effects on buildings. Broadly the major accomplishments of the current research can be focused in three major directions. In the first case, extensive research on velocity profiles of the wall jet that is formed after jet impingement has been conducted experimentally. The main motivation was to develop empirical equations for boundary layer growth based on experimental data, using hot-wire, PIV and pressure rake. Numerical simulations were carried out with different turbulence models so as to find the best turbulence model to simulate this kind of flow. In the second case, both mean and peak loads on building models under static microburst wind loadings were studied, using both experimental as well as numerical techniques. Parametric study by varying the height of jet impingement, jet exit velocities and size of building models was conducted. It was found that the large eddy simulation (LES) produced results in excellent agreement with the experimental data. The flow field around the building model was obtained using PIV and comparisons were made with the LES results. Thirdly, and the most important part of this research work was to simulate a translating microburst and study the loads on buildings using a moving impinging jet. Numerical simulation was validated with the experimental data for one jet translation speed. LES results again matched the experimental data for translating microburst loads on building, with reference to the drag and lift coefficients. The peak loads predicted by LES were within experimental limits. Effects of increased jet translation speeds

  8. Pixel signal intensity analysis of anterior cruciate ligament grafts in knees with and without intercondylar roof impingement

    International Nuclear Information System (INIS)

    Howell, S.M.; Berns, G.S.; Farley, T.E.; Clark, J.A.

    1990-01-01

    This paper determines if intercondylar roof (IR) impingement produces quantitative, regionalized, and time-dependent differences in the pixel signal intensity (PSI) of anterior cruciate ligament (ACL) grafts. Patients with hamstring autografts were placed into two groups: inpinged (n = 14) and unimpinged (n = 18). MR images were obtained at 3, 6, 9, and over 12 months after operation in the unimpinged group and at 22 months in the impinged group. The PSI was measured along the proximal, middle, and distal thirds of the graft. The PSI was greater in the impinged knees in the distal (P < .008) and middle thirds (P < .009) of the graft, but there was no difference in the proximal third. In the unimpinged group, the signal in all three zones did not change from 3 to 12 months after operation. The tibial tunnel placement was more anterior in the impinged knees (P < .001). Stability (P < .012) and knee extension (P < .003) were better in the unimpinged knees

  9. Microjet impingement followed by scanning electron microscopy as a qualitative technique to compare cellular adhesion to various biomaterials.

    Science.gov (United States)

    Richards, R G; ap Gwynn, I; Bundy, K J; Rahn, B A

    1995-12-01

    Adhesion of cells to biomaterial surfaces is one of the major factors which mediates their biocompatibility. Quantitative or qualitative cell adhesion measurements would be useful for screening new implant materials. Microjet impingement has been evaluated by scanning electron microscopy, to determine to what extent it measures cell adhesion. The shear forces of the impingement, on the materials tested here, are seen to be greater than the cohesive strength of the cells in the impinged area, causing their rupture. The cell bodies are removed during impingement, leaving the sites of adhesion and other cellular material behind. Thus the method is shown not to provide quantification of cell adhesion forces for the metals and culture plastic tested. It is suggested that with highly adherent biomaterials, the distribution and patterns of these adhesion sites could be used for qualitative comparisons for screening of implant surfaces.

  10. Cryogenic Impinging Jets Subjected to High Frequency Transverse Acoustic Forcing in a High Pressure Environment

    Science.gov (United States)

    2016-07-27

    generated by a Fluke 292 arbitrary waveform generator. The signal generator was then fed to two Trek PZD2000A high- voltage amplifiers that drove two...Processes of Impinging Jet Injectors,” NASA Propulsion Engineering Research Center, vol. 2, N94-23042, 1993, pp.69-74. 8 Li, R., and Ashgriz...Instability,” NASA SP-194, 1972 V. Appendix A Figure A1. Instantaneous images of an acoustic cycle for the PAN 5 condition. A large group of

  11. Evaluation of liquid droplet impingement erosion by micro-scale fracture analysis

    International Nuclear Information System (INIS)

    Kitajima, Yasumi; Hagiwara, Tsuyoshi; Jimbo, Masakazu; Endo, Tetsuo

    2008-01-01

    Several estimation methods based on round-robin experiments and/or actual plant experiences have been used to estimate erosion by liquid drop impingement (LDI). However, in recent years, due to developments on computer technology, it is possible to utilize large scale computational analyses. This study proposes a method for the evaluation of LDI erosion by means of computational fracture analysis using results (diameters, velocity, or speed of drops) of fluid dynamics analysis. (author)

  12. Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy-a systematic review.

    Science.gov (United States)

    Haldane, Chloe E; Ekhtiari, Seper; de Sa, Darren; Simunovic, Nicole; Ayeni, Olufemi R

    2017-08-01

    The purpose of this systematic review is to report current preoperative assessment for femoroacetabular impingement (FAI) including physical examination and imaging modalities prior to hip arthroscopy, and report current imaging measures used in the diagnosis of FAI. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, non-operative treatment, preoperative assessment including physical examination and imaging prior to hip arthroscopy were abstracted. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies criteria. Sixty-eight studies of fair quality evidence that involved a total of 5125 patients (5400 hips) were included. In total, 56% of all patients were male and mean age was 36 years (SD ± 10.0). Within physical examination, FADIR impingement testing was reported in 57% of patients. All included studies reported plain radiographic imaging as a component of preoperative assessment with anterior-posterior pelvis view being the most commonly reported view, followed by the cross-table lateral and Dunn views. Magnetic resonance imaging was obtained for 52% of included patients and computed tomography for 26% of patients. The most commonly reported measure within imaging for the diagnosis of cam type impingement was alpha angle (66%), whereas for pincer type impingement, the cross-over sign (48%) was most reported. Preoperative assessment is underreported in the FAI literature. Improved reporting is warranted to develop a more consistent and validated diagnostic algorithm for FAI to enhance patient selection. Level of evidence : Level IV, Systematic Review of Level I-IV Studies.

  13. Preoperative physical examination and imaging of femoroacetabular impingement prior to hip arthroscopy—a systematic review

    Science.gov (United States)

    Haldane, Chloe E.; Ekhtiari, Seper; de SA, Darren; Simunovic, Nicole

    2017-01-01

    Abstract The purpose of this systematic review is to report current preoperative assessment for femoroacetabular impingement (FAI) including physical examination and imaging modalities prior to hip arthroscopy, and report current imaging measures used in the diagnosis of FAI. The electronic databases MEDLINE, EMBASE and PubMed were searched and screened in duplicate for relevant studies. Data regarding patient demographics, non-operative treatment, preoperative assessment including physical examination and imaging prior to hip arthroscopy were abstracted. Study quality was assessed in duplicate using the Methodological Index for Non-Randomized Studies criteria. Sixty-eight studies of fair quality evidence that involved a total of 5125 patients (5400 hips) were included. In total, 56% of all patients were male and mean age was 36 years (SD ± 10.0). Within physical examination, FADIR impingement testing was reported in 57% of patients. All included studies reported plain radiographic imaging as a component of preoperative assessment with anterior–posterior pelvis view being the most commonly reported view, followed by the cross-table lateral and Dunn views. Magnetic resonance imaging was obtained for 52% of included patients and computed tomography for 26% of patients. The most commonly reported measure within imaging for the diagnosis of cam type impingement was alpha angle (66%), whereas for pincer type impingement, the cross-over sign (48%) was most reported. Preoperative assessment is underreported in the FAI literature. Improved reporting is warranted to develop a more consistent and validated diagnostic algorithm for FAI to enhance patient selection. Level of evidence: Level IV, Systematic Review of Level I–IV Studies. PMID:28948032

  14. Zero Secular Torque on Asteroids from Impinging Solar Photons in the YORP Effect: A Simple Proof

    Science.gov (United States)

    Rubincam, David Perry; Paddack, Stephen J.

    2010-01-01

    YORP torques, where "YORP" stands for "Yarokovsky-O'Keefe-Radzievskii-Paddack." arise mainly from sun light reflected off a Solar System object and the infrared radiation emi tted by it. We show here, through the most elementary demonstration that we Can devise, that secular torques from impinging solar photons are generally negligible and thus cause little secular evolution of an asteroid's obliquity or spin rate.

  15. Software documentation and user's manual for fish-impingement sampling design and estimation method computer programs

    International Nuclear Information System (INIS)

    Murarka, I.P.; Bodeau, D.J.

    1977-11-01

    This report contains a description of three computer programs that implement the theory of sampling designs and the methods for estimating fish-impingement at the cooling-water intakes of nuclear power plants as described in companion report ANL/ES-60. Complete FORTRAN listings of these programs, named SAMPLE, ESTIMA, and SIZECO, are given and augmented with examples of how they are used

  16. Plume Impingement to the Lunar Surface: A Challenging Problem for DSMC

    Science.gov (United States)

    Lumpkin, Forrest; Marichalar, Jermiah; Piplica, Anthony

    2007-01-01

    The President's Vision for Space Exploration calls for the return of human exploration of the Moon. The plans are ambitious and call for the creation of a lunar outpost. Lunar Landers will therefore be required to land near predeployed hardware, and the dust storm created by the Lunar Lander's plume impingement to the lunar surface presents a hazard. Knowledge of the number density, size distribution, and velocity of the grains in the dust cloud entrained into the flow is needing to develop mitigation strategies. An initial step to acquire such knowledge is simulating the associated plume impingement flow field. The following paper presents results from a loosely coupled continuum flow solver/Direct Simulation Monte Carlo (DSMC) technique for simulating the plume impingement of the Apollo Lunar module on the lunar surface. These cases were chosen for initial study to allow for comparison with available Apollo video. The relatively high engine thrust and the desire to simulate interesting cases near touchdown result in flow that is nearly entirely continuum. The DSMC region of the flow field was simulated using NASA's DSMC Analysis Code (DAC) and must begin upstream of the impingement shock for the loosely coupled technique to succeed. It was therefore impossible to achieve mean free path resolution with a reasonable number of molecules (say 100 million) as is shown. In order to mitigate accuracy and performance issues when using such large cells, advanced techniques such as collision limiting and nearest neighbor collisions were employed. The final paper will assess the benefits and shortcomings of such techniques. In addition, the effects of plume orientation, plume altitude, and lunar topography, such as craters, on the flow field, the surface pressure distribution, and the surface shear stress distribution are presented.

  17. Novel two-phase jet impingement heat sink for active cooling of electronic devices

    International Nuclear Information System (INIS)

    Oliveira, Pablo A. de; Barbosa, Jader R.

    2017-01-01

    Highlights: • Novel jet-based heat sink integrates the evaporator and the expansion device. • The system was tested with a small-scale oil-free R-134a compressor. • The thermodynamic performance of the cooling system was evaluated experimentally. • The single-jet maximum cooling capacity was 160 W, with a COP of 2.3 and a η 2nd of 8%. • Maximum heat transfer coefficient of 15 kW m −2 K −1 and surface temperature of 30 °C. - Abstract: This work presents a compact vapor compression cooling system equipped with a small-scale oil-free R-134a compressor and a jet-impingement-based heat sink that integrates the evaporator and the expansion device into a single unit. At the present stage of the development, a single orifice was used to generate the high-speed two-phase impinging jet on the heated surface. The effects of the compressor piston stroke, applied thermal load and orifice diameter on the system performance were quantified. The thermodynamic performance of the system was evaluated in terms of the temperature of the heated surface, impinging jet heat transfer coefficient, several system thermal resistances, coefficient of performance, second-law efficiency and second-law ratio. The coefficient of performance of the new refrigeration system increased with the cooling capacity, justifying its application in the removal of large thermal loads. The maximum system cooling capacity with a single jet was approximately 160 W, which was achieved with an orifice diameter of 500 μm and operation at a full compressor piston stroke. This condition corresponded to a COP of 2.3, a second-law efficiency of 8.0%, a jet impingement heat transfer coefficient above 15 kW m −2 K −1 and a heater surface temperature of approximately 30 °C.

  18. The Role of Femoroacetabular Impingement in Core Muscle Injury/Athletic Pubalgia: Diagnosis and Management

    OpenAIRE

    Strosberg, David S.; Ellis, Thomas J.; Renton, David B.

    2016-01-01

    Chronic groin pain in athletes represents a major diagnostic and therapeutic challenge in sports medicine. Two recognized causes of inguinal pain in the young adult athlete are core muscle injury/athletic pubalgia (CMI/AP) and femoroacetabular impingement (FAI). CMI/AP and FAI were previously considered to be two distinct entities, however recent studies have suggested both entities to frequently coincide in the athlete with groin pain. This article briefly discusses the role of femoroaceta...

  19. Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies

    OpenAIRE

    Mayne, E; Memarzadeh, A; Raut, P; Arora, A; Khanduja, Vikas

    2017-01-01

    $\\textbf{Objectives}$ The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field. $\\textbf{Methods}$ The Cochrane and PubMed libraries were searched for any publications using the terms ‘hip’, ‘muscle’, ‘strength’, and ‘measurement’ in the ‘Title, Abstract, Keywords’ field. A further sea...

  20. Influence of thermal gradient on gas turbine combustor wall using impingement/effusion cooling techniques: CHT CFD predictions

    Directory of Open Access Journals (Sweden)

    A. M. El-jummah

    2017-04-01

    Full Text Available Internal wall heat transfer relevant to impingement/effusion cooling techniques was investigated using conjugate heat transfer (CHT computational fluid dynamics (CFD with ANSYS Fluent and ICEM commercial software. This work concentrates on the development of CHT CFD design procedures that are applicable to combustor wall and turbine blade heat transfer optimisation in gas turbine (GT. It specifically modelled and compares two configuration which are specifically relevant to the impingement and effusion holes density n (m-2 and is the ratio of the hole pitch X2. The configurations investigated are equal and unequal impingement and effusion holes density n (m-2, respectively, whereby in each case the variation in the number of cooling holes were carried out. The ratio of impingement and effusion number of holes/m2 (or hole density n, investigated were impingement/effusion: 4306/4306 and 1076/4306, respectively. The geometries were for impingement wall, hole pitch X to diameter D, X/D ratio of ~ 11 but different number of holes N for both n geometries, at a constant offset effusion wall, hole X/D of 4.7 of the same N for both the two configurations. The model geometries have a constant impingement gap of 8 mm with both impingement and effusion walls at 6.35 mm thick Nimonic - 75 material and were computed for varied air mass flux G from 0.1 - 0.94 kg/sm2. Symmetrical applications were employed in modelling each of the geometry, whereby for the impingement hole, only quarter of one hole was modelled, while for the effusion side the holes were either quarter or half modelled. The two n geometries were computed with k - ɛ turbulence model using standard wall functions, which also applies to all G. The predicted locally surface X2 (or hole square area average heat transfer coefficient (HTC h values compared with with previously published experimental data showed good agreement. The reduced internal gap flow recirculation with reduced heat transfer to

  1. Effect of guide wall on jet impingement cooling in blade leading edge channel

    International Nuclear Information System (INIS)

    Zhao, Qing-Yang; Chung, Heeyoon; Choi, Seok Min; Cho, Hyung Hee

    2016-01-01

    The characteristics of fluid flow and heat transfer, which are affected by the guide wall in a jet impinged leading edge channel, have been investigated numerically using three-dimensional Reynolds-averaged Navier-Stokes analysis via the shear stress transport turbulence model and gamma theta transitional turbulence model. A constant wall heat flux condition has been applied to the leading edge surface. The jet-to-surface distance is constant, which is three times that of the jet diameter. The arrangement of the guide wall near the jet hole is set as a variable. Results presented in this study include the Nusselt number contour, velocity vector, streamline with velocity, and local Nusselt number distribution along the central line on the leading edge surface. The average Nusselt number and average pressure loss between jet nozzle and channel exit are calculated to assess the thermal performance. The application of the guide wall is aimed at improving heat transfer uniformity on the leading edge surface. Results indicated that the streamwise guide wall ensures the vertical jet impingement flow intensity and prevents the flow after impingement to reflux into jet flow. Thus, a combined rectangular guide wall benefits the average heat transfer, thermal performance and heat transfer distribution uniformity

  2. Breakup characteristics of power-law liquid sheets formed by two impinging jets

    International Nuclear Information System (INIS)

    Bai, Fuqiang; Diao, Hai; Chang, Qing; Wang, Endong; Du, Qing; Zhang, Mengzheng

    2014-01-01

    The breakup characteristics of the shear-thinning power-law liquid sheets formed by two impinging jets have been investigated with the shadowgraph technique. This paper focuses on the effects of spray parameters (jet velocity), physical parameters (viscosity) and geometry parameters (impinging angle and nozzle cross-sectional shape) on the breakup behaviors of liquid sheets. The breakup mode, sheet length and expansion angle of the sheet are extracted from the spray images obtained by a high speed camera. Impinging angle and Weber number play the similar roles in promoting the breakup of liquid sheets. With the increase of jet velocity, five different breakup modes are observed and the expansion angle increases consistently after the closed-rim mode while the sheet length first increases and then decreases. But there exists a concave consisting of a fierce drop and a second rising process on the sheet length curve for the fluid with smaller viscosity. Different nozzle cross-sectional shapes emphasize significant effects on the sheet length and expansion angle of liquid sheets. At a fixed Weber number, the liquid sheet with greater viscosity has a greater sheet length and a smaller expansion angle due to the damping effect of viscosity. (papers)

  3. Fish impingement at estuarine power stations and its significance to commercial fishing

    International Nuclear Information System (INIS)

    Turnpenny, A.W.H.

    1989-01-01

    The abstraction of cooling water (CW) at power stations sited on tidal waters inevitably leads to mortalities of some fish which are drawn in with the CW supply and become impinged on the intake screens. These fish are predominantly 0- or 1-group juveniles which, owing to their small size, are unable to resist intake currents. Commercial fishermen often object to the fact that juvenile fish are killed in this way. Their concern stems from the fact that in order to protect stocks, commercial fishing is restricted to fish which are above a statutory minimum landing size, whereas the majority of fish killed by impingement are below this size. This Report considers the significance of impingement mortalities at four estuarine sites in Britain for six commercially important species. Life tables are used to establish expected survival trajectories for each species and to compute reproductive potential. Each fish killed on intake screens is then considered in terms of the fraction of the reproductive potential of a single adult at maturity, and is ascribed an 'adult equivalent' value. Total catches of mixed juveniles and adults are then presented as 'adult equivalent' values. (author)

  4. Oblique radiograph for the detection of bone spurs in anterior ankle impingement

    International Nuclear Information System (INIS)

    Dijk, Niek C. van; Wessel, Ronald N.; Tol, Johannes L.; Maas, M.

    2002-01-01

    Objective: The aim of this study was to develop a radiographic view to detect anteromedial talotibial osteophytes that remain undetected on standard radiographs. Design and patients: In 10 cadaver specimens the maximal size was measured of anteromedial tibial osteophytes that remain undetected on a standard lateral radiograph projection, due to the presence of the anteromedial tibial rim. The average projection of the most prominent anterolateral tibial rim over the anteromedial rim was found to be 7.3 mm. A 7 mm barium-clay osteophyte was attached to this anteromedial rim of the distal tibia. Anteromedial osteophytes become most prominent on an oblique view, in which the radiographic beam is tilted into a 45 craniocaudal direction with the leg in 30 external rotation. This oblique view was compared with the findings of arthroscopic surgery in 25 consecutive patients with anterior ankle impingement syndrome. Results: Medially located tibial and talar osteophytes remained undetected on a standard lateral projection and became visible on the oblique anteromedial impingement (AMI) radiograph. Anterolateral tibial and talar osteophytes were well detected on a standard lateral radiograph projection but were invisible on the AMI view. There was a high correlation between the location of the osteophyte and the location of symptoms and the findings at arthroscopy. Conclusion: A combination of lateral and oblique radiographs can be used to differentiate between anteromedial and anterolateral bony ankle impingement. (orig.)

  5. Turbulent flow and heat transfer from a slot jet impinging on a moving plate

    International Nuclear Information System (INIS)

    Chattopadhyay, Himadri; Saha, Sujoy K.

    2003-01-01

    The flow field due to an impinging jet over a moving surface at a moderately high Reynolds number, emanating from a rectangular slot nozzle has been computed using the large eddy simulation technique. A dynamic subgrid-scale stress model has been used for the small scales of turbulence. The velocity of the impinging surface perpendicular to the jet velocity has been varied up to two times the jet velocity at the nozzle exit. Turbulence quantities such as kinetic energy, production rate of turbulent kinetic energy and the Reynolds stresses are calculated for different surface velocities. It has been observed that, while the turbulent kinetic energy increases with increasing velocity of the impinging surface, production rate of turbulence initially increases with increasing surface velocity and then comes down. By analyzing the components of turbulent production it was found that P 33 is the dominant term up to the surface velocity of one unit and when the surface velocity is two times the jet velocity at the nozzle exit, the major contribution to turbulence production comes from P 13 and partly from P 11 . Heat transfer from the plate initially increases with non-dimensional surface velocity up to 1.2 and then comes down

  6. Physical examination tests for the diagnosis of femoroacetabular impingement. A systematic review.

    Science.gov (United States)

    Pacheco-Carrillo, Aitana; Medina-Porqueres, Ivan

    2016-09-01

    Numerous clinical tests have been proposed to diagnose FAI, but little is known about their diagnostic accuracy. To summarize and evaluate research on the accuracy of physical examination tests for diagnosis of FAI. A search of the PubMed, SPORTDiscus and CINAHL databases was performed. Studies were considered eligible if they compared the results of physical examination tests to those of a reference standard. Methodological quality and internal validity assessment was performed by two independent reviewers using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. The systematic search strategy revealed 298 potential articles, five of which articles met the inclusion criteria. After assessment using the QUADAS score, four of the five articles were of high quality. Clinical tests included were Impingement sign, IROP test (Internal Rotation Over Pressure), FABER test (Flexion-Abduction-External Rotation), Stinchfield/RSRL (Resisted Straight Leg Raise) test, Scour test, Maximal squat test, and the Anterior Impingement test. IROP test, impingement sign, and FABER test showed the most sensitive values to identify FAI. The diagnostic accuracy of physical examination tests to assess FAI is limited due to its heterogenecity. There is a strong need for sound research of high methodological quality in this area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Surgical dislocation of the hip in patients with femoroacetabular impingement: Surgical techniques and our experience

    Directory of Open Access Journals (Sweden)

    Mladenović Marko

    2015-01-01

    Full Text Available Background/Aim. Arthrosis of the hip is the most common cause of a hip joint disorders. The aim of this study was to present our experience in the application of a safe surgical dislocation of the hip in patients with minor morphological changes in the hip joint, which, through the mechanism of femoroacetabular impingement, cause damage to the acetabular labrum and adjacent cartilage as an early sign of the hip arthrosis. Methods. We have operated 51 patients with different morphological bone changes in the hip area and resultant soft tissue damage of the acetabular labrum and its adjacent cartilage. Surgical technique that we applied in this group of patients, was adapted to our needs and capabilities and it was minimaly modified compared to the original procedure. Results. The surgical technique presented in this paper, proved to be a good method of treatment of bone and soft tissue pathomorphological changes of the hip in patients with femoroacetabular impingement. We had no cases with avascular necrosis of the femoral head, and two patients had nonunion of the greater trochanter, 9 patients developed paraarticular ossification, without subjective symptoms, while 3 patients suffered from postoperative pain in the groin during more energetic physical activities. Conclusion. Utilization of our partly modified surgical technique of controlled and safe dislocation of the hip can solve all the bone and soft tissue problems in patients with femoroacetibular impingement to stop already developed osteoarthritis of the hip or to prevent mild form of it.

  8. Numerical study of a hybrid jet impingement/micro-channel cooling scheme

    International Nuclear Information System (INIS)

    Barrau, Jérôme; Omri, Mohammed; Chemisana, Daniel; Rosell, Joan; Ibañez, Manel; Tadrist, Lounes

    2012-01-01

    A new hybrid jet impingement/micro-channel cooling scheme is studied numerically for use in high-heat-flux thermal management of electronic and power devices. The device is developed with the objective of improving the temperature uniformity of the cooled object. A numerical model based on the k–ω SST turbulent model is developed and validated experimentally. This model is used to carry out a parametrical characterization of the heat sink. The study shows that variations in key parameters of jet impingement and micro-channel technologies allow for the cooling scheme to obtain a wide range of temperature profiles for the cooled object. - Highlights: ► A new hybrid cooling scheme is numerically studied. ► The cooling scheme combines the benefits of jet impingement and micro-channel flows. ► The numerical model is validated by comparison with experimental results. ► The temperature distribution can be adapted to the needs of the cooled system.

  9. An analytical wall-function for recirculating and impinging turbulent heat transfer

    International Nuclear Information System (INIS)

    Suga, K.; Ishibashi, Y.; Kuwata, Y.

    2013-01-01

    Highlights: ► Improvement of the analytical wall-function is proposed. ► Strain parameter dependency is introduced to the prescribed eddy viscosity profile of the analytical wall-function. ► The model performance is evaluated in turbulent pipe, channel, back-step, abrupt expansion pipe and plane impinging flows. ► Generally improved heat transfer is obtained in all the test cases with the standard k-e model. -- Abstract: The performance of the analytical wall-function (AWF) of Craft et al. [Craft, T.J., Gerasimov, A.V., Iacovides, H., Launder, B.E., 2002, Progress in the generalisation of wall-function treatments. Int. J. Heat Fluid Flow 23, 148–160.] is improved for predicting turbulent heat transfer in recirculating and impinging flows. Since constant parameters of the eddy viscosity formula were used to derive the AWF, the prediction accuracy of the original AWF tends to deteriorate in complex flows where those parameters need changing according to the local turbulence. To overcome such shortcomings, the present study introduces a functional behaviour on the strain parameter into the coefficient of the eddy viscosity of the AWF. The presently modified version of the AWF is validated in turbulent heat transfer of pipe flows, channel flows, back-step flows, pipe flows with abrupt expansion and plane impinging slot jets. The results confirm that the present modification successfully improves the performance of the original AWF for all the flows and heat transfer tested

  10. Numerical study of metal foam heat sinks under uniform impinging flow

    International Nuclear Information System (INIS)

    Andreozzi, A; Bianco, N; Iasiello, M; Naso, V

    2017-01-01

    The ever-increasing demand for performance improvement and miniaturization of electronics has led to a significant generation of waste heat that must be dissipated to ensure a reliable device operation. The miniaturization of the components complicates this task. In fact, reducing the heat transfer area, at the same required heat rate, it is necessary to increase the heat flux, so that the materials operate in a temperature range suitable to its proper functioning. Traditional heat sinks are no longer capable of dissipating the generated heat and innovative approaches are needed to address the emerging thermal management challenges. Recently, heat transfer in open-cell metal foams under an impinging jet has received attention due to the considerable heat transfer potential of combining two cooling technologies: impinging jet and porous medium. This paper presents a numerical study on Finned Metal Foam (FMF) and Metal Foam (MF) heat sinks under impinging air jet cooling. The analysis is carried out by means of the commercial software COMSOL Multiphysics®. The purpose is to analyze the thermal performance of the metal foam heat sink, finned or not, varying its geometric parameters. Results are presented in terms of predicted dissipated heat rate, convective heat transfer coefficient and pressure losses. (paper)

  11. Investigation of Characteristics of Impinging Jet for 1/5-Scale ECC injection

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Byung Soo; Ko, Yung Joo; Bae, Hwang; Kwon, Tae Soon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    In ECCS of SMART reactor, safety injection pump discharges cooling water into the core to maintain the water level by filling the amount of loss of coolant under emergency situation such as SBLOCA. Once the ECCS starts to operate, the injected water will be impinged to the upper wall of core support barrel (CBS). And the water will fall along the wall forming liquid film or droplets as shown in Fig. 1(b) due to high Reynolds number. The breakup and film flow will be bypassed by high temperature and pressure steam-water mixture cross flow from RCP discharge into the atmosphere through broken injection nozzle. Then, the flow phenomena in the downcomer is very complex situation with including jet impingement, jet breakup, liquid entrainment, steam condensation, counter-current flow and etc. In this study, the hydraulic features of impinging jet were investigated through visualization for full scale test for simulation of SMART ECC jet and SWAT test of 1/5 simulated test for ECCS of SMART reactor and measurement of the film width. And the scaling method for SWAT test was discussed considering jet break up and other phenomena

  12. Spray-Wall Impingement of Diesel-CNG Dual Fuel Jet using Schlieren Imaging Technique

    Directory of Open Access Journals (Sweden)

    Ismael Mhadi Abaker

    2014-07-01

    Full Text Available Natural gas is a low cost fuel with high availability in nature. However, it cannot be used by itself in conventional diesel engines due to its low flame speed and high ignition temperature. The addition of a secondary fuel to enhance the mixture formation and combustion process facilitate its wider use as an alternative fuel. An experimental study was performed to investigate the diesel-CNG dual fuel jet-wall impingement. A constant volume optical chamber was designed to facilitate maximum optical access for the study of the jet-wall impingement at different injection pressures, temperatures and injector-wall distances. The bottom plate of the test rig was made of aluminum (piston material and it was heated up to 500 K at ambient pressure. An injector driver was used to control the single-hole nozzle diesel injector combined with a natural gas injector. The injection timing of both injectors was synchronized with a camera trigger. The jet-wall impingement of diesel and diesel-CNG dual fuel jets was recorded with a high speed camera using Schlieren imaging technique and associated image processing software. The measurements of the jet radial penetration were higher in diesel-CNG dual fuel while the jet height travel along were higher in the case of diesel single fuel.

  13. [The relationship between chronic hip pain and femoroacetabular impingement: an evaluation with clinical signs and radiography].

    Science.gov (United States)

    Sahin, Namik; Atici, Teoman; Oztürk, Alpaslan; Ozkaya, Güven; Avcu, Bülent; Ozkan, Yüksel

    2011-12-01

    In this study, we investigated the rate of the clinical and radiographic findings of femoroacetabular impingement (FAI) in patients with chronic hip pain and compared the findings with those of a control group. The clinical and radiographic findings of FAI in 38 patients (group 1) having hip pain for more than three months were analyzed and compared with 42 controls (group 2). Internal rotation degrees were measured while the hips were at 90° flexion and impingement test was performed by rotating the hips internally at 90° flexion and adduction. The FAI findings were investigated on anteroposterior pelvis radiographs and cross-table lateral radiographs of the hip joint in both groups. The collum-diaphyseal angle, alpha angle and anterior offset ratio on the femoral side and the center-edge angle, acetabular index, extrusion index and crossover sign on the acetabular side were evaluated. The internal rotation degree of the painful hips were less than 20 degree in 18 (47.4%) patients in group 1 and in one (2.4%) patient in group 2 (pcam type FAI was 76.3% (n=29) in group 1 and 42.9% (n=18) in group 2 (p=0.002). Femoroacetabular impingement is one of the causes of chronic hip pain and if evaluated with suitable clinical and radiographic parameters, the rates of diagnosis may increase.

  14. Assessment of congruence and impingement of the hip joint in professional ballet dancers: a motion capture study.

    Science.gov (United States)

    Charbonnier, Caecilia; Kolo, Frank C; Duthon, Victoria B; Magnenat-Thalmann, Nadia; Becker, Christoph D; Hoffmeyer, Pierre; Menetrey, Jacques

    2011-03-01

    Early hip osteoarthritis in dancers could be explained by femoroacetabular impingements. However, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. Moreover, it is unknown whether the femoral head and acetabulum are congruent in typical dancing positions. The practice of some dancing movements could cause a loss of hip joint congruence and recurrent impingements, which could lead to early osteoarthritis. Descriptive laboratory study. Eleven pairs of female dancer's hips were motion captured with an optical tracking system while performing 6 different dancing movements. The resulting computed motions were applied to patient-specific hip joint 3-dimensional models based on magnetic resonance images. While visualizing the dancer's hip in motion, the authors detected impingements using computer-assisted techniques. The range of motion and congruence of the hip joint were also quantified in those 6 recorded dancing movements. The frequency of impingement and subluxation varied with the type of movement. Four dancing movements (développé à la seconde, grand écart facial, grand écart latéral, and grand plié) seem to induce significant stress in the hip joint, according to the observed high frequency of impingement and amount of subluxation. The femoroacetabular translations were high (range, 0.93 to 6.35 mm). For almost all movements, the computed zones of impingement were mainly located in the superior or posterosuperior quadrant of the acetabulum, which was relevant with respect to radiologically diagnosed damaged zones in the labrum. All dancers' hips were morphologically normal. Impingements and subluxations are frequently observed in typical ballet movements, causing cartilage hypercompression. These movements should be limited in frequency. The present study indicates that some dancing movements could damage the hip joint, which could lead to early osteoarthritis.

  15. Anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity in residual poliomyelitis.

    Science.gov (United States)

    Sung, Ki Hyuk; Chung, Chin Youb; Lee, Kyoung Min; Lee, Seung Yeol; Park, Moon Seok

    2013-09-01

    This study was performed to investigate anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity in patients with residual poliomyelitis and to investigate whether the severity of preoperative equinus deformity affected the occurrence of symptomatic anterior impingement. Twenty-seven consecutive patients (mean age, 43.8 ± 9.4 years) with residual poliomyelitis who underwent tendo-Achilles lengthening for equinus foot deformity were included. On lateral foot-ankle weight-bearing radiographs, the tibiocalcaneal angle, plantigrade angle, and McDermott grade were measured and the presence of anterior blocking spur was evaluated. Eleven patients (40.7%) had anterior ankle impingement on radiographic findings preoperatively and 24 patients (88.9%) at latest follow-up. There was a significant difference in McDermott grade between preoperative and latest follow-up (P poliomyelitis had anterior ankle impingement after tendo-Achilles lengthening for long-standing equinus deformity, and the presence of symptomatic anterior ankle impingement was significantly associated with the severity of the equinus deformity. Therefore, for residual poliomyelitis patients with severe long-standing equinus deformity, surgeons should consider the possibility of a subsequent anterior procedure for anterior impingement after tendo-Achilles lengthening. Level IV, retrospective case series.

  16. Impingement heat flux by dispersed molten metal fuel on a horizontal stainless steel structure

    International Nuclear Information System (INIS)

    Gabor, J.D.; Purviance, R.T.; Aeschlimann, R.W.; Spencer, B.W.

    1989-01-01

    Although the Integral Fast Reactor (IFR) possesses inherent safety features, an assessment of the consequences of melting of the metal fuel is necessary for risk analysis. As part of this effort an experimental study was conducted to determine the depths of sodium at 600 C required for pour streams of various molten uranium alloys (U, U-5 wt % Zr, U-10 wt % Zr, and U-10 wt % Fe) to break up and solidify. The quenched particulate material, which was in the shape of filaments and sheets, formed coolable beds because of the high void-age (∼0.9) and large particle size (∼10 mm). In a test with a 0.15-m sodium depth, the fragments from a pure uranium pour stream did not completely solidify but formed an agglomerated mass which did not fuse to the base plate. However, the agglomerated fragments of U-10 wt % Fe eutectic fused to the stainless steel base plate. An analysis of the temperature response of a 25-mm thick base plate was made by volume averaging the properties of the sodium and metal phases and assuming two semi-infinite solids coming into contact. Good agreement was obtained with the data during the initial 5 to 10 s of the contact period. 16 refs., 5 figs., 2 tabs

  17. Femoroacetabular impingement: bone marrow oedema associated with fibrocystic change of the femoral head and neck junction

    Energy Technology Data Exchange (ETDEWEB)

    James, S.L.J. [Department of Radiology, RNOH Stanmore, Stanmore, Middlesex (United Kingdom) and Department of Radiology, Royal Orthopaedic Hospital, Birmingham (United Kingdom)]. E-mail: jamesslj@email.com; Connell, D.A. [Department of Radiology, RNOH Stanmore, Stanmore, Middlesex (United Kingdom); O' Donnell, P. [Department of Radiology, RNOH Stanmore, Stanmore, Middlesex (United Kingdom); Saifuddin, A. [Department of Radiology, RNOH Stanmore, Stanmore, Middlesex (United Kingdom)

    2007-05-15

    Aim: To describe the association of bone marrow oedema adjacent to areas of fibrocystic change at the femoral head and neck junction in patients with femoroacetabular impingement. Materials and methods: The clinical and imaging findings in six patients with bone marrow oedema adjacent to an area of fibrocystic change at the femoral head and neck junction are presented. There were five males and one female (age range 19-42 years, mean age 34.5 years). Three patients were referred with a clinical suspicion of femoroacetabular impingement, two with suspected osteoid osteoma and one with a clinical diagnosis of sciatica. The volume of bone marrow oedema (grade 1: 0-25%, grade 2: 26-50%, grade 3: 51-75% and grade 4: 76-100% of the femoral neck width), presence of labral and articular cartilage abnormality, joint effusion, and femoral head and neck morphology were recorded. Results: Magnetic resonance imaging (MRI) identified fibrocystic change in the anterolateral aspect of the femoral head and neck junction in all cases (mean size 9 mm, range 5-14 mm, three multilocular and three unilocular cysts). The volume of oedema was variable (one grade 1, two grade 2, one grade 3 and two grade 4). All patients had abnormality of the anterosuperior labrum with five patients demonstrating chondral loss. An abnormal femoral head and neck junction was identified in five patients. Conclusion: The radiological finding of fibrocystic change at the anterosuperior femoral neck with or without bone marrow oedema should prompt the search for femoroacetabular impingement. Bone marrow oedema may rarely be identified adjacent to these areas of cystic change and should be considered in the differential diagnosis of bone marrow oedema in the femoral neck.

  18. Femoroacetabular impingement: bone marrow oedema associated with fibrocystic change of the femoral head and neck junction

    International Nuclear Information System (INIS)

    James, S.L.J.; Connell, D.A.; O'Donnell, P.; Saifuddin, A.

    2007-01-01

    Aim: To describe the association of bone marrow oedema adjacent to areas of fibrocystic change at the femoral head and neck junction in patients with femoroacetabular impingement. Materials and methods: The clinical and imaging findings in six patients with bone marrow oedema adjacent to an area of fibrocystic change at the femoral head and neck junction are presented. There were five males and one female (age range 19-42 years, mean age 34.5 years). Three patients were referred with a clinical suspicion of femoroacetabular impingement, two with suspected osteoid osteoma and one with a clinical diagnosis of sciatica. The volume of bone marrow oedema (grade 1: 0-25%, grade 2: 26-50%, grade 3: 51-75% and grade 4: 76-100% of the femoral neck width), presence of labral and articular cartilage abnormality, joint effusion, and femoral head and neck morphology were recorded. Results: Magnetic resonance imaging (MRI) identified fibrocystic change in the anterolateral aspect of the femoral head and neck junction in all cases (mean size 9 mm, range 5-14 mm, three multilocular and three unilocular cysts). The volume of oedema was variable (one grade 1, two grade 2, one grade 3 and two grade 4). All patients had abnormality of the anterosuperior labrum with five patients demonstrating chondral loss. An abnormal femoral head and neck junction was identified in five patients. Conclusion: The radiological finding of fibrocystic change at the anterosuperior femoral neck with or without bone marrow oedema should prompt the search for femoroacetabular impingement. Bone marrow oedema may rarely be identified adjacent to these areas of cystic change and should be considered in the differential diagnosis of bone marrow oedema in the femoral neck

  19. Multiple hereditary exostoses and ischiofemoral impingement: a case-control study

    International Nuclear Information System (INIS)

    Yoong, Philip; Mansour, Ramy; Teh, James L.

    2014-01-01

    To assess whether there is a significant difference in the ischiofemoral space in patients with multiple hereditary exostoses affecting the proximal femora compared to normal patients. Ischiofemoral impingement is an increasingly recognized cause of hip and buttock pain. This causes narrowing of the ischiofemoral space resulting in an abnormal quadratus femoris muscle. We performed a retrospective search for individuals with MHE with proximal femoral involvement on pelvic MRI over a 7-year period (2006-2013). Suitable patients were age- and sex-matched with a control group. The minimum ischiofemoral space (MIFS) was recorded in each hip, as was the presence of edema and atrophy of quadratus femoris and concomitant hip osteoarthrosis. MRI features suggestive of ischiofemoral impingement were defined as MIFS less than 10 mm or an abnormal quadratus femoris muscle. Twenty-one hips in 11 individuals with MHE were included in the study. A total of 42 hips were analyzed. The mean age was 37 years (range, 13-72 years) and 55 % were male. There was a significant difference (p < 0.05) in the MIHS in individuals with MHE (mean, 10.7 mm, range, 0-21 mm) compared to a control group (mean, 18.1 mm, range, 10.5-26.5 mm). MRI features suggestive of ischiofemoral impingement were seen in 13/21 (62 %) hips in the MHE group and 0/21 (0 %) in the control group. The reduced ischiofemoral space and associated quadratus femoris abnormalities in patients with MHE involving the proximal femora may account for hip/buttock symptoms in the absence of significant degenerative change. (orig.)

  20. Subscapulais injuries associated with acromiohumeral instability in patients with shoulder impingement syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Tae Young; Jeong, Hee Seok; Lee, Seung Jun; Jeong, Yeo Jin [Pusan National University Yangsan Hospital, Yangsan (Korea, Republic of)

    2017-07-15

    To evaluate the association of subscapularis (SSC) injuries with acromiohumeral instability (AHI) in patients with shoulder impingement syndrome with supraspinatus (SSP) tears. Pre-operative shoulder magnetic resonance images of 106 patients with subsequent arthroscopic confirmation of shoulder impingement syndrome were reviewed retrospectively. Patients with SSC injuries were divided into the following 3 groups: 1) those with no injury symbolized to the SSC[0] (n = 38), 2) those with partial injuries to the SSC[1] (n = 41), and 3) those with complete disruption of the SSC[2] (n = 27). AHI was categorized into 5 stages depending on the SSP lesions: partial tear or pretear tendinosis symbolized to the SSP[0] (n = 24) and according to retraction severity of the SSP tendon with complete tear such as SSP[1] (n = 19), SSP[2] (n = 27), SSP[3] (n = 29), and SSP[4] (n = 7). Also, AHI was divided into two groups such as the mild group summed with SSP plus SSP plus SSP and the severe group summed with SSP plus SSP, including 70 patients and 36 patients, respectively. Twenty-nine patients (63.0%) among 46 patients with SSC[0] and thirty-two patients (78.0%) among 41 patients with SSC[1] were related to mild AHI. Eighteen patients (66.7%) among 27 patients with SSC[2] were associated with severe AHI. The SSC injury groups were statistically significantly associated with AHI (estimate 0.207, standard error 0.057, p < 0.01). SSC injuries could be related to AHI in patients with shoulder impingement syndrome.

  1. Multiple hereditary exostoses and ischiofemoral impingement: a case-control study

    Energy Technology Data Exchange (ETDEWEB)

    Yoong, Philip; Mansour, Ramy; Teh, James L. [Nuffield Orthopaedic Centre, Department of Radiology, Oxford (United Kingdom)

    2014-09-15

    To assess whether there is a significant difference in the ischiofemoral space in patients with multiple hereditary exostoses affecting the proximal femora compared to normal patients. Ischiofemoral impingement is an increasingly recognized cause of hip and buttock pain. This causes narrowing of the ischiofemoral space resulting in an abnormal quadratus femoris muscle. We performed a retrospective search for individuals with MHE with proximal femoral involvement on pelvic MRI over a 7-year period (2006-2013). Suitable patients were age- and sex-matched with a control group. The minimum ischiofemoral space (MIFS) was recorded in each hip, as was the presence of edema and atrophy of quadratus femoris and concomitant hip osteoarthrosis. MRI features suggestive of ischiofemoral impingement were defined as MIFS less than 10 mm or an abnormal quadratus femoris muscle. Twenty-one hips in 11 individuals with MHE were included in the study. A total of 42 hips were analyzed. The mean age was 37 years (range, 13-72 years) and 55 % were male. There was a significant difference (p < 0.05) in the MIHS in individuals with MHE (mean, 10.7 mm, range, 0-21 mm) compared to a control group (mean, 18.1 mm, range, 10.5-26.5 mm). MRI features suggestive of ischiofemoral impingement were seen in 13/21 (62 %) hips in the MHE group and 0/21 (0 %) in the control group. The reduced ischiofemoral space and associated quadratus femoris abnormalities in patients with MHE involving the proximal femora may account for hip/buttock symptoms in the absence of significant degenerative change. (orig.)

  2. Extracapsular approach for arthroscopic treatment of femoroacetabular impingement: clinical and radiographic results and complications

    Directory of Open Access Journals (Sweden)

    Bruno Dutra Roos

    2015-08-01

    Full Text Available ABSTRACTOBJECTIVES: To evaluate the clinical and radiographic results and complications relating to patients undergoing arthroscopic treatment for femoroacetabular impingement by means of an extracapsular approach. METHODS: Between January 2011 and March 2012, 49 patients (50 hips underwent arthroscopic treatment for femoroacetabular impingement, performed by the hip surgery team of the Orthopedic Hospital of Passo Fundo, Rio Grande do Sul. Forty patients (41 hips fulfilled all the requirements for this study. The mean follow-up was 29.1 months. The patients were assessed clinically by means of the Harris Hip score, as modified by Byrd (MHHS, the Non-Arthritic Hip score (NAHS and the internal rotation of the hip. Their hips were also evaluated radiographically, with measurement of the CE angle, dimensions of the joint space, alpha angle, neck-head index, degree of arthrosis and presence of heterotopic ossification of the hip. RESULTS: Out of the 41 hips treated, 31 (75.6% presented good or excellent clinical results. There was a mean postoperative increase of 22.1 points for the MHHS, 21.5 for the NAHS and 16.4° for the internal rotation of the hip ( p< 0.001. Regarding the radiographic evaluation, correction to normal values was observed for the alpha angle and neck-head index, with a mean postoperative decrease of 32.9° and mean increase of 0.10, respectively ( p< 0.001. CONCLUSION: Arthroscopic treatment of femoroacetabular impingement by means of an extracapsular approach presented satisfactory clinical and radiographic results over a mean follow-up of 29.1 months, with few complications.

  3. The effect of dynamic femoroacetabular impingement on pubic symphysis motion: a cadaveric study.

    Science.gov (United States)

    Birmingham, Patrick M; Kelly, Bryan T; Jacobs, Robert; McGrady, Linda; Wang, Mei

    2012-05-01

    A link between femoroacetabular impingement and athletic pubalgia has been reported clinically. One proposed origin of athletic pubalgia is secondary to repetitive loading of the pubic symphysis, leading to instability and parasymphyseal tendon and ligament injury. Hypothesis/ The purpose of this study was to investigate the effect of simulated femoral-based femoroacetabular impingement on rotational motion at the pubic symphysis. The authors hypothesize that the presence of a cam lesion leads to increased relative symphyseal motion. Controlled laboratory study. Twelve hips from 6 fresh-frozen human cadaveric pelvises were used to simulate cam-type femoroacetabular impingement. The hips were held in a custom jig and maximally internally rotated at 90° of flexion and neutral adduction. Three-dimensional motion of the pubic symphysis was measured by a motion-tracking system for 2 states: native and simulated cam. Load-displacement plots were generated between the internal rotational torque applied to the hip and the responding motion in 3 anatomic planes of the pubic symphysis. As the hip was internally rotated, the motion at the pubic symphysis increased proportionally with the degrees of the rotation as well as the applied torque measured at the distal femur for both states. The primary rotation of the symphysis was in the transverse plane and on average accounted for more than 60% of the total rotation. This primary motion caused the anterior aspect of the symphyseal joint to open or widen, whereas the posterior aspect narrowed. At the torque level of 18.0 N·m, the mean transverse rotation in degrees was 0.89° ± 0.35° for the native state and 1.20° ± 0.41° for cam state. The difference between cam and the native groups was statistically significant (P pubalgia.

  4. Novel method for the measurement of liquid film thickness during fuel spray impingement on surfaces.

    Science.gov (United States)

    Henkel, S; Beyrau, F; Hardalupas, Y; Taylor, A M K P

    2016-02-08

    This paper describes the development and application of a novel optical technique for the measurement of liquid film thickness formed on surfaces during the impingement of automotive fuel sprays. The technique makes use of the change of the light scattering characteristics of a metal surface with known roughness, when liquid is deposited. Important advantages of the technique over previously established methods are the ability to measure the time-dependent spatial distribution of the liquid film without a need to add a fluorescent tracer to the liquid, while the measurement principle is not influenced by changes of the pressure and temperature of the liquid or the surrounding gas phase. Also, there is no need for non-fluorescing surrogate fuels. However, an in situ calibration of the dependence of signal intensity on liquid film thickness is required. The developed method can be applied to measure the time-dependent and two-dimensional distribution of the liquid fuel film thickness on the piston or the liner of gasoline direct injection (GDI) engines. The applicability of this technique was evaluated with impinging sprays of several linear alkanes and alcohols with different thermo-physical properties. The surface temperature of the impingement plate was controlled to simulate the range of piston surface temperatures inside a GDI engine. Two sets of liquid film thickness measurements were obtained. During the first set, the surface temperature of the plate was kept constant, while the spray of different fuels interacted with the surface. In the second set, the plate temperature was adjusted to match the boiling temperature of each fuel. In this way, the influence of the surface temperature on the liquid film created by the spray of different fuels and their evaporation characteristics could be demonstrated.

  5. Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies: A systematic review.

    Science.gov (United States)

    Mayne, E; Memarzadeh, A; Raut, P; Arora, A; Khanduja, V

    2017-01-01

    The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field. The Cochrane and PubMed libraries were searched for any publications using the terms 'hip', 'muscle', 'strength', and 'measurement' in the 'Title, Abstract, Keywords' field. A further search was performed using the terms 'femoroacetabular' or 'impingement'. The search was limited to recent literature only. A total of 29 articles were reviewed to obtain information on a number of variables. These comprised the type of device used for measurement, rater standardisation, the type of movements tested, body positioning and comparative studies of muscle strength in FAI versus normal controls. The studies found that hip muscle strength is lower in patients with FAI; this is also true for the asymptomatic hip in patients with FAI. Current literature on this subject is limited and examines multiple variables. Our recommendations for achieving reproducible results include stabilising the patient, measuring isometric movements and maximising standardisation by using a single tester and familiarising the participants with the protocol. Further work must be done to demonstrate the reliability of any new testing method.Cite this article: E. Mayne, A. Memarzadeh, P. Raut, A. Arora, V. Khanduja. Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies: A systematic review. Bone Joint Res 2017;6:66-72. DOI: 10.1302/2046-3758.61.BJR-2016-0081. © 2017 Khanduja et al.

  6. Rotator Cuff Calcific Tendinitis: Ultrasound-Guided Needling and Lavage Versus Subacromial Corticosteroids: Five-Year Outcomes of a Randomized Controlled Trial.

    Science.gov (United States)

    de Witte, Pieter Bas; Kolk, Arjen; Overes, Ferdinand; Nelissen, Rob G H H; Reijnierse, Monique

    2017-12-01

    Barbotage (needling and lavage) is often applied in the treatment of calcific tendinitis of the rotator cuff (RCCT). In a previously published randomized controlled trial, we reported superior clinical and radiological 1-year outcomes for barbotage combined with a corticosteroid injection in the subacromial bursa (SAIC) compared with an isolated SAIC. There are no trials with a midterm or long-term follow-up of barbotage available. To compare the 5-year results of 2 regularly applied treatments of RCCT: ultrasound (US)-guided barbotage combined with a SAIC (group 1) versus an isolated US-guided SAIC (group 2). Randomized controlled trial; Level of evidence, 1. Patients were randomly assigned to group 1 or 2 and evaluated before and after treatment at regular time points until 12 months and also at 5 years using the Constant score (CS), the Western Ontario Rotator Cuff Index (WORC), and the Disabilities of the Arm, Shoulder and Hand (DASH). The calcification location and size and Gärtner classification were assessed on radiographs. The rotator cuff condition was evaluated with US. Results were analyzed using t tests, linear regression, and a mixed model for repeated measures. Forty-eight patients were included (mean age, 52.0 ± 7.3 years; 25 [52%] female) with a mean baseline CS of 68.7 ± 11.9. After a mean follow-up of 5.1 ± 0.5 years, the mean CS was 90 (95% CI, 83.0-95.9) in group 1 versus 87 (95% CI, 80.5-93.5) in group 2 ( P = .58). The mean improvement in the CS in group 1 was 18 (95% CI, 12.3-23.0) versus 21 (95% CI, 16.2-26.2) in group 2 ( P = .32). There was total resorption in 62% of group 1 and 73% of group 2 ( P = .45). The US evaluation of the rotator cuff condition showed no significant differences between the groups. With the mixed model for repeated measures, taking into account the baseline CS and Gärtner classification, the mean treatment effect for barbotage was 6 (95% CI, -8.9 to 21.5), but without statistical significance. Follow-up scores

  7. Clinical outcomes assessment in clinical trials to assess treatment of femoroacetabular impingement

    DEFF Research Database (Denmark)

    Harris-Hayes, Marcie; McDonough, Christine M; Leunig, Michael

    2013-01-01

    Patient-reported outcome measures are an important component of outcomes assessment in clinical trials to assess the treatment of femoroacetabular impingement (FAI). This review of disease-specific measures and instruments used to assess the generic quality of life and physical activity levels...... developed recently and have not been established in the literature. Although currently used generic and activity-level measures have limitations, as well, they should be considered, depending on the specific goals of the study. Additional research is needed to assess the properties of these measures fully...

  8. Rapid PCR amplification using a microfluidic device with integrated microwave heating and air impingement cooling.

    Science.gov (United States)

    Shaw, Kirsty J; Docker, Peter T; Yelland, John V; Dyer, Charlotte E; Greenman, John; Greenway, Gillian M; Haswell, Stephen J

    2010-07-07

    A microwave heating system is described for performing polymerase chain reaction (PCR) in a microfluidic device. The heating system, in combination with air impingement cooling, provided rapid thermal cycling with heating and cooling rates of up to 65 degrees C s(-1) and minimal over- or under-shoot (+/-0.1 degrees C) when reaching target temperatures. In addition, once the required temperature was reached it could be maintained with an accuracy of +/-0.1 degrees C. To demonstrate the functionality of the system, PCR was successfully performed for the amplification of the Amelogenin locus using heating rates and quantities an order of magnitude faster and smaller than current commercial instruments.

  9. The Role of Femoroacetabular Impingement in Core Muscle Injury/Athletic Pubalgia: Diagnosis and Management.

    Science.gov (United States)

    Strosberg, David S; Ellis, Thomas J; Renton, David B

    2016-01-01

    Chronic groin pain in athletes represents a major diagnostic and therapeutic challenge in sports medicine. Two recognized causes of inguinal pain in the young adult athlete are core muscle injury/athletic pubalgia (CMI/AP) and femoroacetabular impingement (FAI). CMI/AP and FAI were previously considered to be two distinct entities; however, recent studies have suggested both entities to frequently coincide in the athlete with groin pain. This article briefly discusses the role of FAI in CMI/AP and the diagnosis and management of this complex disease.

  10. IMPINGEMENT COOLING OF A SEMI-CIRCULAR CONCAVE CHANNEL BY 2D AIR-JET

    Directory of Open Access Journals (Sweden)

    Serhan KÜÇÜKA

    1998-01-01

    Full Text Available This study provides a numerical solution to the flow in a cylindrical cavity of which the upper wall contains a twodimensional slot. The air injected through the slot impinges and diffuses laterally on the lower wall. The jet enfluxed through the slot is assumed to have uniform velocity and temperature, and the temperature at the lower wall is kept constant. The resulting Navier-Stokes equations are solved by transforming simpler algorithm into a form useably in cylindrical co-ordinate system. The effect of cavity curvature, and the height ratio on velocity and pressure distribution is analyzed. The jet Reynolds number ranged from 100 to 1500 in the analysis.

  11. Thermal performance analysis of optimized hexagonal finned heat sinks in impinging air jet

    Energy Technology Data Exchange (ETDEWEB)

    Yakut, Kenan, E-mail: kyakut@atauni.edu.tr [Department of Mechanical Engineering, Faculty of Engineering, Atatürk University, 25100, Erzurum (Turkey); Yeşildal, Faruk, E-mail: fayesildal@agri.edu.tr [Department of Mechanical Engineering, Faculty of Patnos Sultan Alparslan Natural Sciences and Engineering, Ağrı İbrahim Çeçen University, 04100, Ağrı (Turkey); Karabey, Altuğ, E-mail: akarabey@yyu.edu.tr [Department of Machinery and Metal Technology, Erciş Vocational High School, Yüzüncü Yıl University, 65400, Van (Turkey); Yakut, Rıdvan, E-mail: ryakut@kafkas.edu.tr [Department of Mechanical Engineering, Faculty of Engineering and Architecture, Kafkas University, 36100, Kars (Turkey)

    2016-04-18

    In this study, thermal performance analysis of hexagonal finned heat sinks which optimized according to the experimental design and optimization method of Taguchi were investigated. Experiments of air jet impingement on heated hexagonal finned heat sinks were carried out adhering to the L{sub 18}(2{sup 1*}3{sup 6}) orthogonal array test plan. Optimum geometries were determined and named OH-1, OH-2. Enhancement efficiency with the first law of thermodynamics was analyzed for optimized heat sinks with 100, 150, 200 mm heights of hexagonal fin. Nusselt correlations were found out and variations of enhancement efficiency with Reynolds number presented in η–Re graphics.

  12. The entrainment of air by water jet impinging on a free surface

    Energy Technology Data Exchange (ETDEWEB)

    Soh, Wee King [University of Wollongong, School of Mechanical, Materials and Mechatronics Engineering, Northfields Ave, NSW (Australia); Khoo, Boo Cheong [National University of Singapore, Department of Mechanical and Production Engineering, 10 Kent Ridge Crescent (Singapore); Yuen, W.Y. Daniel [BlueScope Steel Research, Port Kembla, NSW (Australia)

    2005-09-01

    High-speed cine and video photographs were used to capture the flow patterns of a column of water jet impinging into a pool of water. The impact results in air entrainment into water in the form of a void with no mixing between the water in the jet and the surrounding water. Conservation of fluid momentum shows that the rate of increase of the height of the air void depends on the drag coefficient of the jet front. By neglecting the frictional losses, the application of energy conservation yields an expression that relates the maximum height of the air void with the properties of the water jet. (orig.)

  13. Burnout in a high heat-flux boiling system with an impinging jet

    International Nuclear Information System (INIS)

    Monde, M.; Katto, Y.

    1978-01-01

    An experimental study has been made on the fully-developed nucleate boiling at atmospheric pressure in a simple forced-convection boiling system, which consists of a heated flat surface and a small, high-speed jet of water or of freon-113 impinging on the heated surface. A generalized correlation for burnout heat flux data, that is applied to either water or freon-113 is successfully evolved, and it is shown that surface tension has an important role for the onset of burnout phenomenon, not only in the ordinary pool boiling, but also in the present boiling system with a forced flow. (author)

  14. Rapid preparation of high electrochemical performance LiFePO4/C composite cathode material with an ultrasonic-intensified micro-impinging jetting reactor.

    Science.gov (United States)

    Dong, Bin; Huang, Xiani; Yang, Xiaogang; Li, Guang; Xia, Lan; Chen, George

    2017-11-01

    A joint chemical reactor system referred to as an ultrasonic-intensified micro-impinging jetting reactor (UIJR), which possesses the feature of fast micro-mixing, was proposed and has been employed for rapid preparation of FePO 4 particles that are amalgamated by nanoscale primary crystals. As one of the important precursors for the fabrication of lithium iron phosphate cathode, the properties of FePO 4 nano particles significantly affect the performance of the lithium iron phosphate cathode. Thus, the effects of joint use of impinging stream and ultrasonic irradiation on the formation of mesoporous structure of FePO 4 nano precursor particles and the electrochemical properties of amalgamated LiFePO 4 /C have been investigated. Additionally, the effects of the reactant concentration (C=0.5, 1.0 and 1.5molL -1 ), and volumetric flow rate (V=17.15, 51.44, and 85.74mLmin -1 ) on synthesis of FePO 4 ·2H 2 O nucleus have been studied when the impinging jetting reactor (IJR) and UIJR are to operate in nonsubmerged mode. It was affirmed from the experiments that the FePO 4 nano precursor particles prepared using UIJR have well-formed mesoporous structures with the primary crystal size of 44.6nm, an average pore size of 15.2nm, and a specific surface area of 134.54m 2 g -1 when the reactant concentration and volumetric flow rate are 1.0molL -1 and 85.74mLmin -1 respectively. The amalgamated LiFePO 4 /C composites can deliver good electrochemical performance with discharge capacities of 156.7mAhg -1 at 0.1C, and exhibit 138.0mAhg -1 after 100 cycles at 0.5C, which is 95.3% of the initial discharge capacity. Copyright © 2017. Published by Elsevier B.V.

  15. Numerical simulation of heat transfer and fluid flow of an impinging round jet of plasma into confined walls

    International Nuclear Information System (INIS)

    Ezato, Koichiro; Shimizu, Akihiko; Kunugi, Tomoaki.

    1995-01-01

    Numerical simulations are presented on the flow and heat transfer characteristics of an impinging round jet of argon plasma with atmospheric pressure. The target slab with finite thickness upon which plasma jet impinges is assumed to be as SiC which is a candidate material for plasma facing material of fusion reactor. The plasma jet is treated by use of a magnetohydrodynamics model that takes its two-temperature non-equilibrium state into account. The rear side of the target slab is assumed to be cooled by a gas-solid suspension impinging round jet. The result shows that the plasma is in non-equilibrium state in which the electron temperature is higher than the heavy particle in the outer region of plasma jet core and that the heat flux to the target slab is over 8 MW/m 2 in the region of the plasma jet core contacts. (author)

  16. Temperature-field measurements of a premixed butane/air circular impinging-flame using reference-beam interferometry

    International Nuclear Information System (INIS)

    Qi, J.A.; Leung, C.W.; Wong, W.O.; Probert, S.D.

    2006-01-01

    Reference-beam interferometry (RBI) was applied to study the axisymmetric temperature fields of a small-scale, low Reynolds-number, low-pressure and fuel-rich premixed butane/air circular-flame jet, when it was impinging vertically upwards onto a horizontal copper plate. By maintaining a Reynolds number, Re, of 500 and an equivalence ratio, φ, of 1.8, interferograms of the impinging-flame jet were obtained for various nozzle-to-plate-distances. Temperature fields of the flame were then determined using the inverse Abel transformation from the obtained interferograms. Temperatures at several locations were measured experimentally with a T-type thermocouple: they were used as a reference to help in the determination as well as the validation. In the present study, a non-contact method has been successfully developed to measure the temperature fields of a circular impinging gas-fired flame jet

  17. Numerical study of an impinging jet to a turbulent channel flow in a T-Junction configuration

    Science.gov (United States)

    Georgiou, Michail; Papalexandris, Miltiadis

    2016-11-01

    In this talk we report on Large Eddy Simulations of an impinging planar jet to a turbulent channel flow in a T-Junction configuration. Due to its capacity for mixing and heat transfer enhancement, this type of flow is encountered in various industrial applications. In particular, our work is related to the emergency cooling systems of pressurized water reactors. As is well known, this type of flow is dominated by a large separation bubble downstream the jet impingement location. Secondary regions of flow separation are predicted both upstream and downstream the impinging jet. We describe how these separation regions interact with the shear layer that is formed by the injection of the jet to the crossflow, and how they affect the mixing process. In our talk we further examine the influence of the jet's velocity to characteristic quantities of the jet, such as penetration length and expansion angle, as well as to the first and second-order statistics of the flow.

  18. The effect of nozzle collar on signle phase and boiling heat transfer by planar impinging jet

    International Nuclear Information System (INIS)

    Shin, Chang Hwan; Yim, Seong Hwan; Cho, Hyung Hee; Wu, Seong Je

    2005-01-01

    The water jet impingement cooling is one of the techniques to remove the heat from high heat flux equipment. Local heat transfer of the confined water impinging jet and the effect of nozzle collar to enhance the heat transfer are investigated in the free surface jet and submerged jet. Boiling is initiated from the farthest downstream and increase of the wall temperature is reduced with developing boiling, forming the flat temperature distributions. The reduction in the nozzle-to-surface distance for H/W≤1 causes significant increases and distribution changes of heat transfer. Developed boiling reduces the differences of heat transfer for various conditions. The nozzle collar is employed at the nozzle exit. The distances from heated surface to nozzle collar, H c are 0.25W, 0.5W and 1.0W. The liquid film thickness is reduced and the velocity of wall jet increases as decreased spacing of collar to heated surface. Heat transfer is enhanced for region from the stagnation to x/W∼8 in the free surface jet and to x/W∼5 in the submerged jet. For nucleate boiling region of further downstream, the heat transfer by the nozzle collar is decreased in submerged jet comparing with higher velocity condition. It is because the increased velocity by collar is de-accelerated downstream

  19. Large Eddy Simulation of a cooling impinging jet to a turbulent crossflow

    Science.gov (United States)

    Georgiou, Michail; Papalexandris, Miltiadis

    2015-11-01

    In this talk we report on Large Eddy Simulations of a cooling impinging jet to a turbulent channel flow. The impinging jet enters the turbulent stream in an oblique direction. This type of flow is relevant to the so-called ``Pressurized Thermal Shock'' phenomenon that can occur in pressurized water reactors. First we elaborate on issues related to the set-up of the simulations of the flow of interest such as, imposition of turbulent inflows, choice of subgrid-scale model and others. Also, the issue of the commutator error due to the anisotropy of the spatial cut-off filter induced by non-uniform grids is being discussed. In the second part of the talk we present results of our simulations. In particular, we focus on the high-shear and recirculation zones that are developed and on the characteristics of the temperature field. The budget for the mean kinetic energy of the resolved-scale turbulent velocity fluctuations is also discussed and analyzed. Financial support has been provided by Bel V, a subsidiary of the Federal Agency for Nuclear Control of Belgium.

  20. Large and Small Droplet Impingement Data on Airfoils and Two Simulated Ice Shapes

    Science.gov (United States)

    Papadakis, Michael; Wong, See-Cheuk; Rachman, Arief; Hung, Kuohsing E.; Vu, Giao T.; Bidwell, Colin S.

    2007-01-01

    Water droplet impingement data were obtained at the NASA Glenn Icing Research Tunnel (IRT) for four wings and one wing with two simulated ice shapes. The wings tested include three 36-in. chord wings (MS(1)-317, GLC-305, and a NACA 652-415) and a 57-in. chord Twin Otter horizontal tail section. The simulated ice shapes were 22.5- and 45-min glaze ice shapes for the Twin Otter horizontal tail section generated using the LEWICE 2.2 ice accretion program. The impingement experiments were performed with spray clouds having median volumetric diameters of 11, 21, 79, 137, and 168 mm. Comparisons to the experimental data were generated which showed good agreement for the clean wings and ice shapes at lower drop sizes. For larger drop sizes LEWICE 2.2 over predicted the collection efficiencies due to droplet splashing effects which were not modeled in the program. Also for the more complex glaze ice shapes interpolation errors resulted in the over prediction of collection efficiencies in cove and shadow regions of ice shapes.

  1. Conservative management of an elite ice hockey goaltender with femoroacetabular impingement (FAI): a case report

    Science.gov (United States)

    MacIntyre, Kyle; Gomes, Brendan; MacKenzie, Steven; D’Angelo, Kevin

    2015-01-01

    Objective: To detail the presentation of an elite male ice hockey goaltender with cam-type femoroacetabular impingement (FAI) and acetabular labral tears. This case will outline the prevalence, clinical presentation, imaging criteria, pathomechanics, and management of FAI, with specific emphasis on the ice hockey goaltender. Clinical Features: A 22-year old retired ice hockey goaltender presented to a chiropractor after being diagnosed by an orthopaedic surgeon with MRI confirmed left longitudinal and chondral flap acetabular labral tears and cam-type femoroacetabular impingement (FAI). As the patient was not a candidate for surgical intervention, a multimodal conservative treatment approach including manual therapy, electroacupuncture and rehabilitation exercises were implemented. Summary: FAI is prevalent in ice hockey players, particularly with goaltenders. Both skating and position-dependent hip joint mechanics involved in ice hockey may exacerbate or contribute to acquired and congenital forms of symptomatic FAI. As such, practitioners managing this population must address sport-specific demands in manual therapy, rehabilitation and physical training, to improve functional outcomes and prevent future injury. PMID:26816416

  2. Experimental study of curvature effects on jet impingement heat transfer on concave surfaces

    Directory of Open Access Journals (Sweden)

    Ying Zhou

    2017-04-01

    Full Text Available Experimental study of the local and average heat transfer characteristics of a single round jet impinging on the concave surfaces was conducted in this work to gain in-depth knowledge of the curvature effects. The experiments were conducted by employing a piccolo tube with one single jet hole over a wide range of parameters: jet Reynolds number from 27000 to 130000, relative nozzle to surface distance from 3.3 to 30, and relative surface curvature from 0.005 to 0.030. Experimental results indicate that the surface curvature has opposite effects on heat transfer characteristics. On one hand, an increase of relative nozzle to surface distance (increasing jet diameter in fact enhances the average heat transfer around the surface for the same curved surface. On the other hand, the average Nusselt number decreases as relative nozzle to surface distance increases for a fixed jet diameter. Finally, experimental data-based correlations of the average Nusselt number over the curved surface were obtained with consideration of surface curvature effect. This work contributes to a better understanding of the curvature effects on heat transfer of a round jet impingement on concave surfaces, which is of high importance to the design of the aircraft anti-icing system.

  3. Experimental investigation on the performance of an impinging jet solar air heater

    Directory of Open Access Journals (Sweden)

    T. Rajaseenivasan

    2017-03-01

    Full Text Available Investigation on an impinging jet solar air heater is performed and reported in this work. The air is supplied through an impinging jet pipe which contains the nozzles to distribute the air in the solar air heater. The air is released from the jet strikes the absorber plate which increases the heat transfer rate by creating turbulent flow in the collector. This study is focused on the parameters that affect the heat transfer characteristics and compared with conventional solar air heater. The system is examined by varying the angle of attack (0°, 10°, 20°, 30°, 60° and 90° and the nozzle diameter (3 mm, 5 mm and 7 mm in the air mass flow rate range of 0.012–0.016 kg/s. The study revealed that the highest performance is achieved with the 30° angle of attack, and the lowest performance is recorded with the 0°. The reduction in jet diameter increases the pressure loss in the collector. The better system performance is observed with the 5 mm diameter hole. The maximum thermal enhancement factor of 2.19 and efficiency of 55.8% are reached with the flow rate of 0.016 kg/s.

  4. Performance analysis of solar air heater with jet impingement on corrugated absorber plate

    Directory of Open Access Journals (Sweden)

    Alsanossi M. Aboghrara

    2017-09-01

    Full Text Available This paper deals with the experimental investigation outlet temperature and efficiency, of Solar Air heater (SAH. The experimental test set up designed and fabricated to study the effect of jet impingement on the corrugated absorber plate, through circular jets in a duct flow of solar air heater, and compared with conventional solar air heater on flat plat absorber. Under effect of mass flow rate (ṁ of air and solar radiation on outlet air temperature, and efficiency, are analyzed. Results show the flow jet impingement on corrugated plat absorber is a strong function of heat transfer enhancement. The present investigation concludes that the mass flow rate of air substantially influences the heat transfer on solar air heaters. And the thermal efficiency of proposed design duct is observed almost 14% more as compare to the smooth duct. At solar radiation 500–1000 (W/M2, 308 K ambient temperature and 0.01–0.03 (Kg/S mass flow rate

  5. Impingement drying for preparing dried apple pomace flour and its fortification in bakery and meat products.

    Science.gov (United States)

    Jung, Jooyeoun; Cavender, George; Zhao, Yanyun

    2015-09-01

    This study aimed to evaluate impingement drying (ID) as a rapid drying method to dry wet apple pomace (WAP) and to investigate the fortification of dried apple pomace flour (APF) or WAP in bakery and meat products. ID at ~110 °C reduced the moisture content of apple pomace from 80 % (wet basis) to 4.5 % within 3 h, compared with 24 h to 2.2 % using 40 °C forced-air drying and ~60 h to 2.3 % using freeze drying. Furthermore, ID enhanced the extractable phenolic compounds, allowing for a 58 % increase in total phenolic content (TPC) compared with wet pomace, a 110 % and 83 % higher than TPC in forced-air dried and freeze dried samples, respectively. The 15-20 % APF-fortified cookies were found to be ~44-59 % softer, ~30 % more chewy, and ~14 % moister than those of the control. WAP-fortified meat products had significantly higher dietary fiber content (0.7-1.8 % vs. 0.1-0.2 % in control) and radical scavenging activity than that of the control. These results suggest that impingement drying is a fast and effective method for preparing dried APF with highly retained bioactive compounds, and apple pomace fortified products maintained or even had improved quality.

  6. Numerical Investigation of Jet Impingement Heat Transfer on a Flat plate

    Directory of Open Access Journals (Sweden)

    Asem Nabadavis

    2016-12-01

    Full Text Available The numerical investigation emphasizes on studying the heat transfer characteristics when a high velocity air jet impinges upon a flat plate having constant heat flux. Numerical analysis has been conducted by solving conservation equations of momentum, mass and energy with two equations based k- ε turbulence model to determine the wall temperature and Nu of the plate considering the flow to be incompressible. It was found from the investigation that the heat transfer rate increases with the increase of Reynolds number of the jet (Rej. It was also found that there is an optimum value for jet distance to nozzle diameter ratio (H/d for maximum heat transfer when all the other parameters were kept fixed. Similar results as above were found when two jets of air were used instead of one jet keeping the mass flow rate constant. For a two jets case it was also found that heat transfer rate over the surface increases when the jets are inclined outward compared to vertical and inward jets and also there exists an optimum angle of jet for maximum heat transfer. Further investigation was carried out for different jetto-jet separation distance for a twin jet impingement model where it was noted that heat transfer is more distributed in case of larger values of L and the rate of heat transfer increases as the separation between the jet increases till a certain point after which the rate of heat transfer decreases.

  7. An experimental and theoretical investigation of spray characteristics of impinging jets in impact wave regime

    Science.gov (United States)

    Rodrigues, N. S.; Kulkarni, V.; Gao, J.; Chen, J.; Sojka, P. E.

    2015-03-01

    The current study focuses on experimentally and theoretically improving the characterization of the drop size and drop velocity for like-on-like doublet impinging jets. The experimental measurements were made using phase Doppler anemometry (PDA) at jet Weber numbers We j corresponding to the impact wave regime of impinging jet atomization. A more suitable dynamic range was used for PDA measurements compared to the literature, resulting in more accurate experimental measurements for drop diameters and velocities. There is some disagreement in the literature regarding the ability of linear stability analysis to accurately predict drop diameters in the impact wave regime. This work seeks to provide some clarity. It was discovered that the assumed uniform jet velocity profile was a contributing factor for deviation between diameter predictions based on models in the literature and experimental measurements. Analytical expressions that depend on parameters based on the assumed jet velocity profile are presented in this work. Predictions based on the parabolic and 1/7th power law turbulent profiles were considered and show better agreement with the experimental measurements compared to predictions based on the previous models. Experimental mean drop velocity measurements were compared with predictions from a force balance analysis, and it was observed that the assumed jet velocity profile also influences the predicted velocities, with the turbulent profile agreeing best with the experimental mean velocity. It is concluded that the assumed jet velocity profile has a predominant effect on drop diameter and velocity predictions.

  8. Efficacy of water spray protection against propane and butane jet fires impinging on LPG storage tanks

    Energy Technology Data Exchange (ETDEWEB)

    Shirvill, L.C. [Shell Global Solutions (UK), Chester (United Kingdom)

    2004-03-01

    Liquefied petroleum gas (LPG) storage tanks are often provided with water sprays to protect them in the event of a fire. This protection has been shown to be effective in a hydrocarbon pool fire but uncertainties remained regarding the degree of protection afforded in a jet fire resulting from a liquid or two-phase release of LPG. Two projects, sponsored by the Health and Safety Executive, have been undertaken to study, at full scale, the performance of a water spray system on an empty 13 tonne LPG vessel under conditions of jet fire impingement from nearby releases of liquid propane and butane. The results showed that a typical water deluge system found on an LPG storage vessel cannot be relied upon to maintain a water film over the whole vessel surface in an impinging propane or butane jet fire scenario. The deluge affects the fire itself, reducing the luminosity and smoke, resulting in a lower rate of wall temperature rise at the dry patches, when compared with the undeluged case. The results of these studies will be used by the HSE in assessing the risk of accidental fires on LPG installations leading to boiling liquid expanding vapour explosion (BLEVE) incidents. (Author)

  9. Bilateral iliopsoas muscle contracture and spinous process impingement in a German Shepherd dog.

    Science.gov (United States)

    Ragetly, Guillaume R; Griffon, Dominique J; Johnson, Ann L; Blevins, William E; Valli, Victor E

    2009-12-01

    To report diagnosis and treatment of bilateral iliopsoas muscle contracture in a dog with spinous process impingement. Case report. German Shepherd dog. A dog with chronic progressive lameness, flexion contracture of the coxofemoral joints, severe pain, and decreased femoral reflexes had severe spondylosis bridging the vertebral bodies from L1 to L4 and enlarged dorsal spinous processes from T8 to L6 with impingement and bony proliferation. Ultrasonographic and magnetic resonance imaging (MRI) findings were consistent with fibrosis, mineralization, and atrophy of the iliopsoas muscles bilaterally which was treated by staged tenectomy of the insertions of the iliopsoas muscles. Because of severe perivascular fibrosis, the femoral vessels required ligation. Bilateral iliopsoas muscle tenectomy improved gait and provided pain relief. Histologic findings were consistent with fibrotic myopathy. Slow progression of severe clinical signs observed bilaterally in this dog differs from previous reports of iliopsoas myopathy. Findings were similar to the fibrotic myopathy of the gracilis or semitendinosus muscles described in dogs. Iliopsoas muscle abnormalities should be considered in dogs with limited hip extension and pain. MRI is useful for diagnosing muscle fibrosis. Iliopsoas tenectomy may improve clinical function in dogs with fibrotic myopathy.

  10. Mucosal deformation from an impinging transonic gas jet and the ballistic impact of microparticles

    International Nuclear Information System (INIS)

    Hardy, M P; Kendall, M A F

    2005-01-01

    By means of a transonic gas jet, gene guns ballistically deliver microparticle formulations of drugs and vaccines to the outer layers of the skin or mucosal tissue to induce unique physiological responses for the treatment of a range of conditions. Reported high-speed imaging experiments show that the mucosa deforms significantly while subjected to an impinging gas jet from a biolistic device. In this paper, the effect of this tissue surface deformation on microparticle impact conditions is simulated with computational fluid dynamics (CFD) calculations. The microparticles are idealized as spheres of diameters 26.1, 39 and 99 μm and a density of 1050 kg m -3 . Deforming surface calculations of particle impact conditions are compared directly with an immobile surface case. The relative velocity and obliquity of the deforming surface decrease the normal component of particle impact velocity by up to 30% at the outer edge of the impinging gas jet. This is qualitatively consistent with reported particle penetration profiles in the tissue. It is recommended that these effects be considered in biolistic studies requiring quantified particle impact conditions

  11. Erosion onset of a cohesionless granular medium by an immersed impinging round jet

    Science.gov (United States)

    Brunier-Coulin, Florian; Cuéllar, Pablo; Philippe, Pierre

    2017-03-01

    Among different devices developed quite recently to quantify the resistance to erosion of natural soil within the broader context of dyke safety, the most commonly used is probably the jet erosion test in which a scouring crater is induced by impingement of an immersed water jet. A comprehensive experimental investigation on the jet erosion in the specific situation of a cohesionless granular material is presented here. The tests were performed by combining special optical techniques allowing for an accurate measurement of the scouring onset and evolution inside an artificially translucent granular sample. The impinging jet hydrodynamics are also analyzed, empirically validating the use of a self-similar theoretical framework for the laminar round jet. The critical conditions at the onset of erosion appear to be best described by a dimensionless Shields number based on the inertial drag force created by the fluid flow on the eroded particles rather than on the pressure gradients around them. To conclude, a tentative empirical model for the maximal flow velocity initiating erosion at the bottom of the scoured crater is put forward and discussed in the light of some preliminary results.

  12. Numerical Predictions of Enhanced Impingement Jet Cooling with Ribs and Pins in Co-Flow and Cross-Flow Configurations

    Directory of Open Access Journals (Sweden)

    A. M. El-Jummah

    2017-02-01

    Full Text Available Numerical calculations relevant to gas turbine internal wall heat transfer cooling were conducted using conjugate heat transfer (CHT computational Fluid Dynamics (CFD commercial codes. The CHT CFD predictions were carried out for impingement heat transfer with different types of obstacle walls (fins on the target surfaces. A 10 × 10 row of impingement air jet holes (or hole density n of 4306 m-2 was used, which gives ten rows of holes in the cross-flow direction and only one heat transfer enhancement obstacle per impingement jet was investigated. Previously, four different shaped obstacles were investigated experimentally and were used to validate the present predictions. The obstacle walls, which were equally spaced on the centreline between each impingement jet are of the co-flow and cross-flow configurations. The impingement jet pitch X to diameter D, X/D and gap Z to diameter, Z/D ratios were kept constant at 4.66 and 3.06 for X, Z and D of 15.24, 10.00 and 3.27 mm, respectively. The obstacles investigated were ribs and rectangular pin-fins shapes, using two obstacles height H to diameter, H/D ratio of 1.38 and 2.45. Computations were carried out for three different mass flux G of 1.08, 1.48 and 1.94 kg/sm2. Relative pressure loss ∆P/P and surface average heat transfer coefficient (HTC h predictions for the range of G, showed good agreement with the experimental results. The prediction also reveals that obstacles not only increases the turbulent flows, but also takes away most of the cooling heat transfer that produces the regions with highest thermal gradients. It also reduces the impingement gap downstream cross-flow.

  13. A mountain among molehills: removing an impinging large femoral neck osteochondroma in a man with hereditary multiple exostoses.

    LENUS (Irish Health Repository)

    Fitzgerald, Conall W R

    2014-01-01

    A 31-year-old man with a history of hereditary multiple exostoses (HME) presented with persistent right groin pain and reduced hip range of movement. Examination demonstrated a positive FADIR (flexion, adduction and internal rotation) test suggesting femoroacetabular impingement (FAI). Investigations showed multiple sessile osteochondromata of the right femur with a dominant anterolateral femoral neck osteochondroma causing flexion block. The patient underwent an uncomplicated proximal femoral exostectomy. Six-week postoperative pain, range of movement and daily activity had greatly improved. This case highlights that even in the setting of multiple osteochondromata, excellent impingement relief can be achieved following selective proximal femoral exostectomy.

  14. THE DEVELOPMENT OF IODINE BASED IMPINGER SOLUTIONS FOR THE EFFICIENT CAPTURE OF HG USING DIRECT INJECTION NEBULIZATION - INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY ANALYSIS

    Science.gov (United States)

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hgo) in EPA Method 5 type sampling. An iodine based impinger solutoin proved to be ver...

  15. Experimental investigation of impingement cooling with turbulators or surface enlarging elements

    Energy Technology Data Exchange (ETDEWEB)

    Persson, Johan

    2000-02-01

    For the materials in modern gas turbines to sustain, a considerable amount of cooling is required. In cases where large amounts of heat need to be removed, impingement cooling with its high heat transfer coefficients may be the only alternative. In this work the possibilities of enhancing impingement cooling by introducing surface enlarging - turbulence enhancing elements are examined experimentally. A configuration consisting of a staggered array of 45 impingement jets distributed over 10 rows is used for the purpose. A thermo camera is used to measure the temperature distribution on the target plate, giving an opportunity to separately evaluate the Nusselt number enhancement for different areas. Experiments are conducted for five different area enlarging geometries: triangle, wing, cylinder, dashed rib, and angel, all made from aluminium. Comparison between each area enlarged surface and a flat plate is made, with results presented as Nusselt number enhancement factors. The effect of pumping power required is also investigated in order to maximize the cooling efficiency. Parameters varied are Reynolds number and jet to plate distance. Overall Nusselt number enhancement factors show values of 1 to 1.3, the trend being decreasing with increased jet to plane distance and Reynolds number. When taking into account pumping power the enhancement factors drop to 0.4 to 1.2. The best results are achieved with the rib geometry and when not using a too large value of enlarger height over jet to plate distance (h/z). Row wise evaluation of Nusselt number enhancement shows an increased enhancement with row number and thereby crossflow ratio (Gc/Gj). Typical increases in enhancement of 1 to 1.5 with Gc/Gj from 0 to 0.8 are found. The thermo camera pictures reveal that the enhancement is found in three different areas, on the enlarger base area, the area just downstream the enlarger and in diagonal streaks with increased turbulence caused by the enlargers. Tests using an

  16. Tratamento artroscópico do impacto femoroacetabular Arthroscopic treatment of femoroacetabular impingement

    Directory of Open Access Journals (Sweden)

    Giancarlo C. Polesello

    2009-06-01

    Full Text Available OBJETIVOS: O propósito deste estudo é avaliar os resultados em curto prazo do tratamento artroscópico do impacto femoroacetabular. A hipótese é a de que os resultados do tratamento artroscópico são favoráveis. MÉTODOS: Entre agosto de 2003 e agosto de 2007, 28 quadris foram submetidos ao tratamento do impacto femoroacetabular pela via artroscópica. A idade média dos pacientes foi de 34 anos, com média de seguimento de 27 meses. Quanto à melhora clínica, os pacientes foram avaliados pré e pósoperatoriamente pelo Harris Hip Score (HHS modificado por Byrd. Os pacientes foram avaliados pré e pós-operatoriamente em relação à rotação interna do quadril acometido. Os valores obtidos nos índices acima foram analisados estatisticamente através do método de Wilcoxon para a avaliação de variáveis não paramétricas. RESULTADOS: O Harris Hip Score médio pré-operatório foi de 54,2 e o pós-operatório, de 94,8 (p OBJECTIVE: The purpose of this study is to evaluate the short-term follow-up results of arthroscopic treatment of femoroacetabular impingement. Our hypothesis is that arthroscopic treatment results are favorable. METHODS: Between August 2003 and August 2007, 28 hips had femoroacetabular impingement treated by hip arthroscopy. The mean age was 34 years, with mean follow-up period of 27 months. Clinical results were graded with the modified Harris hip score, which was measured pre-and postoperatively. Patients had also their internal rotation analyzed. These parameters were calculated by using Wilcoxon's t test for analysis of nonparametric paired samples performed. RESULTS: The mean preoperative Harris Hip Score was 54.2, improving to 94.8 postoperatively (p<0,001. The mean increase was 37.5 points. We had 4 good results (15% and 24 excellent results (85%. Preoperatively, the patients had a mean internal rotation of 17º, and, postoperatively, 36º. The average internal rotation increase was 19º (p<0,001. CONCLUSIONS

  17. [Arthroscopic therapy of ankle joint impingement syndrome after operation of ankle joint fracture dislocation].

    Science.gov (United States)

    Feng, Zhibin; Mi, Kun; Wei, Renzhi; Liu, Wu; Wang, Bin

    2011-07-01

    To study the operative procedure and the effectiveness of arthroscopic therapy for ankle joint impingement syndrome after operation of ankle joint fracture dislocation. Between March 2008 and April 2010, 38 patients with ankle joint impingement syndrome after operation of ankle joint fracture dislocation were treated. Among them, there were 28 males and 10 females with an average age of 28 years (range, 18 to 42 years). The time from internal fixation to admission was 12-16 months (mean, 13.8 months). There were pressing pain in anterolateral and anterior ankle. The dorsal extension ranged from -20 to -5 degrees (mean, -10.6 degrees), and the palmar flexion was 30-40 degrees (mean, 35.5 degrees). The total score was 48.32 +/- 9.24 and the pain score was 7.26 +/- 1.22 before operation according to American Orthopaedic Foot and Ankle Society (AOFAS) ankle and hindfoot score system. The X-ray films showed osteophyte formation in anterior tibia and talus; MRI showed cartilage injury in 22 cases. Arthroscopic intervention included removing osteophytes, debriding fabric scars and synovial membrane tissues, and removing osteochondral fragments. Arthroscopic microfracture technique was used in 22 patients with cartilage injury. All incisions healed primarily. Thirty-eight cases were followed up 10-26 months (mean, 16 months). At last follow-up, 26 patients had normal range of motion (ROM); the dorsal extension was 15-25 degrees (mean, 19.6 degrees) and the palmar flexion was 35-45 degrees (mean, 40.7 degrees). Eight patients had mild limited ROM; the dorsal extension was 5-15 degrees (mean, 7.2 degrees) and the palmar flexion was 35-45 degrees (mean, 39.5 degrees). Four patients had mild limited ROM and pain in posterior portion of the ankle after a long walking (3-4 hours); the dorsal extension was 0-5 degrees (mean, 2.6 degrees) and the palmar flexion was 35-40 degrees (mean, 37.5 degrees). The total score was 89.45 +/- 9.55 and the pain score was 1.42 +/- 1.26 after

  18. Knowledge of practising radiographers of the supraspinatus outlet projection for shoulder impingement syndrome in the Eastern Cape, South Africa

    International Nuclear Information System (INIS)

    Williams, R.; Morton, D.G.

    2016-01-01

    Background/Aim: There are many projections in plain film imaging to demonstrate the specific aspects of the anatomy of the shoulder. However, reproducing the required projections can be challenging especially if radiographers are not familiar with the projections and their evaluation criteria. The aim of the study was to explore and describe the knowledge of practising radiographers regarding the supraspinatus outlet projection for shoulder impingement syndrome. Method: A quantitative, exploratory and descriptive design was followed. The population served as the sample and included all the practising radiographers in the public and private hospitals of a metropolitan municipality in the Eastern Cape, South Africa. A total of 84 respondents completed the structured, self-administered questionnaire. Results: The data revealed that in many cases, the majority of radiographers in the study, due to inadequate knowledge levels would not be able to produce an optimal radiographic image of the supraspinatus outlet. The results of the chi-squares indicated statistically significant differences (p < 0.05) between public and private hospitals regarding certain aspects of the scapular Y projection and SOP. Conclusion: It was found that the radiographers in the study had inadequate knowledge of scapular Y projections and SOPs in relation to SIS. Therefore, it is essential to ensure that radiographers are updated on their knowledge of radiographic practice on a continuous basis. - Highlights: • Many radiographers unable to produce an optimal image of the supraspinatus outlet. • Radiographers had poor knowledge of scapular Y and supraspinatus outlet projections. • It is essential that radiographers update their knowledge of radiographic practice.

  19. Experimentally obtained values of electric field of an atmospheric pressure plasma jet impinging on a dielectric surface

    NARCIS (Netherlands)

    Sobota, A.; Guaitella, O.; Garcia-Caurel, E.

    2013-01-01

    We report on experimentally obtained values of the electric field magnitude on a dielectric surface induced by an impinging atmospheric pressure plasma jet. The plasma plume was striking the dielectric surface at an angle of 45¿, at 5mm from the surface measured at the axis of the jet. The results

  20. Flow characteristics and heat transfer performances of a semi-confined impinging array of jets: effect of nozzle geometry

    Energy Technology Data Exchange (ETDEWEB)

    Dano, B.P.E.; Liburdy, J.A. [Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering; Kanokjaruvijit, Koonlaya [Imperial College, London (United Kingdom). Dept. of Mechanical Engineering

    2005-02-01

    The flow and heat transfer characteristics of confined jet array impingement with crossflow is investigated. Discrete impingement pressure measurements are used to obtain the jet orifice discharge flow coefficient. Digital particle image velocimetry (DPIV) and flow visualization are used to determine the flow characteristics. Two thermal boundary conditions at the impinging surface are presented: an isothermal surface, and a uniform heat flux, where thermocouple and thermochromic liquid crystal methods were used, respectively, to determine the local heat transfer coefficient. Two nozzle geometries are studied, circular and cusped ellipse. Based on the interaction with the jet impingement at the surface, the crossflow is shown to influence the heat transfer results. The two thermal boundary conditions differ in overall heat transfer correlation with the jet Reynolds number. Detailed velocity data show that the flow development from the cusped ellipse nozzle affects the wall region flow more than the circular nozzle, as influenced by the crossflow interactions. The overall heat transfer for the uniform heat flux boundary condition is found to increase for the cusped ellipse orifice. (Author)

  1. The importance of bony impingement in restricting flexion after total knee arthroplasty: computer simulation model with clinical correlation.

    Science.gov (United States)

    Mizu-Uchi, Hideki; Colwell, Clifford W; Fukagawa, Shingo; Matsuda, Shuichi; Iwamoto, Yukihide; D'Lima, Darryl D

    2012-10-01

    We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with 125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Computational parametric study of an impinging jet in a cross-flow configuration for electronics cooling applications

    International Nuclear Information System (INIS)

    Larraona, Gorka S.; Rivas, Alejandro; Antón, Raúl; Ramos, Juan Carlos; Pastor, Ignacio; Moshfegh, Bahram

    2013-01-01

    A parametric study based on design of experiments (DoE) techniques was carried out by computational simulation in order to evaluate the effect that design parameters have on heat transfer and pressure loss of an impinging jet in a cross-flow configuration. The main effects of each parameter and the interactions between parameters were analyzed in detail through the Response Surface Methodology (RSM). Additionally, the potential of the impinging jet in a cross-flow configuration was assessed by calculating the optimal values of the parameters and comparing the cooling efficiency of the resulting configuration with the efficiency of the conventional cross-flow configuration. It was found that the degree to which the average heat transfer coefficient is enhanced as the result of adding an impinging jet depends on the height of the cooled component. Specifically, it was found that the higher the component, the more significant the enhancement. -- Highlights: ► Five design parameters of an impinging jet in a cross-flow (IJCF) have been considered. ► Channel and jet velocities are found to be the most influential parameters. ► Significant interactions exist between some of the parameters. ► Larger cooling efficiency is achieved with the IJCF compared to the cross-flow solely. ► The enhancement obtained with the IJCF depends on the height of the component

  3. Aerodynamic and mass transfer characteristicsof an annular bistable impinging jet with a fluidic flip-flop control

    Czech Academy of Sciences Publication Activity Database

    Trávníček, Zdeněk; Peszynsky, K.; Hošek, Jan; Wawrzyniak, S.

    2003-01-01

    Roč. 46, č. 7 (2003), s. 1265-1278 ISSN 0017-9310 R&D Projects: GA AV ČR IBS2076301 Institutional research plan: CEZ:AV0Z2076919 Keywords : impinging jet * visualization * mass transfer Subject RIV: BK - Fluid Dynamics Impact factor: 1.293, year: 2003

  4. Predictions of flow and heat transfer in multiple impinging jets with an elliptic-blending second-moment closure

    NARCIS (Netherlands)

    Thielen, L.; Hanjalić, K.; Jonker, H.; Manceau, R.

    2005-01-01

    We present numerical computations of flow and heat transfer in multiple jets impinging normally on a flat heated surface, obtained with a new second-moment turbulence closure combined with an elliptic blending model of non-viscous wall blocking effect. This model provides the mean velocity and

  5. Deposition of micron liquid droplets on wall in impinging turbulent air jet

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Tianshu; Nink, Jacob; Merati, Parviz [Western Michigan University, Department of Mechanical and Aeronautical Engineering, Kalamazoo, MI (United States); Tian, Tian; Li, Yong [Massachusetts Institute of Technology, Sloan Automotive Laboratory, Cambridge, MA (United States); Shieh, Tom [Toyota Technical Center, Toyota Motor Engineering and Manufacturing North America, Inc, Ann Arbor, MI (United States)

    2010-06-15

    The fluid mechanics of the deposition of micron liquid (olive oil) droplets on a glass wall in an impinging turbulent air jet is studied experimentally. The spatial patterns of droplets deposited on a wall are measured by using luminescent oil visualization technique, and the statistical data of deposited droplets are obtained through microscopic imagery. Two distinct rings of droplets deposited on a wall are found, and the mechanisms of the formation of the inner and outer rings are investigated based on global diagnostics of velocity and skin friction fields. In particular, the intriguing effects of turbulence, including large-scale coherent vortices and small-scale random turbulence, on micron droplet deposition on a wall and coalescence in the air are explored. (orig.)

  6. [Posterosuperior impingement of the shoulder in the athlete: results of arthroscopic debridement in 75 patients].

    Science.gov (United States)

    Riand, N; Boulahia, A; Walch, G

    2002-02-01

    The painful shoulder is a well-recognized clinical entity in throwers although the pathogenic mechanisms involved are still debated. In 1991 Walch then Jobe developed the concept of posterosuperior impingement to explain lesions observed arthroscopically. This impingement between the deep aspect of the supraspinatus tendon and the glenoid occurs during loaded arm movements. The purpose of this work was to study the different types of lesions observed arthroscopically and to analyse outcome after arthroscopic debridement. Our series included 75 thrower athletes who had shoulder pain for loaded arm movements. Pain was situated in the dominant shoulder in all cases. Clinically, the Jobe manipulation provoked pain in 52 patents, expression of a supraspinous disorder. After failure of conservative treatment, the patients underwent arthroscopy for assessment and debridement. At the time of arthroscopy, the patients had suffered pain for two years (mean 22.3 months). All 75 patients were seen for clinical and radiological assessment at least two years after arthroscopy. Among the 75 arthroscopies, there were 67 (89%) partial tears involving the deep aspect of the cuff, associated in 90% of the cases with a labral lesion. Tears involved the supraspinatus in 40 cases, the supraspinatus and the infraspinatus in 24 and the infraspinatus alone in three. Eight patients were free of tendon lesions at arthroscopy. There were no full thickness tears. The labrum had a meniscal (45%) or non-meniscal aspect (55%) and appeared normal (18%), fringed (38%) or fissured (52%). The very large majority of the labral fissures were found behind the biceps insertion. Fissures of the labrum were found in front of the biceps insertion in only three cases (slap lesion). Arthroscopy demonstrated glenoid damage (soft cartilage, fissure, abrasion, wear). The humeral head also exhibited lesions of the cartilage facing the insertion of the infraspinatus. At last follow-up (minimum > 2 years), eight

  7. Femoro-acetabular impingement and hip pain with conventionally normal x-rays.

    LENUS (Irish Health Repository)

    Baker, J F

    2010-06-01

    There has in recent years been a fundamental change in the understanding of hip pain in the young adult and hip pain without plain radiographic findings of arthritis. Pain in these groups has long represented a diagnostic and therapeutic challenge. With new appreciation of hip biomechanics, pathological processes and the arrival of modern imaging modalities we now have a greater understanding of non-arthritic hip pathology. One of the commonest yet least well recognized \\'new\\' diagnoses around the hip is femoro-acetabular impingement (FAI). FAI is a developmental condition of the hip joint that is associated with abnormal anatomical configuration and thus joint mechanics on either the femoral or acetabular sides or both. It is hypothesized to have a variety of precipitants and may ultimately lead to labral and chondral injury and what has previously been referred to as \\'primary\\' or \\'idiopathic\\' hip osteoarthritis.

  8. Jet Impingement Heat Transfer at High Reynolds Numbers and Large Density Variations

    DEFF Research Database (Denmark)

    Jensen, Michael Vincent; Walther, Jens Honore

    2010-01-01

    Jet impingement heat transfer from a round gas jet to a flat wall has been investigated numerically in a configuration with H/D=2, where H is the distance from the jet inlet to the wall and D is the jet diameter. The jet Reynolds number was 361000 and the density ratio across the wall boundary...... layer was 3.3 due to a substantial temperature difference of 1600K between jet and wall. Results are presented which indicate very high heat flux levels and it is demonstrated that the jet inlet turbulence intensity significantly influences the heat transfer results, especially in the stagnation region....... The results also show a noticeable difference in the heat transfer predictions when applying different turbulence models. Furthermore calculations were performed to study the effect of applying temperature dependent thermophysical properties versus constant properties and the effect of calculating the gas...

  9. Modeling of Heat Transfer and Ablation of Refractory Material Due to Rocket Plume Impingement

    Science.gov (United States)

    Harris, Michael F.; Vu, Bruce T.

    2012-01-01

    CR Tech's Thermal Desktop-SINDA/FLUINT software was used in the thermal analysis of a flame deflector design for Launch Complex 39B at Kennedy Space Center, Florida. The analysis of the flame deflector takes into account heat transfer due to plume impingement from expected vehicles to be launched at KSC. The heat flux from the plume was computed using computational fluid dynamics provided by Ames Research Center in Moffet Field, California. The results from the CFD solutions were mapped onto a 3-D Thermal Desktop model of the flame deflector using the boundary condition mapping capabilities in Thermal Desktop. The ablation subroutine in SINDA/FLUINT was then used to model the ablation of the refractory material.

  10. Numerical analysis of jet impingement heat transfer at high jet Reynolds number and large temperature difference

    DEFF Research Database (Denmark)

    Jensen, Michael Vincent; Walther, Jens Honore

    2013-01-01

    was investigated at a jet Reynolds number of 1.66 × 105 and a temperature difference between jet inlet and wall of 1600 K. The focus was on the convective heat transfer contribution as thermal radiation was not included in the investigation. A considerable influence of the turbulence intensity at the jet inlet...... to about 100% were observed. Furthermore, the variation in stagnation point heat transfer was examined for jet Reynolds numbers in the range from 1.10 × 105 to 6.64 × 105. Based on the investigations, a correlation is suggested between the stagnation point Nusselt number, the jet Reynolds number......, and the turbulence intensity at the jet inlet for impinging jet flows at high jet Reynolds numbers. Copyright © 2013 Taylor and Francis Group, LLC....

  11. Study on Design Change of a Pipe Affected by Liquid Droplet Impingement Erosion

    International Nuclear Information System (INIS)

    Hwang, Kyeong Mo; Lee, Chan Gyu; Bhang, Keug Jin; Yim, Young Sig

    2011-01-01

    Liquid droplet impingement erosion (LDIE) is caused by the impact of high-velocity droplets entrained in steam or air on metal. The degradation caused by the LDIE has been experienced in steam turbine internals and high-velocity airplane components (particularly canopies). Recently, LDIE has also been observed in the pipelines of nuclear plants. LDIE among the pipelines occurs when two-phase steam experiences a high pressure drop (e.g., across an orifice in a line to the condenser). In 2011, a nuclear power plant in Korea experienced a steam leak caused by LDIE in a pipe through which a two-phase fluid was flowing. This paper describes a study on the design change of a pipe affected by LDIE in order to mitigate the damage. The design change has been reviewed in terms of fluid dynamics by using the FLUENT code

  12. The jet impingement cell: A valuable device for investigating CO{sub 2} corrosion

    Energy Technology Data Exchange (ETDEWEB)

    Kinsella, Brian; John, Douglas; Bailey, Stuart; De Marco, Roland [Western Australian Corrosion Research Group, School of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA, 6845 (Australia)

    2004-07-01

    The jet impingement cell (JIC) is a valuable technique for the investigation of carbon dioxide corrosion of steel and its inhibition under high flow conditions or high wall shear stress. Despite the use of the JIC in corrosion testing laboratories not a great deal has been published on the design and calibration of these cells. In the evaluation of corrosion inhibitors, the type of corrosion and relative performance of the inhibitors depends on the metallurgy of the steel used to manufacture electrodes and measure the corrosion rate. This paper covers aspects of cell design and the determination of mass transfer and wall shear stress at electrodes used in the cell. The performance of different generic type corrosion inhibitors and their affect on the type of corrosion (i.e, uniform, pitting and crevice corrosion) is shown and discussed. (authors)

  13. Evaluation of free jet and jet impingement tests with hot water and steam

    International Nuclear Information System (INIS)

    Marklund, J.E.

    1985-01-01

    Large scale free jet and jet impingement tests with hot water and steam were performed at the Marviken test facility, Sweden in the JIT project 1980-1981. Similar tests, but with smaller scale equipment, were performed in Canada, Italy and Japan. Results from these tests were made available to the JIT project as in-kind contributions. The present report summarizes an evaluation effort over these large and small scale tests, as well as some additional small scale tests. A preliminary assessment of some computer code models and other theoretical models or correlations is also included. The work was financially supported by the Swedish Nuclear Power Inspectorate, and in phase 1 also by the Electric Power Research Institute (EPRI), USA. Part 1 of the report contains text and tables, while the figures are contained in a separate cover, Part 2. (author)

  14. Fish species composition, density-distribution patterns, and impingement during upwelling

    International Nuclear Information System (INIS)

    Spigarelli, S.A.; Sharma, R.K.

    1975-01-01

    The effects of cooling system intakes and discharges on Lake Michigan fishes are highly dependent on inshore species composition and spatial distribution which, in turn, are affected by natural hydrological conditions. Significant (5 to 10 C) short-term decreases in water temperature (due to upwelling) could cause cold shock in fish equilibrated to either ambient or plume temperatures; substantial changes in distribution due to avoidance or attraction responses; and resultant changes in susceptibility to impingement. The objectives of this study are to characterize the changes in fish species composition, density, and thermal distribution as a result of natural upwellings, and to relate these factors to intake and discharge effects. Day and night sampling was conducted in ambient (reference) and thermal plume waters near the Zion Nuclear Plant on four occasions between 17 July and 11 September 1975. Density-distribution patterns and species composition of fish were determined by means of gill nets, bottom trawls, seines, and a sonic fish locater

  15. Clinical trials in orthopaedics and the future direction of clinical investigations for femoroacetabular impingement

    DEFF Research Database (Denmark)

    Clohisy, John C; Kim, Young-Jo; Lurie, Jon

    2013-01-01

    to be further defined. To date, clinical research reports have included primarily surgical case series. Future clinical investigations are needed to establish improved clinical evidence to guide patient care. Most urgent is the need to better understand the potential role of standardized nonsurgical treatment......Femoroacetabular impingement (FAI) represents a heterogeneous group of disorders that affect a diverse patient population. The natural history of the disease, the role of nonsurgical management, the indications for surgery, optimal surgical techniques, and the predictors of treatment outcomes need...... options for FAI and to define the predictors of surgical and nonsurgical outcomes. Future randomized controlled trials and large observational cohort studies targeted at these clinical research deficiencies will strengthen the evidence and improve informed decision making regarding the management...

  16. Core Muscle Injury/Sports Hernia/Athletic Pubalgia, and Femoroacetabular Impingement.

    Science.gov (United States)

    Ross, James R; Stone, Rebecca M; Larson, Christopher M

    2015-12-01

    Core muscle injury/sports hernia/athletic pubalgia is an increasingly recognized source of pain, disability, and time lost from athletics. Groin pain among athletes, however, may be secondary to various etiologies. A thorough history and comprehensive physical examination, coupled with appropriate diagnostic imaging, may improve the diagnostic accuracy for patients who present with core muscular injuries. Outcomes of nonoperative management have not been well delineated, and multiple operative procedures have been discussed with varying return-to-athletic activity rates. In this review, we outline the clinical entity and treatment of core muscle injury and athletic pubalgia. In addition, we describe the relationship between athletic pubalgia and femoroacetabular impingement along with recent studies that have investigated the treatment of these related disorders.

  17. Numerical Study of Impingement Location of Liquid Jet Poured from a Tilting Ladle with Lip Spout

    Science.gov (United States)

    Castilla, R.; Gamez-Montero, P. J.; Raush, G.; Khamashta, M.; Codina, E.

    2017-04-01

    A new approach for simulating liquid poured from a tilting lip spout is presented, using neither a dynamic mesh nor the moving solid solution method. In this case only the tilting ladle is moving, so we propose to rotate the gravitational acceleration at an angular velocity prescribed by a geometrical and dynamical calculation to keep the poured flow rate constant. This angular velocity is applied to modify the orientation of the gravity vector in computational fluid dynamics (CFD) simulations using the OpenFOAM® toolbox. Also, fictitious forces are considered. The modified solver is used to calculate the impingement location for six spout geometries and compare the jet dispersion there. This method could offer an inexpensive tool to calculate optimal spout geometries to reduce sprue size in the metal casting industry.

  18. Boiling hysteresis of impinging circular submerged jets with highly wetting liquids

    International Nuclear Information System (INIS)

    Zhou, D.W.; Ma, C.F.; Yu, J.

    2004-01-01

    An experimental study was carried out to characterize the boiling hysteresis of impinging circular submerged jets with highly wetting liquids. The effects of noncondensable gases and surface aging on boiling curves were considered. The present study focused on the effects of jet parameters (jet exit velocity, radial distance from the stagnation point and nozzle diameter) and fluid subcooling on incipient boiling superheat and superheat excursion, as well as the physical mechanism of boiling hysteresis. Results show that the incipient boiling superheat decreases only with fluid subcooling regardless of jet parameters, and that the superheat excursion increases with nozzle diameter and radial distance from the stagnation point and decreasing jet exit velocity and fluid subcooling. Boiling hysteresis occurs due to deactivation of vapor embryos within larger cavities. Three anomalous phenomena at boiling inception are recorded and discussed in terms of irregular activation of vapor embryos

  19. Study on Design Change of a Pipe Affected by Liquid Droplet Impingement Erosion

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Kyeong Mo; Lee, Chan Gyu [KEPCO Engineering and Construction Co., Daejeon (Korea, Republic of); Bhang, Keug Jin; Yim, Young Sig [Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2011-10-15

    Liquid droplet impingement erosion (LDIE) is caused by the impact of high-velocity droplets entrained in steam or air on metal. The degradation caused by the LDIE has been experienced in steam turbine internals and high-velocity airplane components (particularly canopies). Recently, LDIE has also been observed in the pipelines of nuclear plants. LDIE among the pipelines occurs when two-phase steam experiences a high pressure drop (e.g., across an orifice in a line to the condenser). In 2011, a nuclear power plant in Korea experienced a steam leak caused by LDIE in a pipe through which a two-phase fluid was flowing. This paper describes a study on the design change of a pipe affected by LDIE in order to mitigate the damage. The design change has been reviewed in terms of fluid dynamics by using the FLUENT code.

  20. Conceptual thermal-mechanical design of the TFTR first wall armor against neutral beam impingement

    International Nuclear Information System (INIS)

    Chi, J.W.H.; Flaherty, R.

    1976-01-01

    The Tokamak Fusion Test Reactor (TFTR) is designed to operate in a pulsed mode with relatively low duty cycles. Each pulse consists of a short plasma heat-up period, a reaction period, followed by a relatively long cooldown period. Plasma heating is accomplished by ohmic heating by a current induced change in the magnetically linked ohmic heating coils, followed by neutral beam injection for further preheat and the initiation of fusion reactions. During normal operation, the bulk of the neutral beam energy will be absorbed by the plasma, while the remainder will impinge on the vacuum vessel wall. The amount of thermal energy deposited on an unprotected wall is expected to be excessive, limiting the frequency of pulses and requiring frequent wall replacement. A faulted condition would cause penetration of an unprotected wall. As a consequence, a wall armoring (or liner) concept was developed to protect the vacuum vessel wall and to permit ease of liner replacement

  1. CPV cells cooling system based on submerged jet impingement: CFD modeling and experimental validation

    Science.gov (United States)

    Montorfano, Davide; Gaetano, Antonio; Barbato, Maurizio C.; Ambrosetti, Gianluca; Pedretti, Andrea

    2014-09-01

    Concentrating photovoltaic (CPV) cells offer higher efficiencies with regard to the PV ones and allow to strongly reduce the overall solar cell area. However, to operate correctly and exploit their advantages, their temperature has to be kept low and as uniform as possible and the cooling circuit pressure drops need to be limited. In this work an impingement water jet cooling system specifically designed for an industrial HCPV receiver is studied. Through the literature and by means of accurate computational fluid dynamics (CFD) simulations, the nozzle to plate distance, the number of jets and the nozzle pitch, i.e. the distance between adjacent jets, were optimized. Afterwards, extensive experimental tests were performed to validate pressure drops and cooling power simulation results.

  2. Wastewater treatment using photo-impinging streams cyclone reactor: Computational fluid dynamics and kinetics modeling

    Energy Technology Data Exchange (ETDEWEB)

    Royaee, Sayed Javid; Shafeghat, Amin [Research Institute of Petroleum Industry, Tehran (Iran, Islamic Republic of); Sohrabi, Morteza [Amirkabir University of Technology, Tehran (Iran, Islamic Republic of)

    2014-02-15

    A photo impinging streams cyclone reactor has been used as a novel apparatus in photocatalytic degradation of organic compounds using titanium dioxide nanoparticles in wastewater. The operating parameters, including catalyst loading, pH, initial phenol concentration and light intensity have been optimized to increase the efficiency of the photocatalytic degradation process within this photoreactor. The results have demonstrated a higher efficiency and an increased performance capability of the present reactor in comparison with the conventional processes. In the next step, residence time distribution (RTD) of the slurry phase within the reactor was measured using the impulse tracer method. A CFD-based model for predicting the RTD was also developed which compared well with the experimental results. The RTD data was finally applied in conjunction with the phenol degradation kinetic model to predict the apparent rate coefficient for such a reaction.

  3. Simulation of attenuation of thermal fluctuations near a plate impinged by jets

    International Nuclear Information System (INIS)

    Simoneau, J.P.

    2001-01-01

    In nuclear reactors, and especially in liquid sodium cooled ones, the combination of temperature differences inside cooling fluid, turbulent flows and high heat transfer coefficients is a potential source of the thermal striping process. Such a phenomenon has been studied for several years by using Large Eddy Simulation models. The present paper focuses on the attenuation of the thermal fluctuations in the boundary layer. The knowledge of this amplitude reduction is of prime importance for subsequent mechanical analyses. A Large Eddy Simulation model is implemented in the Star-cd code, including discretization of the viscous sublayer. The numerical simulation of two parallel jets impinging a flat plate in water is then performed and positively compared to corresponding experimental results. (author)

  4. Numerical study of turbulent heat transfer from confined impinging jets using a pseudo-compressibility method

    Energy Technology Data Exchange (ETDEWEB)

    Rahman, M.; Rautaheimo, P.; Siikonen, T.

    1997-12-31

    A numerical investigation is carried out to predict the turbulent fluid flow and heat transfer characteristics of two-dimensional single and three impinging slot jets. Two low-Reynolds-number {kappa}-{epsilon} models, namely the classical model of Chien and the explicit algebraic stress model of Gatski and Speziale, are considered in the simulation. A cell-centered finite-volume scheme combined with an artificial compressibility approach is employed to solve the flow equations, using a diagonally dominant alternating direction implicit (DDADI) time integration method. A fully upwinded second order spatial differencing is adopted to approximate the convective terms. Roe`s damping term is used to calculate the flux on the cell face. A multigrid method is utilized for the acceleration of convergence. On average, the heat transfer coefficients predicted by both models show good agreement with the experimental results. (orig.) 17 refs.

  5. The Horsens-Aarhus Femoro Acetabular Impingement (HAFAI) cohort: outcome of arthroscopic treatment for femoroacetabular impingement. Protocol for a prospective cohort study.

    Science.gov (United States)

    Kierkegaard, Signe; Lund, Bent; Dalgas, Ulrik; Sørensen, Henrik; Søballe, Kjeld; Mechlenburg, Inger

    2015-09-07

    During the past decade, it has become increasingly more common to offer hip arthroscopic surgery when treating people with femoroacetabular impingement (FAI). Nevertheless, the latest reviews conclude that it still remains to be properly investigated how surgery affects the patients. Specifically, detailed information on the functional, muscular and mechanical impact of surgery in larger groups is lacking. Furthermore, the long-term outcome of the surgery is still to be investigated. In this prospective cohort study, a total of 60 patients with FAI scheduled for arthroscopic surgery will be followed and tested preoperatively, and again after 3, 6, 9 and 12 months. Assessment includes isokinetic dynamometry evaluating hip flexion and extension; evaluation of functional capacity in a three-dimensional motion laboratory; pain assessment; self-reported function, quality of life, expectation and satisfaction with the surgery; recording of previous and present sporting activities and accelerometry. In addition, data on surgical procedure, rehabilitation progress, adverse events and failure will be recorded. Patients will be compared with an age-matched and gender-matched reference group of 30 persons with no hip, knee, ankle or back problems. Long-term follow-up of this cohort may evaluate possible reoperations and development of hip osteoarthritis. Furthermore, analysis on how subgroups respond to the treatment could be performed together with identification of possible "non-responders". The study is approved by the Central Denmark Region Committee on Biomedical Research Ethics (Journal No 1-10-72-239-14). The results from this study will be presented at national and international congresses and published in peer-reviewed journals. NCT02306525. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  6. Crust behavior and erosion rate prediction of EPR sacrificial material impinged by core melt jet

    Energy Technology Data Exchange (ETDEWEB)

    Li, Gen; Liu, Ming, E-mail: ming.liu@mail.xjtu.edu.cn; Wang, Jinshi; Chong, Daotong; Yan, Junjie

    2017-04-01

    Highlights: • A numerical code was developed to analyze melt jet-concrete interaction in the frame of MPS method. • Crust and ablated concrete layer at UO{sub 2}-ZrO{sub 2} melt and concrete interface periodically developed and collapsed. • Concrete surface temperature fluctuated around a low temperature and ablation temperature. • Concrete erosion by Fe-Zr melt jet was significantly faster than that by UO{sub 2}-ZrO{sub 2} melt jet. - Abstract: Sacrificial material is a special ferro-siliceous concrete, designed in the ex-vessel core melt stabilization system of European Pressurized water Reactor (EPR). Given a localized break of RPV lower head, the melt directly impinges onto the dry concrete in form of compact jet. The concrete erosion behavior influences the failure of melt plug, and further affects melt spreading. In this study, a numerical code was developed in the frame of Moving Particle Semi-implicit (MPS) method, to analyze the crust behavior and erosion rate of sacrificial concrete, impinged by prototypic melt jet. In validation of numerical modeling, the time-dependent erosion depth and erosion configuration matched well with the experimental data. Sensitivity study of sacrificial concrete erosion indicates that the crust and ablated concrete layer presented at UO{sub 2}-ZrO{sub 2} melt and concrete interface, whereas no crust could be found in the interaction of Fe-Zr melt with concrete. The crust went through stabilization-fracture-reformation periodic process, accompanied with accumulating and collapsing of molten concrete layer. The concrete surface temperature fluctuated around a low temperature and ablation temperature. It increased as the concrete surface layer was heated to melting, and dropped down when the cold concrete was revealed. The erosion progression was fast in the conditions of small jet diameter and large concrete inclination angle, and it was significantly faster in the erosion by metallic melt jet than by oxidic melt jet.

  7. Liquid jet impingement cooling with diamond substrates for extremely high heat flux applications

    International Nuclear Information System (INIS)

    Lienhard V, J.H.

    1993-01-01

    The combination of impinging jets and diamond substrates may provide an effective solution to a class of extremely high heat flux problems in which very localized heat loads must be removed. Some potential applications include the cooling of high-heat-load components in synchrotron x-ray, fusion, and semiconductor laser systems. Impinging liquid jets are a very effective vehicle for removing high heat fluxes. The liquid supply arrangement is relatively simple, and low thermal resistances can be routinely achieved. A jet's cooling ability is a strong function of the size of the cooled area relative to the jet diameter. For relatively large area targets, the critical heat fluxes can approach 20 W/mm 2 . In this situation, burnout usually originates at the outer edge of the cooled region as increasing heat flux inhibits the liquid supply. Limitations from liquid supply are minimized when heating is restricted to the jet stagnation zone. The high stagnation pressure and high velocity gradients appear to suppress critical flux phenomena, and fluxes of up to 400 W/mm 2 have been reached without evidence of burnout. Instead, the restrictions on heat flux are closely related to properties of the cooled target. Target properties become an issue owing to the large temperatures and large temperature gradients that accompany heat fluxes over 100 W/mm 2 . These conditions necessitate a target with both high thermal conductivity to prevent excessive temperatures and good mechanical properties to prevent mechanical failures. Recent developments in synthetic diamond technology present a possible solution to some of the solid-side constraints on heat flux. Polycrystalline diamond foils can now be produced by chemical vapor deposition in reasonable quantity and at reasonable cost. Synthetic single crystal diamonds as large as 1 cm 2 are also available

  8. Coordination of deep hip muscle activity is altered in symptomatic femoroacetabular impingement.

    Science.gov (United States)

    Diamond, Laura E; Van den Hoorn, Wolbert; Bennell, Kim L; Wrigley, Tim V; Hinman, Rana S; O'Donnell, John; Hodges, Paul W

    2017-07-01

    Diagnosis of femoroacetabular impingement (FAI) is increasing, yet the associated physical impairments remain poorly defined. This morphological hip condition can cause joint pain, stiffness, impaired function, and eventually hip osteoarthritis. This exploratory study compared coordination of deep hip muscles between people with and without symptomatic FAI using analysis of muscle synergies (i.e., patterns of activity of groups of muscles activated in synchrony) during gait. Fifteen individuals (11 males) with symptomatic FAI (clinical examination and imaging) and 14 age- and sex-comparable controls without morphological FAI underwent testing. Intramuscular fine-wire and surface electrodes recorded electromyographic activity of selected deep and superficial hip muscles. A non-negative matrix factorization algorithm extracted three synergies which were compared between groups. Information regarding which muscles were activated together in the FAI group (FAI group synergy vector) was used to reconstruct individual electromyography patterns and compare groups. Variance accounted for (VAF) by three synergies was less for the control (94.8 [1.4]%) than FAI (96.0 [1.0]%) group (p = 0.03). VAF of obturator internus was significantly higher in the FAI group (p = 0.02). VAF of the reconstructed individual electromyography patterns with the FAI or control group vector were significantly higher for the FAI group (p hip muscles in the synergy related to hip joint control during early swing differed between groups. This phase involves movement towards the impingement position, which has relevance for the interpretation of synergy differences and potential clinical importance. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1494-1504, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  9. Active control of supersonic impingement tones using steady and pulsed microjets

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.J.; Anaswamy, A.M. [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge (United States); Lou, H. [Department of Mechanical Engineering, FAMU - FSU, College of Engineering, Tallahassee, FL (United States); Alvi, F.S.

    2006-12-15

    In recent years, it has been demonstrated that direct microjet injection into the shear layer of the main jet disrupts the feedback loop inherent in high speed impinging jet flows, thereby significantly reducing the adverse effects. The amount of noise reduced by microjet actuation is known to be dependent on nozzle operating conditions. In this paper, two active control strategies using microjets are suggested to maintain a uniform, reliable, and optimal reduction of these tones over the entire range of operating conditions. In the first method, a quasi-closed loop control strategy is proposed using steady microjet injection and the proper orthogonal decomposition (POD) algorithm. The most energetic spatial mode of the unsteady pressure along the nozzle diameter is captured using the POD, which in turn is used to determine the distribution of microjet intensity along the nozzle exit. Preliminary experimental results from a STOVL supersonic jet facility at Mach 1.5 show that the quasi-closed loop control strategy, in some cases, provides an additional 8-10 dB reduction compared to axisymmetric injection at the desired operating conditions. The second method consists of a pulsed microjet injection, motivated by the need to further improve the noise suppression. It was observed that the pulsed microjet was able to bring about the same noise reduction as steady injection using approximately 40% of the corresponding mass flow rate of the steady microjet case. Moreover, as the duty cycle increased, the performance of pulsed injection was further enhanced and was observed to completely eliminate the impinging tones at all operating conditions. (orig.)

  10. Scapular Notching on Kinematic Simulated Range of Motion After Reverse Shoulder Arthroplasty Is Not the Result of Impingement in Adduction

    Science.gov (United States)

    Lädermann, Alexandre; Gueorguiev, Boyko; Charbonnier, Caecilia; Stimec, Bojan V.; Fasel, Jean H.D.; Zderic, Ivan; Hagen, Jennifer; Walch, Gilles

    2015-01-01

    Abstract Impingement after reverse shoulder arthroplasty (RSA) is believed to occur from repetitive contact in adduction between the humeral component and the inferior scapular pillar. The primary purpose of this biomechanical study was to confirm the presence of different types of impingement and to examine which daily-life movements are responsible for them. A secondary aim was to provide recommendations on the type of components that would best minimize notching and loss of range of motion (ROM). The study included 12 fresh frozen shoulder specimens; each had a computed tomography (CT) image of the entire scapula and humerus in order to acquire topological information of the bones before RSA implantation. Cyclic tests were run postimplantation with 3 shoulders in each modalities. To quantify bone loss due to impingement, 3-dimensional anatomical models of the scapula were reconstructed from the CT scans and compared to their intact states. We found 8 bony impingements in 7 specimens: 2 at the lateral acromion, 1 at the inferior acromion, 4 scapular notching, and 1 with the glenoid resulting to wear at the 3:00 to 6:00 clock-face position. Impingements occurred in all kinds of tested motions, except for the internal/external rotation at 90° of abduction. The 3 specimens tested in abduction/adduction presented bone loss on the acromion side only. Scapular notching was noted in flexion/extension and in internal/external rotation at 0° of abduction. The humeral polyethylene liner was worn in 2 specimens—1 at the 6:00 to 8:00 clock-face position during internal/external rotation at 0° of abduction and 1 at the 4:00 clock-face position during flexion/extension. The present study revealed that 2 types of impingement interactions coexist and correspond to a frank abutment or lead to a scapular notching (friction-type impingement). Scapular notching seems to be caused by more movements or combination of movements than previously considered, and in particular by

  11. [Efficacies of arthroscopic debridement and olecranon fossa plasty in the treatment of osteoarthritis and posterior elbow impingement].

    Science.gov (United States)

    Liu, Yu-jie; Wang, Jun-liang; Li, Hai-feng; Qi, Wei; Wang, Ning

    2012-07-17

    To evaluate the efficacies of arthroscopic debridement and removal of osteophyma for olecroanon and olecranon fossa plasty for posterior impingement of elbow joint. Between 1999 and 2008, a total of 21 cases were diagnosed with osteoarthritis and posterior elbow impingement. There were 15 males and 6 females. And there were 16 right and 15 left cases. They included volleyball players (n = 7), tennis players (n = 7), golf enthusiasts (n = 4) and fencers (n = 3). The average duration of onset-operation was 3.5 years (range: 2.5 - 8). Arthroscopic exploration revealed synovial hyperplasia hypertrophy, cartilage degeneration and olecranon fossa hyperplasia with deformed olecranon fossa. Debridement and plasty were performed. Loose bodies were removed from elbow joint in 6 patients. Partial resection of posterior olecranon tip was performed and osteophytes or fibrous tissue removed in this area. Dynamic observation showed no posterior elbow impingement. Postoperative follow-up was conducted in 19 cases and 2 cases became lost to follow-up. The average follow-up period was 25.3 months (range: 18 - 42). All patients were evaluated preoperatively and postoperatively with the Hospital for Special Surgery Elbow Assessment Scale. The outcomes were excellent (n = 12), good (n = 7) and fair (n = 2). Postoperative patients elbow swelling and pain relieve, sports and life function returns to normal, elbow flexion and rotating mobility obviously improved. With the elbow radiological films to measure the range of motion, the average range of motion was 90.5° preoperatively and improved to 130° postoperatively. There was significant improvement in all cases. Posterior elbow impingement is caused by hyperextension trauma and elbow overuse during specific sporting activities. Arthroscopic debridement and olecroanon or olecranon fossa plasty demonstrates excellent results for posterior impingement of elbow joint.

  12. Two or more impingement and/or instability deformities are often present in patients with hip pain.

    Science.gov (United States)

    Tibor, Lisa M; Liebert, Gunnar; Sutter, Reto; Impellizzeri, Franco M; Leunig, Michael

    2013-12-01

    Damage to the hip can occur due to impingement or instability caused by anatomic factors such as femoral and acetabular version, neck-shaft angle, alpha angle, and lateral center-edge angle (CEA). The associations between these anatomic factors and how often they occur in a painful hip are unclear but if unaddressed might explain failed hip preservation surgery. We determined (1) the influence of sex on the expression of impingement-related or instability-related factors, (2) the associations among these factors, and (3) how often both impingement and/or instability factors occur in the same hip. We retrospectively reviewed a cohort of 170 hips (145 patients) undergoing MR arthrography of the hip for any reason. We excluded 58 hips with high-grade dysplasia, Perthes' sequelae, previous surgery, or incomplete radiographic information, leaving 112 hips (96 patients). We measured femoral version and alpha angles on MR arthrograms. Acetabular anteversion, lateral CEA, and neck-shaft angle were measured on pelvic radiographs. We observed a correlation between sex and alpha angle. Weak or no correlations were observed between the other five parameters. In 66% of hips, two or more (of five) impingement parameters, and in 51% of hips, two or more (of five) instability parameters were found. Patients with hip pain frequently have several anatomic factors potentially contributing to chondrolabral damage. To address pathologic hip loading due to impingement and/or instability, all of the anatomic influences should be known. As we found no associations between anatomic factors, we recommend an individualized assessment of each painful hip.

  13. Heat/mass transfer on effusion plate with circular pin fins for impingement/effusion cooling system with initial crossflow

    International Nuclear Information System (INIS)

    Hong, Sung Kook; Rhee, Dong Ho; Cho, Hyung Hee

    2005-01-01

    Impingement/effusion cooling technique is used for combustor liner or turbine parts cooling in gas turbine engine. In the impingement/effusion cooling system, the crossflow generated in the cooling channel induces an adverse effect on the cooling performance, which consequently affects the durability of the cooling system. In the present study, to reduce the adverse effect of the crossflow and improve the cooling performance, circular pin fins are installed in impingement/effusion cooling system and the heat transfer characteristics are investigated. The pin fins are installed between two perforated plates and the crossflow passes between these two plates. A blowing ratio is changed from 0.5 to 1.5 for the fixed jet Reynolds number of 10,000 and five circular pin fin arrangements are considered in this study. The local heat/mass transfer coefficients on the effusion plate are measured using a naphthalene sublimation method. The results show that local distributions of heat/mass transfer coefficient are changed due to the installation of pin fins. Due to the generation of vortex and wake by the pin fin, locally low heat/mass transfer regions are reduced. Moreover, the pin fin prevents the wall jet from being swept away, resulting in the increase of heat/mass transfer. When the pin fin is installed in front of the impinging jet, the blockage effect on the crossflow enhances the heat/mass transfer. However, the pin fin installed just behind the impinging jet blocks up the wall jet, decreasing the heat/mass transfer. As the blowing ratio increases, the pin fins lead to the higher Sh value compared to the case without pin fins, inducing 16%∼22% enhancement of overall Sh value at high blowing ratio of M=1.5

  14. Development of iodine based impinger solutions for the efficient capture of Hg{sup 0} using direct injection nebulization-inductively coupled plasma mass spectrometry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Hedrick, E.; Lee, T.G.; Biswas, P.; Zhuang, Y. [US Environmental Protection Agency, Cincinnati, OH (USA). National Exposure Research Laboratory

    2001-09-15

    Inductively coupled plasma mass spectrometry (ICP/MS) with direct injection nebulization (DIN) was used to evaluate novel impinger solution compositions capable of capturing elemental mercury (Hg{sup 0}) in EPA Method 5 type sampling. An iodine based impinger solution proved to be very efficient for Hg{sup 0} capture and was amenable to direct analysis by DIN-ICP/MS. Hg{sup 0} capture efficiency using aqueous iodine (I{sub 3}{sup -}) was comparable to Hg{sup 0} capture using acidified potassium permanganate impinger solutions which were analyzed by cold vapor atomic absorption spectrometry (CVAAS) with greater than 98% capture of Hg{sup 0} in the oxidizing impinger. Using DIN-ICP/MS, it was demonstrated for the first time that iodine can be generated just prior to impinger sampling for efficiently oxidizing Hg{sup 0} and retailing it in solution as HgI{sub 4}{sup 2-}. Due to the increased interest in Hg speciation from combustion sources and the potential for using DIN-ICP/MS for multiple metals analyses, an impinger sampling train for gaseous Hg speciation and multiple metals analyses using DIN-ICP/MS analyses is presented. The unique feature of such a sampling train is that each impinger solution in the series is amenable to direct analysis by DIN-ICP/MS. A bituminous coal was combusted in a bench scale coal system, and gaseous Hg species (oxidized and elemental) were determined using the proposed impinger train. The DIN-ICP/Ms instrumental detection limit was 0.003 ppb, and MDLs ranged from 0.007 to 0.116 {mu}g/L (ppb) in a variety of impinger solutions used for Hg capture. 33 refs., 5 figs., 7 tabs.

  15. Combined Anterolateral, Anterior, and Anteromedial Ankle Impingement in an Adolescent Soccer Player-A Case Report and Review of the Literature.

    Science.gov (United States)

    Cosma, Dan I; Vasilescu, Dana E; Corbu, Andrei; Todor, Adrian; Valeanu, Madalina; Ulici, Alexandru

    2018-01-24

    A unique case of combined anterolateral, anterior, and anteromedial ankle impingement in an adolescent soccer player is presented in this article. To the best of our knowledge, this is the only report of circumferential, massive, anterior ankle impingement in children described in the literature. The importance of proper diagnosis and treatment of such a lesion is illustrated in this case report. We also emphasize that clinical examination combined with 3D computed tomography scan reconstruction is an excellent and cost-effective imaging modality that can help with the diagnosis of anterior ankle impingement. Finally, open surgical treatment showed excellent results in an elite athlete.

  16. Cam-type femoral-acetabular impingement: is the alpha angle the best MR arthrography has to offer?

    International Nuclear Information System (INIS)

    Lohan, Derek G.; Seeger, Leanne L.; Motamedi, Kambiz; Sayre, James; Hame, Sharon

    2009-01-01

    In our institutional experience, determination of the alpha (α) angle at MR arthrography as an indicator of the likelihood of cam-type femoroacetabular impingement (FAI) is fraught with inconsistency. The aims of this study were to quantify the degree of variability in and calculate the diagnostic accuracy of the α angle in suggesting a diagnosis of cam impingement, to determine the accuracy of a positive clinical impingement test, and to suggest alternative MR arthrographic measures of femoral head-neck overgrowth and determine their diagnostic utilities. We carried out a retrospective analysis of MR arthrographic studies performed during a 4-year period, combined with chart analysis, which allowed identification of 78 patients in whom surgical correlation was also available. The status of a preoperative clinical impingement test was also noted. Patients were designated as having cam-type FAI (Group A, n = 39) if intra-operative femoral head-neck junction bony osteochondroplasty/arthoscopic femoral debridement was performed. Group B (n = 39) acted as controls. Three radiologists independently and blindly performed a series of measurements (α angle and two newly proposed measurements) in each patient on two separate occasions. An α angle of greater than 55 was considered indicative of the presence of cam-type FAI. Performance values for α angle measurement were poor for each observer. There was considerable (up to 30% of the mean value) intra-observer variability between the first and second α angle measurements for each subject. Binary logistic regression analysis confirmed that the α angle is of no value in predicting the presence or absence of cam-FAI. A statistically significant difference existed between Groups A and B with regard to the newly proposed anterior femoral distance (AFD; p = 0.004). Using an AFD value of 3.60 mm or greater as being indicative of the presence of cam-FAI yields a 0.67 performance measure (95% confidence interval 0

  17. Sex Differences in Patients With CAM Deformities With Femoroacetabular Impingement: 3-Dimensional Computed Tomographic Quantification.

    Science.gov (United States)

    Yanke, Adam B; Khair, M Michael; Stanley, Robert; Walton, David; Lee, Simon; Bush-Joseph, Charles A; Espinoza Orías, Alejandro; Espinosa Orias, Alejandro A; Inoue, Nozomu; Nho, Shane J

    2015-12-01

    To determine if significant differences exist between male and female CAM deformities using quantitative 3-dimensional (3D) volume and location analysis. Retrospective analysis of preoperative computed tomographic (CT) scans for 138 femurs (69 from male patients and 69 from female patients) diagnosed with impingement from November 2009 to November 2011 was completed. Those patients who presented with hip complaints and had a history, physical examination (limited range of motion, positive impingement signs), plain radiographs (anteroposterior pelvis, 90° Dunn view, false profile view), and magnetic resonance images consistent with femoroacetabular impingement (FAI) and in whom a minimum of 6 months of conservative therapy (oral anti-inflammatory agents, physical therapy, and activity modification) had failed were indicated for arthroscopic surgery and had a preoperative CT scan. Scans were segmented, converted to point cloud data, and analyzed with a custom-written computer program. Analysis included mean CAM height and volume, head radius, and femoral version. Differences were analyzed using an unpaired t test with significance set at P position ± the 2:51 o'clock position to the 3:28 o'clock position ± the 1:59 o'clock position, with an average span from the 3:06 o'clock position ± the 1:29 o'clock position (male patients, the 11:23 o'clock position ± the 0:46 o'clock position to the 3:05 o'clock position ± the 1:20 o'clock position; female patients, the 11:33 o'clock position ± the 0:37 o'clock position to the 2:27 o'clock position ± the 0:45 o'clock position). There were no differences in the posterior (P = .60) or anterior (P = .14) extent of CAM deformities. However, the span on the clock face of the CAM deformities varied when comparing men with women (male patients, the 3:43 o'clock position ± the 1:29 o'clock position; female patients, the 2:54 o'clock position ± the 1:09 o'clock position; P = .02). Our data show that female CAM deformities

  18. The Warwick Agreement on femoroacetabular impingement syndrome (FAI syndrome): an international consensus statement.

    Science.gov (United States)

    Griffin, D R; Dickenson, E J; O'Donnell, J; Agricola, R; Awan, T; Beck, M; Clohisy, J C; Dijkstra, H P; Falvey, E; Gimpel, M; Hinman, R S; Hölmich, P; Kassarjian, A; Martin, H D; Martin, R; Mather, R C; Philippon, M J; Reiman, M P; Takla, A; Thorborg, K; Walker, S; Weir, A; Bennell, K L

    2016-10-01

    The 2016 Warwick Agreement on femoroacetabular impingement (FAI) syndrome was convened to build an international, multidisciplinary consensus on the diagnosis and management of patients with FAI syndrome. 22 panel members and 1 patient from 9 countries and 5 different specialties participated in a 1-day consensus meeting on 29 June 2016. Prior to the meeting, 6 questions were agreed on, and recent relevant systematic reviews and seminal literature were circulated. Panel members gave presentations on the topics of the agreed questions at Sports Hip 2016, an open meeting held in the UK on 27-29 June. Presentations were followed by open discussion. At the 1-day consensus meeting, panel members developed statements in response to each question through open discussion; members then scored their level of agreement with each response on a scale of 0-10. Substantial agreement (range 9.5-10) was reached for each of the 6 consensus questions, and the associated terminology was agreed on. The term 'femoroacetabular impingement syndrome' was introduced to reflect the central role of patients' symptoms in the disorder. To reach a diagnosis, patients should have appropriate symptoms, positive clinical signs and imaging findings. Suitable treatments are conservative care, rehabilitation, and arthroscopic or open surgery. Current understanding of prognosis and topics for future research were discussed. The 2016 Warwick Agreement on FAI syndrome is an international multidisciplinary agreement on the diagnosis, treatment principles and key terminology relating to FAI syndrome.Author note The Warwick Agreement on femoroacetabular impingement syndrome has been endorsed by the following 25 clinical societies: American Medical Society for Sports Medicine (AMSSM), Association of Chartered Physiotherapists in Sports and Exercise Medicine (ACPSEM), Australasian College of Sports and Exercise Physicians (ACSEP), Austian Sports Physiotherapists, British Association of Sports and Exercise

  19. Method for Measuring Cooling Efficiency of Water Droplets Impinging onto Hot Metal Discs

    Directory of Open Access Journals (Sweden)

    Joachim Søreng Bjørge

    2018-06-01

    Full Text Available The present work outlines a method for measuring the cooling efficiency of droplets impinging onto hot metal discs in the temperature range of 85 °C to 400 °C, i.e., covering the boiling regimes experienced when applying water to heated objects in fires. Stainless steel and aluminum test discs (with 50-mm diameter, 10-mm thickness, and a surface roughness of Ra 0.4 or Ra 3 were suspended horizontally by four thermocouples that were used to record disc temperatures. The discs were heated by a laboratory burner prior to the experiments, and left to cool with and without applying 2.4-mm diameter water droplets to the discs while the disc temperatures were recorded. The droplets were generated by the acceleration of gravity from a hypodermic injection needle, and hit the disc center at a speed of 2.2 m/s and a rate of 0.02 g/s, i.e., about three droplets per second. Based on the recorded rate of the temperature change, as well as disc mass and disc heat capacity, the absolute droplet cooling effect and the relative cooling efficiency relative to complete droplet evaporation were obtained. There were significant differences in the cooling efficiency as a function of temperature for the two metals investigated, but there was no statistically significant difference with respect to whether the surface roughness was Ra 0.4 or Ra 3. Aluminum showed a higher cooling efficiency in the temperature range of 110 °C to 140 °C, and a lower cooling efficiency in the temperature range of 180 °C to 300 °C compared to stainless steel. Both metals gave a maximum cooling efficiency in the range of 75% to 85%. A minimum of 5% cooling efficiency was experienced for the aluminum disc at 235 °C, i.e., the observed Leidenfrost point. However, stainless steel did not give a clear minimum in cooling efficiency, which was about 12–14% for disc temperatures above 300 °C. This simple and straightforward technique is well suited for assessing the cooling efficiency of

  20. Hip arthroscopy for femoroacetabular impingement: the changing nature and severity of associated complications over time.

    Science.gov (United States)

    Park, Myung-Sik; Yoon, Sun-Jung; Kim, Yong-Jin; Chung, Woo-Chul

    2014-08-01

    The aim of this study was to assess complications related to arthroscopy for femoroacetabular impingement (FAI) and how these complications have changed as we have gained more experience with this procedure. The authors reviewed 200 hips (197 patients). The average patient age was 44.64 years and the mean follow-up time was 28.2 months. All patients underwent hip arthroscopy in the supine position. Clinically, Modified Harris Hip Scores (MHHS) and patient satisfaction with outcome were used. We divided complications into 3 groups: Group 1 related to traction, group 2 related to surgical technique or implant failure, and group 3 related to outcomes. Clinically, the MHHS improved from 69.96 (±6.10) to 80.45 (±7.00), and patient satisfaction with the achieved outcome increased to 8.87 (±0.76). The overall complication rate was 15% (30 of 200 hips). Group 1 consisted of 4 patients with pudendal neuropraxia and 2 patients with ankle joint pain (P = .013). Group 2 consisted of 2 patients with lateral femoral cutaneous neuropraxia, 2 patients with iatrogenic labral perforations, one patient with a labral tear, and 4 patients with femoral head scuffs. There were 4 incidents of instrument breakage. Furthermore, 3 suture anchors failed, a second-degree burn occurred in one patient, and there was incomplete reshaping in 5 hips (P = .045). Group 3 included one patient with a snapping sound and heterotopic ossification. Second-look arthroscopy was performed for 5 hips. All the complications outlined in groups 1 and 2 are related to the learning curve and have statistical significance (P arthroscopy took different forms during the early learning period, but overall complication rates decreased along the learning curve. Surgical technique-related complications such as problems with suture anchors and the reshaping of cam impingements were also considered during the later stage. Level IV, therapeutic case series. Copyright © 2014 Arthroscopy Association of North America

  1. Rapid thermal processing of nano-crystalline indium tin oxide transparent conductive oxide coatings on glass by flame impingement technology

    International Nuclear Information System (INIS)

    Schoemaker, S.; Willert-Porada, M.

    2009-01-01

    Indium tin oxide (ITO) is still the best suited material for transparent conductive oxides, when high transmission in the visible range, high infrared reflection or high electrical conductivity is needed. Current approaches on powder-based printable ITO coatings aim at minimum consumption of active coating and low processing costs. The paper describes how fast firing by flame impingement is used for effective sintering of ITO-coatings applied on glass. The present study correlates process parameters of fast firing by flame impingement with optoelectronic properties and changes in the microstructure of suspension derived nano-particulate films. With optimum process parameters the heat treated coatings had a sheet resistance below 0.5 kΩ/ □ combined with a transparency higher than 80%. To characterize the influence of the burner type on the process parameters and the coating functionality, two types of methane/oxygen burner were compared: a diffusion burner and a premixed burner

  2. Survey of fish impingement at power plants in the United States. Volume III. Estuaries and coastal waters

    International Nuclear Information System (INIS)

    Stupka, R.C.; Sharma, R.K.

    1977-03-01

    Impingement of fish at cooling-water intakes of 32 power plants, located on estuaries and coastal waters has been surveyed and data are presented. Descriptions of site, plant, and intake design and operation are provided. Reports in this volume summarize impingement data for individual plants in tabular and histogram formats. Information was available from differing sources such as the utilities themselves, public documents, regulatory agencies, and others. Thus, the extent of detail in the reports varies greatly from plant to plant. Histogram preparation involved an extrapolation procedure that has inadequacies. The reader is cautioned in the use of information presented in this volume to determine intake-design acceptability or intensity of impacts on ecosystems. No conclusions are presented herein; data comparisons are made in Volume IV

  3. The anti-corrosion behavior under multi-factor impingement of Hastelloy C22 coating prepared by multilayer laser cladding

    Science.gov (United States)

    Chen, Lin; Bai, Shu-Lin

    2018-04-01

    Hastelloy C22 coating was prepared on substrate of Q235 steel by high power multilayer laser cladding. The microstructure, hardness and anti-corrosion properties of coating were investigated. The corrosion tests in 3.5% NaCl solution were carried out with variation of impingement angle and velocity, and vibration frequency of sample. The microstructure of coating changes from equiaxed grain at the top surface to dendrites oriented at an angle of 60° to the substrate inside the coating. The corrosion rate of coating increases with the increase of impingement angle and velocity, and vibrant frequency of sample. Corrosion mechanisms relate to repassivation and depassivation of coating according to electrochemical measurements. Above results show that multilayer laser cladding can endow Hastelloy C22 coating with fine microstructures, high hardness and good anti-corrosion performances.

  4. Slurry Erosion Studies on Surface Modified 13Cr-4Ni Steels: Effect of Angle of Impingement and Particle Size

    Science.gov (United States)

    Manisekaran, T.; Kamaraj, M.; Sharrif, S. M.; Joshi, S. V.

    2007-10-01

    Hydroturbine steels, such as 13Cr-4Ni martensitic steels, are generally subjected to heavy-erosive wear and loss of efficiency due to solid particulate entrainment in the water. Surface-modified steels have proven to give better performance in terms of erosive wear resistance. In the present study, an attempt is made to investigate the effect of angle of impingement and particle size on slurry-jet erosion behavior of pulsed plasma nitrided and laser hardened 13Cr-4Ni steels. Laser hardening process has shown good performance at all angles of impingement due to martensitic transformation of retained austenite. Plastic deformation mode of material removal was also an evident feature of all laser-hardened surface damage locations. However, pulsed-plasma nitrided steels have exhibited chip formation and micro-cutting mode of erosive wear. Erosion with 150-300 μm size was twice compared to 150 μm size slurry particulates.

  5. Mechanism of jet-flutter: self-induced oscillation of an upward plane jet impinging on a free surface

    International Nuclear Information System (INIS)

    Madarame, Haruki; Iida, Masao

    1998-01-01

    An upward plane jet impinging on the free surface of a shallow rectangular tank oscillates without any external periodic force. The movement of the impinging point leaves additional fluid mass on the surface behind the point, which does not balance the momentum supplied by the jet. The imbalance generates propagating waves, and a surface level gap appears there. The level gap is flattened not by the waves but by the vertical motion of water columns. The imbalance causes lateral displacement of jet, which in turn causes the imbalance, forming a positive feedback loop. The above model explains well why the frequency corresponds to that of water column oscillation in a partitioned tank with the same water depth, and the oscillation region has a wide range above a certain velocity limit determined by the water depth. (author)

  6. Survey of fish impingement at power plants in the United States. Volume III. Estuaries and coastal waters

    Energy Technology Data Exchange (ETDEWEB)

    Stupka, Richard C.; Sharma, Rajendra K.

    1977-03-01

    Impingement of fish at cooling-water intakes of 32 power plants, located on estuaries and coastal waters has been surveyed and data are presented. Descriptions of site, plant, and intake design and operation are provided. Reports in this volume summarize impingement data for individual plants in tabular and histogram formats. Information was available from differing sources such as the utilities themselves, public documents, regulatory agencies, and others. Thus, the extent of detail in the reports varies greatly from plant to plant. Histogram preparation involved an extrapolation procedure that has inadequacies. The reader is cautioned in the use of information presented in this volume to determine intake-design acceptability or intensity of impacts on ecosystems. No conclusions are presented herein; data comparisons are made in Volume IV.

  7. Estimation of energy saving thanks to a reduced-model-based approach: Example of bread baking by jet impingement

    International Nuclear Information System (INIS)

    Alamir, M.; Witrant, E.; Della Valle, G.; Rouaud, O.; Josset, Ch.; Boillereaux, L.

    2013-01-01

    In this paper, a reduced order mechanistic model is proposed for the evolution of temperature and humidity during French bread baking. The model parameters are identified using experimental data. The resulting model is then used to estimate the potential energy saving that can be obtained using jet impingement technology when used to increase the heat transfer efficiency. Results show up to 16% potential energy saving under certain assumptions. - Highlights: ► We developed a mechanistic model of heat and mass transfer in bread including different and multiple energy sources. ► An optimal control system permits to track references trajectories with a minimization of energy consuming. ► The methodology is evaluated with jet impingement technique. ► Results show a significant energy saving of about 17% of energy with reasonable actuator variations

  8. Evaluation of a barrier net used to mitigate fish impingement at a Hudson River power plant intake

    International Nuclear Information System (INIS)

    Hutchison, J.B.; Matousek, J.A.

    1988-01-01

    A multifilament nylon net of 0.95-cm bar mesh was deployed as a physical barrier to fish in front of the Bowline Point power plant cooling water intake on the Hudson River from 1976 to 1985. The barrier net was deployed during the historical peak impingement months of October-May. The primary species impinged on the intake screens during this period were young-of-year and yearling white perch, striped bass, rainbow smelt, alewife, blue-back herring, and American shad, generally ranging from 5 to 10 cm in total length. When the barrier net was deployed, median impingement of all fish was 91% lower than during comparable periods before the net was installed. A mark-recapture population estimate indicated that 230,000 yearling striped bass and white perch were in the embayment outside the net in April 1982; over a 9-d study period, only 1.6% of this estimated population was impinged. Concurrent survival probability studies of fish marked and released at locations inside and outside the barrier net showed that fish released inside had 72% lower survival (P

  9. Investigation of Three-Dimensional Axisymmetric Unsteady Stagnation-Point Flow and Heat Transfer Impinging on an Accelerated Flat Plate

    OpenAIRE

    ali shokrgozar abbasi; Asghar Baradaran Rahimi; Hamidreza Mozayeni

    2016-01-01

    General formulation and solution of Navier-Stokes and energy equations are sought in the study of threedimensional axisymmetric unsteady stagnation-point flow and heat transfer impinging on a flat plate when the plate is moving with variable velocity and acceleration towards the main stream or away from it. As an application, among others, this accelerated plate can be assumed as a solidification front which is being formed with variable velocity. An external fluid, along z - directi...

  10. The estimation of dynamic contact angle of ultra-hydrophobic surfaces using inclined surface and impinging droplet methods

    Science.gov (United States)

    Jasikova, Darina; Kotek, Michal

    2014-03-01

    The development of industrial technology also brings with optimized surface quality, particularly where there is contact with food. Application ultra-hydrophobic surface significantly reduces the growth of bacteria and facilitates cleaning processes. Testing and evaluation of surface quality are used two methods: impinging droplet and inclined surface method optimized with high speed shadowgraphy, which give information about dynamic contact angle. This article presents the results of research into new methods of measuring ultra-hydrophobic patented technology.

  11. Conservative surgical and microsurgical techniques for the management of dental implants that impinge on the inferior alveolar nerve.

    Science.gov (United States)

    Gennaro, Paolo; Chisci, Glauco; Gabriele, Guido; Iannetti, Giorgio

    2014-07-01

    Loss of sensation in the lip after insertion of an implant is annoying. The aim of this paper was to describe two techniques for management of osseointegrated dental implants that impinge on the mandibular nerve, the purpose of which is to improve sensation without unscrewing the dental implant. Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

  12. Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit

    Energy Technology Data Exchange (ETDEWEB)

    Tuite, Michael J; Petersen, Brian D; Wise, Steven M [University of Wisconsin Hospital and Clinics, Department of Radiology, Madison, WI (United States); Fine, Jason P [University of Wisconsin Hospital and Clinics, Department of Biostatistics, Madison, WI (United States); Kaplan, Lee D; Orwin, John F [University of Wisconsin Hospital and Clinics, Department of Orthopedic Surgery, Madison, WI (United States)

    2007-06-15

    To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 (SD 27 ) for the controls and 94 (SD 38 ) for the athletes (P = 0.002). Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement. (orig.)

  13. The direct environmental impact of hip arthroscopy for femoroacetabular impingement: a surgical waste audit of five cases

    OpenAIRE

    de SA, Darren; Stephens, Kellee; Kuang, Michelle; Simunovic, Nicole; Karlsson, Jon; Ayeni, Olufemi R.

    2016-01-01

    Health care facilities produce significant waste (2200?kg/bed/year) creating 2% of greenhouse gas emissions and 1% total solid waste nationwide, with 20?70% of waste coming from operating rooms. We performed a waste audit of hip arthroscopy for femoroacetabular impingement (FAI) to understand its environmental impact and identify areas for greening practices. A waste audit of five hip arthroscopy procedures for FAI was performed. All waste was collected and separated into six waste streams in...

  14. Shoulder MR arthrography of the posterior labrocapsular complex in overhead throwers with pathologic internal impingement and internal rotation deficit

    International Nuclear Information System (INIS)

    Tuite, Michael J.; Petersen, Brian D.; Wise, Steven M.; Fine, Jason P.; Kaplan, Lee D.; Orwin, John F.

    2007-01-01

    To determine if overhead-throwing athletes with internal impingement pain and internal rotation deficit have thickening of the posterior inferior labrocapsular complex on MR arthrogram images. This study was approved and a waiver of consent granted by our institutional review board. Twenty-six overhead-throwing athletes with internal impingement pain and internal rotation deficit, and 26 controls who had undergone MR arthrograms, were retrospectively examined. The MR studies were combined and read in a blind fashion. On an axial image through the posteroinferior glenoid rim, the readers measured the labral length, capsule-labrum length, and the posterior recess angle. A t-test was used to determine statistical significance. The mean labral length was 4.9 mm [standard deviation (SD) 1.4 mm] for the controls, and 6.4 mm (SD 1.6 mm) for the athletes (P = 0.001). The mean capsule-labrum length was 5.4 mm (SD 2.1 mm) for the controls, and 8.8 mm (SD 2.9 mm) for the athletes (P < 0.001). The mean posterior recess angle measured 65 (SD 27 ) for the controls and 94 (SD 38 ) for the athletes (P = 0.002). Overhead-throwing athletes with internal impingement pain and internal rotation deficit tend to have a thicker labrum and a shallower capsular recess in the posterior inferior shoulder joint than do non-overhead-throwing athletes. In many, the posteroinferior capsule is also thickened. These MR findings should alert the radiologist to closely inspect the posterior cuff and posterosuperior labrum for the tears associated with internal impingement. (orig.)

  15. Femoroacetabular cam-type impingement: Diagnostic sensitivity and specificity of radiographic views compared to radial MRI

    International Nuclear Information System (INIS)

    Domayer, S.E.; Ziebarth, K.; Chan, J.; Bixby, S.; Mamisch, T.C.; Kim, Y.J.

    2011-01-01

    Purpose: To retrospectively assess the diagnostic sensitivity of 45° Dunn view and cross-table lateral radiographs for the assessment of cam deformity by comparison with radial MRI. Materials and methods: 60 cases with radiographs (38 a–p and 45° Dunn views, 22 a–p and cross-table lateral views) and radial MRI were assessed. Alpha angle measurements were obtained both for radiographs and radial MRI. Statistics included frequency analysis, bivariate linear correlation analyses of MRI and radiograph measurements and cross-table analyses testing for the sensitivity and specificity of radiographs for the detection of an alpha angle larger than 55°. Results: 53.3% had the maximum alpha angle in the superior–anterior aspect of the femoral head–neck junction. Cam deformity was found in 45/60 cases (75%) in radial MRI. Pearson correlation demonstrated the Dunn view was most accurate for the superior–anterior aspect (.772, P < .001). The cross-table lateral views were best suited for the anterior–superior aspect (.511, P < .05). The sensitivity for cam deformity in the Dunn view was 96.4% vs. 70.6% in the cross-table lateral view. Conclusion: The 45° Dunn view can improve the first line of impingement diagnostics. Radial MRI however remains indispensable for pre-operative planning and the evaluation of symptomatic cases without obvious deformity.

  16. Hip morphometry of femoroacetabular impingement pattern in patients with ankylosing spondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Yoon; Lee, Eu Gene; Choi, Jung Ah [Dept. of Radiology, Seoul National University Bundang Hospital, Seongnam (Korea, Republic of)

    2015-06-15

    To analyze hip morphometry of femoroacetabular impingement (FAI) pattern in patients with ankylosing spondylitis (AS) and correlate them with sacroiliitis grades. 384 patients with AS were analyzed regarding demographics, radiologic signs of FAI for hip involvement, and sacroiliitis grades. FAI was classified into 3 types according to alpha angle, lateral center-edge angle and pistol grip deformity. Sacroiliitis was graded according to the New York criteria. Prevalence of FAI morphometry types was determined and evaluated for association with sacroiliitis grades. Statistical analysis regarding numerical variables, including age, sacroiliitis score using t-test, sacroiliitis score in three groups using Kruskal-Wallis test and Mann-Whitney U-test, corrected by Bonferroni methods for post hoc analysis was done. Among 384 patients, 141 (36.7%) had FAI morphometry. Male predominance was found in group with FAI pattern involvement (87.2%) (p = 0.000). Pincer type (20.6%) was the most common. Hip involvement group also showed greater sacroiliitis score (2.49 vs. 1.75, p = 0.000). Combined-type had greater sacroiliitis score compared with others (p = 0.002, 0.003). FAI morphometry was frequent in hips of AS patients (36.7%), especially pincer type, more frequent in male, and associated with significantly greater grade of sacroiliitis; combined type FAI pattern had greater sacroiliitis score.

  17. Comparison of Inconel 625 and Inconel 600 in resistance to cavitation erosion and jet impingement erosion

    Energy Technology Data Exchange (ETDEWEB)

    Hu, H.X. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Science, 62 Wencui Road, Shenyang 110016 (China); Zheng, Y.G., E-mail: ygzheng@imr.ac.c [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Science, 62 Wencui Road, Shenyang 110016 (China); Qin, C.P. [State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Science, 62 Wencui Road, Shenyang 110016 (China)

    2010-10-15

    Liquid droplet erosion (LDE), which often occurs in bellows made of nickel-based alloys, threatens the security operation of the nuclear power plant. As the candidate materials of the bellows, Inconel 600 and Inconel 625 were both tested for resistance to cavitation erosion (CE) and jet impingement erosion (JIE) through vibratory cavitation equipment and a jet apparatus for erosion-corrosion. Cumulative mass loss vs. exposure time was used to evaluate the erosion rate of the two alloys. The surface and cross-sectional morphologies before and after the erosion tests were observed by scanning electron microscopy (SEM), the inclusions were analyzed by an energy dispersive spectroscopy (EDS), and the surface roughness was also measured by surface roughness tester to illustrate the evolution of erosion process. The results show that the cumulative mass loss of CE of Inconel 625 is about 1/6 that of Inconel 600 and the CE incubation period of the Inconel 625 is 4 times as long as that of the Inconel 600. The micro-morphology evolution of CE process illustrates that the twinning and hardness of the Inconel 625 plays a significant role in CE. In addition, the cumulative mass loss of JIE of Inconel 625 is about 2/3 that of Inconel 600 at impacting angle of 90{sup o}, and almost equal to that of the Inconel 600 at impacting angle of 30{sup o}. Overall, the resistance to CE and JIE of Inconel 625 is much superior to that of Inconel 600.

  18. Comparison of Inconel 625 and Inconel 600 in resistance to cavitation erosion and jet impingement erosion

    International Nuclear Information System (INIS)

    Hu, H.X.; Zheng, Y.G.; Qin, C.P.

    2010-01-01

    Liquid droplet erosion (LDE), which often occurs in bellows made of nickel-based alloys, threatens the security operation of the nuclear power plant. As the candidate materials of the bellows, Inconel 600 and Inconel 625 were both tested for resistance to cavitation erosion (CE) and jet impingement erosion (JIE) through vibratory cavitation equipment and a jet apparatus for erosion-corrosion. Cumulative mass loss vs. exposure time was used to evaluate the erosion rate of the two alloys. The surface and cross-sectional morphologies before and after the erosion tests were observed by scanning electron microscopy (SEM), the inclusions were analyzed by an energy dispersive spectroscopy (EDS), and the surface roughness was also measured by surface roughness tester to illustrate the evolution of erosion process. The results show that the cumulative mass loss of CE of Inconel 625 is about 1/6 that of Inconel 600 and the CE incubation period of the Inconel 625 is 4 times as long as that of the Inconel 600. The micro-morphology evolution of CE process illustrates that the twinning and hardness of the Inconel 625 plays a significant role in CE. In addition, the cumulative mass loss of JIE of Inconel 625 is about 2/3 that of Inconel 600 at impacting angle of 90 o , and almost equal to that of the Inconel 600 at impacting angle of 30 o . Overall, the resistance to CE and JIE of Inconel 625 is much superior to that of Inconel 600.

  19. Ischiofemoral impingement: evaluation with new MRI parameters and assessment of their reliability

    Energy Technology Data Exchange (ETDEWEB)

    Tosun, Ozgur; Algin, Oktay; Cay, Nurdan; Karaoglanoglu, Mustafa [Ankara Ataturk Education and Research Hospital, Department of Radiology, Ankara (Turkey); Yalcin, Nadir [University of California, Department of Orthopaedic Surgery, San Francisco, CA (United States); Ocakoglu, Gokhan [Uludag University Medical Faculty, Biostatistics Department, Bursa (Turkey)

    2012-05-15

    The aim of this study was to describe the magnetic resonance imaging (MRI) findings in patients with ischiofemoral impingement (IFI) and to evaluate the reliability of these MRI findings. Seventy hips of 50 patients with hip pain and quadratus femoris muscle (QFM) edema and 38 hips of 30 control cases were included in the study. The QFM edema and fatty replacement were assessed visually. Ischiofemoral space (IFS), quadratus femoris space (QFS), inclination angle (IA), hamstring tendon area (HTA), and total quadratus femoris muscle volume (TQFMV) measurements were performed independently by two musculoskeletal radiologists. The intra- and interobserver reliabilities were obtained for quantitative variables. IFS, QFS, and TQFMV values of the patient group were significantly lower than those of controls (P < 0.001). HTA and IA measurements of the patient group were also significantly higher than in controls (P < 0.05). The QFM fatty replacement grades were significantly higher in the patient group than in the control group (P < 0.001). Inter- and intra-observer reliabilities were strong for all continuous variables. Clinicians and radiologists should be aware of IFI in patients with hip or groin pain, and MRI should be obtained for the presence of the QFM edema/fatty replacement, narrowing of the IFS-QFS, and other features that may help in the clinical diagnosis of IFI for the proper diagnosis and treatment of the disease. (orig.)

  20. Modified Regression Rate Formula of PMMA Combustion by a Single Plane Impinging Jet

    Directory of Open Access Journals (Sweden)

    Tsuneyoshi Matsuoka

    2017-01-01

    Full Text Available A modified regression rate formula for the uppermost stage of CAMUI-type hybrid rocket motor is proposed in this study. Assuming a quasi-steady, one-dimensional, an energy balance against a control volume near the fuel surface is considered. Accordingly, the regression rate formula which can calculate the local regression rate by the quenching distance between the flame and the regression surface is derived. An experimental setup which simulates the combustion phenomenon involved in the uppermost stage of a CAMUI-type hybrid rocket motor was constructed and the burning tests with various flow velocities and impinging distances were performed. A PMMA slab of 20 mm height, 60 mm width, and 20 mm thickness was chosen as a sample specimen and pure oxygen and O2/N2 mixture (50/50 vol.% were employed as the oxidizers. The time-averaged regression rate along the fuel surface was measured by a laser displacement sensor. The quenching distance during the combustion event was also identified from the observation. The comparison between the purely experimental and calculated values showed good agreement, although a large systematic error was expected due to the difficulty in accurately identifying the quenching distance.