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Sample records for facet joint forces

  1. Determination of contact force at facet joint with different sagittal orientation under shearing loads:a finite element analysis

    Institute of Scientific and Technical Information of China (English)

    刘耀升; 陈其昕; 刘蜀彬

    2008-01-01

    with different facet joint angle.[Conclusion]The spatial orientation and geometric forms of the coronal facet articular surfaces are more effective in restricting motion in transversal and sagittal planes while assuming a minor role in resisting axial force or motion than sagittal facet articular surface.It Was presumed that anterior shear force play a more prominent contribution on the degeneration of the facet joint with coronal articular surface compared with posterior shear force.

  2. Types of subtalar joint facets.

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    Jung, Min-Ho; Choi, Byoung Young; Lee, Ji Yong; Han, Chang Sung; Lee, Jin Suk; Yang, Young Chul; Cho, Byung Pil

    2015-08-01

    Articular facets of the clinical subtalar joint (CSTJ) were analyzed using a total of 118 (right 57, left 61) dry, paired calcanei and tali from 68 Korean adult cadavers. The CSTJ facets were classified into the following three types depending on their continuity: type A, all three facets are separated; type B, the anterior and middle facets are partially connected; and type C, the anterior and middle facets are fused to form a single facet. The continuity between the anterior and middle facets was represented by the degree of separation (DS), which ranged between 2.00 (type A) and 1.00 (type C). Type A was most common (39.0 %) in calcanei and rarest (11.0 %) in tali. Matching of calcaneus-talus pairs yielded five combined types: A-A (11.0 %), A-B (28.0 %), B-B (18.6 %), B-C (13.6 %), and C-C (28.8 %). The mean DS was slightly greater in calcanei (1.53) than in tali (1.32), and decreased in the order of types A-A, A-B, B-B, B-C, and C-C. The intersecting angles between the anterior and middle facets, which are related to the mobility of the CSTJ, were inversely related to the DS. These findings indicate that the anterior and middle facets are fused more frequently in tali than in calcanei, and combinations of different CSTJ facet types (A-B, B-C) exist over 40 % of feet. Our results indicate that types with a smaller DS (such as B-C and C-C) are relatively mobile but less stable compared to those with a greater DS (such as A-A and A-B).

  3. Arthrography of the lumber facet joint and facet block

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    Cho, Hee Kyung; Chung, Tae Sub; Kim, Young Soo; Park, Hyung Chun; Moon, Jae Ho; Suh, Jung Ho; Kim, Dong Ik [Yonsei University College of Medicine, Seoul (Korea, Republic of)

    1988-12-15

    In spite of numerous clinical and patho-anatomical studied made in the past, there are still different opinions concerning the mechanism of low back pain. We have focused attention on the posterior structures as an alternative source of low back pain with sciatica. So we have studied and analyzed the finding of arthrography of facet joint and effect of the injection of methyprednisolone acetate suspension (Depomedrol) 20mg into the each facet joint. Our results are as follows: 1. Abnormal findings of facet joint arthrogram were degenerative osteoarthritis of facet joint (70.5%), synovial cyst (11.8%), accessory bone (11.8%), and spondylolysis (5.9%). 2. The mean facet angulations of patients of facet syndrome were abnormal on lower lumbar facet joint in 9 of 13 cases (69.2%). 3. On initial assessment, 11 of 17 cases (64.7%) showed complete relief and one month later, 6 of 11 cases (35.3%) showed continuous relief, after steroid injection.

  4. [Septic arthritis of thoracic facet joint].

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    Ben Abdelghani, K; Gérard-Dran, D; Combe, B

    2009-08-01

    Septic arthritis of the facet joint is a rare condition. We report a case of septic arthritis of both a thoracic facet joint and a wrist. Clinical manifestations were consistent with a spondylodiscitis. Magnetic resonance imaging of the spine demonstrated infection of facet joints of T1 and T2. A surgical biopsy of the wrist isolated a type B streptococcus. The same organism was found in urine culture. The patient had an uneventful recovery on antibiotics.

  5. Computed Tomography of the lumbar facet joints

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    Choi, Mi Ryoung; Kim, Yung Soon; Lee, Joo Hyuk; Jeon, Hae Sang; Kim, Dae Yung [Kang Nam General Hospital, Seoul (Korea, Republic of)

    1989-08-15

    The lumbar facet disease is a frequently overlooked cause of sciatic pain, but the lumbar facet joints are well-recognized source of low back pain and radiating leg pain which can be confused with sciatica due to herniated disc. We measured the angulation of the facet joints on axial spine CT films in 149 cases which contains 41 normal group and 108 abnormal group and studied the relationship between the angulation and degeneration of the facets, the asymmetry of each sided facets and facet degeneration, the asymmetry and disc protrusion, and the asymmetry and annular bulging of the disc. The results were as follows: 1. Facet angulation in abnormal group were more sagittally oriented than the normal group. 2. The angulation of right facet was more sagittally oriented than the left in L4-5 level of abnormal group. 3. Degeneration of facet joints occur asymmetrically, and the more facet joint degenerates, the more it orients sagittally, particularly in L4-5. 4. Asymmetry in facet joint degeneration and unilateral disc protrusion of L5-SI level is greater than the normal gro0008.

  6. Isolated Facet Joint Fracture as a Cause of Chronic Low Back Pain and Sciatica

    Directory of Open Access Journals (Sweden)

    Robert W Teasell

    1996-01-01

    Full Text Available A case of facet joint fracture following a rear-end motor vehicle accident who presented with chronic low back pain and sciatica is outlined. Diagnosis was made with 99Tc nuclear bone scan and was confirmed on computed tomographic scan after diagnosis with regular radiographs had failed. Facetectomy relieved pain but led to symptoms related to asymmetric load on the opposite facet joint. Symptoms were substantially relieved with a facet joint deinnervation procedure. Facet joint fracture was felt to occur as a consequence of compression forces on the facet joint at the time of impact.

  7. The effect of different design concepts in lumbar total disc arthroplasty on the range of motion, facet joint forces and instantaneous center of rotation of a L4-5 segment.

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    Schmidt, Hendrik; Midderhoff, Stefan; Adkins, Kyle; Wilke, Hans-Joachim

    2009-11-01

    Although both unconstrained and constrained core lumbar artificial disc designs are in clinical use, the effect of their design on the range of motion, center of rotations, and facet joint forces is not well understood. It is assumed that the constrained configuration causes a fixed center of rotation with high facet forces, while the unconstrained configuration leads to a moving center of rotation with lower loaded facets. The authors disagree with both assumptions and hypothesized that the two different designs do not lead to substantial differences in the results. For the different implant designs, a three-dimensional finite element model was created and subsequently inserted into a validated model of a L4-5 lumbar spinal segment. The unconstrained design was represented by two implants, the Charité disc and a newly developed disc prosthesis: Slide-Disc. The constrained design was obtained by a modification of the Slide-Disc whereby the inner core was rigidly connected to the lower metallic endplate. The models were exposed to an axial compression preload of 1,000 N. Pure unconstrained moments of 7.5 Nm were subsequently applied to the three anatomical main planes. Except for extension, the models predicted only small and moderate inter-implant differences. The calculated values were close to those of the intact segment. For extension, a large difference of about 45% was calculated between both Slide-Disc designs and the Charité disc. The models predicted higher facet forces for the implants with an unconstrained core compared to an implant with a constrained core. All implants caused a moving center of rotation. Except for axial rotation, the unconstrained and constrained configurations mimicked the intact situation. In axial rotation, only the Slide- Disc with mobile core reproduced the intact behavior. Results partially support our hypothesis and imply that different implant designs do not lead to strong differences in the range of motion and the location

  8. Load Rate of Facet Joints at the Adjacent Segment Increased After Fusion

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    Hui Li

    2015-01-01

    Full Text Available Background: The cause of the adjacent segment degeneration (ASD after fusion remains unknown. It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion. This increase of stress rate may lead to tissue injury. Thus far, the load rate of the adjacent segment facet joint after fusion remains unclear. Methods: Six C2-C7 cadaveric spine specimens were loaded under four motion modes: Flexion, extension, rotation, and lateral bending, with a pure moment using a 6° robot arm combined with an optical motion analysis system. The Tecscan pressure test system was used for testing facet joint pressure. Results: The contact mode of the facet joints and distributions of the force center during different motions were recorded. The adjacent segment facet joint forces increased faster after fusion, compared with intact conditions. While the magnitude of pressures increased, there was no difference in distribution modes before and after fusion. No pressures were detected during flexion. The average growth velocity during extension was the fastest and was significantly faster than lateral bending. Conclusions: One of the reasons for cartilage injury was the increasing stress rate of loading. This implies that ASD after fusion may be related to habitual movement before and after fusion. More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

  9. Load Rate of Facet Joints at the Adjacent Segment Increased After Fusion

    Institute of Scientific and Technical Information of China (English)

    Hui Li; Bao-Qing Pei; Jin-Cai Yang; Yong Hai; De-Yu Li; Shu-Qin Wu

    2015-01-01

    Background:The cause of the adjacent segment degeneration (ASD) after fusion remains unknown.It is reported that adjacent facet joint stresses increase after anterior cervical discectomy and fusion.This increase of stress rate may lead to tissue injury.Thus far,the load rate of the adjacent segment facet joint after fusion remains unclear.Methods:Six C2-C7 cadaveric spine specimens were loaded under four motion modes:Flexion,extension,rotation,and lateral bending,with a pure moment using a 6° robot arm combined with an optical motion analysis system.The Tecscan pressure test system was used for testing facet joint pressure.Results:The contact mode of the facet joints and distributions of the force center during different motions were recorded.The adjacent segment facet joint forces increased faster after fusion,compared with intact conditions.While the magnitude of pressures increased,there was no difference in distribution modes before and after fusion.No pressures were detected during flexion.The average growth velocity during extension was the fastest and was significantly faster than lateral bending.Conclusions:One of the reasons for cartilage injury was the increasing stress rate of loading.This implies that ASD after fusion may be related to habitual movement before and after fusion.More and faster extension is disadvantageous for the facet joints and should be reduced as much as possible.

  10. Facet joint changes after application of lumbar nonfusion dynamic stabilization.

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    Lee, Soo Eon; Jahng, Tae-Ahn; Kim, Hyun Jib

    2016-01-01

    OBJECTIVE The long-term effects on adjacent-segment pathology after nonfusion dynamic stabilization is unclear, and, in particular, changes at the adjacent facet joints have not been reported in a clinical study. This study aims to compare changes in the adjacent facet joints after lumbar spinal surgery. METHODS Patients who underwent monosegmental surgery at L4-5 with nonfusion dynamic stabilization using the Dynesys system (Dynesys group) or transforaminal lumbar interbody fusion with pedicle screw fixation (fusion group) were retrospectively compared. Facet joint degeneration was evaluated at each segment using the CT grading system. RESULTS The Dynesys group included 15 patients, while the fusion group included 22 patients. The preoperative facet joint degeneration CT grades were not different between the 2 groups. Compared with the preoperative CT grades, 1 side of the facet joints at L3-4 and L4-5 had significantly more degeneration in the Dynesys group. In the fusion group, significant facet joint degeneration developed on both sides at L2-3, L3-4, and L5-S1. The subjective back and leg pain scores were not different between the 2 groups during follow-up, but functional outcome based on the Oswestry Disability Index improved less in the fusion group than in the Dynesys group. CONCLUSIONS Nonfusion dynamic stabilization using the Dynesys system had a greater preventative effect on facet joint degeneration in comparison with that obtained using fusion surgery. The Dynesys system, however, resulted in facet joint degeneration at the instrumented segments and above. An improved physiological nonfusion dynamic stabilization system for lumbar spinal surgery should be developed.

  11. Uncovertebral joint injury in cervical facet dislocation: the headphones sign

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    Palmieri, Francesco; Cassar-Pullicino, Victor N.; Dell' Atti, Claudia; Lalam, Radhesh K.; Tins, Bernhard J.; Tyrrell, Prudencia N.M.; McCall, Iain W. [Robert Jones and Agnes Hunt Orthopaedic and District Hospital, Department of Radiology, Oswestry, England (United Kingdom)

    2006-06-15

    The purpose of our study is to demonstrate the uncovertebral mal-alignment as a reliable indirect sign of cervical facet joint dislocation. We examined the uncovertebral axial plane alignment of 12 patients with unilateral and bilateral cervical facet joint dislocation (UCFJD and BCFJD, respectively), comparing its frequency to the reverse hamburger bun sign on CT and MR axial images. Of the seven cases with BCFJD, five clearly demonstrated the diagnostic reverse facet joint hamburger bun sign on CT and MR images, but in two cases this sign was not detectable. In the five cases with UCFJD, four demonstrated the reverse hamburger bun sign on both CT and MRI. In one case the reverse hamburger bun sign was not seen adequately with either image modality, but the facet dislocation was identified on sagittal imaging. The uncovertebral mal-alignment was detected in all 12 cases. Normally, the two components of the uncovertebral joint enjoy a concentric relationship that in the axial plane is reminiscent of the relationship of headphones with the wearer's head. We name this appearance the 'headphones' sign. Radiologists should be aware of the headphones sign as a reliable indicator of facet joint dislocation on axial imaging used in the assessment of cervical spine injuries. (orig.)

  12. Three-dimensional evaluation of the facet joints

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    Folio, Les R.

    1990-04-01

    Computerized tomography and magnetic resonance imaging nave revolurionalized analysis of vertebral anatomy and pathology. Further advances with 3-dimensional imaging have recently become an important adjunct for diagnosis and treatment in structural abnormalities. Facets are intimately related to their surrounding musculature and malalignment may cause pain directly or indirectly. High resolution 3-dimensional reformations of CT Scans give us new insight on structure and function of facet joints, since their motion and architecture are ever complex. It is well documented in the literature that facet joint biomecnanics is a partial contributor to the myriad at causes of low back The term "facet Joint syndrome" was coined in 1933 by GhorMley.3 The osteopathic lesion complex is well defined by LeRoy and McCole and comparison of roentgenographic findings before and after manipulation has teen described by Long and Lioyd.4,5 since alterations in facet biamechanics are an important aspect of osteopathic manipulative therapy (OT), 3-dimensional hign resolution imaging will prove to be a great asset in osteopathic research. Rotating the spine allows for different viewing perspectives to provide optimal and consistent measurements of the facet joint. Rotations are performed on the X, Y and 7, axis and measurements pre and post-manipulation are performed and compared on matching axis and perspectives. Rotation about the X, Y and Z axis help appreciate the 3-dimensionality of the vertebral column to project to the viewer a feeling that the spine is floating in space before them. This does give the viewer a 3-D understanding of the object however, only at a perspective at a Lime.

  13. Augmented reality needle guidance improves facet joint injection training

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    Ungi, Tamas; Yeo, Caitlin T.; U-Thainual, Paweena; McGraw, Robert C.; Fichtinger, Gabor

    2011-03-01

    PURPOSE: The purpose of this study was to determine if medical trainees would benefit from augmented reality image overlay and laser guidance in learning how to set the correct orientation of a needle for percutaneous facet joint injection. METHODS: A total of 28 medical students were randomized into two groups: (1) The Overlay group received a training session of four insertions with image and laser guidance followed by two insertions with laser overlay only; (2) The Control group was trained by carrying out six freehand insertions. After the training session, needle trajectories of two facet joint injections without any guidance were recorded by an electromagnetic tracker and were analyzed. Number of successful needle placements, distance covered by needle tip inside the phantom and procedural time were measured to evaluate performance. RESULTS: Number of successful placements was significantly higher in the Overlay group compared to the Control group (85.7% vs. 57.1%, p = 0.038). Procedure time and distance covered inside phantom have both been found to be less in the Overlay group, although not significantly. CONCLUSION: Training with augmented reality image overlay and laser guidance improves the accuracy of facet joint injections in medical students learning image-guided facet joint needle placement.

  14. Prevalence of cervical facet joint pain in chronic neck pain.

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    Manchikanti, Laxmaiah; Singh, Vijay; Rivera, Jose; Pampati, Vidyasagar

    2002-07-01

    Neck pain is considered to be one of the most common chronic pain conditions in modern society. Various structures identified as capable of transmitting pain in the cervical spine include facet joints, intervertebral discs, nerve root dura, ligaments, fascia, and muscles. The prevalence of cervical facet joint pain in patients with chronic pain after whiplash has been determined as 54% to 60%. However, the prevalence of chronic cervical facet joint pain has not yet been determined in a heterogenous population or in patients with cervical spine pain of idiopathic origin in a controlled environment. This study evaluated 160 patients seen in one interventional pain management practice in a non-university setting. Cervical facet joints were investigated with diagnostic blocks using lidocaine 1% preservative free initially, followed by bupivacaine 0.25%, usually 2 to 4 weeks apart. The study population consisted of 76 women and 30 men aged 43 +/- 13 years of age (mean +/- SD). Mode of onset of neck pain was determined as following a traumatic incident in 48% of the patients, whereas it was with gradual onset without an identifiable specific incident in the remaining 55 patients (52%). Eighty-one or 70% of the patients (70%) reported a definite response to lidocaine blocks. Confirmatory blocks with bupivacaine were performed in 81 patients with 64 patients with 60% of the total sample, or 79%, of the lidocaine-positive group reporting definite response with improvement in their pain. Thus, a prevalence rate of facet joint pain in chronic neck pain was determined to be 60% (95% CI, 50%-70%), with a false positive rate of controlled diagnostic blocks of 40% (95% CI, 34%-46%).

  15. Sensory and sympathetic innervation of cervical facet joint in rats

    Institute of Scientific and Technical Information of China (English)

    ZHOU Hai-yu; CHEN An-min; GUO Feng-jing; LIAO Guang-jun; XIAO Wei-dong

    2006-01-01

    Objective: To explore the patterns of innervation of cervical facet joints and determine the pathways from facet joints to dorsal root ganglions (DRGs) in order to clarify the causes of diffuse neck pain, headache, and shoulder pain.Methods: Forty-two male Sprague-Dawley rats,weighing 250-300 g, were randomly divided into three groups: Group A ( n = 18), Group B ( n = 18), and Group C (n = 6 ). Under anesthesia with intraperitoneal pentobarbital sodium (45 mg/kg body weight), a midline dorsal longitudinal incision was made over the cervical spine to expose the left cervical facet joint capsule of all the rats under a microscope. The rats in Group A underwent sympathectomy, but the rats in Group B and Group C did not undergo sympathectomy. Then 0.6 μl 5 % bisbenzimide (Bb) were injected into the C1-2, C3-4 and C5-6 facet joints of 6 rats respectively in Group A and Group B. The holes were immediately sealed with mineral wax to prevent leakage of Bb and the fascia and skin were closed. But in Group C, 0.9% normal saline was injected into the corresponding joint capsules. Then under deep reanesthesia with intraperitoneal pentobarbital sodium (45 mg/kg body weight), C1-C8 left DRGs in all rats and the sympathetic ganglions in Group B were obtained and the number of the labeled neurons was determined.Results: Neurons labeled with Bb were present in C1-C8 DRGs in both Group A and Group B, and sympathetic ganglions in Group B. In the C1-2 and C3-4 subgroups,labeled neurons were present from C1 to C8 DRGs, while in C5-6 subgroups they were from C, to C8. The number of Bb ( + ) neurons after sympathectomy was not significantly different in the injected level from that without sympathectomy. But in the other levels, the number of Bb ( + ) neurons after sympathectomy was significantly less than that without sympathectomy.Conclusions: The innervation of the cervical facet joints is derived from both sensory and sympathetic nervous system, and DRGs are associated with

  16. Simple facet joint repair with dynamic pedicular system: Technical note and case series

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    Ali Fahir Ozer

    2015-01-01

    Full Text Available Purpose: Facet joints are important anatomical structures for the stability of spine. Surgical or degenerative damage to a facet joint may lead to spinal instability and causes clinical problems. This article explains the importance of facet joints, reviews facet replacement systems, and describes a simple and effective method for facet replacement after surgical removal of facet joints. Materials and Methods: Ten patients were operated with the diagnosis of unilateral nerve root compression secondary to facet degeneration. The hypertrophic facet joints were removed with microsurgical techniques and the roots were decompressed. Then, a unilateral artificial facet joint was created using two hinged screws and a dynamic rod. Results: The clinical outcome of all the patients was determined good or excellent at second and last follow-up (mean 13.3 months controls using visual analog scale (VAS and Oswestry Disability Index (ODI scores. Radiological evaluations also demonstrated no implant-related complications. Conclusions: The authors suggest that, if removal of a facet joint is necessary to decompress the nerve roots, the joint can be replaced by a construct composed of two hinged screws connected by a dynamic rod. This simple system mimics the function of a normal facet joint and is an effective technique for unilateral facet joint replacement.

  17. Facet joint laser radiation: tissue effects of a new clinical laser application

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    Werkmann, Klaus; Thal, Dietmar R.

    1996-01-01

    Chronic unilateral and bilateral back pain with pseudoradicular symptoms, is a common clinical syndrome, which in many cases can be related to the facet joint syndrome. The pain is caused by mechanical affection of synovial and capsular nerve terminals. Therefore, current therapeutical attempts including physical therapy, intra-articular injection of local anesthetics and steroids and thermocoagulation of the facet joint with a thermocoagulator, are performed. We confirmed laser coagulation of the facet joint. Porcine cadaveric spines were treated immediately after death by intra-articular facet joint laser radiation. With the pulsed Nd:YAG laser (1064 nm) altogether 600 J were applied in three different places 4 mm apart at the top of the facet joint. The results showed that facet joint laser radiation leads to a small (about 1 - 2 mm diameter) lesion restricted to the facet joint cavity and its synovia. Histologically, we found a central carbonization zone and necrosis, including almost the whole cartilage and approximately 0.2 mm of the adjacent bone. These changes are similar to Nd:Yag-laser applications in other skeletal regions. It is suggested that these changes may lead to facet joint denervation by coagulation of the synovial nerve terminals. Cicatration of the laser lesion might cause ankylosis of this joint. In sum, facet joint laser radiation could be an alternative therapeutical tool for lower back pain of the facet joint syndrome type. Therefore, future clinical application of this technique seems to be very promising.

  18. Utilization of Facet Joint and Sacroiliac Joint Interventions in Medicare Population from 2000 to 2014: Explosive Growth Continues!

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    Manchikanti, Laxmaiah; Hirsch, Joshua A; Pampati, Vidyasagar; Boswell, Mark V

    2016-10-01

    Increasing utilization of interventional techniques in managing chronic spinal pain, specifically facet joint interventions and sacroiliac joint injections, is a major concern of healthcare policy makers. We analyzed the patterns of utilization of facet and sacroiliac joint interventions in managing chronic spinal pain. The results showed significant increase of facet joint interventions and sacroiliac joint injections from 2000 to 2014 in Medicare FFS service beneficiaries. Overall, the Medicare population increased 35 %, whereas facet joint and sacroiliac joint interventions increased 313.3 % per 100,000 Medicare population with an annual increase of 10.7 %. While the increases were uniform from 2000 to 2014, there were some decreases noted for facet joint interventions in 2007, 2010, and 2013, whereas for sacroiliac joint injections, the decreases were noted in 2007 and 2013. The increases were for cervical and thoracic facet neurolysis at 911.5 % compared to lumbosacral facet neurolysis of 567.8 %, 362.9 % of cervical and thoracic facet joint blocks, 316.9 % of sacroiliac joints injections, and finally 227.3 % of lumbosacral facet joint blocks.

  19. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas, E-mail: amorettinicolas@yahoo.fr; Gallo, Giacomo, E-mail: giacomo.gallo83@gmail.com; Bertrand, Anne-Sophie, E-mail: asbertrand3@hotmail.com [Centre Hospitalier Universitaire de Nice (France); Bard, Robert L., E-mail: rbard@cancerscan.com [New York Medical College (United States); Kelekis, Alexis, E-mail: akelekis@med.uoa.gr [University General Hospital “ATTIKON” (Greece)

    2016-01-15

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4–L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  20. Percutaneous Facet Screw Fixation in the Treatment of Symptomatic Recurrent Lumbar Facet Joint Cyst: A New Technique.

    Science.gov (United States)

    Amoretti, Nicolas; Gallo, Giacomo; Bertrand, Anne-Sophie; Bard, Robert L; Kelekis, Alexis

    2016-01-01

    We present a case of percutaneous treatment of symptomatic recurrent lumbar facet joint cyst resistant to all medical treatments including facet joint steroid injection. Percutaneous transfacet fixation was then performed at L4-L5 level with a cannulated screw using CT and fluoroscopy guidance. The procedure time was 30 min. Using the visual analog scale (VAS), pain decreased from 9.5, preoperatively, to 0 after the procedure. At 6-month follow-up, an asymptomatic cystic recurrence was observed, which further reduced at the 1-year follow-up. Pain remained stable (VAS at 0) during all follow-ups. CT- and fluoroscopy-guided percutaneous cyst rupture associated with facet screw fixation could be an alternative to surgery in patients suffering from a symptomatic recurrent lumbar facet joint cyst.

  1. Joint Forces Capabilities

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    2007-11-02

    for countering the proliferation of weapons of mass destruction (WMD) in space. The Space Operations Center ( SPOC ), USSPACECOM is the single point...of contact for assessing space capabilities. Combatant commanders, subordinate JFCs, and Services can access this information from the SPOC via the...special operations forces SPOC Space Operations Center SSBN fleet ballistic missile submarine SST space support team UJTL Universal Joint Task List UN

  2. Factors affecting results of fluoroscopy-guided facet joint injection: Probable differences in the outcome of treatment between pure facet joint hypertrophy and concomitant diseases

    Directory of Open Access Journals (Sweden)

    Akif Albayrak

    2016-01-01

    Full Text Available Study Design: Retrospective cohort study. Purpose: Facet joints are considered a common source of chronic low-back pain. To determine whether pathogens related to the facet joint arthritis have any effect on treatment failure. Materials and Methods: Facet joint injection was applied to 94 patients treated at our hospital between 2011 and 2012 (mean age 59.5 years; 80 women and 14 men. For the purpose of analysis, the patients were divided into two groups. Patients who only had facet hypertrophy were placed in group A (47 patients, 41 women and 6 men, mean age 55.3 years and patients who had any additional major pathology to facet hypertrophy were placed in group B (47 patients, 39 women and 8 men, mean age 58.9 years. Injections were applied around the facet joint under surgical conditions utilizing fluoroscopy device guidance. A mixture of methylprednisolone and lidocaine was used as the injection ingredient. Results: In terms of Oswestry Disability Index (ODI and visual analog scale (VAS scores, no significant difference was found between preinjection and immediate postinjection values in both groups, and the scores of group A patients were significantly lower (P < 0.005 compared with that of group B patients at the end of the third, sixth, and twelfth month. Conclusion: For low-back pain caused by facet hypertrophy, steroid injection around the facet joint is an effective treatment, but if there is an existing major pathology, it is not as effective.

  3. Can extra-articular strains be used to measure facet contact forces in the lumbar spine? An in-vitro biomechanical study.

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    Zhu, Q A; Park, Y B; Sjovold, S G; Niosi, C A; Wilson, D C; Cripton, P A; Oxland, T R

    2008-02-01

    Experimental measurement of the load-bearing patterns of the facet joints in the lumbar spine remains a challenge, thereby limiting the assessment of facet joint function under various surgical conditions and the validation of computational models. The extra-articular strain (EAS) technique, a non-invasive measurement of the contact load, has been used for unilateral facet joints but does not incorporate strain coupling, i.e. ipsilateral EASs due to forces on the contralateral facet joint. The objectives of the present study were to establish a bilateral model for facet contact force measurement using the EAS technique and to determine its effectiveness in measuring these facet joint contact forces during three-dimensional flexibility tests in the lumbar spine. Specific goals were to assess the accuracy and repeatability of the technique and to assess the effect of soft-tissue artefacts. In the accuracy and repeatability tests, ten uniaxial strain gauges were bonded to the external surface of the inferior facets of L3 of ten fresh lumbar spine specimens. Two pressure-sensitive sensors (Tekscan) were inserted into the joints after the capsules were cut. Facet contact forces were measured with the EAS and Tekscan techniques for each specimen in flexion, extension, axial rotation, and lateral bending under a +/- 7.5 N m pure moment. Four of the ten specimens were tested five times in axial rotation and extension for repeatability. These same specimens were disarticulated and known forces were applied across the facet joint using a manual probe (direct accuracy) and a materials-testing system (disarticulated accuracy). In soft-tissue artefact tests, a separate set of six lumbar spine specimens was used to document the virtual facet joint contact forces during a flexibility test following removal of the superior facet processes. Linear strain coupling was observed in all specimens. The average peak facet joint contact forces during flexibility testing was greatest in

  4. Association between facet joint osteoarthritis and the Oswestry Disability Index

    Institute of Scientific and Technical Information of China (English)

    Adel; Maataoui; Thomas; J; Vogl; Marcus; Middendorp; Konstantinos; Kafchitsas; M; Fawad; Khan

    2014-01-01

    AIM:To investigate the correlation of facet joint osteoarthritis(FJOA) at lumbar levels L4/L5 and L5/S1 and the Oswestry Disability Index(ODI).METHODS:The study involved lumbar MRIs of 591 patients with a mean age of 47.3 years.The MRIs of the lumbar spine were performed on a 1.5 Tesla scanner(Magnetom Avanto,Siemens AG,Erlangen,Germany) using a dedicated receive only spine coil.After initial blinding,each dataset was evaluated by 2 board certified radiologist with more than 5 years experience in musculoskeletal imaging.In total 2364 facet joints were graded.Degenerative changes of the facet joints were evaluated according to the 4-point scale as proposed by Weishaupt et al Functional status was assessed using the ODI.The index is scored from 0 to 100 and interpreted as follows:0%-20%,minimaldisability; 20%-40%,moderate disability; 40%-60%,severe disability; 60%-80%,crippled; 80%-100%,patients are bedbound.Spearman’s coefficient of rank correlation was used for statistical analysis,with significance set at P < 0.05.RESULTS:In total 2364 facet joints at lumbar levels L4/5 and L5/S1 were analysed in 591 individuals.FJOA was present in 97%(L4/L5) and 98%(L5/S1).At level L4/5(left/right) 17/15(2.9%/2.5%) were described as grade 0,146/147(24.7%/24.9%) as grade 1,290/302(49.1%/51.1%) as grade 2 and 138/127(23.4%/21.5%) as grade 3.At level L5/S1(left/right) 10/11(1.7%/1.9%) were described as grade 0,136/136(23.0%/23.0%) as grade 1,318/325(53.8%/55.0%) as grade 2 and 127/119(21.5%/20.1%) as grade 3.Regarding the ODI scores,patients’ disability had a minimum of 0% and a maximum of 91.11% with an arithmetic mean of 32.77% ± 17.02%.The majority of patients(48.39%) had moderate functional disability(21%-40%).There was no significant correlation between FJOA and ODI on both sides of lumbar level L4/5 and on the left side of lumbar level L5/S1.A weak positive correlation was evaluated between ODI and FJOA on the right side of lumbar level L5/S1.CONCLUSION:The missing

  5. Facet joint injuries in acute cervical spine trauma : evaluation with CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Jeon Ju; Kim, Dong Hyun; Lee, Jeong Hwa; Lee, Keon; Kwon, Hyeok Po; Kwon, Jung Hyeok; Yun, Seong Mun [Dongkang General Hospital, Seoul (Korea, Republic of)

    1999-05-01

    To evaluate injury patterns of facet joints and associated soft tissue injuries in patients with acute traumatic cervical facet joint injuries. From among patients with cervical spine trauma, 27 with facet joint injuries, as seen on CT and MRI, were chosen for this study. CT scans were analyzed with regard to the location of facet joint injury, the presence or absence of facet dislocation or fracture, and other associated fractures. MR images were analyzed with regard to ligament injury, intervertebral disc injury, intervertebral disc herniation, and spinal cord injury. The most common location of facet joint injury was C6-7 level(n=10), followed by C5-6(n=8). Among these 27 patients with facet joint injuries, 12(44%) had bilateral injuries and 15(56%) unilateral injuries. Facet fractures were present in 17 cases(63%) and the fracture of inferior facet was more frequent than superior. Patterns of fracture were vertical, transverse, or comminuted, but vertical fracture was the most common. Various degrees of dislocation were observed in patients with facet fractures. Fractures other than facet included pillar(n=11), lamina(n=6), transverse process(n=14), body(n=13), and spinous process(n=3). On MR images, anterior longitudinal ligament injury was found in 8 patients(30%), posterior longitudinal ligament injury in 4(15%), and interspinous ligament injury in 20(74%). Twelve patients(44%) had spinal cord injuries including edema(n=8) and hemorrhage(n=4). Among patients with disc abnormalities, 11(41%) had intervertebral disc injuries, and traumatic disc herniations were found in nine. Traumatic cervical facet joint injuries were manifested as various patterns and frequently associated with other fractures or soft tissue injuries. Analysis of CT and MR findings of these injury patterns helped formulate a therapeutic plan and determine of prognosis.

  6. The Interface of Mechanics and Nociception in Joint Pathophysiology: Insights From the Facet and Temporomandibular Joints.

    Science.gov (United States)

    Sperry, Megan M; Ita, Meagan E; Kartha, Sonia; Zhang, Sijia; Yu, Ya-Hsin; Winkelstein, Beth

    2017-02-01

    Chronic joint pain is a widespread problem that frequently occurs with aging and trauma. Pain occurs most often in synovial joints, the body's load bearing joints. The mechanical and molecular mechanisms contributing to synovial joint pain are reviewed using two examples, the cervical spinal facet joints and the temporomandibular joint (TMJ). Although much work has focused on the macroscale mechanics of joints in health and disease, the combined influence of tissue mechanics, molecular processes, and nociception in joint pain has only recently become a focus. Trauma and repeated loading can induce structural and biochemical changes in joints, altering their microenvironment and modifying the biomechanics of their constitutive tissues, which themselves are innervated. Peripheral pain sensors can become activated in response to changes in the joint microenvironment and relay pain signals to the spinal cord and brain where pain is processed and perceived. In some cases, pain circuitry is permanently changed, which may be a potential mechanism for sustained joint pain. However, it is most likely that alterations in both the joint microenvironment and the central nervous system (CNS) contribute to chronic pain. As such, the challenge of treating joint pain and degeneration is temporally and spatially complicated. This review summarizes anatomy, physiology, and pathophysiology of these joints and the sensory pain relays. Pain pathways are postulated to be sensitized by many factors, including degeneration and biochemical priming, with effects on thresholds for mechanical injury and/or dysfunction. Initiators of joint pain are discussed in the context of clinical challenges including the diagnosis and treatment of pain.

  7. Detailed examination of the lower cervical spine facet joints in a road traffic crash fatality - a case study

    DEFF Research Database (Denmark)

    Uhrenholt, Lars; Nielsen, Edith; Vesterby, Annie

    2005-01-01

    The lower cervical spine facet joints of a road traffic crash fatality were examined using diagnostic imaging and histological techniques. No injuries to the cervical spine facet joints could be identified with diagnostic imaging including conventional radiology, CT and MRI. Examination of stained...... histological sections visualised the morphology and integrity of the facet joints in detail. Occult injuries to and in close proximity of the cervical spine facet joints were identified only on histological examination....

  8. Detailed examination of the lower cervical spine facet joints in a road traffic crash fatality - a case study

    DEFF Research Database (Denmark)

    Uhrenholt, Lars; Nielsen, Edith; Vesterby, Annie

    2005-01-01

    The lower cervical spine facet joints of a road traffic crash fatality were examined using diagnostic imaging and histological techniques. No injuries to the cervical spine facet joints could be identified with diagnostic imaging including conventional radiology, CT and MRI. Examination of stained...... histological sections visualised the morphology and integrity of the facet joints in detail. Occult injuries to and in close proximity of the cervical spine facet joints were identified only on histological examination....

  9. Subdural empyema following lumbar facet joint injection: An exceeding rare complication.

    Science.gov (United States)

    Fayeye, Oluwafikayo; Silva, Adikarige Haritha Dulanka; Chavda, Swarupsinh; Furtado, Navin Raoul

    2016-01-01

    Chronic low back pain is extremely common with a life time prevalence estimated at greater than 70%. Facet joint arthrosis is thought to be the causative aetiological substrate in approximately 25% of chronic low back pain cases. Facet joint injection is a routine intervention in the armamentarium for both the diagnostic and therapeutic management of chronic low back pain. In fact, a study by Carrino et al. reported in excess of 94,000 facet joint injection procedures were carried out in the US in 1999. Although generally considered safe, the procedure is not entirely without risk. Complications including bleeding, infection, exacerbation of pain, dural puncture headache, and pneumothorax have been described. We report a rare case of a 47-year-old female patient who developed a left L4/5 facet septic arthrosis with an associated subdural empyema and meningitis following facet joint injection. This case is unique, as to the best of our knowledge no other case of subdural empyema following facet joint injection has been reported in the literature. Furthermore this case serves to highlight the potential serious adverse sequelae of a routine and apparently innocuous intervention. The need for medical practitioners to be alert to and respond rapidly to the infective complications of facet joint injection cannot be understated.

  10. Desmoid Type Fibromatosis in the Facet Joint of Lumbar Spine: Case Report and Review of Literature

    Science.gov (United States)

    Kim, So Jung; Lee, Sang Min; Kang, Haeyoun

    2013-01-01

    Desmoid type fibromatosis is a benign fibroblastic tumor arising from the fascia or musculoaponeurosis. It may occur in various locations, but most commonly in the shoulder girdle and neck; to our knowledge, there has been no reported case originating from a facet joint of the spine. We report CT and MR imaging findings of a desmoid type fibromatosis, involving the facet joint of the L3-4 spine with bone involvement. PMID:24043979

  11. Neuronal hyperexcitability in the dorsal horn after painful facet joint injury

    OpenAIRE

    2010-01-01

    Excessive cervical facet capsular ligament stretch has been implicated as a cause of whiplash-associated disorders following rear-end impacts, but the pathophysiological mechanisms that produce chronic pain in these cases remain unclear. Using a rat model of C6/C7 cervical facet joint capsule stretch that produces sustained mechanical hyperalgesia, the presence of neuronal hyperexcitability was characterized 7 days after joint loading. Extracellular recordings of spinal dorsal horn neuronal a...

  12. Simple facet joint repair with dynamic pedicular system: Technical note and case series

    OpenAIRE

    Ali Fahir Ozer; Tuncer Suzer; Mehdi Sasani; Tunc Oktenoglu; Phillip Cezayirli; Hosein Jafari Marandi; Deniz Ufuk Erbulut

    2015-01-01

    Simple facet joint repair with dynamic pedicular system: Technical note and case series Ali Ozer, Tuncer Suzer, Mehdi Sasani, Tunc Oktenoglu, Phillip Cezayirli and Hosein Marandi Journal of Craniovertebral Junction and Spine. 6.2 (April-June 2015): p65. Copyright: COPYRIGHT 2015 Medknow Publications and Media Pvt. Ltd. http://www.jcvjs.com/ Full Text: Byline: Ali. Ozer, Tuncer. Suzer, Mehdi. Sasani, Tunc. Oktenoglu, Phillip. Cezayirli, Hosein. Marandi, Deniz. Erbulut Purpose: Facet joints are...

  13. Desmoid type fibromatosis in the facet joint of lumbar spine: Case report and review of literature

    Energy Technology Data Exchange (ETDEWEB)

    Kim, So Jung; Ha, Doo Hoe; Lee, Sang Min; Kang, Hae Youn [CHA Bundang Medical Center, CHA University, Seongnam (Korea, Republic of)

    2013-10-15

    Desmoid type fibromatosis is a benign fibroblastic tumor arising from the fascia or musculoaponeurosis. It may occur in various locations, but most commonly in the shoulder girdle and neck; to our knowledge, there has been no reported case originating from a facet joint of the spine. We report CT and MR imaging findings of a desmoid type fibromatosis, involving the facet joint of the L3-4 spine with bone involvement.

  14. Finite element lumbar spine facet contact parameter predictions are affected by the cartilage thickness distribution and initial joint gap size.

    Science.gov (United States)

    Woldtvedt, Daniel J; Womack, Wesley; Gadomski, Benjamin C; Schuldt, Dieter; Puttlitz, Christian M

    2011-06-01

    Current finite element modeling techniques utilize geometrically inaccurate cartilage distribution representations in the lumbar spine. We hypothesize that this shortcoming severely limits the predictive fidelity of these simulations. Specifically, it is unclear how these anatomically inaccurate cartilage representations alter range of motion and facet contact predictions. In the current study, cadaveric vertebrae were serially sectioned, and images were taken of each slice in order to identify the osteochondral interface and the articulating surface. A series of custom-written algorithms were utilized in order to quantify each facet joint's three-dimensional cartilage distribution using a previously developed methodology. These vertebrae-dependent thickness cartilage distributions were implemented on an L1 through L5 lumbar spine finite element model. Moments were applied in three principal planes of motion, and range of motion and facet contact predictions from the variable thickness and constant thickness distribution models were determined. Initial facet gap thickness dimensions were also parameterized. The data indicate that the mean and maximum cartilage thickness increased inferiorly from L1 to L5, with an overall mean thickness value of 0.57 mm. Cartilage distribution and initial facet joint gap thickness had little influence on the lumbar range of motion in any direction, whereas the mean contact pressure, total contact force, and total contact area predictions were altered considerably. The data indicate that range of motion predictions alone are insufficient to establish model validation intended to predict mechanical contact parameters. These data also emphasize the need for the careful consideration of the initial facet joint gap thickness with respect to the spinal condition being studied.

  15. Septic arthritis in a lumbar facet joint: a rare cause of an epidural abscess

    Energy Technology Data Exchange (ETDEWEB)

    Heenan, S.D. [Dept. of Neuroradiology, Atkinson Morley`s Hospital, London (United Kingdom); Britton, J. [Dept. of Neuroradiology, Atkinson Morley`s Hospital, London (United Kingdom)

    1995-08-01

    A 10-year-old boy presented with a 7-day history of back pain and pyrexia. MRI showed an epidural abscess arising from septic arthritis in a lumbar facet joint. To our knowledge, there are only two previously reported cases of septic arthritis of a facet joint leading to an epidural abscess. This case illustrates how infection in a synovial joint may extend into the extradural space and might be the route of infection in more cases than has previously been recognised. (orig.)

  16. Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.L.; Kaplan, P.A.; Dussault, R.G.; Anderson, M.W. [Dept. of Radiology, Univ. of Virginia Health System, Charlottesville, VA (United States)

    2000-12-01

    Objective. Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.Design. Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.Conclusions. Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment. (orig.)

  17. Pressure measurement in the cervical spinal facet joint: considerations for maintaining joint anatomy and an intact capsule.

    Science.gov (United States)

    Jaumard, Nicolas V; Bauman, Joel A; Welch, William C; Winkelstein, Beth A

    2011-07-01

    A novel noninvasive approach to measure facet joint pressure in the cervical spine was investigated using a tip-mounted transducer that can be inserted through a hole in the bony lateral mass. This technique is advantageous because it does not require resection of the joint capsule, but there are potential issues regarding its applicability that are addressed. The objective was to evaluate the effect of a tip-mounted pressure probe's position and orientation on contact pressure measurements in biomechanical experiments. Measurements of direct contact pressure in the facet joint of cadaveric spines have been obtained via pressure-sensitive films. However, that method requires the resection of the facet capsule, which can alter the overall joint's mechanical behavior and can affect the measured contact pressures. Influence of position and orientation on probe measurements was evaluated in companion surrogate and cadaveric investigations. The probe was placed in the facet of an anatomic vertebral C4/5 surrogate undergoing sagittal bending moments. Pressure-sensitive paper was used to map contact regions in the joint of the surrogate and cadaveric cervical segments (n = 3) during extension. The probe also underwent uniaxial compression in cadaveric facets to evaluate the effect of orientation relative to the contact surface on the probe signal. Although experimental and theoretical pressure profiles followed the same trends, measured maximum pressures were half of the theoretical ones. In the orientation study, maximum pressures were not different for probe orientations of 0° and 5°, but no signal was recorded at orientations greater than 15°. This approach to measure pressure was selected to provide a minimally-invasive method to quantify facet joint pressures during clinically relevant applications. Both the position and orientation of the probe are critical factors in monitoring local pressure profiles in this mobile synovial joint.

  18. The prevalence of lumbar facet joint edema in patients with low back pain

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, Klaus M.; Pinker, Katja; Trattnig, Siegfried [Medical University of Vienna, Division of MSK, Department of Radiology, Center of Excellence for High Field MRI, Vienna (Austria); Nemec, Stefan; Peloschek, Philipp; Weber, Michael [Medical University of Vienna, Division of MSK, Department of Radiology, Vienna (Austria)

    2007-08-15

    The objective was to assess the prevalence of lumbar facet joint edema in patients with low back pain. Lumbar spine MR examinations (1.5 T) of 145 consecutive patients (87 women, 58 men; mean age 52.8, range 17-94 years) were retrospectively evaluated with regard to the presence of facet joint edema. The MR protocol included sagittal short-tau inversion recovery (STIR), T1- and T2-weighted as well as transverse T2-weighted images. In 9 patients follow-up MR examinations were performed and results were compared with pain. The agreement between the change in intensity of facet joint edema and the change in intensity of pain was assessed using kappa statistics and Kendall's tau coefficient. In 21 of the 145 patients (14%) edema was found at the facet joints: in 52.4% at L4/5, in 19.0% at L5/S1, in 14.3% at L4/5 and L5/S1, in 9.5% at L3/4 and L4/5, and in 4.8% at L3/4. The agreement between the change in pain score and intensity of edema within the follow-up group was ''almost perfect'' (kappa = 0.81). Kendall's tau coefficient was 0.91, indicating high agreement. Sagittal STIR images detect facet joint edema in 14% of patients with low back pain. This fact may be useful for planning treatment including facet joint injections. (orig.)

  19. Prevalence of facet joint pain in chronic spinal pain of cervical, thoracic, and lumbar regions

    Directory of Open Access Journals (Sweden)

    Pampati Vidyasagar

    2004-05-01

    Full Text Available Abstract Background Facet joints are a clinically important source of chronic cervical, thoracic, and lumbar spine pain. The purpose of this study was to systematically evaluate the prevalence of facet joint pain by spinal region in patients with chronic spine pain referred to an interventional pain management practice. Methods Five hundred consecutive patients with chronic, non-specific spine pain were evaluated. The prevalence of facet joint pain was determined using controlled comparative local anesthetic blocks (1% lidocaine or 1% lidocaine followed by 0.25% bupivacaine, in accordance with the criteria established by the International Association for the Study of Pain (IASP. The study was performed in the United States in a non-university based ambulatory interventional pain management setting. Results The prevalence of facet joint pain in patients with chronic cervical spine pain was 55% 5(95% CI, 49% – 61%, with thoracic spine pain was 42% (95% CI, 30% – 53%, and in with lumbar spine pain was 31% (95% CI, 27% – 36%. The false-positive rate with single blocks with lidocaine was 63% (95% CI, 54% – 72% in the cervical spine, 55% (95% CI, 39% – 78% in the thoracic spine, and 27% (95% CI, 22% – 32% in the lumbar spine. Conclusion This study demonstrated that in an interventional pain management setting, facet joints are clinically important spinal pain generators in a significant proportion of patients with chronic spinal pain. Because these patients typically have failed conservative management, including physical therapy, chiropractic treatment and analgesics, they may benefit from specific interventions designed to manage facet joint pain.

  20. [CORRELATION OF LUMBAR FACET JOINT DEGENERATION AND SPINE-PELVIC SAGITTAL BALANCE].

    Science.gov (United States)

    Lo, Xin; Zhang, Bin; Liu, Yuan; Dai, Min

    2015-08-01

    To investigate the relationship between lumbar facet joint degeneration of each segment and spine-pelvic sagittal balance parameters. A retrospective analysis was made the clinical data of 120 patients with lumbar degenerative disease, who accorded with the inclusion criteria between June and November 2014. There were 58 males and 62 females with an average age of 53 years (range, 24-77 years). The disease duration ranged from 3 to 96 months (mean, 6.6 months). Affected segments included L3,4 in 32 cases, L4,5 in 47 cases, and L5, S1 in 52 cases. The CT and X-ray films of the lumbar vertebrae were taken. The facet joint degeneration was graded based on the grading system of Pathria. The spine-pelvic sagittal balance parameters were measured, including lumbar lordosis (LL), upper lumbar lordosis (ULL), lower lumbar lordosis (LLL), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS). According to normal range of PI, the patients were divided into 3 groups: group A (PI was less than normal range), group B (PI was within normal range), and group C (PI was more than normal range). The facet joint degeneration was compared; according to the facet joint degeneration degree, the patients were divided into group N (mild degeneration group) and group M (serious degeneration group) to observe the relationship of lumbar facet joint degeneration of each segment and spine-pelvic sagittal balance parameters. At L4,5 and L5, S1, facet joint degeneration showed significant difference among groups A, B, and C (P 0.05). There was no significant difference in the other spine-pelvic sagittal balance parameters between groups N and M at each segment (P > 0.05) except for PT (P spine.

  1. Ultrasound-guided facet joint injection to treat a spinal cyst

    Directory of Open Access Journals (Sweden)

    Tung-Liang Lin

    2014-04-01

    Full Text Available Lumbar spinal cysts often present with backache and may be accompanied by lower extremity weakness as well as radiation pain if root compression occurs. The treatment regimens include anti-inflammatory drugs, physical therapy, procedures guided by fluoroscopy or computed tomography, and surgery. We report the case of a patient with a symptomatic lumbar spinal cyst at the L4–L5 facet joint. The symptoms immediately remitted after ultrasound-guided steroid–lidocaine injection into the L4–L5 facet joint. Magnetic resonance imaging follow up 4 months after injection showed complete resolution of the cyst.

  2. Osteochondroma arising from a lumbar facet joint in a 16-year-old.

    Science.gov (United States)

    Hancock, Graeme E; Mariathas, Chrishan; Fernandes, James A; Breakwell, Lee M; Cole, Ashley A; Michael, Antony L R

    2015-05-01

    Osteochondromas are benign tumours of bony or cartilaginous origin, which may be solitary or multiple. They are rare in the axial skeleton and have previously been reported to arise from facet joints only in four cases in the English literature. We report the case of a 16-year-old girl who presented with a palpable bony lump and a short history of back pain. Imaging showed a bony lesion arising from a left-sided facet joint in the lumbar spine. Following excision biopsy, there was complete resolution of symptoms. The literature on the origin and management of spinal osteochondromas is discussed.

  3. Delayed onset of a spinal epidural hematoma after facet joint injection

    Directory of Open Access Journals (Sweden)

    Mirko Velickovic

    2016-10-01

    Full Text Available The treatment of chronic back pain is a challenging problem. Facet joint infiltration is an established treatment for chronic low back pain caused by arthrosis of the lumbar facet joints. Due to the increasing number of patients with chronic low back pain, this therapy has become more frequent. We treated a 51-year-old male patient, who developed an epidural hematoma 2 months after infiltration therapy. Our case shows that even a delayed onset of spinal epidural hematoma is possible and should be kept in mind as a possible cause of acute myelopathy after spinal intervention.

  4. MR imaging of lumbar facet joint synovial cysts

    Energy Technology Data Exchange (ETDEWEB)

    Apostolaki, E.; Davies, A.M.; Evans, N. [Royal Orthopaedic Hospital, Birmingham (United Kingdom). Dept. of Radiology; Cassar-Pullicino, V.N. [Robert Jones and Agnes Hunt Orthopaedic Hospital, Oswestry (United Kingdom)

    2000-04-01

    The increasing application of magnetic resonance (MR) imaging of the spine has raised the awareness of lumbar facet synovial cysts (LFSC). This well recognised, yet uncommon condition, presents with low back pain and radiculopathy due to the presence of an extradural mass. The commonest affected level is L4/5 with a mild degenerative spondylolisthesis a frequent associated finding. MR imaging is the technique of choice to detect and diagnose a LFSC. This pictorial essay, drawing on experience of 43 cases seen in 40 patients, illustrates the spectrum of appearances that can be encountered and suggest differing causes for the variable signal characteristics exhibited. Computed tomography (CT) can be of value in some cases to aid interpretation of the MR images. In addition, CT facet arthrography by injection of air or iodinated non-ionic contrast medium may be used to confirm the diagnosis in doubtful cases as well as noting whether the patients presenting symptoms can be provoked. A comprehensive review of the existing literature is presented. (orig.)

  5. Quantitative in vivo MRI evaluation of lumbar facet joints and intervertebral discs using axial T2 mapping

    Energy Technology Data Exchange (ETDEWEB)

    Stelzeneder, David; Messner, Alina; Scheurecker, Georg; Goed, Sabine; Friedrich, Klaus M.; Trattnig, Siegfried [Medical University of Vienna, Department of Radiology, MR Centre-High Field MR, Vienna (Austria); Vlychou, Marianna [Medical University of Vienna, Department of Radiology, MR Centre-High Field MR, Vienna (Austria); University Hospital of Larissa, Department of Radiology, Larissa (Greece); Welsch, Goetz H. [Medical University of Vienna, Department of Radiology, MR Centre-High Field MR, Vienna (Austria); University of Erlangen, Department of Trauma Surgery, Erlangen (Germany); Pieber, Karin; Pflueger, Verena [Medical University of Vienna, Department of Physical Medicine and Rehabilitation, Vienna (Austria)

    2011-11-15

    To assess the feasibility of T2 mapping of lumbar facet joints and intervertebral discs in a single imaging slab and to compare the findings with morphological grading. Sixty lumbar spine segments from 10 low back pain patients and 5 healthy volunteers were examined by axial T2 mapping and morphological MRI at 3.0 Tesla. Regions of interest were drawn on a single slice for the facet joints and the intervertebral discs (nucleus pulposus, anterior and posterior annulus fibrosus). The Weishaupt grading was used for facet joints and the Pfirrmann score was used for morphological disc grading (''normal'' vs. ''abnormal'' discs). The inter-rater agreement was excellent for the facet joint T2 evaluation (r = 0.85), but poor for the morphological Weishaupt grading (kappa = 0.15). The preliminary results show similar facet joint T2 values in segments with normal and abnormal Pfirrmann scores. There was no difference in mean T2 values between facet joints in different Weishaupt grading groups. Facet joint T2 values showed a weak correlation with T2 values of the posterior annulus (r = 0.32) This study demonstrates the feasibility of a combined T2 mapping approach for the facet joints and intervertebral discs using a single axial slab. (orig.)

  6. Septic arthritis of a lumbar facet joint; Arthrite septique interapophysaire posterieure lombaire

    Energy Technology Data Exchange (ETDEWEB)

    Ben Hamouda, M.; Rajhi, H.; Golli, M.; Ganouni, A.; Bergaoui, N. [Centre Hospitalier Universitaire de Monastir (Tunisia); Chaouch, A. [Centre Hospitalier Universitaire de Mahdia (Tunisia); Hassine, H. [Centre Hospitalier Universitaire de Sahloul, Sousse (Tunisia)

    1997-05-01

    Septic arthritis of the posterior lumbar joints is extremely rare. The clinical picture of the unusual site of infection can easily lead to confusion with spondylo-discitis which is more common. We report a case of a 50-year-old women with Staphylococcus aureus septic arthritis of the left L5-S1 lumbar facet joint. CT scan was helpful to establish the diagnosis and to guide the percutaneous needle biopsy. (authors). 10 refs.

  7. Talocalcaneal Joint Middle Facet Coalition Resection With Interposition of a Juvenile Hyaline Cartilage Graft.

    Science.gov (United States)

    Tower, Dyane E; Wood, Ryan W; Vaardahl, Michael D

    2015-01-01

    Talocalcaneal joint middle facet coalition is the most common tarsal coalition, occurring in ≤2% of the population. Fewer than 50% of involved feet obtain lasting relief of symptoms after nonoperative treatment, and surgical intervention is commonly used to relieve symptoms, increase the range of motion, improve function, reconstruct concomitant pes planovalgus, and prevent future arthrosis from occurring at the surrounding joints. Several approaches to surgical intervention are available for patients with middle facet coalitions, ranging from resection to hindfoot arthrodesis. We present a series of 4 cases, in 3 adolescent patients, of talocalcaneal joint middle facet coalition resection with interposition of a particulate juvenile hyaline cartilaginous allograft (DeNovo(®) NT Natural Tissue Graft, Zimmer, Inc., Warsaw, IN). With a mean follow-up period of 42.8 ± 2.9 (range 41 to 47) months, the 3 adolescent patients in the present series were doing well with improved subtalar joint motion and decreased pain, and 1 foot showed no bony regrowth on a follow-up computed tomography scan. The use of a particulate juvenile hyaline cartilaginous allograft as interposition material after talocalcaneal middle facet coalition resection combined with adjunct procedures to address concomitant pes planovalgus resulted in good short-term outcomes in 4 feet in 3 adolescent patients. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  8. Severe Facet Joint Arthrosis Caused C7/T1 Myelopathy: A Case Report

    Directory of Open Access Journals (Sweden)

    Toshimi Aizawa

    2009-01-01

    Full Text Available Cervical myelopathy is caused by degenerative processes of the spine including intervertebral disc herniation and posterior spur usually developing at C3/4 to C5/6. C7/T1 single level myelopathy is very rare because of the anatomical characteristics. Facet joint arthrosis can be a cause of cervical myelopathy but only a few cases have been reported. The authors report an extremely rare case of C7/T1 myelopathy caused by facet joint arthrosis. A 58-year-old male presented with hand and gait clumsiness. The radiological examinations revealed severe C7/T1 facet joint arthrosis with bony spur extending into the spinal canal, which compressed the spinal cord laterally. The T1 spinous process indicated nonunion of a “clay-shoveler's” fracture, which suggested that his cervico-thoracic spine had been frequently moved, and thus severe arthrosis had occurred in the facet joints. A right hemilaminectomy of C7 and C7/T1 facetectomy with single level spinal fusion led to complete neurological improvement.

  9. Arthrofibrosis involving the middle facet of the talocalcaneal joint in children and adolescents.

    Science.gov (United States)

    El Rassi, George; Riddle, Eric C; Kumar, S Jay

    2005-10-01

    Pain over the anterolateral aspect of the ankle in a patient with a history of repeated ankle sprains and with restricted subtalar movement may be associated with a tarsal coalition. Nineteen patients presented with such a history, but conventional imaging did not reveal a cartilaginous or osseous coalition. Since symptoms persisted despite nonoperative treatment, the middle facet was explored surgically. The purpose of this study was to discuss the operative findings and to report the results of treatment. Nineteen patients (twenty-three feet) with pain over the anterolateral aspect of the ankle or a history of repeated ankle sprains had restricted subtalar joint motion and inconclusive findings on diagnostic imaging, except for bone-scanning. Their ages ranged from 9.1 to 18.5 years. The middle facet of the subtalar joint was explored surgically through a 3 to 4-cm-long incision centered over the sustentaculum tali. The results at a mean of 5.8 years were classified as good, fair, or poor on the basis of pain, talocalcaneal joint motion, and shoe wear. Routine radiographs, computed tomography, and magnetic resonance imaging revealed no major abnormality, whereas technetium-99m bone scintigraphy consistently showed slightly increased isotope uptake in the middle facet. Surgical removal of a hypervascular and thickened capsule and synovium in the area of the middle facet of the subtalar joint decreased pain and improved subtalar motion. The final result was good in seventeen patients (twenty feet) and fair in two patients (three feet). There were no poor results. A diagnosis of inflammatory arthrofibrosis should be considered when a patient with a painful rigid flatfoot has normal findings on radiographs and hematological studies but increased isotope uptake in the middle facet of the talocalcaneal joint on bone scintigraphy. Excision of the hypervascular capsule and synovium from this area can result in resolution of the symptoms. Therapeutic Level IV.

  10. CHANGES FACETS JOINTS IN TRAUMA AND DEGENERATIVE DISEASES OF THE LUMBAR SPINE

    Directory of Open Access Journals (Sweden)

    V. V. Shchedrenok

    2011-01-01

    Full Text Available Produced spondilometric measurements of the lumbosacral spine is normal (20 cases and in patients with spinal cord injury and degenerative-dystrophic diseases of the spine (43 cases. The width of the facet joint space joints on both sides, its relation to the longitudinal axis of the body in degrees and another on the same level were studied. The width of the facet joint space at the lumbosacral level of 3.5–4.0 mm, the area of the intervertebral foramen varies from 96–132 mm2. Among the changes in the parameters of the vertebral-motor segment can distinguish moderate, marked and significant extent that is important in determining the amount of the alleged operation.

  11. Navigated Pin-Point Approach to Osteoid Osteoma Adjacent to the Facet Joint of Spine

    Science.gov (United States)

    Neo, Masashi; Takemoto, Mitsuru; Nishizawa, Kazuya; Imai, Shinji

    2016-01-01

    Osteoid osteoma (OO) is a benign osteoblastic tumor. Its curative treatment is complete removal of the nidus, where intraoperative localization of the nidus governs clinical results. However, treatment can be difficult since the lesion is often invisible over the bony surface. Accordingly, establishment of an ideal less invasive surgical strategy for spinal OO remains yet unsettled. We illustrate the efficacy of a computed tomography (CT)-based navigation system in excising OO located adjacent to the facet joint of spine. In our 2 cases, complete and pin-point removal of the nidus located close to the facet joint was successfully achieved, without excessive removal of the bone potentially leading to spinal instability and possible damage of nearby neurovascular structures. We advocate a less invasive approach to spinal OO, particularly in an environment with an available CT-based navigation system. PMID:26949472

  12. Evaluation of Facet Joint Arthrosis in Stenotic and Normal Lumbar Spines with MRI

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    Ebru Ozan

    2013-10-01

    Full Text Available Aim: To reveal the prevalence of lumbar facet joint arthrosis in normal and stenotic lumbar spines with magnetic resonance imaging. Material and Method: Study group consisted of 30 patients with complaints and findings of lower back pain, neurologic claudicatio and lumbar spinal stenosis detected at L3-4, L4-5 and/or L5-S1 with magnetic resonance imaging (cross section area of the dural sac

  13. Unusual case of paediatric septic arthritis of the lumbar facet joints due to Kingella kingae.

    Science.gov (United States)

    Le Hanneur, M; Vidal, C; Mallet, C; Mazda, K; Ilharreborde, B

    2016-11-01

    A 32-month-old boy presented with febrile limping that had developed over 6days, associated with right lumbosacral inflammatory swelling. Magnetic resonance imaging (MRI) showed joint effusion of the right L5-S1 zygapophyseal joint, complicated by destructive osteomyelitis of the L5 articular process and paraspinal abscess. Surgery was decided to evacuate the fluid accumulation and rule out differential diagnoses. The diagnosis of septic arthritis of the facet joint was confirmed intraoperatively; real-time quantitative PCR analysis identified Kingella kingae. This is the first substantiated paediatric case of zygapophyseal joint septic arthritis due to K. kingae. K. kingae is the most common pathogen responsible for invasive osteoarticular infection in children under 4years of age. Since empiric antibiotics are effective in early stages, physicians should consider the possibility of spinal infections due to K. kingae when a limping child under 4years of age presents with a fever.

  14. Lumbar facet joint septic arthritis presenting atypically as acute abdomen – A case report and review of the literature

    Directory of Open Access Journals (Sweden)

    Aysha Rajeev

    2016-01-01

    Conclusion: The atypical presentation of facet joint septic arthritis is one of the reasons why early diagnosis is elusive. Definitive diagnoses with MRI and bacterial culture as well as prolonged antibiotic therapy are recommended in this condition.

  15. Geometry of the articular facets of the lateral atlanto-axial joints in the case of occipitalization.

    Science.gov (United States)

    Ryniewicz, A M; Skrzat, J; Ryniewicz, A; Ryniewicz, W; Walocha, J

    2010-08-01

    This study investigates if atlanto-occipital fusion affects the size and geometrical configuration of the articular facets of the atlanto-axial joint. Morphometric analysis was performed on the male adult skull, the occipital bone of which is assimilated with the first cervical vertebrae (the atlas). The perimeter, Feret's diameter, surface area, and circularity of the inferior articular fa-cets were measured. However, we did not observe significant bilateral differences in size of the inferior articular facets of the assimilated atlas compared to normal first cervical vertebrae. Geometrical conformation of the articular facets of the atlas and axis was assessed using a coordinate measuring machine (PMM - 12106, Leitz). The results obtained from this machine indicated that the inferior articular facets of the assimilated atlas presented asymmetrical orientation compared to the normal anatomy of the atlas. Hence, in the case of occipitalization, the gap between the articulating facets of the atlas and the axis was measured to be greater than in the normal atlanto-axial joint. Computer assisted tomography was applied to visualise the anatomical relationship between the inferior articular facets of the assimilated atlas and the corresponding facets located on the axis. In this case, radiographic examination revealed that the bilaterally articulating facets (inferior and superior) showed disproportion in their adjustment within the lateral atlanto-axial joints. Thus, we concluded that the fusion of the atlas with the occipital bone altered the geometry of the inferior articular facets of the atlas and influenced the orientation of the superior articular facets of the axis.

  16. Septic arthritis of a lumbar facet joint: Detection with bone SPECT imaging

    Energy Technology Data Exchange (ETDEWEB)

    Swayne, L.C.; Dorsky, S.; Caruana, V.; Kaplan, I.L. (Morristown Memorial Hospital, NJ (USA))

    1989-08-01

    We present a rare case of septic arthritis of a lumbar facet joint with an associated epidural abscess resulting from Staphylococcus aureus. The infection was initially detected with planar bone scintigraphy and precisely localized with single photon emission computed tomography bone scintigraphy, despite an initially negative radiologic evaluation that included radiographs of the lumbar spine, lumbar myelography, and a postmyelography x-ray computed tomography scan. In the appropriate clinical setting, a bone scan demonstrating unilateral increased activity within the spine should raise the suspicion of inflammatory involvement of the posterior elements.

  17. Pseudomeningocele in communication with the facet joint: demonstration by computerized tomography-arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Ganiyusufoglu, Kursat; Ozturk, Cagatay; Sirvanci, Mustafa; Aksu, Neslihan; Hamzaoglu, Azmi [Florence Nightingale Hospital, Istanbul Bilim University, Istanbul Spine Center, Istanbul (Turkey)

    2008-08-15

    Pseudomeningocele is an uncommon but well-known complication of lumbar spine operations. Although it is mostly asymptomatic and managed conservatively in most cases, it is claimed as a causative factor of failed back surgery syndrome and requires surgery in some cases. Usually, its diagnosis is confidently done with imaging modalities such as magnetic resonance imaging, computed tomography and myelography. In this report, we describe a case of pseudomeningocele that communicated with a facet joint. The diagnostic approach for this unusual lesion and its probable causes are discussed. (orig.)

  18. Idiopathic septic arthritis of a lumbar facet joint associated with paraspinal abscess.

    Science.gov (United States)

    Kitova-John, Margarita Borislavova; Azim-Araghi, Ali; Sheikh, Faraz Tariq; Kitov, Borislav Dimitrov

    2015-08-13

    A 48-year-old woman presented with a 1-month history of severe lower back pain on a background of 24 h of mild fever and general tiredness with an associated right-sided foot drop. Five weeks after the onset and with no improvement in symptoms in spite of analgesia and physiotherapy, the patient had a lumbar spine MRI which demonstrated a collection extending from the facet joints of L5 and L6 to the iliacus muscle on the right. A CT-guided aspiration was performed with a lengthy hospital stay for intravenous antibiotic treatment. The culture and sensitivity study of the aspirate isolated Streptococcus pneumoniae.

  19. Does therapist’s attitude affect clinical outcome of lumbar facet joint injections?

    Institute of Scientific and Technical Information of China (English)

    Marcus Middendorp; Konstantinos Kollias; Hanns Ackermann; Annina Splettst??er; Thomas J Vogl; M Fawad Khan; Adel Maataoui

    2016-01-01

    AIM: To investigate if the clinical outcome of intraarticular lumbar facet joint injections is affected by the therapist’s attitude. METHODS: A total of 40 patients with facet jointassociated chronic low back pain were randomly divided into two groups. All patients received computed tomography-guided, monosegmental intra-articular facet joint injections. Following the therapeutic procedure, the patients of the experimental group(EG) held a conversation with the radiologist in a comfortable atmosphere. During the dialog, the patients were encouraged to ask questions and were shown four images. The patients of the control group(CG) left the clinic without any further contact with the radiologist. Outcome was assessed using a pain-based Verbal Numeric Scale at baseline, at 1 wk and at 1, 3, and 6 mo after first treatment. RESULTS: The patient demographics showed no differences between the groups. The patients of the EG received 57 interventional procedures in total, while the patients of the CG received 70 interventional procedures. In both groups, the pain scores decreased significantly over the entire observation period. Compared to the CG, the EG showed a statistically significant reduction of pain at 1 wk and 1 mo post-treatment, while at 3 and 6 mo after treatment, there were no significant differences between both groups. CONCLUSION: Our results show a significant effect on pain relief during the early post-interventional period in the EG as compared to the CG. The basic principle behind the higher efficacy might be the phenomenon of hetero-suggestion.

  20. Pigmented villonodular synovitis originating from the lumbar facet joint: a case report

    Science.gov (United States)

    Oe, Kenichi; Yoshida, Yugo; Ohnari, Hiroyuki; Iida, Hirokazu; Sakaida, Noriko; Uemura, Yoshiko

    2007-01-01

    The authors successfully treated a rare case of pigmented villonodular synovitis (PVNS) that originated from the lumbar facet joint (L4-5). A 43-year-old man presented with a complaint of left severe sciatica causing difficulty in walking. Magnetic resonance imaging (MRI) demonstrated an extradural mass on the left side at L4 and the mass compressed the dural tube and was continuous with the left L4-5 facet joint. A computed tomography myelogram revealed an extradural defect of contrast medium at the L4 level and an erosion of the L4 lamina. A total synovectomy with unilateral osteoplastic laminectomy was performed. The histological findings were a diagnosis of PVNS. The patient’s symptoms resolved completely and the MRI at postoperative 3 years demonstrated no recurrence of PVNS. It is important to totally remove the synovium, which is the origin of PVNS in order to prevent the recurrence. We think that our procedure is reasonable and adequate for lumbar PVNS. PMID:17566795

  1. The Variation in the Lumbar Facet Joint Orientation in an Adult Asian Population and Its Relationship with the Cross-Sectional Area of the Multifidus and Erector Spinae

    Science.gov (United States)

    Katayose, Masaki; Watanabe, Kota

    2016-01-01

    Study Design Cross-sectional study of healthy volunteers. Purpose We aimed to investigate the variation in the lumbar facet joint orientation in an adult Asian population. The relationship between the facet joint orientation and muscle cross-sectional area (CSA) of multifidus and erector spinae was also clarified. Overview of Literature Several studies have reported that lumbar pathologies, such as lumbar spondylolysis and degenerative spondylolisthesis, were related to the horizontally shaped lumbar facet joint orientation at the lower lumbar level. However, data regarding variations in the facet joint orientation in asymptomatic subjects have not been well documented. Methods In 31 healthy male adult Asian volunteers, the facet joint orientation and CSA of multifidus and erector spinae were measured using magnetic resonance imaging at the L4–5 and L5–S1 levels. Variation in the facet joint orientation was examined using coefficients of variation (CV). Pearson's product-moment coefficient was used to investigate the relationship between the facet joint orientation and CSA of multifidus and erector spinae. Results Lumbar facet joint orientation had a wider range of variation at L5–S1 (CV=0.30) than at L4–5 (CV=0.18). The L4–5 facet joint orientation had a weak but significant correlation with the CSA of erector spinae (r=0.40; p=0.031). The CSA of the multifidus had no relationship with the facet joint orientation at the L4–5 (r=0.19; p=0.314) and the L5–S1 level (r=0.19; p=0.312). Conclusions The lumbar facet joint orientation was found to have a wide variation, particularly at the L5–S1 in the Asian adult population, and the facet joint orientation had a relationship with the CSA of the erector spinae at the L4–5.

  2. Giant solitary thoracic osteochondroma arising from the facet joint: A case report and review of the literature

    Energy Technology Data Exchange (ETDEWEB)

    Turgut, Mehmet [Department of Neurosurgery, Adnan Menderes University School of Medicine, TR-09100 Aydin (Turkey)], E-mail: drmturgut@yahoo.com; Meteoglu, Ibrahim; Erdogdu, Ibrahim Halil [Department of Pathology, Adnan Menderes University School of Medicine, TR-09100 Aydin (Turkey)

    2008-08-15

    The authors report a relatively rare case of a giant thoracic solitary osteochondroma arising from the facet joint of T9 vertebra and involving the corresponding transverse process and rib. A 39-year-old woman presented with pain in the back. Neuroradiological evaluation of the spine showed a giant mass lesion involving the facet joint of T9 vertebra and concomitant corresponding transverse process and rib on the left side. At surgery, a firm and cartilaginous tumour originating from the facet joint was radically excised and surgical curettage of the lesion was performed. Histological examination revealed that the lesion was osteochondroma. It is concluded that accurate and prompt diagnosis requires high index of suspicion followed by surgical treatment to prevent severe morbidity in cases of primary spinal column tumours.

  3. Delayed surgical treatment for a traumatic bilateral cervical facet joint dislocation using a posterior-anterior approach: a case report

    Directory of Open Access Journals (Sweden)

    Shimada Takashi

    2013-01-01

    Full Text Available Abstract Introduction There have been few reports of patients with bilateral cervical facet dislocations that remain untreated for eight weeks or more. We report the case of a 76-year-old man with an old bilateral cervical facet joint dislocation fracture that was treated by posterior-anterior reduction and fixation. Case presentation A 76-year-old Asian man was involved in a road traffic accident. He presented with neck pain and arm pain on his right side, but motor weakness and paralysis were not observed. He was treated conservatively; however, instability and spondylolisthesis at the C5 to C6 joint increased eight weeks after the injury. We performed a posterior-anterior reduction and fixation. After surgery, bony union was achieved, and his neck pain and arm pain disappeared. Conclusion We recommend reduction and fixation surgery if a patient has an old bilateral facet joint dislocation fracture in the cervical spine.

  4. Lumbar facet joint synovial cysts: does T2 signal intensity predict outcomes after percutaneous rupture?

    Science.gov (United States)

    Cambron, S C; McIntyre, J J; Guerin, S J; Li, Z; Pastel, D A

    2013-08-01

    Lumbar facet synovial cysts are a cause of back pain and radiculopathy with facet joint degeneration, the most common cause for cyst formation. Typically, LFSCs are T2 hyperintense on MR imaging, but the signal intensity is variable. Treatment options include percutaneous rupture and surgical resection. This study evaluates the relationship between LFSC signal intensity on MR imaging and outcomes as it relates to percutaneous rupture success and need for subsequent surgery. A retrospective review of 110 patients who underwent CT fluoroscopic-guided rupture of symptomatic LFSCs was performed. The LFSCs were characterized by their T2 signal intensity on MR imaging and divided into 3 groups: high, intermediate, and low T2 signal intensity. The rates of successful cyst rupture and need for subsequent surgery were recorded. Percutaneous LFSC rupture was technically successful in 87% of all cases. Cyst rupture was successful in 89% and 90% of high and intermediate signal intensity cysts, respectively, and in 65% of low signal intensity cysts (P = .017, .030). High signal intensity cysts had lower postprocedural surgical rates (29%) when compared with intermediate and low signal cyst as a group (P = .045). T2 hyperintense and intermediate signal intensity LFSCs are easier to rupture, perhaps because the cysts contain a higher proportion of fluid and are less gelatinous or calcified than T2 hypointense cysts. Patients with T2 hyperintense LFSCs are less likely to need surgery.

  5. Internal morphology of human facet joints: comparing cervical and lumbar spine with regard to age, gender and the vertebral core.

    Science.gov (United States)

    Wilke, Hans-Joachim; Zanker, Daniel; Wolfram, Uwe

    2012-03-01

    Back pain constitutes a major problem in modern societies. Facet joints are increasingly recognised as a source of such pain. Knowledge about the internal morphology and its changes with age may make it possible to include the facets more in therapeutic strategies, for instance joint replacements or immobilisation. In total, 168 facets from C6/7 and L4/5 segments were scanned in a micro-computed tomography. Image analysis was used to investigate the internal morphology with regard to donor age and gender. Additional data from trabecular bone of the vertebral core allowed a semi-quantitative comparison of the morphology of the vertebral core and the facets. Porosity and pore spacing of the cortical sub-chondral bone does not appear to change with age for either males or females. In contrast, bone volume fraction decreases in females from approximately 0.4 to 0.2 , whereas it is constant in males. Trabecular thickness decreases during the ageing process in females and stays constant in males , whereas trabecular separation increases during the ageing process in both genders. The results of this study may help to improve the understanding of pathophysiological changes in the facet joints. Such results could be of value for understanding back pain and its treatment.

  6. Joint Force Quarterly. Issue 37

    Science.gov (United States)

    2005-04-01

    Cooperation: The First Step by Matthew F. Bogdanos 19 U.S. European Command and Transformation by Charles F. Wald 27 Transformation and the...JFCOM) found that “JIACG has gained universal acceptance.”1 Deputy Secretary of Defense Paul Wolfowitz then notified Deputy National Secu- rity... Wolfowitz , “Joint Interagency Coordination Groups (JIACG) Assessment,” memoran- dum for the Assistant to the President and Deputy National Security

  7. A novel approach to symptomatic lumbar facet joint synovial cyst injection and rupture using iGuide navigational software: A case report and review.

    Science.gov (United States)

    Wang, David J; Lownie, Stephen P; Pelz, David; Pandey, Sachin

    2016-10-01

    Spinal synovial cysts are benign protrusions of facet joint capsules caused by degenerative spondylosis, most frequently involving the L4-5 level, and commonly lead to symptoms of back pain, radiculopathy and neurogenic claudication. Although percutaneous treatment via facet joint steroid injection with cyst rupture can provide significant symptom relief, cyst rupture is not always achievable via an indirect trans-facet approach due to limited access from severe degenerative changes. In this case, we describe a successful approach to direct cyst access using a laser-guided navigational software in a patient with severe facet joint osteophytosis. We provide a brief review of literature. © The Author(s) 2016.

  8. Is sustained natural apophyseal glides combined with conventional physiotherapy effective for patients with facet joint syndrome? – A case series

    Directory of Open Access Journals (Sweden)

    Deepak B. Anap, Subhash Khatri, Zambre BR

    2014-11-01

    Full Text Available Background: Chronic back pain has been the nemesis of the human race since the time they evolved and began walking on their two legs; leaving aside the 4 limb locomotion of their predecessors. Varied are the causes of low back ache and facet joint syndrome is one amongst them. Hence this study was undertaken to find out the effectiveness of SNAGS and conventional physiotherapy in patients with lumbar facet joint syndrome. Purpose: To describe the management and outcomes of 4 patients with lumbar facet joint syndrome treated with Sustained Natural apophyseal glides (SNAGs, Therapeutic Ultrasound and lumbar stabilization exercises. Study Design : A case series of consecutive patients with Lumbar facet syndrome Case Description: Four consecutive patients (mean age 52 years who presented with lumbar facet syndrome were treated with two weeks protocol which included Sustained Natural apophyseal glides, Therapeutic Ultrasound (Cont. 1-MHz , 2.0-W/cm2, 10min and lumbar stabilization exercises. Follow up was taken 1 week after the end of active intervention. All patients completed Visual analogue Scale (VAS, Modified Oswestery Disability Questionnaire (MODQ, Sorensen Test hold Timing and spinal Range of motion on initial assessment, immediately at the end of active intervention (2 weeks and at the end of follow up. Outcome: All four patients showed the mean percentage change in score of VAS 49.87 %, MODQ 61.14 %, Sorensen test scores 19.63 %, Flexion range 9.21 % and extend range 17.07 % at the end of follow up. Conclusion: All four patients with Lumbar facet joint syndrome treated with sustained natural apophyseal glides (SNAGS, Therapeutic Ultrasound and lumbar stabilisation exercises exhibited reduced pain, reduced disability, improved endurance of back muscles and range of motion at the time follow-up.

  9. Management of low back pain with facet joint injections and nerve root blocks under computed tomography guidance. A prospective study

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    Fotiadou, Anastasia; Wojcik, Andrew; Shaju, Antony [Hinchingbrooke Hospital NHS Trust, Huntingdon, Cambridge (United Kingdom)

    2012-09-15

    The aim of this work was to assess the performance of facet joint and nerve root infiltrations under computed tomography guidance for the management of low back pain and to investigate the complications and patient tolerance. The study was board-certified and informed consent was obtained from all patients. In 1 year, 86 consecutive patients (47 male, 39 female, age range 47-87 years, mean age 63) with low back pain for more than 2 years were included. All patients were clinically examined and had cross-sectional imaging performed before the procedure. Fifty-five facet joint infiltrations and 31 nerve blocks were performed under computed tomography guidance. All patients completed two valid pain questionnaires before and 3 months after the procedures. At the same time, they were clinically examined by the referring Orthopaedic Surgeon. The pain response was assessed by comparing the scores of the questionnaires. The improvement in clinical examination findings was assessed as well. In patients who underwent facet joint infiltrations, long-term pain improvement was achieved in 79% and in those with nerve blocks in 85%. Immediate pain relief was demonstrated in 83% of patients with nerve infiltrations. No complications were observed. All procedures were very well tolerated by patients. Facet joint and nerve infiltrations under computed tomography guidance constitute an accurate and safe method that could be used to relieve low back pain and minimize the risk of disability. (orig.)

  10. Defending the Joint Force: Lessons Learned from Joint Base Balad

    Science.gov (United States)

    2011-01-01

    the enemy’s aerial power by destroying his nests and eggs on the ground than to hunt his flying birds in the air.”1 This concept is reflected in Air...in defending its own assets and those of the joint force.  1. Giulio Douhet, The Command of the Air, trans. Dino Ferrari (1942; new imprint

  11. Diagnostic value of lumbar facet joint injection: a prospective triple cross-over study.

    Directory of Open Access Journals (Sweden)

    Uwe Schütz

    Full Text Available The diagnosis "lumbar facet syndrome" is common and often indicates severe lumbar spine surgery procedures. It is doubtful whether a painful facet joint (FJ can be identified by a single FJ block. The aim of this study was to clarify the validity of a single and placebo controlled bilateral FJ blocks using local anesthetics. A prospective single blinded triple cross-over study was performed. 60 patients (31 f, 29 m, mean age 53.2 yrs (22-73 with chronic low back pain (mean pain persistance 31 months, 6 months of conservative treatment without success admitted to a local orthopaedic department for surgical or conservative therapy of chronic LBP, were included in the study. Effect on pain reduction (10 point rating scale was measured. The 60 subjects were divided into six groups with three defined sequences of fluoroscopically guided bilateral monosegmental lumbar FJ test injections in "oblique needle" technique: verum-(local anaesthetic-, placebo-(sodium chloride- and sham-injection. Carry-over and periodic effects were evaluated and a descriptive and statistical analysis regarding the effectiveness, difference and equality of the FJ injections and the different responses was performed. The results show a high rate of non-response, which documents the lack of reliable and valid predictors for a positive response towards FJ blocks. There was a high rate of placebo reactions noted, including subjects who previously or later reacted positively to verum injections. Equivalence was shown among verum vs. placebo and partly vs. sham also. With regard to test validity criteria, a single intraarticular FJ block with local anesthetics is not useful to detect the pain-responsible FJ and therefore is no valid and reliable diagostic tool to specify indication of lumbar spine surgery. Comparative FJ blocks with local anesthetics and placebo-controls have to be interpretated carefully also, because they solely give no proper diagnosis on FJ being main pain

  12. Whiplash-like facet joint loading initiates glutamatergic responses in the DRG and spinal cord associated with behavioral hypersensitivity

    Science.gov (United States)

    Dong, Ling; Quindlen, Julia C.; Lipschutz, Daniel E.; Winkelstein, Beth A.

    2012-01-01

    The cervical facet joint and its capsule are a common source of neck pain from whiplash. Mechanical hyperalgesia elicited by painful facet joint distraction is associated with spinal neuronal hyperexcitability that can be induced by transmitter/receptor systems that potentiate the synaptic activation of neurons. This study investigated the temporal response of a glutamate receptor and transporters in the dorsal root ganglia (DRG) and spinal cord. Bilateral C6/C7 facet joint distractions were imposed in the rat either to produce behavioral sensitivity or without inducing any sensitivity. Neuronal metabotropic glutamate receptor-5 (mGluR5) and protein kinase C-epsilon (PKCε) expression in the DRG and spinal cord were evaluated on days 1 and 7. Spinal expression of a glutamate transporter, excitatory amino acid carrier 1 (EAAC1), was also quantified at both time points. Painful distraction produced immediate behavioral hypersensitivity that was sustained for 7 days. Increased expression of mGluR5 and PKCε in the DRG was not evident until day 7 and only following painful distraction; this increase was observed in small-diameter neurons. Only painful facet joint distraction produced a significant increase (p<0.001) in neuronal mGluR5 over time, and this increase also was significantly elevated (p ≤ 0.05) over responses in the other groups at day 7. However, there were no differences in spinal PKCε expression on either day or between groups. Spinal EAAC1 expression was significantly increased (p<0.03) only in the nonpainful groups on day 7. Results from this study suggest spinal glutamatergic plasticity is selectively modulated in association with facet-mediated pain. PMID:22578356

  13. The effect of augmented reality training on percutaneous needle placement in spinal facet joint injections.

    Science.gov (United States)

    Yeo, Caitlin T; Ungi, Tamas; U-Thainual, Paweena; Lasso, Andras; McGraw, Robert C; Fichtinger, Gabor

    2011-07-01

    The purpose of this study was to determine if augmented reality image overlay and laser guidance systems can assist medical trainees in learning the correct placement of a needle for percutaneous facet joint injection. The Perk Station training suite was used to conduct and record the needle insertion procedures. A total of 40 volunteers were randomized into two groups of 20. 1) The Overlay group received a training session that consisted of four insertions with image and laser guidance, followed by two insertions with laser overlay only. 2) The Control group received a training session of six classical freehand insertions. Both groups then conducted two freehand insertions. The movement of the needle was tracked during the series of insertions. The final insertion procedure was assessed to determine if there was a benefit to the overlay method compared to the freehand insertions. The Overlay group had a better success rate (83.3% versus 68.4%, p=0.002), and potential for less tissue damage as measured by the amount of needle movement inside the phantom (3077.6 mm(2) versus 5607.9 mm(2) , p =0.01). These results suggest that an augmented reality overlay guidance system can assist medical trainees in acquiring technical competence in a percutaneous needle insertion procedure. © 2011 IEEE

  14. A CT-Based Simulation Study to Compare the Risk of Facet Joint Violation by the Cervical Pedicle Screw Between Degenerative and Nondegenerative Cervical Spines.

    Science.gov (United States)

    Lee, Dong-Ho; Noh, Hyounmin; Hwang, Chang Ju; Lee, Choon Sung; Abumi, Kuniyoshi; Cho, Jae Hwan

    2017-02-01

    A retrospective case-control study. This study aimed (A) to compare entry points and trajectories of the cervical pedicle screw (CPS) between degenerative and nondegenerative spines, and (B) to evaluate the risk of facet joint violation by the CPS according to the degree of facet degeneration. Entry point, trajectories, and risk of misplacement of the CPS have been widely researched; however, its application to degenerative cervical spine has to be elucidated. Sixty patients who underwent cervical surgeries at our institution were classified into two groups according to cervical facet joint degeneration. A simulation program with 0.7-mm thickness axial computed tomographic images was used to evaluate facet joint violation by the CPS from C3 to C6. Horizontal and vertical offsets of entry points were measured from two different anatomical landmarks on lateral mass, namely the lateral notch and the center of the superior ridge. The transverse and sagittal angles of the screws were also measured. Facet joint violation was evaluated and classified into either "minor" (cervical spine group at all levels (P = 0.001-0.026). In addition, facet joint violation was more frequently found in severely degenerated facet joints than in mild to moderately degenerated facet joints (P = 0.011). The entry point of CPS was moved more superiorly in the degenerative cervical spine in this study, which increased the risk of facet joint violation in our patients. Thus, surgeons need to modify the insertion technique of the CPS or to insert lateral mass screw instead of the CPS when it is considered to insert screws at the uppermost vertebra in the degenerative cervical spine. 4.

  15. Systematic review of patient history and physical examination to diagnose chronic low back pain originating from the facet joints.

    Science.gov (United States)

    Maas, E T; Juch, J N S; Ostelo, R W J G; Groeneweg, J G; Kallewaard, J W; Koes, B W; Verhagen, A P; Huygen, F J P M; van Tulder, M W

    2017-03-01

    Patient history and physical examination are frequently used procedures to diagnose chronic low back pain (CLBP) originating from the facet joints, although the diagnostic accuracy is controversial. The aim of this systematic review is to determine the diagnostic accuracy of patient history and/or physical examination to identify CLBP originating from the facet joints using diagnostic blocks as reference standard. We searched MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Collaboration database from inception until June 2016. Two review authors independently selected studies for inclusion, extracted data and assessed the risk of bias. We calculated sensitivity and specificity values, with 95% confidence intervals (95% CI). Twelve studies were included, in which 129 combinations of index tests and reference standards were presented. Most of these index tests have only been evaluated in single studies with a high risk of bias. Four studies evaluated the diagnostic accuracy of the Revel's criteria combination. Because of the clinical heterogeneity, results were not pooled. The published sensitivities ranged from 0.11 (95% CI 0.02-0.29) to 1.00 (95% CI 0.75-1.00), and the specificities ranged from 0.66 (95% CI 0.46-0.82) to 0.91 (95% CI 0.83-0.96). Due to clinical heterogeneity, the evidence for the diagnostic accuracy of patient history and/or physical examination to identify facet joint pain is inconclusive. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies.

  16. Joint Force Quarterly. Number 8, Summer 1995

    Science.gov (United States)

    1995-06-01

    College of the Armed Forces COL Peter F. Herrly, USA National War College Col Douglas N. Hime, USAF Naval War College William T. Hodson Information...airmen who fought as a team to lay the foundations of joint and combined warfare. JFQ N O T E S 1 See, for example, statements by Ernest J. King and...on invading North Africa in 1942, a move vehemently opposed by his main mili- tary advisors, General George C. Marshall and Admiral Ernest J. King

  17. Joint Force Quarterly. Number 1, Summer 1993

    Science.gov (United States)

    1993-01-01

    conduct joint operations to only “higher” levels is a recipe for missed opportunities, longer and more difficult operations, riskier outcomes, greater...changed the face of Europe, Asia, and Africa. The passing of the Cold War now has map-makers scrambling for pens and fresh ink, while territorial squabbles...America’s future is best served by a force mix that does not place too many eggs in any one basket, but which in- stead draws on the synergy of

  18. Joint force opportunities: Policy Aims And Adaptations

    Science.gov (United States)

    2016-05-26

    father for feeding a passion for learning with a work ethic ; and your patient love. To D, B, and C: I love you eternally. v...institutions can assist that adaptation. Future adaptation by the joint force depends on better conceptualizing complexity while still aligning ethically ...Organization Theory: Modern, Symbolic And Postmodern Perspectives. New York: Oxford University Press, 1997. Hendawi, Hamza Hendawi. "ISIS Top Brass Is Iraqi

  19. Symptomatic lumbar facet joint cysts treated by CT-guided intracystic and intra-articular steroid injections

    Energy Technology Data Exchange (ETDEWEB)

    Amoretti, Nicolas; Huwart, Laurent; Amoretti, Marie-Eve; Pellegrin, Amelie; Marcy, Pierre-Yves [Centre Hospital-Universitaire de Nice, Hopital Archet 2, Department of Radiology, Nice (France); Foti, Pauline [Centre Hospital-Universitaire de Nice, Departments of Epidemiology, Nice (France); Boileau, Pascal [Centre Hospital-Universitaire de Nice, Orthopaedic Surgery, Nice (France); Hauger, Olivier [Hopital Pellegrin, Centre Hospitalo-Universitaire de Bordeaux, Department of Radiology, Bordeaux (France)

    2012-12-15

    To evaluate percutaneous computed tomography (CT)-guided intracystic and intra-articular steroid injections for the treatment of lumbar facet joint cyst causing radicular pain. A single-centre prospective study involving 120 consecutive patients with symptomatic lumbar facet joint cyst-induced radicular pain was done (72 women, 48 men). The average age was 68.2 years (52-84). Patients were treated by percutaneous CT-guided intracystic and intra-articular steroid injections. The clinical course of nerve root pain was evaluated after 1 day, and 1, 3 and 6 months, with long-term follow-up after 12 months. Patient follow-ups in our series show supportive results: within 120 patients, 54% of patients were satisfied with a long-lasting result from the first intra-cystic and intra-articular steroid injections (n = 65), while 20.8% were satisfied with a long-lasting result from a second intervention. Combining these two results shows that 75% of patients were satisfied with a long-lasting result. Our results showed that percutaneous treatment of vertebral lumbar facet joint cysts by double injections is an effective and economic therapeutic technical management among 75% of our patients. Thus we recommend that it should be considered as a first choice of treatment. (orig.)

  20. Treatment of lumbar facet joint syndrome by CT-guided intraarticular infiltration of fact joints; Behandlung des lumbalen Facettensyndroms durch CT-gesteuerte Infiltration der Zwischenwirbelgelenke

    Energy Technology Data Exchange (ETDEWEB)

    Schleifer, J. [Knappschaftsklinik Puettlingen/Saar (Germany). Orthopaedische Abteilung; Fenzl, G. [Knappschaftsklinik Puettlingen/Saar (Germany). Orthopaedische Abteilung; Wolf, A. [Knappschaftsklinik Puettlingen/Saar (Germany). Radiologische Abteilung; Diehl, K. [Knappschaftsklinik Puettlingen/Saar (Germany). Radiologische Abteilung

    1994-11-01

    In 62 patients with facet syndrome a total of 205 joints were infiltrated, CT monitoring being used in all cases. Each facet joint was infiltrated with 0.3 ml bupivacaine and 0.8 ml methylprednisolone. The patients were divided into three groups. Group 1 consisted of 24 persons who had undergone lumbar disc surgery, group 2 of 23 patients with spondylarthrosis of the facet joints, and group 3 of 15 patients who had undergone lumbar disc surgery but hat additional spondylarthrosis. Very good results were defined as pain relief for longer than 4 weeks, good results as pain relief for up to 4 weeks and poor results as brief pain relief or none at all. In 27 patients facet infiltration was performed for the purpose of diagnosis. Results were significantly in group 2 than in group 1. In group 3 results were better than in group 1, but worse than in group 2. These differences were not statistical by significant. Seven patients in the diagnostic group had no pain relief, and facet syndrome was excluded. (orig.) [Deutsch] Bei 62 Patienten mit lumbalem Facettensyndrom wurden insgesamt 205 Zwischenwirbelgelenke (Facettengelenke) perkutan CT-gesteuert infiltriert. Je Gelenk wurden 0,3 ml Bupivacain und 0,8 ml Methylprednisolon intraartikulaer infiziert. Die Patienten wurden in 3 Gruppen unterteilt. Die 1. Gruppe umfasste 24 Patienten mit Postnukleotomiesyndrom, die 2. Gruppe 23 Patienten mit spondylarthrotischen Veraenderungen, die 3. Gruppe 15 bandscheibenoperierte Patienten mit zusaetzlicher Spondylarthrose. In Gruppe 2 fanden sich signifikant bessere Ergebnisse als in Gruppe 1. Gute Resultate ergab auch die dritte Gruppe, sie waren jedoch nicht signifikant besser als die der Gruppe 1. Die sorgfaeltige Auswahl der Patienten ist fuer den Erfolg der Behandlung entscheidend. Die Infiltrationsbehandlung der Zwischenwirbelgelenke hat nahezu keine Nebenwirkungen. Ausser zur Therapie wird das Verfahren diagnostisch zum Ausschluss eines Facettensyndromes im Rahmen der Abklaerung

  1. Significance of interfacet distance, facet joint orientation, and lumbar lordosis in spondylolysis.

    Science.gov (United States)

    Chung, Sang-Bong; Lee, Sungjoon; Kim, Hoon; Lee, Sun-Ho; Kim, Eun Sang; Eoh, Whan

    2012-04-01

    The aim of this study is to reveal the association between lumbar spondylolysis and several radiologic parameters, which had been suggested to be significant. The authors examine interfacet distance (IFD), facet joint orientation (FJO), and lumbar segmental lordosis (LSL) all together on the basis of lumbar computed tomography (CT) scan of 35 patients with L5 spondylolysis and 36 unaffected control groups. Thirty-five Korean military recruits, aged 19-23 (mean 20.9 years), were diagnosed as L5 spondylolysis by lumber CT scans. As a control group, 36 male Korean military recruits, aged 18-25 (mean 21.3 years), were reconfirmed as not affected by lumbar spondylolysis by CT scan when they visited our hospital complaining of back pain. This study compares IFD, FJO, and LSL for each lumbar segment between the spondylolytic and unaffected groups. We also propose the use of normal mean data of IFD, FJO, and LSL of lumbar vertebrae from 36 Korean young military recruits because each measurement has power as an absolute value, like data from an osteologic collection in other studies. Comparison of IFD between spondylolytic and unaffected individuals reveals significant differences at the L3, L4, and L5 level (P = 0.0384, P = 0.0219, and P lordosis were significantly different between patients with L5 spondylolysis and individuals without pars defect on L5. In the spondylolysis group, and the increase of IFD from L4 to S1 was less pronounced and the LSL at L5-S1 was more lordotic. Copyright © 2011 Wiley Periodicals, Inc.

  2. How to Reduce Bilateral Cervical Facet Joint Dislocation in Anterior Approach: A Trick to Avoid Anterior-Posterior-Anterior Surgical Procedures

    National Research Council Canada - National Science Library

    Jaeger, Martin

    2015-01-01

    .... These flexion distraction lesions in cervical spine occur as a subluxation or unilateral/bilateral dislocation of the facet joints, which often be accompanied by direct spinal cord and nerve root injury...

  3. Fluoroscopy-guided intrA-articular facet joint steroid injection for the management of low back pain: Therapeutic effectiveness and arthrographic pattern

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Su Jin; Lee, Jun Woo; Lee, Guen Young; You, Ja Yeon; Kang, Heung Sik [Dept. of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam (Korea, Republic of); Chai, Jae Won [Dept. of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Ahn, Joong Mo [Dept. of Radiology, University of Pittsburgh Medical Center, Pittsburgh (United States)

    2015-09-15

    To evaluate the effectiveness of fluoroscopy-guided intra-articular facet joint steroid injection for the management of low back pain, and to document the incidence of epidural leakage. In total, 320 facet joint injections of 244 consecutive patients were included in this study. All patients had undergone an intra-articular facet joint steroid injection in 2007 and had follow-up post-treatment medical records. The response to treatment was analyzed on the basis of chart documentation (aggravated, no change, slightly improved, much improved, no pain). Fluoroscopic arthrograms of the injections were retrospectively analyzed by two radiologists. Of the 244 patients, 85.2% (n = 208) showed improvement after an initial intra-articular facet joint steroid injection. A total of 77.9% (n = 162) of the patients showed symptom recurrence, with a median of a 69 day symptom-free interval, while 30.3% (n = 74) of the patients showed symptom-free intervals of more than six months. Overall, 74 (33.3%) of the 222 cases of intra-articular facet joint steroid injections without concomitant epidural steroid injection showed epidural leakage in fluoroscopic arthrograms. Fluoroscopy-guided intra-articular facet joint injection is a reliable technique for the management of low back pain, with excellent immediate effectiveness and good prolonged (> 2 months) pain relief. Epidural leakage during injection was detected in one-third of the cases.

  4. JOINT FORCE AND CONTEMPORARY MILITARY ACTIONS

    Directory of Open Access Journals (Sweden)

    Codrin HERTANU

    2012-01-01

    Full Text Available In the current changing international context, the worldwide power balance along with its inter-dependencies shows that mankind is facing problems and pressures posed by resources limitation (the oil ones being the most relevant dramatic climate evolution and a decisive impact of technologies. The approach of the armed forces to the national defense related interests, as well as to the asymmetrical and irregular threats underlines the joint force’s capacity to be the most powerful and adequate tool to address all of these.

  5. Imaging by atomic force microscopy of the properties difference of the layers covering the facets created during SIMS analysis

    Science.gov (United States)

    Fares, B.; Gautier, B.; Albertini, D.; Mzerd, A.; Loghmarti, M.

    2014-07-01

    Atomic force microscopy (AFM) is used in tapping mode in order to study the roughness created in the crater bottom during secondary ions mass spectrometry (SIMS) analysis in silicon, using O2+ primary ions without flooding. Previous studies of the chemical composition of the facets created during the analysis have lead to the conclusion that the facets oriented toward the O2+ beam during the ionic bombardment were close to SiO2 in composition, while the facets hidden from the beam were covered with a sub-stoichiometric oxide SiOx (with x composition difference, revealing a sharp contrast between the facets. The observed contrast may arise from the different chemical composition of the facets, leading to a different energy dissipation of the tip/sample system over Si and SiO2 due to the different properties of the materials (hardness, adhesion, etc.). As a comparison, an observation of a surface covered with SiO2 and Si (SiO2 deposed with a 90 nm or 4 nm thickness, and partially removed from a Si surface) shows the same kind of contrast.

  6. Biomechanical analysis of press-extension technique on degenerative lumbar with disc herniation and staggered facet joint.

    Science.gov (United States)

    Du, Hong-Gen; Liao, Sheng-Hui; Jiang, Zhong; Huang, Huan-Ming; Ning, Xi-Tao; Jiang, Neng-Yi; Pei, Jian-Wei; Huang, Qin; Wei, Hui

    2016-05-01

    This study investigates the effect of a new Chinese massage technique named "press-extension" on degenerative lumbar with disc herniation and facet joint dislocation, and provides a biomechanical explanation of this massage technique. Self-developed biomechanical software was used to establish a normal L1-S1 lumbar 3D FE model, which integrated the spine CT and MRI data-based anatomical structure. Then graphic technique is utilized to build a degenerative lumbar FE model with disc herniation and facet joint dislocation. According to the actual press-extension experiments, mechanic parameters are collected to set boundary condition for FE analysis. The result demonstrated that press-extension techniques bring the annuli fibrosi obvious induction effect, making the central nucleus pulposus forward close, increasing the pressure in front part. Study concludes that finite element modelling for lumbar spine is suitable for the analysis of press-extension technique impact on lumbar intervertebral disc biomechanics, to provide the basis for the disease mechanism of intervertebral disc herniation using press-extension technique.

  7. Termocoagulación facetaria lumbar: Experiencia en 252 pacientes Thermocoagulation of lumbar facet joints: Experience in 252 patients

    Directory of Open Access Journals (Sweden)

    J. E. Martínez-Suárez

    2005-10-01

    Full Text Available Se presentan 252 pacientes con el diagnóstico de dolor lumbar facetario a los que se le realizó la técnica quirúrgica de termocoagulación percutánea de la faceta articular. Nuestro propósito principal fue aliviar el dolor en estos pacientes, evaluamos la eficacia de la técnica con un 74,7% de resultados quirúrgicos satisfactorios, así como la descripción de diferentes aspectos como: edad, sexo, causas y la topografía segmentaria del dolor.Two hundred fifty two patients with diagnosis of lumbar facet joint pain underwent the surgical technique of percutaneous thermocoagulation of the facet joint. Our major aim was to relief pain in those patients. We assess the effectiveness of the technique, with 74.7% of surgical success, and we also describe different aspects such as: age, sex, causes and segmentary pain topography.

  8. Quantitative Methods for Analysing Joint Questionnaire Data: Exploring the Role of Joint in Force Design

    Science.gov (United States)

    2015-08-01

    UNCLASSIFIED UNCLASSIFIED Quantitative Methods for Analysing Joint Questionnaire Data: Exploring the Role of Joint in Force Design David...joint activities selected by respondents, and the small sample size, quantitative analysis was conducted on the collected data. This statistical...APPROVED FOR PUBLIC RELEASE UNCLASSIFIED UNCLASSIFIED Quantitative Methods for Analysing Joint Questionnaire Data: Exploring the Role of

  9. Fluoroscopic caudal epidural injections in managing chronic axial low back pain without disc herniation, radiculitis, or facet joint pain

    Directory of Open Access Journals (Sweden)

    Manchikanti L

    2012-10-01

    Full Text Available Laxmaiah Manchikanti,1,2 Kimberly A Cash,1 Carla D McManus,1 Vidyasagar Pampati11Pain Management Center of Paducah, Paducah, 2Department of Anesthesiology and Perioperative Medicine, University of Louisville, Louisville, KY, USABackground: Chronic low back pain without disc herniation is common. Various modalities of treatments are utilized in managing this condition, including epidural injections. However, there is continued debate on the effectiveness, indications, and medical necessity of any treatment modality utilized for managing axial or discogenic pain, including epidural injections.Methods: A randomized, double-blind, actively controlled trial was conducted. The objective was to evaluate the ability to assess the effectiveness of caudal epidural injections of local anesthetic with or without steroids for managing chronic low back pain not caused by disc herniation, radiculitis, facet joints, or sacroiliac joints. A total of 120 patients were randomized to two groups; one group did not receive steroids (group 1 and the other group did (group 2. There were 60 patients in each group. The primary outcome measure was at least 50% improvement in Numeric Rating Scale and Oswestry Disability Index. Secondary outcome measures were employment status and opioid intake. These measures were assessed at 3, 6, 12, 18, and 24 months after treatment.Results: Significant pain relief and functional status improvement (primary outcome defined as a 50% or more reduction in scores from baseline, were observed in 54% of patients in group 1 and 60% of patients in group 2 at 24 months. In contrast, 84% of patients in group 1 and 73% in group 2 saw significant pain relief and functional status improvement in the successful groups at 24 months.Conclusion: Caudal epidural injections of local anesthetic with or without steroids are effective in patients with chronic axial low back pain of discogenic origin without facet joint pain, disc herniation, and

  10. Battlefield Renewable Energy: A Key Joint Force Enabler

    Science.gov (United States)

    2010-06-01

    Environment, Energy Security & Sustainability Symposium Jun 2010 Battlefield Renewable Energy A Key Joint Force Enabler Roy H. Adams III, LTC, USA...COVERED 00-00-2010 to 00-00-2010 4. TITLE AND SUBTITLE Battlefield Renewable Energy : A Key Joint Force Enabler 5a. CONTRACT NUMBER 5b. GRANT

  11. Lumbar facet syndromes.

    Science.gov (United States)

    Beresford, Zach M; Kendall, Richard W; Willick, Stuart E

    2010-01-01

    Low back pain is a common presenting complaint to sports medicine providers. The lumbar spine is a complex anatomic structure with multiple potential pain generators. Epidemiologic studies have shown that the intervertebral disc is the most common pain generator in all patients with low back pain. The facet joints may account for 15%-40% of low back pain. It can be challenging at times to establish a firm diagnosis of facet pain. Facet pain can have different presentations, and pain emanating from other lumbopelvic structures can present similarly as facet joint pain. This article reviews the anatomy and biomechanics of the lumbar facet joints, presenting symptoms and physical examination findings seen with facet pain. We also will discuss diagnostic and treatment paradigms that are helpful to the clinician treating low back pain in athletes.

  12. Bloqueos diagnóstico-terapéuticos de carillas articulares cervicales Diagnostic-therapeutic cervical facet joint blocks

    Directory of Open Access Journals (Sweden)

    M.L. Franco

    2009-03-01

    Full Text Available El 66% de los adultos experimenta dolor cervical a lo largo de su vida y el 54% lo ha experimentado durante los pasados 6 meses. Sólo el 5% presentará dolor crónico intenso acompañado de incapacidad funcional. El 80% del dolor cervical se produce por lesiones óseas o musculares como consecuencia de la degeneración discal y facetaria, a lo que se pueden sumar agentes externos, como traumatismo, sobrepeso, sobrecargas laborales, estrés, etc. El diagnóstico del dolor cervical se basa, fundamentalmente, en la exploración física y en la clínica del paciente. Ante la presencia de dolor cervical irradiado a nuca, cintura escapulohumeral y miembro superior derecho sin patrón radicular con exploración positiva en carillas articulares, están indicados los bloqueos diagnóstico-terapéuticos de éstas. En el trabajo se describe la anatomía de la región cervical, cuyo conocimiento es imprescindible tanto para garantizar los buenos resultados, como para minimizar los riesgos, así como las indicaciones y práctica de la técnica.Cervical pain is experienced by 66% of adults during their lifetime and by 54% in the previous 6 months. Only 5% will experience intense chronic pain with functional disability. Eighty percent of cervical pain is produced by skeletal or muscular lesions as a result of disc and facet degeneration. External causative agents include trauma, overweight, occupational demands, stress, etc. Diagnosis of cervical pain is mainly based on physical examination and clinical findings. In cervical pain radiating to the neck, scapulohumeral girdle and upper right arm without a radicular pattern and positive examination of the facet joints, diagnostic-therapeutic facet joint blocks are indicated. The present article describes the anatomy of the cervical region. Knowledge of this region is essential to guarantee good results and to minimize risks. The indications and practical features of the technique are also discussed.

  13. A critical evaluation of subtalar joint arthrosis associated with middle facet talocalcaneal coalition in 21 surgically managed patients: a retrospective computed tomography review. Investigations involving middle facet coalitions-part III.

    Science.gov (United States)

    Kernbach, Klaus J; Barkan, Howard; Blitz, Neal M

    2010-01-01

    Symptomatic middle facet talocalcaneal coalition is frequently associated with rearfoot arthrosis that is often managed surgically with rearfoot fusion. However, no objective method for classifying the extent of subtalar joint arthrosis exists. No study has clearly identified the extent of posterior facet arthrosis present in a large cohort treated surgically for talocalcaneal coalition through preoperative computerized axial tomography. The authors conducted a retrospective review of 21 patients (35 feet) with coalition who were surgically treated over a 12-year period for coalition on at least 1 foot. Using a predefined original staging system, the extent of the arthrosis was categorized into normal or mild (Stage I), moderate (Stage II), and severe (Stage III) arthrosis. The association of stage and age is statistically significant. All of the feet with Stage III arthrosis had fibrous coalitions. No foot with osseous coalition had Stage III arthrosis. The distribution of arthrosis staging differs between fibrous and osseous coalitions. Only fibrous coalitions had the most advanced arthrosis (Stage III), whereas osseous coalitions did not. This suggests that osseous coalitions may have a protective effect in the prevention of severe degeneration of the subtalar joint. Concomitant subtalar joint arthrosis severity progresses with age; surgeons may want to consider earlier surgical intervention to prevent arthrosis progression in patients with symptomatic middle facet talocalcaneal coalition.

  14. Lumbar Facet Joint Compressive Injury Induces Lasting Changes in Local Structure, Nociceptive Scores, and Inflammatory Mediators in a Novel Rat Model

    Directory of Open Access Journals (Sweden)

    James L. Henry

    2012-01-01

    Full Text Available Objective. To develop a novel animal model of persisting lumbar facet joint pain. Methods. Sprague Dawley rats were anaesthetized and the right lumbar (L5/L6 facet joint was exposed and compressed to ~1 mm with modified clamps applied for three minutes; sham-operated and naïve animals were used as control groups. After five days, animals were tested for hind-paw sensitivity using von Frey filaments and axial deep tissue sensitivity by algometer on assigned days up to 28 days. Animals were sacrificed at selected times for histological and biochemical analysis. Results. Histological sections revealed site-specific loss of cartilage in model animals only. Tactile hypersensitivity was observed for the ipsi- and contralateral paws lasting 28 days. The threshold at which deep tissue pressure just elicited vocalization was obtained at three lumbar levels; sensitivity at L1>L3/4>L6. Biochemical analyses revealed increases in proinflammatory cytokines, especially TNF-α, IL-1α, and IL-1β. Conclusions. These data suggest that compression of a facet joint induces a novel model of local cartilage loss accompanied by increased sensitivity to mechanical stimuli and by increases in inflammatory mediators. This new model may be useful for studies on mechanisms and treatment of lumbar facet joint pain and osteoarthritis.

  15. Evaluation of a Robotic Assistance-System For Percutaneous Computed Tomography-Guided (CT-Guided) Facet Joint Injection: A Phantom Study.

    Science.gov (United States)

    Beyer, Lukas Philipp; Michalik, Katharina; Niessen, Christoph; Platz Batista da Silva, Natascha; Wiesinger, Isabell; Stroszczynski, Christian; Wiggermann, Philipp

    2016-09-20

    BACKGROUND The aim of this study was to compare robotic assisted and freehand facet joint puncture on a phantom model in regards to time requirements and puncture accuracy. MATERIAL AND METHODS Forty facet joints were punctured, 20 using a robotic guidance system and 20 using a freehand procedure. Side and height of the facet joints were randomized and identical for both groups. Procedural accuracy, defined as axial and sagittal deviation, as well as the number of corrections were assessed. Procedure times for each step were documented and time requirements for pre-positioning, reconstruction, planning, and total intervention were calculated. RESULTS Total procedure time for robotic guidance was 259±111 seconds versus 119±77 seconds for freehand procedure (p=1.0). Procedural accuracy for robotic guidance was significantly higher with 0 corrections versus 1.3 corrections for freehand procedure (p=0.02). Needle deviation in the robotics arm was 0.35±1.1 mm in the axial and 2.15±1.2 mm in the sagittal reconstruction. CONCLUSIONS Robotic assisted puncture of the facet joint allowed accurate positioning of the needle with a lower number of needle readjustments. Higher procedural accuracy was marginally offset by a slightly longer intervention time.

  16. Lumbar disc degeneration was not related to spine and hip bone mineral densities in Chinese: facet joint osteoarthritis may confound the association.

    Science.gov (United States)

    Pan, Jianjiang; Lu, Xuan; Yang, Ge; Han, Yongmei; Tong, Xiang; Wang, Yue

    2017-12-01

    A sample of 512 Chinese was studied and we observed that greater disc degeneration on MRI was associated with greater spine DXA BMD. Yet, this association may be confounded by facet joint osteoarthritis. BMD may not be a risk factor for lumbar disc degeneration in Chinese. Evidence suggested that lumbar vertebral bone and intervertebral disc interact with each other in multiple ways. The current paper aims to determine the association between bone mineral density (BMD) and lumbar disc degeneration using a sample of Chinese. We studied 165 patients with back disorders and 347 general subjects from China. All subjects had lumbar spine magnetic resonance (MR) imaging and dual- energy X-ray absorptiometry (DXA) spine BMD studies, and a subset of general subjects had additional hip BMD measurements. On T2-weighted MR images, Pfirrmann score was used to evaluate the degree of lumbar disc degeneration and facet joint osteoarthritis was assessed as none, slight-moderate, and severe. Regression analyses were used to examine the associations between lumbar and hip BMD and disc degeneration, adjusting for age, gender, body mass index (BMI), lumbar region, and facet joint osteoarthritis. Greater facet joint osteoarthritis was associated with greater spine BMD (P  0.05). No statistical association was observed between spine BMD and lumbar disc degeneration in patients with back disorders (P > 0.05), and between hip BMD and disc degeneration in general subjects (P > 0.05). BMD may not be a risk factor for lumbar disc degeneration in Chinese. Facet joint osteoarthritis inflates DXA spine BMD measurements and therefore, may confound the association between spine BMD and disc degeneration.

  17. An analysis on risk factors for lumbar facet joint osteoarthritis%腰椎小关节骨性关节炎危险因素分析

    Institute of Scientific and Technical Information of China (English)

    王庆华

    2012-01-01

    [Objective]To investigate the risk factors of lumbar facet joint osteoarthritis.[Methods]The ris factors of lumbar facet joint osteoarthritis were analyzed and summarized.[Results]Men aged 50 or older,postmenopausal women,lumbar facet joints tended to the sagittal plane,and lumbar intervertebral disc degeneration of L4 and 5 were the risk factors for lumbar facet joint osteoarthritis.[Conclusion]s The understanding of the risk factors for lumbar facet joint osteoarthritis can help in the diagnosis and treatment of low back pain,with social and economic benefits.%探讨腰椎小关节骨性关节炎危险因素.对以往腰椎小关节骨性关节炎的危险因素进行分析、归纳、研究、总结.研究发现,年龄在50岁以上的男性、绝经之后的女性以及腰椎小关节偏向矢状面和腰椎间盘退变、L4-5节段等为腰椎小关节骨性关节炎的危险因素.通过对腰椎小关节骨性关节炎的危险因素进行研究,能够对下腰痛的诊治提供有效的帮助,具有社会效益与经济效益.

  18. Investigation of stresses in facetted glass shell structures

    DEFF Research Database (Denmark)

    Bagger, Anne; Jönsson, Jeppe; Wester, Ture

    2007-01-01

    The typical use of triangular and quadrangular facets in doubly curved facetted shells requires the use of triangulated truss systems or quadrangular truss framing with diagonals or cross tension cabling. In such a structure, the load carrying ability is based on concentrated forces in the framing...... system, while the glass merely serves as a separation of the inside environment from the outside. In this paper facetted glass shell structures with three way vertices, i.e. with three adjoining edges in each vertex are considered, since the load carrying ability of such a structure is achieved primarily...... by in-plane forces in the facets and the transfer of distributed in-plane forces across the joints. It is described how these facets work structurally, specifically how bending moments develop and cause possible stress concentrations in the corners, which are subjected to uplift. Apart from local...

  19. Joint Force Quarterly. Number 7, Spring 1995

    Science.gov (United States)

    1995-02-01

    height- ened jointness. Large and historic barriers must be negotiated, however, if jointness is to provide synergy on tomorrow’s battle- field. Prior to...become a more diverse panorama of po- litical, military, and economic concerns con- fronting the United States. Consequently, it is more difficult to...fewer synergies with civil- ian society than those in the thrall of postmodern militarism may suppose. Since order and control F R O M T H E F I E

  20. Implementing Joint Operational Access: From Concept to Joint Force Development

    Science.gov (United States)

    2014-01-01

    global commons.2 Potential enemies are developing antiaccess/area-denial (A2/AD) capabilities3 that could threaten access and jeopardize missions...efforts in U.S. 5th Fleet area of responsibility (U.S. Navy/Travis K. Mendoza ) Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...Military Sealift Command fleet replenishment oiler USNS Guadalupe conduct replenishment at sea (U.S. Navy/Travis K. Mendoza ) 142 Joint Doctrine

  1. Cervical Facet Joint Infection and Associated Epidural Abscess with Streptococcus intermedius from a Dental Infection Origin A Case Report and Review.

    Science.gov (United States)

    Kaye, Ian David; Protopsaltis, Themistocles S

    2016-09-01

    Pyogenic cervical facet joint infections are rare and such infections from a dental origin are even less common. Of these few cases, none have described infection with Streptococcus intermedius as the pathogen. A 65-year-old orthopaedic surgeon complained of fevers, right-sided radiating neck pain, stiffness, swelling, erythema, and right upper extremity weakness one month after he had broken a crown over his right mandibular premolar, a continued source of pain. Imaging of the cervical spine showed a right C4-C5 facet inflammatory arthropathy and a small epidural abscess that was cultured and initially treated with intravenous antibiotics. The oral maxillofacial surgery team performed an extraction of the infected, symptomatic tooth. For continued right upper extremity weakness, the patient underwent C4-C5 laminoforaminotomy and irrigation and debridement of the right C4-C5 facet joint. After 6 weeks of intravenous antibiotics, the patient's infectious and inflammatory markers had normalized. By 4 months, he had regained full strength at his upper extremity and a painless and full range of motion of his cervical spine.Pyogenic cervical facet joint infection is very rare and potentially dangerous. A high clinical suspicion and appropriate imaging, including magnetic resonance imaging, are important for correct diagnosis. Prompt medical and surgical treatment may avert complications, and although the patient presented made a complete recovery, patients may be left with neurological compromise.

  2. Differences Regarding Branded HA in Italy, Part 2: Data from Clinical Studies on Knee, Hip, Shoulder, Ankle, Temporomandibular Joint, Vertebral Facets, and Carpometacarpal Joint

    Science.gov (United States)

    Migliore, A.; Bizzi, E.; De Lucia, O.; Delle Sedie, A.; Tropea, S.; Bentivegna, M.; Mahmoud, A.; Foti, C.

    2016-01-01

    OBJECTIVES The aim of the current study is to collect scientific data on all branded hyaluronic acid (HA) products in Italy that are in use for intra-articular (IA) injection in osteoarthritis (OA) compared with that reported in the leaflet. METHODS An extensive literature research was performed for all articles reporting data on the IA use of HA in OA. Selected studies were taken into consideration only if they are related to products based on HAs that are currently marketed in Italy with the specific joint indication for IA use in patients affected by OA. RESULTS Sixty-two HA products are marketed in Italy: 30 products are indicated for the knee but only 8 were proved with some efficacy; 9 products were effective for the hip but only 6 had hip indication; 7 products proved to be effective for the shoulder but only 3 had the indication; 5 products proved effective for the ankle but only one had the indication; 6 products were effective for the temporomandibular joint but only 2 had the indication; only 2 proved effective for vertebral facet joints but only 1 had the indication; and 5 products proved effective for the carpometacarpal joint but only 2 had the indication. CONCLUSIONS There are only a few products with some evidences, while the majority of products remain without proof. Clinicians and regulators should request postmarketing studies from pharmaceuticals to corroborate with that reported in the leaflet and to gather more data, allowing the clinicians to choose the adequate product for the patient. PMID:27279754

  3. Model Testing of Forces in the Reflector Joint and Mooring Forces on Wave Dragon

    DEFF Research Database (Denmark)

    Gilling, Lasse; Kofoed, Jens Peter; Tedd, James

    This report aims to present the results of a test series analysing the forces in the redesigned reflector joint and the forces in the main mooring link. The resluts presented are intended to be used by WD project partners, for the design and construction of the joint on the prototype Wave Dragon...... at Nissum Bredning and for future North Sea scale Wave Dragon. Lengths, forces and other dimentions presented are scaled to the North sea Wave Dragon unless otherwise specified....

  4. Model Testing of Forces in the Reflector Joint and Mooring Forces on Wave Dragon

    DEFF Research Database (Denmark)

    Gilling, Lasse; Kofoed, Jens Peter; Tedd, James

    This report aims to present the results of a test series analysing the forces in the redesigned reflector joint and the forces in the main mooring link. The resluts presented are intended to be used by WD project partners, for the design and construction of the joint on the prototype Wave Dragon...... at Nissum Bredning and for future North Sea scale Wave Dragon. Lengths, forces and other dimentions presented are scaled to the North sea Wave Dragon unless otherwise specified....

  5. Joint Force Quarterly. Number 2, Autumn 1993

    Science.gov (United States)

    1993-09-01

    primary contribution to the military power of the Nation on the ground, at sea, and from the air. — Fleet Admiral Ernest J. King U.S. Navy at War, 1941...William T. Hodson Information Resources Management College COL Richard L. Irby, Jr., USA U.S. Army War College Mark H. Jacobsen Marine Corps Command...inclusion of ar- ticles dealing with jointness from an historical approach. Lord Ernest Rutherford, the British nuclear physicist and Nobel Prize

  6. The Disestablishment of U.S. Joint Forces Command: A Step Backward in "Jointness"

    Science.gov (United States)

    2011-06-01

    during the 1990s, Douglas McGregor commented on Service nent control of Unmanned Aerial Vehicles (UAV) in the Balkans: NATO air strikes against...64 Douglas A. Macgregor, “The Joint Force - A Decade, No Progress,” Joint Force Quarterly Winter 2000-2001, 21...Berteau, Samuel J. Brannen, Eleanore Douglas , Nathan Freier, Clark A. Murdock, Christine E. Wormuth. “Transitioning Defense Organizational

  7. Joint Force Quarterly. Number 4, Spring 1994

    Science.gov (United States)

    1994-05-01

    Littoral Warfare Joint Operations in the Civil War World War II Campaigns Page 2 - no folio P H O T O C R E D I T S The reproduction of the portrait of...destruction of their cities and two atomic bombs, until they were given guarantees on the survival of the emperor . This was a moral issue of such great...The Penguin Encyclopedia of Modern Warfare by Kenneth Macksey and William Woodhouse 30 JFQ / Spring 1994 strict arms control regime in a fiscally con

  8. Navy Perspective on Joint Force Interdependence

    Science.gov (United States)

    2015-01-01

    force, we are committed to revitalizing our skills as America’s mobile, forward-engaged “away team” and “first responders.” Building and maintaining...between themselves and with other global maritime partners. The Services writ large are not unfa- miliar with the notion of cross-domain synergy

  9. Enhancing Army Joint Force Headquarters Capabilities

    Science.gov (United States)

    2010-01-01

    Ad hoc (Army) 2004–2005 MNSTC-I SSTR CENTCOM Ad hoc (Army) 2004-2005 JTF-G8/ DNC /RNC HD/CS NORTHCOM Ad hoc (Army) x 3 2004 JTF-515 SSTR PACOM 2004...AFIC = Armed Forces Inaugural Committee; CENTCOM = Central Command; DNC = Democratic National Committee; EUCOM = European Command; FSSG = Fleet

  10. A New CT Method for Assessing 3D Movements in Lumbar Facet Joints and Vertebrae in Patients before and after TDR

    Directory of Open Access Journals (Sweden)

    Per Svedmark

    2015-01-01

    Full Text Available This study describes a 3D-CT method for analyzing facet joint motion and vertebral rotation in the lumbar spine after TDR. Ten patients were examined before and then three years after surgery, each time with two CT scans: provoked flexion and provoked extension. After 3D registration, the facet joint 3D translation and segmental vertebral 3D rotation were analyzed at the operated level (L5-S1 and adjacent level (L4-L5. Pain was evaluated using VAS. The median (±SD 3D movement in the operated level for the left facet joint was 3.2 mm (±1.9 mm before and 3.5 mm (±1.7 mm after surgery and for the right facet joint was 3.0 mm (±1.0 mm before and 3.6 mm (±1.4 mm after surgery. The median vertebral rotation in the sagittal plane at the operated level was 5.4° (±2.3° before surgery and 6.8° (±1.7° after surgery and in the adjacent level was 7.7° (±4.0° before and 9.2° (±2.7° after surgery. The median VAS was reduced from 6 (range 5–8 to 3 (range 2–8 in extension and from 4 (range 2–6 to 2 (range 1–3 in flexion.

  11. MRI-guided focused ultrasound (MRgFUS) to treat facet joint osteoarthritis low back pain - case series of an innovative new technique

    Energy Technology Data Exchange (ETDEWEB)

    Weeks, Evan M.; Platt, Michael W. [St Mary' s Hospital, Imperial College Healthcare NHS Trust, Department of Anaesthesia and Pain Medicine, London (United Kingdom); Gedroyc, Wladyslaw [St Mary' s Hospital, Imperial College Healthcare NHS Trust, Department of Radiology, London (United Kingdom)

    2012-12-15

    To evaluate the safety and efficacy of magnetic resonance-guided focused ultrasound (MRgFUS) to treat facet joint osteoarthritis pain. Patients with a positive response to facet joint interventions were recruited from Pain and Spinal Clinics. Treatments were performed at the levels of pain according to symptomatology, previous invasive treatment and MRI grading of facet joint osteoarthritis. Both safety and efficacy data were collected. Pain palliation was evaluated using a validated pain numerical rating scale (NRS), Oswestry disability questionnaire (ODQ), Brief Pain Inventory (BPI) and the EuroQol (EQ-5D) health state score Eighteen patients were treated. There were no major adverse events. At 6/12 we found a reduction in both the NRS (average/worst) pain scores (60.2 %/51.2 %). This was associated with 45.9 % improvement in the ODQ score and 61.9 % reduction in the BPI interference score. We observed an improvement in the EuroQol (EQ-5D) health state score based on UK coefficients of +0.379 (0.317 to 0.696). Our phase I observational pilot study has evaluated an innovative new technique that is both non-invasive and radiation free. It is the first description of this procedure in the literature. In all patients the technique was safe, free of complications, effective and well tolerated. (orig.)

  12. Force-State Characterization of Struts Using Pinned Joints

    Directory of Open Access Journals (Sweden)

    Brook D. Ferney

    1997-01-01

    Full Text Available As part of a research effort to study the microgravity dynamics of a truss with pinned joints, a single strut with a single clevis-tang pinned joint was characterized. Experimental data was collected using a force-state mapping technique. The strut was subjected to axial dynamic loads and the response of the strut was measured. The force-state map aids visualization of the strut dynamics. Finite element modeling of the response was explored. An example is presented that uses a method of manual determination of the finite element model parameters. The finite element model results correspond well with the measured strut response.

  13. Joint Force Quarterly. Number 34, Spring 2003

    Science.gov (United States)

    2003-07-01

    Trevor J. Bender • Drew A. Bennett • Sumner Benson • Alvin H. Bernstein • Richard K. Betts Stephen Biddle • Price T. Bingham • Hans Binnendijk • James R...the RAND Corporation and author of The Icarus Syndrome , an analysis of airpower theory in the evolution of the Air Force. Keeping the Strategic Flame...Brian M. Lewis • William H. Lewis • Martin C. Libicki • Joseph I. Lieberman • Charles D. Link Brian M. Linn • Thomas C. Linn • James R. Locher III • John

  14. Pan-regional (cervico-thoraco-lumbo-sacral spinal epidural abscess with multi-level discitis, vertebral body osteomyelitis and facet joint septic arthritis: complete resolution with non-operative management

    Directory of Open Access Journals (Sweden)

    Appukutty Manickam, MRCS

    2014-12-01

    Conclusion: Even pan-regional CTLS SEA with multi-level discitis, vertebral body osteomyelitis and facet joint septic arthritis can be managed non-operatively. A complete clinical and radiological resolution can be achieved with antibiotics alone.

  15. Joint Force Quarterly. Issue 77, 2nd Quarter 2015

    Science.gov (United States)

    2015-04-01

    Based Intelligence: Revolutionizing Military Intelligence Analysis By Chandler P. Atwood 34 The Defense Innovation Initiative: The Importance of...activity-based intelligence” within the U.S. Air Force, and potentially across the joint force. Following the recent DOD Innovation Initiative...the consen- sus forecasts of experts and that is close to being available in real time. A fairly new and emerging field, the ethics of big data has

  16. Joint forces and torques when walking in shallow water.

    Science.gov (United States)

    Orselli, Maria Isabel Veras; Duarte, Marcos

    2011-04-01

    This study reports for the first time an estimation of the internal net joint forces and torques on adults' lower limbs and pelvis when walking in shallow water, taking into account the drag forces generated by the movement of their bodies in the water and the equivalent data when they walk on land. A force plate and a video camera were used to perform a two-dimensional gait analysis at the sagittal plane of 10 healthy young adults walking at comfortable speeds on land and in water at a chest-high level. We estimated the drag force on each body segment and the joint forces and torques at the ankle, knee, and hip of the right side of their bodies using inverse dynamics. The observed subjects' apparent weight in water was about 35% of their weight on land and they were about 2.7 times slower when walking in water. When the subjects walked in water compared with walking on land, there were no differences in the angular displacements but there was a significant reduction in the joint torques which was related to the water's depth. The greatest reduction was observed for the ankle and then the knee and no reduction was observed for the hip. All joint powers were significantly reduced in water. The compressive and shear joint forces were on average about three times lower during walking in water than on land. These quantitative results substantiate the use of water as a safe environment for practicing low-impact exercises, particularly walking.

  17. Joint Force Interdependence for a Fiscally Constrained Future

    Science.gov (United States)

    2013-03-01

    Army 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Dr. Richard Meinhart ...Joint Force Interdependence For A Fiscally Constrained Future by Colonel Daniel P. Ray United States Army ...United States Army War College Class of 2013 DISTRIBUTION STATEMENT: A Approved for Public Release Distribution is Unlimited

  18. Determination and optimization of joint torques and joint reaction forces in therapeutic exercises with elastic resistance.

    Science.gov (United States)

    Biscarini, Andrea

    2012-01-01

    A model has been developed to definitively characterize the resistance properties and the joint loading (i.e., shear and compressive components of the joint reaction force) in single-joint exercises with ideal elastic bands. The model accounts for the relevant geometric and elastic properties of the band, the band pre-stretching, and the relative positioning among the joint center of rotation and the fixation points of the band. All the possible elastic torque profiles of ascending-descending, descending, or ascending type were disclosed in relation to the different ranges of joint angles. From these results the elastic resistance setting that best reproduces the average-user's knee extensor torque in maximal isometric/isokinetic efforts was determined. In this optimized setting, the shear tibiofemoral reaction force corresponding to an anterior (posterior) tibial displacement was 65% smaller than (nearly the same as) that obtained in a cam-equipped leg-extension equipment for equal values of resistance torque peak, whereas the compressive tibiofemoral reaction force was 22% higher. Compared to a weight-stack leg-extension equipment, an elastic resistance optimized setting has the potential to give a more effective quadriceps activation across the range of motion, and greatly reduces the anterior cruciate ligament strain force, which represents the main drawback of existing open kinetic-chain knee-extension exercises.

  19. Static and dynamic mechanics of the temporomandibular joint: plowing forces, joint load and tissue stress.

    Science.gov (United States)

    Nickel, J; Spilker, R; Iwasaki, L; Gonzalez, Y; McCall, W D; Ohrbach, R; Beatty, M W; Marx, D

    2009-08-01

    OBJECTIVES - To determine the combined effects 1) of stress-field aspect ratio and velocity and compressive strain and 2) joint load, on temporomandibular joint (TMJ) disc mechanics. SETTING AND SAMPLE POPULATION - Fifty-two subjects (30 female; 22 male) participated in the TMJ load experiments. MATERIAL AND METHODS - In the absence of human tissue, pig TMJ discs were used to determine the effects of variables 1) on surface plowing forces, and to build a biphasic finite element model (bFEM) to test the effect of human joint loads and 2) on tissue stresses. In the laboratory, discs received a 7.6 N static load via an acrylic indenter before cyclic movement. Data were recorded and analysed using anova. To determine human joint loads, Research Diagnostic Criteria calibrated investigators classified subjects based on signs of disc displacement (DD) and pain (+DD/+pain, n = 18; +DD/-pain, n = 17; -DD/-pain, n = 17). Three-dimensional geometries were produced for each subject and used in a computer model to calculate joint loads. RESULTS - The combined effects of compressive strain, and aspect ratio and velocity of stress-field translation correlated with plowing forces (R(2) = 0.85). +DD/-pain subjects produced 60% higher joint loads (ANOVA, p dynamic variables of the stress-field and subject-dependent joint load significantly affect disc mechanics.

  20. The relationship between the prevalance and size of lumbar ossified ligamentum flavum and the presence and degree of facet joint degeneration

    Energy Technology Data Exchange (ETDEWEB)

    Ergun, Tarkan, E-mail: tarkanergun@yahoo.com [Baskent University School Medicine, Departments of Radiology, Alanya Teaching and Medical Research Center, 07400 Alanya, Antalya (Turkey); Lakadamyali, Hatice, E-mail: adviyesalman@yahoo.com [Baskent University School Medicine, Departments of Radiology, Alanya Teaching and Medical Research Center, 07400 Alanya, Antalya (Turkey)

    2012-11-15

    Objectives: To investigate whether there is any relationship between the prevalence and the dimension of OLF and the presence and degree of facet joint degeneration. In addition, it revealed the prevalence and distribution of lumbar OLF with regard to age and spinal levels. Methods: The stone protocol abdominal CT images of 114 patients were retrospectively analyzed. Presence of OLF, degenerative changes in the posterior vertebral elements was evaluated on axial CT images and incidence for each finding was determined. Additionally, the degree of facet joint degeneration and size of OLF was evaluated and recorded. All findings were also grouped based on age and lumbar level. Results: OLF has been observed in 40 (35%) individuals at 76 (13%) lumbar levels. OLF has been most frequently encountered at the upper lumbar levels. Its frequency and size showed correlation to increased age. Frequency of OLF correlated with the presence of degenerative changes of in the posterior elements (p < 0.001). There was an association between the OLF size and the presence (p = 0.001) and degree of the degeneration in the posterior elements. There was no lumbar level case where the degree of OLF would lead to enough narrowing to be symptomatic. Conclusions: OLF prevalence and sizes increase parallel to age. Posterior elements' degenerative changes facilitate OLF development. A close relation exists between OLF size and facet joint degeneration. A direct relationship exists between OLF size and the degree of posterior elements degeneration. It is highly probable for lumbar level OLF size to be insufficient to cause any symptoms.

  1. A review of percutaneous techniques for low back pain and neuralgia: current trends in epidural infiltrations, intervertebral disk and facet joint therapies.

    Science.gov (United States)

    Filippiadis, Dimitrios K; Kelekis, Alexis

    2016-01-01

    Low back pain and neuralgia due to spinal pathology are very common symptoms debilitating numerous patients with peak prevalence at ages between 45 and 60 years. Intervertebral discs and facet joints act as pain sources in the vast majority of the cases. Diagnosis is based on the combination of clinical examination and imaging studies. Therapeutic armamentarium for low back pain and neuralgia due to intervertebral discs and/or facet joints includes conservative therapy, injections, percutaneous therapeutic techniques and surgical options. Percutaneous, therapeutic techniques are imaging-guided, minimally invasive treatments which can be performed as outpatient procedures. In cases of facet joint syndrome, they include, apart from injections, neurolysis with radiofrequency/cryoablation, MR-guided high-intensity focused ultrasound and percutaneous fixation techniques. In case of discogenic pain, apart from infiltrations, therapeutic techniques can be classified in to two main categories: decompression (mechanical, thermal, chemical) techniques and biomaterials implantation/disc cell therapies. Strict sterility measures are a prerequisite and should include extensive local sterility and antibiotic prophylaxis. This article will report clinical and imaging findings for each pathology type and the association with treatment decision. In addition, we will describe in detail all possible treatment techniques for low back pain and neuralgia, and we will report recently published results of these techniques summarizing the data concerning safety and effectiveness as well as the level of evidence. Finally, we will try to provide a rational approach for the therapy of low back pain and neuralgia by means of minimally invasive imaging-guided percutaneous techniques.

  2. Quantifying plyometric intensity via rate of force development, knee joint, and ground reaction forces.

    Science.gov (United States)

    Jensen, Randall L; Ebben, William P

    2007-08-01

    Because the intensity of plyometric exercises usually is based simply upon anecdotal recommendations rather than empirical evidence, this study sought to quantify a variety of these exercises based on forces placed upon the knee. Six National Collegiate Athletic Association Division I athletes who routinely trained with plyometric exercises performed depth jumps from 46 and 61 cm, a pike jump, tuck jump, single-leg jump, countermovement jump, squat jump, and a squat jump holding dumbbells equal to 30% of 1 repetition maximum (RM). Ground reaction forces obtained via an AMTI force plate and video analysis of markers placed on the left hip, knee, lateral malleolus, and fifth metatarsal were used to estimate rate of eccentric force development (E-RFD), peak ground reaction forces (GRF), ground reaction forces relative to body weight (GRF/BW), knee joint reaction forces (K-JRF), and knee joint reaction forces relative to body weight (K-JRF/BW) for each plyometric exercise. One-way repeated measures analysis of variance indicated that E-RFD, K-JRF, and K-JRF/BW were different across the conditions (p 0.05). Results indicate that there are quantitative differences between plyometric exercises in the rate of force development during landing and the forces placed on the knee, though peak GRF forces associated with landing may not differ.

  3. Critical Values of Facet Joint Angulation and Tropism in the Development of Lumbar Degenerative Spondylolisthesis: An International, Large-Scale Multicenter Study by the AOSpine Asia Pacific Research Collaboration Consortium

    Science.gov (United States)

    Samartzis, Dino; Cheung, Jason Pui Yin; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D. K.; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Goss, Ben; Sham, Phoebe; Williams, Richard

    2015-01-01

    Study Design  An international, multicenter cross-sectional image-based study performed in 33 institutions in the Asia Pacific region. Objective  The study addressed the role of facet joint angulation and tropism in relation to L4–L5 degenerative spondylolisthesis (DS). Methods  The study included 349 patients (63% females; mean age: 61.8 years) with single-level DS; 82 had no L4–L5 DS (group A) and 267 had L4–L5 DS (group B). Axial computed tomography and magnetic resonance imaging were utilized to assess facet joint angulations and tropism (i.e., asymmetry between facet joint angulations) between groups. Results  There was a statistically significant difference between group A (left mean: 46.1 degrees; right mean: 48.2 degrees) and group B (left mean: 55.4 degrees; right mean: 57.5 degrees) in relation to bilateral L4–L5 facet joint angulations (p < 0.001). The mean bilateral angulation difference was 7.4 and 9.6 degrees in groups A and B, respectively (p = 0.025). A critical value of 58 degrees or greater significantly increased the likelihood of DS if unilateral (adjusted OR: 2.5; 95% CI: 1.2 to 5.5; p = 0.021) or bilateral facets (adjusted OR: 5.9; 95% CI: 2.7 to 13.2; p < 0.001) were involved. Facet joint tropism was found to be relevant between 16 and 24 degrees angulation difference (adjusted OR: 5.6; 95% CI: 1.2 to 26.1; p = 0.027). Conclusions  In one of the largest studies assessing facet joint orientation in patients with DS, greater sagittal facet joint angulation was associated with L4-L5 DS, with a critical value of 58 degrees or greater increasing the likelihood of the condition for unilateral and bilateral facet joint involvement. Specific facet joint tropism categories were noted to be associated with DS. PMID:27433424

  4. Forced-air warming discontinued: periprosthetic joint infection rates drop

    Directory of Open Access Journals (Sweden)

    Scott D. Augustine

    2017-06-01

    Full Text Available Several studies have shown that the waste heat from forced-air warming (FAW escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002. The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs.

  5. Joint Force Quarterly. Issue 59, 4th Quarter 2010

    Science.gov (United States)

    2010-10-01

    casualties. From 2001 to 2006, numerous seismic shifts occurred in the regional and global strategic environment that moved the balance of power...Act of 1986 sought to meld the DOD tectonic divide between operational and administrative control of military forces. The same kind of studied...and rotor lead plates for 30-kilowatt generators. Another high-strength rare earth magnesium alloy, known as “BM25,” which was jointly devel- oped

  6. Exercise Design for the Joint Force 2020 Brigade Combat Team

    Science.gov (United States)

    2012-03-22

    actual combat. EXERCISE DESIGN FOR THE JOINT FORCE 2020 BRIGADE COMBAT TEAM In the 21st century, we do not have the luxury of deciding...businesses, painting contractors, gas stations and garages, and auto dealerships. There should also be banks and money lenders, restaurants and cafes... hotels , internet cafes, public utilities and associated infrastructure, as well as newspapers and radio stations. In addition to the portrayal of

  7. Contingency Forces in the Year 2020 Optimizing Joint Warfighting

    Science.gov (United States)

    1993-04-22

    Operation Desert One: (Operation Rice Bowl): August 1980 Iranian hostage rescue mission. 3. Operation Urgent Fury: 25 October 1983 Invasion of Grenada...already on casualty lists, and U.S. citizens and U.S. industrial facilities were being held hostage for 1xiternational leverage. Chemical weapons had been...operations units, Naval units, or commands such as the Joint Special Operations Ccawand-- JSOC ) is just as appropriate for contingency forces. Such

  8. Influence of joint models on lower-limb musculo-tendon forces and three-dimensional joint reaction forces during gait.

    Science.gov (United States)

    Dumas, Raphaël; Moissenet, Florent; Gasparutto, Xavier; Cheze, Laurence

    2012-02-01

    Several three-dimensional (3D) lower-limb musculo-skeletal models have been developed for gait analysis and different hip, knee and ankle joint models have been considered in the literature. Conversely to the influence of the musculo-tendon geometry, the influence of the joint models--i.e. number of degrees of freedom and passive joint moments--on the estimated musculo-tendon forces and 3D joint reaction forces has not been extensively examined. In this paper musculo-tendon forces and 3D joint reaction forces have been estimated for one subject and one gait cycle with nine variations of a musculoskeletal model and outputs have been compared to measured electromyographic signals and knee joint contact forces. The model outputs are generally in line with the measured signals. However, the 3D joint reaction forces were higher than published values and the contact forces measured for the subject. The results of this study show that, with more degrees of freedom in the model, the musculo-tendon forces and the 3D joint reaction forces tend to increase but with some redistribution between the muscles. In addition, when taking into account passive joint moments, the 3D joint reaction forces tend to decrease during the stance phase and increase during the swing phase. Although further investigations are needed, a five-degree-of-freedom lower-limb musculo-skeletal model with some angle-dependent joint coupling and stiffness seems to provide satisfactory musculo-tendon forces and 3D joint reaction forces.

  9. Virtual reality imaging with real-time ultrasound guidance for facet joint injection: a proof of concept.

    Science.gov (United States)

    Clarke, Collin; Moore, John; Wedlake, Christopher; Lee, Donald; Ganapathy, Su; Salbalbal, Maher; Wilson, Timothy; Peters, Terry; Bainbridge, Daniel

    2010-05-01

    Facet interventions continue to be used in pain management. Computed tomographic (CT) images can be registered into a virtual world that includes images generated by an ultrasound (US) probe tracked in real time, permitting guidance of tracked needles. We acquired CT-generated 3-dimensional (3D) images of 2 models and a cadaver. Three-dimensional representations of a US probe and needle were generated. A magnetic system tracked the needle and US probe. Using the US, 3D CT images were registered to the model/cadaver. Images were fused on a single interface. Facet injections were performed in the models and cadaver with radio-opaque markers. A postprocedure CT image determined appropriate placement. The virtual reality system described demonstrates technical innovations that may lead to future advancements in the area of percutaneous interventions in the management of pain.

  10. Redefining Joint Fires Service Functions to Better Support Joint Force Operations

    Science.gov (United States)

    2012-06-01

    Chairman of Joint Chiefs of Staff (CJCS) must review service roles, missions, and functions every three years. Admiral Crowe , the first CJCS to conduct...3 Ibid. 4 William J. Crowe . Roles and Functions of the Armed Force, A Report to the Secretary of Defense (Washington, DC: Office of the Chairman of...tactical-level fires. The opinion espoused by AF Chief of Staff Gen Merrill McPeak was especially provocative. Gen McPeak opined that modern warfare

  11. Revisiting the Force-Joint Angle Relationship After Eccentric Exercise.

    Science.gov (United States)

    Welsh, Molly C; Allen, David L; Batliner, Matthew E; Byrnes, William C

    2015-12-01

    The purpose of this study was to evaluate force-angle curve fitting techniques pre-eccentric exercise, quantify changes in curve characteristics postexercise, and examine the relationship between curve changes and markers of muscle damage. Fourteen males unaccustomed to eccentric exercise performed 60 eccentric muscle actions of the elbow flexors. Maximal voluntary isometric force was measured throughout a range of angles pre- (Pre1 and Pre2), immediately post (IP), and 1, 2, 4, and 7 days postexercise. Force-angle curves for each visit were constructed using second-order polynomials. Changes in curve characteristics (optimal angle, peak force, curve height), range of motion, soreness, and creatine kinase activity were quantified. Optimal joint angle and force at optimal angle were significantly correlated from Pre1 to Pre2 (ICC = 0.821 and 0.979, respectively). Optimal angle was significantly right shifted (p = 0.035) by 10.4 ± 12.9° from Pre2 to IP and was restored by 1 day post exercise. Interestingly, the r value for curve fit was significantly decreased (p exercise (r = 0.750). Curve height was significantly decreased (39%) IP and restored to pre-exercise height by 4 days postexercise. There was no correlation between optimal angle or curve height and other damage markers. In conclusion, force-angle relationships can be accurately described using second-order polynomials. After eccentric exercise, the force-angle curve is flattened and shifted (downward and rightward), but these changes are not correlated to other markers of muscle damage. Changes in the force-angle relationship are multifaceted, but determining the physiological significance of these changes requires further investigation.

  12. Temporomandibular joint forces measured at the condyle of Macaca arctoides.

    Science.gov (United States)

    Boyd, R L; Gibbs, C H; Mahan, P E; Richmond, A F; Laskin, J L

    1990-06-01

    Forces were measured at the articular surface of the temporomandibular joint (TMJ) condyle in two stump-tail monkeys (Macaca arctoides) during chewing, incisal biting, and drinking and also during aggressive behaviors. Force was measured with a thin piezoelectric foil transducer, which was cemented over the anterior and superior surfaces of the condyle. Wires from the upper and lower surfaces of the foil were insulated between two layers of Teflon tape and run subcutaneously to a telemetry unit, which was implanted in the upper back. Force applied across the foil by the condyle was detected by the telemetry unit and transmitted to an FM radio receiver outside the animal. The FM signals were received and demodulated, and a signal proportional to the force applied between the condyle and the TMJ fossa was displayed on a chart recorder. Data were collected over an 8-day period. The animals were not constrained. The TMJ was found to be load bearing. The greatest force of 39.0 lb (17.7 kg) was measured during feisty vocal aggression. Forces ranged as high as 34.5 lb (15.7 kg) during chewing and 28.5 lb (13.0 kg) during incisal biting. Forces were greater on the working (food) side than on the nonworking (balancing) side by average ratios of 1.4 to 2.6. A large unilateral interference at the most distal molar greatly disturbed chewing. It reduced TMJ forces by 50% or more, and the monkey refused to chew on the side opposite the interference.

  13. Joint Concept Development and Experimentation: A Force Development Perspective

    Science.gov (United States)

    2012-02-01

    Defence R&D Canada Centre for Operational Research and Analysis Warfare Centre Science Team Canadian Forces Warfare Centre Joint Concept...Scientist, DRDC CORA Defence R&D Canada – Centre for Operational Research and Analysis (CORA) © Her Majesty the Queen in Right of Canada, as...apportés, le présent rapport s’inspire de l’examen de la documentation scientifique pour présenter les meilleurs pratiques en matière de développement

  14. The Effect of Foot Progression Angle on Knee Joint Compression Force during Walking

    DEFF Research Database (Denmark)

    Baldvinsson, Henrik Koblauch; Heilskov-Hansen, Thomas; Alkjær, Tine

    2013-01-01

    compression force increased during EFR and the lateral knee joint compartment compression force increased during IFR. The increases in joint loads may be a result of increased knee flexion angles. Further these data suggest that the frontal plane knee joint moment is not a valid surrogate measure for knee...

  15. The Effect of Foot Progression Angle on Knee Joint Compression Force during Walking

    DEFF Research Database (Denmark)

    Baldvinsson, Henrik Koblauch; Heilskov-Hansen, Thomas; Alkjær, Tine

    2013-01-01

    compression force increased during EFR and the lateral knee joint compartment compression force increased during IFR. The increases in joint loads may be a result of increased knee flexion angles. Further these data suggest that the frontal plane knee joint moment is not a valid surrogate measure for knee...

  16. Faceted Search

    CERN Document Server

    Tunkelang, Daniel

    2009-01-01

    We live in an information age that requires us, more than ever, to represent, access, and use information. Over the last several decades, we have developed a modern science and technology for information retrieval, relentlessly pursuing the vision of a "memex" that Vannevar Bush proposed in his seminal article, "As We May Think." Faceted search plays a key role in this program. Faceted search addresses weaknesses of conventional search approaches and has emerged as a foundation for interactive information retrieval. User studies demonstrate that faceted search provides more

  17. 腰椎小关节内注射倍他米松治疗腰椎小关节病变所致慢性腰痛%Effects of Injecting Betamethasone to Lumbar Facet Joints on Patients with Chronic Low-Back Pain from the Disfunction of Lumbar Facet Joints

    Institute of Scientific and Technical Information of China (English)

    张光明; 唐坤; 陈俊峰

    2011-01-01

    目的:评估C型臂X光机引导下腰椎小关节内注射倍他米松对腰椎小关节病变所致慢性腰痛的疗效.方法:腰痛时间长于3个月,腰痛症状和体征符合腰椎小关节病变临床表现,经影像学和小关节内注射局麻药诊断性治疗后诊断为腰椎小关节病变的40例患者随机分为小关节注射组(n=20)和消炎镇痛药组(n=20).小关节注射组患者在C型臂X光机引导下行腰椎小关节内注射倍他米松,消炎镇痛药组患者口服双氯芬酸钠.腰痛程度采用视觉模拟评分法(visual analogue scale,VAS)评分.观察时间点定为治疗前(T0)和治疗后3个月(T1).主要观察患者的生命体征和VAS评分.根据治疗过程中VAS改善程度统计疗效(分为显效、有效和无效).结果:治疗后3个月注射组总有效率为92%,消炎镇痛药组总有效率为46%;注射组显效率为74%,消炎镇痛药组显效率为26%.注射组的总有效率和显效率均显著高于消炎镇痛药组(P<0.01).结论:C型臂X光机引导下腰椎小关节内注射倍他米松能有效缓解腰椎小关节病变所致慢性腰痛,疗效优于口服药物治疗.%Objective:To investigate the effects of injecting Betamethasone to lumbar facet joints under the guidance of C-arm X-ray machine on patients with chronic low-back pain from the disfunction of lumbar facet joints. Methods: A total of 40 patients with low-back pain from the disfunction of lumbar facet joints more than 3 months were enrolled in this study. The patients were randomly divided into 2 groups(n = 20, each). The injection group received the injecting Betamethasone to lumbar facet joints under the guidance of C-arm X-ray machine; while the medcine group received taking diclofenac sodium. The vital signs and visual analogue scale were recorded before the treatment(T0) and 3 months after the treatment(Ti ). The effects of treatment were evaluated according to the changes of visual analogue scale (VAS) and were divided into

  18. Muscular response to physiologic tensile stretch of the caprine c5/6 facet joint capsule: dynamic recruitment thresholds and latencies.

    Science.gov (United States)

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Cavanaugh, John M

    2011-11-01

    This study examined the cervical muscle response to physiologic, high-rate (100 mm/s) tensile facet joint capsule (FJC) stretch. Six in-vivo caprine C5/6 FJC preparations were subjected to an incremental tensile loading paradigm. EMG activity was recorded from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels; and from the sternomastoid (SM) and longus colli (LC) muscle groups bilaterally at the C5/6 level; during FJC stretch. Capsule load during the displacement applications was recorded via a miniature load cell, and 3D capsule strains (based on stereoimaging of an array of markers on the capsule surface) were reconstructed using finite element methods. EMG traces from each muscle were examined for onset of muscular activity. Capsule strains and loads at the time of EMG onset were recorded for each muscle, as was the time from the onset of FJC stretch to the onset of muscle activity. All muscles were responsive to physiologic high-rate FJC stretch. The deep muscles (MF and LC) were recruited at significantly smaller capsule loads and onset latencies than the superficial muscles (TR and SM). MF activation strain was significantly smaller than LC and TR activation strains. These data were also compared to previously published low-rate data. MF was the first muscle group to be recruited regardless of the activation criterion under consideration (i.e. strain, load, or latency) or the rate of FJC stretch. LC recruitment occurred significantly sooner under high-rate vs. low-rate FJC stretch. The results of this study provide further evidence of extensive ligamento-muscular reflex pathways between the FJC and the cervical musculature, which are responsive to both low-rate and high-rate FJC stretch. These data add to our knowledge of the dynamic response of paraspinal muscles relative to facet joint motion and provide a unique contribution to enhance the precision of computer-simulated impacts.

  19. Fluoroscopic cervical epidural injections in chronic axial or disc-related neck pain without disc herniation, facet joint pain, or radiculitis

    Directory of Open Access Journals (Sweden)

    Manchikanti L

    2012-07-01

    Full Text Available Laxmaiah Manchikanti, Kimberly A Cash, Vidyasagar Pampati, Yogesh MallaPain Management Center of Paducah, Paducah, KY, USABackground: While chronic neck pain is a common problem in the adult population, with a typical 12-month prevalence of 30%–50%, there is a lack of consensus regarding its causes and treatment. Despite limited evidence, cervical epidural injections are one of the commonly performed nonsurgical interventions in the management of chronic neck pain.Methods: A randomized, double-blind, active, controlled trial was conducted to evaluate the effectiveness of cervical interlaminar epidural injections of local anesthetic with or without steroids for the management of chronic neck pain with or without upper extremity pain in patients without disc herniation, radiculitis, or facet joint pain.Results: One hundred and twenty patients without disc herniation or radiculitis and negative for facet joint pain by means of controlled diagnostic medial branch blocks were randomly assigned to one of two treatment groups, ie, injection of local anesthetic only (group 1 or local anesthetic mixed with nonparticulate betamethasone (group 2. The primary outcome of significant pain relief and improvement in functional status (≥50% was demonstrated in 72% of group 1 and 68% of group 2. The overall average number of procedures per year was 3.6 in both groups with an average total relief per year of 37–39 weeks in the successful group over a period of 52 weeks.Conclusion: Cervical interlaminar epidural injections of local anesthetic with or without steroids may be effective in patients with chronic function-limiting discogenic or axial pain.Keywords: chronic neck pain, cervical disc herniation, cervical discogenic pain, cervical epidural injections, epidural steroids, local anesthetics

  20. The Effect of Foot Progression Angle on Knee Joint Compression Force during Walking

    DEFF Research Database (Denmark)

    Baldvinsson, Henrik Koblauch; Heilskov-Hansen, Thomas; Alkjær, Tine

    2013-01-01

    compression force increased during EFR and the lateral knee joint compartment compression force increased during IFR. The increases in joint loads may be a result of increased knee flexion angles. Further these data suggest that the frontal plane knee joint moment is not a valid surrogate measure for knee......It is unclear how rotations of the lower limb affect the knee joint compression forces during walking. Increases in the frontal plane knee moment have been reported when walking with internally rotated feet and a decrease when walking with externally rotated feet. The aim of this study...... was to investigate the knee joint compressive forces during walking with internal, external and normal foot rotation and to determine if the frontal plane knee joint moment is an adequate surrogate for the compression forces in the medial and lateral knee joint compartments under such gait modifications. Ten healthy...

  1. PRELIMINARY STUDIES OF RIVETED JOINTS AT FEED FORCE

    Directory of Open Access Journals (Sweden)

    Radosław Bielawski

    2015-08-01

    Full Text Available The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test one type of glass fabric was used (Interglas 92140 from which two types of composite samples were prepared. In each sample the same type of fiber with the same fiber orientation – 3 layers - was used. The samples had dimensions of 100×100 mm and thickness of approximately 1 mm. The composite probes were located in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 16 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fibre orientations and the value of feed force, damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

  2. The Standing Joint Force Headquarters Plan-Does It Go Far Enough?

    Science.gov (United States)

    2010-07-26

    humanitarian relief effort in Bangladesh following Cyclone Marian, the PACOM DJTFAC deployed in support of the III MEF. A successful relief operation...Putnam’s Sons, 2002. 67 Cole, Ronald H., “Grenada, Panama, and Haiti : Joint Operational Reform,” Joint Forces Quarterly, Autumn/Winter 1998-99...2002. Smith, Matthew , Major (USAF), “Successfully Developing Future Joint Leaders,” Norfolk, VA: Joint Forces Staff College, 2005. Stewart

  3. Lower limb joint forces during walking on the level and slopes at different inclinations.

    Science.gov (United States)

    Alexander, Nathalie; Schwameder, Hermann

    2016-03-01

    Sloped walking is associated with an increase of lower extremity joint loading compared to level walking. Therefore, the aim of this study was to analyse lower limb joint compression forces as well as tibiofemoral joint shear forces during sloped walking at different inclinations. Eighteen healthy male participants (age: 27.0 ± 4.7 years, height: 1.80 ± 0.05 m, mass: 74.5 ± 8.2 kg) were asked to walk at a pre-set speed of 1.1m/s on a ramp (6 m × 1.5 m) at the slopes of -18°, -12°, -6°, 0°, 6°, 12° and 18°. Kinematic data were captured with a twelve-camera motion capture system (Vicon). Kinetic data were recorded with two force plates (AMTI) imbedded into a ramp. A musculoskeletal model (AnyBody) was used to compute lower limb joint forces. Results showed that downhill walking led to significantly increased hip, tibiofemoral and patellofemoral joint compression forces (pjoint compression forces (pjoint compression forces with increasing inclination (pligament could not be supported in the current study, since anterior tibiofemoral joint shear forces did not increase with the gradient. Due to diverse tibiofemoral joint shear force patterns in the literature, results should be treated with caution in general. Finally, lower limb joint force analyses provided more insight in the structure loading conditions during sloped walking than joint moment analyses.

  4. GEORG-SCHMORL-PRIZE OF THE GERMAN SPINE SOCIETY (DWG) 2016: Comparison of in vitro osteogenic potential of iliac crest and degenerative facet joint bone autografts for intervertebral fusion in lumbar spinal stenosis.

    Science.gov (United States)

    Geurts, Jeroen; Ramp, Daniela; Schären, Stefan; Netzer, Cordula

    2017-05-01

    The promotion of spinal fusion using bone autografts is largely mediated by the osteoinductive potential of progenitors/mesenchymal stem cells (MSC) that reside in the marrow spaces of cancellous bone. Iliac crest is the common autograft donor site, but its use presents an increased risk for donor site pain, morbidity and infection. Degenerative bone samples harvested during facetectomy might provide an alternative viable source of osteoinductive autografts. In this study, we conducted an intra-individual comparison of the osteogenic potential of isolated low passage MSC from both sources. Iliac crest and degenerative facet joints were harvested from eight consecutive patients undergoing transforaminal lumbar interspinal fusion due to lumbar spinal stenosis. MSC were isolated by collagenase digestion, selected by plastic adherence and minimally expanded for downstream assays. Clonogenic and osteogenic potential was evaluated by colony formation assays in control and osteogenic culture medium. Osteogenic properties, including alkaline phosphatase (ALP) induction, matrix mineralization and type I collagen mRNA and protein expression were characterized using quantitative histochemical staining and reverse transcription PCR. Spontaneous adipogenesis was analysed by adipocyte enumeration and gene expression analysis of adipogenic markers. Average colony-forming efficiency in osteogenic medium was equal between iliac crest (38 ± 12%) and facet joint (36 ± 11%). Osteogenic potential at the clonal level was 55 ± 26 and 68 ± 17% for iliac crest and facet joint MSC, respectively. Clonogenic and osteogenic potential were significantly negatively associated with donor age. Osteogenic differentiation led to significant induction of ALP activity in iliac crest (sixfold) and facet joint (eightfold) MSC. Matrix mineralization quantified by Alizarin red staining was increased by osteogenic differentiation, yet similar between both MSC sources. Protein expression of type

  5. Soft tissue balance changes depending on joint distraction force in total knee arthroplasty.

    Science.gov (United States)

    Nagai, Kanto; Muratsu, Hirotsugu; Matsumoto, Tomoyuki; Miya, Hidetoshi; Kuroda, Ryosuke; Kurosaka, Masahiro

    2014-03-01

    The influence of joint distraction force on intraoperative soft tissue balance was evaluated using Offset Repo-Tensor® for 78 knees that underwent primary posterior-stabilized total knee arthroplasty. The joint center gap and varus ligament balance were measured between osteotomized surfaces using 20, 40 and 60 lbs of joint distraction force. These values were significantly increased at extension and flexion as the distraction force increased. Furthermore, lateral compartment stiffness was significantly lower than medial compartment stiffness. Thus, larger joint distraction forces led to larger varus ligament balance and joint center gap, because of the difference in soft tissue stiffness between lateral and medial compartments. These findings indicate the importance of the strength of joint distraction force in the assessment of soft tissue balance, especially when using gap-balancing technique.

  6. The effect of foot progression angle on knee joint compression force during walking.

    Science.gov (United States)

    Koblauch, Henrik; Heilskov-Hansen, Thomas; Alkjær, Tine; Simonsen, Erik B; Henriksen, Marius

    2013-06-01

    It is unclear how rotations of the lower limb affect the knee joint compression forces during walking. Increases in the frontal plane knee moment have been reported when walking with internally rotated feet and a decrease when walking with externally rotated feet. The aim of this study was to investigate the knee joint compressive forces during walking with internal, external and normal foot rotation and to determine if the frontal plane knee joint moment is an adequate surrogate for the compression forces in the medial and lateral knee joint compartments under such gait modifications. Ten healthy males walked at a fixed speed of 4.5 km/h under three conditions: Normal walking, internally rotated and externally rotated. All gait trials were recorded by six infrared cameras. Net joint moments were calculated by 3D inverse dynamics. The results revealed that the medial knee joint compartment compression force increased during external foot rotation and the lateral knee joint compartment compression force increased during internal foot rotation. The increases in joint loads may be a result of increased knee flexion angles. Further, these data suggest that the frontal plane knee joint moment is not a valid surrogate measure for knee joint compression forces but rather indicates the medial- to-lateral load distribution.

  7. Are Standing Joint Task Force Headquarters the First Step in Transforming Cold War Formations?

    Science.gov (United States)

    2002-05-01

    and General Staff College, 1995. Connaughton , Richard M. "Organizing British Joint Rapid Reaction Forces." Joint Force Quarterly. Autumn 2000, pp. 87...Margaret Roth, and Caleb Baker. Operation Just Cause: The Storming of Panama. New York: Lexington Books, 1991. Dunn, Brian J. "Rethinking Army-Marine

  8. Facet analysis

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2013-01-01

    The facet-analytic paradigm is probably the most distinct approach to knowledge organization within Library and Information Science, and in many ways it has dominated what has be termed “modern classification theory”. It was mainly developed by S.R. Ranganathan and the British Classification Rese...

  9. Lumbar spine superior-level facet joint violations: percutaneous versus open pedicle screw insertion using intraoperative 3-dimensional computer-assisted navigation

    Institute of Scientific and Technical Information of China (English)

    Tian Wei; Xu Yunfeng; Liu Bo; Liu Yajun; He Da; Yuan Qiang; Lang Zhao

    2014-01-01

    Background Percutaneous pedicle screw use has a high rate of cranial facet joint violations (FVs) because of the facet joint being indirectly visualized.Computer-assisted navigation shows the anatomic structures clearly,and may help to lower the rate of FVs during pedicle screw insertion.This study used computed tomography (CT) to evaluate and compare the incidence of FVs between percutaneous and open surgeries employing computer-assisted navigation for the implantation of pedicle screw instrumentation during lumbar fusions.Methods A prospective study,including 142 patients having lumbar and lumbosacral fusion,was conducted between January 2013 and April 2014.All patients had bilateral posterior pedicle screw-rod instrumentation (top-loading screws) implanted by the same group of surgeons; intraoperative 3-dimensional computer navigation was used during the procedures.All patients underwent CT examinations within 6 months postoperation.The CT scans were independently reviewed by three reviewers blinded to the technique used.Results The cohort comprised 68 percutaneous and 74 open cases (136 and 148 superior-level pedicle screw placements,respectively).Overall,superior-level FVs occurred in 20 patients (20/142,14.1%),involving 27 top screws (27/284,9.5%).The percutaneous technique (7.4% of patients,3.7% of top screws) had a significantly lower violation rate than the open procedure (20.3% of patients,14.9% of top screws).The open group also had significantly more serious violations than did the percutaneous group.Both groups had a higher violation rate when the cranial fixation involved the L5.A 1-level open procedure had a higher violation rate than did the 2-and 3-level surgeries.Conclusions With computer-assisted navigation,the placement of top-loading percutaneous screws carries a lower risk of adjacent-FVs than does the open technique; when FVs occur,they tend to be less serious.Performing a single-level open lumbar fusion,or the fusion of the L5-S1

  10. Correction of post-traumatic kyphosis using intermediate facet joints as fulcrum in dorso-lumbar spine injuries

    Directory of Open Access Journals (Sweden)

    Agrawal Amit

    2006-01-01

    Full Text Available Background : Post traumatic kyphotic deformity are managed by different methods. Posterior stabilization of dorso-lumbar fractures with transpedicular screws and rods using intermediate facets as fulcrum can restore body height. Methods and material : In a retrospective clinical study 6 consecutive patients with complete or incomplete neurological deficits as a result of the dorso-lumbar fractures were included. Local kyphosis was measured as the angle between the upper and lower end plates of the collapsed vertebrae preoperatively, postoperatively and at the last follow-up visit. The neurological condition of the patients was recorded in the pre-op and follow up period according to Frankel grading systems. Stabilization with pedicle screw fixation and posterior fusion with autogenous bone chips were done after decompression in all 6 patients included in this study. The outcome of the study was evaluated with regard to the correction of kyphotic deformity and increase in vertebral body height after adequate neural canal decompression and fusion. Results : Of the 6 patients 4 were Frankel A and 2 Frankel C pre-operatively. Three patients sustained wedge fracture and three sustained burst fracture. The most commonly affected vertebra was L 1 with 4 cases followed by L 2 . The preoperative mean kyphotic angle was 23.3° (17°-28°, and was corrected to 15.8 (12° - 22° with a correction rate of 32.3% (21.4 - 43.5 % in the post-operative period and this correction was improved at three months follow up and the final correction was measured to be 46.3% (22.7-59.0 %. Serial postoperative radiographic follow-up assessment showed maintenance of kyphotic correction. Minimum correction of body height was .05 cm (correction rate-1.8% and maximum correction was .65 cm (correction rate-28.9% in post-operative period with a mean of 0.29 cm (correction rate-13.1%. Conclusions : Preserved the intermediate articular processes can be used as fulcrum to reduce

  11. Photo-assisted Kelvin probe force microscopy investigation of three dimensional GaN structures with various crystal facets, doping types, and wavelengths of illumination

    Science.gov (United States)

    Ali Deeb, Manal; Ledig, Johannes; Wei, Jiandong; Wang, Xue; Wehmann, Hergo-Heinrich; Waag, Andreas

    2017-08-01

    Three dimensional GaN structures with different crystal facets and doping types have been investigated employing the surface photo-voltage (SPV) method to monitor illumination-induced surface charge behavior using Kelvin probe force microscopy. Various photon energies near and below the GaN bandgap were used to modify the generation of electron-hole pairs and their motion under the influence of the electric field near the GaN surface. Fast and slow processes for Ga-polar c-planes on both Si-doped n-type as well as Mg-doped p-type GaN truncated pyramid micro-structures were found and their origin is discussed. The immediate positive (for n-type) and negative (for p-type) SPV response dominates at band-to-band and near-bandgap excitation, while only the slow process is present at sub-bandgap excitation. The SPV behavior for the semi-polar facets of the p-type GaN truncated pyramids has a similar characteristic to that on its c-plane, which indicates that it has a comparable band bending and no strong influence of the polarity-induced charges is detectable. The SPV behavior of the non-polar m-facets of the Si-doped n-type part of a transferred GaN column is similar to that of a clean c-plane GaN surface during illumination. However, the SPV is smaller in magnitude, which is attributed to intrinsic surface states of m-plane surfaces and their influence on the band bending. The SPV behavior of the non-polar m-facet of the slightly Mg-doped part of this GaN column is found to behave differently. Compared to c- and r-facets of p-type surfaces of GaN-light-emitting diode micro-structures, the m-plane is more chemically stable.

  12. Advances in neurobiological mechanism of cervical facet joint pain%颈椎小关节源性疼痛机制的神经生物学研究进展

    Institute of Scientific and Technical Information of China (English)

    唐峰

    2015-01-01

    Diseases of cervical facet joint is a common source of chronic neck pain.Clinically,the accuracy and stability of the diagnosis of cervical facet joint-induced pain is often been concerned,whereas the pathophysiology and pain mechanism,especially the related neurobiological information were still not recognized adequately.In this paper,researches in pain from cervical facet joint,which is a integrated reaction regulated and maintained by all kinds of inflammatory factors and neurotransmitters,were reviewed from the aspect of cytological level of pain induction: the innervation and the distribution of pain receptors of cervical facet joint were introduced,irreversible neuropathological changes of cervical facet joint after chronic injuries were discussed which involved neuron activation,inflammatory cytokines release and changes of neuronal phenotype,at the same time,neurotransmitters and peptides involved in starting and sustaining the facet joint pain were emphasized which including the following three categories: pain neurotransmitters,stress-related proteins and local inflammatory factors,as well as spinal glutamate.%颈椎小关节疾病是颈部慢性疼痛的常见来源,临床上较为关注其诊断的精确性和稳定性,而对病理生理及疼痛机制,特别是相关神经生物学研究缺乏足够的认识.该文从疼痛产生的细胞学水平层面对颈椎小关节源性疼痛这一由多种炎性因子及神经递质参与调节及维持的综合反应进行综述:介绍颈椎小关节神经支配及其疼痛感受器的分布情况,阐述慢性损伤后小关节发生的不可逆的神经病理变化(包括神经元激活、炎性因子释放和神经元免疫表型改变等),并重点介绍其中参与疼痛启动与维持的疼痛传入递质、应激相关蛋白和局部炎性因子、脊髓谷氨酸等三大类神经递质和肽类.

  13. Intra-Articular Knee Contact Force Estimation During Walking Using Force-Reaction Elements and Subject-Specific Joint Model.

    Science.gov (United States)

    Jung, Yihwan; Phan, Cong-Bo; Koo, Seungbum

    2016-02-01

    Joint contact forces measured with instrumented knee implants have not only revealed general patterns of joint loading but also showed individual variations that could be due to differences in anatomy and joint kinematics. Musculoskeletal human models for dynamic simulation have been utilized to understand body kinetics including joint moments, muscle tension, and knee contact forces. The objectives of this study were to develop a knee contact model which can predict knee contact forces using an inverse dynamics-based optimization solver and to investigate the effect of joint constraints on knee contact force prediction. A knee contact model was developed to include 32 reaction force elements on the surface of a tibial insert of a total knee replacement (TKR), which was embedded in a full-body musculoskeletal model. Various external measurements including motion data and external force data during walking trials of a subject with an instrumented knee implant were provided from the Sixth Grand Challenge Competition to Predict in vivo Knee Loads. Knee contact forces in the medial and lateral portions of the instrumented knee implant were also provided for the same walking trials. A knee contact model with a hinge joint and normal alignment could predict knee contact forces with root mean square errors (RMSEs) of 165 N and 288 N for the medial and lateral portions of the knee, respectively, and coefficients of determination (R2) of 0.70 and -0.63. When the degrees-of-freedom (DOF) of the knee and locations of leg markers were adjusted to account for the valgus lower-limb alignment of the subject, RMSE values improved to 144 N and 179 N, and R2 values improved to 0.77 and 0.37, respectively. The proposed knee contact model with subject-specific joint model could predict in vivo knee contact forces with reasonable accuracy. This model may contribute to the development and improvement of knee arthroplasty.

  14. Constraint Force Analysis of Metamorphic Joints Basedon the Augmented Assur Groups

    Institute of Scientific and Technical Information of China (English)

    LI Shujun; WANG Hongguang; YANG Qiang

    2015-01-01

    In order to obtain a simple way for the force analysis of metamorphic mechanisms, the systematic method to unify the force analysis approach of metamorphic mechanisms as that of conventional planar mechanisms is proposed. A force analysis method of metamorphic mechanisms is developed by transforming the augmented Assur groups into Assur groups, so that the force analysis problem of metamorphic mechanisms is converted into the force analysis problems of conventional planar mechanisms. The constraint force change rules and values of metamorphic joints are obtained by the proposed method, and the constraint force analysis equations of revolute metamorphic joints in augmented Assur group RRRR and prismatic metamorphic joints in augmented Assur group RRPR are deduced. The constraint force analysis is illustrated by the constrained spring force design of paper folding metamorphic mechanism, and its metamorphic working process is controlled by the spring force and geometric constraints of metamorphic joints. The results of spring force show that developped design method and approach are feasible and practical. By transforming augmented Assur groups into Assur groups, a new method for the constraint force analysis of metamorphic joints is proposed firstly to provide the basis for dynamic analysis of metamorphic mechanism.

  15. Evaluation of knee joint forces during kneeling work with different kneepads.

    Science.gov (United States)

    Xu, Hang; Jampala, Sree; Bloswick, Donald; Zhao, Jie; Merryweather, Andrew

    2017-01-01

    The main purpose of this study is to determine knee joint forces resulting from kneeling work with and without kneepads to quantify how different kneepads redistribute force. Eleven healthy males simulated a tile setting task to different locations during six kneepad states (five different kneepad types and without kneepad). Peak and average forces on the anatomical landmarks of both knees were obtained by custom force sensors. The results revealed that kneepad design can significantly modify the forces on the knee joint through redistribution. The Professional Gel design was preferred among the five tested kneepads which was confirmed with both force measurements and participants' responses. The extreme reaching locations induced significantly higher joint forces on left knee or right knee depending on task. The conclusion of this study is that a properly selected kneepad for specific tasks and a more neutral working posture can modify the force distribution on the knees and likely decrease the risk of knee disorders from kneeling work.

  16. Strain and load thresholds for cervical muscle recruitment in response to quasi-static tensile stretch of the caprine C5-C6 facet joint capsule.

    Science.gov (United States)

    Azar, Nadia R; Kallakuri, Srinivasu; Chen, Chaoyang; Lu, Ying; Cavanaugh, John M

    2009-12-01

    The aim of this study was to investigate the response of cervical muscles to physiologic tensile stretch of cervical facet joint capsule (FJC) at a quasi-static displacement rate of 0.5mm/s. In vivo caprine left C5-C6 FJC preparations were subjected to an incremental tensile displacement paradigm. EMG activity was recorded during FJC stretch from the right trapezius (TR) and multifidus (MF) muscle groups at the C5 and C6 levels and bilaterally from the sternomastoid (SM) and longus colli (LC) muscle groups at the C5-C6 level. Onset of muscular activity was later analyzed using visual and computer-based methods. Capsule load and strain at the time of onset were recorded and compared between the muscle groups. Results indicated capsule load was a better indicator of the tensile stretch thresholds for muscular recruitment than capsule strain. MF responded at significantly smaller capsule loads than TR and LC, while TR and LC activation loads were not significantly different. SM did not respond to physiologic FJC stretch. Muscle group recruitment order reflected the muscles' fiber type compositions and functional roles in the spine. This study provides the first evidence that the cervical ligamento-muscular reflex pathways are activated via tensile FJC stretch and extend to superficial and deep musculature on the anterior and posterior aspects of the neck, ipsilateral and contralateral to the side of FJC stretch.

  17. Bending stresses in Facetted Glass Shells

    DEFF Research Database (Denmark)

    Bagger, Anne; Jönsson, Jeppe; Almegaard, Henrik

    2008-01-01

    A shell structure of glass combines a highly effective structural principle with a material of optimal permeability to light. A facetted shell structure has a piecewise plane geometry, and together the facets form an approximation to a curved surface. A distributed load on a plane-based facetted...... structure will locally cause bending moments in the loaded facets. The bending stresses are dependent on the stiffness of the joints. Approximate solutions are developed to estimate the magnitude of the bending stresses. A FE-model of a facetted glass shell structure is used to validate the expressions...

  18. Is it possible to reduce the knee joint compression force during level walking with hiking poles?

    Science.gov (United States)

    Jensen, S B; Henriksen, M; Aaboe, J; Hansen, L; Simonsen, E B; Alkjaer, T

    2011-12-01

    Walking with hiking poles has become a popular way of exercising. Walking with poles is advocated as a physical activity that significantly reduces the loading of the hip, knee and ankle joints. We have previously observed that pole walking does not lead to a reduction of the load on the knee joint. However, it is unclear whether an increased force transmitted through the poles can reduce the load on the knee joint. Thus, the purpose of the present study was to investigate if an increased load transmitted through the arms to the poles could reduce the knee joint compression force during level walking with poles. We hypothesized that an increased pole force would result in a reduction of the knee joint compression force. Gait analyses from 10 healthy subjects walking with poles were obtained. The pole force was measured simultaneously during the gait analyses. The knee joint compression forces were estimated by using a biomechanical knee joint model. The results showed that the subjects were able to increase the pole force by 2.4 times the normal pole force. However, this did not lead to a reduction in the knee joint compressive force and we rejected our hypothesis. In conclusion, the use of poles during level walking does not seem to reduce knee joint compressive loads. However, it is possible that the use of poles in other populations (e.g. osteoarthritis patients) and in terrain would unload the knee joint. This should be investigated in the future. © 2010 John Wiley & Sons A/S.

  19. CT Manifestations of Sacroiliac Joint, Facet Joint of Lumbar and Hip Joint in Patients with Ankylosing Spodylitis%强直性脊柱炎骶髂关节、腰椎小关节及髋关节的CT表现

    Institute of Scientific and Technical Information of China (English)

    赵菁

    2012-01-01

    Objective To investigate CT features of sacroiliac joint, facet joint of lumbar and hip joint in patients with ankylosing spodylitis (AS), so as to improve the accuracy of diagnosis and differential diagnosis. Methods Between January and October 2011, CT scan was performed for 86 patients with AS, involving sacroiliac joint in 44 cases, lumbar vertebra in 28, and hip joint in 14. Their CT findings were retrospectively analyzed. Results CT findings of AS showed that the disease mainly involved iliac side of synovial section in sacroiliac joint, facet joint of lumbar and hip joint, and the main manifestations of the disease included altered joint space, coarse articular surface or cystic destruction, subchondral sclerosis and erosion. Conclusion CT manifestations of ankylosing spodylitis in sacroiliac joint, facet joint of lumbar and hip joint have some special characteristic signs, thus CT can play an important role in diagnosis and differential diagnosis of the disease.%目的 探讨强直性脊柱炎(AS)受累骶髂关节、腰椎小关节及髋关节的病变CT表现特点,以提高诊断与鉴别诊断水平.方法 2011年1月-10月对临床确诊的强直性脊柱炎患者44例骶髂关节、28例腰椎及14例髋关节行CT扫描,回顾性分析骶髂关节、腰椎小关节及髋关节的CT表现.结果 AS患者的CT表现特点为病变主要累及骶髂关节滑膜部的髂骨侧,腰椎小关节及髋关节则表现为关节间隙改变、关节面毛糙及囊状破坏、面下骨硬化或吸收等改变.结论 AS骶髂关节、腰椎小关节及髋关节的CT表现具有一定特征,CT具有重要的诊断及鉴别诊断价值.

  20. Vacuum facet phenomenon: a computed tomographic sign of degenerative spondylolisthesis

    Energy Technology Data Exchange (ETDEWEB)

    Lefkowitz, D.M.; Quencer, D.M.

    1982-08-01

    A vacuum facet phenomenon, seen on computed tomography as a lens-shaped lucency within a lumbar facet joint, was observed as a consequence of degenerative spondylolisthesis. The significance of this finding is discussed.

  1. 腰椎关节突关节骨性关节炎的病因学%The etiology of the osteoarthritis of the facet joints in the lumbar spine

    Institute of Scientific and Technical Information of China (English)

    严望军; 李家顺; 贾连顺

    2003-01-01

    @@ 腰椎关节突关节骨性关节炎(lumbar facet joint osteoarthritis,LFOA或lumbar zygapophyseal joint osteoarthritis,LZOA)是常见的腰椎退行性疾病,其基本病理特点为关节突关节软骨损害、关节边缘和软骨下骨反应性增生.Goldthwait[1]最先认为部分下腰痛可能由关节突关节病变引起.

  2. Facets: Ersatz, Resource and Tag

    Science.gov (United States)

    Frické, Martin H.

    2013-01-01

    Introduction: Faceted classification appears to be of utmost importance. Ersatz facets, resource faceting and tag faceting: The distinctions are drawn between facets and ersatz facets, and between faceted resources and faceted tags. Single tag resource faceting and multiple tag information object faceting: The basic features are explored of single…

  3. Joint force protection advanced security system (JFPASS) "the future of force protection: integrate and automate"

    Science.gov (United States)

    Lama, Carlos E.; Fagan, Joe E.

    2009-09-01

    The United States Department of Defense (DoD) defines 'force protection' as "preventive measures taken to mitigate hostile actions against DoD personnel (to include family members), resources, facilities, and critical information." Advanced technologies enable significant improvements in automating and distributing situation awareness, optimizing operator time, and improving sustainability, which enhance protection and lower costs. The JFPASS Joint Capability Technology Demonstration (JCTD) demonstrates a force protection environment that combines physical security and Chemical, Biological, Radiological, Nuclear, and Explosive (CBRNE) defense through the application of integrated command and control and data fusion. The JFPASS JCTD provides a layered approach to force protection by integrating traditional sensors used in physical security, such as video cameras, battlefield surveillance radars, unmanned and unattended ground sensors. The optimization of human participation and automation of processes is achieved by employment of unmanned ground vehicles, along with remotely operated lethal and less-than-lethal weapon systems. These capabilities are integrated via a tailorable, user-defined common operational picture display through a data fusion engine operating in the background. The combined systems automate the screening of alarms, manage the information displays, and provide assessment and response measures. The data fusion engine links disparate sensors and systems, and applies tailored logic to focus the assessment of events. It enables timely responses by providing the user with automated and semi-automated decision support tools. The JFPASS JCTD uses standard communication/data exchange protocols, which allow the system to incorporate future sensor technologies or communication networks, while maintaining the ability to communicate with legacy or existing systems.

  4. Compressive force magnitude and intervertebral joint flexion/extension angle influence shear failure force magnitude in the porcine cervical spine.

    Science.gov (United States)

    Howarth, Samuel J; Callaghan, Jack P

    2012-02-02

    Despite the findings that peak anterior shear load is highly correlated with low-back pain reporting, very little research has been conducted to determine how vertebral shear injury potential is influenced. The current study quantified the combined effects of vertebral joint compression and flexion/extension postural deviation from neutral on ultimate shear failure. Ninety-six porcine cervical specimens (48C3-C4, 48C5-C6) were tested. Each specimen was randomly assigned to one of twelve combinations of compressive force (15%, 30%, 45%, or 60% of predicted compressive failure force) and flexion/extension postural deviation (extended, neutral, or flexed). Vertebral joint shear failure was induced by applying posterior shear displacement of the caudal vertebra at a constant rate of 0.15 mm/s. Throughout shear failure tests, vertebral joint kinematics were measured using an optoelectronic camera and a series of infrared light emitting diodes while shear force was measured from load cells rigidly interfaced in series with linear actuators that applied the shear displacement. Measurements of shear stiffness, ultimate force, displacement, and energy stored were made from the force-displacement data. Compressive force and postural deviation demonstrated main effects without a statistically significant interaction for any of the measurements. Shear failure force increased by 11.1% for each 15% increment in compressive force (pflexion (pflexion/extension postural deviation should be equally considered while assessing shear injury potential.

  5. Joint Force Quarterly. Issue 51, 4th Quarter, October 2008

    Science.gov (United States)

    2008-10-01

    intelligence information—we have a program under way to create a national biosurveillance integration center, which is now up and running and will...www.ieee. org/ portal /cms_docs_iportals/iportals/aboutus/ history_center/oral_history/pdfs/Parkinson379.pdf>. 13 Ibid. 14 Ibid. 15 Ibid., 6. 16...page from the Joint Electronic Library to the JDEIS portal . As the exclusive source for joint doctrine, it is imperative to raise JDEIS awareness

  6. History of the Standing Joint Force Headquarters for Elimination (SJFHQ-E): No More Ad Hoc

    Science.gov (United States)

    2014-05-22

    for a Standing Joint Force Headquarters (SJFHQ) - Core Element (CE). Washington, DC: Joint Chiefs of Staff, 2008. Creswell , John W. Qualitative...reduce the threat to the United States and its allies from nuclear, biological, chemical (NBC) weapons … as well as provide research and development...that were known and available for this research project. Project 31 Due to lack of official

  7. Glenohumeral joint reaction forces increase with critical shoulder angles representative of osteoarthritis-A biomechanical analysis.

    Science.gov (United States)

    Viehöfer, Arnd F; Snedeker, Jess G; Baumgartner, Daniel; Gerber, Christian

    2016-06-01

    Osteoarthritis (OA) of the glenohumeral joint constitutes the most frequent indication for nontraumatic shoulder joint replacement. Recently, a small critical shoulder angle (CSA) was found to be associated with a high prevalence of OA. This study aims to verify the hypothesis that a small CSA leads to higher glenohumeral joint reaction forces during activities of daily living than a normal CSA. A shoulder simulator with simulated deltoid (DLT), supraspinatus (SSP), infraspinatus/teres minor (ISP/TM), and subscapularis (SSC) musculotendinous units was constructed. The DLT wrapping on the humerus was simulated using a pulley that could be horizontally adjusted to simulate the 28° CSA found in OA or the 33° CSA found in disease-free shoulders. Over a range of motion between 6° and 82° of thoracohumeral abduction joint forces were measured using a six-axis load cell. An OA-associated CSA yielded higher net joint reaction forces than a normal CSA over the entire range of motion. The maximum difference of 26.4 N (8.5%) was found at 55° of thoracohumeral abduction. Our model thus suggests that a CSA typical for OA predisposes the glenohumeral joint to higher joint reaction forces and could plausibly play a role in joint overloading and development of OA. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1047-1052, 2016.

  8. Adaptation of multi-joint balance coordination to whole body force fields

    OpenAIRE

    Engelhart, Denise; Schouten, Alfred; Aarts, Ronald; Pasma, J.; Meskers, Carel; Maier, Andrea; Kooij, van der, Marieke

    2014-01-01

    Background and aim: The ankles and the hips play an important role in standing balance. Multi-joint coordination adapts with task, the magnitude and type of disturbance [1]. Arm studies show that postural responses are highly dependent on externally applied force fields [2]. Our aim is to study how multi-joint postural responses in standing depend on such force fields, using closed loop system identification techniques (CLSIT) where two disturbances are applied [3]. This offers knowledge abou...

  9. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces

    Science.gov (United States)

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F.; Fregly, Benjamin J.; Delp, Scott L.; Banks, Scott A.; Pandy, Marcus G.; D’Lima, Darryl D.; Lloyd, David G.

    2013-01-01

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model. PMID:24074941

  10. Subject-specific knee joint geometry improves predictions of medial tibiofemoral contact forces.

    Science.gov (United States)

    Gerus, Pauline; Sartori, Massimo; Besier, Thor F; Fregly, Benjamin J; Delp, Scott L; Banks, Scott A; Pandy, Marcus G; D'Lima, Darryl D; Lloyd, David G

    2013-11-15

    Estimating tibiofemoral joint contact forces is important for understanding the initiation and progression of knee osteoarthritis. However, tibiofemoral contact force predictions are influenced by many factors including muscle forces and anatomical representations of the knee joint. This study aimed to investigate the influence of subject-specific geometry and knee joint kinematics on the prediction of tibiofemoral contact forces using a calibrated EMG-driven neuromusculoskeletal model of the knee. One participant fitted with an instrumented total knee replacement walked at a self-selected speed while medial and lateral tibiofemoral contact forces, ground reaction forces, whole-body kinematics, and lower-limb muscle activity were simultaneously measured. The combination of generic and subject-specific knee joint geometry and kinematics resulted in four different OpenSim models used to estimate muscle-tendon lengths and moment arms. The subject-specific geometric model was created from CT scans and the subject-specific knee joint kinematics representing the translation of the tibia relative to the femur was obtained from fluoroscopy. The EMG-driven model was calibrated using one walking trial, but with three different cost functions that tracked the knee flexion/extension moments with and without constraint over the estimated joint contact forces. The calibrated models then predicted the medial and lateral tibiofemoral contact forces for five other different walking trials. The use of subject-specific models with minimization of the peak tibiofemoral contact forces improved the accuracy of medial contact forces by 47% and lateral contact forces by 7%, respectively compared with the use of generic musculoskeletal model.

  11. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement.

    Directory of Open Access Journals (Sweden)

    Robert Rasnick

    Full Text Available Total knee replacement (TKR is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (p<0.05. No differences were observed for peak joint compressive forces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups.

  12. Facet analysis

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2013-01-01

    Research Group, but it is mostly based on principles of logical division developed more than two millennia ago. Colon Classification (CC) and Bliss 2 (BC2) are among the most important systems developed on this theoretical basis, but it has also influenced the development of other systems......The facet-analytic paradigm is probably the most distinct approach to knowledge organization within Library and Information Science, and in many ways it has dominated what has be termed “modern classification theory”. It was mainly developed by S.R. Ranganathan and the British Classification......, such as the Dewey Decimal Classification (DDC) and is also applied in many websites. It still has a strong position in the field and it is the most explicit and “pure” theoretical approach to knowledge organization (KO) (but it is not by implication necessarily also the most important one). The strength...

  13. Effect of object width on muscle and joint forces during thumb-index finger grasping.

    Science.gov (United States)

    Vigouroux, Laurent; Domalain, Mathieu; Berton, Eric

    2011-08-01

    The objective of this study was to identify the impact of modifying the object width on muscle and joint forces while gripping objects. The experimental protocol consisted to maintain horizontally five objects of different widths (3.5, 4.5, 5.5, 6.5, and 7.5 cm) with a thumb-index finger grip. Subjects were required to grasp spontaneously the object without any instruction regarding the grip force (GF) to apply. A biomechanical model of thumb-index finger pinch was developed to estimate muscle and joint forces. This model included electromyography, fingertip force, and kinematics data as inputs. The finger joint postures and the GF varied across the object widths. The estimated muscle forces also varied significantly according to the object width. Interestingly, we observed that the muscle force/GF ratios of major flexor muscles remain particularly stable with respect to the width whereas other muscle ratios differed largely. This may argue for a control strategy in which the actions of flexors were preserved in spite of change in joint postures. The estimated joint forces tended to increase with object width and increased in the distal-proximal sense. Overall, these results are of importance for the ergonomic design of handheld objects and for clinical applications.

  14. General Roy S. Geiger, USMC: Marine Aviator, Joint Force Commander

    Science.gov (United States)

    2007-06-01

    under the wings of their planes. Brigadier General Roy Geiger, with seemingly iron nerves and tireless muscles, forced them back into their planes...that justified a separate service, independent of the Army. The Army, meanwhile, was determined to preserve its force structure in the frenzy of

  15. Plastic mechanism analysis of T-joints in RHS under concentrated force

    Science.gov (United States)

    Zhao, Xiao-Ling; Hancock, Gregory J.

    1991-11-01

    A new plastic mechanism is developed for T-joints in rectangular hollow sections (RHS) under concentrated loads. This model includes the plastic hinges in the web, the membrane force in the flange and the strain hardening of the material. It can predict the yield load, the post-yield response, and the ultimate load of a T-joint under concentrated force. The model developed is compared with the CIDECT model, the Kato model, and the modified Kato model. The yield load, the post-yield response, and the ultimate load determined from the present model are compared with 6 T-joint tests performed by Zhao and Hancock (1991) and 20 T-joint tests performed by Kato and Nishiyama (1979). The ratio (beta) of the T-joints tested varied from 0.291 to 0.890.

  16. Knee joint angle affects EMG-force relationship in the vastus intermedius muscle.

    Science.gov (United States)

    Saito, Akira; Akima, Hiroshi

    2013-12-01

    It is not understood how the knee joint angle affects the relationship between electromyography (EMG) and force of four individual quadriceps femoris (QF) muscles. The purpose of this study was to examine the effect of the knee joint angle on the EMG-force relationship of the four individual QF muscles, particularly the vastus intermedius (VI), during isometric knee extensions. Eleven healthy men performed 20-100% of maximal voluntary contraction (MVC) at knee joint angles of 90°, 120° and 150°. Surface EMG of the four QF synergists was recorded and normalized by the root mean square during MVC. The normalized EMG of the four QF synergists at a knee joint angle of 150° was significantly lower than that at 90° and 120° (P knee joint angle of 150°. Furthermore, the neuromuscular activation of the VI was the most sensitive to change in muscle length among the four QF synergistic muscles.

  17. Joint Force Quarterly. Issue 38, 3rd Quarter, July 2005

    Science.gov (United States)

    2005-07-01

    anthropologists such as Gregory Bateson served the war effort directly, first conduct- ing intelligence opera- tions in Burma for the Office of...leaders such as General James L. Jones, Jr., USMC, Supreme Allied Commander, Europe, and Admi- ral Gregory G. Johnson, USN, combatant com- mander, Joint

  18. BITE-FORCE ENDURANCE IN PATIENTS WITH TEMPOROMANDIBULAR-JOINT OSTEOARTHROSIS AND INTERNAL DERANGEMENT

    NARCIS (Netherlands)

    STEGENGA, B; BROEKHUIJSEN, ML; DEBONT, LGM; VANWILLIGEN, JD

    1992-01-01

    The aim of this study was to investigate the potential clinical relevance of testing bite force endurance in patients with articular temporomandibular disorders. The endurance of a 50 N bite force was measured in 51 patients with painful temporomandibular joint disorders. The results were compared t

  19. Three-dimensional knee joint contact forces during walking in unilateral transtibial amputees.

    Science.gov (United States)

    Silverman, Anne K; Neptune, Richard R

    2014-08-22

    Individuals with unilateral transtibial amputations have greater prevalence of osteoarthritis in the intact knee joint relative to the residual leg and non-amputees, but the cause of this greater prevalence is unclear. The purpose of this study was to compare knee joint contact forces and the muscles contributing to these forces between amputees and non-amputees during walking using forward dynamics simulations. We predicted that the intact knee contact forces would be higher than those of the residual leg and non-amputees. In the axial and mediolateral directions, the intact and non-amputee legs had greater peak tibio-femoral contact forces and impulses relative to the residual leg. The peak axial contact force was greater in the intact leg relative to the non-amputee leg, but the stance phase impulse was greater in the non-amputee leg. The vasti and hamstrings muscles in early stance and gastrocnemius in late stance were the largest contributors to the joint contact forces in the non-amputee and intact legs. Through dynamic coupling, the soleus and gluteus medius also had large contributions, even though they do not span the knee joint. In the residual leg, the prosthesis had large contributions to the joint forces, similar to the soleus in the intact and non-amputee legs. These results identify the muscles that contribute to knee joint contact forces during transtibial amputee walking and suggest that the peak knee contact forces may be more important than the knee contact impulses in explaining the high prevalence of intact leg osteoarthritis.

  20. A 3D mathematical model to predict spinal joint and hip joint force for trans-tibial amputees with different SACH foot pylon adjustments.

    Science.gov (United States)

    Yu, Chung-huang; Hung, Yu-Cheng; Lin, Yang-Hua; Chen, Guan-Xun; Wei, Shun-Hwa; Huang, Chang-Hung; Chen, Chen-Sheng

    2014-09-01

    A solid-ankle cushioned heel (SACH) foot is a non-joint foot without natural ankle function. Trans-tibial amputees may occur toe scuffing in the late swing phase due to a lack of active dorsiflexion. To address this problem, clinical guidelines suggests shortening the pylon to produce a smooth gait. However, this causes a leg length discrepancy, induces asymmetry in the hip joint, and causes an overload of L5/S1 joint force. Therefore, this study aimed to investigate the influence of different prosthesis pylons on the hip joint and L5/S1 joint forces. Ten subjects were recruited using leg length for normalisation. Four different pylon reductions (0%, 1%, 2%, and 3%) were used for gait analysis. A Vicon system and force plates were used to collect kinematic data and ground reaction force, respectively. The software package MATLAB was used to create a mathematical model for evaluating the symmetry and force of the hip joint and the low back force of the L5/S1 joint. The model was validated by the correlation coefficient (CC=0.947) and root mean square (RMS=0.028 BW). The model estimated that the 1% group had a symmetrical hip joint force and a lower L5/S1 joint force in the vertical direction. This study indicates that a 1% pylon shortening on a SACH prosthesis is appropriate for a trans-tibial amputee.

  1. Evaluation of predicted knee-joint muscle forces during gait using an instrumented knee implant.

    Science.gov (United States)

    Kim, Hyung J; Fernandez, Justin W; Akbarshahi, Massoud; Walter, Jonathan P; Fregly, Benjamin J; Pandy, Marcus G

    2009-10-01

    Musculoskeletal modeling and optimization theory are often used to determine muscle forces in vivo. However, convincing quantitative evaluation of these predictions has been limited to date. The present study evaluated model predictions of knee muscle forces during walking using in vivo measurements of joint contact loading acquired from an instrumented implant. Joint motion, ground reaction force, and tibial contact force data were recorded simultaneously from a single subject walking at slow, normal, and fast speeds. The body was modeled as an 8-segment, 21-degree-of-freedom articulated linkage, actuated by 58 muscles. Joint moments obtained from inverse dynamics were decomposed into leg-muscle forces by solving an optimization problem that minimized the sum of the squares of the muscle activations. The predicted knee muscle forces were input into a 3D knee implant contact model to calculate tibial contact forces. Calculated and measured tibial contact forces were in good agreement for all three walking speeds. The average RMS errors for the medial, lateral, and total contact forces over the entire gait cycle and across all trials were 140 +/- 40 N, 115 +/- 32 N, and 183 +/- 45 N, respectively. Muscle coordination predicted by the model was also consistent with EMG measurements reported for normal walking. The combined experimental and modeling approach used in this study provides a quantitative framework for evaluating model predictions of muscle forces in human movement.

  2. Joint Force Quarterly. Issue 66, 3rd Quarter 2012

    Science.gov (United States)

    2012-07-01

    security patrol in Sangin, Afghanistan (British Royal Army/James Elmer); Navy SEALs hoisted onto Air Force Special Operations CV-22 Osprey at Hurlburt...acknowledged by all to have been a self- inflicted source of friction that demanded immediate corrective attention. As another outgrowth of the IDF’s...earlier cooperative training with IDF ground forces that familiarized them before- hand with virtually any friction point that might arise. After it was

  3. Strategic Joint Staff Force Posture and Readiness Process Analysis

    Science.gov (United States)

    2014-03-31

    this project. Other DND information systems that could provide data to FP&R are Defence Resource Management Information System (DRMIS-SAP), the Human ... Resources Management System ( HRMS -PeopleSoft), the Regular and Reserve Force pay systems, and others. 14.3. FP&R Collection Tool Data Structure...cause-effect relationships can be more readily identified, thus enabling the CDS to direct and manage resources assigned to the operational force for

  4. Enhanced Army Airborne Forces: A New Joint Operational Capability

    Science.gov (United States)

    2014-01-01

    WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) RAND Corporation,Arroyo Center,1776 Main Street , P.O. Box 2138,Santa Monica,CA...including Venezuela , Syria, and North Korea, among others) that either have the S-300 (SA-10) SAM or are planning to acquire the system.6 4 Bruce R...or by remote control by irregular forces. Often, irregular forces will use weapons of this type to harass airfields. Similar weapons were used as

  5. Joint Force Quarterly (Issue 71, 4th Quarter, October 2013)

    Science.gov (United States)

    2013-01-01

    of this scale occurs only through willing teamwork and cooperation among joint commanders who have the mandate to train and maintain an airborne...Effort in Libya,” The Washington Post, June 3, 2011, A7. 41 Ibid. 42 President Gerald Ford submitted 4 reports; President Jimmy Carter 1; President...advance. Here is friction. 21 Ibid. 22 Sir Basil Henry Liddell Hart, Strategy (New York: Praeger, 1954), 207. 23 Keegan, 403–404. 24 Ibid., 404. 25

  6. The Business of Bundling: Joining Forces on Joint Replacement.

    Science.gov (United States)

    Kaldy, Joanne

    2016-03-01

    A mandated bundled-payment program for joint replacement is in place in several regions across the country, and practitioners such as pharmacists are still sorting out their roles in this federal initiative. To get involved, pharmacists need to establish connections with area hospitals and physician groups to promote and document their ability to manage medications, reduce and eliminate medication-related problems and rehospitalizations, and work with patients to maximize adherence and improve communication for those undergoing hip and knee replacement.

  7. COUNTER-UAV SOLUTIONS FOR THE JOINT FORCE

    Science.gov (United States)

    2017-04-06

    College, Air University, Maxwell AFB, AL. Commander Praisler graduated in 1997 from the United States Merchant Marine Academy in Kings Point, NY...Department of Defense, Capstone Concept for Joint Operations V3.0, (January 2009), iv. 35 Stephen L. Kwast, Leiutenant General (USAF), “Innovation...Kwast, Stephen L., “Innovation through DoD Collaboration with Civilian Academia and Business.” Keynote Speech. Futures Lab, Auburn Montgomery Campus. January 20, 2017.

  8. Accuracy and repeatability of a new method for measuring facet loads in the lumbar spine.

    Science.gov (United States)

    Wilson, Derek C; Niosi, Christina A; Zhu, Qingan A; Oxland, Thomas R; Wilson, David R

    2006-01-01

    We assessed the repeatability and accuracy of a relatively new, resistance-based sensor (Tekscan 6900) for measuring lumbar spine facet loads, pressures, and contact areas in cadaver specimens. Repeatability of measurements in the natural facet joint was determined for five trials of four specimens loaded in pure moment (+/- 7.5 N m) flexibility tests in axial rotation and flexion-extension. Accuracy of load measurements in four joints was assessed by applying known compressive loads of 25, 50, and 100 N to the natural facet joint in a materials testing machine and comparing the known applied load to the measured load. Measurements of load were obtained using two different calibration approaches: linear and two-point calibrations. Repeatability for force, pressure, and area (average of standard deviation as a percentage of the mean for all trials over all specimens) was 4-6% for axial rotation and 7-10% for extension. Peak resultant force in axial rotation was 30% smaller when calculated using the linear calibration method. The Tekscan sensor overestimated the applied force by 18 +/- 9% (mean+/-standard deviation), 35 +/- 7% and 50 +/- 9% for compressive loads of 100, 50, and 25 N, respectively. The two-point method overestimated the loads by 35 +/- 16%, 45 +/- 7%, and 56 +/- 10% for the same three loads. Our results show that the Tekscan sensor is repeatable. However, the sensor measurement range is not optimal for the small loads transmitted by the facets and measurement accuracy is highly dependent on calibration protocol.

  9. FacetGist: Collective Extraction of Document Facets in Large Technical Corpora

    Science.gov (United States)

    Siddiqui, Tarique; Ren, Xiang; Parameswaran, Aditya; Han, Jiawei

    2017-01-01

    Given the large volume of technical documents available, it is crucial to automatically organize and categorize these documents to be able to understand and extract value from them. Towards this end, we introduce a new research problem called Facet Extraction. Given a collection of technical documents, the goal of Facet Extraction is to automatically label each document with a set of concepts for the key facets (e.g., application, technique, evaluation metrics, and dataset) that people may be interested in. Facet Extraction has numerous applications, including document summarization, literature search, patent search and business intelligence. The major challenge in performing Facet Extraction arises from multiple sources: concept extraction, concept to facet matching, and facet disambiguation. To tackle these challenges, we develop FacetGist, a framework for facet extraction. Facet Extraction involves constructing a graph-based heterogeneous network to capture information available across multiple local sentence-level features, as well as global context features. We then formulate a joint optimization problem, and propose an efficient algorithm for graph-based label propagation to estimate the facet of each concept mention. Experimental results on technical corpora from two domains demonstrate that Facet Extraction can lead to an improvement of over 25% in both precision and recall over competing schemes.

  10. Evidence of residual force enhancement for multi-joint leg extension.

    Science.gov (United States)

    Hahn, Daniel; Seiberl, Wolfgang; Schmidt, Susanne; Schweizer, Katrin; Schwirtz, Ansgar

    2010-05-28

    Force enhancement is a well accepted property of skeletal muscle and has been observed at all structural levels ranging from single myofibrils to voluntarily activated m. quadriceps femoris in vivo. However, force enhancement has not been studied for multi-joint movements like human leg extension; therefore knowledge about its relevance in daily living remains limited. The purpose of this study was to determine whether there is force enhancement during maximal voluntary multi-joint leg extension. Human leg extension was studied (n=22) on a motor driven leg press dynamometer where external reaction forces under the feet as well as activity of 8 lower extremity muscles were measured. In addition, torque in the ankle and knee joints was calculated using inverse dynamics. The steady-state isometric force, joint torques, and muscle activation after active stretch (20 degrees stretch amplitude at 60 degrees/s) were compared with the corresponding values obtained during isometric reference contractions. There was consistent force enhancement during and following stretch for both forces and joint torques. Potentiation during stretch reached values between 26% and 30%, while a significant force enhancement of 10.5-12.3% and 4.3-7.4% remained 0.5-1 and 2.5-3s after stretch, respectively. During stretch, EMG signals of m. gastrocnemius medialis and lateralis were significantly increased, while following stretch all analyzed muscles showed the same activity as during the reference contractions. We conclude from these results that force enhancement exists in everyday movements and should be accounted for when analyzing or modelling human movement.

  11. Predicting sagittal plane biomechanics that minimize the axial knee joint contact force during walking.

    Science.gov (United States)

    Miller, Ross H; Brandon, Scott C E; Deluzio, Kevin J

    2013-01-01

    Both development and progression of knee osteoarthritis have been associated with the loading of the knee joint during walking. We are, therefore, interested in developing strategies for changing walking biomechanics to offload the knee joint without resorting to surgery. In this study, simulations of human walking were performed using a 2D bipedal forward dynamics model. A simulation generated by minimizing the metabolic cost of transport (CoT) resembled data measured from normal human walking. Three simulations targeted at minimizing the peak axial knee joint contact force instead of the CoT reduced the peak force by 12-25% and increased the CoT by 11-14%. The strategies used by the simulations were (1) reduction in gastrocnemius muscle force, (2) avoidance of knee flexion during stance, and (3) reduced stride length. Reduced gastrocnemius force resulted from a combination of changes in activation and changes in the gastrocnemius contractile component kinematics. The simulations that reduced the peak contact force avoided flexing the knee during stance when knee motion was unrestricted and adopted a shorter stride length when the simulated knee motion was penalized if it deviated from the measured human knee motion. A higher metabolic cost in an offloading gait would be detrimental for covering a long distance without fatigue but beneficial for exercise and weight loss. The predicted changes in the peak axial knee joint contact force from the simulations were consistent with estimates of the joint contact force in a human subject who emulated the predicted kinematics. The results demonstrate the potential of using muscle-actuated forward dynamics simulations to predict novel joint offloading interventions.

  12. 脊柱小关节紊乱影像学诊断与整脊疗法效果分析%Analysis of imaging diagnosis of spinal facet joint disorder and effect of spinal rotation massage

    Institute of Scientific and Technical Information of China (English)

    余任辉; 林家伟; 王晓国

    2013-01-01

    Objective To investigate the pathogenetic rmechanism of the spinal facet joint disorder and improve the accuracy of imaging diagnosis to reduce the possibility of spinal degenerative osteoarthropathy(DO).Methods The spinal X-ray plain film,CT and MRI images of 300 cases from 15 to 45 years old with muscle soreness in neck,chest and back caused by spinal small joint disorder were retrospectively analyzed.Results The results showed that this disease was mainly caused by improper posture,long-term spinal joint chronic strain,scoliosis by spinal or small joint developmental malformation and joint change resulted by spinal joint asymmetry,which had clinical manifestation shown by the imaging like typical spinal joint asymmetry,pen type hyperostosis oseosclerosis for articular surface and nonspecific inflammation of its surrounding soft tissue.Moreover,the facet joint will be deteriorated with the age of the patients.Conclusions The imaging could be used for spinal facet joint disorder diagnosis (definite diagnosis and differential diagnosis),and X-ray examination is still a very important method.Meanwhile,CT and MRI images can show us the change of spinal facet joint and the surrounding soft tissue more clearly and identify the change of the herniated disk as well as the diseases caused by other reasons.And the spinal rotation massage method has good effects.%目的 探索脊柱小关节紊乱的发生机制,提高脊柱小关节紊乱影像学诊断的准确性,减慢脊柱退行性骨关节病的发生.方法 回顾性分析300例15~45岁年龄组脊柱小关节紊乱引起颈、胸、腰背部酸痛患者的脊椎X线平片或CT平扫或MRI资料.结果 脊柱小关节紊乱主要是姿势不当、长期慢性劳损或脊柱或小关节发育畸形致脊柱侧弯畸形或先天椎小关节不对称造成小关节病变所致,有其典型椎小关节不对称、关节面笔样增生硬化及周围软组织非特异炎性改变等影像学表现,随着年龄增长

  13. Knee Joint Loads and Surrounding Muscle Forces during Stair Ascent in Patients with Total Knee Replacement.

    Science.gov (United States)

    Rasnick, Robert; Standifird, Tyler; Reinbolt, Jeffrey A; Cates, Harold E; Zhang, Songning

    2016-01-01

    Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (pforces between groups. Some muscle force compensatory strategies appear to be present in both the loading and push-off phases. Evidence from knee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups.

  14. Value-Driven Enterprise Architecture Evaluation for the Joint Force Protection Advanced Security System

    Science.gov (United States)

    2009-03-25

    observed and reported – Lowest level of technology readiness TRL 2 Technology concept and/or application formulated invention begins TRL 3...in Figure 4.8. If the weight is set to any value between zero and one, a new ranking can be found by observing the order of alternatives. Locally...Joint Task List. Washington: Joint Staff. Jurk, D. M. (2002). Decision Analysis with Value-Focused Thinking as a Methology to Select Force Protection

  15. A Study of Joint Transformation at United States Joint Forces Command

    Science.gov (United States)

    2007-11-02

    College, 1989), 19. 24Allen Frenzel , COL, USA, Restructuring the Armed Forces to Meet U.S. National Security Interests Through 2015, AWC Strategic Research...1984. Frenzel , Allen, COL, USA. Restructuring the Armed Forces to Meet U.S. National Security Interests Through 2015, AWC Strategic Research Paper

  16. The biomechanical effects of variation in the maximum forces exerted by trunk muscles on the joint forces and moments in the lumbar spine: a finite element analysis.

    Science.gov (United States)

    Kim, K; Lee, S K; Kim, Y H

    2010-10-01

    The weakening of trunk muscles is known to be related to a reduction of the stabilization function provided by the muscles to the lumbar spine; therefore, strengthening deep muscles might reduce the possibility of injury and pain in the lumbar spine. In this study, the effect of variation in maximum forces of trunk muscles on the joint forces and moments in the lumbar spine was investigated. Accordingly, a three-dimensional finite element model of the lumbar spine that included the trunk muscles was used in this study. The variation in maximum forces of specific muscle groups was then modelled, and joint compressive and shear forces, as well as resultant joint moments, which were presumed to be related to spinal stabilization from a mechanical viewpoint, were analysed. The increase in resultant joint moments occurred owing to decrease in maximum forces of the multifidus, interspinales, intertransversarii, rotatores, iliocostalis, longissimus, psoas, and quadratus lumborum. In addition, joint shear forces and resultant joint moments were reduced as the maximum forces of deep muscles were increased. These results from finite element analysis indicate that the variation in maximum forces exerted by trunk muscles could affect the joint forces and joint moments in the lumbar spine.

  17. Joint Force Quarterly. Issue 60, 1st Quarter 2011

    Science.gov (United States)

    2011-01-01

    percent by 2015, and sail the Great Green Fleet by 2016. The Air Force is focusing on the three goals of reducing demand, increasing supply through...life. Counterinsurgency is therefore about breaking alternative norma - tive systems (for example, the system of justice provided by the Taliban in...space, and it embraces all systems that incorporate software as a key element. It is a medium, moreover, in which informa- tion can be created and

  18. Joint Force Quarterly. Issue 48, 1st Quarter 2008

    Science.gov (United States)

    2008-01-01

    American War) under Presi- dent William McKinley; and, most recently, post–Pearl Harbor in the Hawaiian Islands under President Franklin Roosevelt...strategic context remain wedded to legacy ideas developed decades ago. Innovative thought must bridge the ongoing changes within the separate...determine resource commitments, and it remains to be seen if the U.S. Air Force will invest in an air advisory ounce of prevention or remain wedded to

  19. Personnel Security during Joint Operations with Foreign Military Forces

    Science.gov (United States)

    2013-08-01

    century society into the twenty-first century encounters a number of obstacles. Illiteracy and innumeracy rates are high, and repressive social values are...Operations with Foreign Military Forces Feature quickly degraded into executions for social infractions like blasphemy. Repression soon followed, and the...the Soviets inherited. Objective: Why Do They Hate Us? This article addresses the primary issue of the dramatic increase in the number of insider

  20. Influence of Muscle-Tendon Wrapping on Calculations of Joint Reaction Forces in the Equine Distal Forelimb

    Directory of Open Access Journals (Sweden)

    Jonathan S. Merritt

    2008-01-01

    Full Text Available The equine distal forelimb is a common location of injuries related to mechanical overload. In this study, a two-dimensional model of the musculoskeletal system of the region was developed and applied to kinematic and kinetic data from walking and trotting horses. The forces in major tendons and joint reaction forces were calculated. The components of the joint reaction forces caused by wrapping of tendons around sesamoid bones were found to be of similar magnitude to the reaction forces between the long bones at each joint. This finding highlighted the importance of taking into account muscle-tendon wrapping when evaluating joint loading in the equine distal forelimb.

  1. A feasibility study for experimentally determining dynamic force distribution in a lap joint

    Energy Technology Data Exchange (ETDEWEB)

    Mayes, Randall Lee [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2013-11-01

    Developing constitutive models of the physics in mechanical joints is currently stymied by inability to measure forces and displacements within the joint. The current state of the art estimates whole joint stiffness and energy loss per cycle from external measured force input and one or two acceleration responses. To validate constitutive models beyond this state requires a measurement of the distributed forces and displacements at the joint interface. Unfortunately, introducing measurement devices at the interface completely disrupts the desired physics. A feasibility study is presented for a non-intrusive method of solving for the interface dynamic forces from an inverse problem using full field measured responses. The responses come from the viewable surface of a beam. The noise levels associated with digital image correlation and continuous scanning laser Doppler velocimetry are evaluated from typical beam experiments. Two inverse problems are simulated. One utilizes the extended Sum of Weighted Accelerations Technique (SWAT). The second is a new approach dubbed the method of truncated orthogonal forces. These methods are much more robust if the contact patch geometry is well identified. Various approaches to identifying the contact patch are investigated, including ion marker tracking, Prussian blue and ultrasonic measurements. A typical experiment is conceived for a beam which has a lap joint at one end with a single bolt connecting it to another identical beam. In a virtual test using the beam finite element analysis, it appears that the SWAT inverse method requires evaluation of too many coefficients to adequately identify the force distribution to be viable. However, the method of truncated orthogonal forces appears viable with current digital image correlation (and probably other) imaging techniques.

  2. Flange joint system for SRF cavities utilizing high force spring clamps for low particle generation

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-05

    A flange joint system for SRF cavities. The flange joint system includes a set of high force spring clamps that produce high force on the simple flanges of Superconducting Radio Frequency (SRF) cavities to squeeze conventional metallic seals. The system establishes the required vacuum and RF-tight seal with minimum particle contamination to the inside of the cavity assembly. The spring clamps are designed to stay within their elastic range while being forced open enough to mount over the flange pair. Upon release, the clamps have enough force to plastically deform metallic seal surfaces and continue to a new equilibrium sprung dimension where the flanges remain held against one another with enough preload such that normal handling will not break the seal.

  3. A modeling approach to compute modification of net joint forces caused by coping movements in obstetric brachial plexus palsy

    Science.gov (United States)

    2013-01-01

    Background Many disorders of the musculoskeletal system are caused by modified net joint forces resulting from individual coping movement strategies of patients suffering from neuromuscular diseases. Purpose of this work is to introduce a personalized biomechanical model which allows the calculation of individual net joint forces via inverse dynamics based on anthropometry and kinematics of the upper extremity measured by 3D optoelectronical motion analysis. Methods The determined resulting net joint forces in the anatomical axis of movement may be used to explain the reason for possible malfunction of the musculoskeletal system, especially joint malformation. For example the resulting net joint forces in the humerothoracic joint from simulations are compared to a sample of children presenting obstetric brachial plexus palsy showing an internal shoulder rotation position and a sample of healthy children. Results The results presented from the simulation show that an increased internal shoulder rotation position leads to increased net joint forces in the humerothoracic joint. A similar behavior is presented for the subjects suffering from brachial plexus palsy with an internal shoulder rotation position. Conclusions The increased net joint forces are a possible reason for joint malformation in the humerothoracic joint caused by coping movements resulting from neuromuscular dysfunction as stated in literature. PMID:24139445

  4. The Future of Indigenous Security Force Training: Considerations for the Joint Operational Commander

    Science.gov (United States)

    2007-11-06

    in Iraq and Afghanistan may not be sustained as these conflicts wind down. Where the U.S. conducts regime change or in failed states, U.S. forces...requirements of the Joint Force as across the full range of military operations ( ROMO ). 29 A major part of the Army transformation adds high demand... ROMO . Specific enhancements in planning, communications, computers, intelligence, civil affairs, public affairs, fires and effects, air space

  5. BILATERAL GROUND REACTION FORCES AND JOINT MOMENTS FOR LATERAL SIDESTEPPING AND CROSSOVER STEPPING TASKS

    Directory of Open Access Journals (Sweden)

    William I. Sellers

    2009-03-01

    Full Text Available Racquet sports have high levels of joint injuries suggesting the joint loads during play may be excessive. Sports such as badminton employ lateral sidestepping (SS and crossover stepping (XS movements which so far have not been described in terms of biomechanics. This study examined bilateral ground reaction forces and three dimensional joint kinetics for both these gaits in order to determine the demands of the movements on the leading and trailing limb and predict the contribution of these movements to the occurrence of overuse injury of the lower limbs. A force platform and motion-analysis system were used to record ground reaction forces and track marker trajectories of 9 experienced male badminton players performing lateral SS, XS and forward running tasks at a controlled speed of 3 m·s-1 using their normal technique. Ground reaction force and kinetic data for the hip, knee and ankle were analyzed, averaged across the group and the biomechanical variables compared. In all cases the ground reaction forces and joint moments were less than those experienced during moderate running suggesting that in normal play SS and XS gaits do not lead to high forces that could contribute to increased injury risk. Ground reaction forces during SS and XS do not appear to contribute to the development of overuse injury. The distinct roles of the leading and trailing limb, acting as a generator of vertical force and shock absorber respectively, during the SS and XS may however contribute to the development of muscular imbalances which may ultimately contribute to the development of overuse injury. However it is still possible that faulty use of these gaits might lead to high loads and this should be the subject of future work

  6. Biomechanical analysis of reducing sacroiliac joint shear load by optimization of pelvic muscle and ligament forces

    NARCIS (Netherlands)

    J.J.M. Pel (Johan); C.W. Spoor (Cornelis); A.L. Pool-Goudzwaard (Annelies); G.A. Hoek van Dijke; C.J. Snijders (Chris)

    2008-01-01

    textabstractEffective stabilization of the sacroiliac joints (SIJ) is essential, since spinal loading is transferred via the SIJ to the coxal bones, and further to the legs. We performed a biomechanical analysis of SIJ stability in terms of reduced SIJ shear force in standing posture using a validat

  7. Summary of the 19th Joint EU-US Transport Task Force Workshop

    DEFF Research Database (Denmark)

    Angioni, C.; Mantica, P.; Naulin, Volker

    2015-01-01

    This conference report summarizes the contributions to, and discussions at, the 19th Joint EU-US Transport Task Force workshop, held in Culham, UK, during 8-11 September 2014. The workshop was organized under six topics: momentum transport, energetic particles, challenges in modelling transport i...

  8. Forces on bends and T-joints due to multiphase flow

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Cargnelutti, M.F.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    To be able to assess the mechanical integrity of piping structures for loading to multiphase flow conditions, air-water experiments were carried out in a horizontal 1" pipe system. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating co

  9. Forces on bends and T-joints due to multiphase flow

    NARCIS (Netherlands)

    Belfroid, S.P.C.; Cargnelutti, M.F.; Schiferli, W.; Osch, M.M.E. van

    2010-01-01

    To be able to assess the mechanical integrity of piping structures for loading to multiphase flow conditions, air-water experiments were carried out in a horizontal 1" pipe system. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating

  10. Adaptation of multi-joint balance coordination to whole body force fields

    NARCIS (Netherlands)

    Engelhart, Denise; Schouten, Alfred; Aarts, Ronald; Pasma, J.; Meskers, Carel; Maier, Andrea; Kooij, van der Herman

    2014-01-01

    Background and aim: The ankles and the hips play an important role in standing balance. Multi-joint coordination adapts with task, the magnitude and type of disturbance [1]. Arm studies show that postural responses are highly dependent on externally applied force fields [2]. Our aim is to study how

  11. Quantitative assessment of lumber facet joints and intervertebral discs with axial MR T 2 star mapping%轴位 MRT2*m apping 对腰椎小关节和椎间盘的定量研究

    Institute of Scientific and Technical Information of China (English)

    曹观美; 赵斌

    2014-01-01

    目的:探讨轴位腰椎小关节和椎间盘M R T2*mapping成像的可行性,明确T2*mapping定量成像技术对小关节和椎间盘早期退变的评估价值。方法收集慢性下腰痛患者22名作为病例组,性别和年龄匹配的健康志愿者20名为正常对照组,采用3.0T M RI对两组行T2*mapping及常规T2 WI成像,根据Weishaupt分级法、Pfirrmann分级法分别对L2~ S1各节段小关节和椎间盘进行形态学分级,并测量小关节和椎间盘的 T2*值,进行对比分析。结果不同Weishaupt分级小关节的T2*值差异无统计学意义( P>0.05)。不同Pfirrmann分级椎间盘髓核的T2*值差异有统计学意义( P <0.05)。小关节与后纤维环的T 2*值呈弱相关性( r‐0.3874)。病例组与对照组小关节的 T 2*值很相近,而髓核的T2*值差异有统计学意义( P <0.05)。在小关节评价的组间一致性方面,T2*值的一致性很好( r =0.835,P <0.05);形态学Weishaupt分级一致性较差(kappa=0.327)。结论此研究表明T2* mapping可用于软骨的定量研究,且轴位的腰椎小关节和椎间盘T2*mapping联合成像是可行的。%Objective To value the feasibility of MR T2 star mapping of lumbar facet joints and intervertebral discs ,and to evaluate the diagnostic value of T 2 star mapping in early‐stage degeneration of lumbar facet joints and intervertebral discs .Methods 22 patients with low back pain and 20 age‐and sex‐matched volunteers were examined .T2 star mapping and fast spin echo T2WI of lumber facet joints and intervertebral discs were evaluated with a 3 .0 T MR imaging spectrom‐eter in 42 subjects .The Weishaupt grading was used for L2 ~S1 facet joints and the pfirrmann score was used for morpho‐logical disc grading .T2 star value in the facet joints and the intervertebral discs were measured respectively in T 2 star map‐ping imaging ,and the correlation of them and variance in

  12. Hip joint contact forces in normal subjects and subjects with total hip prostheses: walking and stair and ramp negotiation.

    Science.gov (United States)

    Stansfield, B W; Nicol, A C

    2002-02-01

    To calculate the hip joint contact force in normal subjects and subjects with total hip replacements. An observational study of age matched normal subjects and subjects with hip joint replacements. Hip joint contact forces have been calculated using musculo-skeletal models and measured in vivo using instrumented hip prostheses. There are few examples of studies performed on subjects in the 40-60 year age range. This study characterises the forces in both normal subjects and subjects with hip joint replacements for these 'young' subjects. Motion analysis and force plate data were used as input to a three-dimensional model of the leg. Five male and six female normal subjects and five male subjects with hip prostheses were studied. Each subject was observed walking and negotiating stairs and a ramp. Hip joint contact forces in both thigh and pelvic-based co-ordinate systems are presented. Subjects cadence, speed and stride length are given. In general subjects with hip replacements exhibited lower hip joint contact forces than age matched normal subjects. It is suggested that this was the results of the lower speeds, stride lengths and cadences adopted by the subjects with hip replacements. The characterisation of hip joint contact forces provides essential information for prosthetic joint design and testing. The comparison of hip joint contact forces in normal subjects with those in subjects with prosthetic joints provides evidence of, not only actual use of joints, but also of possible levels of force that might be applied to hip prostheses if subjects returned to normal use.

  13. Biomechanics of first ray hypermobility: an investigation on joint force during walking using finite element analysis.

    Science.gov (United States)

    Wong, Duo Wai-Chi; Zhang, Ming; Yu, Jia; Leung, Aaron Kam-Lun

    2014-11-01

    Hypermobility of the first ray is suggested to contribute to hallux valgus. The investigation of first ray hypermobility focused on the mobility and range of motion that based on manual examination. The load transfer mechanism of the first ray is important to understand the development and pathomechanism of hallux valgus. In this study, we investigated the immediate effect of the joint hypermobility on the metatarsocuneiform and metatarsophalangeal joint loading through a reduction of the stiffness of the foot ligaments. A three-dimensional foot model was constructed from a female aged 28 via MRI. All foot and ankle bones, including two sesamoids and the encapsulated bulk tissue were modeled as 3D solid parts, linking with ligaments of shell elements and muscles connectors. The stance phase of walking was simulated by the boundary and loading conditions obtained from gait analysis of the same subject. Compared with the normal foot, the hypermobile foot had higher resultant metatarsocuneiform and metatarsophalangeal joint forces. The increases accounted for 18.6% and 3.9% body weight. There was also an abrupt change of metatarsocuneiform joint force in the medial-lateral direction. The predicted results represented possible risk of joint problems and metatarsus primus varus.

  14. Organizing for Effective Joint Warfare: A Deductive Analysis of U.S. Armed Forces Joint Doctrine

    Science.gov (United States)

    1993-06-18

    years the military has modified the concept of control from that conceived by the classical management theorist, Henri Fayol . It has evolved from a...methodology used in Henry C. Bartlett’s, and 0. Paul Holman, Jr’s. "Strategy As a Guide to Force Planning", Naval War College Review, Vcl XLI, No. 4...8217 Unpublished SAMS Monogram, U.S. Army Command and (eneral Staff College, Fort Leavenworth, KS: 1988. Bartlett, Henry C. and Holman, 0. Paul Jr. "Strategy As

  15. Influence of the 3D inverse dynamic method on the joint forces and moments during gait.

    Science.gov (United States)

    Dumas, R; Nicol, E; Chèze, L

    2007-10-01

    The joint forces and moments are commonly used in gait analysis. They can be computed by four different 3D inverse dynamic methods proposed in the literature, either based on vectors and Euler angles, wrenches and quaternions, homogeneous matrices, or generalized coordinates and forces. In order to analyze the influence of the inverse dynamic method, the joint forces and moments were computed during gait on nine healthy subjects. A ratio was computed between the relative dispersions (due to the method) and the absolute amplitudes of the gait curves. The influence of the inverse dynamic method was negligible at the ankle (2%) but major at the knee and the hip joints (40%). This influence seems to be due to the dynamic computation rather than the kinematic computation. Compared to the influence of the joint center location, the body segment inertial parameter estimation, and more, the influence of the inverse dynamic method is at least of equivalent importance. This point should be confirmed with other subjects, possibly pathologic, and other movements.

  16. Endoscopic Facet Debridement for the treatment of facet arthritic pain - a novel new technique

    Directory of Open Access Journals (Sweden)

    Scott M.W. Haufe, Anthony R. Mork

    2010-01-01

    Full Text Available Study design: Retrospective, observational, open label. Objective: We investigated the efficacy of facet debridement for the treatment of facet joint pain. Summary of background data: Facet joint disease, often due to degenerative arthritis, is common cause of chronic back pain. In patients that don't respond to conservative measures, nerve ablation may provide significant improvement. Due to the ability of peripheral nerves to regenerate, ablative techniques of the dorsal nerve roots often provide only temporary relief. In theory, ablation of the nerve end plates in the facet joint capsule should prevent reinnervation. Methods: All patients treated with endoscopic facet debridement at our clinic from 2003-2007 with at least 3 years follow-up were included in the analysis. Primary outcome measure was percent change in facet-related pain as measured by Visual Analog Scale (VAS score at final follow-up visit. Results: A total of 174 people (77 women, 97 men; mean age 64, range 22-89 were included. Location of facet pain was cervical in 45, thoracic in 15, and lumbar in 114 patients. At final follow-up, 77%, 73%, and 68% of patients with cervical, thoracic, or lumbar disease, respectively, showed at least 50% improvement in pain. Mean operating time per joint was 17 minutes (range, 10-42. Mean blood loss was 40 ml (range, 10-100. Complications included suture failure in two patients, requiring reclosure of the incision. No infection or nerve damage beyond what was intended occurred. Conclusions: Our results demonstrate a comparable efficacy of endoscopic facet debridement compared to radiofrequency ablation of the dorsal nerve branch, with durable results. Large scale, randomized trials are warranted to further evaluate the relative efficacy of this surgical treatment in patients with facet joint disease.

  17. Forces in bolted joints: analysis methods and test results utilized for nuclear core applications (LWBR Development Program)

    Energy Technology Data Exchange (ETDEWEB)

    Crescimanno, P.J.; Keller, K.L.

    1981-03-01

    Analytical methods and test data employed in the core design of bolted joints for the LWBR core are presented. The effects of external working loads, thermal expansion, and material stress relaxation are considered in the formulation developed to analyze joint performance. Extensions of these methods are also provided for bolted joints having both axial and bending flexibilities, and for the effect of plastic deformation on internal forces developed in a bolted joint. Design applications are illustrated by examples.

  18. Advance Force Operations: The Middleweight Force’s Essential Role in the Joint Operations

    Science.gov (United States)

    2013-04-18

    struck offshore coral reefs and other obstacles in the surf; many Marines drowned or succumbed to enemy fire when their landing craft could not reach...Joint Chiefs of Staff and the primary responsibilities of the US Marine Corps.35 …the destruction of hostile weather and radar stations, destruction of...enemy submarine base facilities, destruction of enemy air base facilities, destruction of critical enemy industrial plants or raw materials

  19. 手法整复胸腰椎后关节紊乱治疗腰背肌筋膜疼痛综合征%TREATING BACK MYOFASCIAL PAIN SYNDROME BY MAINPULATION OF THORACOLUMBAR FACET JOINT DISORDER

    Institute of Scientific and Technical Information of China (English)

    马永健; 王强; 张丽娜

    2012-01-01

    Objective To observe the clinical effect of the mainpulation of thoracolumbar facet joint disorder in treating back myofascial pain syndrome and its influence on the serum level of interleukin -1( IL - 1 ). Methods A total of 120 patients were randomly divided into treatment and control groups, the treatment group was treated by mainpulation and the control group was treated with oral Ibuprofen and Eperisone, the changes of clinical symptoms 、signs and the serum level IL - 1 were observed. Results The treatment group had obvious advantages in the total clinical effect, but not very different from the control group in lowering the serum level IL -1. Conclusion The thoracolumbar facet joint disorder is a major pathological change of back myofascial pain syndrome, and the mainpulation of thoracolumbar facet joint disorder has a good and lasting effect.%目的 观察手法整复胸腰椎后关节紊乱治疗腰背肌筋膜疼痛综合征的临床疗效及对血清白细胞介素(interleukin-1,IL-1)含量的影响.方法 患者120例,随机分成治疗组和对照组,分别采用手法整复胸腰椎后关节紊乱治疗和精氨酸布洛芬颗粒+乙哌立松片治疗,观察治疗前后临床症状、体征及血清IL-1含量的变化.结果 治疗组总疗效优于对照组(P<0.01),在降低血清IL-1含量方面与对照组差异无统计学意义(P>0.05).结论 胸腰椎后关节紊乱是腰背肌筋膜疼痛综合征一个重要病理改变,手法整复胸腰椎后关节紊乱在临床取得良好疗效且作用持久.

  20. An observational feasibility study to assess the safety and effectiveness of intranasal fentanyl for radiofrequency ablations of the lumbar facet joints

    Science.gov (United States)

    Bartoszek, Michael W; McCoart, Amy; Hong, Kyung-soo Jason; Haley, Chelsey; Highland, Krista Beth; Plunkett, Anthony R

    2017-01-01

    Purpose The purpose of the present observational, feasibility study is to assess the preliminary safety and effectiveness of intranasal fentanyl for lumbar facet radiofrequency ablation procedures. Patients and methods This cohort observational study included 23 adult patients. Systolic and diastolic blood pressures, heart rate, oxygen saturation percent, Pasero Opioid-Induced Sedation Scale score, and the Defense and Veterans Pain Rating Scale pain score were assessed prior to the procedure and intranasal fentanyl (100 μg) administration and every 15 minutes after administration, up to 60 minutes post administration. Follow-up of patient satisfaction with pain control and treatment was assessed 24 hours after discharge. The primary outcome was safety as evidenced by adverse events. Secondary outcomes included the above-mentioned vital signs and pain ratings. Results No adverse events occurred in the present study and all participants maintained an acceptable level of awareness throughout the assessment period. One-way repeated measures analyses of covariance tests with Bonferroni-adjusted means indicated that oxygen saturation, blood pressure, and heart rate changed from baseline, whereas pain scores were lower at post-administration levels compared with baseline. Finally, the majority of participants reported being satisfied with pain control and treatment. Conclusion Preliminary evidence indicates that intranasal fentanyl is safe and effective for lumbar facet radiofrequency ablation procedures. Future rigorous randomized control trials are needed to confirm the present results and to examine the effects of intranasal fentanyl on intraoperative and postoperative opioid use.

  1. Finnishing the Force: Achieving True Flexibility for the Joint Force Commander

    Science.gov (United States)

    2014-06-01

    CREW) 2.1 vehicle-mounted jammer (up to 25,000 of which are on contract for purchase by the US Army). It uses a digitally controlled, 30-watt...out assigned tasks. We may no longer be able to afford the luxury of retaining our most sophisticated capabilities as or- ganic elements of a...joint force” (II-7). 2. “JCREW: ITT Wins Contracts for Land Mine Jammers,” Defense Industry Daily, 3 Octo- ber 2011, http://www.defenseindustrydaily.com

  2. Final Environmental Assessment: Replacement Joint Force Headquarters Building, Hanscom Air Force Base Massachusetts

    Science.gov (United States)

    2010-01-22

    occupies building 1503 with the State Medical Command (Med Com). Med Com plans, programs, provides, and sustains health force protection and medical/ dental ...Center for Health Promotion and Preventative Medicine (USACHPPM) Dempsey, Judith; Polyak , Lisa; Tushek, Stephen. Technical Guide for Preparing a... Polyak , Lisa; Tushek, Stephen. Technical Guide for Preparing a Record of Nonapplicability for the General Conformity Rule. November 2003. USEPA. AP 42

  3. Trunk-pelvis motion, joint loads, and muscle forces during walking with a transtibial amputation.

    Science.gov (United States)

    Yoder, Adam J; Petrella, Anthony J; Silverman, Anne K

    2015-03-01

    People with unilateral, transtibial amputation (TTA) have an increased prevalence of chronic low back pain (LBP) relative to able-bodied people. However, a definitive cause of increased LBP susceptibility has not been determined. The purpose of this work was to compare dynamic trunk-pelvis biomechanics between people with (n=6) and without (n=6) unilateral TTA during walking using a computational modeling approach. A generic, muscle-actuated whole body model was scaled to each participant, and experimental walking data were used in a static optimization framework to calculate trunk-pelvis motion, L4L5 joint contact forces, and muscle forces within the trunk-pelvis region. Results included several significant between-group differences in trunk-pelvis biomechanics during different phases of the gait cycle. Most significant was greater lateral bending toward the residual side during residual single-limb stance (p<0.01), concurrent with an elevated L4L5 joint contact force (p=0.02) and greater muscle force from the intact-side obliques (p<0.01) in people with TTA relative to able-bodied people. During both double-limb support phases, people with TTA also had a greater range of axial trunk rotation away from the leading limb, concurrent with greater ranges of muscle forces in the erector spinae and obliques. In addition, a greater range of force (p=0.03) in residual-side psoas was found during early residual limb swing in people with TTA. Repeated exposure to atypical motion and joint/muscle loading in people with TTA may contribute to the development of secondary musculoskeletal disorders, including chronic, mechanical LBP.

  4. Clinical Observation on the Efficacy of Thoracic Facet Joint Disorder Treated with Electroacupuncture and Manual Reduction%电针联合手法整复对胸椎小关节紊乱患者临床观察

    Institute of Scientific and Technical Information of China (English)

    杨炎珠; 李子勇

    2015-01-01

    Objective To compare the efficacy and pain alleviation of thoracic facet joint disorder treated with electroacupuncture combined with manual reduction and merely manual reduction, so as to provide clinical evidence for treating thoracic facet joint disor-der with electroacupuncture and manual reduction. Methods 84 patients with thoracic facet joint disorder in our hospital from April 2013 to June 2014 were randomly divided into the observation group ( treated with electroacupuncture and manual reduction) and the control group ( treated merely with manual reduction) , with 42 cases in each group respectively. Differences of clinic efficacy and pain alleviation of the two groups were compared. Results The curative rate and the total effective rate of the observation group were 54. 76% and 95. 24% respectively, higher than that (19. 05% and 76. 19%) of the control group. PRI, VAS, PPI differed before and after treatment of the two groups, with statistically significant difference (P<0. 05). Conclusion As for treating thoracic facet joint disorder, the method of electroacupuncture combined with manual reduction proves to be more efficient than merely manual reduc-tion, and can reduce the pain of patients, which is worthy of clinical application and promotion.%目的:比较电针联合手法整复治疗与单纯手法治疗胸椎小关节紊乱患者的临床疗效及疼痛改善情况,为电针联合手法整复治疗胸椎小关节紊乱提供临床依据。方法将2013年4月至2014年6月于我院针灸科门诊进行治疗的84例胸椎小关节紊乱患者随机分为对照组和观察组各42例,对照组采用单纯手法治疗,观察组使用电针联合手法整复治疗。比较两者患者在临床疗效及治疗前后疼痛改善情况的差异。结果观察组治愈率和总有效率分别为54.76%和95.24%,显著高于对照组的19.05%及76.19%(P<0.05);观察组患者PRI、 VAS、 PPI治疗前后差值与对照组PRI、 VAS、 PPI治疗前

  5. Force-Sensing Actuator with a Compliant Flexure-Type Joint for a Robotic Manipulator

    Directory of Open Access Journals (Sweden)

    Mathieu Grossard

    2015-12-01

    Full Text Available This paper deals with the mechatronic design of a novel self-sensing motor-to-joint transmission to be used for the actuation of robotic dexterous manipulators. Backdrivability, mechanical simplicity and efficient flexure joint structures are key concepts that have guided the mechanical design rationale to provide the actuator with force sensing capabilities. Indeed, a self-sensing characteristic is achieved by the specific design of high-resolution cable-driven actuators based on a DC motor, a ball-screw and a monolithic compliant anti-rotation system together with a novel flexure pivot providing a frictionless mechanical structure. That novel compliant pivot with a large angular range and a small center shift has been conceived of to provide the inter-phalangeal rotational degree of freedom of the fingers’ joints to be used for integration in a multi-fingered robotic gripper. Simultaneously, it helps to remove friction at the joint level of the mechanism. Experimental tests carried out on a prototype show an accurate matching between the model and the real behavior. Overall, this mechatronic design contributes to the improvement of the manipulation skills of robotic grippers, thanks to the combination of high performance mechanics, high sensitivity to external forces and compliance control capability.

  6. Airpower in Hybrid War: Ethical Implications for the Joint Force Commander

    Science.gov (United States)

    2014-05-15

    building housing three adversaries designated as a high value target. However, in this scenario ten children also live in the building. One targeting option...makes bridging tactics and strategy extremely difficult. The character of hybrid war will likely contain an enemy with an intangible center of gravity ...Law” def. 1, accessed 15 May 2014. 4 Kevin M. Brew , “Legal Basis for use of Force and Law of Armed Conflict,” U.S. Naval War College, Joint

  7. The Effects of Force and Joint Angle on Muscle Conduction Velocity Estimation

    Science.gov (United States)

    2007-11-02

    Institute of Biomedical Engineering, University of New Brunswick Abstract - Conduction velocity estimated from the surface myoelectric signal has been...changes in joint angle and/or muscle force. Results from this study using myoelectric signals collected from the biceps brachii, indicate that conduction... myoelectric signal (MES) to track changes in muscle biochemistry which are caused by fatigue. By estimating the power spectrum of the surface MES during

  8. A Joint Force Medical Command is Required to Fix Combat Casualty Care

    Science.gov (United States)

    2017-10-05

    all-volunteer military and similar programs evolved to train the majority of medical specialists the military required ranging from medics to nurse ...surgery, nursing , pharmacy, radiology and laboratory services, and also have a basic understanding of what a hospital does when it is established...A Joint Force Medical Command is Required to Fix Combat Casualty Care by Colonel Shawn C. Nessen United States Army Pr og ra

  9. Aviation Security Force Assistance: Joint General Purpose Forces as Air Advisors

    Science.gov (United States)

    2013-03-01

    David E. Thaler et al., Building Partner Health Capacity with U.S. Military Forces: Enhancing AFSOC Health Engagement Missions (Santa Monica, CA: RAND...language, and diplomacy.” 36 Similarly, the advisor must be careful to avoid demonstrating frustration with host nation personnel and must be...Africa. 12 USAFRICOM conducted the first APF event in Accra, Ghana in March, 2012, with participation of service members from Ghana , Togo, Benin

  10. Sound side joint contact forces in below knee amputee gait with an ESAR prosthetic foot.

    Science.gov (United States)

    Karimi, Mohammad Taghi; Salami, Firooz; Esrafilian, Amir; Heitzmann, Daniel W W; Alimusaj, Merkur; Putz, Cornelia; Wolf, Sebastian I

    2017-08-08

    The incidence of knee and hip joint osteoarthritis in subjects with below knee amputation (BK) appears significantly higher compared to unimpaired subjects, especially in the intact side. However, it is controversial if constant higher loads on the sound side are one of the major factors for an increased osteoarthritis (OA) incidence in subjects with BK, beside other risk factors, e.g. with respect to metabolism. The aim wasto investigate joint contact forces (JCF) calculated by a musculoskeletal model in the intact side and to compare it with those of unimpaired subjects and to further elucidate in how far increased knee JCF are associated with increased frontal plane knee moments. A group of seven subjects with BK amputation and a group of ten unimpaired subjects were recruited for this study. Gait data were measured by 3D motion capture and force plates. OpenSim software was applied to calculate JCF. Maximum joint angles, ground reaction forces, and moments as well as time distance parameters were determined and compared between groups showing no significant differences, with some JCF components of knee and hip even being slightly smaller in subjects with BK compared to the reference group. This positive finding may be due to the selected ESAR foot. However, other beneficial factors may also have influenced this positive result such as the general good health status of the subjects or the thorough and proper fitting and alignment of the prosthesis. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity

    NARCIS (Netherlands)

    DeVita, Paul; Rider, Patrick; Hortobagyi, Tibor

    A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The

  12. 成人颈椎小关节间隙穿刺路径的应用解剖%Clinical anatomy of the facet joint puncture in adult cervical vertebra

    Institute of Scientific and Technical Information of China (English)

    张贵源; 朱文仁; 杨兵; 闫军浩; 王建伟; 张卫光

    2012-01-01

    Objective To study the type, the angle and the obliquity of facet joints and to identify the approach for the facet joint puncture in adult cervical vertebra. Methods Thirty eight spines of 27 male and 11 female cadavers were used to observe the type and angle of C2-3-C6-7 on the transverse section. The obliquity and shape of the facet joint were also studied in 40 adult cadaveric spines. Results The joints in C2-3-C6-7 were classified as the plane oval(79. 2% ) or curved surface(20. 8% ) types. The joint angles and articular processes were gradually increased from C2-3 to C6-7. The obliquities of joint planes were C3 > C4 > C5 < C6 < C7 , and their values were distributed as a " U" shape. The middle part of the joints was located at the outside of the posterior midline and at the midpoints between spinous processes of cervical vertebra. The distance from the middle part to the posterior midline increased gradually downward from 17. 19mm, 17.51mm, 18.76mm, 19.83mm to 20.52mm. The tissue layers during the puncture approach went through skin, superficial fascia, ligamentum nuchae, splenius capitis muscle and the posterior of joint capsule. Conclusion In adult cervical vertebra, facet joint puncture should be performed at the outside ( 17. 2-20. 5mm) of the midpoint between corresponding cervical space according to the type, the angle and the obliquity of joint plane. The puncture direction should be caudally tilted at 55°-67°( average 60°)and advanced obliquely cranially.%目的 探讨颈椎小关节的关节类型、关节角大小、关节面倾角等,为临床行颈椎间隙穿刺提供可参考的路径.方法 采用正常成人脊柱标本38例(男27、女11),通过断层解剖方法,从横断面上对C2-3~C6-7关节类型、关节角进行观测,并对40套成人椎骨标本的颈椎小关节关节面倾角及形态进行观测.结果 C2-33~C6-7关节类型主要为平面椭圆形(79.2%)和曲面形(20.8%);自C2-3至C6-7颈椎关节突的关节角

  13. Effect of Chord Splice Joints on Force Distribution and Deformations in Trusses with Punched Metal Plate Fasteners

    DEFF Research Database (Denmark)

    Ellegaard, Peter

    2007-01-01

    The span of roof trusses with punched metal plate fasteners (nail plates) makes it often necessary to use splice joints in the top and bottom chords. In the finite element models used for design of the trusses these splice joints are normally assumed to be either rotationally stiff or pinned - th...... of splice joints on section forces and displacements are discussed considering the results from finite element calculations for a fink truss. It seems that the guidelines for treating splice joints as rotationally stiff do not necessarily lead to more realistic truss models....... - their real behaviour is semi-rigid. The influence of splice joints on the distribution of member forces and rotations in the splice joints is investigated in this paper. A finite element program, TrussLab, where the splice joints are given semi-rigid properties is used to analyse the effect of splice joints...... if their deformation has no significant effect upon the distribution of member forces according to Eurocode 5. Two simple guidelines for the design and location of splice joints are given in Eurocode 5 for treating the splice joints as rotationally stiff. The reasonability of these guidelines and the influence...

  14. Analysis of knee-joint forces during flexed-knee stance.

    Science.gov (United States)

    Perry, J; Antonelli, D; Ford, W

    1975-10-01

    Using an instrumented cadaver lower extremity, the forces in the quadriceps, patella, and tibia during flexed-knee stance were measured and the calculated and experimental data were found to correlate with an average discrepancy of 6 per cent. The quadriceps force required to stabilize the knee was 75 per cent of the load on the femoral head at 15 degrees of knee flexion, 210 per cent at 30 degrees, and 410 per cent at 60 degrees. Stresses at the tibiofemoral and patellofemoral joint surfaces increased in similar fashion. The quadriceps force was equivalent to 20 per cent of average maximum quadriceps strength at 15 degrees and to 50 per cent at 30 degrees, as determined from torque tests on five normal subjects.

  15. Effect of lateralized design on muscle and joint reaction forces for reverse shoulder arthroplasty.

    Science.gov (United States)

    Liou, William; Yang, Yang; Petersen-Fitts, Graysen R; Lombardo, Daniel J; Stine, Sasha; Sabesan, Vani J

    2017-04-01

    Manufacturers of reverse shoulder arthroplasty (RSA) implants have recently designed innovative implants to optimize performance in rotator cuff-deficient shoulders. These advancements are not without tradeoffs and can have negative biomechanical effects. The objective of this study was to develop an integrated finite element analysis-kinematic model to compare the muscle forces and joint reaction forces (JRFs) of 3 different RSA designs. A kinematic model of a normal shoulder joint was adapted from the Delft model and integrated with the well-validated OpenSim shoulder model. Static optimizations then allowed for calculation of the individual muscle forces, moment arms, and JRFs relative to net joint moments. Three-dimensional computer models of 3 RSA designs-humeral lateralized design (HLD), glenoid lateralized design, and Grammont design-were integrated, and parametric studies were performed. Overall, there were decreases in deltoid and rotator cuff muscle forces for all 3 RSA designs. These decreases were greatest in the middle deltoid of the HLD model for abduction and flexion and in the rotator cuff muscles under both internal rotation and external rotation. The JRFs in abduction and flexion decreased similarly for all RSA designs compared with the normal shoulder model, with the greatest decrease seen in the HLD model. These findings demonstrate that the design characteristics implicit in these modified RSA prostheses result in mechanical differences most prominently seen in the deltoid muscle and overall JRFs. Further research using this novel integrated model can help guide continued optimization of RSA design and clinical outcomes. Copyright © 2017 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.

  16. Subject-specific hip geometry affects predicted hip joint contact forces during gait.

    Science.gov (United States)

    Lenaerts, G; De Groote, F; Demeulenaere, B; Mulier, M; Van der Perre, G; Spaepen, A; Jonkers, I

    2008-01-01

    Hip loading affects bone remodeling and implant fixation. In this study, we have analyzed the effect of subject-specific modeling of hip geometry on muscle activation patterns and hip contact forces during gait, using musculoskeletal modeling, inverse dynamic analysis and static optimization. We first used sensitivity analysis to analyze the effect of isolated changes in femoral neck-length (NL) and neck-shaft angle (NSA) on calculated muscle activations and hip contact force during the stance phase of gait. A deformable generic musculoskeletal model was adjusted incrementally to adopt a physiological range of NL and NSA. In a second similar analysis, we adjusted hip geometry to the measurements from digitized radiographs of 20 subjects with primary hip osteoarthrosis. Finally, we studied the effect of hip abductor weakness on muscle activation patterns and hip contact force. This analysis showed that differences in NL (41-74 mm) and NSA (113-140 degrees ) affect the muscle activation of the hip abductors during stance phase and hence hip contact force by up to three times body weight. In conclusion, the results from both the sensitivity and subject-specific analysis showed that at the moment of peak contact force, altered NSA has only a minor effect on the loading configuration of the hip. Increased NL, however, results in an increase of the three hip contact-force components and a reduced vertical loading. The results of these analyses are essential to understand modified hip joint loading, and for planning hip surgery for patients with osteoarthrosis.

  17. Biofeedback for Gait Retraining Based on Real-Time Estimation of Tibiofemoral Joint Contact Forces.

    Science.gov (United States)

    Pizzolato, Claudio; Reggiani, Monica; Saxby, David J; Ceseracciu, Elena; Modenese, Luca; Lloyd, David G

    2017-09-01

    Biofeedback assisted rehabilitation and intervention technologies have the potential to modify clinically relevant biomechanics. Gait retraining has been used to reduce the knee adduction moment, a surrogate of medial tibiofemoral joint loading often used in knee osteoarthritis research. In this paper, we present an electromyogram-driven neuromusculoskeletal model of the lower-limb to estimate, in real-time, the tibiofemoral joint loads. The model included 34 musculotendon units spanning the hip, knee, and ankle joints. Full-body inverse kinematics, inverse dynamics, and musculotendon kinematics were solved in real-time from motion capture and force plate data to estimate the knee medial tibiofemoral contact force (MTFF). We analyzed five healthy subjects while they were walking on an instrumented treadmill with visual biofeedback of their MTFF. Each subject was asked to modify their gait in order to vary the magnitude of their MTFF. All subjects were able to increase their MTFF, whereas only three subjects could decrease it, and only after receiving verbal suggestions about possible gait modification strategies. Results indicate the important role of knee muscle activation patterns in modulating the MTFF. While this paper focused on the knee, the technology can be extended to examine the musculoskeletal tissue loads at different sites of the human body.

  18. A modeling approach to compute modification of net joint forces caused by coping movements in obstetric brachial plexus palsy

    OpenAIRE

    2013-01-01

    Background Many disorders of the musculoskeletal system are caused by modified net joint forces resulting from individual coping movement strategies of patients suffering from neuromuscular diseases. Purpose of this work is to introduce a personalized biomechanical model which allows the calculation of individual net joint forces via inverse dynamics based on anthropometry and kinematics of the upper extremity measured by 3D optoelectronical motion analysis. Methods The determined resulting n...

  19. The Joint Force Air Component Commander and the Integration of Offensive Cyberspace Effects: Power Projection through Cyberspace

    Science.gov (United States)

    2016-06-14

    86 | Air & Space Power Journal The Joint Force Air Component Commander and the Integration of Offensive Cyberspace Effects Power Projection through...and Space Power Journal requests a courtesy line. Cyberspace can provide great opportunities to assist the joint force air compo-nent commander (JFACC...in theory. Offensive cyberspace operations have the potential to provide these types of power - projecting effects in the battlespace, but how can

  20. Evaluation and Treatment of Lumbar Facet Cysts.

    Science.gov (United States)

    Boody, Barrett S; Savage, Jason W

    2016-12-01

    Lumbar facet cysts are a rare but increasingly common cause of symptomatic nerve root compression and can lead to radiculopathy, neurogenic claudication, and cauda equina syndrome. The cysts arise from the zygapophyseal joints of the lumbar spine and commonly demonstrate synovial herniation with mucinous degeneration of the facet joint capsule. Lumbar facet cysts are most common at the L4-L5 level and often are associated with spondylosis and degenerative spondylolisthesis. Advanced imaging studies have increased diagnosis of the cysts; however, optimal treatment of the cysts remains controversial. First-line treatment is nonsurgical management consisting of oral NSAIDs, physical therapy, bracing, epidural steroid injections, and/or cyst aspiration. Given the high rate of recurrence and the relatively low satisfaction with nonsurgical management, surgical options, including hemilaminectomy or laminotomy to excise the cyst and decompress the neural elements, are typically performed. Recent studies suggest that segmental fusion of the involved levels may decrease the risks of cyst recurrence and radiculopathy.

  1. An Unexplored Facet of International Business in Greece: Foreign and Diaspora Shareholders in Joint Stock Company Start-Ups, 1833-1920

    Directory of Open Access Journals (Sweden)

    Ioanna Sapfo Pepelasis

    2016-07-01

    Full Text Available This paper focuses on an unexplored aspect of the history of international business in Greece, the presence of international shareholders in Greek Joint stock company start-ups. Our main findings are that these investors participated in numerous such firms usually as minority shareholders in capital and or knowledge intensive firms. Rarely did they opt for the exclusive international ownership of a joint stock company in Greece and the dividing line  between foreign direct investment and foreign portfolio investment was not always clear. It is also the case that international capital inflow into the nascent corporate sector involved a mosaic of collaborating actors including not only the foreign but also the diasporic.

  2. Ground reaction forces and lower-limb joint kinetics of turning gait in typically developing children.

    Science.gov (United States)

    Dixon, Philippe C; Stebbins, Julie; Theologis, Tim; Zavatsky, Amy B

    2014-11-28

    Turning is a common locomotor task essential to daily activity; however, very little is known about the forces and moments responsible for the kinematic adaptations occurring relative to straight-line gait in typically developing children. Thus, the aims of this study were to analyse ground reaction forces (GRFs), ground reaction free vertical torque (TZ), and the lower-limb joint kinetics of 90° outside (step) and inside (spin) limb turns. Step, spin, and straight walking trials from fifty-four typically developing children were analysed. All children were fit with the Plug-in Gait and Oxford Foot Model marker sets while walking over force plates embedded in the walkway. Net internal joint moments and power were computed via a standard inverse dynamics approach. All dependent variables were statistically analysed over the entire curves using the mean difference 95% bootstrap confidence band approach. GRFs were directed medially for step turns and laterally for spin turns during the turning phase. Directions were reversed and magnitudes decreased during the approach phase. Step turns showed reduced ankle power generation, while spin turns showed large TZ. Both strategies required large knee and hip coronal and transverse plane moments during swing. These kinetic differences highlight adaptations required to maintain stability and reorient the body towards the new walking direction during turning. From a clinical perspective, turning gait may better reveal weaknesses and motor control deficits than straight walking in pathological populations, such as children with cerebral palsy, and could potentially be implemented in standard gait analysis sessions.

  3. AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training.

    Science.gov (United States)

    Harkness, Beth A; Allison, Jerry D; Clements, Jessica B; Coffey, Charles W; Fahey, Frederic H; Gress, Dustin A; Kinahan, Paul E; Nickoloff, Edward L; Mawlawi, Osama R; MacDougall, Robert D; Pizzutiello, Robert J

    2015-09-08

    The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear  medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics  Training. The mission of this task force was to assemble a representative group of stakeholders to:• Estimate the demand for board-certified nuclear medicine physicists in the next 5-10 years,• Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, and• Identify approaches that may be considered to facilitate the training of nuclear medicine physicists.As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face-to-face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission.

  4. Effect of arm swinging on lumbar spine and hip joint forces.

    Science.gov (United States)

    Angelini, Lorenza; Damm, Philipp; Zander, Thomas; Arshad, Rizwan; Di Puccio, Francesca; Schmidt, Hendrik

    2017-09-14

    During level walking, arm swing plays a key role in improving dynamic stability. In vivo investigations with a telemeterized vertebral body replacement showed that spinal loads can be affected by differences in arm positions during sitting and standing. However, little is known about how arm swing could influence the lumbar spine and hip joint forces and motions during walking. The present study aims to provide better understanding of the contribution of the upper limbs to human gait, investigating ranges of motion and joint reaction forces. A three-dimensional motion analysis was carried out via a motion capturing system on six healthy males and five patients with hip instrumented implant. Each subject performed walking with different arm swing amplitudes (small, normal, and large) and arm positions (bound to the body, and folded across the chest). The motion data were imported in a commercial musculoskeletal analysis software for kinematic and inverse dynamic investigation. The range of motion of the thorax with respect to the pelvis and of the pelvis with respect to the ground in the transversal plane were significantly associated with arm position and swing amplitude during gait. The hip external-internal rotation range of motion statistically varied only for non-dominant limb. Unlike hip joint reaction forces, predicted peak spinal loads at T12-L1 and L5-S1 showed significant differences at approximately the time of contralateral toe off and contralateral heel strike. Therefore, arm position and swing amplitude have a relevant effect on kinematic variables and spinal loads, but not on hip loads during walking. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. One Size Does Not Fit All: How Acquisition Fails the Joint Force Commander

    Science.gov (United States)

    2010-04-02

    acquisition programs, such as the F-35, is worth the risk it presents to the nation by putting all ― eggs in one basket.‖ According to Joint Pub 1...Staff Procurement Backup Book: FY 2010 Budget Estimates, Research, Development, Test and Evaluation (RDT&E), Descriptive Summaries,‖ Vol. 3, May 2009...superiority fighter. This political climate caused the Air Force to recast the aircraft as a multi-role fighter and to scramble to add some air-to-ground

  6. Characteristics and clinical significance of declination angles on the lower cervical facet joints%颈椎关节突关节面倾角测量特点及临床意义

    Institute of Scientific and Technical Information of China (English)

    王怀云; 何海龙; 李华; 张桦; 朱云荣; 叶晓健

    2011-01-01

    Objective To measure the angle of declination on the lower cervical facet joints ( C3_7) in normal adults, and to investigate the range of normal values and the clinical significance. Methods A total of 500 X-ray films in cervical lateral position were randomly selected from normal outpatients. The angles of declination on the lower cervical facet joints ( C3-7 ) were measured by Unisight system. Results The angles of declination from C3 to C7 were 61. 9° ± 5. 4°, 54. 8° ± 4. 7°, 50.7° ±4.9°, 55.8° ±5.1°, and 63.4° ±5.3°, respectively. The distribution of angle values from C3 to C7 appeared in a " U" shape with the minimum value at C5 and the maximum values at C7. The mean angles of declination were above 45°. Statistical analysis indicated that the values of declination angle were as follows: C7 > C3 > C4 = C6 > C5. Conclusion The distribution characteristics of declination angles on the lower cervical facet joints can help to comprehend the biomechanics of cervical vertebra and the pathogenesis of diseases and trauma related to cervical vertebrae.%目的 观察正常成年人下颈椎关节突关节面倾斜角度测量特点,探讨其正常值范围及临床意义.方法 随机抽取门诊正常成年人颈椎侧位X线片500张,利用Unisight放射影像处理软件逐个测量其C3~7小关节突关节面倾角.结果 C3-7倾角大小依次分别为:61.9°±5.4°、54.8°±4.7°、50.7°±4.9°、55.8°±5.1°、63.4°±5.3°.C3~7倾角值大小呈“U”形分布,以C5最小,C7最大,各倾角均值>45°.经统计分析,各个下颈椎小关节突关节面倾角大小比较可以概括为C7>C3 >C4 =C6 >C5.结论 下颈椎小关节突关节面倾角不同,了解其分布特点有利于理解颈椎生物力学特性及相关颈椎疾病、颈椎外伤的发病机制.

  7. The senses of force and heaviness at the human elbow joint.

    Science.gov (United States)

    Brooks, Jack; Allen, Trevor J; Proske, Uwe

    2013-05-01

    The present-day view of the neural basis for the senses of muscle force and heaviness is that they are generated centrally, within the brain, from copies of motor commands. A corollary of the motor discharge generates a sense of effort which underlies these sensations. In recent experiments on force and heaviness sensations using thumb flexor muscles, a rather different explanation has been invoked: Subjects were proposed to rely predominantly on inputs of a peripheral origin, in particular, the signals of muscle spindles. The present experiments have been carried out at the elbow joint to determine whether these new ideas apply more widely. The effects of fatigue of elbow flexor muscles have been studied in force and heaviness matching tasks using three exercise regimes, a sustained maximum voluntary contraction (MVC), a maintained contraction of 35 % MVC, and a maintained contraction of 35 % MVC combined with muscle vibration at 80 Hz. In force-matching experiments, subjects were required to contract both arms and while the reference arm generated the target force under visual control, it was matched by the indicator arm without visual feedback. During the 100 % MVC exercise, force in the exercising reference arm fell rapidly to almost a half of its original value over 90 s while force in the indicator did not fall, leading to a significant overestimation of the reference force. During the 35 % MVC exercise, subjects also overestimated the reference force and this persisted at 5 and 10 min after the exercise. When 35 % MVC was combined with vibration, the amount by which the indicator arm overestimated the reference force was significantly reduced. In heaviness matching experiments, subjects could move their arms through a small range. The reference arm was loaded with a weight, and weights were added or removed from the indicator until heaviness felt the same in the two arms. There was a small, but significant fall in the matching weight used after 100 % MVC

  8. 针刺联合推拿手法治疗胸椎小关节紊乱的临床观察%Clinical observation on acupuncture combined with tuina manipulation for thoracic facet joint disorder

    Institute of Scientific and Technical Information of China (English)

    周光明; 姜军; 章燕

    2015-01-01

    目的:观察针刺联合推拿手法治疗胸椎小关节紊乱的临床疗效。方法:选取符合胸椎小关节紊乱诊断标准的患者93例,按就诊先后顺序随机分为观察组和对照组。观察组46例予以针刺联合推拿手法治疗,对照组47例予以单独推拿手法治疗。每日治疗1次,治疗3次后,以患者的症状及体征积分作为观察指标,进行临床疗效评价。结果:治疗后,两组患者8个症状或体征积分均与本组治疗前有统计学差异(均P<0.01);两组间评分差异亦均有统计学意义(均P<0.05)。治疗3次后,观察组治愈率为54.4%,对照组为25.4%,两组治愈率差异有统计学意义(P<0.05)。结论:针刺联合推拿手法治疗胸椎小关节紊乱疗效优于单独推拿手法治疗,值得临床推广。%Objective:To observe the clinical effect of acupuncture combined with tuina manipulation for thoracic facet joint disorder. Methods:A total of 93 eligible cases were randomly allocated into an observation group and a control group. Patients in the observation group (n=46) were treated with acupuncture combined with tuina manipulation, whereas patients in the control group (n=47) were treated with tuina manipulation alone. The treatment was done once a day, for a total of 3 times. Therapeutic efficacies were then evaluated according to scores on signs and symptoms. Results:After treatment, there were intra-group statistically significant differences in scores of eight signs and symptoms (all P Conclusion:Acupuncture combined with tuina manipulation can obtain better effects than tuina manipulation alone for thoracic facet joint disorder and is therefore worth further clinical application.

  9. Effects of masticatory muscle force on temporomandibular joint disc growth in rats.

    Science.gov (United States)

    Sakurai, Makoto; Yonemitsu, Ikuo; Muramoto, Takeshi; Soma, Kunimichi

    2007-12-01

    Biomechanical factors in masticatory function are related to the development of the mandible and the condyle. Previous studies have reported that reduced masticatory muscle force influences mandibular bone formation and chondroblastic proliferation. We examined the importance of compressive force in temporomandibular joint (TMJ) disc growth by reducing the masticatory load. Thirty 3-week-old male Wistar rats were used in this study. In the experimental group, the masseter muscles were bilaterally resected to evaluate the influence of masticatory muscle force on morphology and composition of TMJ disc during growth. No surgery was performed in the control group. The thickness of the TMJ disc was measured to evaluate the morphological changes. The localization of type I collagen and decorin was performed by immunostaining to examine compositional change. Cell proliferation in the disc was identified by insulin-like growth factor-1 receptor (IGF-1r) immunostaining. The disc thickness at each region in the experimental group was reduced compared to the control group. While in the control group, type I collagen and decorin were identified throughout the disc, it was concentrated on the superior portion of the disc at the anterior and posterior bands in the experimental group. The expression of IGF-1r immunopositive cells in the experimental group was also significantly lower than in the control. We conclude that masticatory muscle force is closely related to TMJ disc morphology and composition during growth.

  10. Joint strength measurements of individual fiber-fiber bonds: An atomic force microscopy based method

    Science.gov (United States)

    Schmied, Franz J.; Teichert, Christian; Kappel, Lisbeth; Hirn, Ulrich; Schennach, Robert

    2012-07-01

    We are introducing a method to measure tensile strength of individual fiber-fiber bonds within a breaking force range of 0.01 mN-1 mN as well as the energy consumed during breaking. Until now, such a method was not available. Using a conventional atomic force microscope and a specifically designed sample holder, the desired force and the breaking behavior can be analyzed by two different approaches. First, dynamic loading can be applied, where force-versus-distance curves are employed to determine the proportions of elastic energy and energy dissipated in the bond. Second, static loading is utilized to study viscoelastic behavior and calculate viscoelastic energy contributions. To demonstrate the capability of the proposed method, we are presenting results for breaking strength of kraft pulp fiber-fiber bonds in tensile opening mode. The procedure is by no means restricted to cellulose fibers, it has the potential to quantify joint strength of micrometer-sized fibers in general.

  11. Universal Resource Interface Module (URIM) for the Joint Force Protection Advanced Security System (JFPASS)

    Science.gov (United States)

    Cutler, S. H.; Cruickshanks, J. R.; Barngrover, C. M.; Kramer, T. A.; Nans, A. F.

    2009-05-01

    The Joint Force Protection Advanced Security System (JPFASS) is a Department of Defense effort to improve conventional force protection. It is sponsored and managed by Joint Program Manager - Guardian (JPM-G). The main objective of JFPASS is to provide an integrated and layered base defense system, which includes data fusion, Command and Control (C2) nodes, Common Operation Picture (COP) nodes, and full integration of a selected range of robots, sensors, cameras, weapons, tracking systems, and other C2 systems. The URIM is the main integration tool for several sensors, cameras, and weapons in JFPASS. The Universal Resource Interface Module (URIM) is an extremely flexible framework for rapidly integrating new sensors into the JFPASS. Each sensor system has its own proprietary protocol, which makes integration high cost and risk. The URIM communicates directly with each sensor system though a protocol module and maintains a generic data object representation for each sensor. The URIM then performs a translation of the data into a single protocol, in this case Systems Engineering and Integration Working Group (SEIWG) ICD-0100. With this common protocol the data can be provided to a data server for publishing. Also, this allows for network control and management of all sensor systems via any C2 node connected to the data server.

  12. An EMG-driven musculoskeletal model to estimate muscle forces and knee joint moments in vivo.

    Science.gov (United States)

    Lloyd, David G; Besier, Thor F

    2003-06-01

    This paper examined if an electromyography (EMG) driven musculoskeletal model of the human knee could be used to predict knee moments, calculated using inverse dynamics, across a varied range of dynamic contractile conditions. Muscle-tendon lengths and moment arms of 13 muscles crossing the knee joint were determined from joint kinematics using a three-dimensional anatomical model of the lower limb. Muscle activation was determined using a second-order discrete non-linear model using rectified and low-pass filtered EMG as input. A modified Hill-type muscle model was used to calculate individual muscle forces using activation and muscle tendon lengths as inputs. The model was calibrated to six individuals by altering a set of physiologically based parameters using mathematical optimisation to match the net flexion/extension (FE) muscle moment with those measured by inverse dynamics. The model was calibrated for each subject using 5 different tasks, including passive and active FE in an isokinetic dynamometer, running, and cutting manoeuvres recorded using three-dimensional motion analysis. Once calibrated, the model was used to predict the FE moments, estimated via inverse dynamics, from over 200 isokinetic dynamometer, running and sidestepping tasks. The inverse dynamics joint moments were predicted with an average R(2) of 0.91 and mean residual error of approximately 12 Nm. A re-calibration of only the EMG-to-activation parameters revealed FE moments prediction across weeks of similar accuracy. Changing the muscle model to one that is more physiologically correct produced better predictions. The modelling method presented represents a good way to estimate in vivo muscle forces during movement tasks.

  13. Force-velocity, force-power relationships of bilateral and unilateral leg multi-joint movements in young and elderly women.

    Science.gov (United States)

    Yamauchi, Junichiro; Mishima, Chizuko; Nakayama, Satoshi; Ishii, Naokata

    2009-09-18

    The present study investigated force-velocity and force-power relationships of bilateral and unilateral knee-hip extension movement in young and elderly women. Twelve healthy young (age, 19-31 yr) and 12 healthy elderly (age, 60-82 yr) women performed bilateral and unilateral knee-hip extension movements on the dynamometer against loads controlled by the servo system. Under the isotonic force condition, force-velocity relationships were measured. The maximum isometric force (F(max)), unloaded velocity (V(max)) and power output (P(max)) of the movements were calculated from extrapolating force-velocity and force-power relationships. F(max) and P(max) of bilateral and unilateral knee-hip extension movements were 20-30% lower in elderly than in young women. On the other hand, there were no significant differences in V(max) between young and elderly women and between bilateral and unilateral movements. Bilateral deficit was larger as the generation of force was larger in both young and elderly women. Also, bilateral deficit of F(max) and P(max) were not different between young and elderly women. The results were that lower maximum power output of bilateral and unilateral leg multi-joint movements in elderly women did not depend on the intrinsic shortening velocity of muscle action, but largely on reduction in force generating capacity. This suggests the importance of preventing a loss of force generating capacity of muscles during leg multi-joint movements in elderly women.

  14. The Application and Effect of Acupuncture and Moxibustion in Treatment of Cervical Facet Joints%中医针灸疗法在颈椎小关节错缝治疗中的应用及效果

    Institute of Scientific and Technical Information of China (English)

    王宏刚

    2015-01-01

    目的:评价中医针灸疗法在颈椎小关节错缝治疗中的效果。方法本次选取研究对象60例,均为我院2014年6~12月接受治疗的颈椎小关节错缝患者。将60例颈椎小关节错缝患者随机分为对照组(n=30例)和实验组(n=30例)。对照组给予西医治疗,包括理疗、局部制动、药物治疗、颈椎牵引。实验组在此基础上给予中医针灸治疗。比较分析实验组和对照组患者的治疗效果。患者活动能力。结果(1)实验组住院时间短于对照组,患者活动能力优于对照组,P <0.05,差异有统计学意义。(2)实验组治疗效果优于对照组,P <0.05,差异具有统计学意义。结论中医针灸治疗对于治疗颈椎小关节错缝的患者具有重要的意义。%Objective To evaluate acupuncture therapy in the treatment of Cervical Small Joint in effect. Methods The study selected 60 patients in our hospital in June 2014 to December treated cervical Small Joint patients. 60 cases of cervical Small Joint patients were randomly divided into control group (n = 30 patients) and the experimental group (n=30 patients). The control group received Western medicine treatment, including physical therapy, immobilization, drug therapy, cervical traction. Experimental group received acupuncture treatment on this basis. Comparative analysis of the experimental treatment group and the control group of patients. Patient mobility. Results (1) Experimental group than the control group, shorter hospital stay, patient activity than the control group, P<0.05, The difference was statistically significant. (2) Treatment experimental group than the control group, P <0.05, The difference was statistically significant. Conclusion Acupuncture therapy for the treatment of patients with cervical facet joint dislocation seam has important significance.

  15. Faceted Semantic Search for Personalized Social Search

    CERN Document Server

    Mas, Massimiliano Dal

    2012-01-01

    Actual social networks (like Facebook, Twitter, Linkedin, ...) need to deal with vagueness on ontological indeterminacy. In this paper is analyzed the prototyping of a faceted semantic search for personalized social search using the "joint meaning" in a community environment. User researches in a "collaborative" environment defined by folksonomies can be supported by the most common features on the faceted semantic search. A solution for the context-aware personalized search is based on "joint meaning" understood as a joint construal of the creators of the contents and the user of the contents using the faced taxonomy with the Semantic Web. A proof-of concept prototype shows how the proposed methodological approach can also be applied to existing presentation components, built with different languages and/or component technologies.

  16. 综合手法治疗胸椎小关节紊乱520例临床分析%Clinical analysis on 520 cases of thoracic facet joint disorder treated with comprehensive manipulation

    Institute of Scientific and Technical Information of China (English)

    姜山

    2016-01-01

    ObjectiveTo study the effect of manipulative reduction in the treatment of thoracic facet joint disorders.Methods According to the position of the small joint disorder of thoracic vertebrae, 5 different methods were used to observe the curative effect. Results In this group, 520 cases, 1 cases were cured, 112 cases were cured, 98 cases were markedly effective, 46 cases were improved, 0 cases were ineffective, the cure rate was 72.3%, the total effective rate was 100%.Conclusion The treatment of 520 cases of this group by the above methods, the curative effect is remarkable, the method is simple and easy, and it is worth to be popularized and applied.%目的:研究胸椎小关节紊乱手法复位治疗效果。方法:根据患者胸椎小关节紊乱的位置不同采用5种方法进行治疗观察其疗效。结果:本组520例,1次治愈264例,2~6次治愈112例,显效98例,好转46例,无效0例,治愈率72.3%,总有效率100%。结论:通过上述手法对本组520例患者的治疗,疗效显著,其方法简单易行,值得临床推广运用。

  17. Steeper posterior tibial slope markedly increases ACL force in both active gait and passive knee joint under compression.

    Science.gov (United States)

    Marouane, H; Shirazi-Adl, A; Adouni, M; Hashemi, J

    2014-04-11

    The role of the posterior tibial slope (PTS) in anterior cruciate ligament (ACL) risk of injury has been supported by many imaging studies but refuted by some in vitro works. The current investigation was carried out to compute the effect of ±5(o) change in PTS on knee joint biomechanics in general and ACL force/strain in particular. Two validated finite element (FE) models of the knee joint were employed; one active lower extremity musculoskeletal model including a complex FE model of the knee joint driven by in vivo kinematics/kinetics collected in gait of asymptomatic subjects, and the other its isolated unconstrained passive tibiofemoral (TF) joint considered under 1400 N compression at four different knee flexion angles (0°-45°). In the TF model, the compression force was applied at the joint mechanical balance point causing no rotations in sagittal and frontal planes. Changes in PTS moderately affected muscle forces and joint contact forces at mid-stance period. Both active (at mid-stance) and passive (at all flexion angles) models showed a substantial increase in the anterior tibial translation and ACL force as PTS increased with reverse trends as PTS decreased. In the active model of gait at mid-stance, ACL force increased by 75% (from 181 N to 317 N) in steeper PTS but decreased by 44% (to 102 N) in flatter PTS. The posterolateral bundle of ACL carried the load at smaller flexion angles with a shift to its anteromedial bundle as flexion increased. In accordance with earlier imaging studies, greater PTS is a major risk factor for ACL rupture especially in activities involving large compression forces. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Joint Task Force on Undergraduate Physics Programs (J-TUPP): Overview and Major Findings

    Science.gov (United States)

    Heron, Paula

    2016-03-01

    The Joint Task Force on Undergraduate Physics Programs (JTUPP) was formed in response to growing awareness in the physics community that physics majors pursue a wide range of careers after graduation, with very few ending up in academia. The task force is charged with identifying the skills and knowledge that undergraduate physics degree holders should possess to be well prepared for a diverse set of careers, and providing guidance for physicists considering revising the undergraduate curriculum to improve the education of a diverse student population. Task force members represent large and small universities, professional societies, and industry, and have expertise in a broad range of areas including entrepreneurship, physics education research and systemic change in education. We reviewed employment data, surveys of employers, and reports generated by other disciplines. We also met with physicists in selected industries to get their views on the strengths and weaknesses of physics graduates, commissioned a series of interviews with recent physics graduates employed in the private sector, and identified exemplary programs that ensure that all of their students are well prepared to pursue a wide range of career paths. The findings and recommendations will be summarized.

  19. Multiwalled nanotube faceting unravelled

    Science.gov (United States)

    Leven, Itai; Guerra, Roberto; Vanossi, Andrea; Tosatti, Erio; Hod, Oded

    2016-12-01

    Nanotubes show great promise for miniaturizing advanced technologies. Their exceptional physical properties are intimately related to their morphological and crystal structure. Circumferential faceting of multiwalled nanotubes reinforces their mechanical strength and alters their tribological and electronic properties. Here, the nature of this important phenomenon is fully rationalized in terms of interlayer registry patterns. Regardless of the nanotube identity (that is, diameter, chirality, chemical composition), faceting requires the matching of the chiral angles of adjacent layers. Above a critical diameter that corresponds well with experimental results, achiral multiwalled nanotubes display evenly spaced extended axial facets whose number equals the interlayer difference in circumferential unit cells. Elongated helical facets, commonly observed in experiment, appear in nanotubes that exhibit small interlayer chiral angle mismatch. When the wall chiralities are uncorrelated, faceting is suppressed and outer layer corrugation, which is induced by the Moiré superlattice, is obtained in agreement with experiments. Finally, we offer an explanation for the higher incidence of faceting in multiwalled boron nitride nanotubes with respect to their carbon-based counterparts.

  20. The acute effects of static stretching on peak force, peak rate of force development and muscle activity during single- and multiple-joint actions in older women.

    Science.gov (United States)

    Gonçalves, Raquel; Gurjão, André Luiz Demantova; Jambassi Filho, José Claudio; Farinatti, Paulo De Tarso Veras; Gobbi, Lilian Teresa Bucken; Gobbi, Sebastião

    2013-01-01

    The present study investigated the acute effects of static stretching on peak force, peak rate of force development and integrated electromyography (iEMG) in 27 older women (65 ± 4 years; 69 ± 9 kg; 157 ± 1 cm; 28 ± 4 kg · m(-2)). The participants were tested during two exercises (leg press and knee extension) after two conditions: stretching and control. The data were collected on four days (counterbalanced with a 24-hour rest period). In the stretching condition, the quadriceps muscle was stretched (knee flexion) for three sets of 30 s with 30 s rest intervals. No significant difference was detected for peak force and peak rate of force development during the single- and multiple-joint exercises, regardless of the following interactions: condition (stretching and control) vs. time (pre x post x 10 x 20 x 30 minutes post; P > 0.05) and exercise vs. time (P > 0.05). Additionally, no significant interaction was found for the iEMG activity (condition vs. time; P > 0.05) in the single- and multiple-joint exercises. In conclusion, a small amount of stretching of an agonist muscle (quadriceps) did not affect the peak force, peak rate of force development and EMG activity in older women during single- and multiple-joint exercises.

  1. [The effect of the motion of forefoot joint at the force exerted upon the floor during walking exercise].

    Science.gov (United States)

    Maeda, A; Nishizono, H; Ebashi, H; Shibayama, H

    1993-11-01

    In walking exercise the human body is exposed to external forces. Some of them are produced by constraints such as surface, shoes or opponent. In kick action of walking, the ground reaction force (GRF) is the most important external force. The magnitude of the GRF, its direction, and point of application have an influence on the load on the human body. The purpose of this study is to clarify the role of forefoot joint (artt. metatarsophalangeae) at the force exerted upon the floor during kick action of walking. The device used in this study to analyze the GRF and its three components consists of Kistler's force platform. Output from force transducer was collected online with a TEAC data recorder and MEM-4101 minicomputer. The impact force measurements were taken from the anterior-posterior force time curves at the take-off for 1 subject walking 10 trials at 2 m/sec with 2 different pairs of shoes (Shoes 1: thin sole of 4mm, and Shoes 2: thick sole of 40mm) and without shoes. High speed (200f/sec) cinematography was also used to analyze the angular displacement of forefoot joint at the take-off of walking exercise. The force acting at the forefoot joint may produce the anterior-posterior force of the GRF which is defined as the propelling power acting on the human body during walking exercise. The result showed that the impact force peak occurred 40-60 msec before take-off and the propelling part of kick action accounted for only about 6% of the external force.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. Bite force in the extant coelacanth Latimeria: the role of the intracranial joint and the basicranial muscle.

    Science.gov (United States)

    Dutel, Hugo; Herbin, Marc; Clément, Gaël; Herrel, Anthony

    2015-05-01

    The terrestrialization process involved dramatic changes in the cranial anatomy of vertebrates. The braincase, which was initially divided into two portions by the intracranial joint in sarcopterygian fishes, became consolidated into a single unit in tetrapods and lungfishes [1-3]. The coelacanth Latimeria is the only extant vertebrate that retains an intracranial joint, which is associated with a unique paired muscle: the basicranial muscle. The intracranial joint has long been thought to be involved in suction feeding by allowing an extensive elevation of the anterior portion of the skull, followed by its rapid depression driven by the basicranial muscle [4-7]. However, we recently challenged this hypothesis [8, 9], and the role of the basicranial muscle with respect to the intracranial joint thus remains unclear. Using 3D biomechanical modeling, we show here that the basicranial muscle and the intracranial joint are involved in biting force generation. By flexing the anterior portion of the skull at the level of the intracranial joint, the basicranial muscle increases the overall bite force. This likely allows Latimeria to feed on a broad range of preys [10, 11] and coelacanths to colonize a wide range of environments during their evolution [4]. The variation in the morphology of the intracranial joint observed in Devonian lobe-finned fishes would have impacted to various degrees their biting performance and might have permitted feeding specializations despite the stability in their lower jaw morphology [12]. VIDEO ABSTRACT.

  3. The effects of mechanical forces on bones and joints. Experimental study on the rat tail.

    Science.gov (United States)

    Pazzaglia, U E; Andrini, L; Di Nucci, A

    1997-11-01

    We have used an experimental model employing the bent tail of rats to investigate the effects of mechanical forces on bones and joints. Mechanical strain could be applied to the bones and joints of the tail without direct surgical exposure or the application of pins and wires. The intervertebral disc showed stretched annular lamellae on the convex side, while the annulus fibrosus on the concave side was pinched between the inner corners of the vertebral epiphysis. In young rats with an active growth plate, a transverse fissure appeared at the level of the hypertrophic cell layer or the primary metaphyseal trabecular zone. Metaphyseal and epiphyseal trabeculae on the compressed side were thicker and more dense than those of the distracted part of the vertebra. In growing animals, morphometric analysis of hemiepiphyseal and hemimetaphyseal areas, and the corresponding trabecular bone density, showed significant differences between the compressed and distracted sides. No differences were observed in adult rats. We found no significant differences in osteoclast number between compressed and distracted sides in either age group. Our results provide quantitative evidence of the working of 'Wolff's law'. The differences in trabecular density are examples of remodelling by osteoclasts and osteoblasts; our finding of no significant difference in osteoclast numbers between the hemiepiphyses in the experimental and control groups suggests that the response of living bone to altered strain is mediated by osteoblasts.

  4. Reductions in knee joint forces with weight loss are attenuated by gait adaptations in class III obesity.

    Science.gov (United States)

    DeVita, Paul; Rider, Patrick; Hortobágyi, Tibor

    2016-03-01

    A consensus exists that high knee joint forces are a precursor to knee osteoarthritis and weight loss reduces these forces. Because large weight loss also leads to increased step length and walking velocity, knee contact forces may be reduced less than predicted by the magnitude of weight loss. The purpose was to determine the effects of weight loss on knee muscle and joint loads during walking in Class III obese adults. We determined through motion capture, force platform measures and biomechanical modeling the effects of weight loss produced by gastric bypass surgery over one year on knee muscle and joint loads during walking at a standard, controlled velocity and at self-selected walking velocities. Weight loss equaling 412 N or 34% of initial body weight reduced maximum knee compressive force by 824 N or 67% of initial body weight when walking at the controlled velocity. These changes represent a 2:1 reduction in knee force relative to weight loss when walking velocity is constrained to the baseline value. However, behavioral adaptations including increased stride length and walking velocity in the self-selected velocity condition attenuated this effect by ∼50% leading to a 392 N or 32% initial body weight reduction in compressive force in the knee joint. Thus, unconstrained walking elicited approximately 1:1 ratio of reduction in knee force relative to weight loss and is more indicative of walking behavior than the standard velocity condition. In conclusion, massive weight loss produces dramatic reductions in knee forces during walking but when patients stride out and walk faster, these favorable reductions become substantially attenuated.

  5. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    Science.gov (United States)

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-01-01

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications. PMID:27529244

  6. Prediction of hip joint load and translation using musculoskeletal modelling with force-dependent kinematics and experimental validation.

    Science.gov (United States)

    Zhang, Xuan; Chen, Zhenxian; Wang, Ling; Yang, Wenjian; Li, Dichen; Jin, Zhongmin

    2015-07-01

    Musculoskeletal lower limb models are widely used to predict the resultant contact force in the hip joint as a non-invasive alternative to instrumented implants. Previous musculoskeletal models based on rigid body assumptions treated the hip joint as an ideal sphere with only three rotational degrees of freedom. An musculoskeletal model that considered force-dependent kinematics with three additional translational degrees of freedom was developed and validated in this study by comparing it with a previous experimental measurement. A 32-mm femoral head against a polyethylene cup was considered in the musculoskeletal model for calculating the contact forces. The changes in the main modelling parameters were found to have little influence on the hip joint forces (relative deviation of peak value kinematics approach underestimated the maximum hip contact force by a mean value of 6.68 ± 1.75% BW compared with the experimental measurements. The predicted maximum translations of the hip joint centres were 0.125 ± 0.03 mm in level walking and 0.123 ± 0.005 mm in climbing stairs.

  7. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor

    Directory of Open Access Journals (Sweden)

    Yanzhi Zhao

    2016-08-01

    Full Text Available Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  8. Mathematical Model and Calibration Experiment of a Large Measurement Range Flexible Joints 6-UPUR Six-Axis Force Sensor.

    Science.gov (United States)

    Zhao, Yanzhi; Zhang, Caifeng; Zhang, Dan; Shi, Zhongpan; Zhao, Tieshi

    2016-08-11

    Nowadays improving the accuracy and enlarging the measuring range of six-axis force sensors for wider applications in aircraft landing, rocket thrust, and spacecraft docking testing experiments has become an urgent objective. However, it is still difficult to achieve high accuracy and large measuring range with traditional parallel six-axis force sensors due to the influence of the gap and friction of the joints. Therefore, to overcome the mentioned limitations, this paper proposed a 6-Universal-Prismatic-Universal-Revolute (UPUR) joints parallel mechanism with flexible joints to develop a large measurement range six-axis force sensor. The structural characteristics of the sensor are analyzed in comparison with traditional parallel sensor based on the Stewart platform. The force transfer relation of the sensor is deduced, and the force Jacobian matrix is obtained using screw theory in two cases of the ideal state and the state of flexibility of each flexible joint is considered. The prototype and loading calibration system are designed and developed. The K value method and least squares method are used to process experimental data, and in errors of kind Ι and kind II linearity are obtained. The experimental results show that the calibration error of the K value method is more than 13.4%, and the calibration error of the least squares method is 2.67%. The experimental results prove the feasibility of the sensor and the correctness of the theoretical analysis which are expected to be adopted in practical applications.

  9. Verification of joint input-state estimation for force identification by means of in situ measurements on a footbridge

    Science.gov (United States)

    Maes, K.; Nimmen, K. Van; Lourens, E.; Rezayat, A.; Guillaume, P.; Roeck, G. De; Lombaert, G.

    2016-06-01

    This paper presents a verification of a joint input-state estimation algorithm using data obtained from in situ experiments on a footbridge. The estimation of the input and the system states is performed in a minimum-variance unbiased way, based on a limited number of response measurements and a system model. A dynamic model of the footbridge is obtained using a detailed finite element model that is updated using a set of experimental modal characteristics. The joint input-state estimation algorithm is used for the identification of two impact, harmonic, and swept sine forces applied to the bridge deck. In addition to these forces, unknown stochastic forces, such as wind loads, are acting on the structure. These forces, as well as measurement errors, give rise to uncertainty in the estimated forces and system states. Quantification of the uncertainty requires determination of the power spectral density of the unknown stochastic excitation, which is identified from the structural response under ambient loading. The verification involves comparing the estimated forces with the actual, measured forces. Although a good overall agreement is obtained between the estimated and measured forces, modeling errors prohibit a proper distinction between multiple forces applied to the structure for the case of harmonic and swept sine excitation.

  10. Moments About Body Centered Coordinate Axes At Limb Joints From Force Plate And Biplane Photography Measurements

    Science.gov (United States)

    Balakrishnan, S.; Thornton-Trump, A. B.; Brodland, G. W.

    1983-07-01

    Traditional locomotion analysis considers motion in a translating coordinate frame and the analysis is performed primarily in the sagittal plane. The results of several studies in the present work have shown that the aspect of symmetry is rarely present in pathological gait. Loss of function in one plane of movement gives rise to larger motions in other planes. This brings into focus the necessity for three dimensional measurement for adequately representing pathological gait. Description of quantities associated with gait in the appropriate moving frame of each segment would be closer to joint angulation of limb segments. Although this description has been attempted by a few researchers, the assumption of small angle theory and vectorial addition of rotation angles commonly employed for defining the rotation matrices is not applicable to pathological gait. The present work illustrates the use of biplane photography for displacement measurement in human movement. Transformations based on Eulerian angle rotations are derived based on biplane measurements. From the three dimensional ground reaction forces measured by a force plate, moments about the moving upper body coordinate axes are computed through a three dimensional mathematical model.

  11. The effect of perturbing body segment parameters on calculated joint moments and muscle forces during gait.

    Science.gov (United States)

    Wesseling, Mariska; de Groote, Friedl; Jonkers, Ilse

    2014-01-22

    This study examined the effect of body segment parameter (BSP) perturbations on joint moments calculated using an inverse dynamics procedure and muscle forces calculated using computed muscle control (CMC) during gait. BSP (i.e. segment mass, center of mass location (com) and inertia tensor) of the left thigh, shank and foot of a scaled musculoskeletal model were perturbed. These perturbations started from their nominal value and were adjusted to ±40% in steps of 10%, for both individual as well as combined perturbations in BSP. For all perturbations, an inverse dynamics procedure calculated the ankle, knee and hip moments based on an identical inverse kinematics solution. Furthermore, the effect of applying a residual reduction algorithm (RRA) was investigated. Muscle excitations and resulting muscle forces were calculated using CMC. The results show only a limited effect of an individual parameter perturbation on the calculated moments, where the largest effect is found when perturbing the shank com (MS(com,shank), the ratio of absolute difference in torque and relative parameter perturbation, is maximally -7.81 N m for hip flexion moment). The additional influence of perturbing two parameters simultaneously is small (MS(mass+com,thigh) is maximally 15.2 N m for hip flexion moment). RRA made small changes to the model to increase the dynamic consistency of the simulation (after RRA MS(com,shank) is maximally 5.01 N m). CMC results show large differences in muscle forces when BSP are perturbed. These result from the underlying forward integration of the dynamic equations.

  12. Trans-facet joints approach to treat thoracic degenerative diseases with anterior compression%经关节突入路治疗前方骨性压迫型胸椎退行性疾患

    Institute of Scientific and Technical Information of China (English)

    马学晓; 陈伯华; 张岩; 张国庆; 胡有谷

    2010-01-01

    Objective To investigate the clinical outcomes of trans-facet joints approach to treat thoracic degenerative disease with anterior compression.Methods From January 2003 to December 2009,22 patients with thoracic myelopathy caused by anterior compression were studied retrospectively.The patients included 16 males and 6 females,aged from 36 to 72 years(average 54.2 years).There were thoracic ossification of posterior longitudinal ligament(OPLL)in 11 cases,thoracic disc protrusion with ossification in 8 cases,thoracic vertebra posterior osteophytes in 2 cases,ankylosing spondylitis with thoracic pseudoarthrosis in 1 cases.Preoperative Japanese Orthopaedic Association(JOA)score was 5.2(range,2-9).The characteristic of thoracic degeneration was analyzed by CT and MRI examination.Posterior decompressive laminectomies were performed by the technique of "cap uncovering".The facet joints were removed bilaterally.Anterior ossified compressions were cut via posterior-lateral approach,and then intervertebral bone graft and bilateral pedicle screws were implanted.Results All patients were followed up for 8 to 38 months.According to the revised Epstein standard,there were excellent in 7 patients,good in 9,fair in 4,and poor in 2.The total effective rate was 90.9%(20/22).The excellent and good rate was 72.7%(16/22).The mean postoperative JOA score was 8.7(range,2-11).Surgical complications included dural laceration in 1 patient,pleura injury in 1 patient,epidural hematoma in 2 patients.There were no cases of spinal instability or deep infection.Conclusion The anterior compression can be solved completely via trans-facet joints approach in thoracic degenerative disease patients.%目的 探讨经关节突入路治疗前方骨性致压型胸椎退行性疾患的手术方法和治疗效果.方法 2003年1月至2009年12月,收治前方骨性致压型胸椎退行性疾患患者22例,男16例,女6例;年龄36~72岁,平均54.2岁;胸椎后纵韧带骨化11

  13. Amsterdam Oxford Joint Rescue Forces: Team description paper: Virtual Robot competition: Rescue Simulation League: RoboCup 2009

    NARCIS (Netherlands)

    A. Visser; G.E. Maillette de Buij Wenniger; H. Nijhuis; F. Alnajar; B. Huijten; M. van der Velden; W. Josemans; B. Terwijn; C. Walraven; Q. Nguyen; R. Sobolewski; H. Flynn; M. Jankowska; J. de Hoog

    2009-01-01

    With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distributing exploration locations over the team. To navigate autonomously towards those locations, the robots gradually aggregate their experience in a traversa

  14. A neural network approach for determining gait modifications to reduce the contact force in knee joint implant.

    Science.gov (United States)

    Ardestani, Marzieh Mostafavizadeh; Chen, Zhenxian; Wang, Ling; Lian, Qin; Liu, Yaxiong; He, Jiankang; Li, Dichen; Jin, Zhongmin

    2014-10-01

    There is a growing interest in non-surgical gait rehabilitation treatments to reduce the loading in the knee joint. In particular, synergetic kinematic changes required for joint offloading should be determined individually for each subject. Previous studies for gait rehabilitation designs are typically relied on a "trial-and-error" approach, using multi-body dynamic (MBD) analysis. However MBD is fairly time demanding which prevents it to be used iteratively for each subject. This study employed an artificial neural network to develop a cost-effective computational framework for designing gait rehabilitation patterns. A feed forward artificial neural network (FFANN) was trained based on a number of experimental gait trials obtained from literature. The trained network was then hired to calculate the appropriate kinematic waveforms (output) needed to achieve desired knee joint loading patterns (input). An auxiliary neural network was also developed to update the ground reaction force and moment profiles with respect to the predicted kinematic waveforms. The feasibility and efficiency of the predicted kinematic patterns were then evaluated through MBD analysis. Results showed that FFANN-based predicted kinematics could effectively decrease the total knee joint reaction forces. Peak values of the resultant knee joint forces, with respect to the bodyweight (BW), were reduced by 20% BW and 25% BW in the midstance and the terminal stance phases. Impulse values of the knee joint loading patterns were also decreased by 17% BW*s and 24%BW*s in the corresponding phases. The FFANN-based framework suggested a cost-effective forward solution which directly calculated the kinematic variations needed to implement a given desired knee joint loading pattern. It is therefore expected that this approach provides potential advantages and further insights into knee rehabilitation designs.

  15. Facets of Subjectification

    Science.gov (United States)

    Visconti, Jacqueline

    2013-01-01

    Subjectification, as the diachronic facet of subjectivity, has raised in the last two decades a number of interesting questions in grammaticalization and semantic change theory. In this paper I shall reflect on the nature and construal of subjectification, focusing on the question, formulated by Traugott (2010a, p. 58), "whether it is possible to…

  16. A 3D lower limb musculoskeletal model for simultaneous estimation of musculo-tendon, joint contact, ligament and bone forces during gait.

    Science.gov (United States)

    Moissenet, Florent; Chèze, Laurence; Dumas, Raphaël

    2014-01-03

    Musculo-tendon forces and joint reaction forces are typically estimated using a two-step method, computing first the musculo-tendon forces by a static optimization procedure and then deducing the joint reaction forces from the force equilibrium. However, this method does not allow studying the interactions between musculo-tendon forces and joint reaction forces in establishing this equilibrium and the joint reaction forces are usually overestimated. This study introduces a new 3D lower limb musculoskeletal model based on a one-step static optimization procedure allowing simultaneous musculo-tendon, joint contact, ligament and bone forces estimation during gait. It is postulated that this approach, by giving access to the forces transmitted by these musculoskeletal structures at hip, tibiofemoral, patellofemoral and ankle joints, modeled using anatomically consistent kinematic models, should ease the validation of the model using joint contact forces measured with instrumented prostheses. A blinded validation based on four datasets was made under two different minimization conditions (i.e., C1 - only musculo-tendon forces are minimized, and C2 - musculo-tendon, joint contact, ligament and bone forces are minimized while focusing more specifically on tibiofemoral joint contacts). The results show that the model is able to estimate in most cases the correct timing of musculo-tendon forces during normal gait (i.e., the mean coefficient of active/inactive state concordance between estimated musculo-tendon force and measured EMG envelopes was C1: 65.87% and C2: 60.46%). The results also showed that the model is potentially able to well estimate joint contact, ligament and bone forces and more specifically medial (i.e., the mean RMSE between estimated joint contact force and in vivo measurement was C1: 1.14BW and C2: 0.39BW) and lateral (i.e., C1: 0.65BW and C2: 0.28BW) tibiofemoral contact forces during normal gait. However, the results remain highly influenced by the

  17. Infliximab partially alleviates the bite force reduction in a mouse model of temporomandibular joint pain.

    Science.gov (United States)

    Kim, Sang-Hyon; Son, Chang-Nam; Lee, Hyo-Jung; Cho, Ho-Chan; Jung, Sung-Won; Hur, Ji An; Baek, Won-Ki; Jung, Hye Ra; Hong, Ji Hee

    2015-05-01

    Temporomandibular joint (TMJ) disorder is clinically important because of its prevalence, chronicity, and therapy-refractoriness of the pain. In this study, we investigated the effect of infliximab in a mouse model of TMJ pain using a specially-engineered transducer for evaluating the changes in bite force (BF). The mice were randomly divided into three groups (7 mice per group): the control group, the complete Freund's adjuvant (CFA) group, and the infliximab group. BF was measured at day 0 (baseline BF). After measuring the baseline BF, CFA or incomplete Freund's adjuvant was injected into both TMJs and then the changes in BF were measured at days 1, 3, 5, 7, 9, and 13 after the TMJ injection. For measuring the BF, we used a custom-built BF transducer. Control, CFA, and infliximab groups showed similar baseline BF at day 0. From day 1, a significant reduction in BF was observed in the CFA group, and this reduction in BF was statistically significant compared to that in the control group (P infliximab group also, the reduction in BF was observed on day 1, and this reduction was maintained until day 7. However, the degree of reduction in BF was less remarkable compared to that in the CFA group. The reduction in BF caused by injection of CFA into the TMJ could be partially alleviated by the injection of anti-tumor necrosis factor alpha, infliximab.

  18. Joint positioning sense, perceived force level and two-point discrimination tests of young and active elderly adults

    Directory of Open Access Journals (Sweden)

    Priscila G. Franco

    2015-08-01

    Full Text Available Background: Changes in the proprioceptive system are associated with aging. Proprioception is important to maintaining and/or recovering balance and to reducing the risk of falls.Objective:To compare the performance of young and active elderly adults in three proprioceptive tests.Method:Twenty-one active elderly participants (66.9±5.5 years and 21 healthy young participants (24.6±3.9 years were evaluated in the following tests: perception of position of the ankle and hip joints, perceived force level of the ankle joint, and two-point discrimination of the sole of the foot.Results:No differences (p>0.05 were found between groups for the joint position and perceived force level. On the other hand, the elderly participants showed lower sensitivity in the two-point discrimination (higher threshold when compared to the young participants (p < 0.01.Conclusion:Except for the cutaneous plantar sensitivity, the active elderly participants had maintained proprioception. Their physical activity status may explain similarities between groups for the joint position sense and perceived force level, however it may not be sufficient to prevent sensory degeneration with aging.

  19. Effects of simulated genu valgum and genu varum on ground reaction forces and subtalar joint function during gait.

    Science.gov (United States)

    Van Gheluwe, Bart; Kirby, Kevin A; Hagman, Friso

    2005-01-01

    The mechanical effects of genu valgum and varum deformities on the subtalar joint were investigated. First, a theoretical model of the forces within the foot and lower extremity during relaxed bipedal stance was developed predicting the rotational effect on the subtalar joint due to genu valgum and varum deformities. Second, a kinetic gait study was performed involving 15 subjects who walked with simulated genu valgum and genu varum over a force plate and a plantar pressure mat to determine the changes in the ground reaction force vector within the frontal plane and the changes in the center-of-pressure location on the plantar foot. These results predicted that a genu varum deformity would tend to cause a subtalar pronation moment to increase or a supination moment to decrease during the contact and propulsion phases of walking. With genu valgum, it was determined that during the contact phase a subtalar pronation moment would increase, whereas in the early propulsive phase, a subtalar supination moment would increase or a pronation moment would decrease. However, the current inability to track the spatial position of the subtalar joint axis makes it difficult to determine the absolute direction and magnitudes of the subtalar joint moments.

  20. Subject-specific hip geometry and hip joint centre location affects calculated contact forces at the hip during gait.

    Science.gov (United States)

    Lenaerts, G; Bartels, W; Gelaude, F; Mulier, M; Spaepen, A; Van der Perre, G; Jonkers, I

    2009-06-19

    Hip loading affects the development of hip osteoarthritis, bone remodelling and osseointegration of implants. In this study, we analyzed the effect of subject-specific modelling of hip geometry and hip joint centre (HJC) location on the quantification of hip joint moments, muscle moments and hip contact forces during gait, using musculoskeletal modelling, inverse dynamic analysis and static optimization. For 10 subjects, hip joint moments, muscle moments and hip loading in terms of magnitude and orientation were quantified using three different model types, each including a different amount of subject-specific detail: (1) a generic scaled musculoskeletal model, (2) a generic scaled musculoskeletal model with subject-specific hip geometry (femoral anteversion, neck-length and neck-shaft angle) and (3) a generic scaled musculoskeletal model with subject-specific hip geometry including HJC location. Subject-specific geometry and HJC location were derived from CT. Significant differences were found between the three model types in HJC location, hip flexion-extension moment and inclination angle of the total contact force in the frontal plane. No model agreement was found between the three model types for the calculation of contact forces in terms of magnitude and orientations, and muscle moments. Therefore, we suggest that personalized models with individualized hip joint geometry and HJC location should be used for the quantification of hip loading. For biomechanical analyses aiming to understand modified hip joint loading, and planning hip surgery in patients with osteoarthritis, the amount of subject-specific detail, related to bone geometry and joint centre location in the musculoskeletal models used, needs to be considered.

  1. Joint-bounded crescentic scars formed by subglacial clast-bed contact forces: Implications for bedrock failure beneath glaciers

    Science.gov (United States)

    Krabbendam, M.; Bradwell, T.; Everest, J. D.; Eyles, N.

    2017-08-01

    Glaciers and ice sheets are important agents of bedrock erosion, yet the precise processes of bedrock failure beneath glacier ice are incompletely known. Subglacially formed erosional crescentic markings (crescentic gouges, lunate fractures) on bedrock surfaces occur locally in glaciated areas and comprise a conchoidal fracture dipping down-ice and a steep fracture that faces up-ice. Here we report morphologically distinct crescentic scars that are closely associated with preexisting joints, termed here joint-bounded crescentic scars. These hitherto unreported features are ca. 50-200 mm deep and involve considerably more rock removal than previously described crescentic markings. The joint-bounded crescentic scars were found on abraded rhyolite surfaces recently exposed (ice produces a continuously migrating clast-bed contact force as it is dragged over the hard (bedrock) bed. As the ice-embedded boulder approaches a preexisting joint in the bedrock, stress concentrations build up in the bed that exceed the intact rock strength, resulting in conchoidal fracturing and detachment of a crescentic wedge-shaped rock fragment. Subsequent removal of the rock fragment probably involves further fracturing or crushing (comminution) under high contact forces. Formation of joint-bounded crescentic scars is favoured by large boulders at the base of the ice, high basal melting rates, and the presence of preexisting subvertical joints in the bedrock bed. We infer that the relative scarcity of crescentic markings in general on deglaciated surfaces shows that fracturing of intact bedrock below ice is difficult, but that preexisting weaknesses such as joints greatly facilitate rock failure. This implies that models of glacial erosion need to take fracture patterns of bedrock into account.

  2. Effect of Lanthanum on Driving Force for Cu6Sn5 Growth and Improvement of Solder Joint Reliability

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By means of adding low content of rare earth element La into Sn60-Pb40 solder alloy, the growth of Cu6Sn5 intermetallic compound at the interface of solder joint is hindered, and the thermal fatigue life of solder joint is increased by 2 times. The results of thermodynamic calculation based on diffusion kinetics show that, the driving force for Cu6Sn5 growth is lowered by adding small content of La in Sn60-Pb40 solder alloy. Meanwhile, there is an effective local mole fraction range of La, in which, 0.18% is the limited value and 0.08% is the best value.

  3. EFFECTS OF NOVEL ANGLED CERVICAL DISC REPLACEMENT ON FACET JOINT STRESS%角度人工颈椎间盘置换对关节突应力的影响

    Institute of Scientific and Technical Information of China (English)

    柏传毅; 张维杰; 凌伟; 田振兴; 党晓谦; 王坤正

    2012-01-01

    Objective To analyze the biomechanical changes of the adjacent cervical facet joints when the angled 'cervical prosthesis is replaced. Methods A total of 400 northwestern people were involved, with an age of 40 years or older. The cervical vertebra lateral X-ray films were taken, and the cervical angles were measured by professional computer aided design software, then the cervical intervertebral disc prosthesis with 10° angle was designed. The finite element models of G, 5 and C4-6 segments with intact cervical discs were developed; the C*, 5 disc was replaced by the cervical prosthesis with 0° and 10° angle respectively; and then all models were subjected to axial loading, flexion/extension, lateral bending, and torsion loading conditions; the stress effects on adjacent facet joints after replacement were observed by comparing with that of the intact model. Results The cervical angles were (9.97 ± 3.64)° in C3,4, (9.95 + 4.34)° in G, 5) (8.59 ± 3.75)° in C5,6, and (8.49 ± 3.39)° in C6,7, showing no significant difference between C3,4 and C4,5, Cs, 6 and C6,7 (P > 0.05) and showing significant differences between the other cervical angles (P < 0.05). When C4,5 model was axially loaded, no significant difference in equivalent shearing stress were observed in intact, 0°, and 10° groups; at flexion/extension loading, the stress was biggest in intact group, and was smallest in 10° group; at lateral bending, the stress got the high rank in intact group, and was minimum in 10° group; at torsion loading, the stress state of 10° group approached to the intact one condition. When C4-6 model was loaded, the facet joint stress of the replaced segment (C4,5) decreased significantly at axial loading, flexion/extension, and lateral bending; while no obvious decrease was observed at torsion loading; the stress of the adjacent inferior disc (Cs. 6) decreased significantly at axial loading and lateral bending condition, while less decrease was observed at torsion

  4. Quantification of the role of tibial posterior slope in knee joint mechanics and ACL force in simulated gait.

    Science.gov (United States)

    Marouane, H; Shirazi-Adl, A; Hashemi, J

    2015-07-16

    The anterior cruciate ligament (ACL) rupture is a common knee joint injury with higher prevalence in female athletes. In search of contributing mechanisms, clinical imaging studies of ACL-injured individuals versus controls have found greater medial-lateral posterior tibial slope (PTS) in injured population irrespective of the sex and in females compared to males, with stronger evidence on the lateral plateau slope. To quantify these effects, we use a lower extremity musculoskeletal model including a detailed finite element (FE) model of the knee joint to compute the role of changes in medial and/or lateral PTS by ±5° and ±10° on knee joint biomechanics, in general, and ACL force, in particular, throughout the stance phase of gait. The model is driven by reported kinematics/kinetics of gait in asymptomatic subjects. Our predictions showed, at all stance periods, a substantial increase in the anterior tibial translation (ATT) and ACL force as PTS increased with reverse trends as PTS decreased. At mid-stance, for example, ACL force increased from 181 N to 317 N and 460 N as PTS increased by 5° and 10°, respectively, while dropped to 102 N and 0 N as PTS changed by -5° and -10°, respectively. These effects are caused primarily by change in PTS at the tibial plateau that carries a larger portion of joint contact force. Steeper PTS is a major risk factor, especially under activities with large compression, in markedly increasing ACL force and its vulnerability to injury. Rehabilitation and ACL injury prevention programs could benefit from these findings. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Short-term outcome of fluoroscopic-guided steroid injection therapy of lumber facet cyst-induced radicular pain

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Mi Ri; Kwon, Jong Won; Lee, Jong Seo; Kim, Eu Sang [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2015-04-15

    To determine the short-term effect of fluoroscopic-guided steroid injection therapy of lumbar facet cyst-induced radicular pain. Seventeen patients with radiculopathy due to lumbar synovial cysts, who were treated with fluoroscopically guided injection, were retrospectively evaluated. All plain radiographic images and MR images before the therapy were reviewed. Five patients underwent only the facet joint injection, whereas twelve patients underwent the facet joint injection with perineural injection therapy. The clinical course of pain was evaluated on the first follow-up after therapy. Effective pain relief was achieved in 11 (64.7%) of the 17 patients. Among 12 patients who underwent facet joint injection with perineural injection, 9 patients (75%) had an effective pain relief. Of 5 patients, 2 (40%) patients only took the facet joint injection and had an effective pain relief. Fluoroscopic-guided steroid injection therapy shows a good short-term effect in patients with symptomatic lumbar facet joint synovial cysts.

  6. Prediction of medial and lateral contact force of the knee joint during normal and turning gait after total knee replacement.

    Science.gov (United States)

    Purevsuren, Tserenchimed; Dorj, Ariunzaya; Kim, Kyungsoo; Kim, Yoon Hyuk

    2016-04-01

    The computational modeling approach has commonly been used to predict knee joint contact forces, muscle forces, and ligament loads during activities of daily living. Knowledge of these forces has several potential applications, for example, within design of equipment to protect the knee joint from injury and to plan adequate rehabilitation protocols, although clinical applications of computational models are still evolving and one of the limiting factors is model validation. The objective of this study was to extend previous modeling technique and to improve the validity of the model prediction using publicly available data set of the fifth "Grand Challenge Competition to Predict In Vivo Knee Loads." A two-stage modeling approach, which combines conventional inverse dynamic analysis (the first stage) with a multi-body subject-specific lower limb model (the second stage), was used to calculate medial and lateral compartment contact forces. The validation was performed by direct comparison of model predictions and experimental measurement of medial and lateral compartment contact forces during normal and turning gait. The model predictions of both medial and lateral contact forces showed strong correlations with experimental measurements in normal gait (r = 0.75 and 0.71) and in turning gait trials (r = 0.86 and 0.72), even though the current technique over-estimated medial compartment contact forces in swing phase. The correlation coefficient, Sprague and Geers metrics, and root mean squared error indicated that the lateral contact forces were predicted better than medial contact forces in comparison with the experimental measurements during both normal and turning gait trials.

  7. LOFAR facet calibration

    CERN Document Server

    van Weeren, R J; Hardcastle, M J; Shimwell, T W; Rafferty, D A; Sabater, J; Heald, G; Sridhar, S S; Dijkema, T J; Brunetti, G; Brüggen, M; Andrade-Santos, F; Ogrean, G A; Röttgering, H J A; Dawson, W A; Forman, W R; de Gasperin, F; Jones, C; Miley, G K; Rudnick, L; Sarazin, C L; Bonafede, A; Best, P N; Bîrzan, L; Cassano, R; Chyży, K T; Croston, J H; Ensslin, T; Ferrari, C; Hoeft, M; Horellou, C; Jarvis, M J; Kraft, R P; Mevius, M; Intema, H T; Murray, S S; Orrú, E; Pizzo, R; Simionescu, A; Stroe, A; van der Tol, S; White, G J

    2016-01-01

    LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short baseline coverage to map diffuse extended emission. However, producing high-quality deep images is challenging due to the presence of direction dependent calibration errors, caused by imperfect knowledge of the station beam shapes and the ionosphere. Furthermore, the large data volume and presence of station clock errors present additional difficulties. In this paper we present a new calibration scheme, which we name facet calibration, to obtain deep high-resolution LOFAR High Band Antenna images using the Dutch part of the array. This scheme solves and corrects the direction dependent errors in a number of facets that cover the observed field of view. Facet calibration provides close to thermal noise limited images for a typical 8 hr observing run at $\\sim$ 5arcsec resolu...

  8. Fusion angle affects intervertebral adjacent spinal segment joint forces-Model-based analysis of patient specific alignment.

    Science.gov (United States)

    Senteler, Marco; Weisse, Bernhard; Rothenfluh, Dominique A; Farshad, Mazda T; Snedeker, Jess G

    2017-01-01

    This study addresses the hypothesis that adjacent segment intervertebral joint loads are sensitive to the degree of lordosis that is surgically imposed during vertebral fusion. Adjacent segment degeneration is often observed after lumbar fusion, but a causative mechanism is not yet clearly evident. Altered kinematics of the adjacent segments and potentially nonphysiological mechanical joint loads have been implicated in this process. However, little is known of how altered alignment and kinematics influence loading of the adjacent intervertebral joints under consideration of active muscle forces. This study investigated these effects by simulating L4/5 fusions using kinematics-driven musculoskeletal models of one generic and eight sagittal alignment-specific models. Models featured different spinopelvic configurations but were normalized by body height, masses, and muscle properties. Fusion of the L4/5 segment was implemented in an in situ (22°), hyperlordotic (32°), and hypolordotic (8°) fashion and kinematic input parameters were changed accordingly based on findings of an in vitro investigation. Bending motion from upright standing to 45° forward flexion and back was simulated for all models in intact and fused conditions. Joint loads at adjacent levels and moment arms of spinal muscles experienced changes after all types of fusion. Hypolordotic configuration led to an increase of adjacent segment (L3/4) shear forces of 29% on average, whereas hyperlordotic fusion reduced shear by 39%. Overall, L4/5 in situ fusion resulted in intervertebral joint forces closest to intact loading conditions. An artificial decrease in lumbar lordosis (minus 14° on average) caused by an L4/5 fusion lead to adverse loading conditions, particularly at the cranial adjacent levels, and altered muscle moment arms, in particular for muscles in the vicinity of the fusion. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:131-139, 2017.

  9. Effects of a leaf spring structured midsole on joint mechanics and lower limb muscle forces in running.

    Science.gov (United States)

    Wunsch, Tobias; Alexander, Nathalie; Kröll, Josef; Stöggl, Thomas; Schwameder, Hermann

    2017-01-01

    To enhance running performance in heel-toe running, a leaf spring structured midsole shoe (LEAF) has recently been introduced. The purpose of this study was to investigate the effect of a LEAF compared to a standard foam midsole shoe (FOAM) on joint mechanics and lower limb muscle forces in overground running. Nine male long-distance heel strike runners ran on an indoor track at 3.0 ± 0.2 m/s with LEAF and FOAM shoes. Running kinematics and kinetics were recorded during the stance phase. Absorbed and generated energy (negative and positive work) of the hip, knee and ankle joint as well as muscle forces of selected lower limb muscles were determined using a musculoskeletal model. A significant reduction in energy absorption at the hip joint as well as energy generation at the ankle joint was found for LEAF compared to FOAM. The mean lower limb muscle forces of the m. soleus, m. gastrocnemius lateralis and m. gastrocnemius medialis were significantly reduced for LEAF compared to FOAM. Furthermore, m. biceps femoris showed a trend of reduction in running with LEAF. The remaining lower limb muscles analyzed (m. gluteus maximus, m. rectus femoris, m. vastus medialis, m. vastus lateralis, m. tibialis anterior) did not reveal significant differences between the shoe conditions. The findings of this study indicate that LEAF positively influenced the energy balance in running by reducing lower limb muscle forces compared to FOAM. In this way, LEAF could contribute to an overall increased running performance in heel-toe running.

  10. Translaminar facetal screw (magerl′s fixation

    Directory of Open Access Journals (Sweden)

    Rajasekaran S

    2005-01-01

    Full Text Available Translaminar facet screw fixation (TLFS achieves stabilization of the vertebral motion segment by screws inserted at the base of the spinous process, through the opposite lamina, traversing the facet joint, and ending in the base of the transverse process. It is simple, does not require any specialized equipment, and has the advantages of being a procedure of lesser magnitude, lesser operative time, less cost and few complication rate. Recently there is growing interest in this technique to augment the anterior lumbar fusions to achieve global fusion less invasively. In this review article, we discuss the clinical and biomechanical considerations, surgical technique, indications, contraindications and recent developments of TLFS fixation in lumbar spine fusion.

  11. Creating Joint Leaders Today for a Successful Air Force Tomorrow (1REV)

    Science.gov (United States)

    2016-04-01

    promotion of joint duty officers. Obviously, Title IV was unpopular among senior military leaders. Admiral William Crowe , Chairman of the Joint Chiefs of...Command Screening Board (CSB) The most sweeping change to the CSB since former CSAF General Merrill McPeak created it occurred at CORONA Fall 2008 when

  12. Adaptive gravity and joint stiffness compensation methods for force-controlled arm supports

    NARCIS (Netherlands)

    Lobo Prat, J.; Keemink, Arvid Quintijn Leon; Koopman, Hubertus F.J.M.; Stienen, Arno; Veltink, Petrus H.; Braun, D.; Yu, H.; Campolo, D.

    2015-01-01

    People with muscular weakness can benefit from arm supports that compensate the weight of their arms. Due to the disuse of the arms, passive joint stiffness increases and providing only gravity compensation becomes insufficient to support the arm function. Hence, joint stiffness compensation is also

  13. The effect of foot progression angle on knee joint compression force during walking

    DEFF Research Database (Denmark)

    Koblauch, Henrik; Heilskov-Hansen, Thomas; Alkjær, Tine;

    2013-01-01

    males walked at a fixed speed of 4.5 km/h under three conditions: Normal walking, internally rotated and externally rotated. All gait trials were recorded by six infrared cameras. Net joint moments were calculated by 3D inverse dynamics. The results revealed that the medial knee joint compartment...

  14. Evaluation of three force-position hybrid control methods for a robot-based biological joint-testing system.

    Science.gov (United States)

    Hsieh, Hong-Jung; Hu, Chih-Chung; Lu, Tung-Wu; Lu, Hsuan-Lun; Kuo, Mei-Ying; Kuo, Chien-Chung; Hsu, Horng-Chaung

    2016-06-07

    Robot-based joint-testing systems (RJTS) can be used to perform unconstrained laxity tests, measuring the stiffness of a degree of freedom (DOF) of the joint at a fixed flexion angle while allowing the other DOFs unconstrained movement. Previous studies using the force-position hybrid (FPH) control method proposed by Fujie et al. (J Biomech Eng 115(3):211-7, 1993) focused on anterior/posterior tests. Its convergence and applicability on other clinically relevant DOFs such as valgus/varus have not been demonstrated. The current s1tudy aimed to develop a 6-DOF RJTS using an industrial robot, to propose two new force-position hybrid control methods, and to evaluate the performance of the methods and FPH in controlling the RJTS for anterior/posterior and valgus/varus laxity tests of the knee joint. An RJTS was developed using an industrial 6-DOF robot with a 6-component load-cell attached at the effector. The performances of FPH and two new control methods, namely force-position alternate control (FPA) and force-position hybrid control with force-moment control (FPHFM), for unconstrained anterior/posterior and valgus/varus laxity tests were evaluated and compared with traditional constrained tests (CT) in terms of the number of control iterations, total time and the constraining forces and moments. As opposed to CT, the other three control methods successfully reduced the constraining forces and moments for both anterior/posterior and valgus/varus tests, FPHFM being the best followed in order by FPA and FPH. FPHFM had root-mean-squared constraining forces and moments of less than 2.2 N and 0.09 Nm, respectively at 0° flexion, and 2.3 N and 0.14 Nm at 30° flexion. The corresponding values for FPH were 8.5 N and 0.33 Nm, and 11.5 N and 0.45 Nm, respectively. Given the same control parameters including the compliance matrix, FPHFM and FPA reduced the constraining loads of FPH at the expense of additional control iterations, and thus increased total time, FPA

  15. Application of computational lower extremity model to investigate different muscle activities and joint force patterns in knee osteoarthritis patients during walking.

    Science.gov (United States)

    Nha, Kyung Wook; Dorj, Ariunzaya; Feng, Jun; Shin, Jun Ho; Kim, Jong In; Kwon, Jae Ho; Kim, Kyungsoo; Kim, Yoon Hyuk

    2013-01-01

    Many experimental and computational studies have reported that osteoarthritis in the knee joint affects knee biomechanics, including joint kinematics, joint contact forces, and muscle activities, due to functional restriction and disability. In this study, differences in muscle activities and joint force patterns between knee osteoarthritis (OA) patients and normal subjects during walking were investigated using the inverse dynamic analysis with a lower extremity musculoskeletal model. Extensor/flexor muscle activations and torque ratios and the joint contact forces were compared between the OA and normal groups. The OA patients had higher extensor muscle forces and lateral component of the knee joint force than normal subjects as well as force and torque ratios of extensor and flexor muscles, while the other parameters had little differences. The results explained that OA patients increased the level of antagonistic cocontraction and the adduction moment on the knee joint. The presented findings and technologies provide insight into biomechanical changes in OA patients and can also be used to evaluate the postoperative functional outcomes of the OA treatments.

  16. Application of Computational Lower Extremity Model to Investigate Different Muscle Activities and Joint Force Patterns in Knee Osteoarthritis Patients during Walking

    Directory of Open Access Journals (Sweden)

    Kyung Wook Nha

    2013-01-01

    Full Text Available Many experimental and computational studies have reported that osteoarthritis in the knee joint affects knee biomechanics, including joint kinematics, joint contact forces, and muscle activities, due to functional restriction and disability. In this study, differences in muscle activities and joint force patterns between knee osteoarthritis (OA patients and normal subjects during walking were investigated using the inverse dynamic analysis with a lower extremity musculoskeletal model. Extensor/flexor muscle activations and torque ratios and the joint contact forces were compared between the OA and normal groups. The OA patients had higher extensor muscle forces and lateral component of the knee joint force than normal subjects as well as force and torque ratios of extensor and flexor muscles, while the other parameters had little differences. The results explained that OA patients increased the level of antagonistic cocontraction and the adduction moment on the knee joint. The presented findings and technologies provide insight into biomechanical changes in OA patients and can also be used to evaluate the postoperative functional outcomes of the OA treatments.

  17. Muscle activation and estimated relative joint force during running with weight support on a lower-body positive pressure treadmill

    DEFF Research Database (Denmark)

    Jensen, Bente Rona; Hovgaard-Hansen, Line; Cappelen, Katrine Louise

    2016-01-01

    Running on a lower-body positive pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg...... muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100, 80, 60, 40 and 20% body-weight (BW). Surface EMG, ground reaction force and running characteristics were measured. Relative knee and ankle joint forces were...... estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and anti-gravity forces. At 20%BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100%BW values. Plantar flexors decreased to 52% and 58% at 20%BW...

  18. Pharmacy faculty workplace issues: findings from the 2009-2010 COD-COF Joint Task Force on Faculty Workforce.

    Science.gov (United States)

    Desselle, Shane P; Peirce, Gretchen L; Crabtree, Brian L; Acosta, Daniel; Early, Johnnie L; Kishi, Donald T; Nobles-Knight, Dolores; Webster, Andrew A

    2011-05-10

    Many factors contribute to the vitality of an individual faculty member, a department, and an entire academic organization. Some of the relationships among these factors are well understood, but many questions remain unanswered. The Joint Task Force on Faculty Workforce examined the literature on faculty workforce issues, including the work of previous task forces charged by the American Association of Colleges of Pharmacy (AACP). We identified and focused on 4 unique but interrelated concepts: organizational culture/climate, role of the department chair, faculty recruitment and retention, and mentoring. Among all 4 resides the need to consider issues of intergenerational, intercultural, and gender dynamics. This paper reports the findings of the task force and proffers specific recommendations to AACP and to colleges and schools of pharmacy.

  19. Comparison of Upper Limb Joint Forces During Straight Line and Turning Wheelchair Maneuvers

    Science.gov (United States)

    2007-11-02

    epicondyle, lateral epicondyle, radial styloid, ulnar styloid and the second metacarpophalangeal joint of the subjects [11]. Another three markers...Gellman, D. R. Chandler, L. Petrasek, I. Sie, R. Adkins, R. L. Waters, “Carpal tunnel syndrome in paraplegia patients,” J. Bone Joint Surg. Am...propulsion during fatigue,” Arch. Phys. Med. Rehabil., vol. 75, pp.85-93, 1994. [5] R. S. Burnham, R. D. Steadward, “Upper extremity peripheral nerve

  20. Time, Space, and Force Considerations for a Joint Force Commander’s Air Operations in a Counterinsurgency

    Science.gov (United States)

    2009-05-04

    end of the range of military operations ( ROMO ), particularly Counter-Insurgency (COIN), the JTF has many options when deciding how to conduct air...few in number, and are severely hampered by the elements. The desert environment may be an ideal location for them, but wind , rain, and clouds...simultaneously, and different portions of the ROMO . One unit in the AO may be establishing a new police force, while another is conducting a strike against a

  1. A study of the motion pivot in the spine——The measurement of the angle between the vertebra body and the inferior articular facet and its application in the spinal manipulation

    Institute of Scientific and Technical Information of China (English)

    WeiYizong

    2004-01-01

    spinal motion pivot, spinal manipulation, the angle of facet joint, force direction, cylinder pivot motion theory The spinal joint consists of a disc and posterior facet joints. It is the biomechanical structure that enables the spine with six (6) freedoms of movements of flexion/extension, side bends and rotations. We identified that the same spinal joints initiate, eliminate and control spinal movement. These four joints are the atlanto-occipital and the atlanto-odontoid joints, C7/T 1, T12/L1 and L5/S1. The word“pivot”is commonly used to describe an important ruruing porint or matter in Chinese language.We define the above four joints as“pivots” in this article.The joints are briefed as“Occipital-vertebral pivot”(atlanto-occipital and atlanto-odontoid joint),“cervicalthoracic pivot” (C7/T1),“thoracic-lumbar pivot” (T12/L1)and“lumbar-sacrum pivot”(L5/S1). After measuring 20 human spinal columns (dry bones), observing the angle between the vertebral body and the inferior articular faeet,reviewing the spinal anatomy and biomechanics and analyzing the Chinese spinal manipulation techniques and theory, the following is our report:

  2. Psychophysical testing of visual prosthetic devices: a call to establish a multi-national joint task force

    Science.gov (United States)

    Rizzo, Joseph F., III; Ayton, Lauren N.

    2014-04-01

    Recent advances in the field of visual prostheses, as showcased in this special feature of Journal of Neural Engineering , have led to promising results from clinical trials of a number of devices. However, as noted by these groups there are many challenges involved in assessing vision of people with profound vision loss. As such, it is important that there is consistency in the methodology and reporting standards for clinical trials of visual prostheses and, indeed, the broader vision restoration research field. Two visual prosthesis research groups, the Boston Retinal Implant Project (BRIP) and Bionic Vision Australia (BVA), have agreed to work cooperatively to establish a multi-national Joint Task Force. The aim of this Task Force will be to develop a consensus statement to guide the methods used to conduct and report psychophysical and clinical results of humans who receive visual prosthetic devices. The overarching goal is to ensure maximum benefit to the implant recipients, not only in the outcomes of the visual prosthesis itself, but also in enabling them to obtain accurate information about this research with ease. The aspiration to develop a Joint Task Force was first promulgated at the inaugural 'The Eye and the Chip' meeting in September 2000. This meeting was established to promote the development of the visual prosthetic field by applying the principles of inclusiveness, openness, and collegiality among the growing body of researchers in this field. These same principles underlie the intent of this Joint Task Force to enhance the quality of psychophysical research within our community. Despite prior efforts, a critical mass of interested parties could not congeal. Renewed interest for developing joint guidelines has developed recently because of a growing awareness of the challenges of obtaining reliable measurements of visual function in patients who are severely visually impaired (in whom testing is inherently noisy), and of the importance of

  3. Compressive Force With 2-Screw and 3-Screw Subtalar Joint Arthrodesis With Headless Compression Screws.

    Science.gov (United States)

    Matsumoto, Takumi; Glisson, Richard R; Reidl, Markus; Easley, Mark E

    2016-12-01

    Joint compression is an essential element of successful arthrodesis. Although subtalar joint compression generated by conventional screws has been quantified in the laboratory, compression obtainable with headless screws that rely on variable thread pitch to achieve bony contact has not been assessed. This study measured subtalar joint compression achieved by 2 posteriorly placed contemporary headless, variable-pitch screws, and quantified additional compression gained by placing a third screw anteriorly. Ten, unpaired fresh-frozen cadaveric subtalar joints were fixed sequentially using 2 diverging posterior screws (one directed into the talar dome, the other into the talar neck), 2 parallel posterior screws (both ending in the talar dome), and 2 parallel screws with an additional anterior screw inserted from the plantar calcaneus into the talar neck. Joint compression was quantified directly during screw insertion using a novel custom-built measuring device. The mean compression generated by 2 diverging posterior screws was 246 N. Two parallel posterior screws produced 294 N of compression, and augmentation of that construct with a third, anterior screw increased compression to 345 N (P < .05). Compression subsequent to 2-screw fixation was slightly less than that reported previously for subtalar joint fixation with 2 conventional lag screws, but was comparable when a third screw was added. Under controlled testing conditions, 2 tapered, variable-pitch screws generated somewhat less compression than previously reported for 2-screw fixation with conventional headed screws. A third screw placed anteriorly increased compression significantly. Because headless screws are advantageous where prominent screw heads are problematic, such as the load-bearing surface of the foot, their effectiveness compared to other screws should be established to provide an objective basis for screw selection. Augmenting fixation with an anterior screw may be desirable when conditions for

  4. The Many Facets of PISA

    Science.gov (United States)

    Berliner, David C.

    2015-01-01

    Trying to understand PISA is analogous to the parable of the blind men and the elephant. There are many facets of the PISA program, and thus many ways to both applaud and critique this ambitious international program of assessment that has gained enormous importance in the crafting of contemporary educational policy. One of the facets discussed in…

  5. Faceted Taxonomy-Based Sources

    Science.gov (United States)

    Tzitzikas, Yannis

    The objective of this chapter is to explain the underlying mathematical structure of faceted taxonomy-based sources and to provide some common notions and notations that are used in some parts of the book. Subsequently, and on the basis of the introduced formalism, this chapter describes the interaction between a user and an information source that supports dynamic taxonomies and faceted search.

  6. Active Vibration Control of a Large Flexible Manipulator by Inertial Force and Joint Torque. Ph.D. Thesis

    Science.gov (United States)

    Lee, Soo Han

    1988-01-01

    The efficiency and positional accuracy of a lightweight flexible manipulator are limited by its flexural vibrations, which last after a gross motion is completed. The vibration delays subsequent operations. In the proposed work, the vibration is suppressed by inertial force of a small arm in addition to the joint actuators and passive damping treatment. The proposed approach is: (1) Dynamic modeling of a combined system, a large flexible manipulator and a small arm, (2) Determination of optimal sensor location and controller algorithm, and (3) Verification of the fitness of model and the performance of controller.

  7. A Common Set of Core Values - The Foundation for a More Effective Joint Force

    Science.gov (United States)

    2015-05-18

    Iraqi Freedom, Cobra II, they describe that despite the heralded jointness of the operations the Army and Marine Corps essentially fought service...changed without the resulting 10 Michael R. Gordon and General (Ret.) Bernard E. Trainor, Cobra II...cornerstone, the bedrock, and the heart of our character.”16 Core 12 National Defense University

  8. Expeditionary Operations Require Joint Force Capabilities in the Future Operating Environment

    Science.gov (United States)

    2013-03-01

    point for civilian and military expeditions. Chapter Two looks at the existing joint expeditionary architecture to provide the foundation for what the...Jun., 1989): pp. 893-894, http://www.jstor.org/stable/1873989. Moskos, Charles C., John Allen Williams,and David R.Segal, eds. "The Postmodern

  9. Is it possible to reduce the knee joint compression force during level walking with hiking poles?

    DEFF Research Database (Denmark)

    Jensen, S B; Henriksen, M; Aaboe, J;

    2010-01-01

    Walking with hiking poles has become a popular way of exercising. Walking with poles is advocated as a physical activity that significantly reduces the loading of the hip, knee and ankle joints. We have previously observed that pole walking does not lead to a reduction of the load on the knee joi...

  10. Quantitative morphometric analysis of the lumbar vertebral facets and evaluation of feasibility of lumbar spinal nerve root and spinal canal decompression using the Goel intraarticular facetal spacer distraction technique: A lumbar/cervical facet comparison

    Directory of Open Access Journals (Sweden)

    Savni R Satoskar

    2014-01-01

    Full Text Available Objective : The authors evaluate the anatomic subtleties of lumbar facets and assess the feasibility and effectiveness of use of ′Goel facet spacer′ in the treatment of degenerative spinal canal stenosis. Materials and Methods : Twenty-five lumbar vertebral cadaveric dried bones were used for the purpose. A number of morphometric parameters were evaluated both before and after the introduction of Goel facet spacers within the confines of the facet joint. Results : The spacers achieved distraction of facets that was more pronounced in the vertical perspective. Introduction of spacers on both sides resulted in an increase in the intervertebral foraminal height and a circumferential increase in the spinal canal dimensions. Additionally, there was an increase in the disc space or intervertebral body height. The lumbar facets are more vertically and anteroposteriorly oriented when compared to cervical facets that are obliquely and transversely oriented. Conclusions : Understanding the anatomical peculiarities of the lumbar and cervical facets can lead to an optimum utilization of the potential of Goel facet distraction arthrodesis technique in the treatment of spinal degenerative canal stenosis.

  11. Comparison of Applied Forces on Selective Joints and Muscles of Drivers During Clutching of MF285 and MF399 Tractors

    Directory of Open Access Journals (Sweden)

    H Fallahi

    2015-03-01

    Full Text Available In this research, the imposed forces on three muscles including: Gastrocnemius muscle, Trapezius muscle and Quadratus lumborum of the tractor drivers during clutching have been studied. The sample included 30 persons and the research was conducted on two domestic tractors including: MF285 and MF399 models. The clutching forces for these tractors were measured as 340 N and 290 N, respectively. The difference between drivers’ knee angle of the two tractors was proved significant at the one percent level. The decrease of pain threshold after 30 seconds and 60 seconds clutching and 60 seconds rest after clutching in MF285 tractor in all three muscles were more than that of MF399 tractor. The impact of clutching on the average decrease of pain threshold, among all the drivers, and for all time intervals, during and after clutching in the Quadratus lumborum muscle for both tractors was more than the other two muscles. In order to reduce the imposed force of clutching for MF285 tractor, some modifications is suggested. In this regard the force transfer joint between the pedal and the disc in the mechanism of clutching can be replaced with one made of cast iron.

  12. Honing the Dagger: The formation of a Standing Joint Special Operations Task Force Headquarters

    Science.gov (United States)

    2007-11-02

    even on the ground; while transloading the assault force from the C-130’s, a third 8 Samuel M...College, 2003. Barnett, Frank R., B. Hugh Tovar , and Richard H. Shultz, eds. Special Operations in U.S. Strategy. Washington, D.C.: National Defense...Staff, 2002. 40 Katz, Samuel M. Today’s Green Berets: The U.S. Army’s Special Forces Groups (Airborne). Hong Kong: Concord Publications, 1996

  13. Targeted Radiofrequency Ablation as an Adjunct in Treatment of Lumbar Facet Cysts.

    Science.gov (United States)

    Hatgis, Jesse; Granville, Michelle; Berti, Aldo; Jacobson, Robert E

    2017-06-06

    Lumbar facet cysts are frequently found in patients with facet degeneration and segmental instability. When the facet cyst is localized in the neural foramina and lateral recess or becomes large, it can cause radiculopathy or neurogenic claudication. These symptomatic cysts are typically treated interventionally with drainage and a corticosteroid injection or attempts via overinflation to rupture the cyst; however, these procedures have a significant recurrence rate (up to 50%) and often need to be repeated or lead to lumbar surgery if unsuccessful.   This is the first report of using targeted radiofrequency (RF) current as an adjunct to cyst drainage. Although RF has been used for years to treat facet pain indirectly by targeting the medial facet nerve branches, with this technique, under image guidance, the actual cyst is percutaneously drained and then cauterized along with the associated facet capsule, where the original cyst developed. This has improved overall results with less cyst recurrence than previous percutaneous methods and was documented with both intermediate and long-term followup clinically and with magnetic resonance imaging (MRI) scans. This report reviews the underlying anatomy and pathology of the facet joint relating to the development of facet cysts and how current percutaneous treatments for lumbar facet cysts can be supplemented and improved by adding targeted RF ablation to the percutaneous options available to treat a lumbar facet cyst.

  14. Conference-EC-US Task Force Joint US-EU Workshop on Metabolomics and Environmental Biotechnology

    Energy Technology Data Exchange (ETDEWEB)

    PI: Lily Y. Young

    2009-06-04

    Since 1990, the EC-US Task Force on Biotechnology Research has been coordinating transatlantic efforts to guide and exploit the ongoing revolution in biotechnology and the life sciences. The Task Force was established in June 1990 by the European Commission and the White House Office of Science and Technology Policy. The Task Force has acted as an effective forum for discussion, coordination, and development of new ideas for the last 18 years. Task Force members are European Commission and US Government science and technology administrators who meet annually to enhance communication across the Atlantic, and to encourage collaborative research. Through sponsoring workshops, and other activities, the Task Force also brings together scientific leaders and early career researchers from both sides of the Atlantic to forecast research challenges and opportunities and to promote better links between researchers. Over the years, by keeping a focus on the future of science, the Task Force has played a key role in establishing a diverse range of emerging scientific fields, including biodiversity research, neuroinformatics, genomics, nanobiotechnology, neonatal immunology, transkingdom molecular biology, biologically-based fuels, and environmental biotechnology. The EC-US Task Force has sponsored a number of Working Groups on topics of mutual transatlantic interest. The idea to create a Working Group on Environmental Biotechnology research was discussed in the Task Force meeting of October 1993. The EC-US Working Group on Environmental Biotechnology set as its mission 'To train the next generation of leaders in environmental biotechnology in the United States and the European Union to work collaboratively across the Atlantic.' Since 1995, the Working Group supported three kinds of activities, all of which focus one early career scientists: (1) Workshops on the use of molecular methods and genomics in environmental biotechnology; (2) Short courses with theoretical

  15. Joint Force Quarterly: The Greater Middle East. Number 24. Spring 2000.

    Science.gov (United States)

    2000-01-01

    Rwanda, Somalia, Colombia , and Kosovo. Despite and dream of an experimental force developed in a which appeared in the last issue was, in a word, the...economic dead and a million homeless in 1970. were vastly upgraded. development, overpopulation , and The 1970-71 clash had Cold War poverty. It was

  16. Distribution of joint local and total size and of extension for avalanches in the Brownian force model

    Science.gov (United States)

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d , driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ0=5 /3 and τ =7 /4 , depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d =1 ) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P (ℓ ) ˜ℓ-3 at small ℓ . Most of our results are tested in a numerical simulation in dimension d =1 .

  17. Distribution of joint local and total size and of extension for avalanches in the Brownian force model.

    Science.gov (United States)

    Delorme, Mathieu; Le Doussal, Pierre; Wiese, Kay Jörg

    2016-05-01

    The Brownian force model is a mean-field model for local velocities during avalanches in elastic interfaces of internal space dimension d, driven in a random medium. It is exactly solvable via a nonlinear differential equation. We study avalanches following a kick, i.e., a step in the driving force. We first recall the calculation of the distributions of the global size (total swept area) and of the local jump size for an arbitrary kick amplitude. We extend this calculation to the joint density of local and global sizes within a single avalanche in the limit of an infinitesimal kick. When the interface is driven by a single point, we find new exponents τ_{0}=5/3 and τ=7/4, depending on whether the force or the displacement is imposed. We show that the extension of a "single avalanche" along one internal direction (i.e., the total length in d=1) is finite, and we calculate its distribution following either a local or a global kick. In all cases, it exhibits a divergence P(ℓ)∼ℓ^{-3} at small ℓ. Most of our results are tested in a numerical simulation in dimension d=1.

  18. 痞满脾胃虚弱证临床症状与胸椎小关节紊乱的关系与手法治疗研究%Research of the manual therapy and the relationship between clinical symptoms of weak spleen and stomach and thoracic facet joint disorders

    Institute of Scientific and Technical Information of China (English)

    周学龙; 王明杰; 韦明; 何建红; 孙刚; 孙利伟

    2013-01-01

    Objective:To investigate the the relationship between clinical symptoms of weak spleen and stomach and thoracic facet joint disorders and the effect of the manual therapy. Methods: The patients who meet the diagnostic criteria as subjects, survey the probability of concurrent thoracic facet joint disorders in patients, and used manual therapy to treat the local signs, evaluated the efficacy before and after treatment. Results: In 100 patients, there are 32 cases with thoracic spinous process skew, prominent and paraspinal tenderness or muscle tension and other local signs, accounted for 32% of those surveyed; which 32 patients with thoracic facet joint disorders were given manipulation therapy, the main symptom scores before and after treatment there was a significant difference (P<0.01), total efficiency was 87.5%. Conclusion:Weak spleen and stomach related with thoracic facet joint disorders, manual therapy can effectively improve the clinical syndrome of weak spleen and stomach, but the exact mechanism remains to be further studied.%目的:调查痞满脾胃虚弱证临床症状与胸椎小关节紊乱的关系和观察手法整复胸椎小关节紊乱对痞满脾胃虚弱证临床症状的影响。方法:以符合痞满脾胃虚弱证诊断标准者为调查对象,统计调查对象中并发胸椎小关节紊乱的机率,并对具有胸椎小关节紊乱局部体征者进行手法治疗,以治疗前后的症状积分情况评价疗效。结果:在调查的100例痞满脾胃虚弱证患者中,有32例具有胸椎棘突偏歪、后突和棘旁压痛或肌紧张等局部体征,占调查人数的32%;其中32例痞满脾胃虚弱证并胸椎小关节紊乱患者经手法整复其胸椎小关节紊乱后,治疗前后主要症状积分比较有显著性差异(P<0.01),总有效率为87.5%。结论:痞满脾胃虚弱证与胸椎小关节紊乱有关,手法整复胸椎小关节紊乱可有效地改善痞满脾胃虚弱证患者的临床症

  19. 针刺夹脊穴联合推拿手法治疗胸椎小关节紊乱的临床观察%Clinical observation on acupuncture at Jiaji (EX-B 2) points plus tuina in treating thoracic facet joint disorder

    Institute of Scientific and Technical Information of China (English)

    周伟成; 诸剑芳

    2016-01-01

    目的:观察针刺夹脊穴联合推拿整复手法治疗胸椎小关节紊乱的临床疗效,为本病的针灸治疗提供新的临床证据。方法:将106例符合纳入标准的胸椎小关节紊乱患者按随机数字表随机分为观察组和对照组。对照组予以单纯的推拿整复手法治疗,观察组在对照组推拿整复手法前予以针刺夹脊穴治疗。两组均每日1次,治疗3次后观察症状、体征的改善情况及疗效。结果:治疗后,两组患者8个症状、体征积分均与本组治疗前均有统计学差异(P<0.01);观察组患者的各个症状、体征积分均明显低于对照组,组间差异均有统计学意义(P<0.05)。观察组治愈率为50.9%,对照组为26.4%,两组治愈率差异有统计学意义(P<0.05)。结论:针刺联合手法整复治疗胸椎小关节紊乱能使胸椎重新达到生物力学平衡,充分发挥针灸推拿的联合作用,显著地提高临床疗效。%Objective:To observe the clinical effects of acupuncture at Jiaji (EX-B 2) points plus tuina manipulation for thoracic facet joint disorder, and get new clinical evidence for treatment of thoracic facet joint disorder. Methods:Totally 106 patients with thoracic facet joint disorder were randomly allocated into an observation group and a control group based on the random number table. Patients in the control group were treated by tuina manipulation, while those in the observation group were treated by acupuncture at Jiaji (EX-B 2) points before tuina manipulation. Patients in the two groups were treated once a day. The improvements of signs and symptoms and the efficacy were observed after 3 treatments. Results:After treatment, there were intra-group statistical differences in scores of 8 signs and symptoms in both groups (P<0.01); the score of each item in the observation group was lower than that in the control group, and there was statistical significance in the inter-group difference (P<0

  20. Does high weight loss in older adults with knee osteoarthritis affect bone-on-bone joint loads and muscle forces during walking?

    Science.gov (United States)

    Messier, Stephen P.; Legault, Claudine; Loeser, Richard F.; Van Arsdale, Stephanie J.; Davis, Cralen; Ettinger, Walter H.; DeVita, Paul

    2012-01-01

    Objective The aim of this study was to examine the effects of high weight loss on knee joint loads during walking in participants with knee OA. Design Data were obtained from a subset of participants enrolled in the Arthritis, Diet, and Activity Promotion Trial (ADAPT). Complete baseline and 18 month follow-up data were obtained on 76 sedentary, overweight or obese older adults with radiographic knee OA. Three-dimensional gait analysis was used to calculate knee joint forces and moments. The cohort was divided into high (> 5%), low (knee compressive forces with greater weight loss (p = 0.05). The difference in compressive forces between the high weight loss and no weight loss groups was due primarily to lower hamstring forces (p = 0.04). Quadriceps forces were similar between the groups at 18 month follow-up. There was no difference between the groups in 18-month joint space width or Kellgren-Lawrence scores. Conclusions These results suggest that a 10% weight loss in an overweight and obese osteoarthritic population elicits positive changes in the mechanical pathway to knee osteoarthritis by having lower knee joint compressive loads during walking compared to low and no weight loss groups. The difference in compressive forces was due, in large part, to reductions in hamstring co-contraction during the initial portion of the stance phase. PMID:21134477

  1. Joint ventures in medical services.

    Science.gov (United States)

    Rublee, D A

    1987-01-01

    This paper is an overview of joint-venture activity in healthcare, describing trends in joint ventures and raising issues for physicians. The purposes are to discuss the major current facets of joint-venture alliances in healthcare and to identify policy issues that arise from the trend to use joint ventures as an organizational tool. Speculation is made about the future role of joint ventures in the organization of healthcare.

  2. Maritime Trade Defense: Establishing the Joint Force Maritime Trade Component Commander

    Science.gov (United States)

    2012-05-04

    continued to grow. Maersk Line , a leading company in container ship development, is set to launch an 18,000 TEU container ship in 2013, named the...by Sam J. Tangredi et al. (Washington DC: National Defense University, 2002), 137. 25 Maersk Line . About Us: About Maersk Line . 2011. http...edited by Andrew Forbes, 153-164. RAAF Fairbairn, Canberra: Australian Defence Force Academy, 2003. Maersk Line . About Us: About Maersk Line . 2011

  3. Expeditionary Forensic Support to Joint Force Commanders: What Changes or Considerations are Warranted?

    Science.gov (United States)

    2012-04-10

    concepts such as Prosecution Support Teams proposed by Judge Advocate Major Steve Berlin, combined with EFL efforts, will synchronize the skills and...Forensic Enterprise DIA Defense Intelligence Agency DNA Deoxyribonucleic acid DoD Department of Defense EFL Expeditionary Forensic Laboratory EOD...Iraq The volume and complexity of IED threats faced by coalition forces in Iraq in the summer of 2003 was beyond the conventional skill -set of a

  4. Joint Force Quarterly, Issue 49, 2nd Quarter 2008: Focus on Airpower

    Science.gov (United States)

    2008-04-01

    Services, agencies, and departments be ready to identify the newly minted national security professionals and place them in posi- tions using their new...Robert Murphy, Diplomat Among Warriors ( Garden City, NY: Doubleday and Company, 1964), 68. 24 Franklin D. Roosevelt to Harry Hopkins, March 27, 1941...Trial and Hope ( Garden City, NY: Doubleday, 1956), 339. 21 Robert F. Futrell, The United States Air Force in Korea 1950–1953 (New York: Duell, Sloan

  5. Getting There is Only Half the Battle: Improving Forcible Entry Capability for Joint Force 2020

    Science.gov (United States)

    2013-04-01

    of some 3100 miles. Countries around the world engage in loud and sustained protest, but a threatened attack by Israel and the United States to stop...DMZ. Iran attempts to widen the conflict by launching missiles at the GCC states and Israel , but most are destroyed by friendly missile defenses...America’s Light Forces for Rapid- Reaction Missions - Executive Summary (Santa Monica, CA: RAND Arroyo Center, 2001), 1. 13 Ibid., 25, 31. 51 Space

  6. Micro- and nanodomain imaging in uniaxial ferroelectrics: Joint application of optical, confocal Raman, and piezoelectric force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shur, V. Ya., E-mail: vladimir.shur@urfu.ru; Zelenovskiy, P. S. [Ferroelectric Laboratory, Institute of Natural Sciences, Ural Federal University, 620000 Ekaterinburg (Russian Federation)

    2014-08-14

    The application of the most effective methods of the domain visualization in model uniaxial ferroelectrics of lithium niobate (LN) and lithium tantalate (LT) family, and relaxor strontium-barium niobate (SBN) have been reviewed in this paper. We have demonstrated the synergetic effect of joint usage of optical, confocal Raman, and piezoelectric force microscopies which provide extracting of the unique information about formation of the micro- and nanodomain structures. The methods have been applied for investigation of various types of domain structures with increasing complexity: (1) periodical domain structure in LN and LT, (2) nanodomain structures in LN, LT, and SBN, (3) nanodomain structures in LN with modified surface layer, (4) dendrite domain structure in LN. The self-assembled appearance of quasi-regular nanodomain structures in highly non-equilibrium switching conditions has been considered.

  7. Impact of the Joint Task Force on Undergraduate Physics Programs for Innovation and Entrepreneurship Education in Physics

    Science.gov (United States)

    Arion, Douglas

    The Joint Task Force on Undergraduate Physics Programs has worked diligently to develop recommendations for what physics programs could and should be doing to prepare graduates for 21st century careers. While the `traditional' physics curriculum has served for many years, the demands of the new workforce, and the recognition that only a few percent of physics students actually become faculty - the vast majority entering the workforce and applying their skills to a very diverse range of problems, projects, and products - implies that a review of the education undergraduates receives is in order. The outcomes of this study point to the need to provide greater connection between the education process and the actual skills, knowledge, and abilities that the workplace demands. This presentation will summarize these considerations, and show how entrepreneurship and innovation programs and curricula are a particularly effective means of bringing these elements to physics students.

  8. The Association of Academic Health Sciences Libraries' legislative activities and the Joint Medical Library Association/Association of Academic Health Sciences Libraries Legislative Task Force.

    Science.gov (United States)

    Zenan, Joan S

    2003-04-01

    The Association of Academic Health Sciences Libraries' (AAHSL's) involvement in national legislative activities and other advocacy initiatives has evolved and matured over the last twenty-five years. Some activities conducted by the Medical Library Association's (MLA's) Legislative Committee from 1976 to 1984 are highlighted to show the evolution of MLA's and AAHSL's interests in collaborating on national legislative issues, which resulted in an agreement to form a joint legislative task force. The history, work, challenges, and accomplishments of the Joint MLA/AAHSL Legislative Task Force, formed in 1985, are discussed.

  9. Muscle Activation and Estimated Relative Joint Force During Running with Weight Support on a Lower-Body Positive-Pressure Treadmill.

    Science.gov (United States)

    Jensen, Bente R; Hovgaard-Hansen, Line; Cappelen, Katrine L

    2016-08-01

    Running on a lower-body positive-pressure (LBPP) treadmill allows effects of weight support on leg muscle activation to be assessed systematically, and has the potential to facilitate rehabilitation and prevent overloading. The aim was to study the effect of running with weight support on leg muscle activation and to estimate relative knee and ankle joint forces. Runners performed 6-min running sessions at 2.22 m/s and 3.33 m/s, at 100%, 80%, 60%, 40%, and 20% body weight (BW). Surface electromyography, ground reaction force, and running characteristics were measured. Relative knee and ankle joint forces were estimated. Leg muscles responded differently to unweighting during running, reflecting different relative contribution to propulsion and antigravity forces. At 20% BW, knee extensor EMGpeak decreased to 22% at 2.22 m/s and 28% at 3.33 m/s of 100% BW values. Plantar flexors decreased to 52% and 58% at 20% BW, while activity of biceps femoris muscle remained unchanged. Unweighting with LBPP reduced estimated joint force significantly although less than proportional to the degree of weight support (ankle). It was concluded that leg muscle activation adapted to the new biomechanical environment, and the effect of unweighting on estimated knee force was more pronounced than on ankle force.

  10. An electromyogram-driven musculoskeletal model of the knee to predict in vivo joint contact forces during normal and novel gait patterns.

    Science.gov (United States)

    Manal, Kurt; Buchanan, Thomas S

    2013-02-01

    Computational models that predict internal joint forces have the potential to enhance our understanding of normal and pathological movement. Validation studies of modeling results are necessary if such models are to be adopted by clinicians to complement patient treatment and rehabilitation. The purposes of this paper are: (1) to describe an electromyogram (EMG)-driven modeling approach to predict knee joint contact forces, and (2) to evaluate the accuracy of model predictions for two distinctly different gait patterns (normal walking and medial thrust gait) against known values for a patient with a force recording knee prosthesis. Blinded model predictions and revised model estimates for knee joint contact forces are reported for our entry in the 2012 Grand Challenge to predict in vivo knee loads. The EMG-driven model correctly predicted that medial compartment contact force for the medial thrust gait increased despite the decrease in knee adduction moment. Model accuracy was high: the difference in peak loading was less than 0.01 bodyweight (BW) with an R(2 )= 0.92. The model also predicted lateral loading for the normal walking trial with good accuracy exhibiting a peak loading difference of 0.04 BW and an R(2 )= 0.44. Overall, the EMG-driven model captured the general shape and timing of the contact force profiles and with accurate input data the model estimated joint contact forces with sufficient accuracy to enhance the interpretation of joint loading beyond what is possible from data obtained from standard motion capture studies.

  11. Force

    CERN Document Server

    Graybill, George

    2007-01-01

    Forces are at work all around us. Discover what a force is, and different kinds of forces that work on contact and at a distance. We use simple language and vocabulary to make this invisible world easy for students to ""see"" and understand. Examine how forces ""add up"" to create the total force on an object, and reinforce concepts and extend learning with sample problems.

  12. ’Seams’ Of Inefficiency and Joint Interagency Task Force (JIATF) Operations

    Science.gov (United States)

    2006-05-31

    9 3. Figure 3: Operation Mayan Jaguar……………………..………… 14 4. Figure 4: Proposed JIATF East JOA …………………………….. 18 5. Figure 5...military forces from engaging in any civil law enforcement activities. By modifying the Act, President Reagan formally directed U.S. intelligence...kicked off operation MAYAN JAGUAR (See Figure 3). Combined CD Operations OP Mayan Jaguar with Guatemala, Feb 2002 92˚ West - JIATF East coordinated

  13. Observations on the Rapid Deployment Joint Task Force: Origins, Direction, and Mission,

    Science.gov (United States)

    1982-06-01

    Readiness Items Not Avail. Not Avail. Not Avail. aData are from Secretary Weinberger’s Annual Report to Congress, [1] which does not break out separately...8217,’’," ’’,. .’ . ..’ .’ :2 -, .-- , - .. . . • • , - 22 - the status of the big Soviet-invasion scenario (in one form or the other) will continue to be special. .9 O...European missions are only a small percentage of total NATO forces--and, in most cases, not particularly well suited to a big war in Europe in any event; (2

  14. Joint Force Quarterly. Number 6, Autumn/Winter 1994-95

    Science.gov (United States)

    1994-11-01

    as culture and the preferences it teaches and expresses, mean that planners and their political mas- ters do not confront a tabula rasa when they... Roles , Missions, and JTFs: Unintended Consequences by Steven L. Canby C O N T E N T S JFQ Page 2 - no folio P H O T O C R E D I T S The cover photo...are the changing role of long-stand- ing alliances and a range of situations in which we are called on to use military force. AWord from th as we move

  15. System for intraoperative evaluation of soft-tissue-generated forces during total hip arthroplasty by measurement of the pressure distribution in artificial joints.

    Science.gov (United States)

    Otake, Yoshito; Suzuki, Naoki; Hattori, Asaki; Miki, Hidenobu; Yamamura, Mitsuyoshi; Yonenobu, Kazuo; Ochi, Takahiro; Sugano, Nobuhiko

    2007-01-01

    A system for evaluating the soft-tissue-generated forces at the hip joint was developed. The system enabled measurement of contact pressure distribution at hip joint surfaces, as well as evaluation of the artificial hip joint condition during total hip arthroplasty (THA). First, a pressure sensor module that forms part of the artificial joint was constructed. Eight small pressure sensors were installed in the spherical head component of the ball-and-socket joint. Next, software for recording and visualizing the detected pressures at 1-millisecond intervals was developed. The pressure distribution was displayed in real time via 3D computer graphics on a monitor. The system enabled intuitive recognition of the direction of soft-tissue-generated forces and pressure distribution in three dimensions. Accuracy tests were conducted using a high-accuracy 6-degree-of-freedom positioning device and digital force gauge. The error between the applied loads and measured forces was 3.42 +/- 3.26 N (mean +/- standard deviation) for each coordinate in 10 trials involving load application from 10 different directions. Next, a clinical evaluation was conducted during THA. The relative positions of the cup and stem component were measured using a surgical navigation system simultaneously with the pressure measurement. The system allowed real-time acquisition of information regarding the artificial hip joint, as well as comparison of the differences in the hip condition when several types of neck were used. Further improvements to the calibration method should enable more accurate measurements. We believe this system will be a useful tool for selecting an appropriate implant that fits a patient's hip joint or for estimating the risk of complications following surgery.

  16. The Joint Commission has provided a tool to change your work force: are you paying attention?

    Science.gov (United States)

    Decker, P J; Strader, M K

    1998-03-01

    Most health care managers wonder how to change employee "attitudes" so that their staff will be more accountable for patient satisfaction, cost reduction, and quality of care. Employees were trained to function in an industry where the power players were the physician and the administrator and now it is exceedingly difficult to get them to switch their attention to the patient and the payer in a market-driven economy. For hospital managers, the answer may be right at their fingertips: The Joint Commission on Accreditation of Healthcare Organizations' standards demanding that employee competence be objectively measured, proven, tracked & trended, improved, and age specific. A comprehensive competence assessment system can save the health care manager enormous work in measuring fewer things, focusing performance assessment on the 20 percent of things that are true problems, and helping to specifically define certain competencies such as customer focus and cost consciousness so that coaching, training, and giving performance feedback is easier. Developing a comprehensive competence assessment system is a powerful tool to change the culture of organizations. Consequently, it is important that managers be aware of those possibilities before they embark on developing "competencies" or before their organizations get too carried away on redesigning systems to satisfy standards.

  17. Determinants and magnitudes of manual force strengths and joint moments during two-handed standing maximal horizontal pushing and pulling.

    Science.gov (United States)

    Chow, Amy Y; Dickerson, Clark R

    2016-04-01

    Pushing and pulling are common occupational exertions that are increasingly associated with musculoskeletal complaints. This study focuses on the sensitivity of shoulder capacity to gender, handle height, exertion type (push or pull) and handle orientation for these tasks. All factors except for handle orientation influenced unilateral and total manual force strength (p < 0.01), with exertion type being the most influential. Interaction effects also existed between handle height and exertion type. Additionally, joint moments at the shoulders and low back were influenced by all factors studied (p < 0.01), with exertion type again being most influential. Knowledge of the relative influence of multiple factors on shoulder capacity can provide guidance regarding these factors when designing or evaluating occupational pushing and pulling tasks for a diverse population. Practitioner Summary: pushing and pulling comprise nearly half of all manual materials handling tasks. Practitioners often assess, design or modify these tasks while incorporating constraints, including manual force direction and handle interface. This study provides guidance to aid design of pushing and pulling tasks in the context of shoulder physical capacity.

  18. Joint Task Force on Undergraduate Physics Programs: Implications for physics programs and why you should care

    Science.gov (United States)

    Hodapp, Theodore

    2016-03-01

    The content of undergraduate physics programs has not changed appreciably in 50 years, however, the jobs our students take have changed dramatically. Preparing students for careers they are likely to encounter requires physics programs to rethink and in some cases retool to provide an education that will not only educate an individual in the habits of mind and keen sense of how to solve complex technical problems, but also what related skills they will need to be effective in those careers. Do you teach your student how to read or create a budget? How about dealing with a low-performing member of an R&D team? This talk will explore driving forces behind this report, potential implications for physics departments, and practical steps faculty members can take to continue to consider improvements in experiences for our students. This work is supported in part by the National Science Foundation (NSF-1540570).

  19. Traumatic brain injury recorded in the UK Joint Theatre Trauma Registry among the UK Armed Forces.

    Science.gov (United States)

    Hawley, Carol A; de Burgh, H Thomas; Russell, Robert J; Mead, Andrew

    2015-01-01

    To use the UK Joint Theatre Trauma Registry (UK-JTTR) to identify service personnel sustaining traumatic brain injury (TBI) in recent conflicts and to examine injury characteristics, outcomes, and severity measures predictive of survival. Operations HERRICK (Afghanistan) and TELIC (Iraq). The UK-JTTR records data for every UK service person either killed on operations or treated by Defence Medical Services after a trauma call, including those evacuated for inpatient care following traumatic injury. UK-JTTR data were retrospectively analyzed to identify those who sustained TBI. The Mayo system was used to define TBI. Glasgow Coma Scale score, injury severity score, new injury severity score, trauma injury severity score, abbreviated injury scale, and a severity characterization of trauma were used to predict survival. In total, 464 UK service personnel sustained TBI, representing 19% of the 2440 casualties in Afghanistan and Iraq, recorded in the UK-JTTR. Most TBI casualties had moderate-severe TBI (402, 87%). There were 181 (39%) survivors, 56% of these received neurorehabilitation. Improvised explosive devices accounted for 55% of TBIs sustained in Afghanistan and 31% of TBIs in Iraq. Logistic regression analyses were performed using the 412 cases (149 survivors: 263 fatalities) with scores on all severity measures. The best-fitting model was based on trauma injury severity score. A trauma injury severity score more than 11.13 indicates a more than 95% probability of survival. This is the first study of UK combat TBIs between 2003 and 2011. Almost 1 in 5 UK service personnel recorded in the UK-JTTR had TBI; most were moderate-severe. However, mild TBI is likely to be underrepresented in the UK-JTTR. These findings may be used to plan future rehabilitation needs, as almost half the survivors did not receive neurorehabilitation.

  20. Estimation of Joint Forces and Moments for the In-Run and Take-Off in Ski Jumping Based on Measurements with Wearable Inertial Sensors

    Directory of Open Access Journals (Sweden)

    Grega Logar

    2015-05-01

    Full Text Available This study uses inertial sensors to measure ski jumper kinematics and joint dynamics, which was until now only a part of simulation studies. For subsequent calculation of dynamics in the joints, a link-segment model was developed. The model relies on the recursive Newton–Euler inverse dynamics. This approach allowed the calculation of the ground reaction force at take-off. For the model validation, four ski jumpers from the National Nordic center performed a simulated jump in a laboratory environment on a force platform; in total, 20 jumps were recorded. The results fit well to the reference system, presenting small errors in the mean and standard deviation and small root-mean-square errors. The error is under 12% of the reference value. For field tests, six jumpers participated in the study; in total, 28 jumps were recorded. All of the measured forces and moments were within the range of prior simulated studies. The proposed system was able to indirectly provide the values of forces and moments in the joints of the ski-jumpers’ body segments, as well as the ground reaction force during the in-run and take-off phases in comparison to the force platform installed on the table. Kinematics assessment and estimation of dynamics parameters can be applied to jumps from any ski jumping hill.

  1. Faceting diagram for sticky steps

    Directory of Open Access Journals (Sweden)

    Noriko Akutsu

    2016-03-01

    Full Text Available Faceting diagrams for the step-faceting zone, the step droplet zone, and the Gruber-Mullins-Pokrovsky-Talapov (GMPT zone for a crystal surface are obtained by using the density matrix renormalization group method to calculate the surface tension. The model based on these calculations is the restricted solid-on-solid (RSOS model with a point-contact-type step-step attraction (p-RSOS model on a square lattice. The point-contact-type step-step attraction represents the energy gain obtained by forming a bonding state with orbital overlap at the meeting point of the neighboring steps. In the step-faceting zone, disconnectedness in the surface tension leads to the formation of a faceted macrostep on a vicinal surface at equilibrium. The disconnectedness in the surface tension also causes the first-order shape transition for the equilibrium shape of a crystal droplet. The lower zone boundary line (ZBL, which separates the step-faceting zone and the step droplet zone, is obtained by the condition γ 1 = lim n → ∞ γ n / n , where γn is the step tension of the n-th merged step. The upper ZBL, which separates the GMPT zone and the step droplet zone, is obtained by the condition Aq,eff = 0 and Bq,eff = 0, where Aq,eff and Bq,eff represent the coefficients for the | q → | 2 term and the | q → | 3 term, respectively, in the | q → | -expanded form of the surface free energy f eff ( q → . Here, q → is the surface gradient relative to the (111 surface. The reason why the vicinal surface inclined in the 〈101〉 direction does not exhibit step-faceting is explained in terms of the one-dimensional spinless quasi-impenetrable attractive bosons at absolute zero.

  2. /facet: A Generic Facet Browser Including Temporal and Spatial Visualization

    NARCIS (Netherlands)

    Hildebrand, M.

    2007-01-01

    A generic facet browser including temporal and spatial visualization. The existing MultimediaN Eculture demo is updated in two ways: improved visualization of the semantic timeline and added a natural language sentence generator for cluster headers. Relation search interface is also implemente

  3. Regional Military Integration in West Africa: A Case Study of the Multi-National Joint Task Force in the Fight against Boko Haram

    Science.gov (United States)

    2016-06-10

    REGIONAL MILITARY INTEGRATION IN WEST AFRICA: A CASE STUDY OF THE MULTI-NATIONAL JOINT TASK FORCE IN THE FIGHT AGAINST BOKO HARAM......ABSTRACT The militant Jihadist group Boko Haram has established itself as a regional threat in the areas surrounding the Lake Chad Basin (LCB) of

  4. Amsterdam Oxford Joint Rescue Forces: Team description paper: Virtual Robot competition: Rescue Simulation League: RoboCup 2010 and Iran Open

    NARCIS (Netherlands)

    A. Visser; Q. Nguyen; B. Terwijn; M. Hueting; R. Jurriaans; M. van der Veen; O. Formsma; N. Dijkshoorn; S. van Noort; R. Sobolewski; H. Flynn; M. Jankowska; S. Rath; J. de Hoog

    2010-01-01

    With the progress made in active exploration, the robots of the Joint Rescue Forces are capable of making deliberative decisions about the distribution of exploration locations over the team. Experiments have been done which include information exchange between team-members at rendez-vous points. La

  5. THEORY OF INCOMMENSURATE CRYSTAL FACETS

    NARCIS (Netherlands)

    VANSMAALEN, S

    1993-01-01

    The morphology of incommensurately modulated crystals is considered. A surface free energy model is constructed which interprets the stabilization of the incommensurate facets as due to surface pinning of the phase of the modulation wave. The stepped nature of the true crystal surface restricts the

  6. THEORY OF INCOMMENSURATE CRYSTAL FACETS

    NARCIS (Netherlands)

    VANSMAALEN, S

    1993-01-01

    The morphology of incommensurately modulated crystals is considered. A surface free energy model is constructed which interprets the stabilization of the incommensurate facets as due to surface pinning of the phase of the modulation wave. The stepped nature of the true crystal surface restricts the

  7. MID-FACETS OF A SIMPLEX

    Institute of Scientific and Technical Information of China (English)

    李小燕; 何斌吾; 冷岗松

    2004-01-01

    The mid-facet of a simplex in n-dimensional Euclidean space which was introduced quite recently is an important geometric element.An analytic expression for the mid-facet area of a simplex is firstly given.In order to obtain the expression,the exterior differential method was presented.Furthermore,the properties of the mid-facets of a simplex analogous to median lines of a triangle(such as for all mid-facets of a simplex,there exists another simplex such that its edge-lengths equal to these mid-facets area respectively,and all of the mid-facets of a simplex have a common point)were proved.Finally,by applying the analytic expression,a number of inequalities which combine edge-lengths,circumradius,median line,bisection area and facet area with the mid-facet area for a simplex were established.

  8. Preamble to marine microbiology: Facets and opportunities

    Digital Repository Service at National Institute of Oceanography (India)

    Ramaiah, N.

    The book titled 'Marine Microbiology: Facets & Opportunities' is an attempt to bring together some facets of marine microbiology as have been made out by many contemporaries in particular from the tropical marine regions. There are 18 contributed...

  9. Lumbar facet injection for the treatment of chronic piriformis myofascial pain syndrome: 52 case studies.

    Science.gov (United States)

    Huang, Jen-Ting; Chen, Han-Yu; Hong, Chang-Zern; Lin, Ming-Ta; Chou, Li-Wei; Chen, Hsin-Shui; Tsai, Chien-Tsung; Chang, Wen-Dien

    2014-01-01

    The aim of this study was to demonstrate the effectiveness of lumbar facet joint injection for piriformis myofascial pain syndrome. Fifty-two patients with chronic myofascial pain in the piriformis muscle each received a lumbar facet injection into the ipsilateral L5-S1 facet joint region, using the multiple insertion technique. Subjective pain intensity, trunk extension range, and lumbar facet signs were measured before, immediately after, and 2 weeks after injection. Thirty-six patients received follow-up for 6 months. Immediately after the injection, 27 patients (51.9%) had complete pain subsidence, 19 patients (36.5%) had pain reduction to a tolerable level, and only 6 patients (11.5%) had no pain relief to a tolerable level. Mean pain intensity was reduced from 7.4±0.9 to 1.6±2.1 after injection (Pmyofascial pain syndrome. If this pain is related to lumbar facet lesions, lumbar facet joint injection can immediately suppress piriformis myofascial pain symptoms. This effectiveness may last for at least 6 months in most patients. This study further supports the importance of eliminating the underlying etiological lesion for complete and effective relief of myofascial pain syndrome.

  10. Juxta-facet cysts: MR imaging; Juxtafacettenzysten: Magnetresonanztomographische Diagnostik

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, T.; Daschner, H. [Radiologische Gemeinschaftspraxis, Salewahaus, Augsburg (Germany); Lensch, T. [Radiologische Praxis am Krankenhaus Friedberg (Germany)

    2001-12-01

    The term juxta-facet cyst summarizes synovial cysts, arising from degenerated facet joints and ganglion cysts, developing from mucinous degeneration of periarticular connective tissue. Most juxta-facet cysts are observed at the L4/5 level, which generally has the most motion within the lumbar spine. In this retrospective study 31 juxta-facet cysts in 28 patients were detected within 2898 lumbar MRI studies over a 2-year period (frequency 1%). 24 patients complained of back and lower extremity pain, the other 4 patients had unilateral back pain. In 7 cases radicular symptoms were observed, in 6 patients a neurogenic claudication. In 78% of the patients juxta-facet cysts were responsible for clinical symptoms. MRI is the diagnostic imaging technique of choice due to a high sensitivity. The juxta-facet cysts were located extradural, laterally to the thecal sack and adjacent to a degenerated facet joint. In all but one cases the cysts showed a signal intensity equivalent to cerebrospinal fluid. T2-weighted pulse sequences in sagittal orientation were very useful in delineating the hypointense cyst wall. In 1 patient with acute radicular pain MRI demonstrated a subacute hemorrhage within a juxta-facet cyst. Calcifications and gas-filled cysts can be missed with MRI, but will be demonstrated by computed tomography. 45% of the juxta-facet cysts showed an enhancement of the cyst wall after injection of Gd-DTPA. Spontaneous reduction or resolution of the cyst may occur during rest. Injection of corticosteroids into the corresponding facet joint may reduce the inflammatory process and resolve the symptoms in up to 70%. Surgical resection of the cyst is indicated in case of intractable pain and significant neurologic deficit and generally produces good relief from radicular symptoms. (orig.) [German] Der Begriff Juxtafacettenzyste subsumiert Synovialzysten, die von degenerativ veraenderten Intervertebralgelenken ausgehen, und Ganglionzysten, die durch mukoide Degeneration von

  11. Bilateral locked facets in the thoracic spine

    NARCIS (Netherlands)

    M.H.A. Willems; Braakman, R. (Reinder); B. van Linge (Bert)

    1984-01-01

    textabstractTwo cases of traumatic bilateral locked facets in the thoracic spine are reported. Both patients had only minor neurological signs. They both made a full neurological recovery after surgical reduction of the locked facets. Bilateral locked facets are very uncommon in the thoracic spine.

  12. Cervical facet dislocation adjacent to the fused motion segment.

    Science.gov (United States)

    Yokoyama, Kunio; Kawanishi, Masahiro; Yamada, Makoto; Tanaka, Hidekazu; Ito, Yutaka; Kuroiwa, Toshihiko

    2016-01-01

    This study reports on a case that forces re-examination of merits and demerits of anterior cervical fusion. A 79-year-old male was brought to the emergency room (ER) of our hospital after he fell and struck the occipital region of his head following excessive alcohol consumption. Four years prior, he had undergone anterior cervical discectomy and fusion of C5/6 and a magnetic resonance imaging (MRI) performed 3 years after this surgery indicated that he was suffering from degeneration of C6/7 intervertebral discs. After arriving at the ER, he presented motor impairment at level C7 and lower of manual muscle testing grade 1 as well as moderate loss of physical sensation from the trunk and peripheries of both upper limbs to the peripheries of both lower limbs (Frankel B). Cervical computed tomography (CT) indicated anterior dislocation of C6/7, and MRI indicated severe spinal cord edema. We performed manipulative reduction of C6/7 with the patient under general anesthesia. Next, we performed laminectomy on C5-T1 and posterior fusion on C6/7. Postoperative CT indicated that cervical alignment had improved, and MRI indicated that the spinal cord edema observed prior to surgery had been mitigated. Three months after surgery, motor function and sensory impairment of the lower limbs had improved, and the patient was ambulatory upon discharge from the hospital (Frankel D). In the present case, although C5 and 6 were rigidly fused, degeneration of the C6/7 intervertebral disc occurred and stability was compromised. As a result, even slight trauma placed a severe dynamic burden on the facet joint of C6/7, which led to dislocation.

  13. Cervical facet dislocation adjacent to the fused motion segment

    Directory of Open Access Journals (Sweden)

    Kunio Yokoyama

    2016-01-01

    Full Text Available This study reports on a case that forces re-examination of merits and demerits of anterior cervical fusion. A 79-year-old male was brought to the emergency room (ER of our hospital after he fell and struck the occipital region of his head following excessive alcohol consumption. Four years prior, he had undergone anterior cervical discectomy and fusion of C5/6 and a magnetic resonance imaging (MRI performed 3 years after this surgery indicated that he was suffering from degeneration of C6/7 intervertebral discs. After arriving at the ER, he presented motor impairment at level C7 and lower of manual muscle testing grade 1 as well as moderate loss of physical sensation from the trunk and peripheries of both upper limbs to the peripheries of both lower limbs (Frankel B. Cervical computed tomography (CT indicated anterior dislocation of C6/7, and MRI indicated severe spinal cord edema. We performed manipulative reduction of C6/7 with the patient under general anesthesia. Next, we performed laminectomy on C5-T1 and posterior fusion on C6/7. Postoperative CT indicated that cervical alignment had improved, and MRI indicated that the spinal cord edema observed prior to surgery had been mitigated. Three months after surgery, motor function and sensory impairment of the lower limbs had improved, and the patient was ambulatory upon discharge from the hospital (Frankel D. In the present case, although C5 and 6 were rigidly fused, degeneration of the C6/7 intervertebral disc occurred and stability was compromised. As a result, even slight trauma placed a severe dynamic burden on the facet joint of C6/7, which led to dislocation.

  14. Slamming Testing of Facetted Bottom

    Science.gov (United States)

    2013-11-26

    Technical Report DATES COVERED (From - To) 01 May 2010-31 Aug2013 4. TITLE AND SUBTITLE Slamming Testing of Facetted Bottom 5a. CONTRACT NUMBER...of fast craft are due to slamming , or hydrodynamic impact. A 9 meter long steel / composite hybrid slamming load test facility has been employed for...the purpose of furthering understanding of the slamming phenomenon. This craft is heavily instrumented with strain gages, accelerometers, cameras, an

  15. Design of a lattice-based faceted classification system

    Science.gov (United States)

    Eichmann, David A.; Atkins, John

    1992-01-01

    We describe a software reuse architecture supporting component retrieval by facet classes. The facets are organized into a lattice of facet sets and facet n-tuples. The query mechanism supports precise retrieval and flexible browsing.

  16. Lower extremity extension force and electromyography properties as a function of knee angle and their relation to joint torques: implications for strength diagnostics.

    Science.gov (United States)

    Hahn, Daniel

    2011-06-01

    The purpose of this study was to evaluate whether and how isometric multijoint leg extension strength can be used to assess athletes' muscular capability within the scope of strength diagnosis. External reaction forces (Fext) and kinematics were measured (n = 18) during maximal isometric contractions in a seated leg press at 8 distinct joint angle configurations ranging from 30 to 100° knee flexion. In addition, muscle activation of rectus femoris, vastus medialis, biceps femoris c.l., gastrocnemius medialis, and tibialis anterior was obtained using surface electromyography (EMG). Joint torques for hip, knee, and ankle joints were computed by inverse dynamics. The results showed that unilateral Fext decreased significantly from 3,369 ± 575 N at 30° knee flexion to 1,015 ± 152 N at 100° knee flexion. Despite maximum voluntary effort, excitation of all muscles as measured by EMG root mean square changed with knee flexion angles. Moreover, correlations showed that above-average Fext at low knee flexion is not necessarily associated with above-average Fext at great knee flexion and vice versa. Similarly, it is not possible to deduce high joint torques from high Fext just as above-average joint torques in 1 joint do not signify above-average torques in another joint. From these findings, it is concluded that an evaluation of muscular capability by means of Fext as measured for multijoint leg extension is strongly limited. As practical recommendation, we suggest analyzing multijoint leg extension strength at 3 distinct knee flexion angles or at discipline-specific joint angles. In addition, a careful evaluation of muscular capacity based on measured Fext can be done for knee flexion angles ≥ 80°. For further and detailed analysis of single muscle groups, the use of inverse dynamic modeling is recommended.

  17. 美军军官联合资格认证制度评析%Comment On Officer Joint Qualification System of US Armed Forces

    Institute of Scientific and Technical Information of China (English)

    李现平

    2012-01-01

    Since October 1,2007 US armed forces have put onto practice new joint officer management system: Officer Joint Qualification System. The new management system established four levels of joint qualification from bottom to top for all officers including reserve component. If an officer has achieved the qualification level Ⅲ, he/she will obtain the designation "joint qualified officer" that replaces previous "joint specialty officer". It is an important reform of joint officer management system established by Goldwater-Nichols Department of Defense Reorganization Act of 1986. Its aim is to solve increasingly growing contradiction between offering and need of joint officers by improving the flexibility and comprehensiveness of joint officer management.%美军自2007年10月1日起,实行了新的联合军官管理制度——军官联合资格认证制度。面向全体现役和后备役军官,设置由低到高4个联合资格水平等级,军官达到联合资格三级即可获得“联合资格军官”称号,以此取代之前的“联合专业军官”。它是对1986年《戈德华特一尼科尔斯国防部改组法》所确立的联合军官管理制度的重大调整,目的在于通过提高联合军官管理的灵活性和包容性,解决日益突出的联合军官供需矛盾。

  18. Extending simulation-based acquisition (SBA) to the warfighter with the Air Force Joint Synthetic Battlespace (JSB-AF)

    Science.gov (United States)

    Faye, Phil; Andrew, Emily B.; Lee, Jayson

    2001-09-01

    The Air Force has vectored in a new direction to expand its investment in advanced simulation technologies to improve our readiness, lower costs, and dominate the battles of tomorrow. One of the critical initiatives in this direction is the Joint Synthetic Battlespace (JSB). The JSB will provide an integrated Modeling and Simulation (M&S) environment that brings together analysis, training, and simulations into a coherent whole. The ultimate goal is to develop a JSB simulation capability that will provide a new level of realism in synthetic mission and battlespace environments. This capability will be used to evaluate not only specific systems characteristics but also the associated tactics and procedures. The feature that distinguishes the JSB will be the its ability to realistically represent the real-world mission environment and provide the warfighter with real-time feedback on a system's expected performance. This unprecedented level of realism and response will enable the warfighter to evaluate mission effectiveness and conduct course of action analyses. At the same time, the JSB will increase the acquisition community's ability to build or modify systems to meet users' needs and expectations by making the warfighter the focus and direct participant in the acquisition process. As a detailed engineering and trades tool, the JSB will provide a completely scaleable environment for controlled executions of experiments to support analyses that require repeatability and controlled variations in the simulated environment. The government will also be able to ensure the configuration, control, and consistency of the JSB environment, while the users will develop their own plans and scenarios for their analyses. This will provide a standardized synthetic environment for acquisition programs that can be used as either a distributed or stand-alone application.

  19. An evaluation of force-based design vs. direct displacement-based design of jointed precast post-tensioned wall systems

    Institute of Scientific and Technical Information of China (English)

    M. Ataur Rahman; Sri Sritharan

    2006-01-01

    The unique features of jointed post-tensioned wall systems, which include minimum structural damage and re-centering capability when subjected to earthquake lateral loads, are the result of using unbonded post-tensioning to attach the walls to the foundation, along with employing energy dissipating shear connectors between the walls. Using acceptance criteria defined in terms of inter-story drift, residual drift, and floor acceleration, this study presents a multiplelevel performance-based seismic evaluation of two five-story unbonded post-tensioned jointed precast wall systems. The design and analysis of these two wall systems, established as the direct displacement-based and force-based solutions for a prototype building used in the PREcast Seismic Structural Systems (PRESSS) program, were performed at 60% scale so that the analysis model could be validated using the PRESSS test data. Both buildings satisfied the performance criteria at four levels of earthquake motions although the design base shear of the direct displacement-based jointed wall system was 50%of that demanded by the force-based design method. The study also investigated the feasibility of controlling the maximum transient inter-story drift in a jointed wall system by increasing the number of energy dissipating shear connectors between the walls but without significantly affecting its re-centering capability.

  20. The clinical aspects of the acute facet syndrome

    DEFF Research Database (Denmark)

    Hestbaek, Lise; Kongsted, Alice; Jensen, Tue Secher;

    2009-01-01

    group of chiropractic practitioners was seen to be a useful contribution. METHODS: During the annual congress of The European Chiropractors Union (ECU) in 2008, the authors conducted a workshop involving volunteer chiropractors. Topics were decided upon in advance, and the participants were asked...... of four topics relating to the presentation of pain: 1. location, 2. severity, 3. aggravating factors, and 4. relieving factors. Second, the groups were asked to agree on three orthopaedic and three chiropractic tests that would aid in diagnosing pain from the facet joints. Finally, they were asked...... to agree on the number, frequency and duration of chiropractic treatment. RESULTS: Thirty-four chiropractors from nine European countries participated. They described the characteristics of an acute, uncomplicated facet syndrome as follows: local, ipsilateral pain, occasionally extending into the thigh...

  1. Medial knee joint contact force in the intact limb during walking in recently ambulatory service members with unilateral limb loss: a cross-sectional study

    Directory of Open Access Journals (Sweden)

    Ross H. Miller

    2017-02-01

    Full Text Available Background Individuals with unilateral lower limb amputation have a high risk of developing knee osteoarthritis (OA in their intact limb as they age. This risk may be related to joint loading experienced earlier in life. We hypothesized that loading during walking would be greater in the intact limb of young US military service members with limb loss than in controls with no limb loss. Methods Cross-sectional instrumented gait analysis at self-selected walking speeds with a limb loss group (N = 10, age 27 ± 5 years, 170 ± 36 days since last surgery including five service members with transtibial limb loss and five with transfemoral limb loss, all walking independently with their first prosthesis for approximately two months. Controls (N = 10, age 30 ± 4 years were service members with no overt demographical risk factors for knee OA. 3D inverse dynamics modeling was performed to calculate joint moments and medial knee joint contact forces (JCF were calculated using a reduction-based musculoskeletal modeling method and expressed relative to body weight (BW. Results Peak JCF and maximum JCF loading rate were significantly greater in limb loss (184% BW, 2,469% BW/s vs. controls (157% BW, 1,985% BW/s, with large effect sizes. Results were robust to probabilistic perturbations to the knee model parameters. Discussion Assuming these data are reflective of joint loading experienced in daily life, they support a “mechanical overloading” hypothesis for the risk of developing knee OA in the intact limb of limb loss subjects. Examination of the evolution of gait mechanics, joint loading, and joint health over time, as well as interventions to reduce load or strengthen the ability of the joint to withstand loads, is warranted.

  2. Clinical Observation on the Treatment of Lumbar Facet Joint Disorders with Three-Dimensional Reduction Method Combined with Lumbar Lateral Recess Injection of Xiangdan and Huangqiinjecta%腰椎三维复位法配合侧隐窝注射香丹、黄芪注射液治疗腰椎小关节紊乱疗效观察

    Institute of Scientific and Technical Information of China (English)

    丘宏龙; 陈海鹏; 林桦楠; 陈凯

    2014-01-01

    Objective:To observe the clinical effects of treating 34 cases of lumbarfacet joint disorders with three-dimensional reduction method combined with lumbar lateral recessinjection ofXiang-dan andHuangqi injecta.Methods:68 cases of lumbar facet joint disorders were randomly divided into a treatment group and a control group,34 cases in each group.The control group was treated with three-dimensional reduction method,for manipulation therapy once a day,while the treatment group was treated with lumbar lateral recess injec-tion ofXiangdanandHuangqi injecta on the ifrst,fourth,and seventh days based on the treatment of the control group. The clinical observation of the two groups were made on the tenth day.Results:In the treatment group,10 cases were cured,20 cases were markedly effective,4 cases were ineffective,the efficiency being 88.24%;while in the control group,6 cases were cured,16 cases were markedly effective,12 cases were ineffective,the efifciency being 64.71%.The difference between the two groups was statistically significant(P< 0.01).The PRI,VAS and PPI scores of the treatment group were significantly lower than those of the control group,the difference being statistically significant(P< 0.01).Conclusion:The effect of the three-dimensional reduction method combined with lumbar lateral recess injection is obvious in the treatment of lumbar facet joint disorders,worthy of being clinically promoted.%目的:观察腰椎三维复位法配合侧隐窝注射香丹、黄芪注射液治疗腰椎小关节紊乱的临床疗效。方法:将68例腰椎小关节紊乱患者随机分为治疗组和对照组,每组34例。对照组予腰椎三维复位法治疗,每日1次;治疗组在对照组治疗基础上,于治疗的第1,4,7天行香丹、黄芪注射液腰椎侧隐窝注射,两组均于第10天观察临床疗效。结果:治疗组治愈10例,显效20例,无效4例,有效率88.24%;对照组治愈6例,显效16例,无效12例,有效率64

  3. Observation of 144 Treatments of Cervical Facet Joints Typo by Cervical Repositioning Plus Fuyang Cans%114例颈椎定点复位法加扶阳罐治疗颈椎小关节微错缝的临床观察

    Institute of Scientific and Technical Information of China (English)

    孙大桥; 冯高基; 王德燕

    2016-01-01

    目的:探讨颈椎定点复位法加扶阳罐治疗颈椎小关节微错缝的临床疗效。方法:114例患者均采用颈椎定点复位法加扶阳罐治疗。具体分四步。手法定位;松解肌肉;颈椎定点旋转复位;扶阳罐理筋温熨。5次一疗程。若还有症状,休息二天后,重复一疗程。结果:治愈率89.47%,总有效率99.12%。结论:此法可纠正颈椎紊乱的关节,缓解痉挛的肌肉,解除神经、血管的刺激和压迫,改善局部血液循环,使颈椎各关节保持相对的稳定。疗效好,安全易行,值得推广。%The paper discusses the cervical repositioning Fu Yang cans clinical effects of cervical facet joints micro wrong treatment. Method: 114 cases of patients were treated by cervical repositioning Fu Yang cans treatment. Specifically in four steps. Positioning techniques, Releasing muscle, cervical rotation reset, Fu Yang Management warm iron bars, 5 times a course of treatment. If there are symptoms, the patient takes two days of rest, and repeats a course. Result: cure rate of 89.47%, the total efficiency of 99.12%. Conclusion: this method corrects cervical joint disorders, relieves muscle spasm, relieves nerves and blood vessels and stimulate the oppression, and improve local blood circulation, making each joint of cervical remained relatively stable. Effective, safe and easy, it is worthy to promotion.

  4. Enhanced crosslimb transfer of force-field learning for dynamics that are identical in extrinsic and joint-based coordinates for both limbs.

    Science.gov (United States)

    Carroll, Timothy J; de Rugy, Aymar; Howard, Ian S; Ingram, James N; Wolpert, Daniel M

    2016-01-01

    Humans are able to adapt their motor commands to make accurate movements in novel sensorimotor environments, such as when wielding tools that alter limb dynamics. However, it is unclear to what extent sensorimotor representations, obtained through experience with one limb, are available to the opposite, untrained limb and in which form they are available. Here, we compared crosslimb transfer of force-field compensation after participants adapted to a velocity-dependent curl field, oriented either in the sagittal or the transverse plane. Due to the mirror symmetry of the limbs, the force field had identical effects for both limbs in joint and extrinsic coordinates in the sagittal plane but conflicting joint-based effects in the transverse plane. The degree of force-field compensation exhibited by the opposite arm in probe trials immediately after initial learning was significantly greater after sagittal (26 ± 5%) than transverse plane adaptation (9 ± 4%; P coordinates for the two limbs. The data reveal that neural representations of novel dynamics are only partially available to the opposite limb, since transfer is incomplete even when force-field perturbation is spatially compatible for the two limbs, according to both intrinsic and extrinsic coordinates.

  5. Estimation of the forces acting on the tibiofemoral joint during knee extension exercises performed on an open kinetic chain strength-training machine

    Directory of Open Access Journals (Sweden)

    Jefferson Fagundes Loss

    2008-01-01

    Full Text Available The objectives of this study were to: (1 evaluate the resistive torque of an open kinetic chain strength-training machine for performing knee extensions, and (2 perform an analysis estimating internal forces in the tibiofemoral joint. During a fi rst phase of the study, measurements were taken of the machine under analysis (external forces, and then calculations were performed to estimate forces on the lower limb (internal forces. Equations were defi ned to calculate human force (HF, and the moment of muscular force (MMF. Perpendicular muscular force (MFp and joint force (JFp, axial muscular force (MF” and joint force (JF”, and total muscular force (MF and joint force (JF were all calculated. Five knee angles were analyzed (zero, 30, 45, 60, and 90 degrees. A reduction was observed in HF at higher knee angles, while MF and JF also increased at the same time. HF was always lower than the load selected on the machine, which indicates a reduced overload imposed by the machine. The reduction observed in MFp and JFp at higher knee angles indicates a lower tendency to shear the tibia in relation to the femur. At the same time, there was an increase in JF” due to higher MF”. The biomechanical model proposed in this study has shown itself adequate for the day-to-day needs of professionals who supervise orient strength training. resumo Os objetivos do presente estudo foram: (1 avaliar o torque de resistência (TR de uma máquina de musculação para a realização do exercício de extensão dos joelhos em cadeia cinética aberta e (2 realizar um ensaio teórico a partir do comportamento do TR com o intuito de estimar as forças internas na articulação tíbio-femoral. O estudo foi realizado em dois momentos: (1 medições da máquina utilizada e (2 estimativa das forças externas (na máquina e internas (no membro inferior. Foram utilizadas equações baseadas em um modelo mecânico bi-dimensional para o cálculo das componentes perpendiculares

  6. Avaliação clínica da infiltração facetaria no tratamento da dor lombar crônica por síndrome facetaria: estudo prospectivo Evaluación clínica de la infiltración de las facetas en el tratamiento del dolor crónico de espalda baja por el síndrome de faceta síndrome: estudio prospectivo Clinical evaluation of the lumbar facet joint blocks in treatment of chronic low back pain: a prospective study

    Directory of Open Access Journals (Sweden)

    Thiago Miller Santana Silva

    2011-01-01

    Full Text Available OBJETIVO: Avaliar os resultados do bloqueio facetário lombar com anestésico local e corticóide em pacientes com lombalgia crônica por síndrome facetária. MÉTODOS: Realizou-se um estudo prospectivo em 30 pacientes com lombalgia crônica por síndrome facetária, os quais foram submetidos à infiltração facetária com bupivacaína a 0,25% e acetato de metilpredinisolona sob controle radioscópico, e foram seguidos e avaliados seguindo as escalas Visual Analógica da Dor, Oswestry Disability Index e os Critérios de MacNab nos quais 17 foram do sexo feminino e 13 do sexo masculino. RESULTADOS: Foi observada diminuição significativa (pOBJETIVO: Evaluar los resultados del bloqueo facetario lumbar, con anestésico local y corticoide, en pacientes con dorsalgia crónica por síndrome facetario. MÉTODOS: Se realizó un estudio prospectivo en 30 pacientes, 17 del sexo femenino y 13 del sexo masculino, con dorsalgia crónica por síndrome facetario, quienes fueron sometidos a la infiltración facetaria con bupivacaína a 0,25% y acetato de metilpredinisolona bajo control radioscópico, y fueron acompañados y evaluados siguiendo las escalas Visual Analógica del Dolor, Oswestry Disability Index y los Criterios de MacNab. RESULTADOS: Se observó una disminución significativa (pOBJECTIVE: To evaluate the lumbar facet block with local anesthetics and corticosteroids in patients with chronic low back pain of facet joint origin. METHODS: We conducted a prospective study on 30 patients with chronic low back pain in facet syndrome who underwent facet infiltration with bupivacaine 0.25% and methylprednisolone acetate under radioscopic control; the subjects were followed and evaluated following the Visual Analogue Scale of Pain , Oswestry Disability Index and MacNab criteria; 17 of them were female and 13 male. RESULTS: Reduction of pain was found by Visual Analogue Scale significant (p <0.05. We obtained 73.3% of satisfactory results in the first

  7. Treatment of cervical dislocation with locked facets

    Institute of Scientific and Technical Information of China (English)

    YU Ze-sheng; James J.Yue; WEI Feng; LIU Zhong-jun; CHEN Zhong-qiang; DANG Geng-ting

    2007-01-01

    Background Lower cervical dislocation with locked facets is common in cervical injury. The locked facets include unilateral and bilateral types. Different successful closed reduction rates has been achieved between unilateral and bilateral types by using rapid skull traction, which was commonly used to reduce the cervical dislocation. It is important to investigate a suitable management specific to patients with different types of cervical locked facets.Methods A total of 38 patients with cervical dislocation with locked facet due to cervical injury treated by rapid skull traction and operation from 1988 to 2005 were reviewed. Rapid skull traction was used in all the patients. Successful closed reduction rate was 88.0% in patients with bilateral cervical locked facets and that was 15.4% in those with unilateral cervical locked facets. These data were then statistically compared by Chi-square test. Patients who were reduced successfully underwent anterior cervical discectomy and fusion at the injured level, and those who failed in closed reduction received posterior open reduction and fixation.Results In this series, there was statistically significant difference (P<0.05) in the rate of successful closed skull traction reduction between unilateral and bilateral locked facets dislocation. Unilateral cervical locked facets dislocation was not easily reduced by skull traction which was suitable for reduction of bilateral cervical locked facets dislocation. However,unilateral cervical locked facets dislocation can be reduced by posterior open reduction.Conclusions Unilateral cervical locked facets dislocation should be treated immediately with posterior open reduction and instrumentation. Bilateral cervical locked facets dislocation can be reduced by rapid skull traction firstly and anterior cervical discectomy and interbody fusion later.

  8. Two Facets of Narcissism and Compulsive Buying

    National Research Council Canada - National Science Library

    Sunghwan Yi; Roisin O'Connor

    2015-01-01

      Although recent psychology research indicates that overt and covert narcissism are distinct facets of narcissism, the association between covert narcissism and compulsive buying has not been recognized...

  9. Observations on the Efficacy of Warm Needling plus Palm Pressing Spine Reduction Technique in Treating Postpartum Thoracic Facet Joint Disorder%针灸配合脊柱复位手法治疗产后胸椎小关节紊乱疗效观察

    Institute of Scientific and Technical Information of China (English)

    卓缘圆; 吴家满

    2015-01-01

    Objective To investigate the clinical efficacy of warm needling plus palm pressing spine reduction technique in treating postpartum thoracic facet joint disorder.Methods Forty patients with postpartum thoracic facet joint disorder were randomly allocated to treatment and control groups, 20 cases each. The treatment group received warm needling plus palm pressing spine reduction technique and the control group, warm needling alone. The numeric pain rating scale (NPRS) score, the Oswestry Disability Index (ODI) score and the Quality of Life Scale score were recorded in the two groups before and after treatment and the clinical therapeutic effects were compared between the two groups.Results The total efficacy rate was 95.0% in the treatment group and 75.0% in the control group; there was a statistically significant difference between the two groups (P<0.01). There were statistically significant pre-/post-treatment differences in the NPRS score and the ODI score in the treatment group (P<0.01). There was a statistically significant pre-/post-treatment difference in the NPRS score in the control group (P<0.01). There were statistically significant post-treatment differences in the NPRS score and the ODI score between the treatment and control groups (P<0.01,P<0.05). There were statistically significant pre-/post-treatment differences in the SF-36 PF, RP, BP, VT, SF and MH scores in the treatment group (P<0.01,P<0.05). There were statistically significant pre-/post-treatment differences in the SF-36 PF BP, SF and MH scores in the control group (P<0.01,P<0.05).Conclusion Warm needling plus palm pressing spine reduction technique is an effective way to treat postpartum thoracic facet joint disorder.%目的:观察针灸配合掌按脊柱复位手法治疗产后胸椎小关节紊乱的临床疗效。方法将40例产后胸椎小关节紊乱患者随机分为治疗组和对照组,每组20例。治疗组采用针灸配合掌按脊柱复位手法治疗,对照组采用单纯

  10. Different facets of market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    2009-01-01

    it was found that there was a marketplace-determined 'gravitational centre effect' that limited the political market orientation of the manifesto, whilst this was less pronounced in Germany. This leads to the hypothesis that certain aspects of political market orientation may be mediated by structural......In this study we employ the concept of political market orientation to better understand how the main political parties in the UK and Germany relate to other stakeholders in the political sphere through an exploratory content analysis of their core election offering, the manifesto. This study has...... two aims: firstly, we will discuss the different facets of the market orientation of the main UK and German parties in their respective 2005 General Elections through an exploratory content analysis, and secondly, we will compare characteristics of market orientation between the two countries. Whilst...

  11. Different facets of market orientation

    DEFF Research Database (Denmark)

    Ormrod, Robert P.; Henneberg, Stephan C.

    2009-01-01

    In this study we employ the concept of political market orientation to better understand how the main political parties in the UK and Germany relate to other stakeholders in the political sphere through an exploratory content analysis of their core election offering, the manifesto. This study has...... two aims: firstly, we will discuss the different facets of the market orientation of the main UK and German parties in their respective 2005 General Elections through an exploratory content analysis, and secondly, we will compare characteristics of market orientation between the two countries. Whilst...... the UK parties generally exhibited similar levels of market orientation on each of the relevant construct dimensions, the German parties had more distinct profiles; thus the applied dimensions of political market orientation show discriminatory power within and across electoral systems. In the UK...

  12. A comprehensive three-dimensional dynamic model of the human head and trunk for estimating lumbar and cervical joint torques and forces from upper body kinematics.

    Science.gov (United States)

    Vette, Albert H; Yoshida, Takashi; Thrasher, T Adam; Masani, K; Popovic, Milos R

    2012-06-01

    Linked-segment representations of human body dynamics have been used extensively in biomechanics, ergonomics, and rehabilitation research to systemize thinking, make predictions, and suggest novel experiments. In the scope of upper body biomechanics, these models play an even more essential role as the human spine dynamics are difficult to study in vivo. No study exists to date, however, that specifically disseminates the technical details of a comprehensive three-dimensional model of the upper body for the purpose of estimating spinal joint torques and forces for a wide range of scenarios. Consequently, researchers are still bound to develop and implement their own models. Therefore, the objective of this study was to design a dynamic model of the upper body that can comprehensively estimate spinal joint torques and forces from upper body kinematics. The proposed three-dimensional model focuses on the actions of the lumbar and cervical vertebrae and consists of five lumbar segments (L1 to L5), the thorax, six cervical segments (C2 to C7), and the head. Additionally, the model: (1) is flexible regarding the kinematic nature of the spinal joints (free, constrained, or fixed); (2) incorporates all geometric and mass-inertia parameters from a single, high-resolution source; and (3) can be feasibly implemented via different inverse dynamics formulations. To demonstrate its practicality, the model was finally employed to estimate the lumbar and cervical joint torques during perturbed sitting using experimental motion data. Considering the growing importance of mathematical predictions, the developed model should become an important resource for researchers in different fields. Copyright © 2011 IPEM. Published by Elsevier Ltd. All rights reserved.

  13. Effective and Efficient Multi-Facet Web Image Annotation

    Institute of Scientific and Technical Information of China (English)

    Jia Chen; Yi-He Zhu; Hao-Fen Wang; Wei Jin; Yong Yu

    2012-01-01

    The vast amount of images available on the Web request for an effective and efficient search service to help users find relevant images.The prevalent way is to provide a keyword interface for users to submit queries.However,the amount of images without any tags or annotations are beyond the reach of manual efforts.To overcome this,automatic image annotation techniques emerge,which are generally a process of selecting a suitable set of tags for a given image without user intervention.However,there are three main challenges with respect to Web-scale image annotation:scalability,noiseresistance and diversity.Scalability has a twofold meaning:first an automatic image annotation system should be scalable with respect to billions of images on the Web; second it should be able to automatically identify several relevant tags among a huge tag set for a given image within seconds or even faster.Noise-resistance means that the system should be robust enough against typos and ambiguous terms used in tags.Diversity represents that image content may include both scenes and objects,which are further described by multiple different image features constituting different facets in annotation.In this paper,we propose a unified framework to tackle the above three challenges for automatic Web image annotation.It mainly involves two components:tag candidate retrieval and multi-facet annotation.In the former content-based indexing and concept-based codebook are leveraged to solve scalability and noise-resistance issues.In the latter the joint feature map has been designed to describe different facets of tags in annotations and the relations between these facets.Tag graph is adopted to represent tags in the entire annotation and the structured learning technique is employed to construct a learning model on top of the tag graph based on the generated joint feature map.Millions of images from Flickr are used in our evaluation.Experimental results show that we have achieved 33% performance

  14. The Future of Amphibious Operations: Shaping the Expeditionary Strike Group to Fight in the Joint Task Force

    Science.gov (United States)

    2010-02-01

    Maintenance Unit 202, Air Force Civil Engineering Squadron V’s Prime Base Engineer Emergency Force, medical personnel from the armed forces of...Admiral Jerauld Wright--Warrior Among Diplomats (Manhattan, Kan: Sunflower University Press, 2001), 222-223. 42 which created confusion for...Knopf, 1984. 67 Key, David M. Admiral Jerauld Wright--Warrior Among Diplomats. Manhattan, Kan: Sunflower University Press, 2001. Kirk, Amy

  15. Morphometry of the lumbar zygapophyseal facet capsule and cartilage with special reference to degenerative osteoarthritic changes: an anatomical study using fresh cadavers of elderly Japanese and Korean subjects.

    Science.gov (United States)

    Tanno, Iwao; Murakami, Gen; Oguma, Hiroshi; Sato, Shu-Ichi; Lee, U-Young; Han, Seung-Ho; Yamashita, Toshihiko

    2004-01-01

    Morphometric data were obtained from fresh cadaver dissections, and observations of degenerative changes in the joint cartilage (DCs) were analyzed to determine whether the morphometric parameters of the lumbar zygapophyseal joint capsule varied according to the presence and severity of DCs. There have been no previous morphometric studies of the facet capsule that describe age-related DCs. Using 23 fresh osteoligamentous lumbar spines from donated cadavers, we performed morphometric investigations of the surface areas of the joints and their capsules and measured the capsular thickness. We hypothesized that the ratio of the inner capsular area to the joint surface area for each facet (the capsule/facet index) could serve as an index showing a functional aspect of a large or small capsule. Our results showed that the joint surface area increased significantly with increasing severity of DCs, according to Grogan's classification. Facets with advanced DCs tended to have a small inner capsular surface. The capsule/facet index generally correlated positively with capsular thickness, especially the dorsal portion; however, this was not true for the ventral portion. The index also correlated negatively with DC progression. Thus, lumbar facet DCs were strongly linked to reconstructive alterations in capsular size, thickness, and looseness. The occurrence and progression of DCs narrowed the joint capsule, especially the dorsal portion, and this seemed to decrease the potential looseness of the joint. Conversely, these capsular alterations seemed to accelerate DC progression. A negative adaptation cycle seemed to occur.

  16. Partitioning of knee joint internal forces in gait is dictated by the knee adduction angle and not by the knee adduction moment.

    Science.gov (United States)

    Adouni, M; Shirazi-Adl, A

    2014-05-01

    Medial knee osteoarthritis is a debilitating disease. Surgical and conservative interventions are performed to manage its progression via reduction of load on the medial compartment or equivalently its surrogate measure, the external adduction moment. However, some studies have questioned a correlation between the medial load and adduction moment. Using a musculoskeletal model of the lower extremity driven by kinematics-kinetics of asymptomatic subjects at gait midstance, we aim here to quantify the relative effects of changes in the knee adduction angle versus changes in the adduction moment on the joint response and medial/lateral load partitioning. The reference adduction rotation of 1.6° is altered by ±1.5° to 3.1° and 0.1° or the knee reference adduction moment of 17Nm is varied by ±50% to 25.5Nm and 8.5Nm. Quadriceps, hamstrings and tibiofemoral contact forces substantially increased as adduction angle dropped and diminished as it increased. The medial/lateral ratio of contact forces slightly altered by changes in the adduction moment but a larger adduction rotation hugely increased this ratio from 8.8 to a 90 while in contrast a smaller adduction rotation yielded a more uniform distribution. If the aim in an intervention is to diminish the medial contact force and medial/lateral load ratio, a drop of 1.5° in adduction angle is much more effective (causing respectively 12% and 80% decreases) than a reduction of 50% in the adduction moment (causing respectively 4% and 13% decreases). Substantial role of changes in adduction angle is due to the associated alterations in joint nonlinear passive resistance. These findings explain the poor correlation between knee adduction moment and tibiofemoral compartment loading during gait suggesting that the internal load partitioning is dictated by the joint adduction angle.

  17. Facet selective etching of Au microcrystallites

    Institute of Scientific and Technical Information of China (English)

    Gangaiah Mettela and Giridhar U. Kulkarni

    2015-01-01

    High-symmetry crystals exhibit isotropic properties. Inducing anisotropy, e.g., by facet selective etching, is considered implausible in face-centered cubic (FCC) metals, particularly gold, which, in addition to being an FCC, is noble. We report for the first time the facet selective etching of Au microcrystals obtained in the form of cuboctahedra and pentagonal rods from the thermolysis of a gold- organic precursor. The selective etching of {111} and {100} facets was achieved using a capping method in which tetraoctylammonium cations selectively cap the {111} facets while Br- ions protect the {100} facets. The exposed facets are oxidized by O2/C1-, yielding a variety of interesting geometries. The facet selective etching of the Au microcrystallites is governed only by the nature of the facets; the geometry of the microcystallite does not appear to play a significant role. The etched surfaces appear rough, but a closer examination reveals well-defined corrugations that are indexable to high hkl values. Such surfaces exhibit enhanced Raman activity.

  18. Boundary management and integration framework for a joint cyber defence capability for military forces: analysis and synthesis from a through-life capability management perspective

    CSIR Research Space (South Africa)

    Roodt, JHS

    2010-04-01

    Full Text Available five JCD domains. As was stated, the model is simplistic to say the least, but was developed to demonstrate the approach. C2W PO IBW Application Layer Information Layer Network Layer Communications LayerEW Other NW IIW Sensor Layer... Management and Integration Framework for a Joint Cyber Defence Capability for Military Forces: Analysis and Synthesis from a Through-Life Capability Management Perspective J H S Roodt 1 , R Oosthuizen 2 , J C Jansen van Vuuren 1 1 Defence Peace...

  19. Facets of the balanced minimal evolution polytope.

    Science.gov (United States)

    Forcey, Stefan; Keefe, Logan; Sands, William

    2016-08-01

    The balanced minimal evolution (BME) method of creating phylogenetic trees can be formulated as a linear programming problem, minimizing an inner product over the vertices of the BME polytope. In this paper we undertake the project of describing the facets of this polytope. We classify and identify the combinatorial structure and geometry (facet inequalities) of all the facets in dimensions up to five, and classify even more facets in all dimensions. A full set of facet inequalities would allow a full implementation of the simplex method for finding the BME tree-although there are reasons to think this an unreachable goal. However, our results provide the crucial first steps for a more likely-to-be-successful program: finding efficient relaxations of the BME polytope.

  20. Search Result Diversification Based on Query Facets

    Institute of Scientific and Technical Information of China (English)

    胡莎; 窦志成; 王晓捷; 继荣

    2015-01-01

    In search engines, different users may search for different information by issuing the same query. To satisfy more users with limited search results, search result diversification re-ranks the results to cover as many user intents as possible. Most existing intent-aware diversification algorithms recognize user intents as subtopics, each of which is usually a word, a phrase, or a piece of description. In this paper, we leverage query facets to understand user intents in diversification, where each facet contains a group of words or phrases that explain an underlying intent of a query. We generate subtopics based on query facets and propose faceted diversification approaches. Experimental results on the public TREC 2009 dataset show that our faceted approaches outperform state-of-the-art diversification models.

  1. Numerical simulation of facet dendrite growth

    Institute of Scientific and Technical Information of China (English)

    CHEN Zhi; CHEN Chang-le; HAO Li-mei

    2008-01-01

    Numerical simulation based on phase field method was performed to describe the solidification of silicon. The effect of anisotropy, undercooling and coupling parameter on dendrite growth shape was investigated. It is indicated that the entire facet dendrite shapes are obtained by using regularized phase field model. Steady state tip velocity of dendrite drives to a fixed value when γ≤0.13. With further increasing the anisotropy value, steady state tip velocity decreases and the size is smaller. With the increase in the undercooling and coupling parameter, crystal grows from facet to facet dendrite. In addition, with increasing coupling parameter, the facet part of facet dendrite decreases gradually, which is in good agreement with Wulff theory.

  2. Hip-joint and abductor-muscle forces adequately represent in vivo loading of a cemented total hip reconstruction.

    NARCIS (Netherlands)

    Stolk, J.; Verdonschot, N.J.J.; Huiskes, R.

    2001-01-01

    Using finite element analyses, we investigated which muscle groups acting around the hip-joint most prominently affected the load distributions in cemented total hip reconstructions with a bonded and debonded femoral stem. The purpose was to determine which muscle groups should be included in pre-cl

  3. Traumatic unilateral lumbosacral jumped facet without fracture in a child - presentation of a safe treatment strategy for a rare injury.

    Science.gov (United States)

    Szentirmai, Oszkar; Seinfeld, Joshua; Beauchamp, Kathryn; Patel, Vikas

    2008-11-10

    The vast majority of pediatric lumbosacral spondylolisthesis have developmental etiology. Of the very rare type of pediatric lumbosacral facet dislocations, there are only three reported cases of a pediatric unilateral jumped facet injury. All of these cases are associated with fracture dislocation of L5-S1. Hyperflexion with rotation is thought to provoke this uncommon type of spine injury.The authors report the first pediatric patient reported in literature to date with a traumatic unilateral jumped facet at the lumbosacral joint without fracture. The presentation, surgical treatment, hospital course, outcome and management options with the review of the literature is summarized.

  4. Quantification of functional brace forces for posterior cruciate ligament injuries on the knee joint: an in vivo investigation.

    Science.gov (United States)

    LaPrade, Robert F; Smith, Sean D; Wilson, Katharine J; Wijdicks, Coen A

    2015-10-01

    Counteracting posterior translation of the tibia with an anterior force on the posterior proximal tibia has been demonstrated clinically to improve posterior knee laxity following posterior cruciate ligament (PCL) injury. This study quantified forces applied to the posterior proximal tibia by two knee braces designed for treatment of PCL injuries. The forces applied by two knee braces to the posterior proximal tibia and in vivo three-dimensional knee kinematics of six adult, male, healthy volunteer subjects (mean ± standard deviation: height, 182.5 ± 5.2 cm; body mass, 83.2 ± 9.3 kg; body mass index, 24.9 ± 1.5 kg/m(2); age, 25.8 ± 2.9 years) were measured using a custom pressure mapping technique and traditional surface marker motion capture techniques, while subjects performed three functional activities. The activities included seated unloaded knee flexion, squatting, and stair descent in a new generation dynamic force (DF) PCL brace and a static force (SF) PCL brace. During unloaded flexion at the lowest force level setting, the force applied by the DF brace increased as a function of flexion angle (slope = 0.7 N/°; p knee laxity following PCL injury. II.

  5. Research on the Personal Safety Work for Female Nurs-ing Interns through Joint Forces%形成合力做好护理专业实习女生人身安全工作研究

    Institute of Scientific and Technical Information of China (English)

    万英; 冉丽; 李志强; 姚本丽

    2016-01-01

    从恩格斯的“历史合力论”原理出发,引申出护理专业实习女生人身安全工作需要学校、实习单位、家长、实习生、其他力量、辅导员等形成合力,并且减少合力中的消极因素,确保护理专业实习女生人身安全得到有效保障。%According to Engels' history with joint forces theory, this paper extends the meaning that the personal safety work for female nursing interns needs the joint forces of the college, prac-tice sites, parents, interns themselves, counselors and other forces, and negative factors in the joint forces should be reduced, in order to effectively ensure the personal safety of female nursing interns.

  6. Joint Interagency Task Force-South: The Best Known, Least Understood Interagency Success (INSS Strategic Perspectives, Number 5, June 2011)

    Science.gov (United States)

    2011-06-01

    searching or arresting civil - ians), but it allowed the military to provide technical assistance to law enforcement officers, such as providing...involving a foreign nation. For example, a long-running joint operation with Guatemala, “ Mayan Jaguar,” was ruined when a go-fast tracked by JIATF...doc=GetTRDoc.pdf>; Derek S. Wessman, “Defense Support to Civil Authorities: Critical Capability or Vulnerability? Op- timizing DOD’s Domestic Range

  7. Method for partially coating laser diode facets

    Science.gov (United States)

    Dholakia, Anil R. (Inventor)

    1990-01-01

    Bars of integral laser diode devices cleaved from a wafer are placed with their p regions abutting and n regions abutting. A thin BeCu mask having alternate openings and strips of the same width as the end facets is used to mask the n region interfaces so that multiple bars can be partially coated over their exposed p regions with a reflective or partial reflective coating. The partial coating permits identification of the emitting facet from the fully coated back facet during a later device mounting procedure.

  8. 共同侵权中原因力与相当因果关系分析%Analysis of Casual Force and Equivalent Relationship in Joint Tort

    Institute of Scientific and Technical Information of China (English)

    蔺小涵

    2015-01-01

    侵权法中的因果关系一直以来都是侵权责任确定的重要条件,通过对加害人和受害人之间因果关系的准确界定,可以使受害人的损失得到有效合理的保护,也让加害人的责任得到合理的限制。同时,原因力也是共同侵权中的重要组成部分,对于原因力大小的判断可以合理的界定加害人所担负的责任从而保护受害人的利益。共同侵权中关于因果关系的准确认定是进行原因力大小分析的重要前提,其中相当因果关系的认定对于正确判断共同侵权中的因果关系起着极为重要的判断作用,所以只有共同侵权构成要件统一完备,才能真正保护人们的合法利益,满足社会道德和伦理的需求,维护人们自由意志的立法精神。%The cause-and-effect relationship is an important condition in recognizing the tort liability . The loss of victims will get reasonable protection and the liability of offenders will be get reasonable limita-tion through an accurate defining of the casual relationship between offenders and victims .Casual force is an important component in joint tort and the judge on its force will lead to a reasonable defining of offenders'liability so as to protect the interest of the victims .An accurate defining of this relationship in joint tort is an important premise in deciding the force of causes ,in w hich the defining of equivalent forces plays a crit-ical role in making correct judge in joint tort cases .Therefore ,only when the constitutive elements are complete ,can we really protect the legal interest of people ,satisfy the needs of social morality and ethics and maintain the freewill of people in legislative spirit .

  9. 后前入路治疗下颈椎骨折脱位伴双侧关节突绞锁%Decompression via posterior-anterior approach and anterior fixation in treatment of fracture-dislocation of the lower cervical spine with bilateral facet joints dislocation

    Institute of Scientific and Technical Information of China (English)

    李鹏; 雪原; 王沛; 马信龙; 赵华健; 赵晓涛; 卢旭亚

    2011-01-01

    Objective To evaluate the surgical strategy of decompression via posterior-anterior approach and anterior fixation in treatment fracture-dislocation of the lower cervical spine with bilateral facet joints dislocation. Methods This study retrospectively reviewed 37 cases of lower cervical spine fracture with bilateral joints dislocation. There were 21 males and 16 females with an average age of 42 years (19-58). Distraction-flexion stage 3(DFS 3) were found in 24 cases and DFS 4 in 13 cases. All the cases were diagnosed by X-ray, CT and MRI and confirmed during the surgery. Decompression via posterior-anterior approach and anterior fixation had been adapted as the surgical strategy. The NASCIS and IMSOP standard were applied to definite the level of cervical spinal cord injury. The ASIA grading was used for evaluation the spinal cord function and the recovery rate. The X-ray and CT were used to observe reduction and bone fusion. Results The mean operative time was (4.5:±0.5) h, and the mean amount of blood loss was 360 ml (200-500 ml). All the incision healed. The two segments fixation was used in 23 cases, 3 segments fixation in 13 cases, and 4 segments fixation in 1 case. The mean follow-up period was 32 months (16-45 months).Postoperative X-ray and CT showed that bone fusion was achieved in all patients within 4-8 months, without graft displacement, or failure of implants. Spinal cord function did not aggravate, and sensory recovery ranged from 7 to 20 levels (averaged, 12.7). The ASIA grade were improved with an average of one grade. Conclusion To treat fracture-dislocation of the lower cervical spine with bilateral facet joints dislocation, the posterlor-anterior approach and anterior fixation/fusion was benefit to preservation the cervical spinal cord function and reconstruction biomechanical stability of the cervical spine.%目的 探讨后前路减压、前路固定治疗下颈椎骨折脱位伴双侧关节突绞锁的可行性及临床效果.方法 2000

  10. 一期后路保留部分关节突开窗病灶清除短节段椎弓根螺钉内固定治疗腰骶椎结核%ONE-STAGE POSTERIOR RETAINING PART FACET JOINT IN LAMINECTOMY AND DEBRIDEMENT COMBINED WITH SHORT SEGMENTAL PEDICLE SCREW FIXATION FOR LUMBOSACRAL SPINAL TUBERCULOSIS

    Institute of Scientific and Technical Information of China (English)

    陈林; 覃建朴; 敖俊; 廖文波; 蔡玉强

    2016-01-01

    effectiveness of one-stage posterior retaining part facet joint in laminectomy,bone graft and debridement combined with short segmental pedicle screw fixation for lumbosacral spinal tuberculosis.Methods Between January 2010 and December 2014,32 cases of lumbosacral spinal tuberculosis (L4-S1) were treated by one-stage posterior retaining part facet joint in laminectomy,bone graft and debridement combined with short segmental pedicle screw fixation.There were 20 males and 12 females,aged 17-62 years (mean,43 years).The disease duration was 12-48 months (mean,18 months).The involved segments included L5,S1 level in 19 cases and L4.5 level in 13 cases.The effectiveness was evaluated by Oswestry disability index (ODI) and imaging parameters (lumbarsacral angle correction and Bridwel1 classification and CT fusion criteria) after operation.Results The operation was successfully completed in all patients;the average operation time was 180 minutes,and the average intraoperative blood loss was 400 mL.All cases were followed up 12 to 67 months (mean,15.6 months).At last follow-up,common toxic symptom of tuberculosis disappeared,and no internal fixation failure occurred.Neurological function was recovered to normal in 7 patients with neurological symptoms,and American Spinal Injury Association (ASIA) scale was improved to grade E from grade C (2 cases) and grade D (5 cases) before operation.At 1 year and last follow-up,the ODI scores were significantly improved when compared with preoperative score (P<0.05),but no significant difference was found between at 1 year and last follow-up (P>0.05).The lumbarsacral angle was significantly increased at 7 days,1 year and last follow-up when compared with preoperative one (P<0.05),but there was no significant difference between different time points after operation (P>0.05).The bone graft fusion time was 9-24 months (mean,12 months).At 1 year after operation and last follow-up,X-ray Bridwill bone fusion rates were 87.50% (28/32) and 93

  11. Efficacy of a trunk orthosis with joints providing resistive force on low-back load in elderly persons during static standing.

    Science.gov (United States)

    Katsuhira, Junji; Matsudaira, Ko; Yasui, Tadashi; Iijima, Shinno; Ito, Akihiro

    2015-01-01

    Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO) in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force) as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES), left internal abdominal oblique, and right gluteus medius muscles. Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these results were not significant compared to no orthosis. Thorax extension angle and thorax angle on pelvis coordinate system significantly increased while wearing the ORF compared to the other two conditions. ES activity significantly decreased while wearing the ORF compared to the other two conditions. Internal oblique activity was significantly smaller while wearing the LSO than with no orthosis. Center of pressure did not significantly differ among the conditions. The ORF significantly improved trunk alignment and decreased ES activity in healthy

  12. Facet injection trends in the Medicare population and the impact of bundling codes.

    Science.gov (United States)

    Beckworth, William Jeremy; Jiang, Miao; Hemingway, Jennifer; Hughes, Danny; Staggs, Donald

    2016-09-01

    Interventional spine procedures have seen a steady increase in utilization over the last 10 to 20 years. In 2010, the Current Procedural Terminology (CPT) codes for facet injections were bundled with image guidance (fluoroscopic or computed tomography) and limited billing to a maximum of three levels. This was done in part because of increased utilization and to ensure that procedures were done appropriately with image guidance. The study aimed to evaluate if the CPT code changes correlated with a decreased utilization of facet injections. This is a retrospective time series study. The sample was composed of 100% Medicare Part B claims submitted for facet joint injections from 2000 to 2012, as documented in the Centers for Medicare & Medicaid Services (CMS) Physician Supplier Procedure Summary (PSPS) master files. Procedure numbers and trends were the outcome measures. The trends of facet injections were analyzed from 2000 to 2012 using the CMS PSPS master files. The total number of lumbosacral and cervical-thoracic facet injections was noted. Changes over those years were calculated with specific attention to 2010, when CPT were bundled with image guidance and injections were limited to no more than three levels. Also, to account for the growth in the Medicare population, a calculation was done of injections per 100,000 Medicare enrollees. No funding was used for this study. Facet injection utilization increased from 2000 to 2012, with an average growth rate of 11% per year for lumbosacral facet injections and 15% for cervical-thoracic facet injections (per 100,000 Medicare enrollees). The largest growth occurred from 2000 to 2006 (25% growth per year for lumbosacral and 32% for cervical-thoracic injections per 100,000 Medicare enrollees) and this leveled off from 2007 to 2012 (-3% growth per year for lumbosacral and -2% for cervical-thoracic injections per 100,000 Medicare enrollees). The biggest drop in these procedures was in 2010, when there was a drop of 14

  13. Increased Pelvic Incidence is Associated With a More Coronal Facet Orientation in the Lower Lumbar Spine: A Cadaveric Study of 599 Lumbar Spines.

    Science.gov (United States)

    Weinberg, Douglas S; Xie, Katherine K; Liu, Raymond W; Gebhart, Jeremy J; Gordon, Zachary L

    2016-10-01

    An anatomic study of facet angle orientation and morphology of the lumbar spine was performed. The aim of this study was to determine how age, gender, race, and pelvic incidence (PI) correlate with facet orientation in the lumbar spine. Lumbar facet orientation has important implications in the development of numerous pathologies of the spine, including arthritis, spondylolisthesis, and adult spinal deformity. Preliminary reports have suggested that sagittal balance of the spine may contribute to facet joint orientation. We therefore designed an anatomic study to investigate the relationship between PI and facet orientation, within the context of age, gender, and race. Five hundred ninety-nine cadaveric lumbar spines were obtained from the Hamann-Todd osteological collection. It was determined that facet angle was most reliably assessed by measuring the angle between the superior articular facet and the spinous process. Facet angles were measured bilaterally at each level from T12-L1 through L5-S1 in every specimen. Multivariate regression analysis was used to determine independent predictors of facet angle at each level. Facet angle increased rostrally to caudally, from 22.6 ± 8.3° at T12-L1 to 49.1 ± 12.4° at L5-S1. Cadaver age was an independent predictor of a more sagittal facet angle at lower spinal levels. Caucasian race was an independent predictor of increasing facet angle. Increased PI had no effect on facet angle at T12-L1, L1-L2, L2-L3, or L3-L4, although was a significant predictor of more coronally oriented facet joints at L4-L5 (standardized beta 0.096, P = 0.009) and L5-S1 (standardized beta 0.079, P = 0.032). The results of this study provide important data regarding differences in facet angle that exists between individuals. Moreover, the results of this study suggest that facet joints do possess the ability to remodel over time, perhaps in response to perturbations of sagittal balance, osteophyte formation, or other yet to be

  14. STUDY OF CUSTOMERS’ LOYALTY: DIMENSIONS AND FACETS

    Directory of Open Access Journals (Sweden)

    Claudia BOBÂLCĂ

    2013-06-01

    Full Text Available The purpose of this study is to identify the main aspects investigated in the study of customer loyalty regarding different dimensions and facets of loyalty. Analyzing the academic literature on this subject, we identified two main directions: (a the approachings of loyalty on its dimensions (one, two or four dimensions; (b the approachings of loyalty on its facets (effects. The main facets of loyalty are repatronage intentions, word-of-mouth intentions and buying frequency. Our approach is a theoretical one and we used documentary research. Identifying and analyzing the dimensions and facets of loyalty are important stages for any loyalty program that a company should implement, regardless of its field of activity.

  15. FACET: SLAC___s New User Facility

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, C.I.; Decker, F.-J.; England, R.J.; Erickson, R.A.; Hast, C.; Hogan, M.J.; Li, S.Z.; Litos, M.D.; Nosochkov, Y.; Seeman, J.T.; Sheppard, J.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

    2012-05-16

    FACET (Facility for Advanced Accelerator Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. The first User Run started in spring 2012 with 20 GeV, 3 nC electron beams. The facility is designed to provide short (20 {micro}m) bunches and small (20 {micro}m wide) spot sizes, producing uniquely high power beams. FACET supports studies from many fields but in particular those of Plasma Wakefield Acceleration and Dielectric Wakefield Acceleration. The creation of drive and witness bunches and shaped bunch profiles is possible with 'Notch' Collimation. FACET is also a source of THz radiation for material studies. Positrons will be available at FACET in future user runs. We present the User Facility and the available tools and opportunities for future experiments.

  16. Joint positioning sense, perceived force level and two-point discrimination tests of young and active elderly adults

    OpenAIRE

    Franco,Priscila G.; Santos, Karini B.; André L. F. Rodacki

    2015-01-01

    Background: Changes in the proprioceptive system are associated with aging. Proprioception is important to maintaining and/or recovering balance and to reducing the risk of falls. Objective: To compare the performance of young and active elderly adults in three proprioceptive tests. Method: Twenty-one active elderly participants (66.9±5.5 years) and 21 healthy young participants (24.6±3.9 years) were evaluated in the following tests: perception of position of the ankle and hip joints, perceiv...

  17. FACET: Future ATM Concepts Evaluation Tool

    Science.gov (United States)

    Bilmoria, Karl D.; Banavar, Sridhar; Chatterji, Gano B.; Sheth, Kapil S.; Grabbe, Shon

    2000-01-01

    FACET (Future ATM Concepts Evaluation Tool) is an Air Traffic Management research tool being developed at the NASA Ames Research Center. This paper describes the design, architecture and functionalities of FACET. The purpose of FACET is to provide E simulation environment for exploration, development and evaluation of advanced ATM concepts. Examples of these concepts include new ATM paradigms such as Distributed Air-Ground Traffic Management, airspace redesign and new Decision Support Tools (DSTs) for controllers working within the operational procedures of the existing air traffic control system. FACET is currently capable of modeling system-wide en route airspace operations over the contiguous United States. Airspace models (e.g., Center/sector boundaries, airways, locations of navigation aids and airports) are available from databases. A core capability of FACET is the modeling of aircraft trajectories. Using round-earth kinematic equations, aircraft can be flown along flight plan routes or great circle routes as they climb, cruise and descend according to their individual aircraft-type performance models. Performance parameters (e.g., climb/descent rates and speeds, cruise speeds) are obtained from data table lookups. Heading, airspeed and altitude-rate dynamics are also modeled. Additional functionalities will be added as necessary for specific applications. FACET software is written in Java and C programming languages. It is platform-independent, and can be run on a variety of computers. FACET has been designed with a modular software architecture to enable rapid integration of research prototype implementations of new ATM concepts. There are several advanced ATM concepts that are currently being implemented in FACET airborne separation assurance, dynamic density predictions, airspace redesign (re-sectorization), benefits of a controller DST for direct-routing, and the integration of commercial space transportation system operations into the U.S. National

  18. FACET: Future ATM Concepts Evaluation Tool

    Science.gov (United States)

    Bilmoria, Karl D.; Banavar, Sridhar; Chatterji, Gano B.; Sheth, Kapil S.; Grabbe, Shon

    2000-01-01

    FACET (Future ATM Concepts Evaluation Tool) is an Air Traffic Management research tool being developed at the NASA Ames Research Center. This paper describes the design, architecture and functionalities of FACET. The purpose of FACET is to provide E simulation environment for exploration, development and evaluation of advanced ATM concepts. Examples of these concepts include new ATM paradigms such as Distributed Air-Ground Traffic Management, airspace redesign and new Decision Support Tools (DSTs) for controllers working within the operational procedures of the existing air traffic control system. FACET is currently capable of modeling system-wide en route airspace operations over the contiguous United States. Airspace models (e.g., Center/sector boundaries, airways, locations of navigation aids and airports) are available from databases. A core capability of FACET is the modeling of aircraft trajectories. Using round-earth kinematic equations, aircraft can be flown along flight plan routes or great circle routes as they climb, cruise and descend according to their individual aircraft-type performance models. Performance parameters (e.g., climb/descent rates and speeds, cruise speeds) are obtained from data table lookups. Heading, airspeed and altitude-rate dynamics are also modeled. Additional functionalities will be added as necessary for specific applications. FACET software is written in Java and C programming languages. It is platform-independent, and can be run on a variety of computers. FACET has been designed with a modular software architecture to enable rapid integration of research prototype implementations of new ATM concepts. There are several advanced ATM concepts that are currently being implemented in FACET airborne separation assurance, dynamic density predictions, airspace redesign (re-sectorization), benefits of a controller DST for direct-routing, and the integration of commercial space transportation system operations into the U.S. National

  19. Facets of Emotional Clarity and Suspiciousness

    OpenAIRE

    Boden, Matthew Tyler; Berenbaum, Howard

    2012-01-01

    In a college student sample, we explored the relations between individual differences in facets of emotional clarity and suspiciousness. Previous theory and research has treated emotional clarity as a one-dimensional construct. Boden and Berenbaum (2011) proposed that a second facet of emotional clarity, source awareness (a general understanding of the cause of their emotions), could be distinguished from type awareness (a general understanding of the type of emotions [anger, fear] experience...

  20. Superior facet syndrome. Findings on metrizamide CT myelography

    Energy Technology Data Exchange (ETDEWEB)

    Kubo, Yoshichika; Igarashi, Seishi; Koyama, Tsunemaro

    1985-02-01

    Sciatica caused by root entrapment in the lateral recess was named superior facet syndrome by Epstein in 1972. Few reports on this subject based on large numbers of cases have been documented to date. Of the patients with sciatica, 32 patients were diagnosed to have root entrapment at the lateral recess L5 or/and S1 lumbar spine. Out of 32 patients, 20 patients were operated on and the lateral entrapment was recognized in all of surgical cases. Neuroradiological findings, especially of metrizamide CT (met. CT), were documented in detail. Thirty two patients were classified in three types according to radiological findings. They were congenital or developmental, degenerative, and combined type, respectively. Fourteen cases belonged to the congenital type, 13 to the degenerative and 5 to the combined type. Each group had the mean ages of 23.4, 53.8, and 36.8 years old, respectively. Of 32 cases the entrapment occured in 47 L5 roots and 11 S1 roots. There was no remarkable laterality. In operation the unroofing of the lateral recess were done and the sciatica subsided postoperatively in all of surgical cases. Met. CT revealed extreme medial protrusion of the superior articular joint in 18 of 24 cases(75%) and none filling of the root in the lateral recess in 21 of 24 cases (87.5%). In the degenerative type, met. CT showed some degenerative changes that were hypertrophy or deformity of the articular joints and spur formation of the vertebral body. In contrast to met. CT, metrizamide myelography revealed only slight changes, which were poor filling of the root before it turned out the pedicle of lateral compression of the root. In plain films or lumbar spine articular joints at Lsub(4/5) were formed in coronal plane in 69% of cases of the L5 root entrapment. Met. CT using ReView technique was of great diagnostic value in superior facet syndrome.

  1. The influence of simulated transversus abdominis muscle force on sacroiliac joint flexibility during asymmetric moment application to the pelvis

    NARCIS (Netherlands)

    Gnat, R; Spoor, K; Pool-Goudzwaard, A.L.

    2015-01-01

    AbstractBACKGROUND:The role of so-called local muscle system in motor control of the lower back and pelvis is a subject of ongoing debate. Prevailing beliefs in stabilizing function of this system were recently challenged. This study investigated the impact of in vitro simulated force of transversel

  2. Characterization of the tensile properties of friction stir welded aluminum alloy joints based on axial force, traverse speed, and rotational speed

    Science.gov (United States)

    Panda, Biranchi; Garg, A.; Jian, Zhang; Heidarzadeh, Akbar; Gao, Liang

    2016-09-01

    Friction stir welding (FSW) process has gained attention in recent years because of its advantages over the conventional fusion welding process. These advantages include the absence of heat formation in the affected zone and the absence of large distortion, porosity, oxidation, and cracking. Experimental investigations are necessary to understand the physical behavior that causes the high tensile strength of welded joints of different metals and alloys. Existing literature indicates that tensile properties exhibit strong dependence on the rotational speed, traverse speed, and axial force of the tool that was used. Therefore, this study introduces the experimental procedure for measuring tensile properties, namely, ultimate tensile strength (UTS) and tensile elongation of the welded AA 7020 Al alloy. Experimental findings suggest that a welded part with high UTS can be achieved at a lower heat input compared with the high heat input condition. A numerical approach based on genetic programming is employed to produce the functional relationships between tensile properties and the three inputs (rotational speed, traverse speed, and axial force) of the FSW process. The formulated models were validated based on the experimental data, using the statistical metrics. The effect of the three inputs on the tensile properties was investigated using 2D and 3D analyses. A high UTS was achieved, including a rotational speed of 1050 r/min and traverse speed of 95 mm/min. The results also indicate that 8 kN axial force should be set prior to the FSW process.

  3. 热敏灸配合手法复位治疗胸椎小关节紊乱症随机对照观察%Randomized Controlled Trial of Heat-sensitive Point Moxibustion plus Manipulative Reduction for the Treatment of Thoracic Facet Joint Disorder

    Institute of Scientific and Technical Information of China (English)

    郑锦清; 吴峰; 黄漫为; 郑昌岳; 陈宣煌; 黄志华; 李南华

    2015-01-01

    Objective To investigate the clinical efficacy of heat-sensitive point moxibustion plus manipulative reduction in treating thoracic facet joint disorder. Method A single-blind randomized controlled trial was carried out. Eighty-two patients meeting the criteria were randomly allocated to an observation group of 42 cases and a control group of 40 cases. The observation group received heat-sensitive point moxibustion plus manipulative reduction and the control group, TDP plus manipulative reduction. Both groups were treated five times a week, five times as a course for a total of two courses (including the patients cured after less than two courses). The therapeutic effects were evaluated by using the McGill Pain Questionnaire the as the observation index, comparing pre-/post-treatment Pain Rating Index (PRI) scores, Visual Analogous Scale (VAS) scores and Present Pain Intensity (PPI) scores and referring to the Criteria of the Diagnosis of and the Therapeutic Effect on Syndromes in Traditional Chinese Medicine. Result After treatment, the PRI, VAS and PPI scores decreased significantly in both groups (P<0.01) and were lower in the observation group than in the control group (P<0.01). The cure rate was 57.1% (24/42) in the observation group, which was significantly higher than 27.5% in the control group (11/40,P<0.01). The total efficacy rate was 95.2% (40/42) in the observation group, which was significantly higher than 80.0% in the control group (32/40,P<0.01). Conclusion Heat-sensitive point moxibustion plus manipulative reduction has a very good therapeutic effect on thoracic facet joint disorder. The effect is significantly better than that in the control group.%目的:观察热敏灸配合手法复位治疗胸椎小关节紊乱症的临床疗效,探索一种新的组合疗法。方法采用单盲、随机、对照研究方法,将符合条件的82例患者随机分为两组,观察组42例,给予热敏灸配合手法复位治疗;对照组40例,给予TDP 配

  4. The Air Force Needs to Improve Cost-Effectiveness and Availability of the Joint Surveillance Target Attack Radar System (Redacted)

    Science.gov (United States)

    2016-11-01

    Introduction Objective We determined whether the Air Force made cost-effective purchases on the performance-based logistics ( PBL ) contract to support...logistics ( PBL ) contract to support JSTARS. Specifically, the JSTARS contracting officer did not establish adequate oversight procedures to validate the...must develop and implement PBL strategies that improve total system availability while minimizing cost and the size of spare parts inventory

  5. A complexity science-based framework for global joint operations analysis to support force projection: LDRD Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). System Sustainment & Readiness Technologies Dept.

    2015-01-01

    The military is undergoing a significant transformation as it modernizes for the information age and adapts to address an emerging asymmetric threat beyond traditional cold war era adversaries. Techniques such as traditional large-scale, joint services war gaming analysis are no longer adequate to support program evaluation activities and mission planning analysis at the enterprise level because the operating environment is evolving too quickly. New analytical capabilities are necessary to address modernization of the Department of Defense (DoD) enterprise. This presents significant opportunity to Sandia in supporting the nation at this transformational enterprise scale. Although Sandia has significant experience with engineering system of systems (SoS) and Complex Adaptive System of Systems (CASoS), significant fundamental research is required to develop modeling, simulation and analysis capabilities at the enterprise scale. This report documents an enterprise modeling framework which will enable senior level decision makers to better understand their enterprise and required future investments.

  6. On the role of the patella, ACL and joint contact forces in the extension of the knee.

    Directory of Open Access Journals (Sweden)

    Daniel J Cleather

    Full Text Available Traditional descriptions of the knee suggest that the function of the patella is to facilitate knee extension by increasing the moment arm of the quadriceps muscles. Through modelling and evidence from the literature it is shown in this paper that the presence of the patella makes the ability of the quadriceps to rotate the thigh greater than their ability to rotate the tibia. Furthermore, this difference increases as the knee is flexed, thus demonstrating a pattern that is consistent with many human movements. This paper also shows that the anterior cruciate ligament plays a previously unheralded role in extending the shank and that translation at the tibiofemoral and patellofemoral joints is important in improving the capacity for thigh rotation when the knee is flexed. This study provides new insights as to how the structure of the knee is adapted to its purpose and illustrates how the functional anatomy of the knee contributes to its extension function.

  7. On the Role of the Patella, ACL and Joint Contact Forces in the Extension of the Knee

    Science.gov (United States)

    Cleather, Daniel J.; Southgate, Dominic F. L.; Bull, Anthony M. J.

    2014-01-01

    Traditional descriptions of the knee suggest that the function of the patella is to facilitate knee extension by increasing the moment arm of the quadriceps muscles. Through modelling and evidence from the literature it is shown in this paper that the presence of the patella makes the ability of the quadriceps to rotate the thigh greater than their ability to rotate the tibia. Furthermore, this difference increases as the knee is flexed, thus demonstrating a pattern that is consistent with many human movements. This paper also shows that the anterior cruciate ligament plays a previously unheralded role in extending the shank and that translation at the tibiofemoral and patellofemoral joints is important in improving the capacity for thigh rotation when the knee is flexed. This study provides new insights as to how the structure of the knee is adapted to its purpose and illustrates how the functional anatomy of the knee contributes to its extension function. PMID:25536067

  8. A Complexity Science-Based Framework for Global Joint Operations Analysis to Support Force Projection: LDRD Final Report.

    Energy Technology Data Exchange (ETDEWEB)

    Lawton, Craig R.

    2015-01-01

    The military is undergoing a significant transformation as it modernizes for the information age and adapts to address an emerging asymmetric threat beyond traditional cold war era adversaries. Techniques such as traditional large-scale, joint services war gaming analysis are no longer adequate to support program evaluation activities and mission planning analysis at the enterprise level because the operating environment is evolving too quickly. New analytical capabilities are necessary to address modernization of the Department of Defense (DoD) enterprise. This presents significant opportunity to Sandia in supporting the nation at this transformational enterprise scale. Although Sandia has significant experience with engineering system of systems (SoS) and Complex Adaptive System of Systems (CASoS), significant fundamental research is required to develop modeling, simulation and analysis capabilities at the enterprise scale. This report documents an enterprise modeling framework which will enable senior level decision makers to better understand their enterprise and required future investments.

  9. Neuro-based Thumb-tip Force and Joint Angle Modelling for Development of Prosthetic Thumb Control

    Directory of Open Access Journals (Sweden)

    Nor Anija Jalaludin

    2013-10-01

    Full Text Available Human fingers have a specific role that contributes to different hand functions. Among these fingers, the thumb plays the most special function as an anchor to many hand activities. As a result, the loss of the thumb due to traumatic accidents can be catastrophic as proper hand function will be severely limited. In order to solve this problem, a prosthetic thumb is developed to be worn in complementing the function of the rest of the fingers. The movement of the prosthetic device can be naturally controlled by using electromyogram (EMG signals. In this work, the EMG signals from the human muscles were measured in different thumb configurations and thumb-tip forces in flexion movement. The muscles involved are the Adductor Pollicis (AP, Flexor Pollicis Brevis (FPB, Abductor Pollicis Brevis (APB and First Dorsal Interosseous (FDI. The classification of the EMG signals based on different force and thumb configurations is performed using an Artificial Neural Network (ANN. From a series of experiments, the results show that the neural network efficiently classified the signals and a unique set of EMG signals was generated for each thumb movement and force. Therefore, EMG signals were used to control the prosthetic movement with aid from the developed neural network.

  10. Impact of the Weld Geometry on the Stress Intensity Factor of the Welded T-Joint Exposed to the Tensile Force and the Bending Moment

    Directory of Open Access Journals (Sweden)

    Djoković Jelena M.

    2015-12-01

    Full Text Available In this paper it is analyzed the welded T-joint exposed to the axial tensile force and the bending moment, for determining the impact of the weld geometry on the fracture mechanics parameters. The stress intensity factor was calculated analytically, based on the concept of the linear elastic fracture mechanics (LEFM, by application of the Mathematica® programming routine. The presence of the weld was taken into account through the corresponding correction factors. The results show that increase of the size of the triangular welds leads to decrease of the stress intensity factor, while the SIF increases with increase of the welds’ width. The ratio of the two welded plates’ thicknesses shows that plate thicknesses do not exhibit significant influence on the stress intensity factor behavior.

  11. Average and equilibrium structures of methyl flouride studied by electron diffraction. A joint analysis with rotational constants and cubic force constants

    Science.gov (United States)

    Egawa, Toru; Yamamoto, Satoshi; Nakata, Munetaka; Kuchitsu, Kozo

    1987-02-01

    Electron diffraction intensity of methyl fluoride was measured and analyzed jointly with the rotational constants, Ao and Bo, of the normal species. The following structure was derived: rg(CF) = 1.391(1) Å, rg(CH) = 1.108(1) Å and β z(FCH) = 108.7(2)°, where the numbers in parentheses represent estimated limits of error. The effective anharmonic constants were derived using the rotational constants and the l-type doubling constants; the cubic force constants calculated by Kondo using a 6-311G** (MP2) basis set were also incorporated in the analysis. The following equilibrium structure was derived from the rz structure and the effective anharmonic constants: re(CF) = 1.383(1) Å, re(CH) = 1.086(2) Å and β e(FCH) = 108.8(3)°.

  12. Impact of the Weld Geometry on the Stress Intensity Factor of the Welded T-Joint Exposed to the Tensile Force and the Bending Moment

    Science.gov (United States)

    Djoković, Jelena M.; Nikolić, Ružica R.; Bujňák, Ján

    2015-12-01

    In this paper it is analyzed the welded T-joint exposed to the axial tensile force and the bending moment, for determining the impact of the weld geometry on the fracture mechanics parameters. The stress intensity factor was calculated analytically, based on the concept of the linear elastic fracture mechanics (LEFM), by application of the Mathematica® programming routine. The presence of the weld was taken into account through the corresponding correction factors. The results show that increase of the size of the triangular welds leads to decrease of the stress intensity factor, while the SIF increases with increase of the welds' width. The ratio of the two welded plates' thicknesses shows that plate thicknesses do not exhibit significant influence on the stress intensity factor behavior.

  13. Current guidelines for the evaluation and management of atopic dermatitis: A comparison of the Joint Task Force Practice Parameter and American Academy of Dermatology guidelines.

    Science.gov (United States)

    Eichenfield, Lawrence F; Ahluwalia, Jusleen; Waldman, Andrea; Borok, Jenna; Udkoff, Jeremy; Boguniewicz, Mark

    2017-04-01

    Atopic dermatitis (AD) is a chronic pruritic inflammatory disease that commonly presents in the pediatric population. Although definitions and diagnosis of AD have largely been agreed upon, allergists and dermatologists have similar and divergent approaches to the management of AD. This review facilitated integration of the American Academy of Allergy, Asthma & Immunology/American College of Allergy, Asthma & Immunology Joint Task Force 2012 AD Practice Parameter and the 2014 American Academy of Dermatology guidelines to highlight the basic principles of AD management and discuss therapies and management of AD from the distinct perspectives of the allergist and dermatologist. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  14. Diagnosis and management of rhinitis: complete guidelines of the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology. American Academy of Allergy, Asthma, and Immunology.

    Science.gov (United States)

    Dykewicz, M S; Fineman, S; Skoner, D P; Nicklas, R; Lee, R; Blessing-Moore, J; Li, J T; Bernstein, I L; Berger, W; Spector, S; Schuller, D

    1998-11-01

    This document contains complete guidelines for diagnosis and management of rhinitis developed by the Joint Task Force on Practice Parameters in Allergy, Asthma and Immunology, representing the American Academy of Allergy, Asthma and Immunology, the American College of Allergy, Asthma and Immunology and the Joint Council on Allergy, Asthma and Immunology. The guidelines are comprehensive and begin with statements on clinical characteristics and diagnosis of different forms of rhinitis (allergic, non-allergic, occupational rhinitis, hormonal rhinitis [pregnancy and hypothyroidism], drug-induced rhinitis, rhinitis from food ingestion), and other conditions that may be confused with rhinitis. Recommendations on patient evaluation discuss appropriate use of history, physical examination, and diagnostic testing, as well as unproven or inappropriate techniques that should not be used. Parameters on management include use of environmental control measures, pharmacologic therapy including recently introduced therapies and allergen immunotherapy. Because of the risks to patients and society from sedation and performance impairment caused by first generation antihistamines, second generation antihistamines that reduce or eliminate these side effects should usually be considered before first generation antihistamines for the treatment of allergic rhinitis. The document emphasizes the importance of rhinitis management for comorbid conditions (asthma, sinusitis, otitis media). Guidelines are also presented on special considerations in patients subsets (children, the elderly, pregnancy, athletes and patients with rhinitis medicamentosa); and when consultation with an allergist-immunologist should be considered.

  15. Joint Inflammation and Early Degeneration Induced by High-Force Reaching Are Attenuated by Ibuprofen in an Animal Model of Work-Related Musculoskeletal Disorder

    Directory of Open Access Journals (Sweden)

    Jeffrey B. Driban

    2011-01-01

    Full Text Available We used our voluntary rat model of reaching and grasping to study the effect of performing a high-repetition and high-force (HRHF task for 12 weeks on wrist joints. We also studied the effectiveness of ibuprofen, administered in the last 8 weeks, in attenuating HRHF-induced changes in these joints. With HRHF task performance, ED1+ and COX2+ cells were present in subchondral radius, carpal bones and synovium; IL-1alpha and TNF-alpha increased in distal radius/ulna/carpal bones; chondrocytes stained with Terminal deoxynucleotidyl Transferase- (TDT- mediated dUTP-biotin nick end-labeling (TUNEL increased in wrist articular cartilages; superficial structural changes (e.g., pannus and reduced proteoglycan staining were observed in wrist articular cartilages. These changes were not present in normal controls or ibuprofen treated rats, although IL-1alpha was increased in reach limbs of trained controls. HRHF-induced increases in serum C1,2C (a biomarker of collagen I and II degradation, and the ratio of collagen degradation to synthesis (C1,2C/CPII; the latter a biomarker of collage type II synthesis were also attenuated by ibuprofen. Thus, ibuprofen treatment was effective in attenuating HRHF-induced inflammation and early articular cartilage degeneration.

  16. Individual-specific muscle maximum force estimation using ultrasound for ankle joint torque prediction using an EMG-driven Hill-type model.

    Science.gov (United States)

    de Oliveira, Liliam Fernandes; Menegaldo, Luciano Luporini

    2010-10-19

    EMG-driven models can be used to estimate muscle force in biomechanical systems. Collected and processed EMG readings are used as the input of a dynamic system, which is integrated numerically. This approach requires the definition of a reasonably large set of parameters. Some of these vary widely among subjects, and slight inaccuracies in such parameters can lead to large model output errors. One of these parameters is the maximum voluntary contraction force (F(om)). This paper proposes an approach to find F(om) by estimating muscle physiological cross-sectional area (PCSA) using ultrasound (US), which is multiplied by a realistic value of maximum muscle specific tension. Ultrasound is used to measure muscle thickness, which allows for the determination of muscle volume through regression equations. Soleus, gastrocnemius medialis and gastrocnemius lateralis PCSAs are estimated using published volume proportions among leg muscles, which also requires measurements of muscle fiber length and pennation angle by US. F(om) obtained by this approach and from data widely cited in the literature was used to comparatively test a Hill-type EMG-driven model of the ankle joint. The model uses 3 EMGs (Soleus, gastrocnemius medialis and gastrocnemius lateralis) as inputs with joint torque as the output. The EMG signals were obtained in a series of experiments carried out with 8 adult male subjects, who performed an isometric contraction protocol consisting of 10s step contractions at 20% and 60% of the maximum voluntary contraction level. Isometric torque was simultaneously collected using a dynamometer. A statistically significant reduction in the root mean square error was observed when US-obtained F(om) was used, as compared to F(om) from the literature.

  17. Effect of diode-laser parameters on shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder on Au/Ni/Cu pad

    Institute of Scientific and Technical Information of China (English)

    WANG Jian-xin; XUE Song-bai; FANG Dian-song; JU Jin-long; HAN Zong-jie; YAO Li-hua

    2006-01-01

    Soldering experiments with Sn-3.5Ag-0.5Cu lead-free solder on Au/Ni/Cu pad were carried out by means of diode-laser and IR reflow soldering methods respectively. The influence of different heating methods as well as output power of diode-laser on shear force of micro-joints was studied and the relationship between the shear force and microstructures of micro-joints was analyzed.The results indicate that the formation of intermetallic compound Ag3Sn is the key factor to affect the shear force and the fine eutectic network structures of micro-joints as well as the dispersion morphology of fine compound Ag3Sn, in which eutectic network band is responsible for the improvement of the shear force of micro-joints soldered with Sn-Ag-Cu lead-free solder. With the increases of output power of diode-laser, the shear force and the microstructures change obviously. The eutectic network structures of micro-joints soldered with diode-laser soldering method are more homogeneous and the grains of Ag3Sn compounds are finer in the range of near optimal output power than those soldered with IR reflow soldering method, so the shear force is also higher than that using IR reflow soldering method. When the output power value of diode-laser is about 41.0 W, the shear force exhibits the highest value that is 70% higher than that using IR reflow soldering method.

  18. Reconstructions and faceting of H-covered Al(111)

    CERN Document Server

    Stumpf, R

    1996-01-01

    First principles calculations show that H overlayers induce a honeycomb vacancy reconstruction on Al(111). Above one ML H coverage, Al(111) facets into surfaces vicinal to (111), with {100} faceted single and double steps and vacancies on the {111} terraces. These H induced reconstructions are stable because H binds more strongly to {100} than to {111} facets. Faceting of Al(111) explains step bunching in H-mediated epitaxy of Al(111). H-covered Al(100) is stable against faceting.

  19. The peroneocuboid joint: morphogenesis and anatomical study.

    Science.gov (United States)

    Guimerá, V; Lafuente, A; Zambrana, L; Rodriguez-Niedenführ, M; Sañudo, J R; Vazquez, T

    2015-01-01

    The peroneocuboid joint, between the peroneus longus tendon and the cuboid bone, has not been anatomically well-defined and no embryological study has been published. Furthermore, the ossification of the os peroneum (a sesamoid inside the peroneus longus tendon) and its associated pathology has been considered to be generated by orthostatic and/or mechanical loads. A light microscopy analysis of serially sectioned human embryonic and fetal feet, the analysis of human adult feet by means of standard macroscopic dissection, X-ray and histological techniques have been carried out. The peroneus longus tendon was fully visible until its insertion in the 1st metatarsal bone already at embryonic stage 23 (56-57 days). The peroneocuboid joint cavity appeared at the transition of the embryonic to the fetal period (8-9th week of gestation) and was independent of the proximal synovial sheath. The joint cavity extended from the level of the calcaneocuboid joint all the way to the insertion of the peroneus longus tendon in the 1st metatarsal bone. The frenular ligaments, fixing the peroneus longus tendon to the 5th metatarsal bone or the long calcaneocuboid ligament, developed in the embryonic period. The peroneus longus tendon presented a thickening in the area surrounding the cuboid bone as early as the fetal period. This thickening may be considered the precursor of the os peroneum and was similar in shape and in size relation to the tendon, to the os peroneum observed in adults. To the best of our knowledge, this is the first study to show that the os peroneum, articular facets of the peroneus longus tendon and cuboid bone, the peroneocuboid joint and the frenular ligaments appear during the embryonic/fetal development period and therefore they can not be generated exclusively by orthostatic and mechanical forces or pathological processes.

  20. Regression relationships of landing height with ground reaction forces, knee flexion angles, angular velocities and joint powers during double-leg landing.

    Science.gov (United States)

    Yeow, C H; Lee, Peter V S; Goh, James C H

    2009-10-01

    Ground reaction forces (GRF), knee flexion angles, angular velocities and joint powers are unknown at large landing heights, which are infeasible for laboratory testing. However, this information is important for understanding lower extremity injury mechanisms. We sought to determine regression relationships of landing height with these parameters during landing so as to facilitate estimation of these parameters at large landing heights. Five healthy male subjects performed landing tasks from heights of 0.15-1.05 m onto a force-plate. Motion capture system was used to obtain knee flexion angles during landing via passive markers placed on the lower body. An iterative regression model, involving simple linear/exponential/natural logarithmic functions, was used to fit regression equations to experimental data. Peak GRF followed an exponential regression relationship (R(2)=0.90-0.99, p<0.001; power=0.987-0.998). Peak GRF slope and impulse also had an exponential relationship (R(2)=0.90-0.96, p<0.001; power=0.980-0.997 and R(2)=0.90-0.99, p<0.001; power=0.990-1.000 respectively) with landing height. Knee flexion angle at initial contact and at peak GRF had an inverse-exponential regression relationship (R(2)=0.81-0.99, p<0.001-p=0.006; power=0.834-0.978 and R(2)=0.84-0.97, p<0.001-p=0.004; power=0.873-0.999 respectively). There was also an inverse-exponential relationship between peak knee flexion angular velocity and landing height (R(2)=0.86-0.96, p<0.001; power=0.935-0.994). Peak knee joint power demonstrated a substantial linear relationship (R(2)=0.98-1.00, p<0.001; power=0.990-1.000). The parameters analyzed in this study are highly dependent on landing height. The exponential increase in peak GRF parameters and the relatively slower increase in knee flexion angles, angular velocities and joint power may synergistically lead to an exacerbated lower extremity injury risk at large landing heights.

  1. Dynesys dynamic stabilization-related facet arthrodesis.

    Science.gov (United States)

    Fay, Li-Yu; Chang, Peng-Yuan; Wu, Jau-Ching; Huang, Wen-Cheng; Wang, Chun-Hao; Tsai, Tzu-Yun; Tu, Tsung-Hsi; Chang, Hsuan-Kan; Wu, Ching-Lan; Cheng, Henrich

    2016-01-01

    OBJECTIVE Dynamic stabilization devices are designed to stabilize the spine while preserving some motion. However, there have been reports demonstrating limited motion at the instrumented level of the lumbar spine after Dynesys dynamic stabilization (DDS). The causes of this limited motion and its actual effects on outcomes after DDS remain elusive. In this study, the authors investigate the incidence of unintended facet arthrodesis after DDS and clinical outcomes. METHODS This retrospective study included 80 consecutive patients with 1- or 2-level lumbar spinal stenosis who underwent laminectomy and DDS. All medical records, radiological data, and clinical evaluations were analyzed. Imaging studies included pre- and postoperative radiographs, MR images, and CT scans. Clinical outcomes were measured by a visual analog scale (VAS) for back and leg pain, the Oswestry Disability Index (ODI), and Japanese Orthopaedic Association (JOA) scores. Furthermore, all patients had undergone postoperative CT for the detection of unintended arthrodesis of the facets at the indexed level, and range of motion was measured on standing dynamic radiographs. RESULTS A total of 70 patients (87.5%) with a mean age of 64.0 years completed the minimum 24-month postoperative follow-up (mean duration 29.9 months). Unintended facet arthrodesis at the DDS instrumented level was demonstrated by CT in 38 (54.3%) of the 70 patients. The mean age of patients who had facet arthrodesis was 9.8 years greater than that of the patients who did not (68.3 vs 58.5 years, p = 0.009). There were no significant differences in clinical outcomes, including VAS back and leg pain, ODI, and JOA scores between patients with and without the unintended facet arthrodesis. Furthermore, those patients older than 60 years were more likely to have unintended facet arthrodesis (OR 12.42) and immobile spinal segments (OR 2.96) after DDS. Regardless of whether unintended facet arthrodesis was present or not, clinical

  2. Lumbo-pelvic joint protection against antigravity forces: motor control and segmental stiffness assessed with magnetic resonance imaging.

    Science.gov (United States)

    Richardson, C A; Hides, J A; Wilson, S; Stanton, W; Snijders, C J

    2004-07-01

    The antigravity muscles of the lumbo-pelvic region, especially transversus abdominis (TrA), are important for the protection and support of the weightbearing joints. Measures of TrA function (the response to the postural cue of drawing in the abdominal wall) have been developed and quantified using magnetic resonance imaging (MRI). Cross-sections through the trunk allowed muscle contraction as well as the large fascial attachments of the TrA to be visualized. The cross sectional area (CSA) of the deep musculo-fascial system was measured at rest and in the contracted state, using static images as well as a cine sequence. In this developmental study, MRI measures were undertaken on a small sample of low back pain (LBP) and non LBP subjects. Results demonstrated that, in non LBP subjects, the draw in action produced a symmetrical deep musculo-fascial "corset" which encircles the abdomen. This study demonstrated a difference in this "corset" measure between subjects with and without LBP. These measures may also prove useful to quantify the effect of unloading in bedrest and microgravity exposure.

  3. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc

    Energy Technology Data Exchange (ETDEWEB)

    Schertz, P.T.; Brown, D.C.; Konnerth, A. III (Solar Kinetics, Inc., Dallas, TX (United States))

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/m{sup 2} (2.4lbs/ft{sup 2}). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the from membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/m{sup 2} at a production rate of 10,000 facets per year and $115, 000/m{sup 2}-at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatablility and facet performance in typical operating conditions. 18 refs., 36 figs., 11 tabs.

  4. Facet development for a faceted stretched-membrane dish by Solar Kinetics, Inc.

    Science.gov (United States)

    Schertz, P. T.; Brown, D. C.; Konnerth, A., III

    1991-07-01

    A 3.6-meter diameter stretched-membrane optical facet for a parabolic dish has been successfully designed and demonstrated under contract with Sandia National Laboratories. Twelve facets identical to them will be used to make the lightweight reflector of the dish. The project goal of 2.5-mrad surface accuracy was met with each of the two full-sized prototypes, and accuracies of as low as 1.1 mrad were achieved. The facet weight is 11.7 kg/sq m (2.4 lbs/sq ft). The facet is similar in construction to the successful stretched-membrane heliostat; it has two thin metal membranes attached to a ring. However, the front membrane for this facet is plastically formed at the factor in order to achieve a shorter facet f/D (approximately 3.0). A passive tether restrains the front membrane when not in operation, that is, when the stabilizing vacuum is off. The optical surface is achieved with a silvered-acrylic film laminated to the metal membrane. The facet is expected to cost $55.40/sq m at a production rate of 10,000 facets per year and $115,000/sq m at a production rate of 500 facets a year. Several key issues have been resolved. Stress concentrations due to seams in the reflective laminate did not cause membrane rupture during forming as they have for dishes with lower focal length-to-diameter ratios. The laminate survived the forming process and simulated operation without deterioration. The optical effect of the tether on the membrane was tested and found to be very small. Most important, highly accurate shapes were obtained using a simple forming procedure. Additional tests are needed to demonstrate process repeatability and facet performance in typical operating conditions.

  5. 受腐蚀的铰缝结构的受力性能分析%Force capability analysis of hinge joint structure suffering corrosion

    Institute of Scientific and Technical Information of China (English)

    彭利英; 卫军; 余崇

    2012-01-01

    对受腐蚀的铰缝结构的受力性能进行试验研究和有限元分析.通过考虑材料弹塑性、非线性以及界面接触等的影响,揭示后浇铰缝与预制板之间纵向抗剪黏结力对结构整体性的影响规律.研究结果表明:腐蚀作用造成的后浇铰缝与预制板之间黏结力下降,由此导致铰缝传递水平剪力的能力大大降低,预制板结构体系的受力形式有可能由整体受力向水平面内组合板受力形式转变.%The effect of corrosion environment on mid-hinge joint was studied through experiment and finite element analysis. The plasticity, nonlinear, accurate concrete constitutive model and complex interaction of the new and old concrete were studied to reveal the effect law of horizontal cohesive force on the structure integrity. The results show that recession of the adherent force between old and new concrete has deep influence on the structure integrity deeply- This influence converts the integrated structure to a composite one and results in the capacity recession of transferring horizontal shear.

  6. Efficacy of a trunk orthosis with joints providing resistive force on low-back load in elderly persons during static standing

    Directory of Open Access Journals (Sweden)

    Katsuhira J

    2015-09-01

    Full Text Available Junji Katsuhira,1 Ko Matsudaira,2 Tadashi Yasui,3 Shinno Iijima,4 Akihiro Ito4 1Department of Nursing and Rehabilitation Science at Odawara, International University of Health and Welfare, Odawara, Kanagawa, 2Department of Medical Research and Management for Musculoskeletal Pain, 22nd Century Medical and Research Center, The University of Tokyo, Tokyo, 3Kawamura-Gishi Company, Ltd., Daito-shi, Osaka, 4Graduate School of International University of Health and Welfare, Otawara, Tochigi, Japan Purpose: Postural alignment of elderly people becomes poor due to aging, possibly leading to low-back pain and spinal deformity. Although there are several interventions for treating these conditions, no previous study has reported the effectiveness of a spinal orthosis or lumbosacral orthosis (LSO in healthy elderly people without specific spinal deformity. We therefore developed a trunk orthosis to decrease low-back muscle activity while training good postural alignment through resistive force provided by joints with springs (here, called the ORF, which stands for orthosis with joints providing resistive force as a preventive method against abnormal posture and low-back pain in healthy elderly persons. Patients and methods: Fifteen community-dwelling elderly men participated in this study. Participants stood freely for 10 seconds in a laboratory setting under three conditions: without an orthosis, with the ORF, and with an LSO. The Damen corset LSO was selected as it is frequently prescribed for patients with low-back pain. Postural alignment during static standing was recorded using a three-dimensional motion capture system employing infrared cameras. Two force plates were used to record center of pressure. Electromyograms were obtained for bilateral erector spinae (ES, left internal abdominal oblique, and right gluteus medius muscles. Results: Pelvis forward tilt angle tended to increase while wearing the ORF and decrease while wearing the LSO, but these

  7. Clinical Observation of Glucosamine Hydrochloride Combined with Chondroitin Sulfate in the Treatment of Lumbar Facet Joint Osteoarthritis%盐酸氨基葡萄糖联合硫酸软骨素治疗腰椎小关节骨关节炎的临床观察

    Institute of Scientific and Technical Information of China (English)

    杨勇; 陈旭; 昝中学; 苟金平; 吴万军; 古其军

    2012-01-01

    目的 观察比较盐酸氨基葡萄糖单独使用及与硫酸软骨素联合使用治疗腰椎小关节骨关节炎(LFOA)的临床疗效.方法 2009年1月-2011年1月,将80例LFOA患者随机分成两组,A组口服盐酸氨基葡萄糖,B组口服盐酸氨基葡萄糖和硫酸软骨素两种药物,6周为1个疗程,间断治疗4个疗程.分别比较用药前与用药后3、6周及5、8、11个月时的日本骨科协会(JOA)评分、晨僵和压痛程度变化.结果 治疗后,两组的JOA评分在各观察时点均增加,与治疗前比较差异有统计学意义(P<0.05).组间行JOA评分治疗改善率的比较,在各观察时点差异均有统计学意义(P<0.05),B组JOA评分改善率优于A组.治疗3周后,两组晨僵和压痛评分均降低,与本组治疗前比较差异有统计学意义(P<0.05);组间比较,差异亦有统计学意义(P<0.05),B组晨僵和压痛程度均低于A组.第6周,第5、8、11个月,两组组间比较晨僵和压痛程度差异均无统计学意义(P>0.05),但各疗程结束后两组晨僵和压痛程度均呈持续降低趋势.结论 单独应用盐酸氨基葡萄糖及盐酸氨基葡萄糖与硫酸软骨素的联合应用治疗LFOA疗效确切,联合用药优于单独应用盐酸氨基葡萄糖.%Objective To observe the clinical effect of glucosamine hydrochloride or glucosamine hydrochloride and chondroitin sulfate in combination on the treatment of lumbar facet joint osteoarthritis (LFOA). Methods From January 2009 to January 2011, 80 patients with LFOA were randomly divided into 2 groups: group A with medication of glucosamine hydrochloride and group B with medication of glucosamine hydrochloride and chondroitin sulfate in combination. Each group was treated for 4 courses and 6 weeks for every course. The clinical effect from the change of score of the items observed at each point of each group was compared with its' pretreatment, and the clinical effect was compared in the two groups at the same point

  8. [Analysis and discussion on the facet of the spinal column, spiral CT lock multiplanar reconstruction and 
3D reconstruction].

    Science.gov (United States)

    Zheng, Zhifeng; Wang, Shuhang; Si, Donglei

    2015-10-01

    To investigate the imaging appearances and diagnostic value of axial CT scanning, spiral CT multiplanar reconstruction (MPR) and three-dimensional (3D) reconstruction in vertebral facet joints locking.
 A total of 31 cases of vertebral facet joints locking, with injuries in different parts, were recruited to explore their CT features, and to evaluate their advantages in diagnosis against each other.
 Among the CT images of 31 cases with "Hamburger" sign in axial view, there were 21 cases of cervical spine and 10 cases of thoracolumbar segment; in vertical plane of MPR, "top to top" form was formed below the inferior and the superior articular process, accompanied by I° spondylolisthesis and inferior articular process tip fracture; 5 cases were unilateral locked cervical spine; none case for thoracolumbar segment. The inferior articular process was crossed with the superior articular process below and moved forward, formed "back to back" form, accompanied by II°-III° spondylolisthesis. 9 or 6 cases were bilateral or unilateral locking cervical spine, 10 cases were thoracolumbar segment, accompanied by teardrop fracture in the vertebral body below cervical spine. In coronal plane of MPR, inferior articular process showed ingression in different extent, and relied on the superior articular process below or locked in the articular fossa (21 cases for cervical spine); inferior articular process displayed upward displacement or appeared with the superior articular process at the same time, which meant joint structure disappearing thoracolumbar segment (10 cases). In 3D reconstruction, 31 cases displayed clearly in the spatial form of vertebral facet joints locking and the degree of spondylolisthesis of vertebral body.
 MPR and 3D image were more clear and intuitive in vertebral facet joints locking comparing to axial CT scan image. Spiral CT MPR and 3D reconstruction contributed to the diagnosis of vertebral facet joints locking and the reduction of misdiagnoses

  9. Faceting oscillations in nano-ferroelectrics

    Energy Technology Data Exchange (ETDEWEB)

    Scott, J. F., E-mail: jfs32@cam.ac.uk, E-mail: ashok553@nplindia.org [Cavendish Laboratory, Cambridge University, Cambridge (United Kingdom); Kumar, Ashok, E-mail: jfs32@cam.ac.uk, E-mail: ashok553@nplindia.org [CSIR-National Physical Laboratory, Delhi (India)

    2014-08-04

    We observe periodic faceting of 8-nm diameter ferroelectric disks on a 10 s time-scale when thin Pb(Zr{sub 0.52}Ti{sub 0.48})O{sub 3} film is exposed to constant high-resolution transmission electron microscopy beams. The oscillation is between circular disk geometry and sharply faceted hexagons. The behavior is analogous to that of spin structure and magnetic domain wall velocity oscillations in permalloy [Bisig et al., Nat. Commun. 4, 2328 (2013)], involving overshoot and de-pinning from defects [Amann et al., J. Rheol. 57, 149–175 (2013)].

  10. Alignment and focus of mirrored facets of a heliosat

    Energy Technology Data Exchange (ETDEWEB)

    Yellowhair, Julius E; Ho, Clifford Kuofei; Diver, Richard B; Moss, Timothy A

    2013-11-12

    Various technologies pertaining to aligning and focusing mirrored facets of a heliostat are described herein. Updating alignment and/or focus of mirrored facets is undertaken through generation of a theoretical image, wherein the theoretical image is indicative of a reflection of the target via the mirrored facets when the mirrored facets are properly aligned. This theoretical image includes reference points that are overlaid on an image of the target as reflected by the mirrored facets of the heliostat. A technician adjusts alignment/focus of a mirrored facet by causing reflected reference markings to become aligned with the reference points in the theoretical image.

  11. Percutaneous fusion of lumbar facet with bone allograft

    Directory of Open Access Journals (Sweden)

    Félix Dolorit Verdecia

    2015-03-01

    Full Text Available OBJECTIVE: To assess the evolution of the cases treated with percutaneous facet fusion with bone allograft in lumbar facet disease. METHOD: Between 2010 and 2014, 100 patients (59 women and 41 men diagnosed with lumbar facet disease underwent surgery. RESULTS: The lumbar facet fusion with bone allograft shows good clinical results, is performed on an outpatient basis, and presents minimal complications and rapid incorporation of the patient to the activities of daily living. CONCLUSIONS: The lumbar facet fusion with bone allograft appears to be an effective treatment for lumbar facet disease.

  12. Is facet analysis based on rationalism?

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2014-01-01

    , rationalism, historicism/hermeneutics, or pragmatism/critical theory (of which only the last position fully acknowledges the non-neutrality of knowledge organisation). Ranganathan – and the whole facet-analytic school – has formerly been exemplified as a rather clear example of rationalism. Some have objected...

  13. Problem of time: facets and Machian strategy.

    Science.gov (United States)

    Anderson, Edward

    2014-10-01

    The problem of time is that "time" in each of ordinary quantum theory and general relativity are mutually incompatible notions. This causes difficulties in trying to put these two theories together to form a theory of quantum gravity. The problem of time has eight facets in canonical approaches. I clarify that all but one of these facets already occur at the classical level, and reconceptualize and re-name some of these facets as follows. The frozen formalism problem becomes temporal relationalism, the thin sandwich problem becomes configurational relationalism, via the notion of best matching. The problem of observables becomes the problem of beables, and the functional evolution problem becomes the constraint closure problem. I also outline how each of the global and multiple-choice problems of time have their own plurality of facets. This article additionally contains a local resolution to the problem of time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical, and a combined semiclassical-histories-timeless records scheme. I end by delineating the current frontiers of this program toward resolution of the problem of time in the cases of full general relativity and of slightly inhomogeneous cosmology.

  14. Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy

    Directory of Open Access Journals (Sweden)

    Loh JT

    2015-10-01

    Full Text Available Jeffrey T Loh,1 Andrea L Nicol,1 David Elashoff,2 F Michael Ferrante,1 1Department of Anesthesiology, David Geffen School of Medicine, 2Department of Biomathematics, University of California Los Angeles, Los Angeles, CA, USA Background: Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. Materials and methods: A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient's chart was analyzed for treatment technique (early versus advanced Australian, preprocedural visual numeric scale (VNS score, postprocedural VNS score, duration of pain relief, and complications. Results: Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively. The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022. Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. Conclusion: The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in

  15. Differential stress induced by thiol adsorption on facetted nanocrystals.

    Science.gov (United States)

    Watari, Moyu; McKendry, Rachel A; Vögtli, Manuel; Aeppli, Gabriel; Soh, Yeong-Ah; Shi, Xiaowen; Xiong, Gang; Huang, Xiaojing; Harder, Ross; Robinson, Ian K

    2011-09-25

    Polycrystalline gold films coated with thiol-based self-assembled monolayers (SAM) form the basis of a wide range of nanomechanical sensor platforms. The detection of adsorbates with such devices relies on the transmission of mechanical forces, which is mediated by chemically derived stress at the organic-inorganic interface. Here, we show that the structure of a single 300-nm-diameter facetted gold nanocrystal, measured with coherent X-ray diffraction, changes profoundly after the adsorption of one of the simplest SAM-forming organic molecules. On self-assembly of propane thiol, the crystal's flat facets contract radially inwards relative to its spherical regions. Finite-element modelling indicates that this geometry change requires large stresses that are comparable to those observed in cantilever measurements. The large magnitude and slow kinetics of the contraction can be explained by an intermixed gold-sulphur layer that has recently been identified crystallographically. Our results illustrate the importance of crystal edges and grain boundaries in interface chemistry and have broad implications for the application of thiol-based SAMs, ranging from nanomechanical sensors to coating technologies.

  16. Faceting of curved surfaces using the curvature coordinate system

    DEFF Research Database (Denmark)

    Almegaard, Henrik

    2008-01-01

    In many situations, a curved surface has to be approximated by a facetted surface, i.e., as a network with planar meshes. Most often this is done by triangulation of the surface. Points are chosen on the surface and the points are connected by straight lines so that these lines make a network...... this is by tangent faceting. Tangent points are chosen on the surface and the tangent planes at these points are connected along lines of intersection so that these lines make a network with planar meshes and so that no normal to the curved surface intersect more than one facet. The result is a faceted surface...... of triangular meshes and so that no normal to the curved surface intersect more than one mesh/facet. The result is a faceted surface, with vertices, edges and triangular facets. But faceting a curved surface can also be done using planes as the basic geometrical element instead of points. One way of doing...

  17. Large-System Analysis of Joint User Selection and Vector Precoding with Zero-Forcing Transmit Beamforming for MIMO Broadcast Channels

    CERN Document Server

    Takeuchi, Keigo; Kawabata, Tsutomu

    2012-01-01

    Multiple-input multiple-output (MIMO) broadcast channels (BCs) (MIMO-BCs) with perfect channel state information (CSI) at the transmitter are considered. As joint user selection (US) and vector precoding (VP) (US-VP) with zero-forcing transmit beamforming (ZF-BF), US and continuous VP (CVP) (US-CVP) and data-dependent US (DD-US) are investigated. The replica method, developed in statistical physics, is used to analyze the energy penalties for the two US-VP schemes in the large-system limit, where the number of users, the number of selected users, and the number of transmit antennas tend to infinity with their ratios kept constant. Four observations are obtained in the large-system limit: First, the assumptions of replica symmetry (RS) and 1-step replica symmetry breaking (1RSB) for DD-US can provide acceptable approximations for low and moderate system loads, respectively. Secondly, DD-US outperforms CVP with random US in terms of the energy penalty for low-to-moderate system loads. Thirdly, the asymptotic en...

  18. The Influence of Oblique Angle Forced Exercise in Surgically Destabilized Stifle Joints Is Synergistic with Bone, but Antagonistic with Cartilage in an Ovine Model of Osteoarthritis.

    Science.gov (United States)

    Hill, Rachel J; Mason, Holly M; Yeip, Gavin; Merchant, Samer S; Olsen, Aaron L; Stott, Rusty D; Van Wettere, Arnaud J; Bressel, Eadric; Mason, Jeffrey B

    2017-01-01

    Large animal models of osteoarthritis are a necessary testing ground for FDA approval of human medicine applications. Sheep models have advantages over other available large animals, but development and progression of osteoarthritis in sheep is exceedingly slow, which handicaps progress in development of potential treatments. We combined oblique angle forced exercise to increase stress on the stifle, with surgical destabilization to hasten the development of osteoarthritis in ewes. Methods for early detection of clinical signs included radiography, urine, and serum biomarker assays and gait analysis and ex vivo we used microcomputed tomography and macroscopic joint analysis. Our model was able to produce clinically detectable signs of osteoarthritis in a relatively short period (14 weeks). Changes in bone were highly correlated between microcomputed tomography and radiographic analysis and changes in cartilage correlated well between urinary glycosaminoglycan levels and serum aggrecanase analyses. Exercise improved the negative effects of destabilization in bone but exacerbated the negative effects of destabilization in cartilage. These observations suggest that we may need to consider treatments for bone and cartilage separately. These results represent an improved large animal model of osteoarthritis with rapid onset of disease and superior detection of bone and soft tissue changes.

  19. Comprehensive drilling of the C1-2 facets to achieve direct posterior reduction in irreducible atlantoaxial dislocation.

    Science.gov (United States)

    Salunke, Pravin; Sahoo, Sushanta K; Deepak, Arsikere N; Ghuman, Mandeep S; Khandelwal, Niranjan K

    2015-09-01

    The cause of irreducibility in irreducible atlantoaxial dislocation (AAD) appears to be the orientation of the C1-2 facets. The current management strategies for irreducible AAD are directed at removing the cause of irreducibility followed by fusion, rather than transoral decompression and posterior fusion. The technique described in this paper addresses C1-2 facet mobilization by facetectomies to aid intraoperative manipulation. Using this technique, reduction was achieved in 19 patients with congenital irreducible AAD treated between January 2011 and December 2013. The C1-2 joints were studied preoperatively, and particular attention was paid to the facet orientation. Intraoperatively, oblique C1-2 joints were opened widely, and extensive drilling of the facets was performed to make them close to flat and parallel to each other, converting an irreducible AAD to a reducible one. Anomalous vertebral arteries (VAs) were addressed appropriately. Further reduction was then achieved after vertical distraction and joint manipulation. Adequate facet drilling was achieved in all but 2 patients, due to VA injury in 1 patient and an acute sagittal angle operated on 2 years previously in the other patient. Complete reduction could be achieved in 17 patients and partial in the remaining 2. All patients showed clinical improvement. Two patients showed partial redislocation due to graft subsidence. The fusion rates were excellent. Comprehensive drilling of the C1-2 facets appears to be a logical and effective technique for achieving direct posterior reduction in irreducible AAD. The extensive drilling makes large surfaces raw, increasing fusion rates.

  20. Influence of higher order modes on angled-facet amplifiers

    DEFF Research Database (Denmark)

    Wang, Z.; Mikkelsen, B.; Stubkjær, Kristian

    1991-01-01

    The influence of the first-order mode on the residual reflectivity of angled-facet amplifiers is analyzed. For a 7 degrees angled-facet ridge waveguide amplifier with a single-layer antireflective (AR) coating, a gain ripple lower than 1-dB at 25-dB gain can be obtained independent...... by increasing the facet angles to 10 degrees...

  1. /facet: A browser for heterogeneous semantic web repositories

    NARCIS (Netherlands)

    Hildebrand, M.; Ossenbruggen, J.R. van; Hardman, L.

    2006-01-01

    Facet browsing has become popular as a user friendly interface to data repositories. We extend facet browsing of Semantic Web data in four ways. First, users are able to select and navigate through facets of resources of any type and to make selections based on properties of other, semantically rela

  2. “Decoding” angiogenesis: new facets controlling endothelial cell behavior

    Directory of Open Access Journals (Sweden)

    Massimo Mattia Santoro

    2016-07-01

    Full Text Available Angiogenesis, the formation of new blood vessels, is a unique and crucial biological process occurring during both development and adulthood. A better understanding of the mechanisms that regulates such process is mandatory to intervene in pathophysiological conditions. Here we highlight some recent argument on new players that are critical in endothelial cells, by summarizing novel discoveries that regulate notorious vascular pathways such as Vascular Endothelial Growth Factor (VEGF, Notch and Planar Cell Polarity, and by discussing more recent findings that put metabolism, redox signaling and hemodynamic forces as novel unforeseen facets in angiogenesis. These new aspects, that critically regulate angiogenesis and vascular homeostasis in health and diseased, represent unforeseen new ground to develop anti-angiogenic therapies.

  3. Non-Radiative Step Facets in Semiconductor Nanowires.

    Science.gov (United States)

    Sanchez, Ana M; Zhang, Yunyan; Tait, Edward W; Hine, Nicholas D M; Liu, Huiyun; Beanland, Richard

    2017-03-24

    One of the main advantages of nanowires for functional applications is their high perfection, which results from surface image forces that act on line defects such as dislocations, rendering them unstable and driving them out of the crystal. Here we show that there is a class of linear defects that are stable in nanowires, with no long-range strain field or dislocation character. In zinc-blende semiconductors, they take the form of Ʃ3 (112) facets with heights constrained to be a multiple of three {111} monolayers. Density functional theory calculations show that they act as non-radiative recombination centres and have deleterious effects on nanowire properties. We present experimental observations of these defects on twin boundaries and twins that terminate inside GaAsP nanowires and find that they are indeed always multiples of three monolayers in height. Strategies to use the three-monolayer rule during growth to prevent their formation are discussed.

  4. Zeroing In on Mindfulness Facets: Similarities, Validity, and Dimensionality across Three Independent Measures.

    Science.gov (United States)

    Siegling, Alex B; Petrides, K V

    2016-01-01

    The field of mindfulness has seen a proliferation of psychometric measures, characterised by differences in operationalisation and conceptualisation. To illuminate the scope of, and offer insights into, the diversity apparent in the burgeoning literature, two distinct samples were used to examine the similarities, validity, and dimensionality of mindfulness facets and subscales across three independent measures: the Five Facet Mindfulness Questionnaire (FFMQ), Philadelphia Mindfulness Scale (PHLMS), and Toronto Mindfulness Scale (TMS). Results revealed problematic associations of FFMQ Observe with the other FFMQ facets and supported a four-factor structure (omitting this facet), while disputing the originally envisaged five-factor model; thus, solidifying a pattern in the literature. Results also confirmed the bidimensional nature of the PHLMS and TMS subscales, respectively. A joint Confirmatory Factor Analysis showed that PHLMS Acceptance could be assimilated within the FFMQ's four-factor model (as a distinct factor). The study offers a way of understanding interrelationships between the available mindfulness scales, so as to help practitioners and researchers make a more informed choice when conceptualising and operationalising mindfulness.

  5. A Faceted Query Engine Applied to Archaeology

    Directory of Open Access Journals (Sweden)

    Kenneth A. Ross

    2007-04-01

    Full Text Available In this article we present the Faceted Query Engine, a system developed at Columbia University under the aegis of the inter-disciplinary project Computational Tools for Modeling, Visualizing and Analyzing Historic and Archaeological Sites. Our system is based on novel Database Systems research that has been published in Computer Science venues (Ross and Janevski, 2004 and Ross et al., 2005. The goal of this article is to introduce our system to the target user audience - the archaeology community. We demonstrate the use of the Faceted Query Engine on a previously unpublished dataset: the Thulamela (South Africa collection. This dataset is comprised of iron-age finds from the Thulamela site at the Kruger National Park. Our project is the first to systematically compile and classify this dataset. We also use a larger dataset, a collection of ancient Egyptian artifacts from the Memphis site (Giddy,1999, to demonstrate some of the features of our system.

  6. Facets of Emotional Clarity and Suspiciousness.

    Science.gov (United States)

    Boden, Matthew Tyler; Berenbaum, Howard

    2012-09-01

    In a college student sample, we explored the relations between individual differences in facets of emotional clarity and suspiciousness. Previous theory and research has treated emotional clarity as a one-dimensional construct. Boden and Berenbaum (2011) proposed that a second facet of emotional clarity, source awareness (a general understanding of the cause of their emotions), could be distinguished from type awareness (a general understanding of the type of emotions [anger, fear] experienced). We found that source and type awareness were incrementally, inversely associated with suspiciousness when statistically accounting for the extent to which emotions are attended to, and gender. Additionally, source awareness significantly predicted suspiciousness after accounting for anger, anxious arousal, and social anxiety, whereas type awareness did not. Findings are consistent with the hypothesis that, among individuals with low source and type awareness, suspicious beliefs are formed to make sense of and explain emotional arousal.

  7. Neurophysiological markers of multiple facets of impulsivity.

    Science.gov (United States)

    Neal, Lauren B; Gable, Philip A

    2016-03-01

    Human behavior is influenced by three core personality systems: approach, avoidance, and supervisory control. The supervisory control system is inversely related to impulsivity. Although past research has related some aspects of impulsivity to frontal hemispheric asymmetry, impulsivity as a multi-faceted construct has not been studied in relation with frontal asymmetry. In addition, past work has potentially confounded impulsivity with approach-motivation. In the current study, greater relative left frontal activity was related to multiple facets of impulsivity: negative urgency, lack of premeditation, lack of perseverance, and positive urgency. Regressing both positive and negative urgency on frontal asymmetry revealed that approach-related positive urgency related to greater left frontal activity, but withdrawal-related negative urgency marginally related to greater right frontal activity. These results suggest that impulsivity, independent of affective valence, relates to greater left frontal activity. When controlling for trait approach motivation, the relationship between impulsivity and left frontal activity is unchanged.

  8. Effect of Retrograde Reaming for Tibiotalocalcaneal Arthrodesis on Subtalar Joint Destruction: A Cadaveric Study.

    Science.gov (United States)

    Lowe, Jason A; Routh, Lucas K; Leary, Jeffrey T; Buzhardt, Paul C

    2016-01-01

    Recent published data have suggested successful union of subtalar and tibiotalar joints without formal debridement during tibiotalocalcaneal (TTC) fusion procedures. Although previous studies have reported on the importance of the proper guidewire starting point and trajectory to obtain appropriate hindfoot alignment for successful fusion, to our knowledge, no studies have quantified the amount of articular damage to the subtalar joint with retrograde reaming. We hypothesized that reaming would destroy >50% of the posterior facet of the subtalar joint. The bilateral lower extremities of 5 cadavers were obtained and the subtalar joints exposed. Retrograde TTC nail guidewires were inserted, and a 12-mm reamer was passed through the subtalar and ankle joints. Pre- and postreaming images of the subtalar joint were obtained to compare the amount of joint destruction after reaming. We found an average of 5.89% articular destruction of the talar posterior facet and an average of 4.01% articular destruction of the posterior facet of the calcaneus. No damage to the middle facets of the subtalar joint was observed. TTC nailing is a successful procedure for ankle and subtalar joint fusion. Published studies have reported successful subtalar union using TTC nailing without formal open debridement of the subtalar joint, preserving the soft tissue envelope. TTC nail insertion using a 12-mm reamer will destroy 5.89% and 4.01% of the respective talar and calcaneal posterior facets of the subtalar joint. Copyright © 2016 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  9. FACET: The New User Facility at SLAC

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, C.I.; Decker, F.J.; Erikson, R.; Hast, C.; Hogan, M.J.; Iverson, R.; Li, S.Z.; Nosochkov, Y.; Phinney, N.; Sheppard, J.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC; Seryi, A.; /Oxford U., JAI; Wittmer, W.; /Michigan State U.

    2011-12-13

    FACET (Facility for Advanced Accelerator and Experimental Tests) is a new User Facility at SLAC National Accelerator Laboratory. Its high power electron and positron beams make it a unique facility, ideal for beam-driven Plasma Wakefield Acceleration studies. The first 2 km of the SLAC linac produce 23 GeV, 3.2 nC electron and positron beams with short bunch lengths of 20 {mu}m. A final focusing system can produce beam spots 10 {mu}m wide. User-aided Commissioning took place in summer 2011 and FACET will formally come online in early 2012. We present the User Facility, the current features, planned upgrades and the opportunities for further experiments. Accelerators are our primary tool for discovering the fundamental laws to the universe. Each new frontier we probe requires a new, more powerful method. Accelerators are therefore increasing in size and cost. The future of this field requires new accelerating techniques that can reach the high energies required over shorter distances. New concepts for high gradient acceleration include utilizing the wakes in plasma and dielectric and metallic structures. FACET was built to provide a test bed for novel accelerating concepts with its high charge and highly compressed beams. As a test facility unlike any other, it has also attracted groups interested in beam diagnostic techniques and terahertz studies. The first phase of the construction was completed in May 2011. Beam commissioning began in June and was interleaved with the installation of five experiments. Users were invited to aid with the commissioning for the month of August during which time experimental hardware and software were checked out and some first measurements were taken. FACET is currently in the process of becoming a Department of Energy User Facility for High Energy Physics.

  10. Studying the various facets of emotional aging

    OpenAIRE

    2014-01-01

    To study emotional aging is to study a very multi-faceted concept. In particular, the study of emotion and aging covers a wide range of topics. Taking a closer look, domains of functioning can be differentiated such as pertaining to the experiential nature of emotion or its regulation, as well as social-cognitive processes associated with the perception of emotion in others or emotion-related attention and memory retrieval. Importantly, evidence over the last two decades suggests that not all...

  11. Kinetics of faceting of crystals in growth, etching, and equilibrium

    Science.gov (United States)

    Vlachos, D. G.; Schmidt, L. D.; Aris, R.

    1993-03-01

    The faceting of crystals in equilibrium with the gas phase and also during crystal growth and etching conditions is studied using the Monte Carlo method. The dynamics of the transformation of unstable crystallographic orientations into hill and valley structures and the spatial patterns that develop are examined as functions of surface temperature, crystallographic orientation, and strength of interatomic potential for two transport processes: adsorption-desorption and surface diffusion. The results are compared with the continuum theory for facet formation. Thermodynamically unstable orientations break into hill and valley structures, and faceting exhibits three time regimes: disordering, facet nucleation, and coarsening of small facets to large facets. Faceting is accelerated as temperature increases, but thermal roughening can occur at high temperatures. Surface diffusion is the dominant mechanism at short times and small facets but adsorption-desorption becomes important at long times and large facets. Growth and etching promote faceting for conditions close to equilibrium but induce kinetic roughening for conditions far from equilibrium. Simultaneous irreversible growth and etching conditions with fast surface diffusion result in enhanced faceting.

  12. Joint Force Quarterly. Issue 36

    Science.gov (United States)

    2004-12-01

    units that are regionally based. Their location should depend on pop - ulation mass. CBRNE weapons are most effective when used in heavily populated...strik- ingly symmetrical and historically surreal way to 106 JFQ / issue thirty-six Iraqi counterterrorism soldiers searching for weapons. U .S . M...territory presented their own pop - ulation statistics based on nationality. However, in the Balkans a single disputed territory might actually contain

  13. Joint Force Quarterly. Issue 39

    Science.gov (United States)

    2005-10-01

    Merrick E. Krause, USAF Director of NDU Press Editor Colonel Debra Taylor, USA Deputy Director of NDU Press Managing Editor Calvin B. Kelley George C...contracted in times of drought or seasonal change, [and] some of us were periodi- cally becoming them.”4 This process is depicted in the Bible , when

  14. Joint Force Quarterly. Issue 35

    Science.gov (United States)

    2004-10-01

    ol e) in Mexico and Canada. This approach will ad- dress existing shortcomings and provide compre- hensive responses to threats such as smallpox , which...scenario, the effects of a terrorist attack using smallpox encompassed a multistate region and rapidly overwhelmed the Federal, state, and local...added, “It will be useful for us to generate enough activity so that the North Koreans begin to wonder what those crazy [Americans] are doing or are

  15. Improving personality facet scores with multidimensional computer adaptive testing

    DEFF Research Database (Denmark)

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A W

    2013-01-01

    Narrowly defined personality facet scores are commonly reported and used for making decisions in clinical and organizational settings. Although these facets are typically related, scoring is usually carried out for a single facet at a time. This method can be ineffective and time consuming when...... personality tests contain many highly correlated facets. This article investigates the possibility of increasing the precision of the NEO PI-R facet scores by scoring items with multidimensional item response theory and by efficiently administering and scoring items with multidimensional computer adaptive...... testing (MCAT). The increase in the precision of personality facet scores is obtained from exploiting the correlations between the facets. Results indicate that the NEO PI-R could be substantially shorter without attenuating precision when the MCAT methodology is used. Furthermore, the study shows...

  16. Porter’s five forces reconsideration: Model of joint MBA programmes and schools’ fusion in the industry of Management Education as a counter point of competitive environment model : COMMUNICATION POUR LA BIENNALE 2015 « COOPERER » Identifiant : N° 448

    OpenAIRE

    NGUYEN, Thi Thu Tra

    2015-01-01

    International audience; In the scope of our doctoral research, business education is considered as an industry where business schools act as firms. Our thesis focuses on the strategic management field, with aims to explore how schools revisit their MBA curricula. Within this framework, joint and merged MBA programmes have been analysed as a counter point of Porter’s five forces (1980): rivalry among competitors, entry barriers, substitutions’ threats, buyers’ and suppliers’ bargaining power. ...

  17. Pressure distribution in the humeroradial joint and force transmission to the capitellum during rotation of the forearm: effects of the Sauvé-Kapandji procedure and incision of the interosseous membrane.

    Science.gov (United States)

    Ofuchi, S; Takahashi, K; Yamagata, M; Rokkaku, T; Moriya, H; Hara, T

    2001-01-01

    A biomechanical study was undertaken, using four fresh cadaveric arms, to evaluate the changes in pressure distribution in the humeroradial joint (H-R joint) during rotation of the forearm before and after the Sauvé-Kapandji procedure (S-K procedure) and also after incision of the interosseous membrane (IOM) following the S-K procedure. The pressure distribution was measured with a pressure-sensitive conductive rubber sensor while the forearm was rotated. Force transmitted to the capitellum was calculated from the measured pressure. In the intact specimens, pressure was concentrated on the medial side of the capitellum in pronation and on the posterolateral side in supination. The pattern of change after the S-K procedure and that after incision of the IOM following the S-K procedure were almost the same as that in the intact forearm. Although the force transmitted to the capitellum increased after the S-K procedure, there were no significant differences between the forces before and after the S-K procedure. However, the force increased significantly after incision of the IOM following the S-K procedure when the forearm was supinated more than 35 degrees, and it was concentrated on the posterior side of the capitellum. The IOM seemed to have an important axial load-bearing function in the forearm position supinated more than 35 degrees. The S-K procedure in patients suffering from distal radioulnar joint disorders with IOM injury is likely to induce H-R joint osteoarthritis, so it should be avoided in these patients.

  18. Porter’s five forces reconsideration: Model of joint MBA programmes and schools’ fusion in the industry of Management Education as a counter point of competitive environment model : COMMUNICATION POUR LA BIENNALE 2015 « COOPERER » Identifiant : N° 448

    OpenAIRE

    NGUYEN, Thi Thu Tra

    2015-01-01

    International audience; In the scope of our doctoral research, business education is considered as an industry where business schools act as firms. Our thesis focuses on the strategic management field, with aims to explore how schools revisit their MBA curricula. Within this framework, joint and merged MBA programmes have been analysed as a counter point of Porter’s five forces (1980): rivalry among competitors, entry barriers, substitutions’ threats, buyers’ and suppliers’ bargaining power. ...

  19. Jointness for the Rest of Us: Reforming Joint Professional Development

    Science.gov (United States)

    2016-06-10

    34Joint Force Development Vision: Adapting to New and Future Realities." JFQ: Joint Force Quarterly, no. 64 (2012): 150 (emphasis added). 7...create opportunities for professional improvement and career progression.7 The Corps concept envisioned education, training, and rotation...opportunities for entry level through senior executives. The report concluded that in order to achieve this goal, DOD career civilians, like their military

  20. Jointness for the Rest of Us: Reforming Joint Professional Development

    Science.gov (United States)

    2016-06-10

    where service capabilities are combined to maximize effectiveness while minimizing vulnerabilities. However, despite the passage of thirty years...34Joint Force Development Vision: Adapting to New and Future Realities." JFQ: Joint Force Quarterly, no. 64 (2012): 150 (emphasis added). 7...create opportunities for professional improvement and career progression.7 The Corps concept envisioned education, training, and rotation

  1. Faceted to non-faceted transition of solid-liquid interface in binary alloys

    Energy Technology Data Exchange (ETDEWEB)

    Yumoto, H.; Hasiguti, R.R.; Kaneko, T.

    1987-03-01

    Jackson's theory on the interfacial roughening transition of pure materials is extended to that of AB binary alloys. In this model, the concept of quasi-dangling bonds is introduced. The bonds are produced by the difference between the number of the interfacial component of nearest neighbors of the A atom and that of the B atom. The roughening temperatures calculated from this model coincide with the faceted - non-faceted transition temperatures obtained experimentally by Miller and Chadwick and by the present authors.

  2. Intra-theater Air Mobility and Theater Distribution for the Joint Force Commander: Is the United States Central Command Model the Best

    Science.gov (United States)

    2010-06-01

    Major, U.S. Air Force, “Leveraging ITIL to Govern AOC...Weaver, Major, U.S. Air Force, “Leveraging ITIL to Govern AOC Information Technology,” Master’s Thesis, Air Force Institute of Technology, December 2005...quoted in Robert V. Weaver, Major, U.S. Air Force, “Leveraging ITIL to Govern AOC Information Technology,” Master’s Thesis, Air Force

  3. FIRO-B: factors and facets.

    Science.gov (United States)

    Macrosson, W D

    2000-02-01

    10 FIRO-B intercorrelation matrices were factor analysed; one matrix was derived from new FIRO-B data, all the other matrices were found in the literature. The correlation matrices were also subjected to meta-analysis. The findings suggested that the four FIRO-B scales associated with Inclusion and Affection are facets of the ubiquitous interpersonal superfactor, Nurturance, but the two FIRO-B Control scales each express an orthogonal construct both of which relate to the super-factor, Dominance.

  4. Multiquark hadrons. A new facet of QCD

    Energy Technology Data Exchange (ETDEWEB)

    Ali, Ahmed

    2016-05-15

    I review some selected aspects of the phenomenology of multiquark states discovered in high energy experiments. They have four valence quarks (called tetraquarks) and two of them are found to have five valence quarks (called pentaquarks), extending the conventional hadron spectrum which consists of quark-antiquark (q anti q) mesons and qqq baryons. Multiquark states represent a new facet of QCD and their dynamics is both challenging and currently poorly understood. I discuss various approaches put forward to accommodate them, with emphasis on the diquark model.

  5. Multiquark Hadrons - A New Facet of QCD

    CERN Document Server

    Ali, Ahmed

    2016-01-01

    I review some selected aspects of the phenomenology of multiquark states discovered in high energy experiments. They have four valence quarks (called tetraquarks) and two of them are found to have five valence quarks (called pentaquarks), extending the conventional hadron spectrum which consists of quark-antiquark $(q\\bar{q})$ mesons and $qqq$ baryons. Multiquark states represent a new facet of QCD and their dynamics is both challenging and currently poorly understood. I discuss various approaches put forward to accommodate them, with emphasis on the diquark model.

  6. FACETS -- Infrastructure for Integrated Fusion Modeling

    Science.gov (United States)

    Shasharina, Svetlana; Cary, John; Carlsson, Johan; Hakim, Ammar; Kruger, Scott; Miah, Mahmood; Pletzer, Alexander; Vadlamani, Srinath; Wade-Stein, David; Balay, Satish; McInnes, Lois; Zhang, Hong; Candy, Jeff; Fahey, Mark; Cohen, Ron; Epperly, Tom; Rognlien, Tom; Estep, Don; Pankin, Alexei; Malony, Allen; Morris, Alan; Shende, Sameer; Indireshkumar, Keshavamurthy; McCune, Douglas; Pigarov, Alexander

    2009-11-01

    It is desirable that an infrastructure for integrated fusion modeling has support for: legacy and new components used interchangeably; consistent management of components lifecycle; allocating parallel resources consistent with the nature of participating components and the problem scope; components written in multiple programming languages; composition of sequentially and concurrently executing components respecting dependencies; tight and loose coupling of components; testing and validation of separate and integrated components; and use of multiple platforms from desktops to LCFs. In this poster we will describe the status of the FACETS with respect to these features.

  7. Control to Facet for Polynomial Systems

    DEFF Research Database (Denmark)

    Sloth, Christoffer; Wisniewski, Rafael

    2014-01-01

    for the controller design are solved by searching for polynomials in Bernstein form. This allows the controller design problem to be formulated as a linear programming problem. Examples are provided that demonstrate the efficiency of the method for designing controls for polynomial systems.......This paper presents a solution to the control to facet problem for arbitrary polynomial vector fields defined on simplices. The novelty of the work is to use Bernstein coefficients of polynomials for determining certificates of positivity. Specifically, the constraints that are set up...

  8. Radiohumeral stability to forced translation

    DEFF Research Database (Denmark)

    Jensen, Steen Lund; Olsen, Bo Sanderhoff; Seki, Atsuhito

    2002-01-01

    Radiohumeral stability to forced translation was experimentally analyzed in 8 osteocartilaginous joint preparations. The joints were dislocated in 8 centrifugal directions at 12 different combinations of joint flexion and rotation while a constant joint compression force of 23 N was applied....... Stability was measured as the maximum resistance to translation. On average, the specimens could resist a transverse force of 16.4 N (range, 13.0-19.1 N). Stability was greater in some directions than in others. Rotating the joint changed the direction at which stability was greatest, whereas joint flexion...

  9. Subtalar Joint Distraction Arthrodesis to Correct Calcaneal Valgus in Pediatric Patients with Tarsal Coalition: A Case Series.

    Science.gov (United States)

    Schwartz, Jaclyn M; Kihm, Carl A; Camasta, Craig A

    2015-01-01

    Subtalar joint middle facet coalitions commonly present in children who have a painful, rigid, pes planovalgus foot type. The middle facet coalition allows rearfoot forces to be distributed medially through the coalition, and this can result in arthritis or lateral tarsal wedging. The senior author has used a wedged bone graft distraction subtalar joint arthrodesis to correct calcaneal valgus and restore the talar height in these patients. The tight, press-fit nature of the tricortical iliac crest allograft provides stability and can negate the need for internal fixation. We retrospectively reviewed 9 pediatric subtalar joint distraction arthrodesis procedures performed on 8 patients during a 6-year period. All patients began weightbearing at 6 weeks after surgery. All patients had osseous union, and no complications developed that required a second surgery. The clinical outcomes, assessed at a mean of 25.5 (range, 6.3 to 75.8) months postoperatively, were satisfactory. The mean American Orthopaedic Foot and Ankle Society score was 90.1 (range, 79 to 94), on a 94-point scale. The wedged distraction arthrodesis technique has not been previously described for correction of pediatric patients with lateral tarsal wedging, but it is an effective option and yields successful outcomes. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  10. Pre-Service Physics Teachers' Content Knowledge of Electric and Magnetic Field Concepts: Conceptual Facets and Their Balance

    Science.gov (United States)

    Nousiainen, Maija; Koponen, Ismo T.

    2017-01-01

    The concepts of electricity and magnetism in physics are complex and demanding to learn because their meaning builds through several different phenomenological areas. Each of the phenomenological areas adds a certain facet of the meaning of the concept. All standard physics textbooks discuss at least 1) force, 2) energy and work, and 3) electric…

  11. Cleaved laser facets on free-standing InGaN LD membrane created by laser lift-off and structural characterisation of the membrane

    Science.gov (United States)

    Zilan, Li; Xiaodong, Hu; Zhixin, Qin; Tongjun, Yu; Ruijuan, Nie; Min, Lu; Qian, Ren; Bei, Zhang; Zhijian, Yang; Weihua, Chen; Zhizhong, Chen; Hua, Yang; Guoyi, Zhang

    2004-09-01

    Cleaved laser facets on free-standing InGaN laser diode membrane created by laser lift-off were fabricated and studied. Cleaved laser facets on GaN on sapphire have been compared with those on free-standing laser membrane. Atomic force microscopy and scanning electron microscopy results show that the cleaved laser facets on free-standing laser membrane are much smoother than those on sapphire. Transmission electron microscopy images show that no significant crystal quality degradation has been introduced during the laser lift-off process.

  12. Morphometric analysis of the cervical facets and the feasibility, safety, and effectiveness of Goel inter-facet spacer distraction technique

    Directory of Open Access Journals (Sweden)

    Abhidha Shah

    2014-01-01

    Full Text Available Aim: Quantitative anatomy of the facets of the sub-axial cervical spine was performed. The purpose of the evaluation was to determine the feasibility of insertion of Goel inter-facetal articular spacers in the sub-axial cervical spine. Only few studies detailing the morphometry of the facets are available in the literature. Materials and Methods: Ten cervical vertebrae from C3 to C7 with a total of 20 facets were evaluated by the author. The anatomic parameters studied were the height, width, thickness, shape, orientation, and inclination of each of the superior and inferior facets. The alterations in a number of intervertebral segmental distances were measured before and after spacer insertion. The distance of the inferior facet from the foramen tranversarium, spinal canal, and neural foramina was measured to assess safety of spacer insertion with respect to the vertebral artery and neural structures. Results: The height, width and thickness of the superior facets from C3 to C7 ranged from 6 to 12 mm, 8 to 12 mm, and 2.5 to 6 mm, respectively. The inferior facets had an average height of 10.5 mm, average width of 11.2 mm and average thickness of 3.5 mm. The inclination of the superior facets with respect to the transverse plane ranged from 22° to 45° and that of the inferior facets ranged from 29° to 53°. The distance of the anterior margin of the inferior facet from the posterior border of the foramen transversium ranged from 5 to 7 mm. This distance was maximum at C3 level, then decreased at C4 and remained constant from C5 to C7. Conclusion: This anatomic evaluation aided in understanding the morphology of the cervical facets and the suitability of the cervical facetal articular cavity for insertion of spacers.

  13. Spontaneous septic arthritis of the lumbar facet caused by methicillin-resistant Staphylococcus aureus in an otherwise healthy adolescent.

    Science.gov (United States)

    Papaliodis, Dean N; Roberts, Timothy T; Richardson, Nicholas G; Lawrence, James B

    2014-07-01

    We report the case of a 16-year-old boy with isolated septic arthritis of a lumbar facet. This rare presentation of an infection in a lumbar facet joint occurred after minor trauma sustained in a football game. Septic arthritis of the spinal facet joint is an uncommon phenomenon. Only 5 cases have been reported in immunocompromised pediatric patients. To our knowledge, no case of septic arthritis in an immunocompetent pediatric patient has been reported. An otherwise healthy 16-year-old boy presented with 4 weeks of escalating back pain after a minor athletics-related trauma. Evaluation showed incapacitating pain, lumbar musculature spasms, and the absence of fever, hemodynamic, or neurologic changes. Laboratory values were within normal limits. Magnetic resonance images showed a fluid collection within the L3-L4 facet and a localized abscess. Computed tomographic-guided aspiration showed methicillin-resistant Staphylococcus aureus infection, for which the patient received 6 weeks of vancomycin with complete resolution of symptoms. Refractory lumbago in an adolescent requires careful evaluation.

  14. Facet-Engineered Surface and Interface Design of Photocatalytic Materials.

    Science.gov (United States)

    Bai, Song; Wang, Lili; Li, Zhengquan; Xiong, Yujie

    2017-01-01

    The facet-engineered surface and interface design for photocatalytic materials has been proven as a versatile approach to enhance their photocatalytic performance. This review article encompasses some recent advances in the facet engineering that has been performed to control the surface of mono-component semiconductor systems and to design the surface and interface structures of multi-component heterostructures toward photocatalytic applications. The review begins with some key points which should receive attention in the facet engineering on photocatalytic materials. We then discuss the synthetic approaches to achieve the facet control associated with the surface and interface design. In the following section, the facet-engineered surface design on mono-component photocatalytic materials is introduced, which forms a basis for the discussion on more complex systems. Subsequently, we elucidate the facet-engineered surface and interface design of multi-component photocatalytic materials. Finally, the existing challenges and future prospects are discussed.

  15. Modeling Reusable and Interoperable Faceted Browsing Systems with Category Theory.

    Science.gov (United States)

    Harris, Daniel R

    2015-08-01

    Faceted browsing has become ubiquitous with modern digital libraries and online search engines, yet the process is still difficult to abstractly model in a manner that supports the development of interoperable and reusable interfaces. We propose category theory as a theoretical foundation for faceted browsing and demonstrate how the interactive process can be mathematically abstracted. Existing efforts in facet modeling are based upon set theory, formal concept analysis, and lightweight ontologies, but in many regards, they are implementations of faceted browsing rather than a specification of the basic, underlying structures and interactions. We will demonstrate that category theory allows us to specify faceted objects and study the relationships and interactions within a faceted browsing system. Implementations can then be constructed through a category-theoretic lens using these models, allowing abstract comparison and communication that naturally support interoperability and reuse.

  16. Foundations of reusable and interoperable facet models using category theory.

    Science.gov (United States)

    Harris, Daniel R

    2016-10-01

    Faceted browsing has become ubiquitous with modern digital libraries and online search engines, yet the process is still difficult to abstractly model in a manner that supports the development of interoperable and reusable interfaces. We propose category theory as a theoretical foundation for faceted browsing and demonstrate how the interactive process can be mathematically abstracted. Existing efforts in facet modeling are based upon set theory, formal concept analysis, and light-weight ontologies, but in many regards, they are implementations of faceted browsing rather than a specification of the basic, underlying structures and interactions. We will demonstrate that category theory allows us to specify faceted objects and study the relationships and interactions within a faceted browsing system. Resulting implementations can then be constructed through a category-theoretic lens using these models, allowing abstract comparison and communication that naturally support interoperability and reuse.

  17. Facets of Dispositional Mindfulness and Health Among College Students.

    Science.gov (United States)

    Bodenlos, Jamie S; Wells, Stephanie Y; Noonan, Marleah; Mayrsohn, Aubreyanne

    2015-10-01

    The purpose of the current study was to examine the relationship between the facets of trait mindfulness with psychological and physical health while controlling for health behaviors in college students. 310 students from a small, private college in the Northeastern United States. Students completed self-report measures, including the Perceived Stress Scale (PSS-14), the Five Facet Mindfulness Questionnaire (FFMQ), Medical Outcomes Short-Form Health Survey (SF-36), and the Rutgers Alcohol Problems Index (RAPI). After controlling for other health behaviors, the observation facet of mindfulness was negatively associated with physical health. Both acting with awareness and nonjudging facets were positively associated with emotional well-being. For social functioning, nonjudging was a significant positive facet for this domain of health. Tailoring mindfulness-based interventions to enhance these facets may be beneficial to young adults.

  18. Usability Studies of Faceted Browsing: A Literature Review

    Directory of Open Access Journals (Sweden)

    Jody Condit Fagan

    2010-06-01

    Full Text Available Faceted browsing is a common feature of new library catalog interfaces. But to what extent does it improve user performance in searching within today’s library catalog systems? This article reviews the literature for user studies involving faceted browsing and user studies of “next-generation” library catalogs that incorporate faceted browsing. Both the results and the methods of these studies are analyzed by asking, What do we currently know about faceted browsing? How can we design better studies of faceted browsing in library catalogs? The article proposes methodological considerations for practicing librarians and provides examples of goals, tasks, and measurements for user studies of faceted browsing in library catalogs.

  19. Preliminary design of large reflectors with flat facets

    Science.gov (United States)

    Agrawal, P. K.; Anderson, M. S.; Card, M. F.

    1981-01-01

    A concept for approximating curved antenna surfaces using flat facets is discussed. A preliminary design technique for determining the size of the reflector surface facets necessary to meet antenna surface accuracy requirements is presented. A proposed large microwave radiometer satellite (MRS) is selected as an application, and the far-field electromagnetic response of a faceted reflector surface is compared with that from a spherical reflector surface.

  20. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    Science.gov (United States)

    Goyal, Amit

    2013-07-09

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  1. Faceted ceramic fibers, tapes or ribbons and epitaxial devices therefrom

    Energy Technology Data Exchange (ETDEWEB)

    Goyal, Amit (Knoxville, TN)

    2012-07-24

    A crystalline article includes a single-crystal ceramic fiber, tape or ribbon. The fiber, tape or ribbon has at least one crystallographic facet along its length, which is generally at least one meter long. In the case of sapphire, the facets are R-plane, M-plane, C-plane or A-plane facets. Epitaxial articles, including superconducting articles, can be formed on the fiber, tape or ribbon.

  2. Ultrasound-guided facet block to low back pain: a case report

    Directory of Open Access Journals (Sweden)

    Ana Ellen Q. Santiago

    2014-07-01

    Full Text Available BACKGROUND: Osteoarthrosis is a common cause of low back pain. The diagnosis is clinical and can be confirmed by imaging studies. Pain treatment and confirmation of diagnosis are made by intra-articular injection of corticosteroid and by local anesthetic use, due to clinical improvement. A direct monitoring of the procedure can be done under fluoroscopy, a classic technique, or else by an ultrasound-guided procedure. CASE REPORT: Female patient, 88 years old, 1.68 m and 72 kg, with facet osteoarthrosis at L2-L3, L3-L4 and L4-L5 for two years. On physical examination, she exhibited pain on lateralization and spinal extension. We opted in favor of an ultrasound-guided facet joint block. A midline spinal longitudinal scan was obtained, with identification of the desired joint space at L3-L4. A 25 G needle was inserted into the skin by the echographic off-plane ultrasound technique. 1 mL of contrast was administered, with confirmation by fluoroscopy. After aspiration of the contrast, 1 mL of solution containing 0.25% bupivacaine hydrochloride and 10 mg of methylprednisolone acetate was injected. Injections into L3-L4, L2-L3 and L1-L2 to the right were applied. CONCLUSIONS: The visualization of the facet joint by ultrasound involves minimal risk, besides reduction of radiation. This option is suitable for a large part of the population. However, fluoroscopy and computed tomography remain as monitoring techniques indicated for patients with specific characteristics, such as obesity, severe degenerative diseases and anatomical malformations, in which the ultrasound technique is still in need of further study.

  3. The functional anatomy of the cricothyroid joint.

    Science.gov (United States)

    Windisch, Gunther; Hammer, Georg Philipp; Prodinger, Peter Michael; Friedrich, Gerhard; Anderhuber, Friedrich

    2010-02-01

    Postoperative long-term treatment problems of male-to-female transsexuals can be caused by the underestimated mobility of the cricothyroid joint. One hundred cadaveric larynges were analysed to reveal the morphological and functional anatomy of the CTJ focusing on possible horizontal and vertical gliding movements. Furthermore, the distance of the cricothyroid space for rotational movements was measured. The articular surface of the cricothyroid joint showed three different possibilities: a well-defined facet (Type 1 61%), no definable facet (Type 2 22%) or a flat surface with or without a tiny protuberance (Type 3 17%). Side different statements and intraindividual differences between male and female specimens were included. These different types affect horizontal and vertical gliding movements, besides rotational movements. The mobility between Type 1 and the others was highly significant (P < 0.001). Regarding different motions in the cricothyroid joint, rotational movements caused significant elongation of the vocal folds, which should be taken into consideration for phonosurgical methods.

  4. Weak layer fracture: facets and depth hoar

    Directory of Open Access Journals (Sweden)

    I. Reiweger

    2013-09-01

    Full Text Available Understanding failure initiation within weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of four samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be observed in detail. Catastrophic failure started due to a shear fracture just above the interface between the depth hoar layer and the underlying crust.

  5. Diagnostics Challenges for FACET-II

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Christine

    2015-10-07

    FACET-II is a prospective user facility at SLAC National Accelerator Laboratory. The facility will focus on high-energy, high-brightness beams and their interaction with plasma and lasers. The accelerator is designed for high-energy-density electron beams with peak currents of approximately 50 kA (potentially 100 kA) that are focused down to below 10x10 micron transverse spot size at an energy of 10 GeV. Subsequent phases of the facility will provide positron beams above 10 kA peak current to the experiment station. Experiments will require well characterised beams; however, the high peak current of the electron beam can lead to material failure in wirescanners, optical transition radiation screens and other instruments critical for measurement or delivery. The radiation environment and space constraints also put additional pressure on diagnostic design.

  6. Problem of Time: Facets and Machian Strategy

    CERN Document Server

    Anderson, Edward

    2013-01-01

    The Problem of Time in Quantum Gravity is that `time' in GR and `time' in ordinary quantum theory are mutually incompatible notions, which is problematic in trying to put these two theories together to form a theory of Quantum Gravity. It has 8 facets, of which I reconceptualize and re-name the following. The Frozen Formalism Problem as Temporal Relationalism, the Thin Sandwich Problem as Configurational Relationalism via Best Matching, the Problem of Observables as the Problem of Beables, the Functional Evolution Problem as the Constraint Closure Problem, and I point out multiplicity of the Global and Multiple-Choice Problems of Time. This article contains a local resolution to the Problem of Time at the conceptual level and which is actually realizable for the relational triangle and minisuperspace models. This resolution is, moreover, Machian, and has three levels: classical, semiclassical and combined semiclassical-histories-records. The current frontiers of this program toward resolution of the Problem o...

  7. Weak layer fracture: facets and depth hoar

    Directory of Open Access Journals (Sweden)

    I. Reiweger

    2013-05-01

    Full Text Available Understanding the fracture behavior of weak snow layers is essential for modeling and predicting dry-snow slab avalanches. We therefore performed laboratory experiments with snow samples containing a weak layer consisting of either faceted crystals or depth hoar. During these experiments the samples were loaded with different loading rates and at various tilt angles until fracture. The strength of the samples decreased with increasing loading rate and increasing tilt angle. Additionally, we took pictures of the side of the samples with a high-speed video camera and calculated the displacement using a particle image velocimetry (PIV algorithm. The fracture process within the weak layer could thus be studied in detail. We found a fracture in shear immediately followed by a collapse of the weak layer.

  8. Explorations in statistics: statistical facets of reproducibility.

    Science.gov (United States)

    Curran-Everett, Douglas

    2016-06-01

    Learning about statistics is a lot like learning about science: the learning is more meaningful if you can actively explore. This eleventh installment of Explorations in Statistics explores statistical facets of reproducibility. If we obtain an experimental result that is scientifically meaningful and statistically unusual, we would like to know that our result reflects a general biological phenomenon that another researcher could reproduce if (s)he repeated our experiment. But more often than not, we may learn this researcher cannot replicate our result. The National Institutes of Health and the Federation of American Societies for Experimental Biology have created training modules and outlined strategies to help improve the reproducibility of research. These particular approaches are necessary, but they are not sufficient. The principles of hypothesis testing and estimation are inherent to the notion of reproducibility in science. If we want to improve the reproducibility of our research, then we need to rethink how we apply fundamental concepts of statistics to our science.

  9. Artificial Dendritic Cells: Multi-faceted Perspectives

    CERN Document Server

    Greensmith, Julie

    2009-01-01

    Dendritic cells are the crime scene investigators of the human immune system. Their function is to correlate potentially anomalous invading entities with observed damage to the body. The detection of such invaders by dendritic cells results in the activation of the adaptive immune system, eventually leading to the removal of the invader from the host body. This mechanism has provided inspiration for the development of a novel bio-inspired algorithm, the Dendritic Cell Algorithm. This algorithm processes information at multiple levels of resolution, resulting in the creation of information granules of variable structure. In this chapter we examine the multi-faceted nature of immunology and how research in this field has shaped the function of the resulting Dendritic Cell Algorithm. A brief overview of the algorithm is given in combination with the details of the processes used for its development. The chapter is concluded with a discussion of the parallels between our understanding of the human immune system a...

  10. 3D Model Optimization of Four-Facet Drill for 3D Drilling Simulation

    Directory of Open Access Journals (Sweden)

    Buranský Ivan

    2016-09-01

    Full Text Available The article is focused on optimization of four-facet drill for 3D drilling numerical modelling. For optimization, the process of reverse engineering by PowerShape software was used. The design of four-facet drill was created in NumrotoPlus software. The modified 3D model of the drill was used in the numerical analysis of cutting forces. Verification of the accuracy of 3D models for reverse engineering was implemented using the colour deviation maps. The CAD model was in the STEP format. For simulation software, 3D model in the STEP format is ideal. STEP is a solid model. Simulation software automatically splits the 3D model into finite elements. The STEP model was therefore more suitable than the STL model.

  11. Highly exposed surface area of {001} facets dominated BiOBr nanosheets with enhanced visible light photocatalytic activity.

    Science.gov (United States)

    Duan, Fang; Wang, Xiaofeng; Tan, Tingting; Chen, Mingqing

    2016-02-17

    Two groups of BiOBr nanosheets with different sizes and similar exposure percentages of {001} facets were selectively synthesized by simple hydrothermal methods. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse reflectance spectroscopy (DRS). The photocatalytic activity was estimated from the degradation of organic pollutants under visible-light irradiation. The results indicated that BiOBr nanosheets with similar exposure percentages of {001} facets but smaller sizes exhibited higher photocatalytic activity. Furthermore, the effects of the size, including the thickness and length, of BiOBr nanosheets were also studied. The results showed that the impact of thickness was more significant than that of length. It was found that reducing the thickness of BiOBr nanosheets can significantly increase the exposed surface areas of {001} facets (S{001}), but not necessarily the exposure percentage of {001} facets. Moreover, in our experiment, the photocatalytic activity of BiOBr nanosheets increased linearly with an increase in S{001} in the range of 0.022 to 0.111 nm(-1). Therefore, the photocatalytic activity of BiOBr nanosheets depended on the exposed surface areas of {001} facets rather than the exposure percentage of {001} facets. The enhancement of the photocatalytic activity of ultrathin BiOBr nanosheets with large exposed surface areas of {001} facets can be mainly ascribed to their enhanced absorption of visible light and improved separation efficiency of charge carriers.

  12. The Position Sense and Muscle Force Sense of the Ankle Joint with Functional Instability%功能性不稳踝关节位置觉和肌肉力觉特征

    Institute of Scientific and Technical Information of China (English)

    张秋霞; 张林; 王国祥; 王国栋

    2012-01-01

    Objective To examine the difference in proprioception of the ankle joint with functional instability through analyzing the joint position sense and force sense, in order to provide the basis for the prevention from and treatment on the sprained ankle. Methods Fourteen males subjects with unilateral functional ankle instability (FAD were enrolled in the study, and other 14 healthy matched-paired subjects were served as controls. The target angle of the ankle passively reposition was set at 5° plantar flexion for measuring joint position sense and the target force of the muscle at 25% maximal voluntary isometric contraction for measuring muscle force sense. 2×2 mixed model ANOVA was used to compare the difference in proprioception between two the groups with and without FAI. Results The VEJPS (variable error of joint position sense) and AEJPS (absolute error of joint position sense) of FAI group were not significantly different from those of the control group (P>0.05) .However, there was significant difference in the RVEFS (relative variable error of force sense) and RAEFS (relative absolute error of force sense) between the two groups (P 0.05).. Conclusion The difference between FAI group and the control group was found not in the joint position sense, but in themuscle force sense. The ability of neuromuscular control for the FAI group was impaired. There was only one subject whose proprioception appeared to be normal.%目的:探讨功能性不稳踝关节的位置觉和肌肉力觉特征及其发生机制,为踝关节损伤防治和康复训练提供依据.方法:选取14名有单侧踝关节功能性不稳的受试者为实验组(FAI组),匹配14名无踝关节伤病的受试者作为对照组.测试受试者踝关节跖屈5°的被动定位并被动复位能力作为踝关节位置觉,计算位置觉的可变误差(VEJPS)和绝对误差(AEJPS).测试受试者踝关节跖屈肌群对25%最大等长峰值力矩值的复制能力作为肌肉力觉,计

  13. Lumbar facet injection for the treatment of chronic piriformis myofascial pain syndrome: 52 case studies

    Directory of Open Access Journals (Sweden)

    Huang JT

    2014-08-01

    Full Text Available Jen-Ting Huang,1 Han-Yu Chen,2 Chang-Zern Hong,2 Ming-Ta Lin,3 Li-Wei Chou,4,5 Hsin-Shui Chen,6,7 Chien-Tsung Tsai,8 Wen-Dien Chang9  1Department of Orthopedic Surgery, Taichung Veterans General Hospital, 2Department of Physical Therapy, Hung-Kuang University, Sha Lu, 3Kuan-Ta Rehabilitation and Pain Clinic, Taichung, Taiwan; 4Department of Physical Medicine and Rehabilitation, China Medical University Hospital, 5School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, Taiwan; 6Department of Rehabilitation Medicine, Bei-Gang Hospital, School of Medicine, China Medical University, Yun-Lin, Taiwan; 7School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan; 8Department of Rehabilitation Medicine, Da-Chien Hospital, Miao-Li City, Taiwan; 9Department of Sports Medicine, China Medical University, Taichung, Taiwan Background and aims: The aim of this study was to demonstrate the effectiveness of lumbar facet joint injection for piriformis myofascial pain syndrome. Methods: Fifty-two patients with chronic myofascial pain in the piriformis muscle each received a lumbar facet injection into the ipsilateral L5–S1 facet joint region, using the multiple insertion technique. Subjective pain intensity, trunk extension range, and lumbar facet signs were measured before, immediately after, and 2 weeks after injection. Thirty-six patients received follow-up for 6 months. Results: Immediately after the injection, 27 patients (51.9% had complete pain subsidence, 19 patients (36.5% had pain reduction to a tolerable level, and only 6 patients (11.5% had no pain relief to a tolerable level. Mean pain intensity was reduced from 7.4±0.9 to 1.6±2.1 after injection (P<0.01. This effectiveness lasted for 2 weeks in 49 patients (94.2%, and lasted for approximately 6 months in 35 (97.2% of 36 patients. The mean range of motion increased from 13.4±6.8 degrees to 22.1±6.0 degrees immediately

  14. Possible burst-like facet growth mode at high temperatures

    Science.gov (United States)

    Lovrić, Davorin; Vučić, Zlatko; Gladić, Jadranko

    2008-07-01

    A decade ago, a burst-like growth mode of c-facets of 4He crystals growing at mK temperatures, characterized by the alternation of time intervals during which the facet does not advance with the intervals of its fast advancement, was found [J.P. Ruutu, P.J. Hakonen, A.V. Babkin, A.Y. Parshin, J.S. Penttilä, J.P. Saramäki, G. Tvalashvili, Phys. Rev. Lett. 76 (1996) 4187]. We investigate the possibility that a similar facet growth mode exists for facets at high growth temperatures. We have applied the digital laser interferometry for monitoring facet kinetics of spherical copper selenide single crystals during their growth at constant volume growth rate around 800 K. Our analysis of directly measured (1 1 1) facet advancement curves has revealed that they consist of time intervals during which the facet does not advance vertically alternating with the time intervals of enhanced growth, resembling the burst-like facet growth mode. The results are discussed in terms of the enhancement of the local supersaturation induced by the existence of nucleation barrier.

  15. Search Interface Design Using Faceted Indexing for Web Resources.

    Science.gov (United States)

    Devadason, Francis; Intaraksa, Neelawat; Patamawongjariya, Pornprapa; Desai, Kavita

    2001-01-01

    Describes an experimental system designed to organize and provide access to Web documents using a faceted pre-coordinate indexing system based on the Deep Structure Indexing System (DSIS) derived from POPSI (Postulate based Permuted Subject Indexing) of Bhattacharyya, and the facet analysis and chain indexing system of Ranganathan. (AEF)

  16. Proximal attrition facets: morphometric, demographic, and aging characteristics.

    Science.gov (United States)

    Sarig, Rachel; Hershkovitz, Israel; Shvalb, Nir; Sella-Tunis, Tatiana; May, Hila; Vardimon, Alexander D

    2014-08-01

    Although interproximal attrition is considered to be limited in modern populations, it has important clinical implications. However, in contrast to occlusal attrition, proximal attrition receives limited scientific attention. The main purpose of the current study was to fill this void. Seven-hundred and sixty-five teeth were collected from 255 skulls of subjects 18-75 yr of age. For each individual, three mandibular teeth (the first and second premolars and the first molar) were examined for proximal attrition facets (PAFs). The results provide detailed information on the size, shape, and location of the facets according to age cohort, gender, and ethnicity. The validity of the method used to measure the facets was also examined. The major findings were as follows: PAFs are usually located on the upper half of the crown proximal aspect; in each tooth, the mesial facet is more lingually positioned and the distal facet is more buccally positioned; the majority of the facets are subrectangular in shape; the size of the facets tends to increase in an anteroposterior direction (from premolars to molars); and facet size and location are age- and sex-dependent and ethnicity-independent. It is our recommendation that dentists bear in mind that interproximal attrition is a dynamic, long-term process and needs to be considered in many clinical scenarios.

  17. A note on clique-web facets for multicut polytopes

    DEFF Research Database (Denmark)

    Sørensen, Michael Malmros

    2002-01-01

    In this note we provide a previously undiscovered necessary condition for the facet-defining property of clique-web inequalities for the multicut polytope. This condition imposes a minimum cardinality requirement on the node set of the clique, thus implying, in general, that clique-web inequalities...... associated with relatively small cliques are not facet-defining for multicut polytopes....

  18. A Note on Clique-Web Facets for Multicut Polytopes

    DEFF Research Database (Denmark)

    Sørensen, Michael Malmros

    2002-01-01

    In this note we provide a previously undiscovered necessary condition for the facet defining property of clique-web inequalities for the multicut polytope. This condition imposes a minimum cardinality requirement on the node set of the clique, thus implying that clique-web inequalities associated...... with relatively small cliques are not facet defining in general for multicut polytopes....

  19. /facet: A Browser for Heterogeneous Semantic Web Repositories

    NARCIS (Netherlands)

    Hildebrand, M.; Ossenbruggen, J.R. van; Hardman, L.

    2006-01-01

    Facet browsing has become popular as a user friendly interface to data repositories. The Semantic Web raises new challenges due to the heterogeneous character of the data. First, users should be able to select and navigate through facets of resources of any type and to make selections based on prope

  20. FacetAtlas: multifaceted visualization for rich text corpora.

    Science.gov (United States)

    Cao, Nan; Sun, Jimeng; Lin, Yu-Ru; Gotz, David; Liu, Shixia; Qu, Huamin

    2010-01-01

    Documents in rich text corpora usually contain multiple facets of information. For example, an article about a specific disease often consists of different facets such as symptom, treatment, cause, diagnosis, prognosis, and prevention. Thus, documents may have different relations based on different facets. Powerful search tools have been developed to help users locate lists of individual documents that are most related to specific keywords. However, there is a lack of effective analysis tools that reveal the multifaceted relations of documents within or cross the document clusters. In this paper, we present FacetAtlas, a multifaceted visualization technique for visually analyzing rich text corpora. FacetAtlas combines search technology with advanced visual analytical tools to convey both global and local patterns simultaneously. We describe several unique aspects of FacetAtlas, including (1) node cliques and multifaceted edges, (2) an optimized density map, and (3) automated opacity pattern enhancement for highlighting visual patterns, (4) interactive context switch between facets. In addition, we demonstrate the power of FacetAtlas through a case study that targets patient education in the health care domain. Our evaluation shows the benefits of this work, especially in support of complex multifaceted data analysis.