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Sample records for activity knee motion

  1. Active knee motion after cruciate ligament rupture. Stereoradiography.

    Science.gov (United States)

    Kärrholm, J; Selvik, G; Elmqvist, L G; Hansson, L I

    1988-04-01

    In 10 patients with an old injury of the anterior cruciate ligament, the three-dimensional movements of the knee joint were studied when the patients flexed their knees. Tibial motions were recorded using roentgen stereophotogrammetric analysis. Internal rotation and adduction of the tibia were reduced in the injured knees when compared with the intact knees; during flexion of the knee joint, the tibial intercondylar eminence occupied a more lateral and posterior position on the injured side. Our results may indicate that the knee joint is continuously exposed to abnormal stresses when the anterior cruciate ligament is torn. PMID:3364185

  2. Ambulatory measurement of knee motion and physical activity: preliminary evaluation of a smart activity monitor

    Directory of Open Access Journals (Sweden)

    Malchau Henrik

    2006-09-01

    Full Text Available Abstract Background There is currently a paucity of devices available for continuous, long-term monitoring of human joint motion. Non-invasive, inexpensive devices capable of recording human activity and joint motion have many applications for medical research. Such a device could be used to quantify range of motion outside the gait laboratory. The purpose of this study was to test the accuracy of the modified Intelligent Device for Energy Expenditure and Activity (IDEEA in measuring knee flexion angles, to detect different physical activities, and to quantify how often healthy subjects use deep knee flexion in the ambulatory setting. Methods We compared Biomotion Laboratory (BML "gold standard" data to simultaneous IDEEA measures of knee motion and gait, step up/down, and stair descent in 5 healthy subjects. In addition, we used a series of choreographed physical activities outside the BML to confirm the IDEEA's ability to accurately measure 7 commonly-performed physical activities. Subjects then continued data collection during ordinary activities outside the gait laboratory. Results Pooled correlations between the BML and IDEEA knee flexion angles were .97 +/- .03 for step up/down, .98 +/- .02 for stair descent, and .98 +/- .01 for gait. In the BML protocol, the IDEEA accurately identified gait, but was less accurate in identifying step up/down and stair descent. During sampling outside the BML, the IDEEA accurately detected walking, running, stair ascent, stair descent, standing, lying, and sitting. On average, subjects flexed their knees >120° for 0.17% of their data collection periods outside the BML. Conclusion The modified IDEEA system is a useful clinical tool for evaluating knee motion and multiple physical activities in the ambulatory setting. These five healthy subjects rarely flexed their knees >120°.

  3. Complementary limb motion estimation for the control of active knee prostheses.

    Science.gov (United States)

    Vallery, Heike; Burgkart, Rainer; Hartmann, Cornelia; Mitternacht, Jürgen; Riener, Robert; Buss, Martin

    2011-02-01

    To restore walking after transfemoral amputation, various actuated exoprostheses have been developed, which control the knee torque actively or via variable damping. In both cases, an important issue is to find the appropriate control that enables user-dominated gait. Recently, we suggested a generic method to deduce intended motion of impaired or amputated limbs from residual human body motion. Based on interjoint coordination in physiological gait, statistical regression is used to estimate missing motion. In a pilot study, this complementary limb motion estimation (CLME) strategy is applied to control an active knee exoprosthesis. A motor-driven prosthetic knee with one degree of freedom has been realized, and one above-knee amputee has used it with CLME. Performed tasks are walking on a treadmill and alternating stair ascent and descent. The subject was able to walk on the treadmill at varying speeds, but needed assistance with the stairs, especially to descend. The promising results with CLME are compared with the subject's performance with her own prosthesis, the C-Leg from Otto Bock.

  4. Older Adults without Radiographic Knee Osteoarthritis: Knee Alignment and Knee Range of Motion

    OpenAIRE

    Lissa Fahlman; Emmeline Sangeorzan; Nimisha Chheda; Daphne Lambright

    2014-01-01

    This study describes knee alignment and active knee range of motion (ROM) in a community-based group of 78-year old adults (n = 143) who did not have radiographic evidence of knee osteoarthritis in either knee (KL 0.001) than women with varus or...

  5. Effects of two different continuous passive motion application protocols on the functional activities of total knee arthroplasty inpatients

    OpenAIRE

    Bakırhan, Serkan; Ünver, Bayram; Karatosun, Vasfi

    2015-01-01

    Objective: The aim of this study was to compare the effects of two different continuous passive motion (CPM) application protocols (low- and high-angle) on the early phase functional activities of total knee arthroplasty inpatients.Methods: The study included 170 patients who underwent primary TKA. While 84 of the TKA patients underwent low-angle CPM application, 86 of the patients underwent high-angle CPM application. The patients’ functional activities were compared using the Iowa Level of ...

  6. EFFECTS OF FATIGUE ON FRONTAL PLANE KNEE MOTION, MUSCLE ACTIVITY, AND GROUND REACTION FORCES IN MEN AND WOMEN DURING LANDING

    Directory of Open Access Journals (Sweden)

    Michael P. Smith

    2009-09-01

    Full Text Available Women tear their Anterior Cruciate Ligament (ACL 2-8 times more frequently than men. Frontal plane knee motion can produce a pathological load in the ACL. During a state of fatigue the muscles surrounding the knee joint may lose the ability to protect the joint during sudden deceleration while landing. The purpose of this study was to investigate the effects of fatigue and gender on frontal plane knee motion, EMG amplitudes, and GRF magnitudes during drop- jump landing. Pretest-posttest comparison group design was used. Twenty-six volunteers (14 women; 12 Men; Mean ± standard deviation age = 24.5 ± 2.7 yrs; height = 1.73 ± 0.09 m; mass = 74.3 ± 11.8 kg participated in the study. Knee frontal plane ranges of motion and positions, ground reaction force peak magnitudes, and surface EMG RMS amplitudes from five lower extremity muscles (vastus medialis, vastus lateralis, medial hamstring, lateral hamstring, and lateral gastrocnemius were obtained during the landing phase of a drop-jump. MANOVA and ANOVA indicated that peak GRF significantly (p < 0.05; 2.50 ± 0.75 BW vs. 2.06 ± 0.93 BW decreased during fatigued landings. No other variables exhibited a fatigue main effect, although there was a significant (p < 0.05 fatigue by gender interaction for the frontal plane range of motion from initial contact to max knee flexion variable. Follow-up analyses failed to reveal significant gender differences at the different levels of fatigue for this variable. Additionally, no variables exhibited a significant gender main effect. Single subject analysis indicated that fatigue significantly altered frontal plane knee motion, peak GRF, and EMG in some subjects and the direction of differences varied by individual. Fatigue altered some aspects of landing performance in both men and women, but there were no gender differences. Additionally, both group and single subject analyses provided valuable but different information about factors representing

  7. [Effectiveness of continuous passive motion after total knee replacement].

    Science.gov (United States)

    Trzeciak, Tomasz; Richter, Magdalena; Ruszkowski, Krzysztof

    2011-01-01

    Continuous passive motion (CPM) is frequently used method in the early post-operative rehabilitation in patients after knee surgery. Aim of this study was to evaluate the effectiveness of CPM after primary total knee arthroplasty. Efficacy was assesed in terms of clinical score and functional recovery. 93 patients (101 knee joints) undergoing total knee replacement were assigned into two groups. The experimental group received continuous passive motion and active exercises. A control group received conventional physical therapy only. CPM was initiated in the first day after surgery, for 120 minutes, starting with 0-40 degrees range of motion, increased as tolerated (mean 10 degrees per day) and maintained during the hospital stay. Outcome measures were those included in Knee Society Score (KSS). Functional recovery was evaluated using WOMAC. All subjects were evaluated once before the surgery and on 10th day postoperatively. Mean clinical score (KSS) at the day 10 was 70 +/- 15 points in the experimental group and 74 +/- 12 in a control group. There were no statistical difference between the two groups for any outcome measures. CPM group mean range of motion was 83 degrees +/- 14 degrees and a group without CPM 77 degrees +/- 21 degrees. KSS functional score was 66 +/- 9 points in the experimental group compared to 62 +/- 7 points in a control group. Subjective estimation of pain level, joint stiffness and function showed no statistical difference between the two groups regarding total and subscale scores. Mean total score was 24 +/- 19 points in the CPM group and 22 +/- 17 in a group without CPM. These findings show that CPM had no significant advantage in terms of improving clinical measurements. However, there was beneficial effect on subjective assessment of pain level, joint stiffness and functional ability.

  8. Does knee motion contribute to feet-in-place balance recovery?

    Science.gov (United States)

    Cheng, Kuangyou B

    2016-06-14

    Although knee motions have been observed at loss of balance, the ankle and hip strategies have remained the focus of past research. The present study aimed to investigate whether knee motions contribute to feet-in-place balance recovery. This was achieved by experimentally monitoring knee motions during recovery from forward falling, and by simulating balance recovery movements with and without knee joint as the main focus of the study. Twelve participants initially held a straight body configuration and were released from different forward leaning positions. Considerable knee motions were observed especially at greater leaning angles. Simulations were performed using 3-segment (feet, shanks+thighs, and head+arms+trunk) and 4-segment (with separate shanks and thighs segments) planar models. Movements were driven by joint torque generators depending on joint angle, angular velocity, and activation level. Optimal joint motions moved the mass center projection to be within the base of support without excessive joint motion. The 3-segment model (without knee motions) generated greater backward linear momentum and had better balance performance, which confirmed the advantage of having only ankle/hip strategies. Knee motions were accompanied with less body angular momentum and a lower body posture, which could be beneficial for posture control and reducing falling impact, respectively.

  9. Reliability of knee joint range of motion and circumference measurements after total knee arthroplasty: does tester experience matter?

    DEFF Research Database (Denmark)

    Jakobsen, Thomas Linding; Christensen, Malene; Christensen, Stine Sommer;

    2010-01-01

    BACKGROUND AND PURPOSE: Two of the most utilized outcome measures to assess knee joint range of motion (ROM) and intra-articular effusion are goniometry and circumference, respectively. Neither goniometry nor circumference of the knee joint have been examined for both intra-tester and inter......-tester in patients with total knee arthroplasty (TKA). The purpose of this study was to determine the intra-tester and inter-tester reliability of active and passive knee joint ROM and circumference in patients with TKA when administered by physiotherapists (testers) with different clinical experience. METHOD......: The design was an intra-tester, inter-tester and intra-day reliability study. Nineteen outpatients (10 females) having received a TKA were examined by an inexperienced and an experienced physiotherapist. Following a standardized protocol, active and passive knee joint ROM and circumference measurements were...

  10. Patella Eversion Reduces Early Knee Range of Motion and Muscle Torque Recovery after Total Knee Arthroplasty: Comparison between Minimally Invasive Total Knee Arthroplasty and Conventional Total Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Tokifumi Majima

    2011-01-01

    Full Text Available We hypothesized that patella eversion during total knee arthroplasty (TKA reduces early return of active knee extension and flexion, quadriceps muscle strength, and postoperative pain. In 100 conventional TKA knees and 100 minimally invasive TKA (MIS TKA knees, we compared knee range of motion (ROM, postoperative pain, and quadriceps muscle strength at 1 day, 4 days, 1 week, 2 weeks, 3 weeks, 4 weeks, 12 weeks, 1 year, and 5 years after surgery. The differences of surgical approach between MIS TKA and conventional TKA of this study are length of skin incision with subcutaneal flap and patella eversion. In MIS TKA, skin incision is shorter than conventional TKA. Furthermore, patella is not everted in MIS TKA procedure. There were no significant differences in preoperative factors. Postoperative improvement of ROM, postoperative muscle strength recovery, and postoperative improvement of visual analog scale were faster in patients with MIS TKA when compared to that in patients with conventional TKA. On the other hand, no significant difference was observed in complication, 5-year clinical results of subjective knee function score, and the postoperative component angle and lower leg alignment. These results indicate that patella eversion may affect muscle strength recovery and postoperative pain.

  11. Factors Influencing Range of Motion after Total Knee Arthroplasty

    OpenAIRE

    H Farahini; Moghtadaei, M; Bagheri, A; Akbarian, E

    2012-01-01

    Background The range of motion after a total knee arthroplasty is an important clinical outcome affecting the life of the patient. The aim of this study was to determine the most important factors influencing the postoperative knee flexion in Tehran, Iran. Methods Between July 2007 and January 2009, on 95 cases of total knee joint replacement (89 patients), who were followed for 1 year postoperatively, the risk factors were assessed. Patient demographics (sex, age, body mass index, previous s...

  12. Knee extension range of motion and self-report physical function in total knee arthroplasty: mediating effects of knee extensor strength

    OpenAIRE

    Pua Yong-Hao; Ong Peck-Hoon; Chong Hwei-Chi; Yeo William; Tan Celia; Lo Ngai-Nung

    2013-01-01

    Abstract Background Knee extensor strength and knee extension range of motion (ROM) are important predictors of physical function in patients with a total knee arthroplasty (TKA). However, the relationship between the two knee measures remains unclear. The purpose of this study was to examine whether changes in knee extensor strength mediate the association between changes in knee extension ROM and self-report physical function. Methods Data from 441 patients with a TKA were collected preoper...

  13. [Recovery from total knee arthroplasty through continuous passive motion].

    Science.gov (United States)

    Sánchez Mayo, B; Rodríguez-Mansilla, J; González Sánchez, B

    2015-01-01

    The purpose of this study was to know the effects of continuous passive mobilization in patients who underwent total knee arthroplasty. A search strategy was developed to retrieve all clinical trials, written in English and/or Spanish, published in the electronic search databases PubMed, Cochrane Library Plus, Dialnet, CSIC and PEDro. The inclusion criteria were: clinical trials published from January 2000 until November 2014 in English or Spanish. Out of 537 clinical trials that were potentially relevant, a total of 12 were included in this review. The evaluation of 1,153 patients shows that there is no significant difference in improving the range of the joint, pain, balance, motion, healing and hospital stay using continuous passive mobilization against the regular physiotherapy treatment for total knee arthroplasty. The application of continuous passive mobilization in the long-term does not provide any benefit in terms of the breadth of the range of the joint, pain and improvement of standing and motion in comparison with conventional postoperative physiotherapy treatment in total knee arthroplasty. In the short term an improvement is obtained in the range of joint motion in knee flexion. PMID:26486536

  14. Canonical active Brownian motion

    OpenAIRE

    Gluck, Alexander; Huffel, Helmuth; Ilijic, Sasa

    2008-01-01

    Active Brownian motion is the complex motion of active Brownian particles. They are active in the sense that they can transform their internal energy into energy of motion and thus create complex motion patterns. Theories of active Brownian motion so far imposed couplings between the internal energy and the kinetic energy of the system. We investigate how this idea can be naturally taken further to include also couplings to the potential energy, which finally leads to a general theory of cano...

  15. Knee extension range of motion and self-report physical function in total knee arthroplasty: mediating effects of knee extensor strength

    Directory of Open Access Journals (Sweden)

    Pua Yong-Hao

    2013-01-01

    Full Text Available Abstract Background Knee extensor strength and knee extension range of motion (ROM are important predictors of physical function in patients with a total knee arthroplasty (TKA. However, the relationship between the two knee measures remains unclear. The purpose of this study was to examine whether changes in knee extensor strength mediate the association between changes in knee extension ROM and self-report physical function. Methods Data from 441 patients with a TKA were collected preoperatively and 6 months postoperatively. Self-report measure of physical function was assessed by the Short Form 36 (SF-36 questionnaire. Knee extensor strength was measured by handheld dynamometry and knee extension ROM by goniometry. A bootstrapped cross product of coefficients approach was used to evaluate mediation effects. Results Mediation analyses, adjusted for clinicodemographic measures, revealed that the association between changes in knee extension ROM and SF-36 physical function was mediated by changes in knee extensor strength. Conclusions In patients with TKA, knee extensor strength mediated the influence of knee extension ROM on physical function. These results suggest that interventions to improve the range of knee extension may be useful in improving knee extensor performance.

  16. Active knee joint flexibility and sports activity

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders; Vestergaard, E;

    1999-01-01

    was significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly...

  17. Dynamic Finite Element Analysis of Mobile Bearing Type Knee Prosthesis under Deep Flexional Motion

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    Mohd Afzan Mohd Anuar

    2014-01-01

    Full Text Available The primary objective of this study is to distinguish between mobile bearing and fixed bearing posterior stabilized knee prostheses in the mechanics performance using the finite element simulation. Quantifying the relative mechanics attributes and survivorship between the mobile bearing and the fixed bearing prosthesis remains in investigation among researchers. In the present study, 3-dimensional computational model of a clinically used mobile bearing PS type knee prosthesis was utilized to develop a finite element and dynamic simulation model. Combination of displacement and force driven knee motion was adapted to simulate a flexion motion from 0° to 135° with neutral, 10°, and 20° internal tibial rotation to represent deep knee bending. Introduction of the secondary moving articulation in the mobile bearing knee prosthesis has been found to maintain relatively low shear stress during deep knee motion with tibial rotation.

  18. Clinically assessed mediolateral knee motion: impact on gait

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Creaby, Mark W; Simic, Milena;

    2011-01-01

    Mediolateral knee movement can be assessed visually with clinical tests. A knee-medial-to-foot position is associated with an increased risk of knee injuries and pathologies. However, the implications of such findings on daily tasks are not well understood. The aim of this study was to investigate...... if a knee-medial-to-foot position assessed during a clinical test was associated with altered hip and knee joint kinematics and knee joint kinetics during gait compared with those with a knee-over-foot position....

  19. Auricular Acupressure for Managing Postoperative Pain and Knee Motion in Patients with Total Knee Replacement: A Randomized Sham Control Study

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    Ling-hua Chang

    2012-01-01

    Full Text Available Background. Postoperative pain management remains a significant challenge for all healthcare providers. A randomized controlled trial was conducted to examine the adjuvant effects of auricular acupressure on relieving postoperative pain and improving the passive range of motion in patients with total knee replacement (TKR. Method. Sixty-two patients who had undergone a TKR were randomly assigned to the acupressure group and the sham control group. The intervention was delivered three times a day for 3 days. A visual analog scale (VAS and the Short-Form McGill Pain Questionnaire were used to assess pain intensity. Pain medication consumption was recorded, and the knee motion was measured using a goniometer. Results. The patients experienced a moderately severe level of pain postoperatively (VAS 58.66 ± 20.35 while being on the routine PCA. No differences were found in pain scores between the groups at all points. However, analgesic drug usage in the acupressure group patients was significantly lower than in the sham control group (<0.05, controlling for BMI, age, and pain score. On the 3rd day after surgery, the passive knee motion in the acupressure group patients was significantly better than in the sham control group patients (<0.05, controlling for BMI. Conclusion. The application of auricular acupressure at specific therapeutic points significantly reduces the opioid analgesia requirement and improves the knee motion in patients with TKR.

  20. Prevalence of knee instability in relation to sports activity

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders; Hansen, Thorsten Ingemann

    2001-01-01

    The objective was to estimate the prevalence of knee instability among active athletes and to investigate potential associations to type, amount and duration of sports participation. Based on a questionnaire, 339 athletes provided information about different features of occupation, sports activity...... and knee instability. The 12-month period prevalence of knee instability and constant or recurrent knee instability, and absence from sport and absence from work due to knee instability, was 22%, 14%, 5% and 1%, respectively. Knee instability as such, and constant or recurrent knee instability were found...... to be positively associated with female gender and different features of occupational work. In conclusion, knee instability is a commonly reported phenomenon among active athletes. It was found to be independent of the type and the amount of sports activity but highly dependent on female gender, type and amount...

  1. Reflex responses to combined hip and knee motion in human chronic spinal cord injury

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    Ming Wu, PhD

    2010-04-01

    Full Text Available The relative contributions of hip and knee proprioceptors to the origination of extensor spasms were examined in 11 subjects with chronic spinal cord injury (SCI. Ramp and hold extension and combined hip and knee oscillation movements were imposed to the right leg while the ankle was held in a static position by a custom-designed robot. Isometric joint torques of the hip, knee, and ankle and surface electromyograms (EMGs from seven leg muscles were recorded following controlled hip and knee extension. A stereotypical torque response consisting of hip flexion, knee extension, and ankle plantar flexion was observed following hip and knee perturbations. Further, the hip or knee joint posture modulated the spastic reflexes triggered by the extension movement of the other joint, with larger responses observed with the hip and knee extended. In addition, combined hip and knee oscillation movements were imposed to one leg with four different phasing conditions. The phasing between the hip and knee modulated the reflex activity triggered by hip and knee oscillations. The EMG patterns of the spastic reflexes were generally consistent with muscle timing during locomotion in human SCI. This knowledge may help identify rehabilitation strategies that produce functional movements in human SCI.

  2. Auricular Acupressure for Managing Postoperative Pain and Knee Motion in Patients with Total Knee Replacement: A Randomized Sham Control Study

    OpenAIRE

    Ling-hua Chang; Chung-Hua Hsu; Gwo-Ping Jong; Shungtai Ho; Shiow-luan Tsay; Kuan-Chia Lin

    2012-01-01

    Background. Postoperative pain management remains a significant challenge for all healthcare providers. A randomized controlled trial was conducted to examine the adjuvant effects of auricular acupressure on relieving postoperative pain and improving the passive range of motion in patients with total knee replacement (TKR). Method. Sixty-two patients who had undergone a TKR were randomly assigned to the acupressure group and the sham control group. The intervention was delivered three times a...

  3. Motion analysis of knee joint using dynamic volume images

    Science.gov (United States)

    Haneishi, Hideaki; Kohno, Takahiro; Suzuki, Masahiko; Moriya, Hideshige; Mori, Sin-ichiro; Endo, Masahiro

    2006-03-01

    Acquisition and analysis of three-dimensional movement of knee joint is desired in orthopedic surgery. We have developed two methods to obtain dynamic volume images of knee joint. One is a 2D/3D registration method combining a bi-plane dynamic X-ray fluoroscopy and a static three-dimensional CT, the other is a method using so-called 4D-CT that uses a cone-beam and a wide 2D detector. In this paper, we present two analyses of knee joint movement obtained by these methods: (1) transition of the nearest points between femur and tibia (2) principal component analysis (PCA) of six parameters representing the three dimensional movement of knee. As a preprocessing for the analysis, at first the femur and tibia regions are extracted from volume data at each time frame and then the registration of the tibia between different frames by an affine transformation consisting of rotation and translation are performed. The same transformation is applied femur as well. Using those image data, the movement of femur relative to tibia can be analyzed. Six movement parameters of femur consisting of three translation parameters and three rotation parameters are obtained from those images. In the analysis (1), axis of each bone is first found and then the flexion angle of the knee joint is calculated. For each flexion angle, the minimum distance between femur and tibia and the location giving the minimum distance are found in both lateral condyle and medial condyle. As a result, it was observed that the movement of lateral condyle is larger than medial condyle. In the analysis (2), it was found that the movement of the knee can be represented by the first three principal components with precision of 99.58% and those three components seem to strongly relate to three major movements of femur in the knee bend known in orthopedic surgery.

  4. Effectiveness of prolonged use of continuous passive motion (CPM as an adjunct to physiotherapy following total knee arthroplasty: Design of a randomised controlled trial [ISRCTN85759656

    Directory of Open Access Journals (Sweden)

    Geesink Ruud JT

    2006-02-01

    Full Text Available Abstract Background Adequate and intensive rehabilitation is an important requirement for successful Total Knee Arthroplasty. The primary focus of early rehabilitation is ambulation of patients and regaining range of motion in the knee. Although research suggests that Continuous Passive Motion should be implemented in the first rehabilitation phase following surgery, there is substantial debate about the duration of each session and the total period of CPM application and. A Cochrane review on this topic concluded that short-term use of CPM leads to greater short-term range of motion. It also suggested, however, that future research should concentrate on the treatment period during which CPM should be administered. Methods In a randomised controlled trial we intend to investigate the efficacy of prolonged use of a continuous passive motion (CPM device in the home situation as an adjunct to standardised physical therapy. The experimental treatment is compared to standardised physical therapy, in patients with osteoarthritis of the knee undergoing Total Knee Arthroplasty (TKA. Efficacy will be assessed in terms of faster improvements in range of motion and functional recovery. Seventy patients with knee osteoarthritis undergoing TKA and experiencing early postoperative flexion impairment (less than 80° of knee flexion at the time of discharge will be randomised over two treatment groups, a usual care group and an experimental group The experimental group will receive CPM + physiotherapy for 17 consecutive days after surgery, whereas the usual care group will receive the same treatment during the in-hospital phase (i.e. about four days, followed by physical therapy alone (usual care in the first two weeks after hospital discharge. From 18 days to three months after discharge, both groups will receive standardised PT. The primary focus of rehabilitation will be functional recovery (e.g. ambulation and regaining range of motion (ROM in the knee

  5. Patients' reasons for electing to undergo total knee arthroplasty impact post-operative pain severity and range of motion.

    Science.gov (United States)

    Cremeans-Smith, Julie K; Boarts, Jessica M; Greene, Kenneth; Delahanty, Douglas L

    2009-06-01

    The present study examines the reasons cited by 103 patients for their electing to undergo total knee arthroplastic surgery and the relationship between these reasons and their post-operative pain and range of motion. Results suggest that individuals who describe different reasons for undergoing surgery vary in their post-operative recovery. Specifically, patients who cite pain as the reason they are undergoing surgery report greater levels of pain during the early post-operative period. In contrast, patients who describe goals of regaining mobility or a specific activity as their reason for undergoing surgery achieve a greater range of motion during early post-operative physical therapy. Individuals who express avoidance goals for undergoing total knee arthroplasty report more severe post-operative pain at 1 and 3 months following surgery compared to patients who express approach goals. Interventions targeted towards patients reporting pre-operative pain or avoidance goals may decrease subsequent post-operative pain and increase mobility.

  6. Motion analysis of Chinese normal knees during gait based on a novel portable system.

    Science.gov (United States)

    Zhang, Yu; Yao, Zilong; Wang, Shaobai; Huang, Wenhan; Ma, Limin; Huang, Huayang; Xia, Hong

    2015-03-01

    Normative tibiofemoral data of Chinese or Asian subjects during gait is rarely reported. This study is aimed at investigating the six-degree-of-freedom (6DOF) knee kinematics of adult Chinese during gait, based on a novel portable system. Twenty-eight healthy Chinese subjects (56 knees) were studied during their treadmill gaits. A set of optical marker clusters were attached to the thighs and shanks of each subject, who was tracked by an optical joint kinematics measurement system. Knee landmarks were initially digitized with respect to the marker cluster sets to determine the local coordinate systems for calculation of 6DOF knee joint kinematics. The range of motion (ROM) in 6DOF and 5 kinematic parameters were calculated and compared between bilateral knees and genders. We discovered that knee rotations, as well as motion in proximodistal and mediolateral translations, showed similar patterns in flexion and extension. However, the anteroposterior translations did not show a clear pattern. The results of ROM in 6DOF obtained in this study are comparable with those reported in existing literature. No statistical difference was found between left and right knees either in the ROMs or in the 5 kinematic parameters. However, the ROM in the mediolateral direction during gait was found to be higher in men than women (P=0.014). In addition, the femurs of female subjects rotated more internally than the femurs of male during the stance phase (P=0.011). We concluded that normal Chinese knees exhibited distinct gait patterns, except for anteroposterior motion. Women and men exhibit different axial rotations and mediolateral translation patterns during their treadmill gait.

  7. Range of joint motion and disability in patients with osteoarthritis of the knee or hip.

    NARCIS (Netherlands)

    Steultjens, M.P.M.; Dekker, J.; Baar, M.E. van; Oostendorp, R.A.B.; Bijlsma, J.W.J.

    2000-01-01

    OBJECTIVE: To establish the relationships between the range of joint motion (ROM) and disability in patients with osteoarthritis (OA) of the knee or hip. Two related issues were addressed: (1) the inter-relationships between ROMs of joint actions, and (2) the relationship between ROM and disability.

  8. THE ROLE OF KNEE POSITIONING AND RANGE-OF-MOTION ON THE CLOSED-STANCE FOREHAND TENNIS SWING

    Directory of Open Access Journals (Sweden)

    Steven M. Nesbit

    2008-03-01

    Full Text Available This paper discusses the role of knee positioning and range-of- motion on the closed-stance forehand tennis swing. The analyses of tennis swing mechanics were performed using a computer model comprised of a full-body model of a human and an inertial model of a racket. The model was driven by subject forehand swings (16 female college-level subjects recorded with a high-speed digital motion analysis system. The study discovered that both initial knee positioning and range-of-motion were positively related to racket velocity and characteristic of more skilled players. The direct effects of knee positioning and range-of-motion on racket movement are minimal, however there are several indirect biomechanical effects on the forehand motion such as movement of the body mass center, work of the knee, hip and back joints, and the angular range-of-motion of the hips and torso. Some of these indirect effects were related to racket velocity and characteristic of more skilled players. Factors that influenced knee positioning and range-of-motion include years of playing, amount of coaching, and body style. Efforts to both increase and restrict the knee movements of the subjects resulted in substantially lower racket velocities (and other detrimental biomechanical effects implying that there may be optimal knee positions and range-of-motion for a given subject. The most skilled subject exhibited a high degree of consistency of knee positioning and range-of-motion. This subject adjusted for varying ball height through modified initial knee positioning while maintaining fairly constant ranges-of-motion

  9. Safety of Early Application of Continuous Passive Motion in Patients after Total Knee Arthroplasty

    Institute of Scientific and Technical Information of China (English)

    顾晓园; 陈文红; 张中南; 励建安

    2002-01-01

    ObjectiveThis research aimed to study the effect of early application of continuous passive motion (CPM) on the drainage volume of knee joints post total knee arthroplasty (TKA).MethodsThe drainage volume was measured 1 h before,during and after CPM on the day and next day of the operation.ResultsThere was no significant difference in the drainage volume before,during and after CPM(P >0.05).ConclusionEarly application of CPM is safe for TKA patients.``

  10. Safety of Early Application of Continuous Passive Motion in Patients after Total Knee Arthroplasty

    Institute of Scientific and Technical Information of China (English)

    顾晓园; 陈文红; 等

    2002-01-01

    Objective This research aimed to study the effect of early application of continuous passive motion(CPM) on the drainage volume of knee joints post total knee arthroplasty (TKA).Methods The drainage volume was measured 1h before,during and after CPM on the day and next day of the operation.Results There was no significant difference in the drainage volume before,during and after CPM(P>0.05).Conclusion Early application of CPM is safe for TKA patients.

  11. [Measurement of the knee range of motion: standard goniometer or smartphone?].

    Science.gov (United States)

    Rwakabayiza, Sylvia; Pereira, Luis Carlos; Lécureux, Estelle; Jolles-Haeberli, Brigitte

    2013-12-18

    Universal standard goniometer is an essential tool to measure articulations' range of motion (ROM). In this time of technological advances and increasing use of smartphones, new measurement's tools appear as specific smartphone applications. This article compares the iOS application "Knee Goniometer" with universal standard goniometer to assess knee ROM. To our knowledge, this is the first study that uses a goniometer application in a clinical context. The purpose of this study is to determine if this application could be used in clinical practice. PMID:24693586

  12. The use of Continuous Passive Motion (CPM) in the rehabilitation of patients after total knee arthroplasty.

    Science.gov (United States)

    Synder, Marek; Kozłowski, Piotr; Drobniewski, Marek; Grzegorzewski, Andrzej; Głowacka, Anna

    2004-06-30

    Background. Total knee alloplasty (TKA) is standard treatment for advanced gonarthrosis. Proper rehabilitation of the operated joint and the patient is essential in order to achieve a satisfactory functional outcome. The aim of our study was to compare rehabilitation methods used for patients recovering from TKA in the Orthopedic Clinic of the Medical University in Łódź, Poland. Material and methods. We studied 186 patients operated for advanced gonarthrosis, ranging in age from 29 to 80 (average 65.8), who had received 197 endoprotheses. From 1986 to 1989 the rehabilitation program included isometric exercises of the muscles in the operated joint, general fitness exercises in bed, and passive exercises of the knee conducted by a physiotherapist. The average stay during this period was 19.7 +/- 2.5 days. In 1989, continuous passive motion (CPM) using an electric rail was introduced to the rehabilitation program. Results. Thanks to the earlier additional flexibility of the operated joint, active exercises and weight bearing on the operated limb could be accelerated. The patients left the Clinic 2 weeks after surgery (13.6 +/- 2.5 days). The change in the rehabilitation program produced a statistically significant increase in the average range of flexion in the operated joint (p = 0.000001) in a significantly shorter time (p = 0.0000). Conclusion. Introducing CPM to the rehabilitation of TKA patients accelerates their progress and reduces hospitalization time, which improves the patients' emotional comfort and enables a faster return to an active life in society. PMID:17675995

  13. Validity and inter-rater reliability of medio-lateral knee motion observed during a single-limb mini squat

    DEFF Research Database (Denmark)

    Ageberg, Eva; Bennell, Kim L; Hunt, Michael A;

    2010-01-01

    Muscle function may influence the risk of knee injury and outcomes following injury. Clinical tests, such as a single-limb mini squat, resemble conditions of daily life and are easy to administer. Fewer squats per 30 seconds indicate poorer function. However, the quality of movement, such as the...... medio-lateral knee motion may also be important. The aim was to validate an observational clinical test of assessing the medio-lateral knee motion, using a three-dimensional (3-D) motion analysis system. In addition, the inter-rater reliability was evaluated....

  14. [Sport activity after hip and knee arthroplasty].

    Science.gov (United States)

    Keren, Amit; Berkovich, Yaron; Berkovitch, Yaron; Soudry, Michael

    2013-11-01

    Joint arthroplasty is one of the commonest surgical procedures in orthopedic surgery. In recent years there was an increase in the number of procedures, patient satisfaction and implant survival. Originally, these operations were designed for old patients in order to relieve pain and to enable ambulation. Over the past few years, these operations have become common in younger patients which desire to return to activity, including sports activities. The importance of physical activity is a well known fact. In recent years it became clear that with the proper physical activity the outcomes of the operations are better. There are several types of arthroplasty. Many factors influence the outcome of the operation apart from the post-surgery physical activity. These factors include patient factors, surgical technique and type of arthroplasty. This review summarizes the recommendations for sports activities after hip and knee arthroplasties. These activities are evaluated according to surgeons' recommendations, stress applied on the implant and long term outcomes. The recommended sports activities after joint arthroplasties are walking, swimming and cycling. Soccer, basketball and jogging are not advised. Tennis, downhill skiing and horse riding are recommended with previous experience. There are many more sports activities that patients can participate in, and it is important that the patient discuss the different options prior to the operation. Since these operations are so common, many non-orthopedic physicians encounter these patients in their practice. They should be acquainted with the recommendations for sports activities and encourage them. PMID:24416822

  15. A parallel framework for the FE-based simulation of knee joint motion.

    Science.gov (United States)

    Wawro, Martin; Fathi-Torbaghan, Madjid

    2004-08-01

    We present an object-oriented framework for the finite-element (FE)-based simulation of the human knee joint motion. The FE model of the knee joint is acquired from the patients in vivo by using magnetic resonance imaging. The MRI images are converted into a three-dimensional model and finally an all-hexahedral mesh for the FE analysis is generated. The simulation environment uses nonlinear finite-element analysis (FEA) and is capable of handling contact of the model to handle the complex rolling/sliding motion of the knee joint. The software strictly follows object-oriented concepts of software engineering in order to guarantee maximum extensibility and maintainability. The final goal of this work-in-progress is the creation of a computer-based biomechanical model of the knee joint which can be used in a variety of applications, ranging from prosthesis design and treatment planning (e.g., optimal reconstruction of ruptured ligaments) over surgical simulation to impact computations in crashworthiness simulations.

  16. Knee joint secondary motion accuracy improved by quaternion-based optimizer with bony landmark constraints.

    Science.gov (United States)

    Wang, Hongsheng; Zheng, Naiqaun Nigel

    2010-12-01

    Skin marker-based motion analysis has been widely used in biomechanical studies and clinical applications. Unfortunately, the accuracy of knee joint secondary motions is largely limited by the nonrigidity nature of human body segments. Numerous studies have investigated the characteristics of soft tissue movement. Utilizing these characteristics, we may improve the accuracy of knee joint motion measurement. An optimizer was developed by incorporating the soft tissue movement patterns at special bony landmarks into constraint functions. Bony landmark constraints were assigned to the skin markers at femur epicondyles, tibial plateau edges, and tibial tuberosity in a motion analysis algorithm by limiting their allowed position space relative to the underlying bone. The rotation matrix was represented by quaternion, and the constrained optimization problem was solved by Fletcher's version of the Levenberg-Marquardt optimization technique. The algorithm was validated by using motion data from both skin-based markers and bone-mounted markers attached to fresh cadavers. By comparing the results with the ground truth bone motion generated from the bone-mounted markers, the new algorithm had a significantly higher accuracy (root-mean-square (RMS) error: 0.7 ± 0.1 deg in axial rotation and 0.4 ± 0.1 deg in varus-valgus) in estimating the knee joint secondary rotations than algorithms without bony landmark constraints (RMS error: 1.7 ± 0.4 deg in axial rotation and 0.7 ± 0.1 deg in varus-valgus). Also, it predicts a more accurate medial-lateral translation (RMS error: 0.4 ± 0.1 mm) than the conventional techniques (RMS error: 1.2 ± 0.2 mm). The new algorithm, using bony landmark constrains, estimates more accurate secondary rotations and medial-lateral translation of the underlying bone.

  17. Designing for scale: development of the ReMotion Knee for global emerging markets.

    Science.gov (United States)

    Hamner, Samuel R; Narayan, Vinesh G; Donaldson, Krista M

    2013-09-01

    Amputees living in developing countries have a profound need for affordable and reliable lower limb prosthetic devices. The World Health Organization estimates there are approximately 30 million amputees living in low-income countries, with up to 95% lacking access to prosthetic devices. Effective prosthetics can significantly affect the lives of these amputees by increasing opportunity for employment and providing improvements to long-term health and well-being. However, current solutions are inadequate: state-of-the-art solutions from the US and Europe are cost-prohibitive, while low-cost devices have been challenged by poor quality and/or unreliable performance, and have yet to achieve large scale impact. The introduction of new devices is hampered by the lack of a cohesive prosthetics industry in low-income areas; the current network of low-cost prosthetic clinics is informal and loosely organized with significant disparities in geography, patient volume and demographics, device procurement, clinical and logistical infrastructure, and funding. At D-Rev (Design Revolution) we are creating the ReMotion Knee, which is an affordable polycentric prosthetic knee joint that performs on par with devices in more industrialized regions, like the US and Europe. As of September 2012, over 4200 amputees have been fitted with the initial version of the ReMotion Knee through a partnership with the JaipurFoot Organization, with an 79% compliance rate after 2 years. We are currently scaling production of the ReMotion Knee using centralized manufacturing and distribution to serve the existing clinics in low-income countries and increase the availability of devices for amputees without access to appropriate care. At D-Rev, we develop products that target these customers through economically-sustainable models and provide a measurable impact in the lives of the world's amputees. PMID:23525749

  18. Designing for scale: development of the ReMotion Knee for global emerging markets.

    Science.gov (United States)

    Hamner, Samuel R; Narayan, Vinesh G; Donaldson, Krista M

    2013-09-01

    Amputees living in developing countries have a profound need for affordable and reliable lower limb prosthetic devices. The World Health Organization estimates there are approximately 30 million amputees living in low-income countries, with up to 95% lacking access to prosthetic devices. Effective prosthetics can significantly affect the lives of these amputees by increasing opportunity for employment and providing improvements to long-term health and well-being. However, current solutions are inadequate: state-of-the-art solutions from the US and Europe are cost-prohibitive, while low-cost devices have been challenged by poor quality and/or unreliable performance, and have yet to achieve large scale impact. The introduction of new devices is hampered by the lack of a cohesive prosthetics industry in low-income areas; the current network of low-cost prosthetic clinics is informal and loosely organized with significant disparities in geography, patient volume and demographics, device procurement, clinical and logistical infrastructure, and funding. At D-Rev (Design Revolution) we are creating the ReMotion Knee, which is an affordable polycentric prosthetic knee joint that performs on par with devices in more industrialized regions, like the US and Europe. As of September 2012, over 4200 amputees have been fitted with the initial version of the ReMotion Knee through a partnership with the JaipurFoot Organization, with an 79% compliance rate after 2 years. We are currently scaling production of the ReMotion Knee using centralized manufacturing and distribution to serve the existing clinics in low-income countries and increase the availability of devices for amputees without access to appropriate care. At D-Rev, we develop products that target these customers through economically-sustainable models and provide a measurable impact in the lives of the world's amputees.

  19. Effects of Group-Based Exercise on Range of Motion, Muscle Strength, Functional Ability, and Pain During the Acute Phase After Total Knee Arthroplasty: A Controlled Clinical Trial.

    Science.gov (United States)

    Hiyama, Yoshinori; Kamitani, Tsukasa; Wada, Osamu; Mizuno, Kiyonori; Yamada, Minoru

    2016-09-01

    Study Design Prospective observational study including a historical control group. Background The extent to which group-based exercise (G-EXE) improves knee range of motion (ROM), quadriceps strength, and gait ability is similar to that of individualized exercise (I-EXE) at 6 weeks and 8 months after total knee arthroplasty (TKA). However, the benefits of G-EXE for patients during the acute recovery phase after TKA remain unclear. Objective To determine the effects of G-EXE during the acute recovery phase after TKA on knee ROM, quadriceps strength, functional ability, and knee pain. Methods Two hundred thirty-one patients participated in G-EXE in addition to regular ambulation and activities-of-daily-living exercises twice daily during the hospital stay. Outcomes were compared to those of a retrospectively identified, historical control group (I-EXE group [n = 206]) that included patients who performed exercises identical to those performed by the G-EXE group. The outcomes included knee ROM, quadriceps strength, pain intensity, and timed up-and-go test score at 1 month before surgery and at discharge. Analyses were adjusted for age, body mass index, sex, length of hospital stay, and preoperative values. Results Changes in ROM of knee flexion and extension (PSports Phys Ther 2016;46(9):742-748. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6409. PMID:27494052

  20. Daily Spousal Influence on Physical Activity in Knee Osteoarthritis

    Science.gov (United States)

    Martire, Lynn M.; Stephens, Mary Ann Parris; Mogle, Jacqueline; Schulz, Richard; Brach, Jennifer; Keefe, Francis J.

    2012-01-01

    Background Physical activity is critical for the management of knee osteoarthritis, and the spouse may play a role in encouraging or discouraging physical activity. Purpose To examine four types of spousal influence—spouses' daily activity, autonomy support, pressure, and persuasion--on the daily physical activity of adults living with knee osteoarthritis. Methods A total of 141 couples reported their daily experiences for 22 days using a handheld computer, and wore an accelerometer to measure moderate activity and steps. Results Spouses' autonomy support for patient physical activity, as well as their own level of activity, was concurrently associated with patients' greater daily moderate activity and steps. In addition, on days when male patients perceived that spouses exerted more pressure to be active, they spent less time in moderate activity. Conclusions Couple-oriented interventions for knee osteoarthritis should target physical activity in both partners and spousal strategies for helping patients stay active. PMID:23161472

  1. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H;

    2012-01-01

    contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0-90°). RESULTS: When comparing...... muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric...... the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (p

  2. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H;

    2012-01-01

    contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0-90°). RESULTS: When comparing...... the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (p<0.01) in RF and VM...... elastic tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different...

  3. Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees.

    Science.gov (United States)

    Tienen, T G; Buma, P; Scholten, J G F; van Kampen, A; Veth, R P H; Verdonschot, N

    2005-05-01

    The objective of this study was to validate an in vitro human cadaver knee-joint model for the evaluation of the meniscal movement during knee-joint flexion. The question was whether our model showed comparable meniscal displacements to those found in earlier meniscal movement studies in vivo. Furthermore, we determined the influence of tibial torque on the meniscal displacement during knee-joint flexion. Three tantalum beads were inserted in the medial meniscus of six human-cadaver joints. The knee joints were placed and loaded in a loading apparatus, and the movements of the beads were determined by means of RSA during knee-joint flexion and extension with and without internal tibial (IT) and external tibial (ET) torque. During flexion without tibial torque, all menisci moved in posterior and lateral direction. The anterior horn showed significantly greater excursions than the posterior horn in both posterior and lateral direction. Internal tibial torque caused an anterior displacement of the pathway on the tibial plateau. External tibial torque caused a posterior displacement of the pathway. External tibial torque restricted the meniscal displacement during the first 30 degrees of knee-joint flexion. The displacements of the meniscus in this experiment were similar to the displacements described in the in vivo MRI studies. Furthermore, the application of tibial torque confirmed the relative immobility of the posterior horn of the meniscus. During external tibial torque, the posterior displacement of the pathway on the tibial plateau during the first 30 degrees of flexion might be restricted by the attached knee-joint capsule or the femoral condyle. This model revealed representative meniscal displacements during simple knee-joint flexion and also during the outer limits of passive knee-joint motion.

  4. Effectiveness of prolonged use of continuous passive motion (CPM, as an adjunct to physiotherapy, after total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Geesink Ruud JT

    2008-04-01

    Full Text Available Abstract Background Adequate and intensive rehabilitation is an important requirement for successful total knee arthroplasty. Although research suggests that Continuous Passive Motion (CPM should be implemented in the first rehabilitation phase after surgery, there is substantial debate about the duration of each session and the total period of CPM application. A Cochrane review on this topic concluded that short-term use of CPM leads to greater short-term range of motion. It also suggested, however, that future research should concentrate on the treatment period during which CPM should be administered. Methods In a randomised controlled trial we investigated the effectiveness of prolonged CPM use in the home situation as an adjunct to standardised PT. Efficacy was assessed in terms of faster improvements in range of motion (RoM and functional recovery, measured at the end of the active treatment period, 17 days after surgery. Sixty patients with knee osteoarthritis undergoing TKA and experiencing early postoperative flexion impairment were randomised over two treatment groups. The experimental group received CPM + PT for 17 consecutive days after surgery, whereas the usual care group received the same treatment during the in-hospital phase (i.e. about four days, followed by PT alone (usual care in the first two weeks after hospital discharge. From 18 days to three months after surgery, both groups received standardised PT. The primary focus of rehabilitation was functional recovery (e.g. ambulation and regaining RoM in the knee. Results Prolonged use of CPM slightly improved short-term RoM in patients with limited RoM at the time of discharge after total knee arthroplasty when added to a semi-standard PT programme. Assessment at 6 weeks and three months after surgery found no long-term effects of this intervention Neither did we detect functional benefits of the improved RoM at any of the outcome assessments. Conclusion Although results

  5. Evaluation Of Patellar Tracking During Knee Range Of Motion In Patients With Patellar Lateralization And Normal Subjects

    Directory of Open Access Journals (Sweden)

    Goharpei S

    2004-08-01

    Full Text Available Background: Patellofemoral joint disorders are the most common cause of anterior knee pain in patients who referred to orthopedic clinics. Patellar lateralization cause anterior knee pain due to weakness of vastus medialis oblique muscle or tightness of lateral structures like lateral retinaculum or iliotibial band muscle. Materials and Methods: For evaluation of this abnormality, plane radiography, CT scan and MRI are useful. In plane radiography only one view in a single joint position can be obtained, because of that it is not a good method to detect abnormal tracking during knee range of motion. The purpose of this study was to evaluate patellar tracking by kinematics MRI during five serial degrees of knee range of motion (40, 30, 20, 10, 0 degrees in 30 patients with patellar lateralization and 10 normal subjects, aged 18-30 years. Results and Conclusion: tistical analysis showed that in patients group, patella had the most stability in 40 degree of knee flexion and this stability reduced when knee reached to full extension. At this point, patella moved laterally and the most instability was seen during 20 to 0 degree of knee extension.

  6. Correlation between hip function and knee kinematics evaluated by three-dimensional motion analysis during lateral and medial side-hopping

    Science.gov (United States)

    Itoh, Hiromitsu; Takiguchi, Kohei; Shibata, Yohei; Okubo, Satoshi; Yoshiya, Shinichi; Kuroda, Ryosuke

    2016-01-01

    [Purpose] Kinematic and kinetic characteristics of the limb during side-hopping and hip/knee interaction during this motion have not been clarified. The purposes of this study were to examine the biomechanical parameters of the knee during side hop and analyze its relationship with clinical measurements of hip function. [Subjects and Methods] Eleven male college rugby players were included. A three-dimensional motion analysis system was used to assess motion characteristics of the knee during side hop. In addition, hip range of motion and muscle strength were evaluated. Subsequently, the relationship between knee motion and the clinical parameters of the hip was analyzed. [Results] In the lateral touchdown phase, the knee was positioned in an abducted and externally rotated position, and increasing abduction moment was applied to the knee. An analysis of the interaction between knee motion and hip function showed that range of motion for hip internal rotation was significantly correlated with external rotation angle and external rotation/abduction moments of the knee during the lateral touchdown phase. [Conclusion] Range of motion for hip internal rotation should be taken into consideration for identifying the biomechanical characteristics in the side hop test results.

  7. Spontaneous Knee Ankylosis through Heterotopic Ossification after Total Knee Arthroplasty

    OpenAIRE

    Samuel Boulezaz; Emmanuel Gibon; Philippe Loriaut; Laurent Casabianca; Romain Rousseau; Benjamin Dallaudiere; Hugues Pascal-Moussellard

    2016-01-01

    This paper reports on a case of total ankylosis of the knee after a cruciate-sacrificing cemented total knee arthroplasty (TKA). An 82-year-old female patient previously underwent primary TKA for osteoarthritis twenty years ago in our institution. She had recovered uneventfully and returned to her regular activities. There was no history of postsurgical trauma; however, she progressively lost knee range of motion. Radiographs revealed severe bridging heterotopic ossification.

  8. Dynamic splinting for knee flexion contracture following total knee arthroplasty: a case report.

    Science.gov (United States)

    Finger, Eric; Willis, F Buck

    2008-01-01

    Total Knee Arthroplasty operations are increasing in frequency, and knee flexion contracture is a common pathology, both pre-existing and post-operative. A 61-year-old male presented with knee flexion contracture following a total knee arthroplasty. Physical therapy alone did not fully reduce the contracture and dynamic splinting was then prescribed for daily low-load, prolonged-duration stretch. After 28 physical therapy sessions, the active range of motion improved from -20 degrees to -12 degrees (stiff knee still lacking full extension), and after eight additional weeks with nightly wear of dynamic splint, the patient regained full knee extension, (active extension improved from -12 degrees to 0 degrees ).

  9. Importance of Attenuating Quadriceps Activation Deficits after Total Knee Arthroplasty

    OpenAIRE

    Thomas, Abbey C.; Jennifer E Stevens-Lapsley

    2012-01-01

    Total knee arthroplasty (TKA) is associated with persistent quadriceps dysfunction. Since quadriceps dysfunction impairs functional performance, minimizing quadriceps dysfunction by attenuating central activation deficits early after surgery may improve function later in life. Rehabilitation strategies incorporating neuromuscular electrical stimulation and early, aggressive quadriceps strengthening may prove beneficial. Further, surgical approaches such as minimally invasive TKA may minimize ...

  10. Validity and reliability of using photography for measuring knee range of motion: a methodological study

    Directory of Open Access Journals (Sweden)

    Adie Sam

    2011-04-01

    Full Text Available Abstract Background The clinimetric properties of knee goniometry are essential to appreciate in light of its extensive use in the orthopaedic and rehabilitative communities. Intra-observer reliability is thought to be satisfactory, but the validity and inter-rater reliability of knee goniometry often demonstrate unacceptable levels of variation. This study tests the validity and reliability of measuring knee range of motion using goniometry and photographic records. Methods Design: Methodology study assessing the validity and reliability of one method ('Marker Method' which uses a skin marker over the greater trochanter and another method ('Line of Femur Method' which requires estimation of the line of femur. Setting: Radiology and orthopaedic departments of two teaching hospitals. Participants: 31 volunteers (13 arthritic and 18 healthy subjects. Knee range of motion was measured radiographically and photographically using a goniometer. Three assessors were assessed for reliability and validity. Main outcomes: Agreement between methods and within raters was assessed using concordance correlation coefficient (CCCs. Agreement between raters was assessed using intra-class correlation coefficients (ICCs. 95% limits of agreement for the mean difference for all paired comparisons were computed. Results Validity (referenced to radiographs: Each method for all 3 raters yielded very high CCCs for flexion (0.975 to 0.988, and moderate to substantial CCCs for extension angles (0.478 to 0.678. The mean differences and 95% limits of agreement were narrower for flexion than they were for extension. Intra-rater reliability: For flexion and extension, very high CCCs were attained for all 3 raters for both methods with slightly greater CCCs seen for flexion (CCCs varied from 0.981 to 0.998. Inter-rater reliability: For both methods, very high ICCs (min to max: 0.891 to 0.995 were obtained for flexion and extension. Slightly higher coefficients were obtained

  11. Accuracy of a custom physical activity and knee angle measurement sensor system for patients with neuromuscular disorders and gait abnormalities.

    Science.gov (United States)

    Feldhege, Frank; Mau-Moeller, Anett; Lindner, Tobias; Hein, Albert; Markschies, Andreas; Zettl, Uwe Klaus; Bader, Rainer

    2015-05-06

    Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting.

  12. Accuracy of a Custom Physical Activity and Knee Angle Measurement Sensor System for Patients with Neuromuscular Disorders and Gait Abnormalities

    Directory of Open Access Journals (Sweden)

    Frank Feldhege

    2015-05-01

    Full Text Available Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting.

  13. A pneumatically powered knee-ankle-foot orthosis (KAFO with myoelectric activation and inhibition

    Directory of Open Access Journals (Sweden)

    Ferris Daniel P

    2009-06-01

    Full Text Available Abstract Background The goal of this study was to test the mechanical performance of a prototype knee-ankle-foot orthosis (KAFO powered by artificial pneumatic muscles during human walking. We had previously built a powered ankle-foot orthosis (AFO and used it effectively in studies on human motor adaptation, locomotion energetics, and gait rehabilitation. Extending the previous AFO to a KAFO presented additional challenges related to the force-length properties of the artificial pneumatic muscles and the presence of multiple antagonistic artificial pneumatic muscle pairs. Methods Three healthy males were fitted with custom KAFOs equipped with artificial pneumatic muscles to power ankle plantar flexion/dorsiflexion and knee extension/flexion. Subjects walked over ground at 1.25 m/s under four conditions without extensive practice: 1 without wearing the orthosis, 2 wearing the orthosis with artificial muscles turned off, 3 wearing the orthosis activated under direct proportional myoelectric control, and 4 wearing the orthosis activated under proportional myoelectric control with flexor inhibition produced by leg extensor muscle activation. We collected joint kinematics, ground reaction forces, electromyography, and orthosis kinetics. Results The KAFO produced ~22%–33% of the peak knee flexor moment, ~15%–33% of the peak extensor moment, ~42%–46% of the peak plantar flexor moment, and ~83%–129% of the peak dorsiflexor moment during normal walking. With flexor inhibition produced by leg extensor muscle activation, ankle (Pearson r-value = 0.74 ± 0.04 and knee ( r = 0.95 ± 0.04 joint kinematic profiles were more similar to the without orthosis condition compared to when there was no flexor inhibition (r = 0.49 ± 0.13 for ankle, p = 0.05, and r = 0.90 ± 0.03 for knee, p = 0.17. Conclusion The proportional myoelectric control with flexor inhibition allowed for a more normal gait than direct proportional myoelectric control. The current

  14. 78 FR 38098 - Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity...

    Science.gov (United States)

    2013-06-25

    ... AFFAIRS Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity... Disability Benefits Questionnaire)'' in any correspondence. During the comment period, comments may be viewed.... SUPPLEMENTARY INFORMATION: Title: Knee and Lower Leg Conditions Disability Benefits Questionnaire, VA Form...

  15. Uncertainty of knee joint muscle activity during knee joint torque exertion: the significance of controlling adjacent joint torque.

    Science.gov (United States)

    Nozaki, Daichi; Nakazawa, Kimitaka; Akai, Masami

    2005-09-01

    In the single-joint torque exertion task, which has been widely used to control muscle activity, only the relevant joint torque is specified. However, the neglect of the neighboring joint could make the procedure unreliable, considering our previous result that even monoarticular muscle activity level is indefinite without specifying the adjacent joint torque. Here we examined the amount of hip joint torque generated with knee joint torque and its influence on the activity of the knee joint muscles. Twelve healthy subjects were requested to exert various levels of isometric knee joint torque. The knee and hip joint torques were obtained by using a custom-made device. Because no information about hip joint torque was provided to the subjects, the hip joint torque measured here was a secondary one associated with the task. The amount of hip joint torque varied among subjects, indicating that they adopted various strategies to achieve the task. In some subjects, there was a considerable internal variability in the hip joint torque. Such variability was not negligible, because the knee joint muscle activity level with respect to the knee joint torque, as quantified by surface electromyography (EMG), changed significantly when the subjects were requested to change the strategy. This change occurred in a very systematic manner: in the case of the knee extension, as the hip flexion torque was larger, the activity of mono- and biarticular knee extensors decreased and increased, respectively. These results indicate that the conventional single knee joint torque exertion has the drawback that the intersubject and/or intertrial variability is inevitable in the relative contribution among mono- and biarticular muscles because of the uncertainty of the hip joint torque. We discuss that the viewpoint that both joint torques need to be considered will bring insights into various controversial problems such as the shape of the EMG-force relationship, neural factors that help

  16. The efficacy of brotzman physiotherapy protocol on pain and knee range of motion in post surgical total knee arthroplasty subjects with obesity

    Directory of Open Access Journals (Sweden)

    K Narasimha sridhar

    2013-04-01

    Full Text Available Background:To evaluate the efficacy of Brotzman physiotherapy protocol on pain and knee range of motion in post surgical T.K.A subjects with obesity and normal BMI . Materials and Methods:30 subjects were divided into two groups based on BMI. The group I having normal BMI (18.5 – 24.9 and group II having BMI more than 30. Both groups received Brotzman physiotherapy protocols for duration of 30 - 45 minutes, 1 se ssion per day, 6 days per week for a total of 6 weeks. Results:After 6 weeks treatment period, the subjects in thegroup I were compared with the subjects in the group II. Group I had shown a significant difference with outcome measures at 0.05 level.Conclusion:The study shows that there is a marginal significance ofBROTZMAN physiotherapy protocol in TKA subjects with obesity regarding relief of pain, improvement of knee ROM and WOMAC indx.

  17. Dynamic splinting for knee flexion contracture following total knee arthroplasty: a case report

    OpenAIRE

    Finger, Eric; Willis, F Buck

    2008-01-01

    Total Knee Arthroplasty operations are increasing in frequency, and knee flexion contracture is a common pathology, both pre-existing and post-operative. A 61-year-old male presented with knee flexion contracture following a total knee arthroplasty. Physical therapy alone did not fully reduce the contracture and dynamic splinting was then prescribed for daily low-load, prolonged-duration stretch. After 28 physical therapy sessions, the active range of motion improved from -20° to -12° (stiff ...

  18. Reflex responses to combined hip and knee motion in human chronic spinal cord injury

    OpenAIRE

    Ming Wu, PhD; Brian D. Schmit, PhD

    2010-01-01

    The relative contributions of hip and knee proprioceptors to the origination of extensor spasms were examined in 11 subjects with chronic spinal cord injury (SCI). Ramp and hold extension and combined hip and knee oscillation movements were imposed to the right leg while the ankle was held in a static position by a custom-designed robot. Isometric joint torques of the hip, knee, and ankle and surface electromyograms (EMGs) from seven leg muscles were recorded following controlled hip and knee...

  19. Testosterone Reduces Knee Passive Range of Motion and Expression of Relaxin Receptor Isoforms via 5α-Dihydrotestosterone and Androgen Receptor Binding

    OpenAIRE

    Firouzeh Dehghan; Sekaran Muniandy; Ashril Yusof; Naguib Salleh

    2014-01-01

    Ovarian steroids such as estrogen and progesterone have been reported to influence knee laxity. The effect of testosterone, however, remains unknown. This study investigated the effect of testosterone on the knee range of motion (ROM) and the molecular mechanisms that might involve changes in the expression of relaxin receptor isoforms, Rxfp1 and Rxfp2 in the patella tendon and lateral collateral ligament of the female rat knee. Ovariectomized adult female Wistar rats received three days trea...

  20. Comparison of self-reported and measured range of motion in total knee arthroplasty patients.

    Science.gov (United States)

    Unver, Bayram; Nalbant, Abdurrahman; Karatosun, Vasfi

    2015-08-01

    Total knee arthroplasty (TKA) is an established method used in the treatment of end-stage knee osteoarthritis. Range of motion (ROM) and relief from pain show success of TKA. One of the most important aims of this treatment is to achieve an adequate ROM. Numerous outcome instruments and patient-reported questionnaires are in use to evaluate of TKA patients. For this purpose, disease-specific questionnaires and self-reported ROM and function evaluation tools are also being developed. The most important criteria in musculoskeletal care is assessing the joint mobility of the patient's. Joint mobility can be measured with visual estimates, universal goniometer, X-ray radiography, digital gravity goniometers and applications found in smart phones. Apart from the reliability and validity of the method, obtaining the same results from different examiners is very important. The clinical follow-up of patients is an important part of postoperative care after TKA. The follow-up interval and duration remain dependent on the physician's anticipation of the clinical progress of the individual patient. Long-term surveillance of joint arthroplasty is necessary, but it has also become increasingly burdensome as greater numbers of TKAs are performed, and in younger populations. Patient self-reported questionnaires and self-goniometric measurement are used by many investigators to decrease this burden on the surgeon or staff, and in combination with telemedicine radiographs might be a reasonable option to routine clinic visits. They could reasonably be expected to lower the burden on both the patient and the clinician without eliminating contact and thus sacrificing quality of care. At the same time, it would reduce the financial burden too. Self-reported measured ROM can use in the routine follow-ups to reduce surgeons, physiotherapist and other staff. PMID:26417576

  1. Autologous platelet gel and fibrin sealant enhance the efficacy of total knee arthroplasty : improved range of motion, decreased length of stay and a reduced incidence of arthrofibrosis

    NARCIS (Netherlands)

    Everts, Peter A. M.; Devilee, Roger J. J.; Oosterbos, Cornelis J. M.; Mahoney, Christine Brown; Schattenkerk, Maarten Eeftinck; Knape, Johannes T. A.; van Zundert, Andre

    2007-01-01

    In this study we describe the potential role of autologous platelet gel and fibrin sealant in unilateral total knee arthroplasty to improve the postoperative range of motion and to reduce the incidence of arthrofibrosis. Total knee arthroplasty is often associated with a considerable amount of post-

  2. The influence of kinesiotherapy on joint motion and process of strengthening selected muscules of leg after the episode of knee joint sprain

    Directory of Open Access Journals (Sweden)

    Jacek Wilczyński

    2013-12-01

    Full Text Available Introduction: Traumatic damage to the knee joint by twisting is a common health problem in people of all ages. Aim of the research: To compare the results of 3-week complex physiotherapy (kinesiotherapy and physiotherapy with partial physiotherapy (physical therapy in the process of rehabilitation of the knee joint after twisting. Material and methods: A factor differentiating groups was medical gymnastics – kinesiotherapy. Fifty patients of the Rehabilitation Unit of the District Hospital in Staszów divided into two numerically equal groups of subjects (25 people each were assessed twice (before and after improving physiotherapy for muscle strength and range of movement of the knee joint. Each participant of the rehabilitation had the healthy lower limb compared to the injured one treated with physiotherapy activities in terms of the above-mentioned indicators. The age of patients with damage to the knee joint was between 20 and 64 years old. The median age was 42 years. The patients were from urban and rural areas of the Staszów town region. They represented various professions. Results : The applied physiotherapy improved muscle strength (measured in Lovett scale points and increased the range of movements (defined in degrees with a goniometer of the injured knee. While assessing the effects of the therapy, there was no significant difference between the groups of studied subjects who underwent complex and partial rehabilitation. Conclusions: The obtained results of rehabilitation showed that the model of physiotherapy enhanced with physical exercise allows for faster muscle growth and increases the amplitude of the range of motion in the injured joint.

  3. Use of a portable motion analysis system for knee dynamic stability assessment in anterior cruciate ligament deficiency during single-legged hop landing

    Directory of Open Access Journals (Sweden)

    Man-Yi Yeung

    2016-07-01

    Conclusion: The altered knee kinematics in ACL-deficient patients can be revealed by a portable motion capture system, which may enable the clinical application of kinematic assessment in the evaluation of ACL deficiency.

  4. ARTHROFIBROSIS FOLLOWING TOTAL KNEE ARTHROPLASTY

    Directory of Open Access Journals (Sweden)

    Ravi B. Solanki

    2014-11-01

    Full Text Available Arthrofibrosis following total knee arthroplasty is an uncommon complication defined as less than 80 degrees of knee flexion 6-8 weeks post operatively. It is characterized by abnormal scarring of the joint in which the formation of dense fibrous tissue and tissue metaplasia prevent normal range of motion. Clinical features include limited knee Range of motion with extension deficit, pain with activities of daily living and unusual amount of pain and swelling post operatively in the absence of infection, bleeding or mechanical complications. We present case of 55 years old female who undergone for total knee replacement before 3 months and presented to our department with complain of knee pain and swelling with activities of daily living. She was diagnosed on the basis of clinical examination. Her detailed evaluation was carried out and Physiotherapy treatment was started.

  5. Multiple LREK active contours for knee meniscus ultrasound image segmentation.

    Science.gov (United States)

    Faisal, Amir; Ng, Siew-Cheok; Goh, Siew-Li; George, John; Supriyanto, Eko; Lai, Khin W

    2015-10-01

    Quantification of knee meniscus degeneration and displacement in an ultrasound image requires simultaneous segmentation of femoral condyle, meniscus, and tibial plateau in order to determine the area and the position of the meniscus. In this paper, we present an active contour for image segmentation that uses scalable local regional information on expandable kernel (LREK). It includes using a strategy to adapt the size of a local window in order to avoid being confined locally in a homogeneous region during the segmentation process. We also provide a multiple active contours framework called multiple LREK (MLREK) to deal with multiple object segmentation without merging and overlapping between the neighboring contours in the shared boundaries of separate regions. We compare its performance to other existing active contour models and show an improvement offered by our model. We then investigate the choice of various parameters in the proposed framework in response to the segmentation outcome. Dice coefficient and Hausdorff distance measures over a set of real knee meniscus ultrasound images indicate a potential application of MLREK for assessment of knee meniscus degeneration and displacement. PMID:25910057

  6. Influence of advanced prosthetic knee joints on perceived performance and everyday life activity level of low-functional persons with a transfemoral amputation or knee disarticulation

    NARCIS (Netherlands)

    Theeven, P.J.; Hemmen, B.; Geers, R.P.; Smeets, R.J.P.; Brink, P.R.; Seelen, H.A.

    2012-01-01

    OBJECTIVE: To assess the effects of two types of microprocessor-controlled prosthetic knee joints (MPKs) on perceived performance and everyday life activity level. DESIGN: Randomized cross-over trial. SUBJECTS: Thirty persons with a unilateral above-knee amputation or knee disarticulation classified

  7. Provocative mechanical tests of the peripheral nervous system affect the joint torque-angle during passive knee motion.

    Science.gov (United States)

    Andrade, R J; Freitas, S R; Vaz, J R; Bruno, P M; Pezarat-Correia, P

    2015-06-01

    This study aimed to determine the influence of the head, upper trunk, and foot position on the passive knee extension (PKE) torque-angle response. PKE tests were performed in 10 healthy subjects using an isokinetic dynamometer at 2°/s. Subjects lay in the supine position with their hips flexed to 90°. The knee angle, passive torque, surface electromyography (EMG) of the semitendinosus and quadriceps vastus medialis, and stretch discomfort were recorded in six body positions during PKE. The different maximal active positions of the cervical spine (neutral; flexion; extension), thoracic spine (neutral; flexion), and ankle (neutral; dorsiflexion) were passively combined for the tests. Visual analog scale scores and EMG were unaffected by body segment positioning. An effect of the ankle joint was verified on the peak torque and knee maximum angle when the ankle was in the dorsiflexion position (P knee submaximal torque (P knee passive submaximal torque when the cervical and thoracic spines were flexed (P segments influence torque-angle response since different positions of head, upper trunk, and foot induce dissimilar knee mechanical responses during passive extension.

  8. Knee pain during activities of daily living and its relationship with physical activity in patients with early and severe knee osteoarthritis.

    Science.gov (United States)

    Fukutani, Naoto; Iijima, Hirotaka; Aoyama, Tomoki; Yamamoto, Yuko; Hiraoka, Masakazu; Miyanobu, Kazuyuki; Jinnouchi, Masashi; Kaneda, Eishi; Tsuboyama, Tadao; Matsuda, Shuichi

    2016-09-01

    This study aimed to investigate whether knee pain during various activities of daily living (ADLs) is associated with physical activity in patients with early and severe knee osteoarthritis (OA). We hypothesized that the painful ADLs associated with decreased physical activity differ according to disease severity. This cross-sectional study enrolled 270 patients with medial knee OA, assigned to either the early (Kellgren Lawrence [K/L] grade 1-2) or the severe group (K/L grade 3-4). Physical activity was assessed using a pedometer. Knee pain during six ADLs (waking up in the morning, walking on a flat surface, ascending stairs, etc.) was evaluated using a questionnaire. We performed multiple regression and quantile regression analysis to investigate whether knee pain during each ADL was associated with physical activity. In the early group, the more knee pain they experienced while ascending stairs, the lower their physical activity was (75th regression coefficient = -1033.70, P = 0.018). In the severe group, the more knee pain they experienced while walking on a flat surface or bending to the floor or standing up, the lower their physical activity was (unstandardized coefficients = -1850.87, P = 0.026; unstandardized coefficients = -2640.35, P = 0.010). Knee pain while ascending stairs and while walking on a flat surface or bending to the floor or standing up was a probable limiting factor for physical activity in early and severe knee OA, respectively. These findings suggested that a reduction in task-specific knee pain according to disease severity could improve physical activity levels.

  9. Interaction between pre-landing activities and stiffness regulation of the knee joint musculoskeletal system in the drop jump: implications to performance.

    Science.gov (United States)

    Horita, T; Komi, P V; Nicol, C; Kyröläinen, H

    2002-11-01

    The purpose of the present study was to investigate the interaction between the pre-landing activities and the stiffness regulation of the knee joint musculoskeletal system and the takeoff speed during a drop jump (DJ). Nine healthy male subjects performed a DJ test from the height of 50 cm. The surface electromyographic (EMG) activity of the vastus lateralis (VL) muscle was recorded to evaluate both the pre-landing and post-landing muscle activation levels. Simultaneous recording of the jumping motion and ground reaction force was performed by a high-speed video camera (100 frames x s(-1)), and a force platform was employed to allow joint moment analysis. Joint stiffness was calculated by a linear regression of the knee joint moment/angle relationship. Elasticity of the knee extensor muscle during DJ was estimated by means of a four-element muscle model consisting of a parallel elastic component, a series elastic component (SEC), a viscous damper, and a contractile element. DJ performance correlated positively with the positive peak power of the knee joint (P knee joint at the end of stretch (P power of the ankle joint. The knee joint moment at the end of stretch correlated with the SEC stiffness during the transmission phase from the end of the initial impact to the onset of the concentric action (P knee extensors (P analysis showed that the SEC stiffness during the transmission phase of the knee joint can be explained by a combination of the pre-activity of the VL muscle and the knee joint angular velocity at touchdown (F = 5.76, P knee extensor muscle in conjunction with the muscle contractile property play a major role in regulating the performance in DJ.

  10. Effect of Planning on Trunk Motion and Knee Moments During a Side Step Cut Task

    Science.gov (United States)

    Houck, Jeff; Gorniak, Stacey; Nicholson, Kristen

    2004-03-01

    Recent studies suggest that alterations in knee biomechanics associated with unanticipated cutting tasks place athletes at higher risk of knee injuries. Besier et al observed alterations in knee moments during unanticipated cutting tasks that were consistent with in-vitro ACL injury mechanisms. During similar tasks, Patla et al observed lateral trunk lean and decreased foot placement, suggesting that full body center of mass control is perturbed during such tasks. The purpose of this study was to compare the trunk and knee frontal plane moments and evaluate a relationship between the two during unanticipated cutting tasks. The results of this study suggest that there is a relationship between the trunk and knee frontal plane moments during the first 200-400ms of the stance phase of gait.

  11. Evaluation Of Range Of Motion After Arthroscopic Arthroloysis In Postoperative Arthrofibrosis Of The Knee

    Directory of Open Access Journals (Sweden)

    Moghtader Azadi G

    2003-07-01

    Full Text Available Arthrofibrosis continue to be a difficult complication of operative procedures of trauma about the knee. We present our experience in 8 cases of arthroscopic Arthrolysis between 1997 and 2001. in 3 Cases the etiology was prior Knee ligament surgery and 5 cases had sustained fractures about the knee. Technique begins with the liberation of the adhesions of suprapatellar Pouch, continues down both gutters , and ends with a cleaning of the notch where necessary. The result obtained are very satisfactory, with an average increase in the arc of mobility of 61 degrees."n 

  12. A prosthetic knee using magnetorhelogical fluid damper for above-knee amputees

    Science.gov (United States)

    Park, Jinhyuk; Choi, Seung-Bok

    2015-04-01

    A prosthetic knee for above-knee (AK) amputees is categorized into two types; namely a passive and an active type. The passive prosthetic knee is generally made by elastic materials such as carbon fiber reinforced composite material, titanium and etc. The passive prosthetic knee easy to walk. But, it has disadvantages such that a knee joint motion is not similar to ordinary people. On the other hand, the active prosthetic knee can control the knee joint angle effectively because of mechanical actuator and microprocessor. The actuator should generate large damping force to support the weight of human body. But, generating the large torque using small actuator is difficult. To solve this problem, a semi-active type prosthetic knee has been researched. This paper proposes a semi-active prosthetic knee using a flow mode magneto-rheological (MR) damper for AK amputees. The proposed semi-active type prosthetic knee consists of the flow mode MR damper, hinge and prosthetic knee body. In order to support weight of human body, the required energy of MR damper is smaller than actuator of active prosthetic leg. And it can control the knee joint angle by inducing the magnetic field during the stance phase.

  13. A new protocol from real joint motion data for wear simulation in total knee arthroplasty: stair climbing.

    Science.gov (United States)

    Battaglia, Santina; Belvedere, Claudio; Jaber, Sami Abdel; Affatato, Saverio; D'Angeli, Valentina; Leardini, Alberto

    2014-12-01

    In its normal lifespan, a knee prosthesis must bear highly demanding loading conditions, going beyond the sole activity of level walking required by ISO standard 14243. We have developed a protocol for in vitro wear simulation of stair climbing on a displacement controlled knee simulator. The flexion/extension angle, intra/extra rotation angle, and antero/posterior translation were obtained in patients by three-dimensional video-fluoroscopy. Axial load data were collected by gait analysis. Kinematics and load data revealed a good consistence across patients, in spite of the different prosthesis size. The protocol was then implemented and tested on a displacement controlled knee wear simulator, showing an accurate reproduction of stair climbing waveforms with a relative error lower than 5%.

  14. Self-reported activity level and knee function in amateur football players: the influence of age, gender, history of knee injury and level of competition.

    OpenAIRE

    Frobell, Richard; Svensson, E.; Göthrick, M; Roos, Ewa

    2008-01-01

    The aim of this study is to investigate if self-reported activity level or knee functions are influenced by subject characteristics, level of competition and history of knee injury. Cross-Sectional study using questionnaires distributed at a personal visit. One hundred and eighty-eight (65 women) amateur football players in 10 football clubs from each division below national level participated in the study. Self-reported Tegner Activity Scale, and the Knee injury and Osteoarthritis Outcome Sc...

  15. Effect of Continuous Passive Motion on Pain and Range of Motion after Knee Arthroplasty%持续被动运动在膝关节置换术后早期康复治疗中的作用

    Institute of Scientific and Technical Information of China (English)

    王东; 魏更生; 宋华伟; 蒋毅; 王艺伟; 吴磊

    2011-01-01

    Objective To evaluate the effect of continuous passive motion (CPM) as an adjunct to active physiotherapy on pain and range of motion (ROM) after knee arthroplasty. Methods 20 female osteoarthritis patients (40 knees) undergoing bilateral knee arthroplasty were assigned into two groups. The experimental group received CPM and active physiotherapy twice a day while the control group received active physiotherapy only. They were assessed with visual analogue scale (VAS) and goniometer on pain and ROM of knee before and after operation. Results There were no statistical difference between these two groups for any outcome measures either 2 weeks or 3 months after operation (P>0.05), and they all improved in pain and ROM 3 months after operation compared with before (P< 0.01). Conclusion CPM as an adjunctive therapy is not found to have an additional effect on pain or ROM 3 months after operation while active physiotherapy was used.%目的 评价持续被动运动(CPM)在膝关节置换术后早期康复治疗中对疼痛和膝关节主动屈伸活动度的作用.方法 20例(40膝)女性重度骨性关节炎患者行双膝关节同时置换术.分为实验组和对照组,每组10例20膝.实验组术后每天2次行CPM和主动康复治疗,对照组每天2次主动康复治疗.术前、术后2周和3个月应用疼痛视觉模拟评分(VAS)和角度测量仪评估两组患者的疼痛和膝关节主动屈伸活动度.结果 术后2周和3个月,两组患者的疼痛评分和膝关节活动度均无显著性差异(P>0.05).与术前相比,疼痛评分和膝关节主动屈伸活动度在术后3个月均有明显改善(P<0.01).结论 进行主动康复治疗后,CPM的辅助应用对膝关节置换术后3个月内疼痛和关节活动度的改善无明显促进作用.

  16. Effects of ankle joint mobilization with movement and weight-bearing exercise on knee strength, ankle range of motion, and gait velocity in patients with stroke: a pilot study.

    Science.gov (United States)

    An, Chang-Man; Won, Jong-Im

    2016-01-01

    [Purpose] The purpose of this study was to investigate the effects of ankle joint mobilization with movement on knee strength, ankle range of motion, and gait velocity, compared with weight-bearing exercise in stroke patients. [Subjects and Methods] Thirty subjects with chronic stroke were divided into three groups: MWM (n = 12), WBE (n = 8), and control (n = 10). All groups attended physical therapy sessions 3 times a week for 5 weeks. Subjects in the MWM group performed mobilization with movement exercises, whilst participants in the WBE group performed weight-bearing exercises. Knee peak torque, ankle range of motion, and spatiotemporal gait parameters were evaluated before and after the interventions. [Results] Knee extensor peak torque increased significantly in both MWM and WBE groups. However, only the MWM group showed significant improvement in passive and active ankle range of motion and gait velocity, among the three groups. [Conclusion] Ankle joint mobilization with movement intervention is more effective than simple weight-bearing intervention in improving gait speed in stroke patients with limited ankle motion.

  17. Effects of Low-Impact Dance on Blood Biochemistry, Bone Mineral Density, the Joint Range of Motion of Lower Extremities, Knee Extension Torque, and Fall in Females.

    Science.gov (United States)

    Wu, Hui Ying; Tu, Jui Hung; Hsu, Chin Hsing; Tsao, Te Hung

    2016-01-01

    The effect of low-impact dance on blood metabolites, the joint range of motion (ROM) of the lower extremities, knee extension torque, bone mass density (BMD), the number of falls, and the confidence to perform daily activities (Modified Falls Efficacy Scale [MFES]) was examined in older sedentary women (age: 59 ± 4 years) before and after a 16-week intervention. Results showed that the average score for the MFES, some parameters of blood chemistry, and joint ROM were significantly improved after low-impact intervention. In addition to improvements in blood lipids and body fat percentages, the increases shown in the parameters regarding the lower extremities may contribute to confidence in performing common daily activities in older women, although the number of falls did not significantly differ between the two groups during the 16-week period. PMID:25642949

  18. Effects of Low-Impact Dance on Blood Biochemistry, Bone Mineral Density, the Joint Range of Motion of Lower Extremities, Knee Extension Torque, and Fall in Females.

    Science.gov (United States)

    Wu, Hui Ying; Tu, Jui Hung; Hsu, Chin Hsing; Tsao, Te Hung

    2016-01-01

    The effect of low-impact dance on blood metabolites, the joint range of motion (ROM) of the lower extremities, knee extension torque, bone mass density (BMD), the number of falls, and the confidence to perform daily activities (Modified Falls Efficacy Scale [MFES]) was examined in older sedentary women (age: 59 ± 4 years) before and after a 16-week intervention. Results showed that the average score for the MFES, some parameters of blood chemistry, and joint ROM were significantly improved after low-impact intervention. In addition to improvements in blood lipids and body fat percentages, the increases shown in the parameters regarding the lower extremities may contribute to confidence in performing common daily activities in older women, although the number of falls did not significantly differ between the two groups during the 16-week period.

  19. Measurement of the screw-home motion of the knee is sensitive to errors in axis alignment.

    Science.gov (United States)

    Piazza, S J; Cavanagh, P R

    2000-08-01

    Measurements of joint angles during motion analysis are subject to error caused by kinematic crosstalk, that is, one joint rotation (e. g., flexion) being interpreted as another (e.g., abduction). Kinematic crosstalk results from the chosen joint coordinate system being misaligned with the axes about which rotations are assumed to occur. The aim of this paper is to demonstrate that measurement of the so-called "screw-home" motion of the human knee, in which axial rotation and extension are coupled, is especially prone to errors due to crosstalk. The motions of two different two-segment mechanical linkages were examined to study the effects of crosstalk. The segments of the first linkage (NSH) were connected by a revolute joint, but the second linkage (SH) incorporated gearing that caused 15 degrees of screw-home rotation to occur with 90 degrees knee flexion. It was found that rotating the flexion axis (inducing crosstalk) could make linkage NSH appear to exhibit a screw-home motion and that a different rotation of the flexion axis could make linkage SH apparently exhibit pure flexion. These findings suggest that the measurement of screw-home rotation may be strongly influenced by errors in the location of the flexion axis. The magnitudes of these displacements of the flexion axis were consistent with the inter-observer variability seen when five experienced observers defined the flexion axis by palpating the medial and lateral femoral epicondyles. Care should be taken when interpreting small internal-external rotations and abduction-adduction angles to ensure that they are not the products of kinematic crosstalk.

  20. Anterior cruciate ligament injury after more than 20 years: I. Physical activity level and knee function.

    Science.gov (United States)

    Tengman, E; Brax Olofsson, L; Nilsson, K G; Tegner, Y; Lundgren, L; Häger, C K

    2014-12-01

    Little is known about physical activity level and knee function including jump capacity and fear of movement/reinjury more than 20 years after injury of the anterior cruciate ligament (ACL). Seventy persons with unilateral ACL injury participated (23 ± 2 years post-injury): 33 treated with physiotherapy in combination with surgical reconstruction (ACLR ), and 37 treated with physiotherapy alone (ACLPT ). These were compared with 33 age- and gender-matched controls. Assessment included knee-specific and general physical activity level [Tegner activity scale, International Physical Activity Questionnaire (IPAQ)], knee function [Lysholm score, Knee injury and Osteoarthritis Outcome Score (KOOS)], jump capacity (one-leg hop, vertical jump, side hops), and fear of movement/reinjury [Tampa Scale for Kinesiophobia (TSK)]. Outcomes were related to degree of osteoarthritis (OA). ACL-injured had lower Lysholm, KOOS, and Tegner scores than controls (P knee-related effects of ACL injury more than 20 years later.

  1. Comparing the Effects of Therapeutic Exercise and Hydrotherapy on Pain Severity and Knee Range of Motion in Patients with Hemophilia: A Randomized Controlled Trial

    Directory of Open Access Journals (Sweden)

    V Mazloum

    2013-10-01

    . Results: Both experimental groups exhibited significant reduction of pain along with improved knee flexion and extension compared with the control group (P<0.001. Pain reduction in subjects treated in water treatment was significantly higher than exercise group in drought (P0.05. Conclusion: The use of therapeutic exercise in water with regular exercise rehabilitation for patients with hemophilia can be helpful to reduce pain and improve range of motion in hemophilia patients. The effect of exercise therapy on pain reduction is more effective compared to traditional pain therapy. Key words: Hydrotherapy, Exercise Therapy, Hemophilia, Knee Range of Motion

  2. Neuromuscular activity and knee kinematics in adolescents with patellofemoral pain

    DEFF Research Database (Denmark)

    Rathleff, Michael Skovdal; Samani, Afshin; Olesen, Jens L.;

    2013-01-01

    This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS).......This study aimed to investigate the neuromuscular control of the knee during stair descent among female adolescents with patellofemoral pain (PFP) and to report its association with self-reported clinical status assessed by the Knee Injury and Osteoarthritis Outcome Score (KOOS)....

  3. The remains of anterior cruciate ligament graft tension after cyclic knee motion

    NARCIS (Netherlands)

    Arnold, MR; Lie, DTT; Verdonschot, N; de Graaf, R; Amis, AA; van Kampen, A

    2005-01-01

    Background: There is sometimes a return of excess knee laxity after anterior cruciate ligament reconstruction. One of the contributing factors might be a loss in graft tension. It is unknown whether the tension imposed on an anterior cruciate ligament graft degrades with time and, if so, the effect

  4. Influence of restricted vision and knee joint range of motion on gait properties during level walking and stair ascent and descent.

    Science.gov (United States)

    Demura, Tomohiro; Demura, Shin-ich

    2011-01-01

    Because elderly individuals experience marked declines in various physical functions (e.g., vision, joint function) simultaneously, it is difficult to clarify the individual effects of these functional declines on walking. However, by imposing vision and joint function restrictions on young men, the effects of these functional declines on walking can be clarified. The authors aimed to determine the effect of restricted vision and range of motion (ROM) of the knee joint on gait properties while walking and ascending or descending stairs. Fifteen healthy young adults performed level walking and stair ascent and descent during control, vision restriction, and knee joint ROM restriction conditions. During level walking, walking speed and step width decreased, and double support time increased significantly with vision and knee joint ROM restrictions. Stance time, step width, and walking angle increased only with knee joint ROM restriction. Stance time, swing time, and double support time were significantly longer in level walking, stair descent, and stair ascent, in that order. The effects of vision and knee joint ROM restrictions were significantly larger than the control conditions. In conclusion, vision and knee joint ROM restrictions affect gait during level walking and stair ascent and descent. This effect is marked in stair ascent with knee joint ROM restriction.

  5. A magnetorheological fluid-based controllable active knee brace

    Science.gov (United States)

    Ahmadkhanlou, Farzad; Zite, Jamaal L.; Washington, Gregory N.

    2007-04-01

    High customization costs and reduction of natural mobility put current rehabilitative knee braces at a disadvantage. A resolution to this problem is to integrate a Magnetorheological (MR) fluid-based joint into the system. A MR joint will allow patients to apply and control a resistive torque to knee flexion and extension. The resistance torque can also be continuously adjusted as a function of extension angle and patient strength (or as a function of time), which is currently impossible with state of the art rehabilitative knee braces. A novel MR fluid-based controllable knee brace is designed and prototyped in this research. The device exhibits large resistive torque in the on-state and low resistance in the offstate. The controllable variable stiffness, compactness, and portability of the system make it a proper alternative to current rehabilitative knee braces.

  6. A magnetorheological fluid based orthopedic active knee brace

    Science.gov (United States)

    Zite, Jamaal L.; Ahmadkhanlou, Farzad; Neelakantan, Vijay A.; Washington, Gregory N.

    2006-03-01

    The disadvantage of current knee braces ranges from high cost for customization to a loss in physical mobility and limited rehabilitative value. One approach to solving this problem is to use a Magnetorheological (MR) device to make the knee brace have a controllable resistance. Our design solution is to replace the manufacturer's joint with an rotary MR fluid based shear damper. The device is designed based on a maximum yield stress, a corresponding magnetic field, a torque and the MR fluid viscosity. The analytical and experimental results show the advantages and the feasibility of using the proposed MR based controllable knee braces.

  7. Prosthesis alignment affects axial rotation motion after total knee replacement: a prospective in vivo study combining computed tomography and fluoroscopic evaluations

    Directory of Open Access Journals (Sweden)

    Harman Melinda K

    2012-10-01

    Full Text Available Abstract Background Clinical consequences of alignment errors in total knee replacement (TKR have led to the rigorous evaluation of surgical alignment techniques. Rotational alignment in the transverse plane has proven particularly problematic, with errors due to component malalignment relative to bone anatomic landmarks and an overall mismatch between the femoral and tibial components’ relative positions. Ranges of nominal rotational alignment are not well defined, especially for the tibial component and for relative rotational mismatch, and some studies advocate the use of mobile-bearing TKR to accommodate the resulting small rotation errors. However, the relationships between prosthesis rotational alignment and mobile-bearing polyethylene insert motion are poorly understood. This prospective, in vivo study evaluates whether component malalignment and mismatch affect axial rotation motions during passive knee flexion after TKR. Methods Eighty patients were implanted with mobile-bearing TKR. Rotational alignment of the femoral and tibial components was measured from postoperative CT scans. All TKR were categorized into nominal or outlier groups based on defined norms for surgical rotational alignment relative to bone anatomic landmarks and relative rotational mismatch between the femoral and tibial components. Axial rotation motion of the femoral, tibial and polyethylene bearing components was measured from fluoroscopic images acquired during passive knee flexion. Results Axial rotation motion was generally accomplished in two phases, dominated by polyethylene bearing rotation on the tibial component in early to mid-flexion and then femoral component rotation on the polyethylene articular surface in later flexion. Opposite rotations of the femur-bearing and bearing-baseplate articulations were evident at flexion greater than 80°. Knees with outlier alignment had lower magnitudes of axial rotation and distinct transitions from external to

  8. Effects of mild and severe knee joint pain on various activities of daily living in the female elderly

    OpenAIRE

    Sugiura, Hiroki; Demura, Shinichi

    2013-01-01

    This study aimed to examine the differences in the ability to perform various activities of daily living (ADLs) among groups with various knee problems. The participants consisted of 328 elderly females (age 60-94; mean age 76.1 years; standard deviation 6.2). The subjects were classified into three groups: those without knee pain, those with mild knee pain, and those with severe knee pain. ADLs with markedly higher (>97%) and lower (

  9. Effects of Mild and Severe Knee Joint Pain on Various Activities of Daily Living in the Female Elderly

    OpenAIRE

    Hiroki Sugiura; Shinichi Demura

    2013-01-01

    This study aimed to examine the differences in the ability to perform various activities of daily living (ADLs) among groups with various knee problems. The participants consisted of 328 elderly females (age 60–94; mean age 76.1 years; standard deviation 6.2). The subjects were classified into three groups: those without knee pain, those with mild knee pain, and those with severe knee pain. ADLs with markedly higher (>97%) and lower (

  10. Geometric control of active collective motion

    CERN Document Server

    Theillard, Maxime; Saintillan, David

    2016-01-01

    Recent experimental studies have shown that confinement can profoundly affect self-organization in semi-dilute active suspensions, leading to striking features such as the formation of steady and spontaneous vortices in circular domains and the emergence of unidirectional pumping motions in periodic racetrack geometries. Motivated by these findings, we analyze the two-dimensional dynamics in confined suspensions of active self-propelled swimmers using a mean-field kinetic theory where conservation equations for the particle configurations are coupled to the forced Navier-Stokes equations for the self-generated fluid flow. In circular domains, a systematic exploration of the parameter space casts light on three distinct states: equilibrium with no flow, stable vortex, and chaotic motion, and the transitions between these are explained and predicted quantitatively using a linearized theory. In periodic racetracks, similar transitions from equilibrium to net pumping to traveling waves to chaos are observed in ag...

  11. Motion

    CERN Document Server

    Graybill, George

    2007-01-01

    Take the mystery out of motion. Our resource gives you everything you need to teach young scientists about motion. Students will learn about linear, accelerating, rotating and oscillating motion, and how these relate to everyday life - and even the solar system. Measuring and graphing motion is easy, and the concepts of speed, velocity and acceleration are clearly explained. Reading passages, comprehension questions, color mini posters and lots of hands-on activities all help teach and reinforce key concepts. Vocabulary and language are simplified in our resource to make them accessible to str

  12. BLADE technology to eliminate MRI of knee joint motion artifacts%BLADE技术在消除MRI膝关节运动伪影方面的应用

    Institute of Scientific and Technical Information of China (English)

    顾勇坚; 郑建刚; 许建兴; 刘良卿; 周鸿雁

    2012-01-01

    目的 探讨刀锋伪影校正(BLADE)技术在消除MRI膝关节运动伪影的应用价值.方法 32例膝关节常规MRI检查中出现运动伪影的患者,改用BLADE技术扫描(PD矢状位、T2矢状位),以是否能够清晰显示膝关节结构、半月板及交叉韧带为标准,与常规序列对比评估BLADE技术对消除膝关节运动伪影的应用价值.结果 膝关节常规序列扫描中出现运动伪影,改用BLADE技术扫描后,图像运动伪影消除,图像质量明显改善.结论 BLADE技术对膝关节常规扫描中产生的运动伪影有明显的校正作用,可广泛用于产生运动伪影的膝关节MRI检查中.%Objective To investigate the value of the blade artifact correction (BLADE) technology in eliminating the knee joint motion artifacts in the MR examination. Methods 32 patients with motion artifacts in the knee conventional MR examination were added standard BLADE technology to scan (PD sagittal, T2 sagittal), compared with conventional sequence, assessed the value of the BLADE technology to eliminate motion artifacts of the knee with a standard of clear display of the structure of the knee, meniscus and cruciate ligament. Results Switching to BLADE technology scanning, the image motion artifacts produced in the knee conventional examination was disappeared, and the image quality was improved significantly. Conclusion BLADE technology with significant role in correction the motion artifacts produced in the conventional scanning of the knee can be widely used to produce motion artifacts knee MRI examination.

  13. Effect of a high intensity quadriceps fatigue protocol on knee joint mechanics and muscle activation during gait in young adults.

    Science.gov (United States)

    Murdock, Gillian Hatfield; Hubley-Kozey, Cheryl L

    2012-02-01

    The purpose of this study was to determine the effect of impaired quadriceps function on knee joint biomechanics and neuromuscular function during gait. Surface electromyograms, three-dimensional motion and ground reaction forces were collected during gait before and after 20 healthy adults completed a high intensity quadriceps fatigue protocol. Pattern recognition techniques were utilized to examine changes in amplitude and temporal characteristics of all gait variables. The fatigue protocol resulted in decreased knee extensor torque generation and quadriceps median power frequencies for 18 of 20 participants (p gait data from these 18 participants was analyzed. The knee external rotation angle increased (p knee motion and loading characteristics were altered following a high intensity fatigue protocol in a manner that may place the knee joint at greater risk for joint pathology and injury.

  14. Displacement of the medial meniscus within the passive motion characteristics of the human knee joint: an RSA study in human cadaver knees.

    NARCIS (Netherlands)

    Tienen, T.G. van; Buma, P.; Scholten, J.G.; Kampen, A. van; Veth, R.P.H.; Verdonschot, N.J.J.

    2005-01-01

    The objective of this study was to validate an in vitro human cadaver knee-joint model for the evaluation of the meniscal movement during knee-joint flexion. The question was whether our model showed comparable meniscal displacements to those found in earlier meniscal movement studies in vivo. Furth

  15. Physiological alterations of maximal voluntary quadriceps activation by changes of knee joint angle.

    Science.gov (United States)

    Becker, R; Awiszus, F

    2001-05-01

    The purpose of this study was to investigate the influence of different angles of the knee joint on voluntary activation of the quadriceps muscle, estimating the ability of a subject to activate a muscle maximally by means of voluntary contraction. Isometric torque measurement was performed on 6 healthy subjects in 5 degrees intervals between 30 degrees and 90 degrees of knee joint flexion. Superimposed twitches at maximal voluntary contraction (MVC) and at a level of 60% and 40% of the MVC were applied and the voluntary activation estimated. At between 30 degrees and 75 degrees of knee flexion, the maximal extension torque increased at an average rate of 2.67 +/- 0.6 Nm/degree, followed by a decline with further flexion. However, throughout the joint-angle range tested, voluntary activation increased on average by 0.37%/degree with a maximum at 90 degrees of flexion. Due to the influence of joint position it is not possible to generalize results obtained at the knee joint angle of 90 degrees of flexion, which is usually used for the quadriceps twitch-interpolation technique. Consequently, it is useful to investigate voluntary activation deficits in knee joint disorders at a range of knee joint angles that includes, in particular, the more extended joint angles used frequently during daily activity.

  16. Effect of generalized joint hypermobility on knee function and muscle activation in children and adults

    DEFF Research Database (Denmark)

    Jensen, Bente Rona; Olesen, Annesofie T.; Pedersen, Mogens Theisen;

    2013-01-01

    Introduction: We investigated muscle activation strategy and performance of knee extensor and flexor muscles in children and adults with generalized joint hypermobility (GJH) and compared them with controls. Methods: Muscle activation, torque steadiness, electromechanical delay, and muscle strength...... was greater in GJH during knee flexion compared with controls. Torque steadiness was impaired in adults with GJH during knee flexion. No effect of GJH was found on muscle strength or electromechanical delay. Correlation analysis revealed an association between GJH severity and function in adults. Conclusions...... were evaluated in 39 children and 36 adults during isometric knee extension and flexion. Subjects performed isometric maximum contractions, submaximal contractions at 25% maximum voluntary contraction (MVC), and explosive contractions. Results: Agonist activation was reduced, and coactivation ratio...

  17. Testosterone reduces knee passive range of motion and expression of relaxin receptor isoforms via 5α-dihydrotestosterone and androgen receptor binding.

    Science.gov (United States)

    Dehghan, Firouzeh; Muniandy, Sekaran; Yusof, Ashril; Salleh, Naguib

    2014-01-01

    Ovarian steroids such as estrogen and progesterone have been reported to influence knee laxity. The effect of testosterone, however, remains unknown. This study investigated the effect of testosterone on the knee range of motion (ROM) and the molecular mechanisms that might involve changes in the expression of relaxin receptor isoforms, Rxfp1 and Rxfp2 in the patella tendon and lateral collateral ligament of the female rat knee. Ovariectomized adult female Wistar rats received three days treatment with peanut oil (control), testosterone (125 and 250 μg/kg) and testosterone (125 and 250 μg/kg) plus flutamide, an androgen receptor blocker or finasteride, a 5α-reductase inhibitor. Duplicate groups received similar treatment however in the presence of relaxin (25 ng/kg). A day after the last drug injection, knee passive ROM was measured by using a digital miniature goniometer. Both tendon and ligament were harvested and then analysed for protein and mRNA expression for Rxfp1 and Rxfp2 respectively. Knee passive ROM, Rxfp1 and Rxfp2 expression were significantly reduced following treatment with testosterone. Flutamide or finasteride administration antagonized the testosterone effect. Concomitant administration of testosterone and relaxin did not result in a significant change in knee ROM as compared to testosterone only treatment; however this was significantly increased following flutamide or finasteride addition. Testosterone effect on knee passive ROM is likely mediated via dihydro-testosterone (DHT), and involves downregulation of Rxfp1 and Rxfp2 expression, which may provide the mechanism underlying testosterone-induced decrease in female knee laxity. PMID:24642882

  18. Testosterone Reduces Knee Passive Range of Motion and Expression of Relaxin Receptor Isoforms via 5α-Dihydrotestosterone and Androgen Receptor Binding

    Directory of Open Access Journals (Sweden)

    Firouzeh Dehghan

    2014-03-01

    Full Text Available Ovarian steroids such as estrogen and progesterone have been reported to influence knee laxity. The effect of testosterone, however, remains unknown. This study investigated the effect of testosterone on the knee range of motion (ROM and the molecular mechanisms that might involve changes in the expression of relaxin receptor isoforms, Rxfp1 and Rxfp2 in the patella tendon and lateral collateral ligament of the female rat knee. Ovariectomized adult female Wistar rats received three days treatment with peanut oil (control, testosterone (125 and 250 μg/kg and testosterone (125 and 250 μg/kg plus flutamide, an androgen receptor blocker or finasteride, a 5α-reductase inhibitor. Duplicate groups received similar treatment however in the presence of relaxin (25 ng/kg. A day after the last drug injection, knee passive ROM was measured by using a digital miniature goniometer. Both tendon and ligament were harvested and then analysed for protein and mRNA expression for Rxfp1 and Rxfp2 respectively. Knee passive ROM, Rxfp1 and Rxfp2 expression were significantly reduced following treatment with testosterone. Flutamide or finasteride administration antagonized the testosterone effect. Concomitant administration of testosterone and relaxin did not result in a significant change in knee ROM as compared to testosterone only treatment; however this was significantly increased following flutamide or finasteride addition. Testosterone effect on knee passive ROM is likely mediated via dihydro-testosterone (DHT, and involves downregulation of Rxfp1 and Rxfp2 expression, which may provide the mechanism underlying testosterone-induced decrease in female knee laxity.

  19. Role of flexors in knee stability.

    Science.gov (United States)

    Chen, C Y; Jiang, C C; Jan, M H; Lai, J S

    1995-05-01

    The muscle strength of knee extensors is commonly used as an indicator of a patient's functional recovery following reconstruction of the anterior cruciate ligament (ACL). The knee flexors are dynamic stabilizers that prevent tibial anterior displacement and may reinforce the function of the ACL. The purpose of this study was to examine the relationship of knee flexor performance assessed by isokinetic dynamometer and clinical evaluations including KT-1000 stability tests, shuttle run tests, thigh and calf circumference and range of motion of the knee joint. Ten patients who received ACL reconstruction over a 3- to 5-year period were included in this study, as were 15 normal controls who were tested for comparison. There was no significant difference in the time taken for the shuttle run test between normal controls and patients who underwent ACL, but there was a positive correlation between the shuttle run test and laxity of the knee joint. The knee laxity of ACL patients was significantly greater than that of the normal controls under passive anterior force. However, no significant difference was seen in the stability test under active contraction of the knee extensors. In addition, a positive correlation was seen between the KT-1000 knee ligament arthrometry test results and both torque acceleration energy and the average power of the flexors. These results suggest that physical therapy for patients following ACL reconstruction should emphasize the explosiveness of knee flexors to help strengthen the dynamic stability of the knee joint and motor performance.

  20. An ex vivo continuous passive motion model in a porcine knee for assessing primary stability of cell-free collagen gel plugs

    Directory of Open Access Journals (Sweden)

    El-Zayat Bilal

    2010-12-01

    Full Text Available Abstract Background Primary stability of cartilage repair constructs is of the utmost importance in the clinical setting but few continuous passive motion (CPM models are available. Our study aimed to establish a novel ex vivo CPM animal model and to evaluate the required motion cycles for testing the mechanical properties of a new cell-free collagen type I gel plug (CaReS®-1S. Methods A novel ex vivo CPM device was developed. Full-thickness cartilage defects (11 mm diameter by 6 mm deep were created on the medial femoral condyle of porcine knee specimens. CaReS®-1S was implanted in 16 animals and each knee underwent continuous passive motion. After 0, 2000, 4000, 6000, and 8000 motions, standardized digital pictures of the grafts were taken, focusing on the worn surfaces. The percentage of worn surface on the total CaReS®-1S surface was evaluated with image processing software. Results Significant differences in the worn surface were recorded between 0 and 2000 motion cycles (p ®-1S with an empty defect site was recorded. Conclusion The ex vivo CPM animal model is appropriate in investigating CaReS®-1S durability under continuous passive motion. 2000 motion cycles appear adequate to assess the primary stability of type I collagen gels used to repair focal chondral defects.

  1. Acute effects of instrument assisted soft tissue mobilization vs. foam rolling on knee and hip range of motion in soccer players.

    Science.gov (United States)

    Markovic, Goran

    2015-10-01

    The aim of the present investigation was to evaluate the acute effects of foam rolling (FR) and a new form of instrument-assisted soft tissue mobilization (IASTM), Fascial Abrasion Technique ™ (FAT) on hip and knee range of motion in soccer players. Twenty male soccer players randomly allocated into FR and FAT group (n = 10 each). Passive knee flexion and straight leg raise tests were measured before, immediately after and 24 h after intervention (FR or FAT). The FR group applied a 2-min quadriceps and hamstrings rolling, while FAT group received a 2-min application of FAT to the quadriceps and hamstrings muscles. Both groups significantly improved knee and hip ROM (p Fascial Abrasion Technique ™ and FR for increasing lower extremity ROM of athletes. PMID:26592226

  2. Effect of gait retraining for reducing ambulatory knee load on trunk biomechanics and trunk muscle activity.

    Science.gov (United States)

    Nüesch, Corina; Laffer, Dominik; Netzer, Cordula; Pagenstert, Geert; Mündermann, Annegret

    2016-06-01

    The purpose of this study was to test the hypothesis that walking with increased medio-lateral trunk sway is associated with lower external knee adduction moment and lower extremity muscle activation, and higher external ipsilateral trunk moment and trunk muscle activity than walking with normal trunk sway in healthy participants. Fifteen participants performed walking trials with normal and increased medio-lateral trunk sway. Maximum trunk sway, first maximum knee adduction moment, lateral trunk bending moment, and bilateral vastus medialis, vastus lateralis, gluteus medius, rectus abdominis, external oblique and erector spinae muscle activity were computed. Walking with increased trunk sway was associated with lower maximum knee adduction moment (95% confidence interval (CI): 0.50-0.62Nm/kg vs. 0.62-0.76Nm/kg; P<.001) and ipsilateral gluteus medius (-17%; P=.014) and erector spinae muscle activity (-24%; P=.004) and greater maximum lateral trunk bending moment (+34%; P<.001) and contralateral external oblique muscle activity (+60%; P=.009). In all participants, maximum knee adduction moment was negatively correlated and maximum trunk moment was positively correlated with maximum trunk sway. The results of this study suggest that walking with increased trunk sway not only reduces the external knee adduction moment but also alters and possibly increases the load on the trunk. Hence, load-altering biomechanical interventions should always be evaluated not only regarding their effects on the index joint but on other load-bearing joints such as the spine. PMID:27264398

  3. Design and control of a prosthetic leg for above-knee amputees operated in semi-active and active modes

    Science.gov (United States)

    Park, Jinhyuk; Yoon, Gun-Ha; Kang, Je-Won; Choi, Seung-Bok

    2016-08-01

    This paper proposes a new prosthesis operated in two different modes; the semi-active and active modes. The semi-active mode is achieved from a flow mode magneto-rheological (MR) damper, while the active mode is obtained from an electronically commutated (EC) motor. The knee joint part of the above knee prosthesis is equipped with the MR damper and EC motor. The MR damper generates reaction force by controlling the field-dependent yield stress of the MR fluid, while the EC motor actively controls the knee joint angle during gait cycle. In this work, the MR damper is designed as a two-end type flow mode mechanism without air chamber for compact size. On other hand, in order to predict desired knee joint angle to be controlled by EC motor, a polynomial prediction function using a statistical method is used. A nonlinear proportional-derivative controller integrated with the computed torque method is then designed and applied to both MR damper and EC motor to control the knee joint angle. It is demonstrated that the desired knee joint angle is well achieved in different walking velocities on the ground ground.

  4. Vitality and the course of limitations in activities in osteoarthritis of the hip or knee

    Directory of Open Access Journals (Sweden)

    van Dijk Gabriella M

    2011-11-01

    Full Text Available Abstract Background The objective of the study was to determine whether psychological and social factors predict the course of limitations in activities in elderly patients with osteoarthritis of the hip or knee, in addition to established somatic and cognitive risk factors. Methods A longitudinal cohort study with a follow-up period of three years was conducted. Patients (N = 237 with hip or knee osteoarthritis were recruited from rehabilitation centers and hospitals. Body functions, comorbidity, cognitive functioning, limitations in activities and psychological and social factors (mental health, vitality, pain coping and perceived social support were assessed. Statistical analyses included univariate and multivariate regression analyses. Psychological and social factors were added to a previously developed model with body functions, comorbidity and cognitive functioning. Results In knee OA, low vitality has a negative impact on the course of self-reported and performance-based limitations in activities, after controlling for somatic and cognitive factors. In hip OA, psychological and social factors had no additional contribution to the model. Conclusion Low vitality predicts deterioration of limitations in activities in elderly patients with osteoarthritis of the knee, in addition to established somatic and cognitive risk factors. However, the contribution of vitality is relatively small. Results of this study are relevant for the group of patients with knee or hip OA, attending hospitals and rehabilitation centers.

  5. Perceived causality influences brain activity evoked by biological motion.

    Science.gov (United States)

    Morris, James P; Pelphrey, Kevin A; McCarthy, Gregory

    2008-01-01

    Using functional magnetic resonance imaging (fMRI), we investigated brain activity in an observer who watched the hand and arm motions of an individual when that individual was, or was not, the cause of the motion. Subjects viewed a realistic animated 3D character who sat at a table containing four pistons. On Intended Motion trials, the character raised his hand and arm upwards. On Unintended Motion trials, the piston under one of the character's hands pushed the hand and arm upward with the same motion. Finally, during Non-Biological Motion control trials, a piston pushed a coffee mug upward in the same smooth motion. Hand and arm motions, regardless of intention, evoked significantly more activity than control trials in a bilateral region that extended ventrally from the posterior superior temporal sulcus (pSTS) region and which was more spatially extensive in the right hemisphere. The left pSTS near the temporal-parietal junction, robustly differentiated between the Intended Motion and Unintended Motion conditions. Here, strong activity was observed for Intended Motion trials, while Unintended Motion trials evoked similar activity as the coffee mug trials. Our results demonstrate a strong hemispheric bias in the role of the pSTS in the perception of causality of biological motion. PMID:18633843

  6. Changes in the activity of trunk and hip extensor muscles during bridge exercises with variations in unilateral knee joint angle

    Science.gov (United States)

    Kim, Juseung; Park, Minchul

    2016-01-01

    [Purpose] This study compared abdominal and hip extensor muscle activity during a bridge exercise with various knee joint angles. [Subjects and Methods] Twenty-two healthy male subjects performed a bridge exercise in which the knee joint angle was altered. While subjects performed the bridge exercise, external oblique, internal oblique, gluteus maximus, and semitendinosus muscle activity was measured using electromyography. [Results] The bilateral external and internal oblique muscle activity was significantly higher at 0° knee flexion compared to 120°, 90°, and 60°. The bilateral gluteus maximus muscle activity was significantly different at 0° of knee flexion compared to 120°, 90°, and 60°. The ipsilateral semitendinosus muscle activity was significantly increased at 90° and 60° of knee flexion compared to 120°, and significantly decreased at 0° knee flexion compared with 120°, 90°, and 60°. The contralateral semitendinosus muscle activity was significantly higher at 60° of knee flexion than at 120°, and significantly higher at 0° of knee flexion than at 120°, 90°, and 60°. [Conclusion] Bridge exercises performed with knee flexion less than 90° may be used to train the ipsilateral semitendinosus. Furthermore, bridge exercise performed with one leg may be used to train abdominal and hip extensor muscles. PMID:27799688

  7. Single- vs. double-bundle anterior cruciate ligament reconstruction: a new aspect of knee assessment during activities involving dynamic knee rotation.

    Science.gov (United States)

    Czamara, Andrzej; Królikowska, Aleksandra; Szuba, Łukasz; Widuchowski, Wojciech; Kentel, Maciej

    2015-02-01

    Few studies have compared single-bundle (SB) and double-bundle (DB) anterior cruciate ligament reconstruction (ACLR) in the knee joint during activities involving change-of-direction maneuvers and knee rotation. This study examined whether the type of ACLR contributes to postphysiotherapy outcomes, with an emphasis on knee function assessment during activities involving dynamic knee rotation. Fifteen male patients after SB ACLR and 15 male patients after DB ACLR took part in the same physiotherapy program. Twenty-four weeks after ACLR, both groups underwent anterior laxity measurement, pivot shift tests, range of movement and joint circumference measurements, subjective assessment of pain and stability levels in the knee joint, peak torque measurement of the muscles rotating the tibia toward the femur, and a run test with maximal speed and change-of-direction maneuvers. Comparative analysis did not show any differences between the results of anterior tibial translation, pivot shift test, range of movement and joint circumference, and subjective assessment of pain and knee joint stability levels. No differences were noted between the groups in peak torque values obtained from the muscles responsible for internal and external tibial rotation or results of the run test. The data obtained from this study can be used by research teams to monitor and compare the effectiveness of various study protocols involving surgical and physiotherapy treatment. The data are especially useful when combined with the clinical assessment of patients who would like to return to sport.

  8. Physical Activity Participation Among Patients After Total Hip and Knee Arthroplasty

    NARCIS (Netherlands)

    Stevens, Martin; Reininga, Inge H. F.; Bulstra, Sjoerd K.; Wagenmakers, Robert; van den Akker-Scheek, Inge

    2012-01-01

    Total hip (THA) and knee arthroplasty (TKA) are successful operative interventions, yet little is known about the physical activity behavior of patients after THA/TKA. For older adults, there are beneficial effects of regular physical activity after THA/TKA. The objective of this paper is to review

  9. Small increase of actual physical activity 6 months after total hip or knee arthroplasty

    NARCIS (Netherlands)

    I.B. de Groot (Ingrid); J.B.J. Bussmann (Hans); H.J. Stam (Henk); J.A.N. Verhaar (Jan)

    2008-01-01

    textabstractLimitation in daily physical activity is one of the reasons for total hip arthroplasty (THA) or total knee arthroplasty (TKA). However, studies of the effects of THA or TKA generally do not determine actual daily activity as part of physical functioning. We determined the effect of THA o

  10. Robotic Assistance of Human Motion using Active-backdrivability on a Geared Electromagnetic Motor

    Directory of Open Access Journals (Sweden)

    Mario Jorge Claros

    2016-03-01

    bandwidth and also providing controllable assistance and resistance forces to the user’s movements, without the use of any biological signal. Validation of the proposed approach is shown by the construction of a powered orthosis for the knee, used to test the system’s performance under real human motion conditions. The proposed system was tested on one healthy subject by measuring electromyographic levels both with and without the orthosis, under controlled flexion and extension cycles. Experimental results demonstrate the effectiveness of the proposed approach in detecting the user’s intentions regarding motion, reducing and increasing muscular activity when configured for assistance and resistance, respectively, and also increasing the transparency of the actuation system when perfect tracking of the limbs is needed.

  11. The in vivo assessment of tibial motion in the transverse plane in anterior cruciate ligament-reconstructed knees.

    Science.gov (United States)

    Nordt, W E; Lotfi, P; Plotkin, E; Williamson, B

    1999-01-01

    Twenty-one knees with acutely injured anterior cruciate ligaments were reconstructed with patellar tendon autografts. Eight of the knees had concomitant medial ligament injuries that were not addressed surgically. Follow-up evaluation (average, 25 months) included computed tomography measurements to analyze transverse-plane laxity in both translation and rotation. These measurements were performed with the patient's leg in a load cell device that stabilizes the distal femur and applies known anterior translational force to the proximal tibia at approximately 20 degrees of flexion. A torque apparatus was used to apply internal and external rotational torque to the leg. Images of the tibial plateau in neutral, internal, and external rotation were performed, with and without an anterior translational force. Both knees of each patient were tested and categorized as group I (anterior cruciate ligament-reconstructed) or group II (uninjured). Translation as measured by computed tomography averaged 1 mm side-to-side difference. Internal rotation averaged 8.7 degrees in group I knees and 10.8 degrees in group II knees. External rotation averaged 9.1 degrees in group I knees and 7.4 degrees in group II knees. The eight knees with concomitant medial ligament injuries were analyzed separately; external rotation without anterior load in group I was 9.5 degrees, compared with 5 degrees in group II. This difference was significant (P < 0.01). PMID:10496578

  12. Women with knee osteoarthritis have more pain and poorer function than men, but similar physical activity prior to total knee replacement

    Directory of Open Access Journals (Sweden)

    Tonelli Shalome M

    2011-11-01

    Full Text Available Abstract Background Osteoarthritis of the knee is a major clinical problem affecting a greater proportion of women than men. Women generally report higher pain intensity at rest and greater perceived functional deficits than men. Women also perform worse than men on function measures such as the 6-minute walk and timed up and go tests. Differences in pain sensitivity, pain during function, psychosocial variables, and physical activity levels are unclear. Further the ability of various biopsychosocial variables to explain physical activity, function and pain is unknown. Methods This study examined differences in pain, pain sensitivity, function, psychosocial variables, and physical activity between women and men with knee osteoarthritis (N = 208 immediately prior to total knee arthroplasty. We assessed: (1 pain using self-report measures and a numerical rating scale at rest and during functional tasks, (2 pain sensitivity using quantitative sensory measures, (3 function with self-report measures and specific function tasks (timed walk, maximal active flexion and extension, (4 psychosocial measures (depression, anxiety, catastrophizing, and social support, and (5 physical activity using accelerometry. The ability of these mixed variables to explain physical activity, function and pain was assessed using regression analysis. Results Our findings showed significant differences on pain intensity, pain sensitivity, and function tasks, but not on psychosocial measures or physical activity. Women had significantly worse pain and more impaired function than men. Their levels of depression, anxiety, pain catastrophizing, social support, and physical activity, however, did not differ significantly. Factors explaining differences in (1 pain during movement (during gait speed test were pain at rest, knee extension, state anxiety, and pressure pain threshold; (2 function (gait speed test were sex, age, knee extension, knee flexion opioid medications, pain

  13. Loading of the knee joint during activities of daily living measured in vivo in five subjects.

    Science.gov (United States)

    Kutzner, I; Heinlein, B; Graichen, F; Bender, A; Rohlmann, A; Halder, A; Beier, A; Bergmann, G

    2010-08-10

    Detailed knowledge about loading of the knee joint is essential for preclinical testing of implants, validation of musculoskeletal models and biomechanical understanding of the knee joint. The contact forces and moments acting on the tibial component were therefore measured in 5 subjects in vivo by an instrumented knee implant during various activities of daily living. Average peak resultant forces, in percent of body weight, were highest during stair descending (346% BW), followed by stair ascending (316% BW), level walking (261% BW), one legged stance (259% BW), knee bending (253% BW), standing up (246% BW), sitting down (225% BW) and two legged stance (107% BW). Peak shear forces were about 10-20 times smaller than the axial force. Resultant forces acted almost vertically on the tibial plateau even during high flexion. Highest moments acted in the frontal plane with a typical peak to peak range -2.91% BWm (adduction moment) to 1.61% BWm (abduction moment) throughout all activities. Peak flexion/extension moments ranged between -0.44% BWm (extension moment) and 3.16% BWm (flexion moment). Peak external/internal torques lay between -1.1% BWm (internal torque) and 0.53% BWm (external torque). The knee joint is highly loaded during daily life. In general, resultant contact forces during dynamic activities were lower than the ones predicted by many mathematical models, but lay in a similar range as measured in vivo by others. Some of the observed load components were much higher than those currently applied when testing knee implants.

  14. Effect of shoes containing nanosilica particles on knee valgus in active females during landing

    Directory of Open Access Journals (Sweden)

    Zahra Bassiri

    2015-01-01

    Full Text Available Objective(s: The effect of silica nanoparticles (SNPs in sport shoes outsoles on the  parameters related to anterior cruciate ligament (ACL Injury has not been investigated. The aim of this study was to investigate the effect of shoes outsole containing a composite of thermoplastic elastomer based on styrene-butadiene and silica nanoparticles (TPEN shoe on Knee Valgus Angle (KVA as a risk factor of ACL injuries during landing Materials and Methods: Fourteen active healthy women without knee injuries and disorders performed bilateral drop jump (DJ and single leg drop landing (SLL tasks in barefoot, wearing shoes fabricated with polyvinyl chloride outsole (PVC shoe and TPEN shoes conditions , randomly. The knee valgus angle values of right and left legs were calculated in the landing conditions. Two factors repeated measures ANOVA were used to investigate the effect of landing and footwear conditions on KVA of right and left legs.  Results: For both left and right limbs, the KVA was at maximum and minimum values during landing with barefoot and TPEN shoes, respectively. PVC shoe significantly reduced the knee valgus by 3.84% in left and 4.18% in right knee (P

  15. Prevention and management of knee osteoarthritis and knee cartilage injury in sports

    OpenAIRE

    Takeda, Hideki; NAKAGAWA, TAKUMI; Nakamura, Kozo; Engebretsen, Lars

    2011-01-01

    Articular cartilage defects in the knee of young or active individuals remain a problem in orthopaedic practice. These defects have limited ability to heal and may progress to osteoarthritis. The prevalence of knee osteoarthritis among athletes is higher than in the non-athletic population. The clinical symptoms of osteoarthritis are joint pain, limitation of range of motion and joint stiffness. The diagnosis of osteoarthritis is confirmed by the symptoms and the radiological findings (narrow...

  16. Prospective Randomized Trial of the Efficacy of Continuous Passive Motion Post Total Knee Arthroplasty: Experience of the Hospital for Special Surgery.

    Science.gov (United States)

    Joshi, Rupali N; White, Peter B; Murray-Weir, Mary; Alexiades, Michael M; Sculco, Thomas P; Ranawat, Amar S

    2015-12-01

    Conflicting evidence has created substantial controversy regarding the use of continuous passive motion (CPM) in the in-patient setting post total knee arthroplasty (TKA). A total of 109 patients were randomly assigned to two groups, CPM or no CPM, applied after TKA. All patients received the same physical therapy protocol (3 sessions per day), with the only exception being the CPM. Both groups had a knee flexion of 115° at 6 weeks and 120° at 3 months, with no significant differences (P=0.69 and P=0.41, respectively). Length of stay was significantly less for the group who did not receive CPM. The use of CPM had no clinically relevant benefits with respect to AROM, clinical outcomes or discharge disposition and was associated with a cost of $235.50 per TKA.

  17. Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance

    DEFF Research Database (Denmark)

    Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H;

    2012-01-01

    While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps muscle during 10-RM ...... knee-extensions performed with elastic tubing and an isotonic strength training machine....

  18. Which patients with osteoarthritis of hip and/or knee benefit most from behavorial graded activity?

    NARCIS (Netherlands)

    Veenhof, C.; Ende, C.H.M. van den; Dekker, J.; Köke, A.J.A.; Oostendorp, R.A.; Bijlsma, J.W.J.

    2007-01-01

    Our objective was to investigate whether behavioral graded activity (BGA) has particular benefit in specific subgroups of osteoarthritis (OA) patients. Two hundred participants with OA of hip or knee, or both (clinical American College of Rheumatology, ACR, criteria) participated in a randomized cli

  19. Which patients with osteoarthritis of hip and/or knee benefit most from behavioral graded activity?

    NARCIS (Netherlands)

    Veenhof, C.; Ende, C.H.M. van den; Dekker, J.; Kiike, A.J.; Oostendorp, R.A.B.; Bijlsma, J.W.J.

    2007-01-01

    Our objective was to investigate whether behavioral graded activity (BGA) has particular benefit in specific subgroups of osteoarthritis (OA) patients. Two hundred participants with OA of hip or knee, or both (clinical American College of Rheumatology, ACR, criteria) participated in a randomized cli

  20. Muscle strength, physical performance and physical activity as predictors of future knee replacement

    DEFF Research Database (Denmark)

    Skou, Søren T; Wise, Barton L; Lewis, Cora E;

    2016-01-01

    % CI) 0.99 (0.99 to 1.00)), but not when adjusting for Kellgren-Lawrence grade (p = 0.97). CONCLUSION: Lower levels of chair stand performance and self-reported physical activity are not associated with an increased risk of KR within 7 years, while the independent effect of knee extensor strength...

  1. Medium-term evaluation of total knee arthroplasty without patellar replacement

    Directory of Open Access Journals (Sweden)

    José Wanderley Vasconcelos

    2013-06-01

    Full Text Available OBJECTIVE: To mid-term evaluate patients who were submitted to total knee arthroplasty without patellar resurfacing. METHODS: It was realized a retrospective cross-sectional study of patients who were submitted to total knee arthroplasty without patellar resurfacing. In all patients clinical examination was done based on the protocol of the Knee Society Scoring System, which assessed pain, range of motion, stability, contraction, knee alignment and function, and radiological evaluation. RESULTS: A total of 36 patients were evaluated. Of these, 07 were operated only on left knee, 12 only on right knee and 17 were operated bilaterally, totaling 53 knees. Ages ranged from 26 to 84 years. Of the 53 knees evaluated, 33 (62.26% had no pain. The maximum flexion range of motion averaged 104.7°. No knee had difficulty in active extension. As to the alignment for anatomical axis twelve knees (22.64% showed deviation between 0° and 4° varus. Thirty-nine (75.49% knees showed pace without restriction and the femorotibial angle ranged between 3° varus and 13° valgus with an average of 5° valgus. The patellar index ranged from 0.2 to 1.1. CONCLUSION: Total knee arthroplasty whitout patellar resurfacing provides good results in mid-term evaluation.

  2. 人工全膝关节置换后关节活动度影响因素的研究趋势%Research trend of factors influencing range of motion after artificial total knee replacement

    Institute of Scientific and Technical Information of China (English)

    王九辉

    2012-01-01

    背景:人工全膝关节置换后关节活动度是评价患者对治疗是否满意的关键,是患者膝关节功能恢复的主要观察指标.目的:分析人工全膝关节置换后关节活动度研究领域的发展趋势,探讨人工全膝关节置换后关节活动度的影响因素.方法:由作者用计算机检索CNKI数据库2002/2011收录的有关人工全膝关节置换后关节活动度的相关文献,检索时间为2002/2011,中文检索词为"膝关节,人工关节,人工假体,关节活动度",英文检索词为"knee,artificial joint,prosthesis,range of motion".共检索到244篇文章,按纳入标准和排除标准对文献进行筛选和分析,共纳入211篇文章.从膝关节置换前膝关节活动度、人工假体类型和置换后康复训练等方面来分析其影响因素.结果与结论:近10年来,CNKI数据库学术期刊收录膝关节置换后关节活动度研究文献数量呈上升趋势,2010年发表文献量最多为38篇,占总文献量的18.0%;从检索的关键词可见膝关节置换在骨关节炎疾病的治疗中应用最多;相关研究文献的基金资助项目较少;<中国组织工程研究与临床康复>杂志因设有硬组织植入物栏目,发表的相关文献量最多为41篇,占全部文献量的19.4%.文献计量学的分析为中国从事人工全膝关节置换的临床医务工作者提供更有价值的参考信息,影响人工全膝关节置换后关节活动度因素有很多,而且存在很多争议,临床医生应该不断提高治疗技术和康复训练方法,尽可能的恢复患者的膝关节活动功能.%BACKGROUND: Range of motion after artificial total knee replacement is the key to evaluate whether the patients are satisfied with the treatment or not, as well as the main outcome measures of functional recovery of joint knee.OBJECTIVE: To analyze the trends in the field of joint activity after artificial total knee replacement and to explore the influence factors of joint activity

  3. The effects of lower extremity muscle activation and passive range of motion on single leg squat performance.

    Science.gov (United States)

    Mauntel, Timothy C; Begalle, Rebecca L; Cram, Tyler R; Frank, Barnett S; Hirth, Christopher J; Blackburn, Troy; Padua, Darin A

    2013-07-01

    Knee valgus is a potential risk factor for lower extremity (LE) injuries. Clinical movement screenings and passive range of motion (PROM) measurements may help identify neuromuscular patterns, which contribute to knee valgus. The purpose of this study was to compare LE muscle activation and PROM between subjects who display visual medial knee displacement (MKD) during a single leg squat (SLS) and those who do not. We hypothesized that muscular activation and PROM would differ between the groups. Forty physically active adults (20 controls, 20 MKDs) participated in this study. Subjects completed 10 LE PROM assessments and performed 5 SLS trials while electromyography (EMG) data were collected from 8 LE muscles. Three separate multivariate analysis of variance were used to identify group differences in EMG data, muscle coactivation, and PROM. Results during the SLS indicated hip coactivation ratios revealed smaller gluteus medius to hip adductor (GMed:Hip Add) (p = 0.028) and gluteus maximus to hip adductor (GMax:Hip Add) coactivation ratios (p = 0.007) compared with the control group. Also, the MKD group displayed significantly less passive ankle dorsiflexion with the knee extended (p = 0.047) and flexed (p = 0.034), and greater talar glide motion (p = 0.012). The findings of this study indicate that MKD during a SLS seems to be influenced by decreased coactivation of the gluteal to the hip adductor muscles and restricted dorsiflexion. Therefore, conditioning, rehabilitation, and injury prevention programs should focus on decreasing hip adductor activity, increasing hip abductor and external rotator activity, and increasing ankle dorsiflexion in hopes to decrease the incidence of these injuries. PMID:23096063

  4. [What are the recommendations for sport activity following total hip or total knee arthroplasty?].

    Science.gov (United States)

    Tsur, Azmon; Volpin, Gershon

    2013-11-01

    Total hip and knee arthroplasty are surgical procedures usually performed in older adults aged 65-70 years and more, who suffer from arthritic joint degeneration, in order to relieve pain and improve functioning. In the past decade there have been more and more documentations of younger people, 50-60 years old and even less, who expect to participate in physical activity following these procedures. The trend today is to recommend activities which exert mild pressure on the implants such as swimming, cycling, golf, bowling, walking and cycling. It is not recommended to participate in sports activities that place greater pressure on the implants such as soccer, football, volleyball, handball, basketball, hockey and jogging. Such high-stress activities may cause early loosening of implants, as described in the article by Keren et al. in this issue: "Sport activity after hip and knee arthroplasty". PMID:24416821

  5. Motion Geometric Active Contours: Tracking Nonrigid Objects in Clutter Background

    Institute of Scientific and Technical Information of China (English)

    Cen Feng (岑峰); Qi Feihu

    2003-01-01

    MGAC (Motion Geometric Active Contours), a new variational framework of geometric active contours to track multiple nonrigid moving objects in the clutter background in image sequences is presented. This framework, incorporating with the motion edge information, consists of motion detection and tracking stages. At the motion detection stage, the motion edge map provides an approximate edge map of the moving objects. Then, a tracking stage, merely using the static edge information, is considered to improve the motion detection result. Force field regularization method is used to extend the capture range of the edge attraction force field in both stages. Experiments demonstrate that the proposed framework is valid for tracking multiple nonrigid objects in the clutter background.

  6. Voluntary activation of human knee extensors measured using transcranial magnetic stimulation.

    Science.gov (United States)

    Goodall, S; Romer, L M; Ross, E Z

    2009-09-01

    The aim of this study was to determine the applicability and reliability of a transcranial magnetic stimulation twitch interpolation technique for measuring voluntary activation of a lower limb muscle group. Cortical voluntary activation of the knee extensors was determined in nine healthy men on two separate visits by measuring superimposed twitch torques evoked by transcranial magnetic stimulation during isometric knee extensions of varying intensity. Superimposed twitch amplitude decreased linearly with increasing voluntary torque between 50 and 100% of mean maximal torque, allowing estimation of resting twitch amplitude and subsequent calculation of voluntary activation. There were no systematic differences for maximal voluntary activation within day (mean +/- s.d. 90.9 +/- 6.2 versus 90.7 +/- 5.9%; P = 0.98) or between days (90.8 +/- 6.0 versus 91.2 +/- 5.7%; P = 0.92). Systematic bias and random error components of the 95% limits of agreement were 0.23 and 9.3% within day versus 0.38 and 7.5% between days. Voluntary activation was also determined immediately after a 2 min maximal voluntary isometric contraction; in four of these subjects, voluntary activation was determined 30 min after the sustained contraction. Immediately after the sustained isometric contraction, maximal voluntary activation was reduced from 91.2 +/- 5.7 to 74.2 +/- 12.0% (P knee extensors.

  7. Two Different Protocols for Knee Joint Motion Analyses in the Stance Phase of Gait: Correlation of the Rigid Marker Set and the Point Cluster Technique

    Directory of Open Access Journals (Sweden)

    Takashi Fukaya

    2012-01-01

    Full Text Available Objective. There are no reports comparing the protocols provided by rigid marker set (RMS and point cluster technique (PCT, which are similar in terms of estimating anatomical landmarks based on markers attached to a segment. The purpose of this study was to clarify the correlation of the two different protocols, which are protocols for knee motion in gait, and identify whether measurement errors arose at particular periods during the stance phase. Methods. The study subjects were 10 healthy adults. All estimated anatomical landmarks were which their positions, calculated by each protocol of the PCT and RMS, were compared using Pearson’s product correlation coefficients. To examine the reliability of the angle changes of the knee joint measured by RMS and the PCT, the coefficient of multiple correlations (CMCs was used. Results. Although the estimates of the anatomical landmarks showed high correlations of >0.90 (<0.01 for the Y- and Z-coordinates, the correlations were low for the X-coordinates at all anatomical landmarks. The CMC was 0.94 for flexion/extension, 0.74 for abduction/adduction, and 0.71 for external/internal rotation. Conclusion. Flexion/extension and abduction/adduction of the knee by two different protocols had comparatively little error and good reliability after 30% of the stance phase.

  8. Self-reported activity level and knee function in amateur football players

    DEFF Research Database (Denmark)

    Frobell, R B; Svensson, E; Göthrick, M;

    2008-01-01

    ) amateur football players in 10 football clubs from each division below national level participated in the study. Self-reported Tegner Activity Scale, and the Knee injury and Osteoarthritis Outcome Score (KOOS) are the main outcome measures. Older age, female gender and lower level of competition (football...... is recommended. We suggest that self-reported Tegner Activity Scale scores should be adjusted for age, gender and level of competition. In amateur football players, KOOS scores do not need adjustment for age and gender....

  9. MUSCLE ACTIVITY RESPONSE TO EXTERNAL MOMENT DURING SINGLE-LEG DROP LANDING IN YOUNG BASKETBALL PLAYERS: THE IMPORTANCE OF BICEPS FEMORIS IN REDUCING INTERNAL ROTATION OF KNEE DURING LANDING

    Directory of Open Access Journals (Sweden)

    Meguru Fujii

    2012-06-01

    Full Text Available Internal tibial rotation with the knee close to full extension combined with valgus collapse during drop landing generally results in non-contact anterior cruciate ligament (ACL injury. The purpose of this study was to investigate the relationship between internal rotation of the knee and muscle activity from internal and external rotator muscles, and between the internal rotation of knee and externally applied loads on the knee during landing in collegiate basketball players. Our hypothesis was that the activity of biceps femoris muscle would be an important factor reducing internal knee rotation during landing. The subjects were 10 collegiate basketball students: 5 females and 5 males. The subjects performed a single-leg drop landing from a 25-cm height. Femoral and tibial kinematics were measured using a 3D optoelectronic tracking system during the drop landings, and then the knee angular motions were determined. Ground reaction forces and muscle activation patterns (lateral hamstring and medial hamstring were simultaneously measured and computed. Results indicated that lower peak internal tibial rotation angle at the time of landing was associated with greater lateral hamstring activity (r = -0.623, p < 0.001. When gender was considered, the statistically significant correlation remained only in females. There was no association between the peak internal tibial rotation angle and the knee internal rotation moment. Control of muscle activity in the lateral to medial hamstring would be an important factor in generating sufficient force to inhibit excessive internal rotation during landing. Strengthening the biceps femoris might mitigate the higher incidence of non-contact ACL injury in female athletes

  10. Strength training to contraction failure increases voluntary activation of the quadriceps muscle shortly after total knee arthroplasty

    DEFF Research Database (Denmark)

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders;

    2016-01-01

    (%EMGmax) and median power frequency of the EMG power spectrum were calculated for each repetition decile (10%-100% contraction failure). RESULTS: Muscle activity increased significantly over contractions from a mean of 90.0 and 93.6 %EMGmax (lateral vastus and medial vastus, respectively) at 10......OBJECTIVE: The objective of this study was to investigate voluntary activation of the quadriceps muscle during one set of knee extensions performed until contraction failure in patients shortly after total knee arthroplasty. DESIGN: This was a cross-sectional study of 24 patients with total knee...... arthroplasty. One set of knee extensions was performed until contraction failure, using a predetermined 10 repetition maximum loading. In the operated leg, electromyographic (EMG) activity of the lateral and medial vastus, semitendinosus, and biceps femoris muscles was recorded during the set. Muscle activity...

  11. Technology Efficacy in Active Prosthetic Knees for Transfemoral Amputees: A Quantitative Evaluation

    Directory of Open Access Journals (Sweden)

    Amr M. El-Sayed

    2014-01-01

    Full Text Available Several studies have presented technological ensembles of active knee systems for transfemoral prosthesis. Other studies have examined the amputees’ gait performance while wearing a specific active prosthesis. This paper combined both insights, that is, a technical examination of the components used, with an evaluation of how these improved the gait of respective users. This study aims to offer a quantitative understanding of the potential enhancement derived from strategic integration of core elements in developing an effective device. The study systematically discussed the current technology in active transfemoral prosthesis with respect to its functional walking performance amongst above-knee amputee users, to evaluate the system’s efficacy in producing close-to-normal user performance. The performances of its actuator, sensory system, and control technique that are incorporated in each reported system were evaluated separately and numerical comparisons were conducted based on the percentage of amputees’ gait deviation from normal gait profile points. The results identified particular components that contributed closest to normal gait parameters. However, the conclusion is limitedly extendable due to the small number of studies. Thus, more clinical validation of the active prosthetic knee technology is needed to better understand the extent of contribution of each component to the most functional development.

  12. Effect of the neuromuscular activation of knee extensors on vertical jump by using electrostimulation method

    OpenAIRE

    Bílý, Jiří; Cacek, Jan

    2014-01-01

    Neuromuscular electrical stimulation is one of the methods of strength development during which there is no voluntary muscle contraction. The aim of this study was to investigate the influence of the neuromuscular activation of knee extensors on vertical jump by using electrostimulation method. Ten healthy trained male students in sports-sciences, aged 21-25 years, perform Sargent jump test. They perform two kinds of jump - squat jump and drop jump (42 cm heigh bench) immediately after electr...

  13. 高空运动落地后对膝盖的冲击力学分析%Analysis of Knee Motion Force Parameters After Air Sport Landfall

    Institute of Scientific and Technical Information of China (English)

    孙斌

    2015-01-01

    传统方法构建的高空运动落体后对膝盖的冲击力学分析模型只能求解局部的膝关节受力和发力参数,对膝盖及下肢的各个关节驱动作用和受力冲击运动势能等参数求解建模困难.提出一种基于七连杆驱动结构的高空运动落体后的冲击动力学分析模型.构建人体在高空落地后的下肢膝盖的运动链数学模型,分析落地冲击对膝盖的运动链位姿变换关系,采用7连杆驱动结构对人体高空落地后的下肢进行7连杆结构分解,采用Lagrange动力学方程实现对冲击力学参数的全局分析,得出优化解向量.仿真结果表明,采用该受力分析模型,对膝盖冲击力的受力分析逼近于理论值,计算精度较高,性能优越,为体育训练和运动医疗提供准确的数据基础.%The impact of knee mechanics analysis model of high altitude exercise fall, driving torque and dynamic parame-ters of human lower limb joints, provides the model and the data base for the guidance of scientific sports training and sports medicine. Impact mechanics of knee motion analysis of high altitude falling after the traditional method of the knee joint model can solve the local force and force parameters of each joint, knee and lower limb function and the driving force of impact energy parameters modeling difficulty movement. An analysis model of driving air sports fall based on the struc-ture of the seven link rear impact dynamics is proposed. Construction at high altitude after landing leg knee motion of hu-man body even mathematical model, analysis the impact of the kinematic chain knee pose transformation relations, the 7 connecting rod to drive the structure of the human body at high altitude after the fall of the lower limb was decomposed 7 connecting rod structure, the dynamic equation of Lagrange to achieve the overall impact of mechanical parameters analy-sis, obtains the optimization solution vector. Simulation results show that the stress

  14. A conceptual framework for a sports knee injury performance profile (SKIPP and return to activity criteria (RTAC

    Directory of Open Access Journals (Sweden)

    David Logerstedt

    2015-10-01

    Full Text Available ABSTRACTInjuries to the knee, including intra-articular fractures, ligamentous ruptures, and meniscal and articular cartilage lesions, are commonplace within sports. Despite advancements in surgical techniques and enhanced rehabilitation, athletes returning to cutting, pivoting, and jumping sports after a knee injury are at greater risk of sustaining a second injury. The clinical utility of objective criteria presents a decision-making challenge to ensure athletes are fully rehabilitated and safe to return to sport. A system centered on specific indicators that can be used to develop a comprehensive profile to monitor rehabilitation progression and to establish return to activity criteria is recommended to clear athletes to begin a progressive and systematic approach to activities and sports. Integration of a sports knee injury performance profile with return to activity criteria can guide clinicians in facilitating an athlete's safe return to sport, prevention of subsequent injury, and life-long knee joint health.

  15. Sustained Rhythmic Brain Activity Underlies Visual Motion Perception in Zebrafish

    Directory of Open Access Journals (Sweden)

    Verónica Pérez-Schuster

    2016-10-01

    Full Text Available Following moving visual stimuli (conditioning stimuli, CS, many organisms perceive, in the absence of physical stimuli, illusory motion in the opposite direction. This phenomenon is known as the motion aftereffect (MAE. Here, we use MAE as a tool to study the neuronal basis of visual motion perception in zebrafish larvae. Using zebrafish eye movements as an indicator of visual motion perception, we find that larvae perceive MAE. Blocking eye movements using optogenetics during CS presentation did not affect MAE, but tectal ablation significantly weakened it. Using two-photon calcium imaging of behaving GCaMP3 larvae, we find post-stimulation sustained rhythmic activity among direction-selective tectal neurons associated with the perception of MAE. In addition, tectal neurons tuned to the CS direction habituated, but neurons in the retina did not. Finally, a model based on competition between direction-selective neurons reproduced MAE, suggesting a neuronal circuit capable of generating perception of visual motion.

  16. The effect of active sitting on trunk motion

    OpenAIRE

    Henry Wang; Kaitlyn J. Weiss; Mason C. Haggerty; Jacqueline E Heath

    2014-01-01

    Background: Prolonged sitting is a risk factor for low-back pain. The primary purpose of this study is to determine if prolonged active sitting will result in increased trunk motion. Methods: Fifteen healthy female participants volunteered to sit for 30 min on each of three surfaces including an air-cushion, a stability ball, and a hard surface. Trunk motion was monitored using a Vicon motion capture system, and foot center of pressure was collected with two AMTI force plates. Results: ...

  17. Fiducial marker-based correction for involuntary motion in weight-bearing C-arm CT scanning of knees. II. Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jang-Hwan [Department of Radiology, Stanford University, Stanford, California 94305 and Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Maier, Andreas; Keil, Andreas; McWalter, Emily J.; Gold, Garry E.; Fahrig, Rebecca [Department of Radiology, Stanford University, Stanford, California 94305 (United States); Pal, Saikat [Biomedical Engineering Department, California Polytechnic State University, San Luis Obispo, California 93407 (United States); Beaupré, Gary S. [Musculoskeletal Research Laboratory, VA Palo Alto Health Care System, Palo Alto, California 94304 (United States)

    2014-06-15

    Purpose: A C-arm CT system has been shown to be capable of scanning a single cadaver leg under loaded conditions by virtue of its highly flexible acquisition trajectories. In Part I of this study, using the 4D XCAT-based numerical simulation, the authors predicted that the involuntary motion in the lower body of subjects in weight-bearing positions would seriously degrade image quality and the authors suggested three motion compensation methods by which the reconstructions could be corrected to provide diagnostic image quality. Here, the authors demonstrate that a flat-panel angiography system is appropriate for scanning both legs of subjectsin vivo under weight-bearing conditions and further evaluate the three motion-correction algorithms using in vivo data. Methods: The geometry of a C-arm CT system for a horizontal scan trajectory was calibrated using the PDS-2 phantom. The authors acquired images of two healthy volunteers while lying supine on a table, standing, and squatting at several knee flexion angles. In order to identify the involuntary motion of the lower body, nine 1-mm-diameter tantalum fiducial markers were attached around the knee. The static mean marker position in 3D, a reference for motion compensation, was estimated by back-projecting detected markers in multiple projections using calibrated projection matrices and identifying the intersection points in 3D of the back-projected rays. Motion was corrected using three different methods (described in detail previously): (1) 2D projection shifting, (2) 2D deformable projection warping, and (3) 3D rigid body warping. For quantitative image quality analysis, SSIM indices for the three methods were compared using the supine data as a ground truth. Results: A 2D Euclidean distance-based metric of subjects’ motion ranged from 0.85 mm (±0.49 mm) to 3.82 mm (±2.91 mm) (corresponding to 2.76 to 12.41 pixels) resulting in severe motion artifacts in 3D reconstructions. Shifting in 2D, 2D warping, and 3D

  18. Controlling Knee Swing Initiation and Ankle Plantarflexion With an Active Prosthesis on Level and Inclined Surfaces at Variable Walking Speeds

    OpenAIRE

    ,

    2014-01-01

    Improving lower-limb prostheses is important to enhance the mobility of amputees. The purpose of this paper is to introduce an impedance-based control strategy (consisting of four novel algorithms) for an active knee and ankle prosthesis and test its generalizability across multiple walking speeds, walking surfaces, and users. The four algorithms increased ankle stiffness throughout stance, decreased knee stiffness during terminal stance, as well as provided powered ankle plantarflexion and k...

  19. Video summarization using descriptors of motion activity: a motion activity based approach to key-frame extraction from video shots

    Science.gov (United States)

    Divakaran, Ajay; Radhakrishnan, Regunathan; Peker, Kadir A.

    2001-10-01

    We describe a video summarization technique that uses motion descriptors computed in the compressed domain. It can either speed up conventional color-based video summarization techniques, or rapidly generate a key-frame based summary by itself. The basic hypothesis of the work is that the intensity of motion activity of a video segment is a direct indication of its `summarizability,' which we experimentally verify using the MPEG-7 motion activity descriptor and the fidelity measure proposed in H. S. Chang, S. Sull, and S. U. Lee, `Efficient video indexing scheme for content-based retrieval,' IEEE Trans. Circuits Syst. Video Technol. 9(8), (1999). Note that the compressed domain extraction of motion activity intensity is much simpler than the color-based calculations. We are thus able to quickly identify easy to summarize segments of a video sequence since they have a low intensity of motion activity. We are able to easily summarize these segments by simply choosing their first frames. We can then apply conventional color-based summarization techniques to the remaining segments. We thus speed up color-based summarization by reducing the number of segments processed. Our results also motivate a simple and novel key-frame extraction technique that relies on a motion activity based nonuniform sampling of the frames. Our results indicate that it can either be used by itself or to speed up color-based techniques as explained earlier.

  20. Does the GMFCS level influence the improvement in knee range of motion after rectus femoris transfer in cerebral palsy?

    Science.gov (United States)

    Blumetti, Francesco C; Morais Filho, Mauro C; Kawamura, Cátia M; Cardoso, Michelle O; Neves, Daniella L; Fujino, Marcelo H; Lopes, José Augusto F

    2015-09-01

    The aim of this study was to evaluate the influence of the Gross Motor Function Classification System (GMFCS) on the outcomes of rectus femoris transfer (RFT) for patients with cerebral palsy and stiff knee gait. We performed a retrospective review of patients seen at our gait laboratory from 1996 to 2013. Inclusion criteria were (i) spastic diplegic cerebral palsy, (ii) GMFCS levels I-III, (iii) reduced peak knee flexion in swing (PKFSwGMFCS levels I and II. In the non-RFT group, no improvement in KROM was observed in any GMFCS level. In this study, patients at GMFCS levels I and II were more likely to benefit from the RFT procedure.

  1. Rehabilitation of the arthrofibrotic knee.

    Science.gov (United States)

    Millett, Peter J; Johnson, Burt; Carlson, Jeff; Krishnan, Sumant; Steadman, J Richard

    2003-11-01

    This paper describes the postoperative rehabilitation of the arthrofibrotic knee, with specific emphasis on modern rehabilitation techniques. The significance of prevention and early recognition is discussed. The importance of early motion and patellar mobility is emphasized and specific exercises to prevent and treat stiffness are described. Continuous passive motion, bracing, and exercise--on the stationary bicycle, on the treadmill, and in water--are adjuncts in the program. Strengthening is added when motion is re-established and there is no swelling or pain. Sport-specific activities are added if progress is satisfactory and motion is maintained. If pain, swelling, or stiffness develops, exercises should be discontinued. Modalities such as cryotherapy, ultrasound, electrical stimulation, rest, and manipulation can be used judiciously. Anti-inflammatory and analgesic medications should be used to prevent inflammation, to control pain, and to allow more aggressive rehabilitative exercises. PMID:14653482

  2. Position-Specific Hip and Knee Kinematics in NCAA Football Athletes

    Science.gov (United States)

    Deneweth, Jessica M.; Pomeroy, Shannon M.; Russell, Jason R.; McLean, Scott G.; Zernicke, Ronald F.; Bedi, Asheesh; Goulet, Grant C.

    2014-01-01

    Background: Femoroacetabular impingement is a debilitating hip condition commonly affecting athletes playing American football. The condition is associated with reduced hip range of motion; however, little is known about the range-of-motion demands of football athletes. This knowledge is critical to effective management of this condition. Purpose: To (1) develop a normative database of game-like hip and knee kinematics used by football athletes and (2) analyze kinematic data by playing position. The hypothesis was that kinematics would be similar between running backs and defensive backs and between wide receivers and quarterbacks, and that linemen would perform the activities with the most erect lower limb posture. Study Design: Descriptive laboratory study. Methods: Forty National Collegiate Athletic Association (NCAA) football athletes, representing 5 playing positions (quarterback, defensive back, running back, wide receiver, offensive lineman), executed game-like maneuvers while lower body kinematics were recorded via optical motion capture. Passive hip range of motion at 90° of hip flexion was assessed using a goniometer. Passive range of motion, athlete physical dimensions, hip function, and hip and knee rotations were submitted to 1-way analysis of variance to test for differences between playing positions. Correlations between maximal hip and knee kinematics and maximal hip kinematics and passive range of motion were also computed. Results: Hip and knee kinematics were similar across positions. Significant differences arose with linemen, who used lower maximal knee flexion (mean ± SD, 45.04° ± 7.27°) compared with running backs (61.20° ± 6.07°; P < .001) and wide receivers (54.67° ± 6.97°; P = .048) during the cut. No significant differences were found among positions for hip passive range of motion (overall means: 102° ± 15° [flexion]; 25° ± 9° [internal rotation]; 25° ± 8° [external rotation]). Several maximal hip measures were found

  3. Methods for dynamic characterization of the major muscles activating the lower limb joints in cycling motion

    Directory of Open Access Journals (Sweden)

    Navit Roth

    2014-04-01

    Full Text Available The functional activation, through electrical stimulation, of the lower limb consisting of several deficient muscles requires well-patterned and coordinated activation of these muscles. This study presents a method for characterizing the parameters of the major muscle groups controlling the ankle and knee joints in cycling motion, the latter having particular significance in the rehabilitation of locomotion. To lower mechanical indeterminacy in the joints the system is reduced by grouping the muscles acting in synergism. The joint torques were calculated by inverse dynamics methods from cycling motion data, including kinematics and foot/pedal reaction loads (forces, moments. The mechanical indeterminacy was resolved by applying optimization criteria and the individual muscle torques were parceled-out from the joint torques. System identification of the individual muscles, part of which being bi-articular, in this non-isometric condition was performed from the relationship between the evaluated force and the measured EMG of each the muscles, using both first and second order linear transfer functions. Feasibility of the presented method was demonstrated through the computation of the coefficients of the muscles involved and validating the results on the experimental data obtained from one subject.

  4. Methods for dynamic characterization of the major muscles activating the lower limb joints in cycling motion

    Directory of Open Access Journals (Sweden)

    Navit Roth

    2014-09-01

    Full Text Available The functional activation, through electrical stimulation, of the lower limb consisting of several deficient muscles requires well-patterned and coordinated activation of these muscles. This study presents a method for characterizing the parameters of the major muscle groups controlling the ankle and knee joints in cycling motion, the latter having particular significance in the rehabilitation of locomotion. To lower mechanical indeterminacy in the joints the system is reduced by grouping the muscles acting in synergism. The joint torques were calculated by inverse dynamics methods from cycling motion data, including kinematics and foot/pedal reaction loads (forces, moments. The mechanical indeterminacy was resolved by applying optimization criteria and the individual muscle torques were parceled-out from the joint torques. System identification of the individual muscles, part of which being bi-articular, in this non-isometric condition was performed from the relationship between the evaluated force and the measured EMG of each the muscles, using both first and second order linear transfer functions. Feasibility of the presented method was demonstrated through the computation of the coefficients of the muscles involved and validating the results on the experimental data obtained from one subject.

  5. In vivo prompt gamma neutron activation analysis for the screening of boron-10 distribution in a rabbit knee: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, X; Yanch, J [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, MA (United States); Clackdoyle, R [Laboratoire Hubert Curien, Mixed Research Unit (UMR) 5516, CNRS and Universite Jean Monnet, Saint Etienne (France); Shortkroff, S [Department of Orthopedic Surgery, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA (United States)

    2008-05-21

    Boron neutron capture synovectomy (BNCS) is under development as a potential treatment modality for rheumatoid arthritis (RA). RA is characterized by the inflammation of the synovium (the membrane lining articular joints), which leads to pain and a restricted range of motion. BNCS is a two-part procedure involving the injection of a boronated compound directly into the diseased joint followed by irradiation with a low-energy neutron beam. The neutron capture reactions taking place in the synovium deliver a local, high-linear energy transfer (LET) dose aimed at destroying the inflamed synovial membrane. For successful treatment via BNCS, a boron-labeled compound exhibiting both high synovial uptake and long retention time is necessary. Currently, the in vivo uptake behavior of potentially useful boronated compounds is evaluated in the knee joints of rabbits in which arthritis has been induced. This strategy involves the sacrifice and dissection of a large number of animals. An in vivo {sup 10}B screening approach is therefore under investigation with the goal of significantly reducing the number of animals needed for compound evaluation via dissection studies. The 'in vivo prompt gamma neutron activation analysis' (IVPGNAA) approach uses a narrow neutron beam to irradiate the knee from several angular positions following the intra-articular injection of a boronated compound whose uptake characteristics are unknown. A high-purity germanium detector collects the 478 keV gamma photons produced by the {sup 10}B capture reactions. The {sup 10}B distribution in the knee is then reconstructed by solving a system of simultaneous equations using a weighted least squares algorithm. To study the practical feasibility of IVPGNAA, simulation data were generated with the Monte Carlo N-particle transport code. The boron-containing region of a rabbit knee was partitioned into 8 compartments, and the {sup 10}B prompt gamma signals were tallied from 16 angular positions

  6. In vivo prompt gamma neutron activation analysis for the screening of boron-10 distribution in a rabbit knee: a simulation study

    Science.gov (United States)

    Zhu, X.; Clackdoyle, R.; Shortkroff, S.; Yanch, J.

    2008-05-01

    Boron neutron capture synovectomy (BNCS) is under development as a potential treatment modality for rheumatoid arthritis (RA). RA is characterized by the inflammation of the synovium (the membrane lining articular joints), which leads to pain and a restricted range of motion. BNCS is a two-part procedure involving the injection of a boronated compound directly into the diseased joint followed by irradiation with a low-energy neutron beam. The neutron capture reactions taking place in the synovium deliver a local, high-linear energy transfer (LET) dose aimed at destroying the inflamed synovial membrane. For successful treatment via BNCS, a boron-labeled compound exhibiting both high synovial uptake and long retention time is necessary. Currently, the in vivo uptake behavior of potentially useful boronated compounds is evaluated in the knee joints of rabbits in which arthritis has been induced. This strategy involves the sacrifice and dissection of a large number of animals. An in vivo 10B screening approach is therefore under investigation with the goal of significantly reducing the number of animals needed for compound evaluation via dissection studies. The 'in vivo prompt gamma neutron activation analysis' (IVPGNAA) approach uses a narrow neutron beam to irradiate the knee from several angular positions following the intra-articular injection of a boronated compound whose uptake characteristics are unknown. A high-purity germanium detector collects the 478 keV gamma photons produced by the 10B capture reactions. The 10B distribution in the knee is then reconstructed by solving a system of simultaneous equations using a weighted least squares algorithm. To study the practical feasibility of IVPGNAA, simulation data were generated with the Monte Carlo N-particle transport code. The boron-containing region of a rabbit knee was partitioned into 8 compartments, and the 10B prompt gamma signals were tallied from 16 angular positions. Results demonstrate that for this

  7. Effect of ACL graft material on anterior knee force during simulated in vivo ovine motion applied to the porcine knee: An in vitro examination of force during 2000 cycles.

    Science.gov (United States)

    Boguszewski, Daniel V; Wagner, Christopher T; Butler, David L; Shearn, Jason T

    2015-12-01

    This study determined how anterior cruciate ligament (ACL) reconstruction affected the magnitude and temporal patterns of anterior knee force and internal knee moment during 2000 cycles of simulated gait. Porcine knees were tested using a six degree-of-freedom robot, examining three porcine allograft materials compared with the native ACL. Reconstructions were performed using: (1) bone-patellar tendon-bone allograft (BPTB), (2) reconstructive porcine tissue matrix (RTM), or (3) an RTM-polymer hybrid construct (Hybrid). Forces and moments were measured over the entire gait cycle and contrasted at heel strike, mid stance, toe off, and peak flexion. The Hybrid construct performed the best, as magnitude and temporal changes in both anterior knee force and internal knee moment were not different from the native ACL knee. Conversely, the RTM knees showed greater loss in anterior knee force during 2000 cycles than the native ACL knee at heel strike and toe off, with an average force loss of 46%. BPTB knees performed the least favorably, with significant loss in anterior knee force at all key points and an average force loss of 61%. This is clinically relevant, as increases in post-operative knee laxity are believed to play a role in graft failure and early onset osteoarthritis. PMID:26134453

  8. Total knee arthroplasty for knee varus deformity:follow-up evaluation of femorotibial angle and range of motion%全膝关节置换修复膝内翻畸形:胫股角及膝关节活动度随访评价

    Institute of Scientific and Technical Information of China (English)

    李广伟; 王红军; 孙晓智; 陈林斌; 高宇亮; 白忠旭; 程新胜

    2015-01-01

      结果与结论:所有患者均获得随访,随访时间为12-96个月,随访方式为门诊复查随访。胫股角由置换前平均内翻17.69°(5°-30°)纠正至置换后的5.66°(2°-8°),膝关节活动度由置换前的74.29°(60°-95°)提高到置换后119.46°(105°-130°);HSS评分由置换前的26.60分(14-42分)提高到置换后89.03分(82-95分),优28膝,良7膝;WOMAC评分由42.83分(28-54分)提高到置换后90.17分(85-95分)。结果经统计学分析提示,所有病例置换后胫股角、膝关节活动度、HSS及WOMAC评分均较置换前显著改善(P OBJECTIVE:To observe the femorotibial angle and range of knee joint motion of adults patients with knee varus deformity during 1-year fol ow-up after total knee arthroplasty. METHODS:A total of 31 patients (35 knees) with knee varus deformity were treated with posterior stabilized prosthesis replacement from June 2006 to June 2013. Using patel ar medial approach, the correct osteotomy and selective soft tissue release were performed to restore normal knee alignment and soft tissue balance. Posterior stabilized prosthesis in total knee arthroplasty was applied to achieve knee stability. Postoperative targeted rehabilitation training was also fol owed. The femorotibial angle was measured before and after surgery. The range of knee joint motion was determined during postoperative fol ow-up. Patients were evaluated with the Hospital for Special Surgery (HSS) score and the Western Ontario and McMaster Universities (WOMAC) Osteoarthritis Index. RESULTS AND CONCLUSION:Al patients were fol owed up for 12-96 months through out-patient clinic. The femorotibial angle was corrected from preoperative varus 17.69° (5°-30°) to postoperative 5.66° (2°-8°);the range of knee joint motion was improved from preoperative 74.29° (60°-95°) to 119.46° (105°-130°);the HSS score increased from preoperative 26.60 points (14-42 points) to postoperative 89.03 points (82-95 points

  9. After total knee arthroplasty, many people are not active enough to maintain their health and fitness : an observational study

    NARCIS (Netherlands)

    Groen, Jan-Willem; Stevens, Martin; Kersten, Roel F. M. R.; Reininga, Inge H. F.; van den Akker-Scheek, Inge

    2012-01-01

    Questions: What proportion of people after total knee arthroplasty adheres to the physical activity regimen recommended for maintenance of health (moderate intensity physical activity for at least 30 min on 5 days/week)? What proportion adheres to the activity regimen recommended to improve fitness

  10. Human-robot interaction: kinematics and muscle activity inside a powered compliant knee exoskeleton.

    Science.gov (United States)

    Knaepen, Kristel; Beyl, Pieter; Duerinck, Saartje; Hagman, Friso; Lefeber, Dirk; Meeusen, Romain

    2014-11-01

    Until today it is not entirely clear how humans interact with automated gait rehabilitation devices and how we can, based on that interaction, maximize the effectiveness of these exoskeletons. The goal of this study was to gain knowledge on the human-robot interaction, in terms of kinematics and muscle activity, between a healthy human motor system and a powered knee exoskeleton (i.e., KNEXO). Therefore, temporal and spatial gait parameters, human joint kinematics, exoskeleton kinetics and muscle activity during four different walking trials in 10 healthy male subjects were studied. Healthy subjects can walk with KNEXO in patient-in-charge mode with some slight constraints in kinematics and muscle activity primarily due to inertia of the device. Yet, during robot-in-charge walking the muscular constraints are reversed by adding positive power to the leg swing, compensating in part this inertia. Next to that, KNEXO accurately records and replays the right knee kinematics meaning that subject-specific trajectories can be implemented as a target trajectory during assisted walking. No significant differences in the human response to the interaction with KNEXO in low and high compliant assistance could be pointed out. This is in contradiction with our hypothesis that muscle activity would decrease with increasing assistance. It seems that the differences between the parameter settings of low and high compliant control might not be sufficient to observe clear effects in healthy subjects. Moreover, we should take into account that KNEXO is a unilateral, 1 degree-of-freedom device.

  11. Companion classroom activities for "stop faking it!" force and motion

    CERN Document Server

    Robertson, William C

    2011-01-01

    Never has it been so easy for educators to learn to teach physical science with confidence. Award-winning author Bill Robertson launched his bestselling Stop Faking It! series in 2002 with Force and Motion--offering elementary and middle school teachers a jargon-free way to learn the background for teaching physical science with confidence. Combining easy-to-understand if irreverent explanations and quirky diagrams, Stop Faking It! Force and Motion helped thousands of teachers, parents, and homeschoolers conquer topics from Newton s laws to the physics of space travel. Now Companion Classroom Activities for Stop Faking It! Force and Motion proves an ideal supplement to the original book or a valuable resource of its own. The hands-on activities and highly readable explanations allow students to first investigate concepts, then discuss learned concepts, and finally apply the concepts to everyday situations. Robertson's wit and humor are sure to keep students and teachers entertained while they tackle topics ...

  12. Knee Power Is an Important Parameter in Understanding Medial Knee Joint Load in Knee Osteoarthritis

    OpenAIRE

    Calder, Kristina M; Acker, Stacey M; Arora, Neha; Beattie, Karen A.; Jack P. Callaghan; Jonathan D. Adachi; Maly, Monica R.

    2014-01-01

    Objective To determine the extent to which knee extensor strength and power explain variance in knee adduction moment (KAM) peak and impulse in clinical knee osteoarthritis (OA). Methods Fifty-three adults (mean ± SD age 61.6 ± 6.3 years, 11 men) with clinical knee OA participated. The KAM waveform was calculated from motion and force data and ensemble averaged from 5 walking trials. The KAM peak was normalized to body mass (Nm/kg). The mean KAM impulse reflected the mean total medial knee lo...

  13. 全膝关节置换治疗成人膝外翻畸形:胫股角及膝关节活动度变化%Total knee arthroplasty for knee valgus deformity in the adults: Changes of tibiofemoral angle and range of motion of knee joint

    Institute of Scientific and Technical Information of China (English)

    李广伟

    2012-01-01

    BACKGROUND: Application of total knee arthroplasty (TKA) for knee valgus deformity can be difficult technically in many aspects and exist a lot of controversy.OBJECTIVE: To investigate the clinical efficiency and surgical methods of TKA for knee valgus deformity in the adults.METHODS: Totally 15 knees from 12 patients underwent patellar lateral approach for proper osteotomy and selective lysis of the soft tissue to regain normal biomechanics and soft tissue balance of knee were selected. Posterior stabilized prosthesis was used for TKA to obtain the stability of the knee. After the surgery, rehabilitation therapy pertinently was adopted. Before and after the surgery, tibiofemoral angle was measured. Range of motion (ROM) was examined and HSS score was evaluated.RESULTS AND CONCLUSION: All patients were followed up over 6 months. Tibiofemoral angle decreased from 21.47° preoperatively to 5.47° postoperatively (P < 0.01). The ROM increased from 81.33° preoperatively to 121.07° postoperatively (P < 0.01). HSS score improved from 25.47 preoperatively to 89.87 postoperatively (P < 0.01). After replacement, 1 case affected more joint effusion, 2 cases affected knee instability. There was no dislocation or subluxation of the patella. Force line of lower limb returned to normal. TKA can effectively correct the knee valgus deformity, and can significantly improve the function of the knee.%背景:膝外翻畸形施行人工全膝关节置换难度很大,涉及面多,争议亦颇多.目的:观察全膝关节置换治疗成人膝外翻畸形的手术方法和临床效果.方法:对12例15膝采用髌骨内侧入路,正确截骨,选择性的软组织松解,恢复膝关节正常的力线和软组织平衡,采用后稳定型假体进行全膝关节置换,获得膝关节的稳定,置换后采取针对性的康复训练,置换前后测量胫股角,并置换后定期随访检查膝关节活动度并进行HSS评分.结果与结论:所有患者获得随访均>6

  14. Knee hemarthrosis after arthroscopic surgery in an athlete with low factor XIII activity

    Directory of Open Access Journals (Sweden)

    Tsujii Akira

    2012-10-01

    Full Text Available Abstract We report a thirteen-year-old tennis player with knee hemarthrosis caused by low factor XIII activity. She visited our hospital because of medial peripatellar pain for two years. Although there was no abnormal sign in X-ray or MRI, diagnostic arthroscopy was performed. It revealed some cartilage debris, medial plica and complete septum of suprapatellar plica. Removing the debris by washing out and resecting the medial plica, she could return to play tennis without perioperative symptom. Two months after the first operation, her knee got swelling without any apparent cause. Since 20 ml blood was aspirated twice and MRI revealed suprapatellar mass, we performed arthroscopy again. Suprapatellar mass was old blood clot covered with complete suprapatellar plica. Resection of suprapatellar plica and washing out blood clot were performed, and severe postoperative hemarthrosis was progressively occurred. As factor XIII level was 54% preoperatively, we diagnosed that this condition was caused by low activity level of the factor and administered factor XIII concentrates. The level got improved to 129% and then hemarthrosis gradually relieved. She had no signs of recurrence. We should keep in mind of low factor XIII activity case in case of unexplained postoperative hemarthrosis after arthroscopy because consumption of the factor might promote this condition.

  15. An acute bout of self-myofascial release increases range of motion without a subsequent decrease in muscle activation or force.

    Science.gov (United States)

    MacDonald, Graham Z; Penney, Michael D H; Mullaley, Michelle E; Cuconato, Amanda L; Drake, Corey D J; Behm, David G; Button, Duane C

    2013-03-01

    Foam rolling is thought to improve muscular function, performance, overuse, and joint range of motion (ROM); however, there is no empirical evidence demonstrating this. Thus, the objective of the study was to determine the effect of self-myofascial release (SMR) via foam roller application on knee extensor force and activation and knee joint ROM. Eleven healthy male (height 178.9 ± 3.5 cm, mass 86.3 ± 7.4 kg, age 22.3 ± 3.8 years) subjects who were physically active participated. Subjects' quadriceps maximum voluntary contraction force, evoked force and activation, and knee joint ROM were measured before, 2 minutes, and 10 minutes after 2 conditions: (a) 2, 1-minute trials of SMR of the quadriceps via a foam roller and (b) no SMR (Control). A 2-way analysis of variance (condition × time) with repeated measures was performed on all dependent variables recorded in the precondition and postcondition tests. There were no significant differences between conditions for any of the neuromuscular dependent variables. However, after foam rolling, subjects' ROM significantly (p < 0.001) increased by 10° and 8° at 2 and 10 minutes, respectively. There was a significant (p < 0.01) negative correlation between subjects' force and ROM before foam rolling, which no longer existed after foam rolling. In conclusion, an acute bout of SMR of the quadriceps was an effective treatment to acutely enhance knee joint ROM without a concomitant deficit in muscle performance.

  16. Activity, Sleep and Cognition After Fast-Track Hip or Knee Arthroplasty

    DEFF Research Database (Denmark)

    Krenk, Lene; Jennum, Poul; Kehlet, Henrik

    2013-01-01

    postoperatively cognitive decline and increased pain returned to preoperative levels by postoperative day (POD) 5-9. Despite the small sample size the study illustrated that post-discharge activity is decreased and daytime sleep is increased after fast-track THA/TKA, while cognition and pain return......Optimized perioperative care after total hip and knee arthroplasty (THA/TKA) has decreased length of stay (LOS) but data on activity, sleep and cognition after discharge are limited. We included 20 patients ≥60years undergoing THA/TKA, monitoring them for 3days preoperatively and 9days...... postoperatively with actigraphs for sleep and activity assessment. Pain scores were recorded daily. Cognition was evaluated by 2 cognitive tests. Results showed a mean age was 70.5years and mean LOS was 2.6days. Actigraphs showed increased daytime sleep and decreased motor activity postoperatively. Early...

  17. The Effects of Knee Joint and Hip Abduction Angles on the Activation of Cervical and Abdominal Muscles during Bridging Exercises.

    Science.gov (United States)

    Lee, Su-Kyoung; Park, Du-Jin

    2013-07-01

    [Purpose] The purpose of this study was to examine the effects of the flexion angle of the knee joint and the abduction angle of the hip joint on the activation of the cervical region and abdominal muscles. [Subjects] A total of 42 subjects were enrolled 9 males and 33 females. [Methods] The bridging exercise in this study was one form of exercise with a knee joint flexion angle of 90°. Based on this, a bridging exercise was conducted at the postures of abduction of the lower extremities at 0, 5, 10, and 15°. [Result] The changes in the knee joint angle and the hip abduction angle exhibited statistically significant effects on the cervical erector spinae, adductor magnus, and gluteus medius muscles. The abduction angles did not result in statistically significant effects on the upper trapezium, erector spinae, external oblique, and rectus abdominis muscles. However, in relation to the knee joint angles, during the bridging exercise, statistically significant results were exhibited. [Conclusion] When patients with both cervical and back pain do a bridging exercise, widening the knee joint angle would reduce cervical and shoulder muscle activity through minimal levels of abduction, permitting trunk muscle strengthening with reduced cervical muscle activity. This method would be helpful for strengthening trunk muscles in a selective manner. PMID:24259870

  18. Prevalent knee pain and sport

    DEFF Research Database (Denmark)

    Hahn, Thomas; Foldspang, Anders

    1998-01-01

    STUDY OBJECTIVE: To estimate the prevalence of knee pain in active athletes and to investigate potential associations to type, amount and duration of sports participation. MEASUREMENTS: 339 athletes gave information about occupation, sports activity and different features of knee pain, based...... on a self-filled questionnaire. MAIN RESULTS: The prevalence of knee pain within the preceding 12 months, constant or recurrent knee pain, absence from sport and absence from work due to knee pain, was 54%, 34%, 19% and 4%, respectively. Knee pain was positively associated with years of jogging...... and with weekly hours of participation in competitive gymnastics but negatively with weekly hours of tennis. Constant or recurrent knee pain was positively associated with years of swimming. Absence from sport due to knee pain was positively associated with weekly hours of soccer participation. CONCLUSIONS: Knee...

  19. H.264 MOTION ESTIMATION ALGORITHM BASED ON VIDEO SEQUENCES ACTIVITY

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Motion estimation is an important part of H.264/AVC encoding progress, with high computational complexity. Therefore, it is quite necessary to find a fast motion estimation algorithm for real-time applications. The algorithm proposed in this letter adjudges the macroblocks activity degree first; then classifies different video sequences, and applies different search strategies according to the result. Experiments show that this method obtains almost the same video quality with the Full Search (FS) algorithm but with reduced more than 95% computation cost.

  20. Statistics of Superluminal Motion in Active Galactic Nuclei

    Institute of Scientific and Technical Information of China (English)

    Yong-Wei Zhang; Jun-Hui Fan

    2008-01-01

    We have collected an up-to-date sample of 123 superluminal sources (84 quasars, 27 BL Lac objects and 12 galaxies) and calculated the apparent velocities (βapp) for 224 components in the sources with the A-CDM model. We checked the relationships between their proper motions, redshifts,βapp and 5 GHz flux densities. Our analysis shows that the radio emission is strongly boosted by the Doppler effect. The superluminal motion and the relativistic beaming boosting effect are, to some extent, the same in active galactic nuclei.

  1. The contribution of activated peripheral kappa opioid receptors (kORs) in the inflamed knee joint to anti-nociception.

    Science.gov (United States)

    Moon, Sun Wook; Park, Eui Ho; Suh, Hye Rim; Ko, Duk Hwan; Kim, Yang In; Han, Hee Chul

    2016-10-01

    The systemic administration of opioids can be used for their strong analgesic effect. However, extensive activation of opioid receptors (ORs) beyond the targeted tissue can cause dysphoria, pruritus, and constipation. Therefore, selective activation of peripheral ORs present in the afferent fibers of the targeted tissue can be considered a superior strategy in opioid analgesia to avoid potential adverse effects. The purpose of this study was to clarify the role of peripheral kappa opioid receptors (kORs) in arthritic pain for the possible use of peripheral ORs as a target in anti-nociceptive therapy. We administered U50488 or nor-BNI/DIPPA, a selective agonist or antagonist of kOR, respectively into arthritic rat knee joints induced using 1% carrageenan. After the injection of U50488 or U50488 with nor-BNI or DIPPA into the inflamed knee joint, we evaluated nociceptive behavior as indicated by reduced weight-bearing on the ipsilateral limbs of the rat and recorded the activity of mechanosensitive afferents (MSA). In the inflamed knee joint, the intra-articular application of 1μM, 10nM, or 0.1nM U50488 resulted in a significant reduction in nociceptive behavior. In addition, 1μM and 10nM U50488 decreased MSA activity. However, in a non-inflamed knee joint, 1μM U50488 had no effect on MSA activity. Additionally, intra-articular pretreatment with 20μM nor-BNI or 10μM DIPPA significantly blocked the inhibitory effects of 1μM U50488 on nociceptive behavior and MSA activity in the inflamed knee joint. These results implicate that peripheral kORs can contribute to anti-nociceptive processing in an inflamed knee joint. PMID:27378583

  2. Thompson′s quadricepsplasty for stiff knee

    Directory of Open Access Journals (Sweden)

    Kundu Z

    2007-01-01

    Full Text Available Background : Stiffness of the knee after trauma and/or surgery for femoral fractures is one of the most common complications and is difficult to treat. Stiffness in extension is more common and can be reduced by vigorous physiotherapy. If it does not improve then quadricepsplasty is indicated. The present study was undertaken to evaluate the results of Thompsons quadricepsplasty. Materials and Methods : 22 male patients (age range 20-45 years with posttraumatic knee stiffness following distal femoral fractures underwent Thompson′s quadricepsplasty where knee flexion range was less than 45°. The index injury in these patients was treated with plaster cast (n=5, plates (n=3, intramedullary nailing (n=3 and external fixator for open fractures (n=9. Thompson′s quadricepsplasty was performed in all the patients using anterior approach, with incision extending from upper thigh to tibial tubercle. Release of rectus femoris from underlying vastus intermedius and release of intraarticular adhesions were performed. After surgery the patients needed parentral analgesia for three days and then oral analgesics for three weeks. Active assisted knee mobilization exercises were started on the first post-operative day. Continous passive motion machine was used from the same day. Supervised physiotherapy was continued in hospital for six weeks followed by intensive knee flexion and extension exercise including cycling at home for atleast another six months. Results : Out of 22 patients, 20 had excellent to good results and two patients had poor results using criteria devised by Judet. One poor result was due to peroperative fracture of patella which was then internally fixed and hence the flexion of knee could not be started immediately. There was peroperative avulsion of tibial tuberosity in another patient who finally gained less than 50° knee flexion and hence a poor result. Conclusion : Thompsons quadricepsplasty followed by a strict and rigourous

  3. Age-related changes in kinematics of the knee joint during deep squat.

    Science.gov (United States)

    Fukagawa, Shingo; Leardini, Alberto; Callewaert, Barbara; Wong, Pius D; Labey, Luc; Desloovere, Kaat; Matsuda, Shuichi; Bellemans, Johan

    2012-06-01

    Researchers frequently use the deep knee squat as a motor task in order to evaluate the kinematic performance after total knee arthroplasty. Many authors reported about the kinematics of a normal squatting motion, however, little is known on what the influence of aging is. Twenty-two healthy volunteers in various age groups (range 21-75 years) performed a deep knee squat activity while undergoing motion analysis using an optical tracking system. The influence of aging was evaluated with respect to kinematics of the trunk, hip, knee and ankle joints. Older subjects required significantly more time to perform a deep squat, especially during the descending phase. They also had more knee abduction and delayed peak knee flexion. Older subjects were slower in descend than ascend during the squat. Although older subjects had a trend towards less maximal flexion and less internal rotation of the knee compared to younger subjects, this difference was not significant. Older subjects also showed a trend towards more forward leaning of the trunk, resulting in increased hip flexion and anterior thoracic tilt. This study confirmed that some aspects of squat kinematics vary significantly with age, and that the basic methodology employed here can successfully detect these age-related trends. Older subjects had more abduction of the knee joint, and this may indicate the load distribution of the medial and lateral condyles could be different amongst ages. Age-matched control data are therefore required whenever the performance of an implant is evaluated during a deep knee squat.

  4. Prognosis of limitations in activities in osteoarthritis of the hip or knee: a 3-year cohort study.

    NARCIS (Netherlands)

    Dijk, G.M. van; Veenhof, C.; Spreeuwenberg, P.; Coene, N.; Burger, B.J.; Schaardenburg, D.J. van; Ende, C.H.M. van den; Lankhorst, G.J.; Dekker, J.

    2010-01-01

    OBJECTIVE: To describe the course of limitations in activities in elderly patients with osteoarthritis (OA) of the hip or knee over a follow-up period of 3 years, and to identify prognostic factors of the course of limitations in activities, focusing on body functions, comorbidity, and cognitive fun

  5. Development and preliminary testing of a computerized Animated Activity Questionnaire (AAQ) in patients with hip and knee osteoarthritis

    DEFF Research Database (Denmark)

    Peter, Wf; Loos, M; de Vet, Hcw;

    2015-01-01

    Objective To develop an Animated Activity Questionnaire (AAQ), based on video animations, for assessing activity limitations in patients with hip/knee osteoarthritis (OA), which combines the advantages of self-reported questionnaires and performance-based tests, without many of their limitations,...

  6. Differential brain activity states during the perception and nonperception of illusory motion as revealed by magnetoencephalography

    OpenAIRE

    Crowe, David A.; Leuthold, Arthur C.; Georgopoulos, Apostolos P.

    2010-01-01

    We studied visual perception using an annular random-dot motion stimulus called the racetrack. We recorded neural activity using magnetoencephalography while subjects viewed variants of this stimulus that contained no inherent motion or various degrees of embedded motion. Subjects reported seeing rotary motion during viewing of all stimuli. We found that, in the absence of any motion signals, patterns of brain activity differed between states of motion perception and nonperception. Furthermor...

  7. Course of limitations in activities in osteoarthritis of the hip or knee: the influence of physical impairments, comorbidity and cognitive dysfunction.

    NARCIS (Netherlands)

    Dijk, G.M. van; Veenhof, C.; Dekker, J.

    2008-01-01

    Objectives: to describe the course of limitations in activities in elderly patients with osteoarthritis of the hip or knee, and (ii) to identify age related factors that predict the course of limitations in activities in patients with osteoarthritis of hip or knee. Methods: A longitudinal cohort stu

  8. Fuzzy Modelling of Knee Joint with Genetic Optimization

    Directory of Open Access Journals (Sweden)

    B. S. K. K. Ibrahim

    2011-01-01

    Full Text Available Modelling of joint properties of lower limbs in people with spinal cord injury is significantly challenging for researchers due to the complexity of the system. The objective of this study is to develop a knee joint model capable of relating electrical parameters to dynamic joint torque as well as knee angle for functional electrical stimulation application. The joint model consists of a segmental dynamic, time-invariant passive properties and uncertain time-variant active properties. The knee joint model structure comprising optimised equations of motion and fuzzy models to represent the passive viscoelasticity and active muscle properties is formulated. The model thus formulated is optimised using genetic optimization, and validated against experimental data. The developed model can be used for simulation of joint movements as well as for control development. The results show that the model developed gives an accurate dynamic characterisation of the knee joint.

  9. Treatment and Rehabilitation of Knee Joints Straight Stiffness After Burns.

    Science.gov (United States)

    Tang, Jinshu; Xu, Minghuo; Wu, Wenwen; Hu, Yuan; Shi, Xiuxiu; Hou, Shuxun

    2015-12-01

    The knee release surgery and postoperative rehabilitation of patients after burns and knee straight stiffness were investigated. Eleven patients were treated for 16 side burns and knee stiffness who consisted of nine males and two females, aged 19 to 54 years (mean = 33.2). The duration of the patients' knee stiffness ranged from 8 to 26 months, with an average of 12.6 months. Their preoperative flexion ranged from 5° to 50°, with an average of 26.2°. Their preoperative Hospital for Special Surgery (HSS) knee scores ranged from 46 to 72 points, with an average of 55.8 points. All stiff knees were treated with release surgery, along with total release of intra-articular adhesion and excision of vastus intermedius. After the arthrolysis of the stiff knee joint, the tight skin was completely loose in the adhesions. The soft tissue contracture was not grafted, but the shade fascia was freed to increase skin ductility. All knee joints were released to more than 90° of flexion in the operation, and reversed fascia flaps were used to suture the loss of the deep fascia at the position of flexion of 90°. After the operation, the knee joint was fixed in flexion for 72 h while being actively cared for by early rehabilitation. Subsequently, the patient's skin coverage, joint motion, and joint function recovery were observed. Based on the follow-up of the patients for the following 16 to 36 months (mean = 25.7), the knee flexion of the patients ranged from 110° to 135°, with an average of 122.2° and 96° increase (P fascia, thus avoiding the need to undergo skin grafting. Short-term fixation of the joints after surgery and active flexion rehabilitation may also be the key to improve skin ductility and joint function of the patients. PMID:27011516

  10. Cyclops lesion of the knee.

    OpenAIRE

    Nikolic, O; Vanhoenacker, F. M.; Petrovic, K.; Vandenberk, P

    2012-01-01

    A 38-year-old patient had undergone Anterior Cruciate Ligament (ACL) reconstruction after severe ACL injury in the past. He presented with decreased range of motion, anterior knee pain and inability to fully extend the knee. Magnetic Resonance Imaging (MRI) was performed to assess the cause of extension loss.

  11. 膝关节运动康复器与伸筋汤熏洗联合治疗股骨髁部骨折术后膝关节僵直的疗效观察%To Observe the Motion of Knee Joint Rehabilitation and Extensor Tendon Soup Fumigation Combined With Treatment of Femoral Condylar Fractures of Knee Ankylosis

    Institute of Scientific and Technical Information of China (English)

    赵明

    2015-01-01

    目的:探究股骨髁部骨折术后膝关节僵直采用膝关节运动康复器联合伸筋汤熏洗治疗的临床疗效。方法选取股骨髁部骨折术后膝关节僵直患者62例,随机分为对照组和观察组各31例,对照组采用膝关节运动康复器治疗,在此基础上,观察组采用伸筋汤熏洗治疗,比较其治疗效果。结果观察组患者治疗优良率高于对照组(P<0.05)。结论采用膝关节运动康复器与伸筋汤熏洗联合治疗股骨髁部骨折术后膝关节僵直,临床疗效显著。%ObjectiveTo explore clinical efficacy of femoral condylar fracture with postoperative stiffness of knee joint motion of knee joint rehabilitation combined with extensor tendon soup fumigation treatment.Methods 62 cases of knee joint stiffness in patients with femoral condylar fracture after operation, were randomly divided into control group and observation group with 31 cases in each group, the control group with rehabilitation treatment of knee joint motion, on the basis of this, the observation group with extensor tendon soup fumigation treatment. ResultsThe patients in the observation group was higher than the control group(P<0.05).Conclusion The knee joint rehabilitation and extension tendon soup fumigation treatment of femoral condylar fracture postoperative knee stiffness, clinical curative effect.

  12. Muscle activation and knee biomechanics during squatting and lunging after lower extremity fatigue in healthy young women.

    Science.gov (United States)

    Longpré, Heather S; Acker, Stacey M; Maly, Monica R

    2015-02-01

    Muscle activations and knee joint loads were compared during squatting and lunging before and after lower extremity neuromuscular fatigue. Electromyographic activations of the rectus femoris, vastus lateralis and biceps femoris, and the external knee adduction and flexion moments were collected on 25 healthy women (mean age 23.5 years, BMI of 23.7 kg/m(2)) during squatting and lunging. Participants were fatigued through sets of 50 isotonic knee extensions and flexions, with resistance set at 50% of the peak torque achieved during a maximum voluntary isometric contraction. Fatigue was defined as a decrease in peak isometric knee extension or flexion torque ≥25% from baseline. Co-activation indices were calculated between rectus femoris and biceps femoris; and between vastus lateralis and biceps femoris. Fatigue decreased peak isometric extension and flexion torques (pknee adduction and flexion moments during lunging (p<0.05). Quadriceps activations were greater during lunging than squatting (p<0.05). Thus, fatigue altered the recruitment strategy of the quadriceps during squatting and lunging. Lunging challenges quadriceps activation more than squatting in healthy, young women.

  13. The Effects of Knee Joint and Hip Abduction Angles on the Activation of Cervical and Abdominal Muscles during Bridging Exercises

    OpenAIRE

    Lee, Su-Kyoung; Park, Du-Jin

    2013-01-01

    [Purpose] The purpose of this study was to examine the effects of the flexion angle of the knee joint and the abduction angle of the hip joint on the activation of the cervical region and abdominal muscles. [Subjects] A total of 42 subjects were enrolled 9 males and 33 females. [Methods] The bridging exercise in this study was one form of exercise with a knee joint flexion angle of 90°. Based on this, a bridging exercise was conducted at the postures of abduction of the lower extremities at 0...

  14. After total knee arthroplasty, many people are not active enough to maintain their health and fitness: an observational study

    OpenAIRE

    Groen, Jan-Willem; Stevens, Martin; Kersten, Roel F. M. R.; Reininga, Inge H. F.; van den Akker-Scheek, Inge

    2012-01-01

    Questions: What proportion of people after total knee arthroplasty adheres to the physical activity regimen recommended for maintenance of health (moderate intensity physical activity for at least 30 min on 5 days/week)? What proportion adheres to the activity regimen recommended to improve fitness (vigorous intensity physical activity for at least 20 min on 3 days/week)? What factors are associated with adherence to these recommendations? Design: An observational study. Participants: 830 adu...

  15. Diabetes that impacts on routine activities predicts slower recovery after total knee arthroplasty: an observational study

    Directory of Open Access Journals (Sweden)

    Nurudeen Amusat

    2014-12-01

    Full Text Available Question: In the 6 months after total knee arthroplasty (TKA, what is the pattern of pain resolution and functional recovery in people without diabetes, with diabetes that does not impact on routine activities, and with diabetes that does impact on routine activities? Is diabetes that impacts on routine activities an independent predictor of slower resolution of pain and functional recovery after TKA? Design: Community-based prospective observational study. Participants: A consecutive cohort of 405 people undergoing primary TKA, of whom 60 (15% had diabetes. Participants with diabetes were also asked preoperatively whether diabetes impacted on their routine activities. Participants were categorised into three groups: no diabetes (n = 345, diabetes with no impact on activities (n = 41, and diabetes that impacted activities (n = 19. Outcome measures: Pain and function were measured using the Western Ontario and McMaster Universities (WOMAC Osteoarthritis Index within the month before surgery and 1, 3 and 6 months after surgery. Demographic, medical and surgical factors were also measured, along with depression, social support and health-related quality of life. Results: No baseline differences in pain and function were seen among the three groups (p > 0.05. Adjusting for age, gender and contralateral joint involvement across the 6 postoperative months, participants with diabetes that impacted on routine activities had pain scores that were 8.3 points higher (indicating greater pain and function scores that were 5.4 points higher (indicating lower function than participants without diabetes. Participants with diabetes that doesn’t impact on routine activities had similar recovery to those without diabetes. Conclusion: People undergoing TKA who report preoperatively that diabetes impacts on their routine activities have less recovery over 6 months than those without diabetes or those with diabetes that does not impact on routine activities

  16. Hybrid magnetic mechanism for active locomotion based on inchworm motion

    Science.gov (United States)

    Kim, Sung Hoon; Hashi, Shuichiro; Ishiyama, Kazushi

    2013-02-01

    Magnetic robots have been studied in the past. Insect-type micro-robots are used in various biomedical applications; researchers have developed inchworm micro-robots for endoscopic use. A biological inchworm has a looping locomotion gait. However, most inchworm micro-robots depend on a general bending, or bellows, motion. In this paper, we introduce a new robotic mechanism using magnetic force and torque control in a rotating magnetic field for a looping gait. The proposed robot is controlled by the magnetic torque, attractive force, and body mechanisms (two stoppers, flexible body, and different frictional legs). The magnetic torque generates a general bending motion. In addition, the attractive force and body mechanisms produce the robot’s looping motion within a rotating magnetic field and without the use of an algorithm for field control. We verified the device’s performance and analyzed the motion through simulations and various experiments. The robot mechanism can be applied to active locomotion for various medical robots, such as wireless endoscopes.

  17. Impact on gait biomechanics of using an active variable impedance prosthetic knee

    OpenAIRE

    Williams, Matthew R; D’Andrea, Susan; Herr, Hugh M.

    2016-01-01

    Background An above knee amputation can have a significant impact on gait, with substantial deviations in inter-leg symmetry, step length, hip exertion and upper body involvement even when using a current clinical standard of care prosthesis. These differences can produce gait that is less efficient and less comfortable, resulting in slower and shorter distance walking, particularly with long term use. Methods A robotic variable impedance prosthetic knee (VI Knee) was tested with five individ...

  18. Prognosis of limitations in activities in osteoarthritis of the hip or knee: a 3-year cohort study.

    NARCIS (Netherlands)

    Dijk, G.M. van; Veenhof, C.; Spreeuwenberg, P.; Coene, N.; Burger, B.J.; Schaardenburg, D. van; Ende, C.H.M. van den; Lankhorst, G.J.; Dekker, J.

    2010-01-01

    van Dijk GM, Veenhof C, Spreeuwenberg P, Coene N, Burger BJ, van Schaardenburg D, van den Ende CH, Lankhorst GJ, Dekker J, on behalf of the CARPA Study Group. Prognosis of limitations in activities in osteoarthritis of the hip or knee: a 3-year cohort study. OBJECTIVE: To describe the course of limi

  19. Physical activity and exercise adherence in physical therapy exercise treatment in patients with osteoarthritis of hip or knee.

    NARCIS (Netherlands)

    Pisters, M.F.; Veenhof, C.; Bakker, D. de; Schellevis, F.G.; Dekker, J.

    2008-01-01

    Purpose: a lack of regular physical activity in patients with osteoarthritis (OA) of the hip and/or knee is an important risk factor for functional decline. The ultimate goal of exercise therapy is to improve the overall physical function and to help individuals meet the demands of daily living. Ear

  20. Effectiveness of behavioral graded activity in patients with osteoarthritis of hip and/or knee: a randomized clinical trial.

    NARCIS (Netherlands)

    Veenhof, C.; Köke, A.J.A.; Dekker, J.; Oostendorp, R.A.; Bijlsma, J.W.J.; Tulder, M.W. van; Ende, C.H.M. van den

    2006-01-01

    Objective: To determine the effectiveness of a behavioral graded activity program (BGA) compared with usual care (UC; exercise therapy and advice) according to the Dutch guidelines for physiotherapy in patients with osteoarthritis (OA) of the hip and/or knee. The BGA intervention is intended to incr

  1. Effectiveness of behavioral graded activity in patients with osteoarthritis of the hip and/or knee: A randomized clinical trial.

    NARCIS (Netherlands)

    Veenhof, C.; Koke, A.J.; Dekker, J.; Oostendorp, R.A.B.; Bijlsma, J.W.J.; Tulder, M.W. van; Ende, C.H.M. van den

    2006-01-01

    OBJECTIVE: To determine the effectiveness of a behavioral graded activity program (BGA) compared with usual care (UC; exercise therapy and advice) according to the Dutch guidelines for physiotherapy in patients with osteoarthritis (OA) of the hip and/or knee. The BGA intervention is intended to incr

  2. The cost-effectiveness of a behavioral graded activity in patients with osteoarthritis of hip and/or knee.

    NARCIS (Netherlands)

    Coupé, V.M.H.; Veenhof, C.; Tulder, M.W. van; Dekker, J.; Bijlsma, J.W.J.; Ende, C.H.M. van den

    2007-01-01

    OBJECTIVE: To evaluate whether exercise treatment based on behavioural graded activity comprising booster sessions is a cost-effective treatment for patients with osteoarthritis of the hip and/or knee compared with usual care. METHODS: An economic evaluation from a societal perspective was carried o

  3. Strength asymmetry of the knee extensors and physical activity in middle-aged women

    Directory of Open Access Journals (Sweden)

    Michal Lehnert

    2014-09-01

    Full Text Available Background: Differences between muscle strength and power of lower limbs is one of the factors associated with falls in the elderly population. Muscle strength asymmetry of lower limbs increases with age. Objective: The aim of the study is to assess differences in the volume and intensity of physical activity (PA in the subgroups of women being at higher and lower risk of falls (with and without strength asymmetry of the knee extensors of dominant and non-dominant lower limb. Methods: Data from 42 women (age 56.3 ± 4.4 years; weight 76.5 ± 16.1 kg; body height 164.3 ± 5.2 cm; body mass index 28.1 ± 5.3 kg . m-2 were used for the purpose of the presented analysis. Furthermore the sample was divided into subgroups with lower and higher strength asymmetry of quadriceps muscle (as a criterion the asymmetry greater than 15% was chosen. Absolute concentric peak torque of the knee extensors was evaluated by an isokinetic dynamometer IsoMed 2000 in a sitting position at angular velocity of 180° . s-1. PA was monitored using Yamax SW-700 pedometers throughout 7 consecutive days and using the Czech version of standardized International Physical Activity Questionnaire. Results: Statistically significant differences between groups with lower and higher strength asymmetry were found in the amount of self-reported vigorous PA (p = .04; d = 0.6 only. Differences between the observed groups were not significant in self-reported moderate PA and walking. There were also no significant differences in the daily numbers of steps measured objectively. Conclusions: The results of the study indicate that from the point of view of strength asymmetry of knee extensors as a factor associated with falls in middle-aged women, intensity of PA could be an important characteristic of PA. This suggestion should be taken into account in habitual PA and training programs in middle-aged population.

  4. In Vivo Healthy Knee Kinematics during Dynamic Full Flexion

    Directory of Open Access Journals (Sweden)

    Satoshi Hamai

    2013-01-01

    Full Text Available Healthy knee kinematics during dynamic full flexion were evaluated using 3D-to-2D model registration techniques. Continuous knee motions were recorded during full flexion in a lunge from 85° to 150°. Medial and lateral tibiofemoral contacts and femoral internal-external and varus-valgus rotations were analyzed as a function of knee flexion angle. The medial tibiofemoral contact translated anteroposteriorly, but remained on the center of the medial compartment. On the other hand, the lateral tibiofemoral contact translated posteriorly to the edge of the tibial surface at 150° flexion. The femur exhibited external and valgus rotation relative to the tibia over the entire activity and reached 30° external and 5° valgus rotations at 150° flexion. Kinematics’ data during dynamic full flexion may provide important insight as to the designing of high-flexion total knee prostheses.

  5. Motion sickness and tilts of the inertial force environment: active suspension systems vs. active passengers

    NARCIS (Netherlands)

    Golding, J.F.; Bles, W.; Bos, J.E.; Haynes, T.; Gresty, M.A.

    2003-01-01

    Maneuvering in vehicles exposes occupants to low frequency forces (<1 Hz) which can provoke motion sickness. Hypothesis: Aligning with the tilting inertial resultant (gravity + imposed horizontal acceleration: gravito-inertial force (GIF)) may reduce motion sickness when tilting is either 'active' (

  6. Autonomous Motion Learning for Intra-Vehicular Activity Space Robot

    Science.gov (United States)

    Watanabe, Yutaka; Yairi, Takehisa; Machida, Kazuo

    Space robots will be needed in the future space missions. So far, many types of space robots have been developed, but in particular, Intra-Vehicular Activity (IVA) space robots that support human activities should be developed to reduce human-risks in space. In this paper, we study the motion learning method of an IVA space robot with the multi-link mechanism. The advantage point is that this space robot moves using reaction force of the multi-link mechanism and contact forces from the wall as space walking of an astronaut, not to use a propulsion. The control approach is determined based on a reinforcement learning with the actor-critic algorithm. We demonstrate to clear effectiveness of this approach using a 5-link space robot model by simulation. First, we simulate that a space robot learn the motion control including contact phase in two dimensional case. Next, we simulate that a space robot learn the motion control changing base attitude in three dimensional case.

  7. Physical performance and self-report outcomes associated with use of passive, adaptive, and active prosthetic knees in persons with unilateral, transfemoral amputation: Randomized crossover trial

    Directory of Open Access Journals (Sweden)

    Brian J. Hafner, PhD

    2015-09-01

    Full Text Available Prosthetic knees are a vital component in an artificial limb. Contemporary knees include passive (mechanical, adaptive (computerized, or active (motorized control systems and have the potential to mitigate amputation-related functional impairments and activity limitations. A 14 mo randomized crossover trial was conducted. Participants (n = 12, mean age = 58 yr were tested under three conditions: passive control (existing knee, adaptive control (Ossur Rheo Knee II, and active control (Ossur Power Knee II. Training and acclimation time were provided to participants in the adaptive and active knees. Outcome measures included indoor tests (Timed Up and Go test [TUG], stairs, and ramp, outdoor tests (walking course and perceived exertion, step activity monitor, self-report surveys (mobility, balance confidence, physical function, fatigue, and general health, and fall incidence. Mixed-effects linear regression modeling was used to evaluate data. Compared with passive control, adaptive control significantly improved comfortable TUG time (difference = 0.91 s, p = 0.001 and reported physical function (difference = 1.26 [T-score], p = 0.03. Active control significantly increased comfortable TUG, fast TUG, and ramp times (difference = 3.02, 2.66, and 0.96 s, respectively, all p < 0.03 and increased balance confidence (difference = 3.77, p = 0.003 compared with passive control. Findings suggest that adaptive knee control may enhance function compared with passive control but that active control can restrict mobility in middle-age or older users with transfemoral amputation.

  8. Motion of Euglena Gracilis: Active Fluctuations and Velocity Distribution

    CERN Document Server

    Romanczuk, Pawel; Scholz, Dimitri; Lobaskin, Vladimir; Schimansky-Geier, Lutz

    2015-01-01

    We study the velocity distribution of unicellular swimming algae Euglena gracilis using optical microscopy and theory. To characterize a peculiar feature of the experimentally observed distribution at small velocities we use the concept of active fluctuations, which was recently proposed for the description of stochastically self-propelled particles [Romanczuk, P. and Schimansky-Geier, L., Phys. Rev. Lett. 106, 230601 (2011)]. In this concept, the fluctuating forces arise due to internal random performance of the propulsive motor. The fluctuating forces are directed in parallel to the heading direction, in which the propulsion acts. In the theory, we introduce the active motion via the depot model [Schweitzer et al., Phys. Rev. Lett. 80, 23, 5044 (1998)]. We demonstrate that the theoretical predictions based on the depot model with active fluctuations are consistent with the experimentally observed velocity distributions. In addition to the model with additive active noise, we obtain theoretical results for a...

  9. Fusion of smartphone motion sensors for physical activity recognition.

    Science.gov (United States)

    Shoaib, Muhammad; Bosch, Stephan; Incel, Ozlem Durmaz; Scholten, Hans; Havinga, Paul J M

    2014-06-10

    For physical activity recognition, smartphone sensors, such as an accelerometer and a gyroscope, are being utilized in many research studies. So far, particularly, the accelerometer has been extensively studied. In a few recent studies, a combination of a gyroscope, a magnetometer (in a supporting role) and an accelerometer (in a lead role) has been used with the aim to improve the recognition performance. How and when are various motion sensors, which are available on a smartphone, best used for better recognition performance, either individually or in combination? This is yet to be explored. In order to investigate this question, in this paper, we explore how these various motion sensors behave in different situations in the activity recognition process. For this purpose, we designed a data collection experiment where ten participants performed seven different activities carrying smart phones at different positions. Based on the analysis of this data set, we show that these sensors, except the magnetometer, are each capable of taking the lead roles individually, depending on the type of activity being recognized, the body position, the used data features and the classification method employed (personalized or generalized). We also show that their combination only improves the overall recognition performance when their individual performances are not very high, so that there is room for performance improvement. We have made our data set and our data collection application publicly available, thereby making our experiments reproducible.

  10. Fusion of Smartphone Motion Sensors for Physical Activity Recognition

    Directory of Open Access Journals (Sweden)

    Muhammad Shoaib

    2014-06-01

    Full Text Available For physical activity recognition, smartphone sensors, such as an accelerometer and a gyroscope, are being utilized in many research studies. So far, particularly, the accelerometer has been extensively studied. In a few recent studies, a combination of a gyroscope, a magnetometer (in a supporting role and an accelerometer (in a lead role has been used with the aim to improve the recognition performance. How and when are various motion sensors, which are available on a smartphone, best used for better recognition performance, either individually or in combination? This is yet to be explored. In order to investigate this question, in this paper, we explore how these various motion sensors behave in different situations in the activity recognition process. For this purpose, we designed a data collection experiment where ten participants performed seven different activities carrying smart phones at different positions. Based on the analysis of this data set, we show that these sensors, except the magnetometer, are each capable of taking the lead roles individually, depending on the type of activity being recognized, the body position, the used data features and the classification method employed (personalized or generalized. We also show that their combination only improves the overall recognition performance when their individual performances are not very high, so that there is room for performance improvement. We have made our data set and our data collection application publicly available, thereby making our experiments reproducible.

  11. Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis.

    Directory of Open Access Journals (Sweden)

    Kimberly A Ingraham

    Full Text Available Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed.

  12. Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis.

    Science.gov (United States)

    Ingraham, Kimberly A; Fey, Nicholas P; Simon, Ann M; Hargrove, Levi J

    2016-01-01

    Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed.

  13. Assessing the Relative Contributions of Active Ankle and Knee Assistance to the Walking Mechanics of Transfemoral Amputees Using a Powered Prosthesis

    Science.gov (United States)

    Simon, Ann M.; Hargrove, Levi J.

    2016-01-01

    Powered knee-ankle prostheses are capable of providing net-positive mechanical energy to amputees. Yet, there are limitless ways to deliver this energy throughout the gait cycle. It remains largely unknown how different combinations of active knee and ankle assistance affect the walking mechanics of transfemoral amputees. This study assessed the relative contributions of stance phase knee swing initiation, increasing ankle stiffness and powered plantarflexion as three unilateral transfemoral amputees walked overground at their self-selected walking speed. Five combinations of knee and ankle conditions were evaluated regarding the kinematics and kinetics of the amputated and intact legs using repeated measures analyses of variance. We found eliminating active knee swing initiation or powered plantarflexion was linked to increased compensations of the ipsilateral hip joint during the subsequent swing phase. The elimination of knee swing initiation or powered plantarflexion also led to reduced braking ground reaction forces of the amputated and intact legs, and influenced both sagittal and frontal plane loading of the intact knee joint. Gradually increasing prosthetic ankle stiffness influenced the shape of the prosthetic ankle plantarflexion moment, more closely mirroring the intact ankle moment. Increasing ankle stiffness also corresponded to increased prosthetic ankle power generation (despite a similar maximum stiffness value across conditions) and increased braking ground reaction forces of the amputated leg. These findings further our understanding of how to deliver assistance with powered knee-ankle prostheses and the compensations that occur when specific aspects of assistance are added/removed. PMID:26807889

  14. Degenerative joint disease on MRI and physical activity: a clinical study of the knee joint in 320 patients

    International Nuclear Information System (INIS)

    We examined 320 patients with MRI and arthroscopy after an acute trauma to evaluate MRI in diagnosis of degenerative joint disease of the knee in relation to sports activity and clinical data. Lesions of cartilage and menisci on MRI were registered by two radiologists in consensus without knowledge of arthroscopy. Arthroscopy demonstrated grade-1 to grade-4 lesions of cartilage on 729 of 1920 joint surfaces of 320 knees, and MRI diagnosed 14 % of grade-1, 32 % of grade-2, 94 % of grade-3, and 100 % of grade-4 lesions. Arthroscopy explored 1280 meniscal areas and showed degenerations in 10 %, tears in 11.4 %, and complex lesions in 9.2 %. Magnetic resonance imaging was in agreement with arthroscopy in 81 % showing more degenerations but less tears of menisci than arthroscopy. Using a global system for grading the total damage of the knee joint into none, mild, moderate, or severe changes, agreement between arthroscopy and MRI was found in 82 %. Magnetic resonance imaging and arthroscopy showed coherently that degree of degenerative joint changes was significantly correlated to patient age or previous knee trauma. Patients over 40 years had moderate to severe changes on MRI in 45 % and patients under 30 years in only 22 %. Knee joints with a history of trauma without complete structural or functional reconstitution showed marked changes on MRI in 57 %, whereas stable joints without such alterations had degenerative changes in only 26 %. There was no correlation of degenerative disease to gender, weight, type, frequency, and intensity of sports activity. Therefore, MRI is an effective non-invasive imaging method for exact localization and quantification of chronic joint changes of cartilage and menisci that recommends MRI for monitoring in sports medicine. (orig.) (orig.)

  15. Design and Control of an Active Electrical Knee and Ankle Prosthesis

    OpenAIRE

    Sup, Frank; Varol, Huseyin Atakan; Mitchell, Jason; Withrow, Thomas; Goldfarb, Michael

    2008-01-01

    This paper presents an overview of the design and control of an electrically powered knee and ankle prosthesis. The prosthesis design incorporates two motor-driven ball screw units to drive the knee and ankle joints. A spring in parallel with the ankle motor unit is employed to decrease the power consumption and increase the torque output for a given motor size. The device’s sensor package includes a custom load cell to measure the sagittal socket interface moment above the knee joint, a cust...

  16. Movement detection impaired in patients with knee osteoarthritis compared to healthy controls

    DEFF Research Database (Denmark)

    Lund, H; Juul-Kristensen, Birgit; Hansen, Klaus;

    2009-01-01

    The purpose of this study was to clarify whether osteoarthritis (OA) patients have a localized or a generalized reduction in proprioception. Twenty one women with knee OA (mean age [SD]: 57.1 [12.0] years) and 29 healthy women (mean age [SD]: 55.3 [10.1] years) had their joint position sense (JPS......) and threshold to detection of a passive movement (TDPM) measured in both knees and elbows. JPS was measured as the participant's ability to actively reproduce the position of the elbow and knee joints. TDPM was measured as the participant's ability to recognize a passive motion of the elbow and knee joints....... The absolute error (AE) for JPS (i.e., absolute difference in degrees between target and estimated position) and for TDPM (i.e., the difference in degrees at movement start and response when recognizing the movement) was calculated. For TDPM a higher AE (mean [SE]) was found in the involved knees in patients...

  17. The effect of total knee arthroplasty on knee joint kinematics and kinetics during gait.

    Science.gov (United States)

    Hatfield, Gillian L; Hubley-Kozey, Cheryl L; Astephen Wilson, Janie L; Dunbar, Michael J

    2011-02-01

    This study determined how total knee arthroplasty (TKA) altered knee motion and loading during gait. Three-dimensional kinematic and kinetic gait patterns of 42 patients with severe knee osteoarthritis were collected 1 week prior and 1-year post-TKA. Principal component analysis extracted major patterns of variability in the gait waveforms. Overall and midstance knee adduction moment magnitude decreased. Overall knee flexion angle magnitude increased due to an increase during swing. Increases in the early stance knee flexion moment and late stance knee extension moment were found, indicating improved impact attenuation and function. A decrease in the early stance knee external rotation moment indicated alteration in the typical rotation mechanism. Most changes moved toward an asymptomatic pattern and would be considered improvements in motion, function, and loading.

  18. Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty.

    Science.gov (United States)

    Memişoğlu, Kaya; Müezzinoğlu, U Sefa; Kesemenli, Cumhur Cevdet

    2010-01-01

    The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year old male patient who had revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty performed 32 years after the initial operation. PMID:21343693

  19. Knee Problems

    Science.gov (United States)

    ... in Chinese 繁體中文 ) What Are Knee Problems? (in Korean 한국어 ) What Are Knee Problems? (in Vietnamese bằng ... the knee. Ultrasound. A technique that uses sound waves to produce images of the soft tissue structures ...

  20. Knee Injuries

    Science.gov (United States)

    ... of the knee. Sometimes fluid collects around the knee (this is called effusion ). Fractures and Dislocations A fracture is a cracked, broken, or shattered bone and is usually diagnosed by an X-ray. You may have trouble ... off to the side of the knee joint by twisting or some kind of impact. ...

  1. Documenting Western Burrowing Owl Reproduction and Activity Patterns Using Motion-Activated Cameras

    Energy Technology Data Exchange (ETDEWEB)

    Hall, Derek B. [NSTec; Greger, Paul D. [NSTec

    2014-08-01

    We used motion-activated cameras to monitor the reproduction and patterns of activity of the Burrowing Owl (Athene cunicularia) above ground at 45 burrows in south-central Nevada during the breeding seasons of 1999, 2000, 2001, and 2005. The 37 broods, encompassing 180 young, raised over the four years represented an average of 4.9 young per successful breeding pair. Young and adult owls were detected at the burrow entrance at all times of the day and night, but adults were detected more frequently during afternoon/early evening than were young. Motion-activated cameras require less effort to implement than other techniques. Limitations include photographing only a small percentage of owl activity at the burrow; not detecting the actual number of eggs, young, or number fledged; and not being able to track individual owls over time. Further work is also necessary to compare the accuracy of productivity estimates generated from motion-activated cameras with other techniques.

  2. Reliability and Validity of the Dutch Version of the International Physical Activity Questionnaire in Patients After Total Hip Arthroplasty or Total Knee Arthroplasty

    NARCIS (Netherlands)

    Blikman, Tim; Stevens, Martin; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge; Reininga, Inge H. F.

    2013-01-01

    STUDY DESIGN: Psychometric assessment. OBJECTIVES: To determine test-retest reliability and concurrent validity of the International Physical Activity Questionnaire (IPAQ) in patients after total hip arthroplasty or total knee arthroplasty. BACKGROUND: Despite recognized benefits of regular physical

  3. UTILIZATION OF PULSED ELECTROMAGNETIC FIELD AND TRADITIONAL PHYSIOTHERAPY IN KNEE OSTEOARTHRITIS MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Kadrya H. Battecha

    2015-04-01

    Full Text Available Background and Objectives: Pulsed electromagnetic field (PEMF has been suggested as a treatment method for musculoskeletal system disorders. The present study was conducted to determine whether the addition of PEMF to traditional physiotherapy produces better clinical outcomes than traditional physiotherapy alone in the management of moderate knee osteoarthritis (OA. Design: A single-blinded, randomized controlled study Methods: Twenty subjects (5 men and 15 women with unilateral moderate knee OA (Kellgren-Lawrence criteria grade 2. They were randomly allocated in 2 groups to receive: group (A PEMF plus ultrasound plus exercises; or (B ultrasound plus exercises. Both groups received the respective treatments 3 times per week for 4 weeks and underwent the same pretreatment and post treatment evaluation that included active knee range of motion (ROM by universal goniometer, knee pain score by visual analogue scale (VAS and knee functional performance by Western Ontario and McMaster Universities osteoarthritis index (WOMAC. Result: There was an improvement in both groups in active knee flexion ROM, reduced VAS score and improved WOMAC index , however, all outcomes were significantly better in group (A (p <0.05. Moreover, the percentages of outcomes improvement were in favor of group (A. Conclusion: The addition of PEMF to traditional physiotherapy in managing Knee OA produced a greater improvement in pain relief, range of motion and resulted in better functional performance than did traditional physiotherapy alone. The improvement in current study should be limited to short term outcomes of PEMF.

  4. The Effects of NMDA Antagonists on Neuronal Activity in Cat Spinal Cord Evoked by Acute Inflammation in the Knee Joint.

    Science.gov (United States)

    Schaible, Hans-Georg; Grubb, Blair D.; Neugebauer, Volker; Oppmann, Maria

    1991-01-01

    In alpha-chloralose-anaesthetized, spinalized cats we examined the effects of NMDA antagonists on the discharges of 71 spinal neurons which had afferent input from the knee joint. These neurons were rendered hyperexcitable by acute arthritis in the knee induced by kaolin and carrageenan. They were located in the deep dorsal and ventral horn and some of them had ascending axons. The N-methyl-d-aspartate (NMDA) antagonists ketamine and d-2-amino-5-phosphonovalerate (AP5), were administered ionophoretically, and ketamine was also administered intravenously. In some of the experiments the antagonists were tested against the agonists NMDA and quisqualate. The effects of the NMDA antagonists consisted of a significant reduction in the resting activity of neurons and/or the responses of the same neurons to mechanical stimulation of the inflamed knee. Intravenous ketamine was most effective in suppressing the resting and mechanically evoked activity in 25 of 26 neurons tested. Ionophoretically applied ketamine had a suppressive effect in 11 of 21 neurons, and AP5 decreased activity in 17 of 24 cells. The reduction in the resting and/or the mechanically evoked discharges was achieved with doses of the antagonists which suppressed the responses to NMDA but not those to quisqualate. These results suggest that NMDA receptors are involved in the enhanced responses and basal activity of spinal neurons induced by inflammation in the periphery. PMID:12106256

  5. Revision of the Gunston polycentric knee arthroplasty with total knee arthroplasty

    OpenAIRE

    Memisoglu, Kaya; Muezzinoglu, U. Sefa; Kesemenli, Cumhur Cevdet

    2011-01-01

    The Gunston polycentric knee arthroplasty, first designed and performed by Frank Gunston in 1971, is the first prosthesis considering the natural knee biomechanics. Although the polycentric knee arthroplasty showed encouraging results to relieve pain and to preserve the preoperative range of motion and joint instability, the improvements in prosthesis design and arthroplasty technology rapidly made the polycentric knee prosthesis obsolete. Herein, we report a 58-year-old male patient who had ...

  6. The effect of active recovery, cold water immersion and passive recovery on subsequent knee extension and flexion strength

    Directory of Open Access Journals (Sweden)

    Barbora Strejcová

    2012-09-01

    Full Text Available BACKGROUND: Recovery is an important aspect of every physical activity. Many athletes train hard without giving their body time to recover which can lead to overreaching, burnout or poor performance. Currently cold-water immersion recovery and active recovery have emerged as some of the most popular interventions enabling faster recovery. OBJECTIVE: To assess the effect of three kinds of recovery (active recovery, cold water immersion, passive recovery on medium-term knee strength in the extension and flexion. METHODS: Fourteen athletes at the age of 26.6 ± 4.4 years performed, in a random cross-over design, 3 sessions with 3 repeated medium-term isokinetic tests. The effect of active recovery, passive rest and cold water immersion were assessed by 3 × 3 (time × recovery repeated-measure ANOVA, respectively. The dependent variables were – peak torque, total work and average power. RESULTS: We found significantly lower absolute differences between the first and third trial in knee extension for peak torque after the active recovery (↑ 0.9 N × m than after the cold water immersion (↓ 14.6 N × m or the passive recovery (↓ 13.9 N × m. The decrease of the average power was significantly lower differences after the active recovery (↓ 5 W than after the cold water immersion (↓ 23.7 W or passive recovery (↓ 25.9 W. The changes in total work were not significant. We did not found any changes in the isokinetic strength for the knee flexors after different kinds of recovery. Maximal heart rate (HRmax was significantly higher during the active recovery than during the cold water immersion and the passive recovery (173 ± 14, 166 ± 14 and 167 ± 14 rpm. We have found significant differences in the average heart rates (HRavg during active recovery, cold water immersion and passive recovery (124 ± 8, 97 ± 9 and 107 ± 12 rpm. CONCLUSION: We found the positive effect of the active recovery on the subsequent medium-term performance for

  7. Prosthetic knee design by simulation

    Energy Technology Data Exchange (ETDEWEB)

    Hollerbach, K; Hollister, A

    1999-07-30

    Although 150,000 total knee replacement surgeries are performed annually in North America, current designs of knee prostheses have mechanical problems that include a limited range of motion, abnormal gait patterns, patellofemoral joint dysfunction, implant loosening or subsidence, and excessive wear. These problems fall into three categories: failure to reproduce normal joint kinematics, which results in altered limb function; bone-implant interface failure; and material failure. Modern computer technology can be used to design, prototype, and test new total knee implants. The design team uses the full range of CAD-CAM to design and produce implant prototypes for mechanical and clinical testing. Closer approximation of natural knee kinematics and kinetics is essential for improved patient function and diminished implant loads. Current knee replacement designs are based on 19th Century theories that the knee moves about a variable axis of rotation. Recent research has shown, however, that knee motion occurs about two fixed, offset axes of rotation. These aces are not perpendicular to the long axes of the bones or to each other, and the axes do not intersect. Bearing surfaces of mechanisms that move about axes of rotation are surfaces of revolution of those axes which advanced CAD technology can produce. Solids with surfaces of revolution for the two axes of rotation for the knee have been made using an HP9000 workstation and Structural Ideas Master Series CAD software at ArthroMotion. The implant's CAD model should closely replicate movements of the normal knee. The knee model will have a range of flexion-extension (FE) from -5 to 120 degrees. Movements include varus, valgus, internal and external rotation, as well as flexion and extension. The patellofemoral joint is aligned perpendicular to the FE axis and replicates the natural joint more closely than those of existing prostheses. The bearing surfaces will be more congruent than current designs and should

  8. Quantifying thigh muscle co-activation during isometric knee extension contractions: within- and between-session reliability.

    Science.gov (United States)

    Katsavelis, Dimitrios; Threlkeld, A Joseph

    2014-08-01

    Muscle co-activation around the knee is important during ambulation and balance. The wide range of methodological approaches for the quantification of co-activation index (CI) makes comparisons across studies and populations difficult. The present study determined within- and between-session reliability of different methodological approaches for the quantification of the CI of the knee extensor and flexor muscles during maximum voluntary isometric contractions (MVICs). Eight healthy volunteers participated in two repeated testing sessions. A series of knee extension MVICs of the dominant leg with concomitant torque and electromyographic (EMG) recordings were captured. CI was calculated utilizing different analytical approaches. Intraclass correlation coefficient (ICC) showed that within-session measures displayed higher reliability (ICC>0.861) and lower variability (Coefficient of variation; CV24.2%). A selection of a 500ms or larger window of RMS EMG activity around the PT delivered more reliable and less variable results than other approaches. Our findings suggest that the CI can provide a reliable measure for comparisons among conditions and is best utilized for within-session experimental designs.

  9. Within- and between-session reliability of the maximal voluntary knee extension torque and activation.

    Science.gov (United States)

    Park, Jihong; Hopkins, J Ty

    2013-01-01

    A ratio between the torque generated by maximal voluntary isometric contraction (MVIC) and exogenous electrical stimulus, central activation ratio (CAR), has been widely used to assess quadriceps function. To date, no data exist regarding between-session reliability of this measurement. Thirteen neurologically sound volunteers underwent three testing sessions (three trials per session) with 48 hours between-session. Subjects performed MVICs of the quadriceps with the knee locked at 90° flexion and the hip at 85°. Once the MVIC reached a plateau, an electrical stimulation from superimposed burst technique (SIB: 125 V with peak output current 450 mA) was manually delivered and transmitted directly to the quadriceps via stimulating electrodes. CAR was calculated by using the following equation: CAR = MVIC torque/MVIC + SIB torque. Intraclass correlation coefficients (ICC) were calculated within- (ICC((2,1))) and between-session (ICC((2,k))) for MVIC torques and CAR values. Our data show that quadriceps MVIC and CAR are very reliable both within- (ICC((2,1)) = 0.99 for MVIC; 0.94 for CAR) and between-measurement sessions (ICC((2,k)) = 0.92 for MVIC; 0.86 for CAR) in healthy young adults. For clinical research, more data of the patients with pathological conditions are required to ensure reproducibility of calculation of CAR.

  10. A mid term comparison of open wedge high tibial osteotomy vs unicompartmental knee arthroplasty for medial compartment osteoarthritis of the knee

    Directory of Open Access Journals (Sweden)

    Takeuchi Ryohei

    2010-08-01

    Full Text Available Abstract Background The choice of surgical treatments for unicompartmental osteoarthritis (OA of the knee is still somewhat controversial. Midterm results from cases treated using unicompartmental knee arthroplasty (UKA or open wedge high tibial osteotomy (OWHTO were evaluated retrospectively. Methods Twenty-seven knees of 24 patients with varus deformities underwent OWHTO and 30 knees of 18 patients underwent UKA surgeries for the treatment of medial compartmental osteoarthritis (OA. The KSS score, FTA, range of motion and complications were evaluated before and after surgery. Results The preoperative mean KSS scores were 49 points in the OWHTO group and 62 in the UKA group which improved postoperatively to 89 (excellent; 19 knees, good; 8 knees, and 88 (excellent; 25, good; 4, fair; 1, respectively. There was no significant difference between the OWHTO and UKA scores. Seventeen patients in the OWHTO group could sit comfortably in the formal Japanese style after surgery. The preoperative mean FTA values for the OWHTO and UKA groups were 182 degrees and 184, and at follow-up measured 169 and 170, respectively. In the UKA group, the femoral component and the polyethylene insertion in one patient was exchanged at 5 years post-surgery and revision TKAs were performed in 2 cases. In the OWHTO group, one tibial plateau fracture and one subcutaneous tissue infection were noted. Conclusions Treatment options should be carefully considered for each OA patient in accordance with their activity levels, grade of advanced OA, age, and range of motion of the knee. OWHTO shows an improved indication for active patients with a good range of motion of the knee.

  11. Effects of therapeutic exercise and hydrotherapy on pain severity and knee range of motion in patients with hemophilia: A randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Vahid Mazloum

    2014-01-01

    Conclusions: Using hydrotherapy in addition to usual rehabilitation training can result in beneficial effect in terms of pain and knee joint ROM. However, it appears that hydrotherapy is more effective in reducing pain.

  12. Effect of knee joint icing on knee extension strength and knee pain early after total knee arthroplasty: a randomized cross-over study

    DEFF Research Database (Denmark)

    Holm, Bente; Husted, Henrik; Kehlet, Henrik;

    2012-01-01

    Objective: To investigate the acute effect of knee joint icing on knee extension strength and knee pain in patients shortly after total knee arthroplasty.Design: A prospective, single-blinded, randomized, cross-over study.Setting: A fast-track orthopaedic arthroplasty unit at a university hospital.......Participants: Twenty patients (mean age 66 years; 10 women) scheduled for primary unilateral total knee arthroplasty.Interventions: The patients were treated on two days (day 7 and day 10) postoperatively. On one day they received 30 minutes of knee icing (active treatment) and on the other day they received 30...... minutes of elbow icing (control treatment). The order of treatments was randomized.Main outcome measures: Maximal knee extension strength (primary outcome), knee pain at rest and knee pain during the maximal knee extensions were measured 2-5 minutes before and 2-5 minutes after both treatments by an...

  13. The use of the greater trochanter marker in the thigh segment model:Implications for hip and knee frontal and transverse plane motion

    Institute of Scientific and Technical Information of China (English)

    Valentina Graci; Gretchen B. Salsich

    2016-01-01

    Background: The greater trochanter marker is commonly used in 3-dimensional (3D) models; however, its influence on hip and knee kinematics during gait is unclear. Understanding the influence of the greater trochanter marker is important when quantifying frontal and transverse plane hip and knee kinematics, parameters which are particularly relevant to investigate in individuals with conditions such as patellofemoral pain, knee osteoarthritis, anterior cruciate ligament (ACL) injury, and hip pain. The aim of this study was to evaluate the effect of including the greater trochanter in the construction of the thigh segment on hip and knee kinematics during gait. Methods: 3D kinematics were collected in 19 healthy subjects during walking using a surface marker system. Hip and knee angles were compared across two thigh segment definitions (with and without greater trochanter) at two time points during stance:peak knee flexion (PKF) and minimum knee flexion (MinKF). Results: Hip and knee angles differed in magnitude and direction in the transverse plane at both time points. In the thigh model with the greater trochanter the hip was more externally rotated than in the thigh model without the greater trochanter (PKF:−9.34° ± 5.21° vs. 1.40° ± 5.22°, MinKF:−5.68° ± 4.24° vs. 5.01° ± 4.86°;p<0.001). In the thigh model with the greater trochanter, the knee angle was more internally rotated compared to the knee angle calculated using the thigh definition without the greater trochanter (PKF:14.67° ± 6.78° vs. 4.33° ± 4.18°, MinKF:10.54° ± 6.71° vs.−0.01° ± 2.69°;p<0.001). Small but significant differences were detected in the sagittal and frontal plane angles at both time points (p<0.001). Conclusion: Hip and knee kinematics differed across different segment definitions including or excluding the greater trochanter marker, especially in the transverse plane. Therefore when considering whether to include the greater trochanter in the thigh segment

  14. Construction of an in vivo motion evaluation system for the knee joint of athletes%运动员膝关节在体运动检测系统的建立

    Institute of Scientific and Technical Information of China (English)

    宋军; 李凭跃; 游辅宇; 孔祥雪; 肖菊姣; 李鉴轶

    2013-01-01

    目的 探讨利用2D/3D图像配准技术建立运动员膝关节在体运动检测系统的可行性.方法 采集1名健康成年志愿者(男性,37岁)左侧膝关节的CT影像,进行三维重建获得骨结构的三维模型.取志愿者保持约30°屈曲的2张X线片,在3Ds Max7软件系统中构建虚拟X线系统,采用2D/3D图像配准技术重现膝关节的位置,将CT数据中胫骨作为配准基点并利用逆向工程技术计算摄X线片时膝关节的相对运动. 结果 经2D/3D图像配准可还原膝关节的三维空间位置.逆向工程技术计算结果显示:与采集CT数据时的位置相比,摄X线片时左侧股骨下段相对位移X轴为0.01mm,Y轴为5.20 mm,Z轴为2.05 mm;相对角度X轴为26.67°,Y轴为-0.97°,Z轴为-15.14°. 结论 利用2D/3D图像配准技术可实现膝关节的在体运动评价,但其配准效率尚需进一步研究.%Objective To construct an in vivo motion evaluation system for the knee joint of athletes using 2D/3D registration.Methods CT data of the left knee from a male 37-year-old healthy adult volunteer were collected for 3D reconstruction of computer model of the knee joint.Two orthogonal images of the knee at a 30° flexion angle were captured using 2 C-arm fluoroscopic machines that were perpendicular to each other.A virtual fluoroscopy was then created in software 3Ds Max for reconstruction of the relative positions of the 2 orthogonal images.The 3D computer models of the left femur and tibia were then introduced into the virtual fluoroscopy respectively before they were projected onto the orthogonal images by 2 virtual cameras.The 3D positions of the knee joint were determined by matching the projections of the knee model to the orthogonal images of the knee.After the tibia in the CT data was taken as the base position for registration,the relatively displacements and angles of the femur were calculated with the reverse engineering technique.Results After 2D/3D registration,the 3D positions

  15. Unwinding motion of a twisted active-region filament

    CERN Document Server

    Yan, X L; Liu, J H; Kong, D F; Xu, C L

    2014-01-01

    To better understand the structures of active-region filaments and the eruption process, we study an active-region filament eruption in active region NOAA 11082 in detail on June 22, 2010. Before the filament eruption, the opposite unidirectional material flows appeared in succession along the spine of the filament. The rising of the filament triggered two B-class flares at the upper part of the filament. As the bright material was injected into the filament from the sites of the flares, the filament exhibited a rapid uplift accompanying the counterclockwise rotation of the filament body. From the expansion of the filament, we can see that the filament is consisted of twisted magnetic field lines. The total twist of the filament is at least 5$\\pi$ obtained by using time slice method. According to the morphology change during the filament eruption, it is found that the active-region filament was a twisted flux rope and its unwinding motion was like a solar tornado. We also find that there was a continuous magn...

  16. Knee kinematics and kinetics in former soccer players with a 16-year-old ACL injury – the effects of twelve weeks of knee-specific training

    Directory of Open Access Journals (Sweden)

    Holmström Eva

    2007-04-01

    Full Text Available Abstract Background Training of neuromuscular control has become increasingly important and plays a major role in rehabilitation of subjects with an injury to the anterior cruciate ligament (ACL. Little is known, however, of the influence of this training on knee stiffness during loading. Increased knee stiffness occurs as a loading strategy of ACL-injured subjects and is associated with increased joint contact forces. Increased or altered joint loads contribute to the development of osteoarthritis. The aim of the study was to determine if knee stiffness, defined by changes in knee kinetics and kinematics of gait, step activity and cross-over hop could be reduced through a knee-specific 12-week training programme. Methods A 3-dimensional motion analysis system (VICON and a force plate (AMTI were used to calculate knee kinetics and kinematics before and after 12 weeks of knee-specific training in 12 males recruited from a cohort with ACL injury 16 years earlier. Twelve uninjured males matched for age, sex, BMI and activity level served as a reference group. Self-reported patient-relevant data were obtained by the KOOS questionnaire. Results There were no significant changes in knee stiffness during gait and step activity after training. For the cross-over hop, increased peak knee flexion during landing (from 44 to 48 degrees, p = 0.031 and increased internal knee extensor moment (1.28 to 1.55 Nm/kg, p = 0.017 were seen after training, indicating reduced knee stiffness. The KOOS sport and recreation score improved from 70 to 77 (p = 0.005 and was significantly correlated with the changes in knee flexion during landing for the cross-over hop (r = 0.6, p = 0.039. Conclusion Knee-specific training improved lower extremity kinetics and kinematics, indicating reduced knee stiffness during demanding hop activity. Self-reported sport and recreational function correlated positively with the biomechanical changes supporting a clinical importance of the

  17. Influence factors of range of motion after total knee arthroplasty%影响全膝关节置换术后关节活动度的相关因素分析

    Institute of Scientific and Technical Information of China (English)

    曾勉东; 杨波; 谢景开; 吕玉明; 尹彪

    2012-01-01

    目的 分析全膝关节置换术后关节活动度的相关影响因素,旨在探讨如何提高术后膝关节活动范围.方法 回顾性研究2008年10月~2010年10月37例全膝关节置换术.术后1年25例膝关节屈曲度>90°的患者作为对照组,12例膝关节屈曲度<90°的患者作为实验组.两组根据年龄、性别、体重指数(BMI)、手术时间、术中出血和随访时间等进行配对病例对照研究分析影响因素.结果 两组患者年龄、性别、手术时间、术中出血、随访时间及术前合并症比较,差异无统计学意义.手术前后两组膝关节屈曲度比较,差异有显著统计学意义(P<0.01).手术前后两组的胫骨倾斜度与关节力线对位不良的比较,差异有统计学意义(P<0.05).结论 全膝关节置换术后膝关节活动度受肥胖、下肢力线对位情况和术后主动功能锻炼等因素影响,术中术后减少以上因素影响可以提高膝关节术后活动度.%Objective To analyze the related factors of the range of motion(ROM) after total knee arthroplasty and discuss how to improve the ROM of knee. Methods A retrospective review was given to the data from 37 patients undergoing total knee arthroplasty between October 2008 and October 2010. There're 25 TKA patients with greater than 90° flexion at 1 year postoperative served as control group, 12 patients with a 1 -year postoperative flexion range of less than 90° was taken as treatment group. The age, sex, body mass index, time for surgery, intraoperative bleeding, follow-up time of the control group were matched to those of the treatment group. Results No significant differences were found with regard to the age,sex,body mass index, time for surgery, intraoperative bleeding, follow-up time. Significant differences were found between preoperative flexion and postopeartive flexion (P <0.01). Preoperative and postoperative the gradient of tibial and force line of lower extremities were significantly

  18. Effect of two different kinesio taping techniques on knee kinematics and kinetics in young females.

    Science.gov (United States)

    Guner, Senem; Alsancak, Serap; Koz, Mitat

    2015-10-01

    [Purpose] The application of kinesio taping may improve strength and performance, inhibit and facilitate motor activity, and increase range of motion. The aim of this study was to compare the effects of kinesio taping facilitation and inhibition applications on spatiotemporal knee kinematics and kinetics during walking activity in healthy subjects. [Subjects and Methods] A three-dimensional quantitative gait evaluation was performed without tape and with, facilitation and inhibition kinesio taping application on the knee. Sixteen healthy female college students (age, 19.7 ± 0.4 years; height, 1.64 ± 3.4 cm; body mass, 51.5 ± 4.8 kg) participated in the study. [Results] Spatiotemporal parameters (cadence, walking speed, stride length) were significantly different among the trials. Knee joint sagittal plane range of motion was not different with either kinesio taping application. Knee external flexion moment during the early stance phase decreased significantly with facilitation kinesio taping and increased with the inhibition kinesio taping. Knee external extension moment during the mid-stance phase increased with facilitation kinesio taping. Knee power parameters, eccentric activity in the rectus femoris during the pre-swing phase was significantly increased with inhibition kinesio taping application, while eccentric activity of the hamstrings during the terminal swing of gait was decreased. [Conclusion] These findings showed that facilitation kinesio taping application affected the terminal stance phase and that inhibition kinesio taping influenced the terminal swing phase compared with the no tape condition.

  19. Effect of two different kinesio taping techniques on knee kinematics and kinetics in young females

    Science.gov (United States)

    Guner, Senem; Alsancak, Serap; Koz, Mitat

    2015-01-01

    [Purpose] The application of kinesio taping may improve strength and performance, inhibit and facilitate motor activity, and increase range of motion. The aim of this study was to compare the effects of kinesio taping facilitation and inhibition applications on spatiotemporal knee kinematics and kinetics during walking activity in healthy subjects. [Subjects and Methods] A three-dimensional quantitative gait evaluation was performed without tape and with, facilitation and inhibition kinesio taping application on the knee. Sixteen healthy female college students (age, 19.7 ± 0.4 years; height, 1.64 ± 3.4 cm; body mass, 51.5 ± 4.8 kg) participated in the study. [Results] Spatiotemporal parameters (cadence, walking speed, stride length) were significantly different among the trials. Knee joint sagittal plane range of motion was not different with either kinesio taping application. Knee external flexion moment during the early stance phase decreased significantly with facilitation kinesio taping and increased with the inhibition kinesio taping. Knee external extension moment during the mid-stance phase increased with facilitation kinesio taping. Knee power parameters, eccentric activity in the rectus femoris during the pre-swing phase was significantly increased with inhibition kinesio taping application, while eccentric activity of the hamstrings during the terminal swing of gait was decreased. [Conclusion] These findings showed that facilitation kinesio taping application affected the terminal stance phase and that inhibition kinesio taping influenced the terminal swing phase compared with the no tape condition. PMID:26644651

  20. Activity Increase Despite Arthritis (AÏDA: design of a Phase II randomised controlled trial evaluating an active management booklet for hip and knee osteoarthritis [ISRCTN24554946

    Directory of Open Access Journals (Sweden)

    Edwards Rhiannon T

    2009-09-01

    Full Text Available Abstract Background Hip and knee osteoarthritis is a common cause of pain and disability, which can be improved by exercise interventions. However, regular exercise is uncommon in this group because the low physical activity level in the general population is probably reduced even further by pain related fear of movement. The best method of encouraging increased activity in this patient group is not known. A booklet has been developed for patients with hip or knee osteoarthritis. It focuses on changing disadvantageous beliefs and encouraging increased physical activity. Methods/Design This paper describes the design of a Phase II randomised controlled trial (RCT to test the effectiveness of this new booklet for patients with hip and knee osteoarthritis in influencing illness and treatment beliefs, and to assess the feasibility of conducting a larger definitive RCT in terms of health status and exercise behaviour. A computerised search of four general medical practice patients' record databases will identify patients older than 50 years of age who have consulted with hip or knee pain in the previous twelve months. A random sample of 120 will be invited to participate in the RCT comparing the new booklet with a control booklet, and we expect 100 to return final questionnaires. This trial will assess the feasibility of recruitment and randomisation, the suitability of the control intervention and outcome measurement tools, and will provide an estimate of effect size. Outcomes will include beliefs about hip and knee pain, beliefs about exercise, fear avoidance, level of physical activity, health status and health service costs. They will be measured at baseline, one month and three months. Discussion We discuss the merits of testing effectiveness in a phase II trial, in terms of intermediate outcome measures, whilst testing the processes for a larger definitive trial. We also discuss the advantages and disadvantages of testing the psychometric

  1. Total knee replacement for posttraumatic degenerative arthritis of the knee

    Institute of Scientific and Technical Information of China (English)

    WU Li-dong; XIONG Yan; YAN Shi-gui; YANG Quan-sen

    2005-01-01

    Objective: To evaluate the results of total knee arthroplasty (TKA) in patients with posttraumatic degenerative arthritis due to a previous fracture around the knee. Methods: We analyzed the results of 15 TKAs, performed from 1997 to 2003, in 15 patients with post-traumatic degenerative arthritis due to a previous fracture around knee. There were 3 women and 12 men with an average age of 58 years (range, 31-76 years). The time from fracture to arthroplasty averaged 8.2 years (range, 2-27 years). Internal fixation had previously been performed in 8 patients resulting in retained hardware. At the time of arthroplasty a femoral fracture malunion was present in two knees. Lateral retinacular release (4 knees), extensor mechanism realignment (1 knee) or medial collateral ligament reconstruction (1 knee) were needed at the time of arthroplasty. Results: Follow-up averaged 35 months (range, 12-73 months). No patient was lost for follow-up. According to the Knee Society Score scale, the mean preoperative knee score was 37 (range, 10-70) and functional score was 41 (range, 0-60). They were improved significantly to a mean of 84 (range, 10-100) and 76 (range, 20-100) points, respectively at the latest follow-up. The mean knee arc of motion were improved from 84° preoperation to 94° at the latest follow-up. Postoperative manipulation under anesthesia for poor motion was carried out in 4 knees. No knee had aseptic loosening that required subsequent revision. Two knees developed superficial infection and were treated with debridement. It subsequently recovered with the retention of components. Conclusions: Significant improvement in function and relief of pain has been achieved in patients with previous fractures undergoing subsequent TKA. However, this procedure is technically demanding and patients are at increased risk for restricted motion and need more care following TKA. This study suggests that the outcome of TKA may be improved further by making special efforts to

  2. Rough terrain motion planning for actively reconfigurable mobile robots

    Energy Technology Data Exchange (ETDEWEB)

    Brunner, Michael

    2015-02-05

    In the aftermath of the Tohoku earthquake and the nuclear meltdown at the power plant of Fukushima Daiichi in 2011, reconfigurable robots like the iRobot Packbot were deployed. Instead of humans, the robots were used to investigate contaminated areas. Other incidents are the two major earthquakes in Northern Italy in May 2012. Besides many casualties, a large number of historical buildings was severely damaged. Due to the imminent danger of collapse, it was too dangerous for rescue personnel to enter many of the buildings. Therefore, the sites were inspected by reconfigurable robots, which are able to traverse the rubble and debris of the partially destroyed buildings. This thesis develops a navigation system enabling wheeled and tracked robots to safely traverse rough terrain and challenging structures. It consists of a planning mechanism and a controller. The focus of this thesis, however, is on the contribution to motion planning. The planning scheme employs a hierarchical approach to motion planning for actively reconfigurable robots in rough environments. Using a map of the environment the algorithm estimates the traversability under the consideration of uncertainties. Based on this analysis, an initial path search determines an approximate solution with respect to the robot's operating limits.Subsequently, a detailed planning step refines the initial path where it is required. The refinement step considers the robot's actuators and stability in addition to the quantities of the first search. Determining the robot-terrain interaction is very important in rough terrain. This thesis presents two path refinement approaches: a deterministic and a randomized approach. The experimental evaluation investigates the separate components of the planning scheme, the robot-terrain interaction for instance.In simulation as well as in real world experiments the evaluation demonstrates the necessity of such a planning algorithm in rough terrain and it provides

  3. Rough terrain motion planning for actively reconfigurable mobile robots

    International Nuclear Information System (INIS)

    In the aftermath of the Tohoku earthquake and the nuclear meltdown at the power plant of Fukushima Daiichi in 2011, reconfigurable robots like the iRobot Packbot were deployed. Instead of humans, the robots were used to investigate contaminated areas. Other incidents are the two major earthquakes in Northern Italy in May 2012. Besides many casualties, a large number of historical buildings was severely damaged. Due to the imminent danger of collapse, it was too dangerous for rescue personnel to enter many of the buildings. Therefore, the sites were inspected by reconfigurable robots, which are able to traverse the rubble and debris of the partially destroyed buildings. This thesis develops a navigation system enabling wheeled and tracked robots to safely traverse rough terrain and challenging structures. It consists of a planning mechanism and a controller. The focus of this thesis, however, is on the contribution to motion planning. The planning scheme employs a hierarchical approach to motion planning for actively reconfigurable robots in rough environments. Using a map of the environment the algorithm estimates the traversability under the consideration of uncertainties. Based on this analysis, an initial path search determines an approximate solution with respect to the robot's operating limits.Subsequently, a detailed planning step refines the initial path where it is required. The refinement step considers the robot's actuators and stability in addition to the quantities of the first search. Determining the robot-terrain interaction is very important in rough terrain. This thesis presents two path refinement approaches: a deterministic and a randomized approach. The experimental evaluation investigates the separate components of the planning scheme, the robot-terrain interaction for instance.In simulation as well as in real world experiments the evaluation demonstrates the necessity of such a planning algorithm in rough terrain and it provides

  4. Effect of exercise therapy on neuromuscular activity and knee strength in female adolescents with patellofemoral pain

    DEFF Research Database (Denmark)

    Rathleff, Michael S.; Samani, Afshin; Olesen, Jens L.;

    2016-01-01

    BACKGROUND: Female adolescents with patellofemoral pain are characterized by altered neuromuscular knee control and reduced maximal quadriceps torque. The purpose of this study is to investigate whether exercise therapy and patient education are associated with larger improvements in neuromuscular...... knee control and maximal quadriceps torque compared with patient education alone. METHODS: This is an ancillary analysis of a cluster randomized controlled trial investigating the effect of patient education and exercise therapy on self-reported recovery in 121 adolescents with patellofemoral pain...... flexion/extension kinematics and maximal quadriceps torque. FINDINGS: There was an 8-15% greater decrease in the complexity of surface electromyography suggesting an improvement in neuromuscular knee control among those randomized to exercise therapy (0.08

  5. Viewing the motion of human body parts activates different regions of premotor, temporal, and parietal cortex.

    Science.gov (United States)

    Wheaton, Kylie J; Thompson, James C; Syngeniotis, Ari; Abbott, David F; Puce, Aina

    2004-05-01

    Activation of premotor and temporoparietal cortex occurs when we observe others movements, particularly relating to objects. Viewing the motion of different body parts without the context of an object has not been systematically evaluated. During a 3T fMRI study, 12 healthy subjects viewed human face, hand, and leg motion, which was not directed at or did not involve an object. Activation was identified relative to static images of the same human face, hand, and leg in both individual subject and group average data. Four clear activation foci emerged: (1) right MT/V5 activated to all forms of viewed motion; (2) right STS activated to face and leg motion; (3) ventral premotor cortex activated to face, hand, and leg motion in the right hemisphere and to leg motion in the left hemisphere; and (4) anterior intraparietal cortex (aIP) was active bilaterally to viewing hand motion and in the right hemisphere leg motion. In addition, in the group data, a somatotopic activation pattern for viewing face, hand, and leg motion occurred in right ventral premotor cortex. Activation patterns in STS and aIP were more complex--typically activation foci to viewing two types of human motion showed some overlap. Activation in individual subjects was similar; however, activation to hand motion also occurred in the STS with a variable location across subjects--explaining the lack of a clear activation focus in the group data. The data indicate that there are selective responses to viewing motion of different body parts in the human brain that are independent of object or tool use.

  6. Knee-Extension Training with a Single-Joint Hybrid Assistive Limb during the Early Postoperative Period after Total Knee Arthroplasty in a Patient with Osteoarthritis

    Science.gov (United States)

    Sugaya, Hisashi; Kubota, Shigeki; Onishi, Mio; Kanamori, Akihiro; Sankai, Yoshiyuki; Yamazaki, Masashi

    2016-01-01

    The knee range of motion is an important outcome of total knee arthroplasty (TKA). According to previous studies, the knee range of motion temporarily decreases for approximately 1 month after TKA due to postoperative pain and quadriceps dysfunction following surgical invasion into the knee extensor mechanism. We describe our experience with a knee-extension training program based on a single-joint hybrid assistive limb (HAL-SJ, Cyberdyne Inc., Tsukuba, Japan) during the acute recovery phase after TKA. HAL-SJ is a wearable robot suit that facilitates the voluntary control of knee joint motion. A 76-year-old man underwent HAL-SJ-based knee-extension training, which enabled him to perform knee function training during the acute phase after TKA without causing increased pain. Thus, he regained the ability to fully extend his knee postoperatively. HAL-SJ-based knee-extension training can be used as a novel post-TKA rehabilitation modality.

  7. Clinical predictors of elective total joint replacement in persons with end-stage knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Axe Michael J

    2010-05-01

    Full Text Available Abstract Background Arthritis is a leading cause of disability in the United States. Total knee arthroplasty (TKA has become the gold standard to manage the pain and disability associated with knee osteoarthritis (OA. Although more than 400 000 primary TKA surgeries are performed each year in the United States, not all individuals with knee OA elect to undergo the procedure. No clear consensus exists on criteria to determine who should undergo TKA. The purpose of this study was to determine which clinical factors will predict the decision to undergo TKA in individuals with end-stage knee OA. Knowledge of these factors will aid in clinical decision making for the timing of TKA. Methods Functional data from one hundred twenty persons with end-stage knee OA were obtained through a database. All of the individuals complained of knee pain during daily activities and had radiographic evidence of OA. Functional and clinical tests, collectively referred to as the Delaware Osteoarthritis Profile, were completed by a physical therapist. This profile consisted of measuring height, weight, quadriceps strength and active knee range of motion, while functional mobility was assessed using the Timed Up and Go (TUG test and the Stair Climbing Task (SCT. Self-perceived functional ability was measured using the activities of daily living subscale of the Knee Outcome Survey (KOS-ADLS. A logistic regression model was used to identify variables predictive of TKA use. Results Forty subjects (33% underwent TKA within two years of evaluation. These subjects were significantly older and had significantly slower TUG and SCT times (p 2 = 0.403. Conclusions Younger patients with full knee ROM who have a higher self-perception of function are less likely to undergo TKA. Physicians and clinicians should be aware that potentially modifiable factors, such as knee ROM can be addressed to potentially postpone the need for TKA.

  8. Knee Pain and the Weekend Warriors

    Medline Plus

    Full Text Available ... of that knee not being completely and totally flexible. But the knees bend right away. The next ... the past, but in other cases, they have led such active lives and they’re so full ...

  9. Implied motion because of instability in Hokusai Manga activates the human motion-sensitive extrastriate visual cortex: an fMRI study of the impact of visual art.

    Science.gov (United States)

    Osaka, Naoyuki; Matsuyoshi, Daisuke; Ikeda, Takashi; Osaka, Mariko

    2010-03-10

    The recent development of cognitive neuroscience has invited inference about the neurosensory events underlying the experience of visual arts involving implied motion. We report functional magnetic resonance imaging study demonstrating activation of the human extrastriate motion-sensitive cortex by static images showing implied motion because of instability. We used static line-drawing cartoons of humans by Hokusai Katsushika (called 'Hokusai Manga'), an outstanding Japanese cartoonist as well as famous Ukiyoe artist. We found 'Hokusai Manga' with implied motion by depicting human bodies that are engaged in challenging tonic posture significantly activated the motion-sensitive visual cortex including MT+ in the human extrastriate cortex, while an illustration that does not imply motion, for either humans or objects, did not activate these areas under the same tasks. We conclude that motion-sensitive extrastriate cortex would be a critical region for perception of implied motion in instability.

  10. Knee pain

    Science.gov (United States)

    ... time, overuse, or injury. Dislocation of the kneecap Fracture of the kneecap or other bones Iliotibial band syndrome . Injury to the thick band that runs from your hip to the outside of your knee. Pain in the front of your knee around ...

  11. Habitual Physical Activity After Total Knee Replacement : analysis in 830 patients and comparison with a sex-and age-matched normative population (vol 92, pg 1109, 2012)

    NARCIS (Netherlands)

    Kersten, Roel F. M. R.; Stevens, Martin; van Raay, Jos J. A. M.; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge

    2012-01-01

    Background. Previous studies on physical activity after total knee arthroplasty (TKA) concentrated mainly on a return to sports activities. Objective. The objectives of this study were to determine the habitual physical activity behavior of people who had undergone TKA (TKA group) 1 to 5 years after

  12. Focusing on Increasing Velocity during Heavy Resistance Knee Flexion Exercise Boosts Hamstring Muscle Activity in Chronic Stroke Patients

    Science.gov (United States)

    Jakobsen, Markus D.

    2016-01-01

    Background. Muscle strength is markedly reduced in stroke patients, which has negative implications for functional capacity and work ability. Different types of feedback during strength training exercises may alter neuromuscular activity and functional gains. Objective. To compare levels of muscle activity during conditions of blindfolding and intended high contraction speed with a normal condition of high-intensity knee flexions. Methods. Eighteen patients performed unilateral machine knee flexions with a 10-repetition maximum load. Surface electromyography (EMG) was recorded from the quadrics and hamstring muscles and normalized to maximal EMG (nEMG) of the nonparetic limb. Results. For the paretic leg, the speed condition showed higher values of muscle activity compared with the normal and blindfolded conditions for both biceps femoris and semitendinosus. Likewise, the speed condition showed higher co-contraction values compared with the normal and blindfolded conditions for the vastus lateralis. No differences were observed between exercise conditions for the nonparetic leg. Conclusion. Chronic stroke patients are capable of performing heavy resistance training with intended high speed of contraction. Focusing on speed during the concentric phase elicited higher levels of muscle activity of the hamstrings compared to normal and blindfolded conditions, which may have implications for regaining fast muscle strength in stroke survivors. PMID:27525118

  13. Analgesic Effect of High Intensity Laser Therapy in Knee Osteoarthritis

    OpenAIRE

    Štiglić-Rogoznica, Nives; Stamenković, Doris; Frlan-Vrgoč, Ljubinka; Avancini-Dobrović, Viviana; Schnurrer-Luke Vrbanić, Tea

    2011-01-01

    Knee osteoarthritis (KOA), the most common type of osteoarthritis (OA), is associated with pain and inflammation of the joint capsule, impaired muscular stabilization, reduced range of motion and functional disability. High-intensity laser therapy (HILT) involves higher-intensity laser radiation and causes minor and slow light absorption by chromophores. Light stimulation of the deep structures, due to high intensity laser therapy, activates cell metabolism through photochemical e...

  14. Relação entre altura da patela e amplitude de movimentos após a artroplastia total do joelho Relationship between patellar height and range of motion after total knee arthroplasty

    Directory of Open Access Journals (Sweden)

    Lúcio Honório de Carvalho Júnior

    2011-01-01

    Full Text Available OBJETIVO: Avaliar se após a artroplastia total do joelho existe correlação entre a altura da patela e a amplitude de movimento (ADM alcançada pelo paciente após seis meses de pós-operatório. MÉTODOS: Foram avaliados 45 pacientes submetidos a artroplastia total do joelho, todos com, no mínimo, 12 meses de pós-operatório, totalizando 54 joelhos. Sob fluoroscopia, todos os joelhos tiveram suas amplitudes de movimentos (ADM máximas e mínimas registradas, bem como a altura da patela pelo índice de Blackburne e Peel. Foram avaliadas as duas correlações possíveis: relação entre altura da patela e ADM e altura da patela e a variação de ADM entre o pré e o pós-operatório. RESULTADOS: Foi observada correlação entre altura da patela e ADM no pós-operatório (p = 0,04. Não foi observada correlação entre altura da patela e variação de ADM (p = 0,182. CONCLUSÃO: No pós-operatório da artroplastia total do joelho, quanto mais baixa a patela, pior a ADM.OBJECTIVE: To evaluate whether, after total knee arthroplasty, there is any correlation between patellar height and range of motion (ROM achieved by patients six months after the operation. METHODS: Forty-five patients who underwent total knee arthroplasty were assessed at least 12 months after the operation (total of 54 knees. The maximum and minimum ROM of all the knees was recorded under fluoroscopy, along with patellar height according to the Blackburne and Peel ratio. Two possible correlations were evaluated: patellar height and ROM; and patellar height and ROM variation from before to after the operation. RESULTS: A correlation was found between patellar height and postoperative ROM (p = 0.04. There was no correlation between patellar height and ROM variation (p = 0.182. CONCLUSION: After total knee arthroplasty, the lower the patella is, the worse the ROM is.

  15. Does Physical Activity Increase After Total Hip or Knee Arthroplasty for Osteoarthritis? A Systematic Review.

    Science.gov (United States)

    Arnold, John B; Walters, Julie L; Ferrar, Katia E

    2016-06-01

    Study Design Systematic review. Background Despite improvements in self-reported symptoms and perceived functional ability after total hip arthroplasty (THA) and total knee arthroplasty (TKA), it is unclear whether changes in objectively measured physical activity (PA) occur after surgery. Objective To determine if objectively measured PA increases after THA and TKA in adults with osteoarthritis. Methods Five electronic databases were searched from inception to March 3, 2015. All study designs objectively measuring PA before and after THA or TKA were eligible, including randomized controlled trials, cohort studies, and case-control studies. Two reviewers independently screened abstracts and full texts and extracted study demographic, PA, and clinical outcome data. Standardized mean differences (SMDs) and 95% confidence intervals were calculated for accelerometer- and pedometer-derived estimates of PA. Risk of methodological bias was assessed with Critical Appraisal Skills Programme checklists. Results Eight studies with a total of 373 participants (238 TKA, 135 THA) were included. Findings were mixed regarding improvement in objectively measured PA at 6 months after THA (SMDs, -0.20 to 1.80) and TKA (SMDs, -0.36 to 0.63). Larger improvements from 2 studies at 1 year postsurgery were generally observed after THA (SMDs, 0.39 to 0.79) and TKA (SMDs, 0.10 to 0.85). However, at 1 year, PA levels were still considerably lower than those of healthy controls (THA SMDs, -0.25 to -0.77; TKA SMDs, -1.46 to -1.80). Risk-of-bias scores ranged from 3 to 9 out of 11 (27%-82%) for cohort studies, and from 3 to 8 out of 10 (30%-80%) for case-control studies. Conclusion The best available evidence indicates negligible changes in PA at 6 months after THA or TKA, with limited evidence for larger changes at 1 year after surgery. In the 4 studies that reported control-group data, postoperative PA levels were still considerably less than those of healthy controls. Improved perioperative

  16. Quantitative MR characterization of disease activity in the knee in children with juvenile idiopathic arthritis: a longitudinal pilot study

    Energy Technology Data Exchange (ETDEWEB)

    Workie, Dagnachew W. [University of Cincinnati, Department of Physics, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Cincinnati, OH (United States); Graham, T.B. [Cincinnati Children' s Hospital Medical Center, Division of Rheumatology, Cincinnati, OH (United States); Laor, Tal; Racadio, Judy M. [Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States); Rajagopal, Akila; O' Brien, Kendall J.; Bommer, Wendy A. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Cincinnati, OH (United States); Shire, Norah J. [University of Cincinnati, Division of Epidemiology and Biostatistics, Cincinnati, OH (United States); University of Cincinnati, Division of Digestive Diseases, Cincinnati, OH (United States); Dardzinski, Bernard J. [Cincinnati Children' s Hospital Medical Center, Imaging Research Center, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Pediatrics, Cincinnati, OH (United States); Cincinnati Children' s Hospital Medical Center, Department of Radiology, Cincinnati, OH (United States)

    2007-06-15

    The development of a quantifiable and noninvasive method of monitoring disease activity and response to therapy is vital for arthritis management. The purpose of this study was to investigate the utility of quantitative dynamic contrast-enhanced MRI (DCE-MRI) based on pharmacokinetic (PK) modeling to evaluate disease activity in the knee and correlate the results with the clinical assessment in children with juvenile idiopathic arthritis (JIA). A group of 17 children with JIA underwent longitudinal clinical and laboratory assessment and DCE-MRI of the knee at enrollment, 3 months, and 12 months. A PK model was employed using MRI signal enhancement data to give three parameters, K{sup trans} ' (min{sup -1}), k{sub ep} (min{sup -1}), and V{sub p} ' and to calculate synovial volume. The PK parameters, synovial volumes, and clinical and laboratory assessments in most children were significantly decreased (P < 0.05) at 12 months when compared to the enrollment values. There was excellent correlation between the PK and synovial volume and the clinical and laboratory assessments. Differences in MR and clinical parameter values in individual subjects illustrate persistent synovitis when in clinical remission. A decrease in PK parameter values obtained from DCE-MRI in children with JIA likely reflects diminution of disease activity. This technique may be used as an objective follow-up measure of therapeutic efficacy in patients with JIA. MR imaging can detect persistent synovitis in patients considered to be in clinical remission. (orig.)

  17. Will 'Unloading' Shoes Help Your Arthritic Knees?

    Science.gov (United States)

    ... anti-inflammatory medications may also help, as might physical therapy designed to improve flexibility and motion range. In severe cases, patients undergo invasive knee surgery ranging from joint-lining removal to partial or ...

  18. Measurement of perioperative flexion-extension mechanics of the knee joint.

    Science.gov (United States)

    Giori, N J; Giori, K L; Woolson, S T; Goodman, S B; Lannin, J V; Schurman, D J

    2001-10-01

    Perioperative knee mechanics currently are evaluated Perioperative knee mechanics currently are evaluated by measuring range of motion. This is an incomplete measurement, however, because the torque applied to achieve the motion is not measured. We hypothesized that a custom goniometer and force transducer could measure the torque required to passively flex a knee through its full range of motion. This measurement was done in the operating room immediately before and after surgery in 20 knees having total knee arthroplasty and 9 having surgery on another limb. Surgery changed the mechanics of 8 knees, whereas unoperated knees remained unchanged. This measurement technique is safe, easy, and repeatable. It improves on the current standard of perioperative knee measurement and can be applied to investigate the effects of surgery and rehabilitation on ultimate knee motion.

  19. 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.

  20. 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.

  1. Active Brownian motion of an asymmetric rigid particle

    CERN Document Server

    Mammadov, Gulmammad

    2012-01-01

    Individual movements of a rod-like self-propelled particle on a flat substrate are quantified. Biological systems that fit into this description may be the Gram-negative delta-proteobacterium Myxococcus xanthus, Gram-negative bacterium Escherichia coli, and Mitochondria. There are also non-living analogues such as vibrated polar granulates and self-driven anisotropic colloidal particles. For that we study the Brownian motion of an asymmetric rod-like rigid particle self-propelled at a fixed speed along its long axis in two dimensions. The motion of such a particle in a uniform external potential field is also considered. The theoretical model presented here is anticipated to better describe individual cell motion as well as intracellular transport in 2D than previous models.

  2. Thermally activated dislocation motion including inertial effects in solid solutions

    International Nuclear Information System (INIS)

    Dislocation motion through an array of obstacles is considered in terms of the potential energy of the dislocation as it moves through the array. The obstacles form a series of potential wells and barriers which can trap the dislocations. The effect of thermal fluctuations and of a viscous drag on the motion of the dislocation is investigated by analogy with Brownian motion in a field of force. The rate of escape of a trapped dislocation is found to depend on the damping coefficient only for a large viscous drag. The probability that a dislocation will be trapped by a well or barrier is found to depend on the damping coefficient for a small viscous drag. This inertial effect determines how far a dislocation will travel after breaking away from an obstacle

  3. Severe Heterotopic Ossification following Total Knee Replacement

    OpenAIRE

    Dodds, Alexander L.; Keene, Gregory C. R.

    2014-01-01

    Although the incidence of minor heterotopic ossification is probably higher than what is usually expected, severe heterotopic ossification (HO) is an extremely rare event following total knee replacement surgery. We present the case of a 66-year-old woman who initially had achieved an excellent range of motion following bilateral uncemented rotating platform total knee replacement, before presenting with pain and loss of range of motion at 2 months after surgery. Severe HO was diagnosed on X-...

  4. Effect of anterior cruciate ligament reconstruction on biomechanical features of knee in level walking: a meta-analysis

    Institute of Scientific and Technical Information of China (English)

    SHI Dong-liang; WANG Yu-bin; AI Zi-sheng

    2010-01-01

    Background The anterior cruciate ligament (ACL) is one of the most commonly injured knee ligaments. Even following ACL reconstruction, significant articular cartilage degeneration can be observed and most patients suffer from premature osteoarthritis. Articular cartilage degeneration and osteoarthritis development after ACL injury are regarded as progressive process that are affected by cyclic loading during frequently performed low-intensity daily activities. The purpose of this study was to perform a meta analysis on studies assessing the effects of ACL reconstruction on kinematics, kinetics and proprioception of knee during level walking.Methods This meta analysis was conducted according to the methodological guidelines outlined by the Cochrane Collaboration. An electronic search of the literature was performed and all trials published between January 1966 and July 2010 comparing gait and proprioception of a reconstructed-ACL group with an intact-ACL group were pooled for this review. Thirteen studies were included in the final meta analysis.Results There was no significant difference in step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion between the reconstructed-ACL group and the intact-ACL group (P >0.05). However, there was a significant difference in peak knee flexion angle, maximum angular knee flexion excursion during stance, peak knee flexion moment during walking and maximum external tibial rotation angle throughout the gait cycle between the reconstructed-ACL group and the intact-ACL group (P <0.05).Conclusions Step length, walking speed, maximum knee flexion angle during loading response, joint position sense and threshold to detect passive motion usually observed with ACL deficiency were restored after the ACL reconstruction and rehabilitation, but no significant improvements were observed for peak knee flexion angle, maximum angular knee flexion excursion

  5. Total Knee Arthroplasty Using a Posterior Cruciate Ligament Sacrificing Medial Pivot Knee: Minimum 5-year Follow-up Results

    OpenAIRE

    Youm, Yoon-Seok; Cho, Sung-Do; Lee, Seon-Ho; Cho, Hye-Yong

    2014-01-01

    Purpose To evaluate minimum 5-year follow-up clinical and radiological results of total knee arthroplasty (TKA) using a posterior cruciate ligament sacrificing (PS), non-substituting Advance Medial Pivot Knee. Materials and Methods One hundred and twenty knees in 80 patients who could be followed up for more than 5 years after TKA using the PS Advance Medial Pivot Knee were evaluated retrospectively. The evaluations included the preoperative and postoperative range of motion (ROM), tibiofemor...

  6. Generalized analysis of thermally activated domain-wall motion in Co/Pt multilayers

    International Nuclear Information System (INIS)

    Thermally activated domain-wall (DW) motion driven by magnetic field and electric current is investigated experimentally in out-of-plane magnetized Pt(Co/Pt)3 multilayers. We directly extract the thermal activation energy barrier for DW motion and observe the dynamic regimes of creep, depinning, and viscous flow. Further analysis reveals that the activation energy must be corrected with a factor dependent on the Curie temperature, and we derive a generalized Arrhenius-like equation governing thermally activated motion. By using this generalized equation, we quantify the efficiency of current-induced spin torque in assisting DW motion. Current produces no effect aside from Joule heating in the multilayer with 7-Å thick Co layers, whereas it generates a finite spin torque on DWs in the multilayer with atomically thin 3-Å Co layers. These findings suggest that conventional spin-transfer torques from in-plane spin-polarized current do not drive DWs in ultrathin Co/Pt multilayers. - Highlights: • Thermally activated domain-wall motion is investigated in Pt(Co/Pt)3 multilayers. • The activation energy for wall motion is directly extracted, revealing distinct dynamic regimes. • A generalized Arrhenius-like equation governing thermally activated motion is derived. • Conventional spin-transfer torques do not drive domain walls in ultrathin Co/Pt multilayers

  7. The effects of Juchumseogi and Juchumseo Jireugi motions of taekwondo on muscle activation of paraspinal muscles.

    Science.gov (United States)

    Baek, Jongmyeng; Lee, Jaeseok; Kim, Jonghyun; Kim, Jeonghun; Han, Dongwook; Byun, Sunghak

    2015-09-01

    [Purpose] The purpose of this study is to examine the effects of Juchumseogi and Juchumseo Jireugi motions on muscle activation of the paraspinal muscles. [Subjects] The subjects of this study were 20 healthy male students who listened to an explanation of the study methods and the purpose of the experiment, and agreed to participate in the study. [Methods] Muscle activation measurements of the paraspinal muscles at C3, T7, and L3 were taken while standing still and while performing Juchumseogi and Juchumseo Jireugi movements. The Juchumseogi and Juchumseo Jireugi motions were performed 3 times, and its mean value was used for analysis. [Results] The right and left muscle activation of paraspinal muscles induced by Juchumseogi and Juchumseo Jireugi motions in C3 and T7 were significantly higher than those induced by just standing. Muscle activation of paraspinal muscles induced by Juchumseo Jireugi motions in C3, T7, and L3 were significantly higher than those induced by Juchumseogi alone. The right and left muscle activation of paraspinal muscles induced by Juchumseo Jireugi motion in C3, T7, and L3 were significantly higher than those induced by standing and Juchumseogi alone. [Conclusion] This study demonstrated that Juchumseogi and Juchumseo Jireugi motions of Taekwondo could increase muscle activation of paraspinal muscles, and Juchumseo Jireugi motions were more effective for enhancing muscle activation of paraspinal muscles.

  8. Knee Injuries and Disorders

    Science.gov (United States)

    Your knee joint is made up of bone, cartilage, ligaments and fluid. Muscles and tendons help the knee joint move. When any of these structures is hurt or diseased, you have knee problems. Knee problems can cause pain and difficulty ...

  9. High knee valgus in female subjects does not yield higher knee translations during drop landings: a biplane fluoroscopic study.

    Science.gov (United States)

    Torry, Michael R; Shelburne, Kevin B; Myers, Casey; Giphart, J Erik; Pennington, W Wesley; Krong, Jacob P; Peterson, Daniel S; Steadman, J Richard; Woo, Savio L-Y

    2013-02-01

    The goal of this study was to determine the effects of peak knee valgus angle and peak knee abductor moment on the anterior, medial, and lateral tibial translations (ATT, MTT, LTT) in the "at risk" female knee during drop landing. Fifteen female subjects performed drop landings from 40 cm. Three-dimension knee motion was simultaneously recorded using a high speed, biplane fluoroscopy system, and a video-based motion analysis system. Valgus knee angles and knee abduction moments were stratified into low, intermediate, and high groups and peak ATT, MTT, and LTT were compared between these groups with ANOVA (α = 0.05). Significant differences were observed between stratified groups in peak knee valgus angle (p < 0.0001) and peak knee abduction moment (p < 0.0001). However, no corresponding differences in peak ATT, LTT, and MTT between groups exhibiting low to high-peak knee valgus angles (ATT: p = 0.80; LTT: p = 0.25; MTT: p = 0.72); or, in peak ATT (p = 0.61), LTT (p = 0.26) and MTT (p = 0.96) translations when stratified according to low to high knee abduction moments, were found. We conclude that the healthy female knee is tightly regulated with regard to translations even when motion analysis derived knee valgus angles and abduction moments are high.

  10. Active damping of vibrations in high-precision motion systems

    OpenAIRE

    Babakhani, Bayan

    2012-01-01

    Technology advancements feed the need for ever faster and more accurate industrial machines. Vibration is a significant source of inaccuracy of such machines. A light-weight design in favor of the speed, and avoiding the use of energy-dissipating materials from the structure to omit any source of inaccuracy, contribute to a low structural damping. The goal of this research is to investigate the addition of damping to the rotational vibration mode of a linearly actuated motion system to • achi...

  11. Multiple Ligament Knee Injury: Complications

    OpenAIRE

    Manske, Robert C; Hosseinzadeh, Pooya; Giangarra, Charles E.

    2008-01-01

    Non-operative and operative complications are common following multiple ligament knee injuries. This article will describe common complications seen by the surgeon and physical therapist following this complex injury. Complications include fractures, infections, vascular and neurologic complications following injury and surgery, compartment syndrome, complex regional pain syndrome, deep venous thrombosis, loss of motion and persistent laxity issues. A brief description of these complications ...

  12. Localized, Non-Harmonic Active Flap Motions for Low Frequency In-Plane Rotor Noise Reduction

    Science.gov (United States)

    Sim, Ben W.; Potsdam, Mark; Kitaplioglu, Cahit; LeMasurier, Philip; Lorber, Peter; Andrews, Joseph

    2012-01-01

    A first-of-its-kind demonstration of the use of localized, non-harmonic active flap motions, for suppressing low frequency, in-plane rotor noise, is reported in this paper. Operational feasibility is verified via testing of the full-scale AATD/Sikorsky/UTRC active flap demonstration rotor in the NFAC's 40- by 80-Foot anechoic wind tunnel. Effectiveness of using localized, non-harmonic active flap motions are compared to conventional four-per-rev harmonic flap motions, and also active flap motions derived from closed-loop acoustics implementations. All three approaches resulted in approximately the same noise reductions over an in-plane three-by-three microphone array installed forward and near in-plane of the rotor in the nearfield. It is also reported that using an active flap in this localized, non-harmonic manner, resulted in no more that 2% rotor performance penalty, but had the tendency to incur higher hub vibration levels.

  13. Objective clinical performance outcome of total knee prostheses. A study of mobile bearing knees using fluoroscopy, electromyography and roentgenstereophotogrammetry

    NARCIS (Netherlands)

    Garling, Eric Harald

    2008-01-01

    The aim of the thesis was to to assess with accurate and objective methods the function and fixation of total knee prostheses with special emphasis on mobile bearing total knee designs. The mobile bearing of a rotating platform design showed limited motion or no motion during a step-up task thereby

  14. Primary osteosynthesis augmented with autologous bone graft with total knee arthroplasty in patients with stress fractures of medial femoral condyle with knee osteoarthritis: a cost effective approach

    Directory of Open Access Journals (Sweden)

    Vikram Indrajit Shah

    2016-06-01

    Results: Mean follow-up was 7.0 years. All patients showed statistically significant improvement in their WOMAC total scores (p <0.05. Stress fractures united with good knee alignment. All patients had recovered full range of motion with no pain at the time of final follow-up. No adverse events were noted in any of the patient treated. Conclusions: The present approach is a successful procedure for the elderly population with an arthritic knee with stress fracture of medial femoral condyle. Return to pre-morbid level of functional activity occurs very swiftly. [Int J Res Med Sci 2016; 4(6.000: 2408-2412

  15. Knee joint laxity and neuromuscular characteristics of male and female soccer and basketball players.

    Science.gov (United States)

    Rozzi, S L; Lephart, S M; Gear, W S; Fu, F H

    1999-01-01

    Anterior cruciate ligament injuries are occurring at a higher rate in female athletes compared with their male counterparts. Research in the area of anterior cruciate ligament injury has increasingly focused on the role of joint proprioception and muscle activity in promoting knee joint stability. We measured knee joint laxity, joint kinesthesia, lower extremity balance, the amount of time required to generate peak torque of the knee flexor and extensor musculature, and electromyographically assessed muscle activity in 34 healthy, collegiate-level athletes (average age, 19.6 +/- 1.5 years) who played soccer or basketball or both. Independent t-tests were used to determine significant sex differences. Results revealed that women inherently possess significantly greater knee joint laxity values, demonstrate a significantly longer time to detect the knee joint motion moving into extension, possess significantly superior single-legged balance ability, and produce significantly greater electromyographic peak amplitude and area of the lateral hamstring muscle subsequent to landing a jump. The excessive joint laxity of women appears to contribute to diminished joint proprioception, rendering the knee less sensitive to potentially damaging forces and possibly at risk for injury. Unable to rely on ligamentous structures, healthy female athletes appear to have adopted compensatory mechanisms of increased hamstring activity to achieve functional joint stabilization.

  16. Arthroscopy of the knee without pathological findings.

    Science.gov (United States)

    Schlepckow, P; Weber, M; Hempel, K

    1994-01-01

    From 1983 to 1990, 82 knee arthroscopies (8.2%) carried out in our patients found nothing pathological. Sixty-four percent of these patients were active in sports, but trauma was noted in 32% of the cases only. Football and other ball games, skiing, and track and field athletics were the main causes. Twenty-six percent of the patients had undergone previous surgery in the affected knee. At a mean of 4.6 years postoperatively, clinical and radiological re-assessment was conducted so as to compare our pre- and intraoperative findings with the further course of events. We found that 48.2% of the patients were symptom-free after the diagnostic arthroscopy, 37.5% had persistent discomfort and 14.3% had a recurrence of discomfort after 6 months to 2 years. The objective measurement score (Zarins Rowe score), at 47.5 out of 50 points, was better than the subjective score, at 40 out of 50 points. Our diagnoses had to be changed retrospectively: meniscal lesions were diagnosed too frequently, while chondropathia patellae and instability were often missed. Additionally, complaints could be related to abnormal axis, limited range of motion of the hip or knee, leg length inequality and hypermobility. Being unable to verify a presumed intra-articular lesion arthroscopically is frustrating for both doctor and patient. Our data suggest that meniscal signs should be looked at more critically and emphasise the need for a complete evaluation of the whole locomotor system.

  17. Influence of Active Manipulation of an Object on Visual Motion Perception

    Directory of Open Access Journals (Sweden)

    Kazumichi Matsumiya

    2011-10-01

    Full Text Available When we manipulate an object by hand, the movements of the object are produced with the visual and haptic movements of our hands. Studies of multimodal perception show the interaction between touch and vision in visual motion perception(1,2. The influence of touch on visual motion perception is shown by the fact that adaptation to tactile motion across the observer's hand induces a visual motion aftereffect, which is a visual illusion in which exposure to a moving visual pattern makes a subsequently viewed stationary visual pattern appear to move in the opposite direction(2. This visuo-tactile interaction plays an important role in skillful manipulation(3. However, it is not clear how haptic information influences visual motion perception. We measured the strength of a visual motion aftereffect after visuo-haptic adaptation to a windmill rotated by observers. We found that the visual motion aftereffect was enhanced when observers actively rotated the windmill. The motion aftereffect was not enhanced when the observer's hand was passively moved. Our results suggest the presence of a visual motion system that is linked to the intended haptic movements.

  18. Physical Activity Recognition Based on Motion in Images Acquired by a Wearable Camera.

    Science.gov (United States)

    Zhang, Hong; Li, Lu; Jia, Wenyan; Fernstrom, John D; Sclabassi, Robert J; Mao, Zhi-Hong; Sun, Mingui

    2011-06-01

    A new technique to extract and evaluate physical activity patterns from image sequences captured by a wearable camera is presented in this paper. Unlike standard activity recognition schemes, the video data captured by our device do not include the wearer him/herself. The physical activity of the wearer, such as walking or exercising, is analyzed indirectly through the camera motion extracted from the acquired video frames. Two key tasks, pixel correspondence identification and motion feature extraction, are studied to recognize activity patterns. We utilize a multiscale approach to identify pixel correspondences. When compared with the existing methods such as the Good Features detector and the Speed-up Robust Feature (SURF) detector, our technique is more accurate and computationally efficient. Once the pixel correspondences are determined which define representative motion vectors, we build a set of activity pattern features based on motion statistics in each frame. Finally, the physical activity of the person wearing a camera is determined according to the global motion distribution in the video. Our algorithms are tested using different machine learning techniques such as the K-Nearest Neighbor (KNN), Naive Bayesian and Support Vector Machine (SVM). The results show that many types of physical activities can be recognized from field acquired real-world video. Our results also indicate that, with a design of specific motion features in the input vectors, different classifiers can be used successfully with similar performances.

  19. PENINGKATAN PRODUKTIVITAS DAN EFISIENSI BIAYA MELALUI INTEGRASI TIME & MOTION STUDY DAN ACTIVITY-BASED COSTING

    OpenAIRE

    Monika Kussetya Ciptani

    2001-01-01

    Organizations today have many activities that increase continuously. There are some activities that companies have to do to meet customers' need. Some companies try to increase efficiency in performing their activities and try to measure activities they do although the difficulties in measuring each activities are very high. In this case, time & motion study method is one of the solutions to help the company measuring their activity. The company's activity consume time and resources, that...

  20. Between-day repeatability of knee kinematics during functional tasks recorded using flexible electrogoniometry.

    Science.gov (United States)

    van der Linden, M L; Rowe, P J; Nutton, R W

    2008-08-01

    The objective of this study was to assess the between-day repeatability of knee kinematics during activities of daily living recorded by electrogoniometry. One rater assessed the peak knee angles and knee excursion of 15 subjects during 13 activities twice with an average of 22 days (range 5-31) between the two assessments. The 15 subjects included four patients one year after total knee replacement (TKR) surgery, five patients before TKR surgery and six age-matched controls. Intra-class correlation coefficients and Bland and Altman coefficient of repeatability were derived to analyse the results. Only the most affected leg of the patients and the right leg of the controls were used for analysis. Different measures of repeatability showed different results. Intra-class correlation coefficients were higher than 0.75 for peak values of all functions except sitting down and rising from a standard chair. However, coefficients of repeatability ranged from 5.6 degrees for the loading response in level walking to 39.8 degrees for stepping out of a bath. Both of these values are higher than clinically significant changes seen after total knee surgery. It was concluded that for a single assessment on individual patients, the functional knee motion as performed in this study did not have sufficient repeatability. However, if the measurements are used to assess the average changes before and after surgery in a group of patients, the assessment of knee motion during activities such as level walking, and slope and stair ascending and descending were found to be sufficiently repeatable. PMID:18329271

  1. The association between symptoms, pain coping strategies, and physical activity among people with symptomatic knee and hip osteoarthritis

    Directory of Open Access Journals (Sweden)

    Susan L Murphy

    2012-09-01

    Full Text Available Effective use of coping strategies by people with chronic pain conditions is associated with better functioning and adjustment to chronic disease. Although the effects of coping on pain have been well studied, less is known about how specific coping strategies relate to actual physical activity patterns in daily life. The purpose of this study was to evaluate how different coping strategies relate to symptoms and physical activity patterns in a sample of adults with knee and hip osteoarthritis (N = 44. Physical activity was assessed by wrist-worn accelerometry; coping strategy use was assessed by the Chronic Pain Coping Inventory. We hypothesized that the use of coping strategies that reflect approach behaviors (e.g., Task Persistence, would be associated with higher average levels of physical activity, whereas avoidance coping behaviors (e.g., Resting, Asking for Assistance, Guarding and Pacing would be associated with lower average levels of physical activity. We also evaluated whether coping strategies moderated the association between momentary symptoms (pain and fatigue and activity. We hypothesized that higher levels of approach coping would be associated with a weaker association between symptoms and activity compared to lower levels of this type of coping. Multilevel modeling was used to analyze the momentary association between coping and physical activity. We found that higher body mass index, fatigue, and the use of Guarding were significantly related to lower activity levels, whereas Asking for Assistance was significantly related to higher activity levels. Only Resting moderated the association between pain and activity. Guarding, Resting, Task Persistence, and Pacing moderated the association between fatigue and activity. This study provides an initial understanding of how people with osteoarthritis cope with symptoms as they engage in daily life activities using ecological momentary assessment and objective physical activity

  2. Contrast-enhanced MRI of the knee in children unaffected by clinical arthritis compared to clinically active juvenile idiopathic arthritis patients

    Energy Technology Data Exchange (ETDEWEB)

    Nusman, Charlotte M.; Hemke, Robert [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Benninga, Marc A.; Kindermann, Angelika [University of Amsterdam, Department of Pediatric Gastroenterology, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Schonenberg-Meinema, Dieneke; Berg, J.M. van den; Kuijpers, Taco W. [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Rossum, Marion A.J. van [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Reade, Department of Pediatric Rheumatology, Amsterdam (Netherlands); Maas, Mario [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands)

    2016-04-15

    To evaluate enhancing synovial thickness upon contrast-enhanced magnetic resonance imaging (MRI) of the knee in children unaffected by clinical arthritis compared with clinically active juvenile idiopathic arthritis (JIA) patients. A secondary objective was optimization of the scoring method based on maximizing differences on MRI between these groups. Twenty-five children without history of joint complaints nor any clinical signs of joint inflammation were age/sex-matched with 25 clinically active JIA patients with arthritis of at least one knee. Two trained radiologists, blinded for clinical status, independently evaluated location and extent of enhancing synovial thickness with the validated Juvenile Arthritis MRI Scoring system (JAMRIS) on contrast-enhanced axial fat-saturated T1-weighted MRI of the knee. Enhancing synovium (≥2 mm) was present in 13 (52 %) unaffected children. Using the total JAMRIS score for synovial thickening, no significant difference was found between unaffected children and active JIA patients (p = 0.091). Additional weighting of synovial thickening at the JIA-specific locations enabled more sensitive discrimination (p = 0.011). Mild synovial thickening is commonly present in the knee of children unaffected by clinical arthritis. The infrapatellar and cruciate ligament synovial involvement were specific for JIA, which - in a revised JAMRIS - increases the ability to discriminate between JIA and unaffected children. (orig.)

  3. Contrast-enhanced MRI of the knee in children unaffected by clinical arthritis compared to clinically active juvenile idiopathic arthritis patients

    International Nuclear Information System (INIS)

    To evaluate enhancing synovial thickness upon contrast-enhanced magnetic resonance imaging (MRI) of the knee in children unaffected by clinical arthritis compared with clinically active juvenile idiopathic arthritis (JIA) patients. A secondary objective was optimization of the scoring method based on maximizing differences on MRI between these groups. Twenty-five children without history of joint complaints nor any clinical signs of joint inflammation were age/sex-matched with 25 clinically active JIA patients with arthritis of at least one knee. Two trained radiologists, blinded for clinical status, independently evaluated location and extent of enhancing synovial thickness with the validated Juvenile Arthritis MRI Scoring system (JAMRIS) on contrast-enhanced axial fat-saturated T1-weighted MRI of the knee. Enhancing synovium (≥2 mm) was present in 13 (52 %) unaffected children. Using the total JAMRIS score for synovial thickening, no significant difference was found between unaffected children and active JIA patients (p = 0.091). Additional weighting of synovial thickening at the JIA-specific locations enabled more sensitive discrimination (p = 0.011). Mild synovial thickening is commonly present in the knee of children unaffected by clinical arthritis. The infrapatellar and cruciate ligament synovial involvement were specific for JIA, which - in a revised JAMRIS - increases the ability to discriminate between JIA and unaffected children. (orig.)

  4. The biomechanics and energetics of human running using an elastic knee exoskeleton.

    Science.gov (United States)

    Elliott, Grant; Sawicki, Gregory S; Marecki, Andrew; Herr, Hugh

    2013-06-01

    While the effects of series compliance on running biomechanics are well documented, the effects of parallel compliance are known only for the simpler case of hopping. As many practical exoskeletal and orthotic designs act in parallel with the leg, it is desirable to understand the effects of such an intervention. Spring-like forces offer a natural choice of perturbation for running, as they are both biologically motivated and energetically inexpensive to implement. To this end, we investigate the hypothesis that the addition of an external elastic element at the knee during the stance phase of running results in a reduction in knee extensor activation so that total joint quasi-stiffness is maintained. An exoskeletal knee brace consisting of an elastic element engaged by a clutch is used to provide this stance phase extensor torque. Motion capture of five subjects is used to investigate the consequences of running with this device. No significant change in leg stiffness or total knee stiffness is observed due to the activation of the clutched parallel knee spring. However, this pilot data suggests differing responses between casual runners and competitive long-distance runners, whose total knee torque is increased by the device. Such a relationship between past training and effective utilization of an external force is suggestive of limitations on the applicability of assistive devices. PMID:24187237

  5. Active motions of Brownian particles in a generalized energy-depot model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yong; Koo Kim, Chul [Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749 (Korea, Republic of); Lee, Kong-Ju-Bock [Department of Physics, Ewha Woman' s University, Seoul 120-750 (Korea, Republic of)], E-mail: xyzhang@phya.yonsei.ac.kr, E-mail: ckkim@yonsei.ac.kr, E-mail: kjblee@ewha.ac.kr

    2008-10-15

    We present a generalized energy-depot model in which the rate of conversion of the internal energy into motion can be dependent on the position and velocity of a particle. When the conversion rate is a general function of the velocity, the active particle exhibits diverse patterns of motion, including a braking mechanism and a stepping motion. The phase trajectories of the motion are investigated in a systematic way. With a particular form of the conversion rate dependent on the position and velocity, the particle shows a spontaneous oscillation characterizing a negative stiffness. These types of active behaviors are compared with similar phenomena observed in biology, such as the stepping motion of molecular motors and amplification in the hearing mechanism. Hence, our model can provide a generic understanding of the active motion related to the energy conversion and also a new control mechanism for nano-robots. We also investigate the effect of noise, especially on the stepping motion, and observe random walk-like behavior as expected.

  6. The visual perception of natural motion: abnormal task-related neural activity in DYT1 dystonia.

    Science.gov (United States)

    Sako, Wataru; Fujita, Koji; Vo, An; Rucker, Janet C; Rizzo, John-Ross; Niethammer, Martin; Carbon, Maren; Bressman, Susan B; Uluğ, Aziz M; Eidelberg, David

    2015-12-01

    Although primary dystonia is defined by its characteristic motor manifestations, non-motor signs and symptoms have increasingly been recognized in this disorder. Recent neuroimaging studies have related the motor features of primary dystonia to connectivity changes in cerebello-thalamo-cortical pathways. It is not known, however, whether the non-motor manifestations of the disorder are associated with similar circuit abnormalities. To explore this possibility, we used functional magnetic resonance imaging to study primary dystonia and healthy volunteer subjects while they performed a motion perception task in which elliptical target trajectories were visually tracked on a computer screen. Prior functional magnetic resonance imaging studies of healthy subjects performing this task have revealed selective activation of motor regions during the perception of 'natural' versus 'unnatural' motion (defined respectively as trajectories with kinematic properties that either comply with or violate the two-thirds power law of motion). Several regions with significant connectivity changes in primary dystonia were situated in proximity to normal motion perception pathways, suggesting that abnormalities of these circuits may also be present in this disorder. To determine whether activation responses to natural versus unnatural motion in primary dystonia differ from normal, we used functional magnetic resonance imaging to study 10 DYT1 dystonia and 10 healthy control subjects at rest and during the perception of 'natural' and 'unnatural' motion. Both groups exhibited significant activation changes across perceptual conditions in the cerebellum, pons, and subthalamic nucleus. The two groups differed, however, in their responses to 'natural' versus 'unnatural' motion in these regions. In healthy subjects, regional activation was greater during the perception of natural (versus unnatural) motion (P perception of unnatural (versus natural) motion (P perception is disrupted in DYT1

  7. The Cruciate Ligaments in Total Knee Arthroplasty.

    Science.gov (United States)

    Parcells, Bertrand W; Tria, Alfred J

    2016-01-01

    The early knee replacements were hinge designs that ignored the ligaments of the knee and resurfaced the joint, allowing freedom of motion in a single plane. Advances in implant fixation paved the way for modern designs, including the posterior-stabilized (PS) total knee arthroplasty (TKA) that sacrifices both cruciate ligaments while substituting for the posterior cruciate ligament (PCL), and the cruciate-retaining (CR) TKA designs that sacrifice the anterior cruciate ligament but retain the PCL. The early bicruciate retaining (BCR) TKA designs suffered from loosening and early failures. Townley and Cartier designed BCR knees that had better clinical results but the surgical techniques were challenging.Kinematic studies suggest that normal motion relies on preservation of both cruciate ligaments. Unicompartmental knee arthroplasty retains all knee ligaments and closely matches normal motion, while PS and CR TKA deviate further from normal. The 15% to 20% dissatisfaction rate with current TKA has renewed interest in the BCR design. Replication of normal knee kinematics and proprioception may address some of the dissatisfaction. PMID:27327919

  8. The INDUS knee prosthesis - Prospective multicentric trial of a posteriorly stabilized high-flex design: 2 years follow-up

    Directory of Open Access Journals (Sweden)

    Sancheti Kantilal

    2009-01-01

    Full Text Available Background: The anatomical and morphological differences and high-flexion daily activities in the Asian population have since ever prompted for development of customized knee replacement systems. INDUS knee system has advantages both of high-flex designs and is developed by keeping the anatomical variations of the native population in mind. The purpose of this study is to analyze the 2-year follow-up results using the INDUS prosthesis. Materials and Methods: Two hundred and ninety-seven knees in 276 patients were prospectively analyzed. There were 65 men (72 knees and 211 (225 knees women with a mean age of 64.56 years. Two hundred and forty-five knees had primary osteoarthritis, 48 knees had rheumatoid arthritis, and four knees had post-traumatic arthritis. Clinical parameters, including the Knee Society scores (knee score and function score, range of motion, post-operative anterior knee pain, and complications were recorded. Pre- and post-operative serial radiographs were analyzed for limb alignment, component positioning, and evidence of loosening. Results: The patients were followed-up for an average of 2.59 years (range, 2-3.3 years. The mean knee score and the mean function score were significantly improved from a pre-operative value of 39.4 points and 46.7 points to a post-operative value of 87 points and 86 points, respectively (P value < 0.05. Two hundred and thirty four knees had no anterior knee pain while 63 knees had mild to moderate pain, but none of the patients requested any intervention for the same. Of the 276 patients (297 knees, 79 knees had flexion above 140°, 167 had a flexion range of 130-140°, 27 had a flexion range of 100-130°, and 24 knees had a flexion < 100°, with the mean range of movement being 132.9°. Improvements in the range of movement were retained over time and a total of 205 patients (224 knees, 75.7% could squat or sit cross-legged at the final follow-up. The mean tibiofemoral angle was 8.5°± 6.9º of

  9. Effect of continuous passive motion on functional recovery after senile arthroscope operation of knee joint%持续被动活动对老年膝关节镜术后功能恢复的作用

    Institute of Scientific and Technical Information of China (English)

    李泓

    2003-01-01

    @@ INTRODUCTION With popularit and development of arthroscope technique, it has been broadly ursed in treatment of disease of knee joint. Rehabilitation after arthroscope operation especially after senile arthxoscope operation of knee joint is very important.

  10. Design of a Knee Exoskeleton Using Foot Pressure and Knee Torque Sensors

    Directory of Open Access Journals (Sweden)

    Jung-Hoon Kim

    2015-08-01

    Full Text Available This study presents the development of a modular knee exoskeleton system that supports the knee joints of hemiplegic patients. The device is designed to realize the polycentric motion of real human knees using a fourbar linkage and to minimize its total weight. In order to determine the user’s intention, force-sensitive resistors (FSRs in the user’s insole, a torque sensor on the robot knee joint, and an encoder in the motor are used. The control algorithm is based on a finite state machine (FSM, where the force control, position control and virtual damping control are applied in each state. The proposed hardware design and algorithm are verified by performing experiments on the standing, walking and sitting motion controls while wearing the knee exoskeleton.

  11. The Waist Width of Skis Influences the Kinematics of the Knee Joint in Alpine Skiing

    Directory of Open Access Journals (Sweden)

    Martin Zorko, Bojan Nemec, Jan Babič, Blaz Lešnik, Matej Supej

    2015-09-01

    Full Text Available Recently alpine skis with a wider waist width, which medially shifts the contact between the ski edge and the snow while turning, have appeared on the market. The aim of this study was to determine the knee joint kinematics during turning while using skis of different waist widths (65mm, 88mm, 110mm. Six highly skilled skiers performed ten turns on a predefined course (similar to a giant slalom course. The relation of femur and tibia in the sagital, frontal and coronal planes was captured by using an inertial motion capture suit, and Global Navigation Satellite System was used to determine the skiers’ trajectories. With respect of the outer ski the knee joint flexion, internal rotation and abduction significantly decreased with the increase of the ski waist width for the greatest part of the ski turn. The greatest abduction with the narrow ski and the greatest external rotation (lowest internal rotation with the wide ski are probably the reflection of two different strategies of coping the biomechanical requirements in the ski turn. These changes in knee kinematics were most probably due to an active adaptation of the skier to the changed biomechanical conditions using wider skis. The results indicated that using skis with large waist widths on hard, frozen surfaces could bring the knee joint unfavorably closer to the end of the range of motion in transversal and frontal planes as well as potentially increasing the risk of degenerative knee injuries.

  12. Robust multi-dimensional motion features for first-person vision activity recognition

    OpenAIRE

    Abebe, Girmaw; Cavallaro, Andrea; Llanas Parra, Francesc Xavier

    2016-01-01

    We propose robust multi-dimensional motion features for human activity recognition from first-person videos. The proposed features encode information about motion magnitude, direction and variation, and combine them with virtual inertial data generated from the video itself. The use of grid flow representation, per-frame normalization and temporal feature accumulation enhances the robustness of our new representation. Results on multiple datasets demonstrate that the proposed feature represen...

  13. Total knee arthroplasty for severe valgus knee deformity

    Institute of Scientific and Technical Information of China (English)

    Zhou Xinhua; Wang Min; Liu Chao; Zhang Liang; Zhou Yixin

    2014-01-01

    Background Primary total knee arthroplasty (TKA) in severe valgus knees may prove challenging,and choice of implant depends on the severity of the valgus deformity and the extent of soft-tissue release.The purpose of this study was to review 8 to 11 years (mean,10 years) follow-up results of primary TKA for varient-Ⅲ valgus knee deformity with use of different type implants.Methods Between January 2002 and January 2005,20 women and 12 men,aged 47 to 63 (mean,57.19±6.08) years old,with varient-Ⅲ valgus knees underwent primary TKA.Of the 32 patients,37 knees had varient-Ⅲ deformities.Pie crusting was carefully performed with small,multiple inside-out incisions,bone resection balanced the knee in lieu of soft tissue releases that were not used in the series.Cruciate-retaining knees (Gemini MKⅡ,Link Company,Germany) were used in 13 knees,Genesis Ⅱ (Simth & Nephew Company,USA) in 14 knees,and hinged knee (Endo-Model Company,Germany) in 10 knees.In five patients with bilateral variant-Ⅲll TKAs,three patients underwent 1-stage bilateral procedures,and two underwent 2-stage procedures.All implants were cemented and the patella was not resurfaced.The Hospital for Special Surgery (HSS) knee score was assessed.Patients were followed up from 8 to 11 years.Results The mean HSS knee score were improved from 50.33±11.60 to 90.06±3.07 (P <0.001).The mean tibiofemoral alignment were improved from valgus 32.72°±9.68° pre-operation to 4.89°±0.90° post-operation (P <0.001).The mean range of motion were improved from 93.72°±23.69° pre-operation to 116.61±16.29° post-operation (P <0.001).No patients underwent revision.One patient underwent open reduction and internal fixation using femoral condylar plates for supracondylar femoral fractures secondary to a fall at three years.Three patients developed transient peroneal nerve palsies,which resolved within nine months.Two patients developed symptomatic deep vein thrombosis that was managed with rivaroxaban

  14. What Are the Prognostic Factors for Radiographic Progression of Knee Osteoarthritis? A Meta-analysis

    NARCIS (Netherlands)

    A.N. Bastick (Alex); J.N. Belo (Janneke); J. Runhaar (Jos); S.M. Bierma-Zeinstra (Sita)

    2015-01-01

    textabstractBackground: A previous systematic review on prognostic factors for knee osteoarthritis (OA) progression showed associations for generalized OA and hyaluronic acid levels. Knee pain, radiographic severity, sex, quadriceps strength, knee injury, and regular sport activities were not associ

  15. Effects of attention and perceptual uncertainty on cerebellar activity during visual motion perception.

    Science.gov (United States)

    Baumann, Oliver; Mattingley, Jason B

    2014-02-01

    Recent clinical and neuroimaging studies have revealed that the human cerebellum plays a role in visual motion perception, but the nature of its contribution to this function is not understood. Some reports suggest that the cerebellum might facilitate motion perception by aiding attentive tracking of visual objects. Others have identified a particular role for the cerebellum in discriminating motion signals in perceptually uncertain conditions. Here, we used functional magnetic resonance imaging to determine the degree to which cerebellar involvement in visual motion perception can be explained by a role in sustained attentive tracking of moving stimuli in contrast to a role in visual motion discrimination. While holding the visual displays constant, we manipulated attention by having participants attend covertly to a field of random-dot motion or a colored spot at fixation. Perceptual uncertainty was manipulated by varying the percentage of signal dots contained within the random-dot arrays. We found that attention to motion under high perceptual uncertainty was associated with strong activity in left cerebellar lobules VI and VII. By contrast, attending to motion under low perceptual uncertainty did not cause differential activation in the cerebellum. We found no evidence to support the suggestion that the cerebellum is involved in simple attentive tracking of salient moving objects. Instead, our results indicate that specific subregions of the cerebellum are involved in facilitating the detection and discrimination of task-relevant moving objects under conditions of high perceptual uncertainty. We conclude that the cerebellum aids motion perception under conditions of high perceptual demand. PMID:23982589

  16. Kettlebell swing, snatch, and bottoms-up carry: back and hip muscle activation, motion, and low back loads.

    Science.gov (United States)

    McGill, Stuart M; Marshall, Leigh W

    2012-01-01

    The intent of this study was to quantify spine loading during different kettlebell swings and carries. No previously published studies of tissue loads during kettlebell exercises could be found. Given the popularity of kettlebells, this study was designed to provide an insight into the resulting joint loads. Seven male subjects participated in this investigation. In addition, a single case study of the kettlebell swing was performed on an accomplished kettlebell master. Electromyography, ground reaction forces (GRFs), and 3D kinematic data were recorded during exercises using a 16-kg kettlebell. These variables were input into an anatomically detailed biomechanical model that used normalized muscle activation; GRF; and spine, hip, and knee motion to calculate spine compression and shear loads. It was found that kettlebell swings create a hip-hinge squat pattern characterized by rapid muscle activation-relaxation cycles of substantial magnitudes (∼50% of a maximal voluntary contraction [MVC] for the low back extensors and 80% MVC for the gluteal muscles with a 16-kg kettlebell) resulting in about 3,200 N of low back compression. Abdominal muscular pulses together with the muscle bracing associated with carries create kettlebell-specific training opportunities. Some unique loading patterns discovered during the kettlebell swing included the posterior shear of the L4 vertebra on L5, which is opposite in polarity to a traditional lift. Thus, quantitative analysis provides an insight into why many individuals credit kettlebell swings with restoring and enhancing back health and function, although a few find that they irritate tissues. PMID:21997449

  17. Translational Optic Flow Induces Shifts in Direction of Active Forward and Backward Self-Motion

    Directory of Open Access Journals (Sweden)

    Kenzo Sakurai

    2011-05-01

    Full Text Available Previously, we reported that when observers passively experience real linear oscillatory somatic motion while viewing orthogonal visual optic flow patterns, their perceived motion direction is intermediate to those specified by visual and vestibular information individually (Sakurai et al., 2002, ACV; 2003, ECVP; 2010, VSS; Kubodera et al., 2010, APCV. Here, we extend those studies to active somatic motion, measuring the angular shift in body direction after active body motion while viewing synchronized orthogonal optic flow. Experimental visual stimuli consisted of 1 second of translating leftward (rightward random-dots and 1 second of random noise. Control stimuli consisted of two 1-second intervals of random noise separated by a static interval. Observers viewed the stimulus for 30 seconds through a face-mounted display while actively stepping forward and backward such that their forward body movement was synchronized with the random-dot translational motion. Observers' body direction was measured before and after each trial. Translational optic flow induced shifts in body direction that were opposite to shifts in perceived direction with passive viewing in our previous reports. Observers may have compensated their body motion in response to perceived direction shifts similar to those we reported for passive viewing.

  18. Classification Accuracies of Physical Activities Using Smartphone Motion Sensors

    OpenAIRE

    Wu, Wanmin; Dasgupta, Sanjoy; Ramirez, Ernesto E; Peterson, Carlyn; Norman, Gregory J.

    2012-01-01

    Background Over the past few years, the world has witnessed an unprecedented growth in smartphone use. With sensors such as accelerometers and gyroscopes on board, smartphones have the potential to enhance our understanding of health behavior, in particular physical activity or the lack thereof. However, reliable and valid activity measurement using only a smartphone in situ has not been realized. Objective To examine the validity of the iPod Touch (Apple, Inc.) and particularly to understand...

  19. 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.

  20. Addition of telephone coaching to a physiotherapist-delivered physical activity program in people with knee osteoarthritis: A randomised controlled trial protocol

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2012-12-01

    Full Text Available Abstract Background Knee osteoarthritis (OA is one of the most common and costly chronic musculoskeletal conditions world-wide and is associated with substantial pain and disability. Many people with knee OA also experience co-morbidities that further add to the OA burden. Uptake of and adherence to physical activity recommendations is suboptimal in this patient population, leading to poorer OA outcomes and greater impact of associated co-morbidities. This pragmatic randomised controlled trial will investigate the clinical- and cost-effectiveness of adding telephone coaching to a physiotherapist-delivered physical activity intervention for people with knee OA. Methods/Design 168 people with clinically diagnosed knee OA will be recruited from the community in metropolitan and regional areas and randomly allocated to physiotherapy only, or physiotherapy plus nurse-delivered telephone coaching. Physiotherapy involves five treatment sessions over 6 months, incorporating a home exercise program of 4–6 exercises (targeting knee extensor and hip abductor strength and advice to increase daily physical activity. Telephone coaching comprises 6–12 telephone calls over 6 months by health practitioners trained in applying the Health Change Australia (HCA Model of Health Change to provide behaviour change support. The telephone coaching intervention aims to maximise adherence to the physiotherapy program, as well as facilitate increased levels of participation in general physical activity. The primary outcomes are pain measured by an 11-point numeric rating scale and self-reported physical function measured by the Western Ontario and McMaster Universities Osteoarthritis Index subscale after 6 months. Secondary outcomes include physical activity levels, quality-of-life, and potential moderators and mediators of outcomes including self-efficacy, pain coping and depression. Relative cost-effectiveness will be determined from health service usage and outcome

  1. Treatment of knee flexion contracture in patients with chronic juvenile arthritis: A case report

    Directory of Open Access Journals (Sweden)

    Matijević Radmila

    2006-01-01

    Full Text Available Introduction. Knee flexion contractures are common after-effects of juvenile arthritis. Treatment is usually conservative and may include physical therapy and kinesitherapy. Surgical treatment, particularly of the soft parts, indicated for contractures resistant to conservative treatment, helps to correct the deformity, maintain movements, and relieves pain. Intensive postoperative physiotherapy is of special importance. Case report. A 23-year-old female patient with chronic juvenile arthritis since the age of one was admitted for treatment of flexion con­tractures in both knees, muscle hypotrophy, loss of strength and gait disability. The patient underwent arthroscopic synovectomy. The operation was first performed on the right and after 3 mouths on the left knee. The pre operative range of motion in the rigth knee was 30°-70° and in the left 40°-80°. The patient underwent intensive physical therapy to reduce postoperative swelling of knees and firstly passive and then active kinesitherapy. Nine months after the first surgery and six months after the second, the range of motion in the right knee was 0°-100° and in the left 0°-105°. The strength of tested muscles was increased and gait was improved. Conclusion. Management and rehabilitation of patients with chronic juvenile arthritis include maintenance or improvement in position and function of joints that is achieved with synovectomy. The results depend on combined interdisciplinary rehabilitation, well-experienced staff, and pre- and post-operative physiotherapy as well as kinesitherapy. Arthroscopic synovectomy has many advantages and we believe that it was a better solution than open capsulosynovectomy in this patient with chronic juvenile arthritis of the knee. .

  2. PENINGKATAN PRODUKTIVITAS DAN EFISIENSI BIAYA MELALUI INTEGRASI TIME & MOTION STUDY DAN ACTIVITY-BASED COSTING

    Directory of Open Access Journals (Sweden)

    Monika Kussetya Ciptani

    2001-01-01

    Full Text Available Organizations today have many activities that increase continuously. There are some activities that companies have to do to meet customers' need. Some companies try to increase efficiency in performing their activities and try to measure activities they do although the difficulties in measuring each activities are very high. In this case, time & motion study method is one of the solutions to help the company measuring their activity. The company's activity consume time and resources, that is why time & motion study provides many techniques to measure activity in the company, for example: work sampling method, work-unit activity, time standard method, etc. Using these techniques, company can measure the productivity of resources used for every activity. In order to get better performance in cost reduction, the company should assign their cost to the product resulted. The method used is Activity-Based Costing method (ABC method. ABC method gives better result in assigning indirect costs to the product because it assigns costs to the product according to their activity. ABC method is the most appropriate method to be integrated with time & motion study method. The integration of the two methods could increase the ability of a company to measure and to control their productivity and cost efficiency in order to satisfy customers' demand. Abstract in Bahasa Indonesia : Kemajuan perusahaan sebagai organisasi bisnis, membuat aktivitas yang dilakukan oleh perusahaan semakin meningkat. Berbagai macam aktivitas dilakukan oleh perusahaan dalam rangka memenuhi apa yang menjadi kebutuhan dan keinginan customer. Perusahaan berusaha untuk meningkatkan efisiensi aktivitas dan melakukan pengukuran tingkat aktivitas yang dilakukan, padahal tingkat kesulitan yang dihadapi perusahaan untuk melakukan pengukuran setiap aktivitas yang dilakukan cukup tinggi. Metode time & motion study memberikan solusi bagi perusahaan untuk melakukan pengukuran tingkat aktivitas yang

  3. Embodied Semiotic Activities and Their Role in the Construction of Mathematical Meaning of Motion Graphs

    Science.gov (United States)

    Botzer, Galit; Yerushalmy, Michal

    2008-01-01

    This paper examines the relation between bodily actions, artifact-mediated activities, and semiotic processes that students experience while producing and interpreting graphs of two-dimensional motion in the plane. We designed a technology-based setting that enabled students to engage in embodied semiotic activities and experience two modes of…

  4. The Effect of Continuous Passive Motion after Total Knee Replacement%人工全膝关节置换术后持续被动运动的早期临床效果研究

    Institute of Scientific and Technical Information of China (English)

    范继峰; 张卫国; 李杰; 宫福良

    2011-01-01

    探讨持续被动运动用于人工全膝关节置换术后的早期疗效.自2008年至2010年我科共完成人工全膝关节置换术36例(43膝),将全部病例随机分为2组,A组术后单纯应用物理治疗及自身锻炼,B组采用持续被动锻炼加主动锻炼.观察术后12小时、24小时引流量,术后1周、2周膝关节主动活动范围,切口拆线时间,患者平均住院时间.术后2周彩超检查下肢深静脉血栓的发生情况.2组间在术后12小时、24小时引流量,切口拆线时间,患者平均住院时间及术后2周下肢深静脉血栓的发生率方面均无显著差异(P>0.05).术后第1周及第2周关节主动活动范围方面B组明显优于A组(P<0.05).使用持续被动运动可明显增加人工全膝关节置换术后早期膝关节主动运动范围,并不增加切口并发症的发生率.%To evaluate the early clinical effects of continuous passive motion (CPM ) after total knee replacement (TKR). From 2008 to 2010,36 patients (43 knees) who underwent TKR were divided into 2 groups. Group B were treated with CPM after operation,compared to group A with single physiotherapy and initiative exercise. There was statistically significant difference between the two groups in range of motion (ROM ) in 1 and 2 week after operation. CPM is benefit to the ROM of the joint in early stage post operation.

  5. Treatment of knee arthrofibrosis and quadriceps insufficiency after patellar tendon repair: a case report including use of the graston technique.

    Science.gov (United States)

    Black, Douglass W

    2010-06-23

    Arthrofibrosis of the knee is a surgical complication that can limit range of motion, inhibit muscle activity, and decrease patient function. Optimal conservative treatment has not been well established in the literature, leaving a clinician with limited evidence for treatment planning. Described here is part of the rehabilitative course of care for a patient with arthrofibrotic limitations after a mid-substance patellar tendon repair with augmentation. Marked limitations in knee flexion range of motion and quadriceps activity were addressed using the Graston Technique to deal with soft-tissue adhesions; traditional physical therapy care was also provided. Clear improvement in range of motion and quadriceps activity and function was noted over the course of 5 treatments during 1 month. Treatment process and clinical reasoning are offered to promote understanding and to facilitate future inquiry.

  6. POST TRAUMATIC KNEE FRACTURE ( X-RAY

    Directory of Open Access Journals (Sweden)

    Dr. Jalaja Prakash.

    2013-06-01

    Full Text Available A 51 year old male patient met with a road traffic accident on August 2010. On examination thepatient was unable to stand and walk. His right knee was swollen and complained of pain withinstability. The X-Ray of patient showed transverse fracture of patella along with comminutedfracture of lower end of femur. He was treated with “K” wire and internal fixation. The patient wasadvised early physiotherapy which include range of motion exercises, knee strengthening and gaittraining.

  7. Fusion of Smartphone Motion Sensors for Physical Activity Recognition

    NARCIS (Netherlands)

    Shoaib, Muhammad; Bosch, Stephan; Durmaz Incel, Ozlem; Scholten, Hans; Havinga, Paul J.M.

    2014-01-01

    For physical activity recognition, smartphone sensors, such as an accelerometer and a gyroscope, are being utilized in many research studies. So far, particularly, the accelerometer has been extensively studied. In a few recent studies, a combination of a gyroscope, a magnetometer (in a supporting r

  8. Spontaneous Motion in Hierarchically Assembled Active Cellular Materials

    Science.gov (United States)

    Chen, Daniel

    2013-03-01

    With exquisite precision and reproducibility, cells orchestrate the cooperative action of thousands of nanometer-sized molecular motors to carry out mechanical tasks at much larger length scales, such as cell motility, division and replication. Besides their biological importance, such inherently far-from-equilibrium processes are an inspiration for the development of soft materials with highly sought after biomimetic properties such as autonomous motility and self-healing. I will describe our exploration of such a class of biologically inspired soft active materials. Starting from extensile bundles comprised of microtubules and kinesin, we hierarchically assemble active analogs of polymeric gels, liquid crystals and emulsions. At high enough concentration, microtubule bundles form an active gel network capable of generating internally driven chaotic flows that enhance transport and fluid mixing. When confined to emulsion droplets, these 3D networks buckle onto the water-oil interface forming a dense thin film of bundles exhibiting cascades of collective buckling, fracture, and self-healing driven by internally generated stresses from the kinesin clusters. When compressed against surfaces, this active nematic cortex exerts traction stresses that propel the locomotion of the droplet. Taken together, these observations exemplify how assemblies of animate microscopic objects exhibit collective biomimetic properties that are fundamentally distinct from those found in materials assembled from inanimate building blocks. These assemblies, in turn, enable the generation of a new class of materials that exhibit macroscale flow phenomena emerging from nanoscale components.

  9. Gait Using Pneumatic Brace for End-Stage Knee Osteoarthritis.

    Science.gov (United States)

    Kapadia, Bhaveen H; Cherian, Jeffrey Jai; Starr, Roland; Chughtai, Morad; Mont, Michael A; Harwin, Steven F; Bhave, Anil

    2016-04-01

    More than 20 million individuals in the United States are affected by knee osteoarthritis (OA), which can lead to altered biomechanics and excessive joint loading. The use of an unloader pneumatic brace with extension assist has been proposed as a nonoperative treatment modality that may improve gait mechanics and correct knee malalignment. We assessed the following parameters in patients who have knee OA treated with and without a brace: (1) changes in temporospatial parameters in gait; (2) knee range of motion, knee extension at heel strike, and foot placement; (3) knee joint moments and impulse; and (4) changes in dynamic stiffness and rate of change of knee flexion during midstance to terminal stance. This 2:1 prospective, randomized, single-blinded trial evaluated 36 patients (24 brace and 12 matching). OA knee patients were randomized to receive either a pneumatic unloader brace or a standard nonoperative treatment regimen as the matching cohort for a 3-month period. They underwent evaluation of gait parameters using a three-dimensional gait analysis system at their initial appointment and at 3 months follow-up. All the testing, pre- and postbracing were performed without wearing the brace to examine for retained effects. Treatment with the brace led to significant improvements versus standard treatment in various gait parameters. Patients in the brace group had improvements in walking speed, knee extension at heel strike, total range of motion, knee joint forces, and rate of knee flexion from midstance to terminal stance when compared with the matching cohort. Knee OA patients who used a pneumatic unloader brace for 3 months for at least 3 hours per day had significant improvements various gait parameters when compared with a standard nonoperative therapy cohort. Braced patients demonstrated gait-modifying affects when not wearing the brace. These results are encouraging and suggest that this device represents a promising treatment modality for knee OA that

  10. Knee pain (image)

    Science.gov (United States)

    ... front of the knee can be due to bursitis, arthritis, or softening of the patella cartilage as ... knee. Overall knee pain can be due to bursitis, arthritis, tears in the ligaments, osteoarthritis of the ...

  11. Knee arthroscopy - discharge

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000199.htm Knee arthroscopy - discharge To use the sharing features on ... had surgery to check for problems in your knee (knee arthroscopy). You may have been checked for: ...

  12. Knee microfracture surgery

    Science.gov (United States)

    Cartilage regeneration - knee ... Three types of anesthesia may be used for knee arthroscopy surgery: Medicine to relax you, and shots of painkillers to numb the knee Spinal (regional) anesthesia General anesthesia (you will be ...

  13. DEFINITION AND ANALYSIS OF MOTION ACTIVITY AFTER-STROKE PATIENT FROM THE VIDEO STREAM

    Directory of Open Access Journals (Sweden)

    M. Yu. Katayev

    2014-01-01

    Full Text Available This article describes an approach to the assessment of motion activity of man in after-stroke period, allowing the doctor to get new information to give a more informed recommendations on rehabilitation treatment than in traditional approaches. Consider description of the hardware-software complex for determination and analysis of motion activity after-stroke patient for the video stream. The article provides a description of the complex, its algorithmic filling and the results of the work on the example of processing of the actual data. The algorithms and technology to significantly accelerate the gait analysis and improve the quality of diagnostics post-stroke patients.

  14. A conceptual framework for a sports knee injury performance profile (SKIPP) and return to activity criteria (RTAC)

    OpenAIRE

    David Logerstedt; Amelia Arundale; Andrew Lynch; Lynn Snyder-Mackler

    2015-01-01

    ABSTRACTInjuries to the knee, including intra-articular fractures, ligamentous ruptures, and meniscal and articular cartilage lesions, are commonplace within sports. Despite advancements in surgical techniques and enhanced rehabilitation, athletes returning to cutting, pivoting, and jumping sports after a knee injury are at greater risk of sustaining a second injury. The clinical utility of objective criteria presents a decision-making challenge to ensure athletes are fully rehabilitated and ...

  15. Clinical Evaluation of a Mobile Sensor-Based Gait Analysis Method for Outcome Measurement after Knee Arthroplasty

    Directory of Open Access Journals (Sweden)

    Tilman Calliess

    2014-08-01

    Full Text Available Clinical scores and motion-capturing gait analysis are today’s gold standard for outcome measurement after knee arthroplasty, although they are criticized for bias and their ability to reflect patients’ actual quality of life has been questioned. In this context, mobile gait analysis systems have been introduced to overcome some of these limitations. This study used a previously developed mobile gait analysis system comprising three inertial sensor units to evaluate daily activities and sports. The sensors were taped to the lumbosacral junction and the thigh and shank of the affected limb. The annotated raw data was evaluated using our validated proprietary software. Six patients undergoing knee arthroplasty were examined the day before and 12 months after surgery. All patients reported a satisfactory outcome, although four patients still had limitations in their desired activities. In this context, feasible running speed demonstrated a good correlation with reported impairments in sports-related activities. Notably, knee flexion angle while descending stairs and the ability to stop abruptly when running exhibited good correlation with the clinical stability and proprioception of the knee. Moreover, fatigue effects were displayed in some patients. The introduced system appears to be suitable for outcome measurement after knee arthroplasty and has the potential to overcome some of the limitations of stationary gait labs while gathering additional meaningful parameters regarding the force limits of the knee.

  16. Clinical evaluation of a mobile sensor-based gait analysis method for outcome measurement after knee arthroplasty.

    Science.gov (United States)

    Calliess, Tilman; Bocklage, Raphael; Karkosch, Roman; Marschollek, Michael; Windhagen, Henning; Schulze, Mareike

    2014-08-28

    Clinical scores and motion-capturing gait analysis are today's gold standard for outcome measurement after knee arthroplasty, although they are criticized for bias and their ability to reflect patients' actual quality of life has been questioned. In this context, mobile gait analysis systems have been introduced to overcome some of these limitations. This study used a previously developed mobile gait analysis system comprising three inertial sensor units to evaluate daily activities and sports. The sensors were taped to the lumbosacral junction and the thigh and shank of the affected limb. The annotated raw data was evaluated using our validated proprietary software. Six patients undergoing knee arthroplasty were examined the day before and 12 months after surgery. All patients reported a satisfactory outcome, although four patients still had limitations in their desired activities. In this context, feasible running speed demonstrated a good correlation with reported impairments in sports-related activities. Notably, knee flexion angle while descending stairs and the ability to stop abruptly when running exhibited good correlation with the clinical stability and proprioception of the knee. Moreover, fatigue effects were displayed in some patients. The introduced system appears to be suitable for outcome measurement after knee arthroplasty and has the potential to overcome some of the limitations of stationary gait labs while gathering additional meaningful parameters regarding the force limits of the knee.

  17. The Waist Width of Skis Influences the Kinematics of the Knee Joint in Alpine Skiing.

    Science.gov (United States)

    Zorko, Martin; Nemec, Bojan; Babič, Jan; Lešnik, Blaz; Supej, Matej

    2015-09-01

    Recently alpine skis with a wider waist width, which medially shifts the contact between the ski edge and the snow while turning, have appeared on the market. The aim of this study was to determine the knee joint kinematics during turning while using skis of different waist widths (65mm, 88mm, 110mm). Six highly skilled skiers performed ten turns on a predefined course (similar to a giant slalom course). The relation of femur and tibia in the sagital, frontal and coronal planes was captured by using an inertial motion capture suit, and Global Navigation Satellite System was used to determine the skiers' trajectories. With respect of the outer ski the knee joint flexion, internal rotation and abduction significantly decreased with the increase of the ski waist width for the greatest part of the ski turn. The greatest abduction with the narrow ski and the greatest external rotation (lowest internal rotation) with the wide ski are probably the reflection of two different strategies of coping the biomechanical requirements in the ski turn. These changes in knee kinematics were most probably due to an active adaptation of the skier to the changed biomechanical conditions using wider skis. The results indicated that using skis with large waist widths on hard, frozen surfaces could bring the knee joint unfavorably closer to the end of the range of motion in transversal and frontal planes as well as potentially increasing the risk of degenerative knee injuries. Key pointsThe change in the skis' waist width caused a change in the knee joint movement strategies, which had a tendency to adapt the skier to different biomechanical conditions.The use of wider skis or, in particular, skis with a large waist width, on a hard or frozen surface, could unfavourably bring the knee joint closer to the end of range of motion in transversal and frontal planes as well as may potentially increase the risk of degenerative knee injuries.The overall results of the abduction and internal

  18. MAGNETIC HELICITY TRANSPORTED BY FLUX EMERGENCE AND SHUFFLING MOTIONS IN SOLAR ACTIVE REGION NOAA 10930

    International Nuclear Information System (INIS)

    We present a new methodology which can determine magnetic helicity transport by the passage of helical magnetic field lines from the sub-photosphere and the shuffling motions of footpoints of preexisting coronal field lines separately. It is well known that only the velocity component, which is perpendicular to the magnetic field (υB), has contributed to the helicity accumulation. Here, we demonstrate that υB can be deduced from a horizontal motion and vector magnetograms under a simple relation of υt = μt + (υn/Bn ) Bt, as suggested by Démoulin and Berger. Then after dividing υB into two components, as one is tangential and the other is normal to the solar surface, we can determine both terms of helicity transport. Active region (AR) NOAA 10930 is analyzed as an example during its solar disk center passage by using data obtained by the Spectropolarimeter and the Narrowband Filter Imager of Solar Optical Telescope on board Hinode. We find that in our calculation the helicity injection by flux emergence and shuffling motions have the same sign. During the period we studied, the main contribution of helicity accumulation comes from the flux emergence effect, while the dynamic transient evolution comes from the shuffling motions effect. Our observational results further indicate that for this AR the apparent rotational motion in the following sunspot is the real shuffling motions on the solar surface.

  19. Confiabilidade intra-avaliador da medida de amplitude de movimento da flexão e extensão do joelho pelo método de fotogrametria Intra-rater reliability of knee flexion and extension range of motion measurement through the photogrammetry method

    Directory of Open Access Journals (Sweden)

    Eurico Peixoto César

    2012-03-01

    Full Text Available Apesar de existirem diversos métodos para a determinação da amplitude de movimento (ADM, a baixa confiabilidade, a pouca sensibilidade, a subjetividade ou a ausência de valores do erro típico da medida (ETM de alguns desses métodos comprometem a interpretação adequada dos resultados. O objetivo deste estudo foi determinar a confiabilidade intra-avaliador da medida e do método de fotogrametria para a ADM de extensão ativa e flexão passiva do joelho (FPJ, realizada no mesmo dia (consistência interna e em dias diferentes (estabilidade. Participaram 18 sujeitos do sexo masculino (24,5±3,7 anos, 79,3±10,1 kg e 174,8±4,2 cm. Após a marcação dos pontos anatômicos de referência, a angulação dos movimentos foi registrada em fotografia, por meio da ferramenta de dimensão angular no software CorelDRAW®. A confiabilidade da medida e do instrumento foi estabelecida pelo coeficiente de correlação intraclasse (CCI e pelo cálculo do ETM. A distribuição dos erros dos dados foi verificada pela representação gráfica de Bland e Altman. O método apresentou confiabilidade perfeita (ETM=0,01 e CCI=1,0 para ambos os movimentos. Para a confiabilidade da medida, foram encontrados os valores 0,97 e 0,93 para consistência interna e 0,96 e 0,83 para estabilidade (ETM=2,9 e 4,0%; pAlthough there are several methods for determining the range of motion (ROM, low reliability, low sensitivity, subjectivity or lack of information related to the typical error of measurement (TEM may compromise interpretation of testing results. The aim of this study was to test the intra-rater reliability of the ROM measurement and the photogrammetry method for same day (internal consistency and between days (stability for knee active extension and passive flexion. Eighteen active male volunteers (24.5±3.7 years, 79.3±10.1 kg and 174.8±4.2 cm were selected to participate in the study. After identification of anatomical landmarks used for reference, knee passive

  20. Circadian Rest/Activity Rhythms in Knee Osteoarthritis with Insomnia: A Study of Osteoarthritis Patients and Pain-Free Controls with Insomnia or Normal Sleep

    OpenAIRE

    Spira, Adam P.; Runko, Virginia T.; Finan, Patrick H.; Kaufmann, Christopher N.; Bounds, Sara C; Liu, Lianqi; Buenaver, Luis F.; McCauley, Lea M.; Ancoli-Israel, Sonia; Smith, Michael T

    2014-01-01

    Aberrant circadian rest/activity rhythms (RARs) may promote poor aging-related health outcomes. Osteoarthritis and chronic insomnia are common age-related conditions, but the circadian RARs of each group have not been well characterized or compared. We evaluated actigraphic RARs in individuals with: (1) knee osteoarthritis (KOA) only; (2) chronic insomnia only; (3) KOA + insomnia; and (4) pain-free good sleepers. Compared to participants with KOA only, those with KOA + insomnia had less robus...

  1. [Knee endoprosthesis: sports orthopedics possibilities and limitations].

    Science.gov (United States)

    Kuster, M S; Grob, K; Gächter, A

    2000-08-01

    Many patients would like to resume some sport activities after total knee replacement; however, most recommendations are based on subjective opinion rather than scientific evidence. The following paper presents a literature review of sports after total knee replacement and includes recommendations which are based on biomechanical laws. Most total knee designs show increased conformity near full extension. Beyond a certain knee flexion angle, the conformity ratio decreases due to a reduced femoral radius. Therefore, these designs accept higher loads near full extension than in flexion. In order to recommend suitable physical activities after total knee replacement, both the load and the knee flexion angle of the peak load must be considered. It has been shown that power walking and cycling produce the lowest polyethylene inlay stress of a total knee replacement and seem to be the least demanding endurance activities. Jogging and downhill walking show high inlay stress levels and should be avoided. Hence, for mountain hiking, patients are advised to avoid descents or at least use skipoles and walk slowly downhill to reduce the load on the knee joint. It must also be mentioned that any activity represents additional wear, which may affect the long-term results of total knee replacements. Further clinical studies are necessary to validate the biomechanical investigations. PMID:11013918

  2. Severe Heterotopic Ossification following Total Knee Replacement

    Directory of Open Access Journals (Sweden)

    Alexander L. Dodds

    2014-01-01

    Full Text Available Although the incidence of minor heterotopic ossification is probably higher than what is usually expected, severe heterotopic ossification (HO is an extremely rare event following total knee replacement surgery. We present the case of a 66-year-old woman who initially had achieved an excellent range of motion following bilateral uncemented rotating platform total knee replacement, before presenting with pain and loss of range of motion at 2 months after surgery. Severe HO was diagnosed on X-rays. Treatment consisted of nonoperative measures only, including physiotherapy with hydrotherapy and anti-inflammatories. She eventually regained her range of motion when seen at 8 months after operation. This case illustrates that nonoperative treatment without the use of radiotherapy or surgery can be used to safely resolve stiffness caused by HO after total knee replacement.

  3. Can origin of the 2400-year cycle of solar activity be caused by solar inertial motion?

    Directory of Open Access Journals (Sweden)

    I. Charvátová

    Full Text Available A solar activity cycle of about 2400 years has until now been of uncertain origin. Recent results indicate it is caused by solar inertial motion. First we describe the 178.7-year basic cycle of solar motion. The longer cycle, over an 8000 year interval, is found to average 2402.2 years. This corresponds to the Jupiter/Heliocentre/Barycentre alignments (9.8855 × 243. Within each cycle an exceptional segment of 370 years has been found characterized by a looping pattern by a trefoil or quasitrefoil geometry. Solar activity, evidenced by 14C tree-ring proxies, shows the same pattern. Solar motion is computable in advance, so this provides a basis for future predictive assessments. The next 370-year segment will occur between AD 2240 and 2610.

    Key words: Solar physics (celestial mechanics

  4. Analysis of in vitro and in vivo function of total knee replacements using dynamic contact models

    Science.gov (United States)

    Zhao, Dong

    Despite the high incidence of osteoarthritis in human knee joint, its causes remain unknown. Total knee replacement (TKR) has been shown clinically to be effective in restoring the knee function. However, wear of ultra-high molecular weight polyethylene has limited the longevity of TKRs. To address these important issues, it is necessary to investigate the in vitro and in vivo function of total knee replacements using dynamic contact models. A multibody dynamic model of an AMTI knee simulator was developed. Incorporating a wear prediction model into the contact model based on elastic foundation theory enables the contact surface to take into account creep and wear during the dynamic simulation. Comparisons of the predicted damage depth, area, and volume lost with worn retrievals from a physical machine were made to validate the model. In vivo tibial force distributions during dynamic and high flexion activities were investigated using the dynamic contact model. In vivo medial and lateral contact forces experienced by a well-aligned instrumented knee implant, as well as upper and lower bounds on contact pressures for a variety of activities were studied. For all activities, the predicted medial and lateral contact forces were insensitive to the selected material model. For this patient, the load split during the mid-stance phase of gait and during stair is more equal than anticipated. The external knee adduction torque has been proposed as a surrogate measure for medial compartment load during gait. However, a direct link between these two quantities has not been demonstrated using in vivo measurement of medial compartment load. In vivo data collected from a subject with an instrumented knee implant were analyzed to evaluate this link. The subject performed five different overground gait motions (normal, fast, slow, wide, and toe out) while instrumented implant, video motion, and ground reaction data were simultaneously collected. The high correlation coefficient

  5. A bio-inspired test system for bionic above-knee prosthetic knees

    Science.gov (United States)

    Wang, Dai-Hua; Xu, Lei; Fu, Qiang; Yuan, Gang

    2013-04-01

    Recently, prosthetic knees in the developing stage are usually tested by installing them on amputees' stumps directly or on above-knee prostheses (AKPs) test platforms. Although amputees can fully provide the actual motion state of the thigh, immature prosthetic knees may hurt amputees. For AKPs test platforms, it just can partly simulate the actual motion state of the thigh with limitation of the motion curve of the thigh, the merits or demerits of newly developed bionic above-knee prosthetic knees cannot be accessed thoroughly. Aiming at the defects of two testing methods, this paper presents a bio-inspired AKPs test system for bionic above-knee prosthetic knees. The proposed bio-inspired AKPs test system is composed of a AKPs test platform, a control system, and a bio-inspired system. The AKPs test platform generates the motion of the thigh simulation mechanism (TSM) via two screw pairs with servo motors. The bio-inspired system includes the tester and the bio-inspired sensor wore by the tester. The control system, which is inspired by the bio-inspired system, generates the control command signal to move the TSM of the AKPs test platform. The bio-inspired AKPs test system is developed and experimentally tested with a commercially available prosthetic knee. The research results show that the bio-inspired AKPs test system can not only ensure the safety of the testers, but also track all kinds of the actual motion state of the thigh of the testers in real time.

  6. An interferometric calibration system for various linear artefacts using active compensation of angular motion errors

    International Nuclear Information System (INIS)

    A calibration system for linear-dimension artefacts was developed, which employed a multi-axis laser interferometer for direct metrological traceability and active compensation of angular motion errors. It can calibrate various end and line standards by changing probes (contact and optical probe). We designed the system as a moving probe type with a cantilever structure to reduce overall size and increase efficiency in calibration. A stage part including a two-axis tilt stage provides precise linear motion of a probing part over the range of 2000 mm with nanometric resolution. The three-axis interferometer measuring linear and rotational motions of the stage enables us to obtain probing position and compensate angular motion errors precisely. It was also arranged to minimize the Abbe offset, and so the Abbe error can be reduced remarkably combining the active compensation of angular motion errors. The overall system was installed in a temperature-controlled chamber to decrease thermal variation during measurements. The measurement uncertainty of the calibration system was analysed by considering the performance of the main components. We measured several long gauge blocks and a precision line scale, and compared the measured values with the reference ones and also checked their stabilities. Their deviations were less than 100 nm and existed within the expanded measurement uncertainty (k = 2)

  7. Electroencephalogram evidence for mirror neuron activity during the observation of drawn hand motion

    Institute of Scientific and Technical Information of China (English)

    Huaping Zhu; Yaoru Sun; Wenya Duan

    2011-01-01

    The present study used electroencephalography to examine mu rhythm suppression (a putative index of human mirror neuron system activation) at frontal sites (F3, Fz and F4), central sites (C3, Cz and C4), parietal sites (P3, Pz and P4) and occipital sites (O1 and O2), while subjects observed real hand motion (real hand motion condition) and illustrative depictions of hand motion (drawn hand motion condition). Experimental data revealed that mu rhythm suppression was exhibited in the mirror neuron system when subjects observed both real and drawn hand motion. Moreover, the mu rhythm recorded at the F3, Fz, F4, and Pz poles was significantly suppressed while observing both stimulus types, but no obvious mu suppression occurred at the O1, O2 and O3 poles. These results suggest that the observation of drawings of human hand actions can activate the human mirror neuron system. This evidence supports the hypothesis that the mirror neuron system may be involved in intransitively abstract action understanding.

  8. Suspected feigned knee extensor weakness: usefulness of 3D gait analysis. Case report.

    Science.gov (United States)

    Chaler, Joaquim; Müller, Bertram; Maiques, Anna; Pujol, Eduard

    2010-07-01

    The purpose of the present case report is to show the potential for use of 3D gait analysis as an assessment method of feigned muscle weakness. We describe a patient complaining of right leg pain and weakness. Physical examination showed severe quadriceps muscle weakness in a highly abnormal gait pattern context. Conventional diagnostic workup did not show any relevant findings. Three-dimensional (3D) gait analysis was performed with a 3D motion capture system. Joint angles, internal moments and powers were computed from the motion data. Lower leg muscle surface-electromyography was also performed. During the late stance phase, flexor moment and negative power peaks (indicating eccentric knee extensor activity) were generated in the knee, together with relevant Rectus femoris activity. All findings were highly inconsistent with true quadriceps weakness and gave objective ground to suspect insincerity of patient complaints. 3D gait analysis might be a valuable clinical assessment tool in suspected feigned lower limb muscle weakness.

  9. Complex Human Activity Recognition Using Smartphone and Wrist-Worn Motion Sensors.

    Science.gov (United States)

    Shoaib, Muhammad; Bosch, Stephan; Incel, Ozlem Durmaz; Scholten, Hans; Havinga, Paul J M

    2016-03-24

    The position of on-body motion sensors plays an important role in human activity recognition. Most often, mobile phone sensors at the trouser pocket or an equivalent position are used for this purpose. However, this position is not suitable for recognizing activities that involve hand gestures, such as smoking, eating, drinking coffee and giving a talk. To recognize such activities, wrist-worn motion sensors are used. However, these two positions are mainly used in isolation. To use richer context information, we evaluate three motion sensors (accelerometer, gyroscope and linear acceleration sensor) at both wrist and pocket positions. Using three classifiers, we show that the combination of these two positions outperforms the wrist position alone, mainly at smaller segmentation windows. Another problem is that less-repetitive activities, such as smoking, eating, giving a talk and drinking coffee, cannot be recognized easily at smaller segmentation windows unlike repetitive activities, like walking, jogging and biking. For this purpose, we evaluate the effect of seven window sizes (2-30 s) on thirteen activities and show how increasing window size affects these various activities in different ways. We also propose various optimizations to further improve the recognition of these activities. For reproducibility, we make our dataset publicly available.

  10. Complex Human Activity Recognition Using Smartphone and Wrist-Worn Motion Sensors.

    Science.gov (United States)

    Shoaib, Muhammad; Bosch, Stephan; Incel, Ozlem Durmaz; Scholten, Hans; Havinga, Paul J M

    2016-01-01

    The position of on-body motion sensors plays an important role in human activity recognition. Most often, mobile phone sensors at the trouser pocket or an equivalent position are used for this purpose. However, this position is not suitable for recognizing activities that involve hand gestures, such as smoking, eating, drinking coffee and giving a talk. To recognize such activities, wrist-worn motion sensors are used. However, these two positions are mainly used in isolation. To use richer context information, we evaluate three motion sensors (accelerometer, gyroscope and linear acceleration sensor) at both wrist and pocket positions. Using three classifiers, we show that the combination of these two positions outperforms the wrist position alone, mainly at smaller segmentation windows. Another problem is that less-repetitive activities, such as smoking, eating, giving a talk and drinking coffee, cannot be recognized easily at smaller segmentation windows unlike repetitive activities, like walking, jogging and biking. For this purpose, we evaluate the effect of seven window sizes (2-30 s) on thirteen activities and show how increasing window size affects these various activities in different ways. We also propose various optimizations to further improve the recognition of these activities. For reproducibility, we make our dataset publicly available. PMID:27023543

  11. Population activity in the human dorsal pathway predicts the accuracy of visual motion detection

    NARCIS (Netherlands)

    Donner, T.H.; Siegel, M.; Oostenveld, R.; Fries, P.; Bauer, M.; Engel, A.K.

    2007-01-01

    A person's ability to detect a weak visual target stimulus varies from one viewing to the next. We tested whether the trial-to-trial fluctuations of neural population activity in the human brain are related to the fluctuations of behavioral performance in a "yes-no" visual motion-detection task. We

  12. Prospective Study of the Relation between Landing Biomechanics and Jumper's Knee

    NARCIS (Netherlands)

    van der Worp, H.; van der Does, H. T. D.; Brink, M. S.; Zwerver, J.; Hijmans, J. M.

    2016-01-01

    The literature on the relation between jump biomechanics and jumper's knee indicates that a jump with horizontal displacement poses a threat for developing jumper's knee. Subjects with jumper's knee have been shown to display a stiff landing pattern characterized by a small range of motion. However,

  13. Biomechanical Analysis of the Effects of Bilateral Hinged Knee Bracing

    Science.gov (United States)

    Lee, Hangil; Ha, Dokyeong; Kang, Yeoun-Seung; Park, Hyung-Soon

    2016-01-01

    This research analyzed the effect of bilateral hinged knee braces on a healthy knee from a biomechanical frame in vivo. This was accomplished by fitting a knee brace with two customized wireless force/torque (F/T) sensors that could readily record force and torque during live motion, while the kinetics at the knee were computed using the inverse dynamics of the motion capture and force plate data. Four tasks to test the brace’s effects were drop vertical jumping, pivoting, stop vertical jumping, and cutting. The results showed that the hinges in the knee brace can absorb up to 18% of the force and 2.7% of the torque at the knee during various athletic motions. Thus, the hinges demonstrated minimal effect in reducing the mechanical load on the knee. There were limitations concerning the consistency of the motions performed by the subjects during the trials and the influence of the other portions of the brace to evaluate the overall effectiveness of the brace as a whole. Future works may incorporate a fatigue protocol and injured subjects to better determine the effects of the brace. There is still a need for more research on the biomechanical influence of knee braces to develop safer and more effective products. PMID:27379233

  14. How crouch gait can dynamically induce stiff-knee gait.

    Science.gov (United States)

    van der Krogt, Marjolein M; Bregman, Daan J J; Wisse, Martijn; Doorenbosch, Caroline A M; Harlaar, Jaap; Collins, Steven H

    2010-04-01

    Children with cerebral palsy frequently experience foot dragging and tripping during walking due to a lack of adequate knee flexion in swing (stiff-knee gait). Stiff-knee gait is often accompanied by an overly flexed knee during stance (crouch gait). Studies on stiff-knee gait have mostly focused on excessive knee muscle activity during (pre)swing, but the passive dynamics of the limbs may also have an important effect. To examine the effects of a crouched posture on swing knee flexion, we developed a forward-dynamic model of human walking with a passive swing knee, capable of stable cyclic walking for a range of stance knee crouch angles. As crouch angle during stance was increased, the knee naturally flexed much less during swing, resulting in a 'stiff-knee' gait pattern and reduced foot clearance. Reduced swing knee flexion was primarily due to altered gravitational moments around the joints during initial swing. We also considered the effects of increased push-off strength and swing hip flexion torque, which both increased swing knee flexion, but the effect of crouch angle was dominant. These findings demonstrate that decreased knee flexion during swing can occur purely as the dynamical result of crouch, rather than from altered muscle function or pathoneurological control alone.

  15. Motional Stark Effect and Its Active Cancellation in Diamagnetic Spectrum of Barium

    Institute of Scientific and Technical Information of China (English)

    QUAN Wei; LIU Hong-Ping; SHEN Li; ZHAN Ming-Sheng

    2007-01-01

    With time-of-flight and electric field ionization detection technique, we investigate the motional Stark effect for highly excited Rydberg barium in high magnetic field and its active cancellation experimentally. In the experiment, the atom beam is aligned at a small angle of 15° with respect to the magnetic field. The motional Stark effect cancellation is demonstrated on two sets of circularly polarized spectra in static magnetic field B = 1.00000 Tesla and B = 1.70000 Tesla, respectively, although the effect is very small (~ 3.5 Vcm-1) in our apparatus configuration.

  16. Active contour-based visual tracking by integrating colors, shapes, and motions.

    Science.gov (United States)

    Hu, Weiming; Zhou, Xue; Li, Wei; Luo, Wenhan; Zhang, Xiaoqin; Maybank, Stephen

    2013-05-01

    In this paper, we present a framework for active contour-based visual tracking using level sets. The main components of our framework include contour-based tracking initialization, color-based contour evolution, adaptive shape-based contour evolution for non-periodic motions, dynamic shape-based contour evolution for periodic motions, and the handling of abrupt motions. For the initialization of contour-based tracking, we develop an optical flow-based algorithm for automatically initializing contours at the first frame. For the color-based contour evolution, Markov random field theory is used to measure correlations between values of neighboring pixels for posterior probability estimation. For adaptive shape-based contour evolution, the global shape information and the local color information are combined to hierarchically evolve the contour, and a flexible shape updating model is constructed. For the dynamic shape-based contour evolution, a shape mode transition matrix is learnt to characterize the temporal correlations of object shapes. For the handling of abrupt motions, particle swarm optimization is adopted to capture the global motion which is applied to the contour in the current frame to produce an initial contour in the next frame. PMID:23288333

  17. On the relationship between photospheric footpoint motions and coronal heating in solar active regions

    International Nuclear Information System (INIS)

    Coronal heating theories can be classified as either direct current (DC) or alternating current (AC) mechanisms, depending on whether the coronal magnetic field responds quasi-statically or dynamically to the photospheric footpoint motions. In this paper we investigate whether photospheric footpoint motions with velocities of 1-2 km s–1 can heat the corona in active regions, and whether the corona responds quasi-statically or dynamically to such motions (DC versus AC heating). We construct three-dimensional magnetohydrodynamic models for the Alfvén waves and quasi-static perturbations generated within a coronal loop. We find that in models where the effects of the lower atmosphere are neglected, the corona responds quasi-statically to the footpoint motions (DC heating), but the energy flux into the corona is too low compared to observational requirements. In more realistic models that include the lower atmosphere, the corona responds more dynamically to the footpoint motions (AC heating) and the predicted heating rates due to Alfvén wave turbulence are sufficient to explain the observed hot loops. The higher heating rates are due to the amplification of Alfvén waves in the lower atmosphere. We conclude that magnetic braiding is a highly dynamic process.

  18. Septic arthritis of the knee following anterior cruciate ligament reconstruction

    Directory of Open Access Journals (Sweden)

    Matjaz Sajovic

    2009-04-01

    Full Text Available Septic arthritis of the knee is a rare complication after arthroscopic anterior cruciate ligament reconstruction, and the most appropriate treatment is unclear. All case series reported so far have been retrospective, and case numbers of septic arthritis have ranged from 4 to 11. From a consecutive case series of 1,283 patients who underwent arthroscopic anterior cruciate ligament reconstruction between January 1997 and May 2008, we report on 3 patients (0.23% with post-operative septic arthritis. All patients had acute infection (≤ 2 weeks, bacterial cultures showed Staphylococcus species in 2 patients, while the bacterial culture was negative in the third. All of them underwent immediate arthroscopic debridement and lavage with continuous irrigation, as well as antibiotic treatment. The results were evaluated with physical and radiographic examination, functional testing, KT-2000, Lysholm and Tegner scales. The infection was successfully eradicated without further surgical treatment and the ligament graft was retained in all patients. Follow-up, at an average of 33 months, revealed that the patients had full symmetric knee range of motion and no effusion. The average Lysholm score was 91 points. In the patient with a lower subjective score, radiographs demonstrated patellofemoral joint-space narrowing, which is most probably in correlation with his anterior knee pain problems and lower activity level. The 134 N KT-2000 arthrometer side-to-side differences averaged 13 mm. Their performance in the single-legged hop test gave excellent results. The goals of treatment for septic arthritis after anterior cruciate ligament reconstruction are, primarily, to protect the articular cartilage and, secondly, to protect the graft. Through early diagnosis and prompt treatment, the infection can be successfully eradicated, with stability of the knee and full range of motion achieved.

  19. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong, E-mail: ouyang.jinsong@mgh.harvard.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Ackerman, Jerome L. [Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Petibon, Yoann [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2014-04-15

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic{sup 18}F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R{sup 2} = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.

  20. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    International Nuclear Information System (INIS)

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast

  1. Isokinetic and isometric muscle function of the knee extensors and flexors during simulated soccer activity: effect of exercise and dehydration.

    Science.gov (United States)

    Ali, Ajmol; Williams, Clyde

    2013-01-01

    This study investigated the influence of dehydration during soccer-type intermittent exercise on isokinetic and isometric muscle function. Eight soccer players performed two 90-min high-intensity intermittent shuttle-running trials without (NF) or with (FL) fluid ingestion (5 ml · kg(-1) before and 2 ml · kg(-1) every 15 min). Isokinetic and isometric strength and muscular power of knee flexors and knee extensors were measured pre-exercise, at half-time and post-exercise using isokinetic dynamometry. Sprint performance was monitored throughout the simulated-soccer exercise. Isokinetic knee strength was reduced at faster (3.13 rad · s(-1); P = 0.009) but not slower (1.05 rad · s(-1); P = 0.063) contraction speeds with exercise; however, there was no difference between FL and NF. Peak isometric strength of the knee extensors (P = 0.002) but not the knee flexors (P = 0.065) was significantly reduced with exercise with no difference between FL and NF. Average muscular power was reduced over time at both 1.05 rad · s(-1) (P = 0.01) and 3.14 rad · s(-1) (P = 0.033) but was not different between FL and NF. Mean 15-m sprint time increased with duration of exercise (P = 0.005) but was not different between FL and NF. In summary, fluid ingestion during 90 min of soccer-type exercise was unable to offset the reduction in isokinetic and isometric strength and muscular power of the knee extensors and flexors.

  2. Influence of patellofemoral bracing on pain, knee extensor torque, and gait function in females with patellofemoral pain.

    Science.gov (United States)

    Powers, Christopher M; Doubleday, Kathryn L; Escudero, Carina

    2008-01-01

    Our purpose was to evaluate the effects of a patellofemoral brace on pain response, knee extensor torque production, and gait function in females with patellofemoral pain (PFP). Sixteen females between the ages of 14 and 46 with diagnosis of PFP participated. Knee extensor torque was measured by using a LIDO isokinetic dynamometer. Pain levels were documented by using the Visual Analog Pain Scale. Stride characteristics during the conditions of free walk, fast walk, ascend stairs, descend stairs, ascend ramp, and descend ramp were obtained with a stride analyzer unit. EMG activity of the vasti musculature was recorded by using indwelling, bipolar, wire electrodes. Knee joint motion was assessed by using a VICON motion analysis system. All testing was performed with and without the Bauerfeind Genutrain P3 patellofemoral brace. There were no significant differences in torque production, pain levels, and stride characteristics between braced and non-braced trials. In addition, there were no significant differences in mean vasti EMG between braced and non-braced trials. When averaged across all conditions, a small but statistically significant increase in knee flexion was found during the braced trials. Although the current study did not find significant improvements in the clinical measures evaluated, 8 of the 16 subjects did experience a decrease in knee pain. This finding suggests that certain patients with PFP may respond favorably to bracing, and criteria must be established to determine which patients would best benefit from such an intervention.

  3. 持续被动运动对兔膝关节损伤后侧副韧带内弹性蛋白表达的影响%Continuous passive motion had an influence on elastic protein expression in deputy ligament after rabbits’ knee injury

    Institute of Scientific and Technical Information of China (English)

    孙青青; 周爱萍

    2015-01-01

    目的:观察持续被动运动( continuous passive motion,CPM)对兔膝关节损伤后侧副韧带内弹性蛋白的影响。方法选取15只新西兰雄性大白兔造膝关节软骨全层缺损模型,术后按运动方式不同,随机分成3组即制动组、自由活动组, CPM组。6周后提取韧带采用蛋白免疫印迹法( western blotting)进行弹性蛋白的检测。结果制动组的膝关节出现不同程度的僵硬,功能出现障碍;三组弹性蛋白的表达量分别是制动组(0.84±0.25)、自由活动组(2.91±0.34)、CPM组(2.04±0.69)。自由活动组侧副韧带内弹性蛋白的表达高于制动组和CPM组,CPM组侧副韧带内弹性蛋白的表达高于制动组,差异均有统计学意义(P<0.01)。结论 CPM和自由活动均可有效防止关节损伤后导致的韧带挛缩及关节僵硬,而自由活动效果更好。%Objective Observe the influence of elastin in the deputy ligament of rabbit whose knee joint were injury after con-tinuous passive motion.Methods 15 male New Zealand rabbits were used to establish the model of knee joint cartilage full-thick-ness defect.Then according to different way of movement, all animals were randomly divided into 3 groups:brake group, free activity group, CPM group.Ligaments were extracted and the elastin was test by western blot.Results All rabbits’knee joint appeared stiff-ness in different degrees and functional bottleneck.The elastin expression of three groups are as follows:brake group (0.84 ±0.25), free activity group (2.91 ±0.34), CPM group (2.04 ±0.69).Elastin expression of the deputy ligament in free activity group was higher than the brake group and CPM group ( P<0.01) .Elastin expression of the deputy ligament in CPM group was higher than the brake group ( P<0.01 ) .Conclusion CPM and free activities could effectively prevent ligament contracture and stiffness of joint which is caused by joint damage, while free

  4. An improved OpenSim gait model with multiple degrees of freedom knee joint and knee ligaments.

    Science.gov (United States)

    Xu, Hang; Bloswick, Donald; Merryweather, Andrew

    2015-08-01

    Musculoskeletal models are widely used to investigate joint kinematics and predict muscle force during gait. However, the knee is usually simplified as a one degree of freedom joint and knee ligaments are neglected. The aim of this study was to develop an OpenSim gait model with enhanced knee structures. The knee joint in this study included three rotations and three translations. The three knee rotations and mediolateral translation were independent, with proximodistal and anteroposterior translations occurring as a function of knee flexion/extension. Ten elastic elements described the geometrical and mechanical properties of the anterior and posterior cruciate ligaments (ACL and PCL), and the medial and lateral collateral ligaments (MCL and LCL). The three independent knee rotations were evaluated using OpenSim to observe ligament function. The results showed that the anterior and posterior bundles of ACL and PCL (aACL, pACL and aPCL, pPCL) intersected during knee flexion. The aACL and pACL mainly provided force during knee flexion and adduction, respectively. The aPCL was slack throughout the range of three knee rotations; however, the pPCL was utilised for knee abduction and internal rotation. The LCL was employed for knee adduction and rotation, but was slack beyond 20° of knee flexion. The MCL bundles were mainly used during knee adduction and external rotation. All these results suggest that the functions of knee ligaments in this model approximated the behaviour of the physical knee and the enhanced knee structures can improve the ability to investigate knee joint biomechanics during various gait activities. PMID:24611807

  5. Examining the Magnetic Field Strength and the Horizontal and Vertical Motions in an Emerging Active Region

    CERN Document Server

    Lin, Chia-Hsien

    2016-01-01

    Earlier observational studies have used the time evolution of emerging magnetic flux regions at the photosphere to infer their subsurface structures, assuming that the flux structure does not change significantly over the near-surface layer.In this study, we test the validity of this assumption by comparing the horizontal and vertical motions of an emerging active region. The two motions would be correlated if the emerging structure is rigid. The selected active region (AR) NOAA 11645 is not embedded in detectable preexisting magnetic field. The observed horizontal motion is quantified by the separation of the two AR polarities and the extension of the region. The vertical motion is derived from the magnetic buoyancy theory. Our results show that the separation of the polarities is fastest at the beginning with a velocity of $\\approx$~4~Mm hr$^{-1}$ and decreases to $\\le$~1~Mm hr$^{-1}$ after the main growing phase of flux emergence. The derived thick flux-tube buoyant velocity is between 1 and 3~Mm hr$^{-1}$...

  6. Knee osteoarthritis therapy through traditional Chinese herb smoking%中药薰洗治疗膝关节骨性关节炎

    Institute of Scientific and Technical Information of China (English)

    徐振奇; 姜贵云; 刘旭东; 柴叶红; 李青

    2003-01-01

    @@ INTRODUCTION Knee osteoarthritis is a regenerated change of knee hyaline cartilage, complicated with bone hyperplasia,synovitis and articular capsule and muscle changes due to old age and knee joint injury, deformity and diseases etc factors.Osteoarthritis induced many clinical manifestations including knee ache,swelling and limited motion and seriously affected the quality of the patients'.

  7. Biocatalyst activity in nonaqueous environments correlates with centisecond-range protein motions.

    Science.gov (United States)

    Eppler, Ross K; Hudson, Elton P; Chase, Shannon D; Dordick, Jonathan S; Reimer, Jeffrey A; Clark, Douglas S

    2008-10-14

    Recent studies exploring the relationship between enzymatic catalysis and protein dynamics in the aqueous phase have yielded evidence that dynamics and enzyme activity are strongly correlated. Given that protein dynamics are significantly attenuated in organic solvents and that proteins exhibit a wide range of motions depending on the specific solvent environment, the nonaqueous milieu provides a unique opportunity to examine the role of protein dynamics in enzyme activity. Variable-temperature kinetic measurements, X-band electron spin resonance spectroscopy, (1)H NMR relaxation, and (19)F NMR spectroscopy experiments were performed on subtilisin Carlsberg colyophilized with several inorganic salts and suspended in organic solvents. The results indicate that salt activation induces a greater degree of transition-state flexibility, reflected by a more positive DeltaDeltaS(dagger), for the more active biocatalyst preparations in organic solvents. In contrast, DeltaDeltaH(dagger) was negligible regardless of salt type or salt content. Electron spin resonance spectroscopy and (1)H NMR relaxation measurements, including spin-lattice relaxation, spin-lattice relaxation in the rotating frame, and longitudinal magnetization exchange, revealed that the enzyme's turnover number (k(cat)) was strongly correlated with protein motions in the centisecond time regime, weakly correlated with protein motions in the millisecond regime, and uncorrelated with protein motions on the piconanosecond timescale. In addition, (19)F chemical shift measurements and hyperfine tensor measurements of biocatalyst formulations inhibited with 4-fluorobenzenesulfonyl fluoride and 4-ethoxyfluorophosphinyl-oxy-TEMPO, respectively, suggest that enzyme activation was only weakly affected by changes in active-site polarity. PMID:18840689

  8. Knee Pain and the Weekend Warriors

    Medline Plus

    Full Text Available ... the knee with minimal interference in the patient’s life. What ’m doing right now is I’m ... this particular patient was extremely active throughout his life, he probably puts into his knee around five ...

  9. Functional calibration procedure for 3D knee joint angle description using inertial sensors.

    Science.gov (United States)

    Favre, J; Aissaoui, R; Jolles, B M; de Guise, J A; Aminian, K

    2009-10-16

    Measurement of three-dimensional (3D) knee joint angle outside a laboratory is of benefit in clinical examination and therapeutic treatment comparison. Although several motion capture devices exist, there is a need for an ambulatory system that could be used in routine practice. Up-to-date, inertial measurement units (IMUs) have proven to be suitable for unconstrained measurement of knee joint differential orientation. Nevertheless, this differential orientation should be converted into three reliable and clinically interpretable angles. Thus, the aim of this study was to propose a new calibration procedure adapted for the joint coordinate system (JCS), which required only IMUs data. The repeatability of the calibration procedure, as well as the errors in the measurement of 3D knee angle during gait in comparison to a reference system were assessed on eight healthy subjects. The new procedure relying on active and passive movements reported a high repeatability of the mean values (offset0.9). In comparison to the reference system, this functional procedure showed high precision (SD0.75) and moderate accuracy (between 4.0 degrees and 8.1 degrees) for the three knee angle. The combination of the inertial-based system with the functional calibration procedure proposed here resulted in a promising tool for the measurement of 3D knee joint angle. Moreover, this method could be adapted to measure other complex joint, such as ankle or elbow.

  10. 具有双屈伸运动人工半膝关节假体运动参数分析及实验性临床研究%Motion parameters analysis and pilot clinical trials of the dual mobility hemi-knee artificial prosthesis

    Institute of Scientific and Technical Information of China (English)

    革军; 王臻; 刘鹏; 栗向东; 陈国景

    2012-01-01

    目的 针对儿童股骨下段恶性骨肿瘤的诸多治疗方法中存在的问题,本课题组首次提出具有双屈伸运动人工半膝关节(双动半膝关节)的概念,进行其运动轨迹规律及实验性临床研究.方法 以Mimics/Geomagic/Pro-E软件的设计路线为技术路线.基于成人膝关节标本的CT数据,利用数控铣床机加工制作双动半膝关节假体,进行体外实验研究其运动参数特点,最后进行实验性临床研究.结果 离体实验结果:股骨内侧髁屈曲面球心位移在正常膝关节组为(2.59±0.43)mm,双动半膝关节组为(2.22±0.52) mm,全膝关节组为(1.18±0.43) mm;股骨外侧髁屈曲面球心位移在正常膝关节组为(11.95±6.62) mm,双动半膝关节组为(11.25±6.19)mm,全膝关节组为(1.26±0.42) mm;相对胫骨最大旋转角度在正常膝关节组为13.17°±7.58°,双动半膝关节组为11.69°±6.49°,全膝关节组为5.40°±1.29°.完成探索性临床试验,术后患者恢复良好,效果满意.结论 运动参数分析证明双动半膝关节接近正常膝关节运动模式,双动半膝关节为治疗儿童股骨下段恶性肿瘤提供了全新的理念和思路,新型附丽概念和新型韧带附丽装置为膝关节韧带功能重建提出新的解决方案.%Objective Aim at the problems in the treatments of the children malignant bone tumor of distal femur,we put forward the concept of the dual mobility hemi-knee prosthesis and try to perform the motion parameters analysis and the pilot clinical trials.Methods Base on the CT data from samples of knee joint in adult,we adopted the Mimics/Geomagic/Pro-E software and computer numerical control milling machine technology to design and produce the dual mobility hemi-knee artificial prosthesis,and then motion parameters was analyzed in vitro test,and at last pilot clinical trial was performed.Results In vitro experiment showed that the displacement of the internal femoral condyle flexion facet center was (2

  11. Objective clinical performance outcome of total knee prostheses. A study of mobile bearing knees using fluoroscopy, electromyography and roentgenstereophotogrammetry

    OpenAIRE

    Garling, Eric Harald

    2008-01-01

    The aim of the thesis was to to assess with accurate and objective methods the function and fixation of total knee prostheses with special emphasis on mobile bearing total knee designs. The mobile bearing of a rotating platform design showed limited motion or no motion during a step-up task thereby nullifying the theoretical advantages of a mobile bearing prosthesis. Apatite coated implants show excellent mid-term Roentgen Stereophotogrammetric Analysis (RSA) results and offer some clinical a...

  12. Meridional motions of sunspots from 1947.9 to 1985.0. II - Latitude motions dependent on SPOT type and phase of the activity cycle

    Science.gov (United States)

    Lustig, G.; Hanslmeier, A.

    1987-01-01

    The dependence of the meridional motions of sunspots on sunspot-type and phase in the solar activity cycle for the time interval 1947.9-1985.0 is examined; this was done also with the sunspot data from the solar-observatory Kanzelhoehe. For the total time interval, investigations for each cycle were carried out only for the elder or long lasting G, H, and J sunspot groups and distinctions between similar sunspot types AB, C, D, EF, GHJ (Zuerich-classification). The meridional motions about the different activity maxima were also examined. In all investigations in the period from 1947.9 to 1985.0 a tendency to a southdrift can be observed on both hemispheres of the sun, but the mean meridional motions are between the error-bars not very significantly different from zero.

  13. Knees Lifted High

    Centers for Disease Control (CDC) Podcasts

    2008-08-04

    The Eagle Books are a series of four books that are brought to life by wise animal characters - Mr. Eagle, Miss Rabbit, and Coyote - who engage Rain That Dances and his young friends in the joy of physical activity, eating healthy foods, and learning from their elders about health and diabetes prevention. Knees Lifted High gives children fun ideas for active outdoor play.  Created: 8/4/2008 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 8/5/2008.

  14. Stiffness after total knee arthroplasty.

    Science.gov (United States)

    Manrique, Jorge; Gomez, Miguel M; Parvizi, Javad

    2015-04-01

    Stiffness after total knee arthroplasty (TKA) adversely affects outcome and impacts patient function. Various risk factors for stiffness after TKA have been identified, including reduced preoperative knee range of motion, history of prior knee surgery, etiology of arthritis, incorrect positioning or oversizing of components, and incorrect gap balancing. Mechanical and associated causes, such as infection, arthrofibrosis, complex regional pain syndrome, and heterotopic ossification, secondary gain issues have also been identified. Management of stiffness following TKA can be challenging. The condition needs to be assessed and treated in a staged manner. A nonsurgical approach is the first step. Manipulation under anesthesia may be considered within the first 3 months after the index TKA, if physical therapy fails to improve the range of motion. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopically or by open arthrotomy. If the cause of stiffness is deemed to be surgical error, such as component malpositioning, revision arthroplasty is indicated. The purpose of this article is to evaluate the various aspects of management of stiffness after TKA.

  15. Stiffness after total knee arthroplasty.

    Science.gov (United States)

    Manrique, Jorge; Gomez, Miguel M; Parvizi, Javad

    2015-04-01

    Stiffness after total knee arthroplasty (TKA) adversely affects outcome and impacts patient function. Various risk factors for stiffness after TKA have been identified, including reduced preoperative knee range of motion, history of prior knee surgery, etiology of arthritis, incorrect positioning or oversizing of components, and incorrect gap balancing. Mechanical and associated causes, such as infection, arthrofibrosis, complex regional pain syndrome, and heterotopic ossification, secondary gain issues have also been identified. Management of stiffness following TKA can be challenging. The condition needs to be assessed and treated in a staged manner. A nonsurgical approach is the first step. Manipulation under anesthesia may be considered within the first 3 months after the index TKA, if physical therapy fails to improve the range of motion. Beyond this point, consideration should be given to surgical intervention such as lysis of adhesions, either arthroscopically or by open arthrotomy. If the cause of stiffness is deemed to be surgical error, such as component malpositioning, revision arthroplasty is indicated. The purpose of this article is to evaluate the various aspects of management of stiffness after TKA. PMID:25513992

  16. Multiple-ligament injured knee

    Institute of Scientific and Technical Information of China (English)

    SUN Lei; NING Zhi-jie; ZHANG Hui; TIAN Min; NING Tin-min

    2006-01-01

    Objective: To explore the clinical characteristic of the multiple-ligament injured knee and evaluate the protocol,technique and outcome of treatment for the multipleligament injured knee.Methods: From October 2001 to March 2005, 9 knees with combined anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) tears in 9 patients were identified with clinical and arthroscopic examinations. Of them, 5 knees were combined with ruptures of posteromedial corner (PMC) and medial collateral ligament (MCL), 4 with disruptions of posterolateral corner ( PLC), 2 with popliteal vascular injuries and 1 with peroneal nerve injuries. Six patients were hospitalized in acute phase of trauma, 2 received repairs of popliteal artery and 4 had repairs of PMC and MCL. Reconstructions of ACL and PCL with autografts under arthroscope were performed in all patients at 4 to 10 weeks after trauma,including reconstruction of PLC with the posterior half of biceps femoris tendon tenodesis in 4 patients and reconstructions of PMC and MCL with femoral fascia in 1 patient.Results: No severe complications occurred at early stage after operation in the 9 patients. All of them were followed up for 10-39 months with an average of 23. 00 months ± 9.46 months. Lysholm score was 70-95 with an average of 85.00 ± 8.29. International Knee Documentation Committee (IKDC) score was from severely abnormal (Grade D) in 9 knees at initial examination to normal (Grade A) in 2 knees, nearly normal (Grade B ) in 6 knees and abnormal in 1 knee at the last follow-up. Of the 9 patients, 7 returned to the same activity level before injury and 2 were under the level.Conclusions: The multiple-ligament injured knee with severe instability is usually combined with other important structure damages. Therefore, careful assessment and treatment of the combined injuries are essential. Reconstructions of ACL and PCL under arthroscope, combined with repairs or reconstructions of the extraarticular ligaments

  17. Motion-base simulator results of advanced supersonic transport handling qualities with active controls

    Science.gov (United States)

    Feather, J. B.; Joshi, D. S.

    1981-01-01

    Handling qualities of the unaugmented advanced supersonic transport (AST) are deficient in the low-speed, landing approach regime. Consequently, improvement in handling with active control augmentation systems has been achieved using implicit model-following techniques. Extensive fixed-based simulator evaluations were used to validate these systems prior to tests with full motion and visual capabilities on a six-axis motion-base simulator (MBS). These tests compared the handling qualities of the unaugmented AST with several augmented configurations to ascertain the effectiveness of these systems. Cooper-Harper ratings, tracking errors, and control activity data from the MBS tests have been analyzed statistically. The results show the fully augmented AST handling qualities have been improved to an acceptable level.

  18. A kinematic comparison of alterations to knee and ankle angles from resting measures to active pedaling during a graded exercise protocol.

    Science.gov (United States)

    Peveler, Willard W; Shew, Brandy; Johnson, Samantha; Palmer, Thomas G

    2012-11-01

    Saddle height is one of the most researched areas of bike fit. The current accepted method for adjusting saddle height involves the use of a goniometer to adjust saddle height so that a knee angle between 25° and 35° is obtained. This measurement is taken while the cyclist maintains a static position with the pedal at the 6-o'-clock position. However, the act of pedaling is dynamic, and angles may alter during movement. The purpose of this study was to examine the alterations to knee and ankle angle occurring from static measures to active pedaling across intensities experienced by cyclists during a graded exercise protocol. Thirty-four recreational to highly trained cyclists were evaluated using 2D analysis of stationary position and 3 active levels (level 1, respiratory exchange ratio of 1.00, and max). Dependent measures were compared using repeated measures analysis of variance (p = 0.05). When examining the results, it is evident that significant alterations to pedal stroke occur from stationary measures to active pedaling and as intensity increases toward maximal. Plantar flexion increased when moving from stationary measures to active pedaling, which resulted in an increase in knee angle. Although still greater than stationary measures, less plantar flexion occurred at higher intensities when compared with lower intensity cycling. Less plantar flexion at higher intensities is most likely a result of application of a larger downward torque occurring because of greater power requirements at higher intensities. There appeared to be greater variability in angle when examining novice cyclists in relation to more experienced cyclists. Although stationary measures are where a bike fit session will begin, observation during the pedal cycle may be needed to fine-tune the riders' fit.

  19. Perioperative Rehabilitation Using a Knee Extension Device and Arthroscopic Debridement in the Treatment of Arthrofibrosis

    OpenAIRE

    Biggs-Kinzer, Angie; Murphy, Brian; Shelbourne, K. Donald; Urch, Scott

    2010-01-01

    Background: Arthrofibrosis is a postoperative complication of intra-articular knee surgery that can be difficult to treat. Evidence suggests that maximizing knee range of motion may improve outcomes in patients with arthrofibrosis who undergo arthroscopic debridement. Hypothesis: Patients who achieve greater knee range of motion will have better subjective scores. Study Design: Retrospective case series analysis. Methods: A review of records was performed for 33 patients with arthrofibrosis w...

  20. Outcomes of manipulation under anesthesia versus surgical management of combat-related arthrofibrosis of the knee.

    Science.gov (United States)

    Evans, Korboi N; Lewandowski, Louis; Pickett, Adam; Strauss, Joseph E; Gordon, Wade T

    2013-01-01

    The purpose of this study was to compare the outcomes of manipulation under anesthesia (MUA) to arthrolysis for combat-related arthrofibrosis. Sixty-one knees in 56 patients who underwent treatment for arthrofibrosis secondary to lower extremity trauma were reviewed. Knee range of motion preoperatively, postoperatively, and at follow-up was analyzed. The primary outcome measure was the difference in knee arc of motion between the two cohorts. Forty-one knees (67.2%) underwent MUA and 20 knees (32.8%) were managed operatively. There was no difference in the preoperative arc of motion. Knees that underwent MUA had significant improvements in arc of motion compared to knees that underwent arthrolysis (106.3° vs. 82.3°) at a follow-up of 2 years (p = .008). The complication rate was greater in knees that underwent arthrolysis (40%) compared to knees that underwent MUA (12.2%; p = .04). In conclusion, knees that underwent MUA demonstrated significant improvements in arc of motion at 2-year follow-up with fewer complications. PMID:23449053

  1. Radiological imaging of osteoarthritis of the knee

    International Nuclear Information System (INIS)

    Osteoarthritis is the most common degenerative age-related joint disease leading to typical degradation of articular cartilage with severe pain and limitation of joint motion. Although knee radiographs are widely considered as the gold standard for the assessment of knee osteoarthritis in clinical and scientific settings they increasingly have significant limitations in situations when resolution and assessment of cartilage is required. Analysis of osteoarthritis of the knee with conventional x-ray is associated with many technical limitations and is increasingly being replaced by high-quality assessment using magnetic resonance imaging (MRI) or sonography both in the clinical routine and scientific studies. Novel imaging modalities such as MRI or ultrasound enable in vivo visualization of the quality of the cartilaginous structure and bone as well as all articular and periarticular tissue. Therefore, the limitations of radiographs in assessment of knee osteoarthritis could be overcome by these techniques. This review article aims to provide insights into the most important radiological features of knee osteoarthritis and systematic visualization with different imaging approaches. The demographic development in western industrialized countries predicts an increase of ageing-related osteoarthritis of the knee for the next decades. A systematic radiological evaluation of patients with knee osteoarthritis includes the assessment of the periarticular soft tissue, cartilaginous thickness, cartilage volume, possible cartilage defects, the macromodular network of hyaline cartilage, bone marrow edema, menisci and articular ligaments. Modern imaging modalities, such as MRI and sonography allow the limitations of conventional radiography to be overcome and to visualize the knee structures in great detail to quantitatively assess the severity of knee osteoarthritis. (orig.)

  2. The use of active breathing control (ABC) to reduce margin for breathing motion

    International Nuclear Information System (INIS)

    Purpose: For tumors in the thorax and abdomen, reducing the treatment margin for organ motion due to breathing reduces the volume of normal tissues that will be irradiated. A higher dose can be delivered to the target, provided that the risk of marginal misses is not increased. To ensure safe margin reduction, we investigated the feasibility of using active breathing control (ABC) to temporarily immobilize the patient's breathing. Treatment planning and delivery can then be performed at identical ABC conditions with minimal margin for breathing motion. Methods and Materials: An ABC apparatus is constructed consisting of 2 pairs of flow monitor and scissor valve, 1 each to control the inspiration and expiration paths to the patient. The patient breathes through a mouth-piece connected to the ABC apparatus. The respiratory signal is processed continuously, using a personal computer that displays the changing lung volume in real-time. After the patient's breathing pattern becomes stable, the operator activates ABC at a preselected phase in the breathing cycle. Both valves are then closed to immobilize breathing motion. Breathing motion of 12 patients were held with ABC to examine their acceptance of the procedure. The feasibility of applying ABC for treatment was tested in 5 patients by acquiring volumetric scans with a spiral computed tomography (CT) scanner during active breath-hold. Two patients had Hodgkin's disease, 2 had metastatic liver cancer, and 1 had lung cancer. Two intrafraction ABC scans were acquired at the same respiratory phase near the end of normal or deep inspiration. An additional ABC scan near the end of normal expiration was acquired for 2 patients. The ABC scans were also repeated 1 week later for a Hodgkin's patient. In 1 liver patient, ABC scans were acquired at 7 different phases of the breathing cycle to facilitate examination of the liver motion associated with ventilation. Contours of the lungs and livers were outlined when applicable

  3. Outcome of total knee arthroplasty with insall burstein-11 prosthesis

    International Nuclear Information System (INIS)

    Patients with severe degenerative knee joint disease often require knee arthroplasty to reduce pain, improve stability and restore function. Insall Burstein II prosthesis is posteriorly stabilized condylar prosthesis, which provide posterior cruciate ligament substitution. It was designed to improve range of motion, stair climbing ability and to prevent posterior subluxation. Evaluate the functional outcome of total knee arthroplasty with IB II prosthesis and Evaluate the alignment of prosthetic components by radiological parameters and its correlation with functional outcome. Sixty knees of sixty patients were replaced by using Insall Burstein II prosthesis. Postoperative radiographs were evaluated for alignment of knee and prosthetic components by criteria selected from knee society roentogenographic evaluation system. Functional outcome was evaluated by rationale of knee society knee rating system. Prosthetic component was aligned in 93% and mal-alignment in 7% of the cases. There was significant improvement in functions core from mean score 33.83 +-15.5 to 59.5+-17.7 and knee score from 37 +- 12.5 to 76.4 +-2.2. Postoperative functional score was found correlated with alignment significantly. Conclusion: Total knee arthroplasty with I-B-II prosthesis is a safe durable and predictable procedure with proper surgical technique and expertise good alignment and satisfactory functional out come can be achieved. (author)

  4. Activity preferences, lifestyle modifications and re-injury fears influence longer-term quality of life in people with knee symptoms following anterior cruciate ligament reconstruction: a qualitative study

    Directory of Open Access Journals (Sweden)

    Stephanie R Filbay

    2016-04-01

    Full Text Available Questions: How do people with knee symptoms describe their quality of life and experiences 5 to 20 years after anterior cruciate ligament reconstruction (ACLR? What factors impact upon the quality of life of these people? Design: Qualitative study. Participants: Seventeen people with knee symptoms 5 to 20 years after ACLR and high (n = 8 or low (n = 9 quality of life scores were recruited from a cross-sectional study. Methods: Semi-structured telephone interviews were conducted and transcribed. The data obtained from the interventions underwent inductive coding and thematic analysis. Results: Four consistent themes emerged from the interviews as common determinants of quality of life following ACLR: physical activity preferences; lifestyle modifications; adaptation and acceptance; and fear of re-injury. All participants described the importance of maintaining a physically active lifestyle and the relationship between physical activity and quality of life. Participants who avoided sport or activity reported experiencing reduced quality of life. Participants who suppressed or overcame re-injury fears to continue sport participation described experiencing a satisfactory quality of life while taking part in sport despite knee symptoms. For some participants, resuming competitive sport resulted in subsequent knee trauma, anterior cruciate ligament re-rupture or progressive deterioration of knee function, with negative impacts on quality of life following sport cessation. Participants who enjoyed recreational exercise often adapted their lifestyle early after ACLR, while others described adapting their lifestyle at a later stage to accommodate knee impairments; this was associated with feelings of acceptance and satisfaction, irrespective of knee symptoms. Conclusion: Activity preferences, lifestyle modifications and fear of re-injury influenced quality of life in people with knee symptoms up to 20 years following ACLR. People with a preference

  5. The comparison of spinal curves and hip and ankle range of motions between old and young persons

    OpenAIRE

    Nodehi-Moghadam, Afsun; Taghipour, Morteza; Goghatin Alibazi, Razie; Baharlouei, Hamzeh

    2014-01-01

    Background: Falls have been strongly associated with decreased physical activity and impaired mobility. Reduced range of motion, as a consequence of muscle stiffness, has been indicated to assume a positive relationship to fall incidence. Also clinical observations suggest that maintaining the normal spinal curves is associated with the prevention of spinal, knee and hip disorders. Thus, the aim of this study was to compare hip and ankle range of motions and thoracic and lumbar curves between...

  6. The Use of the Matrix Method for the Study of Human Motion:Theory and Applications

    Institute of Scientific and Technical Information of China (English)

    Zong-Ming Li; Jesse A. Fisk; Savio L-Y. Woo

    2003-01-01

    Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.

  7. Prediction of near-field strong ground motions for scenario earthquakes on active fault

    Institute of Scientific and Technical Information of China (English)

    Wang Haiyun; Xie Lili; Tao Xiaxin; Li Jie

    2006-01-01

    A method to predict near-field strong ground motions for scenario earthquakes on active faults is proposed. First,macro-source parameters characterizing the entire source area, i.e., global source parameters, including fault length, fault width,rupture area, average slip on the fault plane, etc., are estimated by seismogeology survey, seismicity and seismic scaling laws.Second, slip distributions characterizing heterogeneity or roughness on the fault plane, i.e., local source parameters, are reproduced/evaluated by the hybrid slip model. Finally, the finite fault source model, developed from both the global and local source parameters, is combined with the stochastically synthetic technique of ground motion using the dynamic corner frequency based on seismology. The proposed method is applied to simulate the acceleration time histories on three base-rock stations during the 1994 Northridge earthquake. Comparisons between the predicted and recorded acceleration time histories show that the method is feasible and practicable.

  8. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    DEFF Research Database (Denmark)

    Holm, Bente; Kristensen, Morten T; Bencke, Jesper;

    2010-01-01

    To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA).......To examine whether changes in knee-extension strength and functional performance are related to knee swelling after total knee arthroplasty (TKA)....

  9. Partial knee replacement - slideshow

    Science.gov (United States)

    ... page: //medlineplus.gov/ency/presentations/100225.htm Partial knee replacement - series To use the sharing features on ... A.M. Editorial team. Related MedlinePlus Health Topics Knee Replacement A.D.A.M., Inc. is accredited ...

  10. Knee braces - unloading

    Science.gov (United States)

    ... most people talk about the arthritis in their knees, they are referring to a type of arthritis ... is caused by wear and tear inside your knee joints. Cartilage, the firm, rubbery tissue that cushions ...

  11. Knee joint replacement - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100088.htm Knee joint replacement - series To use the sharing features ... 4 out of 4 Normal anatomy Overview The knee is a complex joint. It contains the distal ...

  12. Total Knee Replacement

    Science.gov (United States)

    ... following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other ... to the final success of your surgery. To learn more about the full value of total knee ...

  13. Osteotomy of the knee

    Science.gov (United States)

    ... is not affected unless you have had a knee injury in the past. Osteotomy surgery works by shifting ... M. Editorial team. Related MedlinePlus Health Topics Arthritis Knee Injuries and Disorders Browse the Encyclopedia A.D.A. ...

  14. Anterior knee pain

    Science.gov (United States)

    Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... Collado H, Fredericson M. Patellofemoral pain syndrome. Clin Sports ... www.ncbi.nlm.nih.gov/pubmed/20610028 . De Carlo M, Armstrong ...

  15. Microprocessor prosthetic knees.

    Science.gov (United States)

    Berry, Dale

    2006-02-01

    This article traces the development of microprocessor prosthetic knees from early research in the 1970s to the present. Read about how microprocessor knees work, functional options, patient selection, and the future of this prosthetic.

  16. Arm position influences the activation patterns of trunk muscles during trunk range-of-motion movements.

    Science.gov (United States)

    Siu, Aaron; Schinkel-Ivy, Alison; Drake, Janessa Dm

    2016-10-01

    To understand the activation patterns of the trunk musculature, it is also important to consider the implications of adjacent structures such as the upper limbs, and the muscles that act to move the arms. This study investigated the effects of arm positions on the activation patterns and co-activation of the trunk musculature and muscles that move the arm during trunk range-of-motion movements (maximum trunk axial twist, flexion, and lateral bend). Fifteen males and fifteen females, asymptomatic for low back pain, performed maximum trunk range-of-motion movements, with three arm positions for axial twist (loose, crossed, abducted) and two positions for flexion and lateral bend (loose, crossed). Electromyographical data were collected for eight muscles bilaterally, and activation signals were cross-correlated between trunk muscles and the muscles that move the arms (upper trapezius, latissimus dorsi). Results revealed consistently greater muscle co-activation (higher cross-correlation coefficients) between the trunk muscles and upper trapezius for the abducted arm position during maximum trunk axial twist, while results for the latissimus dorsi-trunk pairings were more dependent on the specific trunk muscles (either abdominal or back) and latissimus dorsi muscle (either right or left side), as well as the range-of-motion movement. The findings of this study contribute to the understanding of interactions between the upper limbs and trunk, and highlight the influence of arm positions on the trunk musculature. In addition, the comparison of the present results to those of individuals with back or shoulder conditions may ultimately aid in elucidating underlying mechanisms or contributing factors to those conditions.

  17. Increased physical activity severely induces osteoarthritic changes in knee joints with papain induced sulfate-glycosaminoglycan depleted cartilage

    OpenAIRE

    Siebelt, M.; Groen, H.C.; Koelewijn, S. J.; de Blois, E.; Sandker, M.; Waarsing, J. H.; Müller, C.(Dr. Remeis-Sternwarte and ECAP, Universität Erlangen-Nürnberg, Sternwartstr. 7, 96049 , Bamberg, Germany); van Osch, G. J. V. M.; de Jong, M.; Weinans, H.H.

    2014-01-01

    Introduction Articular cartilage needs sulfated-glycosaminoglycans (sGAGs) to withstand high pressures while mechanically loaded. Chondrocyte sGAG synthesis is regulated by exposure to compressive forces. Moderate physical exercise is known to improve cartilage sGAG content and might protect against osteoarthritis (OA). This study investigated whether rat knee joints with sGAG depleted articular cartilage through papain injections might benefit from moderate exercise, or whether this increase...

  18. Low-level intermittent quadriceps activity during transcranial direct current stimulation facilitates knee extensor force-generating capacity.

    Science.gov (United States)

    Washabaugh, Edward P; Santos, Luciana; Claflin, Edward S; Krishnan, Chandramouli

    2016-08-01

    Anodal transcranial direct current stimulation (tDCS) is known to increase the force-generating capacity of the skeletal muscles. However, when tDCS is concurrently combined with a motor task, interference may occur that hinders tDCS effects. Here, we tested the interaction and time course of tDCS effects on force production when paired with a low-level force-matching task. Twenty-two subjects were randomized into two groups: tDCS-Matching and tDCS-Resting. Each group received tDCS and a sham stimulation, separated by one week. Maximal knee extensor and flexor torques were measured before and up to twenty-five minutes following the stimulation. The tDCS-Matching group produced greater knee extension torques relative to sham when compared with the tDCS-Resting group. There was no significant effect for knee flexion. This suggests that interference does not occur for force production tasks when tDCS is combined with a motor task. Rather, the task appears to aid and isolate the effects to the muscle groups involved in the task. PMID:27138643

  19. Bicompartmental knee arthroplasty

    OpenAIRE

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect o...

  20. Posterior knee pain

    OpenAIRE

    English, S.; Perret, D.

    2010-01-01

    Posterior knee pain is a common patient complaint. There are broad differential diagnoses of posterior knee pain ranging from common causes such as injury to the musculotendinous structures to less common causes such as osteochondroma. A precise understanding of knee anatomy, the physical examination, and of the differential diagnosis is needed to accurately evaluate and treat posterior knee pain. This article provides a review of the anatomy and important aspects of the history and physical ...

  1. Total Knee Arthroplasty in the Combined Contracture

    Directory of Open Access Journals (Sweden)

    O.J. Voskresensky

    2009-09-01

    Full Text Available We have offered modified access to a knee to work out a method for restoration of extensive apparatus of the knee. 91 patients with degenerative damages of the knee were under out su-pervision. All patients were differentiated in groups according to the form of access and pa-thology of the knee. At all stages of studying the following method of investigation were made: goniometry — for estimation of the knee functional condition; electroneiromyography — for reveling deficiency of muscular activity and determination of its kind. Patient's satisfac-tion by operation was defined by means of WOMAC scale subjective indexes. The received digital material was subjected to statistical processing. Thus, it has been proved that applica-tion of the modified access to a knee offered by us in total knee arthroplasty in patients with combined contracture in comparison with traditionally applied technologies of extensive ap-paratus releasing allows in short terms to restore the volume and force of movements in a knee that reduces time of rehabilitation and improves quality of patient's life

  2. Modeling meiotic chromosome pairing: nuclear envelope attachment, telomere-led active random motion, and anomalous diffusion

    Science.gov (United States)

    Marshall, Wallace F.; Fung, Jennifer C.

    2016-04-01

    The recognition and pairing of homologous chromosomes during meiosis is a complex physical and molecular process involving a combination of polymer dynamics and molecular recognition events. Two highly conserved features of meiotic chromosome behavior are the attachment of telomeres to the nuclear envelope and the active random motion of telomeres driven by their interaction with cytoskeletal motor proteins. Both of these features have been proposed to facilitate the process of homolog pairing, but exactly what role these features play in meiosis remains poorly understood. Here we investigate the roles of active motion and nuclear envelope tethering using a Brownian dynamics simulation in which meiotic chromosomes are represented by a Rouse polymer model subjected to tethering and active forces at the telomeres. We find that tethering telomeres to the nuclear envelope slows down pairing relative to the rates achieved by unattached chromosomes, but that randomly directed active forces applied to the telomeres speed up pairing dramatically in a manner that depends on the statistical properties of the telomere force fluctuations. The increased rate of initial pairing cannot be explained by stretching out of the chromosome conformation but instead seems to correlate with anomalous diffusion of sub-telomeric regions.

  3. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    International Nuclear Information System (INIS)

    Purpose: Extensive radiotherapy volumes for tumors of the chest are partly caused by interfractional organ motion. We evaluated the feasibility of respiratory observation tools using the active breathing control (ABC) system and the effect on breathing cycle regularity and reproducibility. Methods and Materials: Thirty-six patients with unresectable tumors of the chest were selected for evaluation of the ABC system. Computed tomography scans were performed at various respiratory phases starting at the same couch position without patient movement. Threshold levels were set at minimum and maximum volume during normal breathing cycles and at a volume defined as shallow breathing, reflecting the subjective maximal tolerable reduction of breath volume. To evaluate the extent of organ movement, 13 landmarks were considering using commercial software for image coregistration. In 4 patients, second examinations were performed during therapy. Results: Investigating the differences in a normal breathing cycle versus shallow breathing, a statistically significant reduction of respiratory motion in the upper, middle, and lower regions of the chest could be detected, representing potential movement reduction achieved through reduced breath volume. Evaluating interfraction reproducibility, the mean displacement ranged between 0.24 mm (chest wall/tracheal bifurcation) to 3.5 mm (diaphragm) for expiration and shallow breathing and 0.24 mm (chest wall) to 5.25 mm (diaphragm) for normal inspiration. Conclusions: By modifying regularity of the respiratory cycle through reduction of breath volume, a significant and reproducible reduction of chest and diaphragm motion is possible, enabling reduction of treatment planning margins

  4. Biomechanical analysis of stair descent in patients with knee osteoarthritis.

    Science.gov (United States)

    Igawa, Tatsuya; Katsuhira, Junji

    2014-05-01

    [Purpose] The purposes of this study were to investigate the lower extremity joint kinematics and kinetics of patients with the knee osteoarthritis (knee OA) during stair descent and clarify the biomechanical factors related to their difficulty in stair descent. [Subjects and Methods] Eight healthy elderly persons and four knee OA patients participated in this study. A 3-D motion analysis system and force plates were employed to measure lower extremity joint angles, ranges of motion, joint moments, joint powers, and ratios of contribution for the joint powers while descending stairs. [Results] Knee joint flexion angle, extension moment, and negative power during the early stance phase in the knee OA group were smaller than those in the healthy subjects group. However, no significant changes in these parameters in the ankle joint were observed between the two subject groups. [Conclusion] Knee OA patients could not use the knee joint to absorb impact during the early stance phase of stair descent. Hence, they might compensate for the roles played by the intact knee joint by mainly using ipsilateral ankle kinematics and kinetics.

  5. Respiratory Motion of The Heart and Positional Reproducibility Under Active Breathing Control

    International Nuclear Information System (INIS)

    Purpose: To reduce cardiotoxicity from breast radiotherapy (RT), innovative techniques are under investigation. Information about cardiac motion with respiration and positional reproducibility under active breathing control (ABC) is necessary to evaluate these techniques. Methods and Materials: Patients requiring loco-regional RT for breast cancer were scanned by computed tomography using an ABC device at various breath-hold states, before and during treatment. Ten patients were studied. For each patient, 12 datasets were analyzed. Mutual information-based regional rigid alignment was used to determine the magnitude and reproducibility of cardiac motion as a function of breathing state. For each scan session, motion was quantified by evaluating the displacement of a point along the left anterior descending artery (LAD) with respect to its position at end expiration. Long-term positional reproducibility was also assessed. Results: Displacement of the LAD was greatest in the inferior direction, moderate in the anterior direction, and lowest in the left-right direction. At shallow breathing states, the average displacement of LAD position was up to 6 mm in the inferior direction. The maximum displacement in any patient was 2.8 cm in the inferior direction, between expiration and deep-inspiration breath hold. At end expiration, the long-term reproducibility (SD) of the LAD position was 3 mm in the A-P, 6 mm in the S-I, and 4 mm in the L-R directions. At deep-inspiration breath hold, long-term reproducibility was 3 mm in the A-P, 7 mm in the S-I, and 3 mm in the L-R directions. Conclusions: These data demonstrate the extent of LAD displacement that occurs with shallow breathing and with deep-inspiration breath hold. This information may guide optimization studies considering the effects of respiratory motion and reproducibility of cardiac position on cardiac dose, both with and without ABC

  6. The use of active breathing control (ABC) to minimize breathing motion during radiation therapy

    International Nuclear Information System (INIS)

    Purpose. Reducing the treatment margin for organ motion during breathing reduces the volume of irradiated normal tissues. This may allow a higher dose of radiation to be delivered to the target volume for thoracic and abdominal tumors. However, such margin reduction must not increase the risk of marginal misses which may lead to local failure. In this study, we investigate the feasibility of using Active Breathing Control (ABC) to temporarily immobilize the patient's breathing. Planning CT scans and radiation delivery can then be performed at identical ABC conditions such that a minimal margin for breathing motion can be prescribed safely. Methods and Materials. An active breathing control (ABC) apparatus was constructed consisting of two pairs of flow monitor and scissors valve; one each to control the inhalation and exhalation paths to the patient. The patient breathed through a mouth-piece or face mask connected to the ABC apparatus. A personal computer was used to process the respiratory signal and to display the changing lung volume in real-time. At some time after the patient achieved a stable breathing pattern, the operator activated ABC at a pre-selected point in the breathing cycle. Both valves were then closed to immobilize breathing motion. The period of active breath-hold was that which could be comfortably and repeatedly tolerated by each individual patient, as determined during a training session. The feasibility of the ABC procedure was studied by acquiring volumetric CT scans of a patient during active breath-hold. A helical CT scanner was used. These ABC scans were acquired at one-half to one-third the dose delivered with routine CT scanning. Nine patients with tumors in the thorax and abdomen were studied. Contiguous CT slices were obtained for a region which encompassed the target volume. At least 4 sets of volumetric scans were obtained; one with the patient breathing normally; two ABC scans at the same point near the end of normal inspiration

  7. Fatigue Effects on Knee Joint Stability During Two Jump Tasks in Women

    OpenAIRE

    Ortiz, Alexis; Olson, Sharon L.; Etnyre, Bruce; Trudelle-Jackson, Elaine E.; Bartlett, William; Venegas-Rios, Heidi L.

    2010-01-01

    Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 ± 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak kne...

  8. Magnetic Resonance Imaging for Traumatic Knee Injury

    OpenAIRE

    Oei, Edwin

    2009-01-01

    textabstractTraumatic knee lesions are frequently encountered both in general practice and in the hospital setting. These injuries are often caused by sports and other physical activities and may lead to severe pain and disability.

  9. Knee Pain and the Weekend Warriors

    Medline Plus

    Full Text Available ... to the knee. Is that something related to exercise, lack of exercise? Is there anything that that an individual could ... while participating in weekend activities or sports? Well exercise is always good, but a meniscus tear itself ...

  10. Motion or activity: their role in intra- and inter-subject variation in fMRI

    DEFF Research Database (Denmark)

    Lund, Torben E; Nørgaard, Minna D; Rostrup, Egill;

    2005-01-01

    MRI to pre-surgical planning because of a higher requirement for intra-subject precision. The purpose of this study was to investigate the impact of residual movement artefacts on intra-subject and inter-subject variability in the observed fMRI activation. Ten subjects were examined using three different...... Linear Model (GLM). The data were analysed with and without modeling the residual movement artefacts and the impact on inter-session variance was assessed using F-contrasts. Inclusion of motion parameters in the analysis significantly reduced both the intra-subject as well as the inter-subject-variance...

  11. Active range of motion outcomes after reconstruction of burned wrist and hand deformities.

    Science.gov (United States)

    Afifi, Ahmed M; Mahboub, Tarek A; Ibrahim Fouad, Amr; Azari, Kodi; Khalil, Haitham H; McCarthy, James E

    2016-06-01

    This works aim is to evaluate the efficacy of skin grafts and flaps in reconstruction of post-burn hand and wrist deformities. A prospective study of 57 burn contractures of the wrist and dorsum of the hand was performed. Flaps were used only if there was a non-vascularized structure after contracture release, otherwise a skin graft was used. Active range of motion (ROM) was used to assess hand function. The extension deformity cohort uniformly underwent skin graft following contracture release with a mean improvement of 71 degrees (p6 months. Early release of burn contracture is advisable to avoid deep structure contracture.

  12. X-ray activity phased with planet motion in HD 189733?

    OpenAIRE

    Pillitteri, I.; Guenther, H. M.; Wolk, S. J.; Kashyap, V.; Cohen, O.

    2011-01-01

    We report on the follow-up XMM-Newton observation of the planet-hosting star HD 189733 we obtained in April 2011. We observe a flare just after the secondary transit of the hot Jupiter. This event shares the same phase and many of the characteristics of the flare we observed in 2009. We suggest that a systematic interaction between planet and stellar magnetic fields when the planet passes close to active regions on the star can lead to periodic variability phased with planetary motion. By mea...

  13. Extract the Relational Information of Static Features and Motion Features for Human Activities Recognition in Videos

    Science.gov (United States)

    2016-01-01

    Both static features and motion features have shown promising performance in human activities recognition task. However, the information included in these features is insufficient for complex human activities. In this paper, we propose extracting relational information of static features and motion features for human activities recognition. The videos are represented by a classical Bag-of-Word (BoW) model which is useful in many works. To get a compact and discriminative codebook with small dimension, we employ the divisive algorithm based on KL-divergence to reconstruct the codebook. After that, to further capture strong relational information, we construct a bipartite graph to model the relationship between words of different feature set. Then we use a k-way partition to create a new codebook in which similar words are getting together. With this new codebook, videos can be represented by a new BoW vector with strong relational information. Moreover, we propose a method to compute new clusters from the divisive algorithm's projective function. We test our work on the several datasets and obtain very promising results.

  14. Knee stability assessment on anterior cruciate ligament injury: Clinical and biomechanical approaches

    Directory of Open Access Journals (Sweden)

    Lam Mak-Ham

    2009-08-01

    Full Text Available Abstract Anterior cruciate ligament (ACL injury is common in knee joint accounting for 40% of sports injury. ACL injury leads to knee instability, therefore, understanding knee stability assessments would be useful for diagnosis of ACL injury, comparison between operation treatments and establishing return-to-sport standard. This article firstly introduces a management model for ACL injury and the contribution of knee stability assessment to the corresponding stages of the model. Secondly, standard clinical examination, intra-operative stability measurement and motion analysis for functional assessment are reviewed. Orthopaedic surgeons and scientists with related background are encouraged to understand knee biomechanics and stability assessment for ACL injury patients.

  15. Association of Cross Linked C-Telopeptide II Collagen and Hyaluronic Acid with Knee Osteoarthritis Severity

    Directory of Open Access Journals (Sweden)

    John Butar Butar

    2013-12-01

    Full Text Available BACKGROUND: This study was carried out to investigate the association of Cross Linked C-Telopeptide Type I & II Collagen (CTX-I and II and hyaluronic acid (HA with knee osteoarthritis (OA severity. METHODS: Sixty menopause women with primary knee OA were enrolled in this study during their visits to the Outpatient Department. Patients with knee pain during weight bearing, active or passive range of motion, or tenderness with Kellgren-Lawrence (KL grade of more than I were included. Patients with injury, inflammatory and metabolic diseases were excluded. Patients were put in a 10-hour fasting prior to withdrawal of morning blood samples for examinations of HA, CTX-I, interleukin 1 beta (IL-1β, and high sensitivity C reactive protein (hs-CRP level. Second void morning urine specimens were taken for CTXII assessment. HA, CTX-I and II levels were measured by enzyme-linked immunosorbent assay. RESULTS: Sixty menopausal female patients were included in this study, 35 with KL grade II, 17 grade III, and 8 grade IV. Means of CTX-II were significantly different between subjects KL grade IV and III (p=0.021. Correlation of KL grade was significant with CTX-II (p=0.001, r=0.412 and HA (p=0.0411, r=0.269. KL grades were not significantly associated with CTX-I (p=0.8364, r=-0.0272; IL-1β (p=0.5773, r=0.0853 and hs-CRP (p=0.2625, r=0.1470. CONCLUSIONS: CTX-II and HA were associated with severity of knee OA, suggesting that CTX-II and HA can be used as marker for knee OA severity. KEYWORDS: CTX-II, hyaluronic acid, otestoarthritis, knee.

  16. Experimental muscle pain during a forward lunge--the effects on knee joint dynamics and electromyographic activity

    DEFF Research Database (Denmark)

    Henriksen, Marius; Alkjaer, T; Simonsen, Erik Bruun;

    2009-01-01

    . Isotonic saline (0.9%) was used as control. MAIN OUTCOME MEASUREMENTS: Three-dimensional movement analyses were performed and inverse dynamics were used to calculate joint kinematics and kinetics for ankle, knee and hip joints. Electromyographic (EMG) signals of the hamstrings and quadriceps muscles were...... healthy subjects were included. One subject was excluded during data collection. INTERVENTION: The subjects performed forward lunges before, during and 20 minutes after induction of experimental quadriceps muscle pain. Muscle pain was induced using hypertonic saline (5.8%) injected intramuscularly...

  17. Perceived Direction of Self-Motion from Orthogonally Directed Visual and Vestibular Stimulation in Passive and Active Observation

    Directory of Open Access Journals (Sweden)

    Kenzo Sakurai

    2011-10-01

    Full Text Available Perceiving the direction of self-motion is typically a multisensory process. The most effective cue to detect the observer's heading direction is the visual optic-flow pattern. In the initial period of body movement, however, the vestibular sense is another effective cue to detect the direction in which one's body started to move. Here I report our recent research on the perception of self-motion, 1 when observers are passively experiencing their real somatic motion in different body posture, and 2 when observers are actively moving their bodies forward and backward. Previously, we reported that when upright observers passively experience real linear oscillatory somatic motion (leftward/rightward or forward/backward while viewing orthogonal visual optic flow patterns (translating or expanding/contracting, their perceived body motion direction is intermediate to those specified by visual and vestibular information individually (Sakurai et al., 2002, ACV; 2003, ECVP; Sakurai et al., 2010, VSS; Kubodera et al., 2010, APCV. We then generalized those findings exploring other visual/vestibular combinations, investigating when the vertical axis of body coordinates is orthogonal to the gravity axis. Observers lay supinely and reported their perceived direction of self-motion, experiencing real upward/downward or leftward/rightward motion in body coordinates, while viewing orthogonal optic-flow patterns that were phase-locked to the swing motion. The results are very similar to our previous reports, but for combinations of body motion with visual expanding/contracting optic-flow, some observers' judgments were vision-only or vestibular-only, suggesting that multimodal integration in this context is an either-or process for these observers. Compared to our previous reports, one possible reason for this weighted combination failure is the discrepancy between body coordinates and gravity coordinates (Sakurai et al., 2011, ECVP. We recently extended those

  18. Asymmetric varus and valgus stability of the anatomic cadaver knee and the load sharing between collateral ligaments and bearing surfaces.

    Science.gov (United States)

    Wang, Xiaonan; Malik, Aamer; Bartel, Donald L; Wickiewicz, Thomas L; Wright, Timothy

    2014-08-01

    Knee joint stability is important in maintaining normal joint motion during activities of daily living. Joint instability not only disrupts normal motion but also plays a crucial role in the initiation and progression of osteoarthritis. Our goal was to examine knee joint coronal plane stability under varus or valgus loading and to understand the relative contributions of the mechanisms that act to stabilize the knee in response to varus-valgus moments, namely, load distribution between the medial and lateral condyles and the ligaments. A robot testing system was used to determine joint stability in human cadaveric knees as described by the moment versus angular rotation behavior under varus and valgus loads at extension and at 30 deg and 90 deg of flexion. The anatomic knee joint was more stable in response to valgus than varus moments, and stability decreased with flexion angle. The primary mechanism for providing varus-valgus stability was the redistribution of the contact force on the articular surfaces from both condyles to a single condyle. Stretching of the collateral ligaments provided a secondary stabilizing mechanism after the lift-off of a condyle occurred. Compressive loads applied across the knee joint, such as would occur with the application of muscle forces, enhanced the ability of the articular surface to provide varus-valgus moment, and thus, helped stabilize the joint in the coronal plane. Coupled internal/external rotations and anteroposterior and medial-lateral translations were variable and in the case of the rotations were often as large as the varus-valgus rotations created by the applied moment.

  19. Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

    Science.gov (United States)

    Lowry, Michael; Rosenbaum, Heather; Walker, Peter S

    2016-05-01

    Mechanical evaluation of total knees is frequently required for aspects such as wear, strength, kinematics, contact areas, and force transmission. In order to carry out such tests, we developed a crouching simulator, based on the Oxford-type machine, with novel features including a synthetic knee including ligaments. The instrumentation and data processing methods enabled the determination of contact area locations and interface forces and moments, for a full flexion-extension cycle. To demonstrate the use of the simulator, we carried out a comparison of two different total knee designs, cruciate retaining and substituting. The first part of the study describes the simulator design and the methodology for testing the knees without requiring cadaveric knee specimens. The degrees of freedom of the anatomic hip and ankle joints were reproduced. Flexion-extension was obtained by changing quadriceps length, while variable hamstring forces were applied using springs. The knee joint was represented by three-dimensional printed blocks on to which the total knee components were fixed. Pretensioned elastomeric bands of realistic stiffnesses passed through holes in the block at anatomical locations to represent ligaments. Motion capture of the knees during flexion, together with laser scanning and computer modeling, was used to reconstruct contact areas on the bearing surfaces. A method was also developed for measuring tibial component interface forces and moments as a comparative assessment of fixation. The method involved interposing Tekscan pads at locations on the interface. Overall, the crouching machine and the methodology could be used for many different mechanical measurements of total knee designs, adapted especially for comparative or parametric studies. PMID:26802075

  20. Semi-active control of the rocking motion of monolithic art objects

    Science.gov (United States)

    Ceravolo, Rosario; Pecorelli, Marica Leonarda; Zanotti Fragonara, Luca

    2016-07-01

    The seismic behaviour of many art objects and obelisks can be analysed in the context of the seismic response of rigid blocks. Starting from the pioneering works by Housner, a large number of analytical studies of the rigid block dynamics were proposed. In fact, despite its apparent simplicity, the motion of a rigid block involves a number of complex dynamic phenomena such as impacts, sliding, uplift and geometric nonlinearities. While most of the current strategies to avoid toppling consist in preventing rocking motion, in this paper a novel semi-active on-off control strategy for protecting monolithic art objects was investigated. The control procedure under study follows a feedback-feedforward scheme that is realised by switching the stiffness of the anchorages located at the two lower corner of the block between two values. Overturning spectra have been calculated in order to clarify the benefits of applying a semi-active control instead of a passive control strategy. In accordance with similar studies, the numerical investigation took into account the dynamic response of blocks with different slenderness and size subject to one-sine pulse excitation.

  1. Effect of motion smoothness on brain activity while observing a dance: An fMRI study using a humanoid robot.

    Science.gov (United States)

    Miura, Naoki; Sugiura, Motoaki; Takahashi, Makoto; Sassa, Yuko; Miyamoto, Atsushi; Sato, Shigeru; Horie, Kaoru; Nakamura, Katsuki; Kawashima, Ryuta

    2010-01-01

    Motion smoothness is critical in transmitting implicit information of body action, such as aesthetic qualities in dance performances. We expected that the perception of motion smoothness would be characterized by great intersubject variability deriving from differences in personal backgrounds and attitudes toward expressive body actions. We used functional magnetic resonance imaging and a humanoid robot to investigate the effects of the motion smoothness of expressive body actions and the intersubject variability due to personal attitudes on perceptions during dance observation. The effect of motion smoothness was analyzed by both conventional subtraction analysis and functional connectivity analyses that detect cortical networks reflecting intersubject variability. The results showed that the cortical networks of motion- and body-sensitive visual areas showed increases in activity in areas corresponding with motion smoothness, but the intersubject variability of personal attitudes toward art did not influence these active areas. In contrast, activation of cortical networks, including the parieto-frontal network, has large intersubject variability, and this variability is associated with personal attitudes about the consciousness of art. Thus, our results suggest that activity in the cortical network involved in understanding action is influenced by personal attitudes about the consciousness of art during observations of expressive body actions.

  2. Efficacy of multimodal cocktail periarticular injection with or without steroid in total knee arthroplasty

    Institute of Scientific and Technical Information of China (English)

    YUE De-bo; WANG Bai-liang; LIU Kun-peng; GUO Wan-shou

    2013-01-01

    Background Multimodal cocktail periarticular injection (MCPI) with a large volume of low concentration local anesthetics,adrenaline,and anti-inflammatory agents such as non-steroidal anti-inflammatory drug or steroids have shown good pain control and improvement in range of motion after surgery.This study compares the efficacy of pain control after total knee arthroplasty,using multimodal cocktail periarticular injection with steroid or without steroid.Methods This is a prospective,double-blinded,randomized and control study.Seventy-two patients with osteoarthritis that met clinical criteria for total knee arthroplasty were recruited into the study,and were randomized to receive either multimodal cocktail periarticular injection with steroid or without steroid.Pain was assessed by visual analogue scale (VAS) at preoperative and postoperative at rest,and during activity.The range of motion was recorded preoperatively and postoperatively.The amount of daily and cumulative morphine consumption were measured by patient-controlled analgesia in the first 72 hours postoperatively.The duration of celecoxib usage was also recorded at the last follow-up.Results There were no differences between the non-steroid and steroid groups with regard to VAS at rest and during activity,or range of motion,at any postoperative observation time.The postoperative Knee Society Knee Score in the steroid group improved significantly as compared with that in non-steroid group at the one-month (84.1±13.1 and 65.9±12.1; P <0.0045),three-month follow-up (90.2±16.3 and 72.5±16.6; P <0.0027),but after postoperative six-month the Knee Society Knee Score showed no significant difference between the groups.There was no significant difference in consumption of the morphine about daily or total consumption within 72 hours between the two groups.The duration of celecoxib usage in patients in the steroid group was significantly shorter than that in the non-steroid group ((7.2±0.7) compared with

  3. Early recovery after fast-track Oxford unicompartmental knee arthroplasty

    DEFF Research Database (Denmark)

    Munk, Stig; Dalsgaard, Jesper; Bjerggaard, Karin;

    2012-01-01

    performance reached the preoperative level after 1 month. Only slight postoperative knee swelling was observed with rapid restoration of knee flexion and function. A high level of pain during the first postoperative night and day fell considerably thereafter. None of the patients needed physiotherapy...... supervision in the first month after discharge. Interpretation Fast-track MIS Oxford UKA with discharge on the day after surgery is safe and leads to early recovery of knee motion and strength even when no physiotherapy is used.......Background and purpose After total knee arthroplasty with conventional surgical approach, more than half of the quadriceps extension strength is lost in the first postoperative month. Unicompartmental knee arthroplasty (UKA) operated with minimally invasive surgery (MIS) results in less operative...

  4. Interpolation function for approximating knee joint behavior in human gait

    Science.gov (United States)

    Toth-Taşcǎu, Mirela; Pater, Flavius; Stoia, Dan Ioan

    2013-10-01

    Starting from the importance of analyzing the kinematic data of the lower limb in gait movement, especially the angular variation of the knee joint, the paper propose an approximation function that can be used for processing the correlation among a multitude of knee cycles. The approximation of the raw knee data was done by Lagrange polynomial interpolation on a signal acquired using Zebris Gait Analysis System. The signal used in approximation belongs to a typical subject extracted from a lot of ten investigated subjects, but the function domain of definition belongs to the entire group. The study of the knee joint kinematics plays an important role in understanding the kinematics of the gait, this articulation having the largest range of motion in whole joints, in gait. The study does not propose to find an approximation function for the adduction-abduction movement of the knee, this being considered a residual movement comparing to the flexion-extension.

  5. Anteroposterior glide versus rotating platform low contact stress (LCS knee arthroplasty: a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Wynn-Jones Charles

    2007-08-01

    Full Text Available Abstract Background Fifty thousand knee replacements are performed annually in the UK at an estimated cost of £150 million. Post-operative improvement depends on a number of factors including implant design and patient associated factors. To our knowledge there are no published study's comparing the results of AP glide and rotating platform designs of LCS knee arthroplasty. Therefore we feel that a study is required to investigate and compare the effects of two types of LCS total knee arthroplasty on joint proprioception and range of motion. Methods/Design Patients will be randomised to receive either a LCS AP glide or Rotating platform prosthesis. Clinical scores (Oxford knee score, American knee society score, EuroQol, range of motion and proprioception will be assessed prior to and at 3,6, 12 and 24 months after the operation. Proprioception will be assessed in terms of absolute error angle (mean difference between the target angle and the response angle. Knee angles will be measured in degrees using an electromagnetic tracking device, Polhemus 3Space Fastrak that detects positions of sensors placed on the test limb. Student's t-test will be used to compare the mean of two groups. Discussion Evidence is lacking concerning the best prosthesis to use for patients undergoing total knee replacement. This pragmatic randomised trial will test the null hypothesis that anteroposterior glide LCS knee arthroplasty does not result in better post operative knee motion and proprioception as compared to rotating platform LCS knee. Trial Registration ISRCTN52943804

  6. Real-time magnetic resonance imaging (MRI during active wrist motion--initial observations.

    Directory of Open Access Journals (Sweden)

    Robert D Boutin

    Full Text Available BACKGROUND: Non-invasive imaging techniques such as magnetic resonance imaging (MRI provide the ability to evaluate the complex anatomy of bone and soft tissues of the wrist without the use of ionizing radiation. Dynamic instability of wrist--occurring during joint motion--is a complex condition that has assumed increased importance in musculoskeletal medicine. The objective of this study was to develop an MRI protocol for evaluating the wrist during continuous active motion, to show that dynamic imaging of the wrist is realizable, and to demonstrate that the resulting anatomical images enable the measurement of metrics commonly evaluated for dynamic wrist instability. METHODS: A 3-Tesla "active-MRI" protocol was developed using a bSSFP sequence with 475 ms temporal resolution for continuous imaging of the moving wrist. Fifteen wrists of 10 asymptomatic volunteers were scanned during active supination/pronation, radial/ulnar deviation, "clenched-fist", and volarflexion/dorsiflexion maneuvers. Two physicians evaluated distal radioulnar joint (DRUJ congruity, extensor carpi ulnaris (ECU tendon translation, the scapholunate (SL interval, and the SL, radiolunate (RL and capitolunate (CL angles from the resulting images. RESULTS: The mean DRUJ subluxation ratio was 0.04 in supination, 0.10 in neutral, and 0.14 in pronation. The ECU tendon was subluxated or translated out of its groove in 3 wrists in pronation, 9 wrists in neutral, and 11 wrists in supination. The mean SL interval was 1.43 mm for neutral, ulnar deviation, radial deviation positions, and increased to 1.64 mm during the clenched-fist maneuver. Measurement of SL, RL and CL angles in neutral and dorsiflexion was also accomplished. CONCLUSION: This study demonstrates the initial performance of active-MRI, which may be useful in the investigation of dynamic wrist instability in vivo.

  7. Ambulatory activity monitoring: Progress in measurement of activity, posture, and specific motion patterns in daily life

    NARCIS (Netherlands)

    J.B.J. Bussmann (Hans); U.W. Ebner-Priemer (Ulrich); J. Fahrenberg (Jochen)

    2009-01-01

    textabstractBehavior is central to psychology in almost any definition. Although observable activity is a core aspect of behavior, assessment strategies have tended to focus on emotional, cognitive, or physiological responses. When physical activity is assessed, it is done so mostly with questionnai

  8. Development of a hinge compatible with the kinematics of the knee joint.

    Science.gov (United States)

    Bertomeu, José María Baydal; Lois, Juan Manuel Belda; Guillem, Ricard Barberà; Pozo, Alvaro Page Del; Lacuesta, Javiersanchez; Mollà, Carme Gimeno; Luna, Pedro Vera; Pastor, Jaime Prat

    2007-12-01

    This study aims to present a new concept of a knee hinge based on a crossed four-bar linkage mechanism which has been designed to optimally follow a motion curve representing the knee kinematics in the position at which the knee hinge should be placed. The methodology used to determine the optimal knee hinge is based on the optimization of certain variables of the crossed four-bar mechanism using genetic algorithms in order to follow a certain motion curve, which was determined using a biomechanical model of the knee motion. Two current, commercially available knee hinges have been used to theoretically determine their motion by means of the path performed by their instantaneous helical axis. Comparison between these two different knee hinges, Optimal Knee Hinge and the theoretical motion performed by a human knee reveals that a common monocentric hinge has a maximum misalignment of up to 27.2 mm; a polycentric hinge has a maximum misalignment of 23.9 mm. In contrast, the maximum misalignment produced by the Optimal Knee Hinge is 1.99 mm. The orthotic joint presented significantly improves the kinematical compatibility and the adjustment between orthotic and human joint motion, and should provide several advantages in terms of comfort and safety. Furthermore, the determination of the instantaneous helical axis for a particular user, by means of human movement measurement techniques, will enable the optimal crossed four-bar mechanisms to be determined in a customized and personalized manner. As a consequence, this new concept of orthotic knee joint design may improve the adaptability of lower limb orthoses for the user, and may lead to significant advantages in the field of orthotics for the lower limb. PMID:18050008

  9. Initial experience with active breathing control of liver motion during ventilation

    International Nuclear Information System (INIS)

    Purpose: Recent evidence has shown that some patients with hepatic tumors can be safely irradiated to a dose well over twice the whole liver tolerance dose if portions of normal liver are spared. Correction during treatment planning for the ventilatory motion of the liver can add a large volume of normal liver to the planning target volume. Any reduction in ventilatory motion has the potential to allow a higher dose of radiation to be given safely. Active Breathing Control (ABC) can be used to temporarily stop the airflow to a patient, thus immobilizing the liver, at any part of a patient's ventilatory cycle. ABC during helical CT scanning can be used to study the full three dimensional motion of the liver and other abdominal organs during ventilation. Ultimately, if the use of ABC is found to be clinically feasible, tolerable for patients, and, most importantly, reproducible over time, then ABC may be used during radiation treatment. Materials and Methods: An ABC apparatus was constructed using a flow monitor and scissor valves on both the inhalation and exhalation paths to the patient. The patient breathed through either a mouthpiece or facemask during the procedure. The ventilatory cycle was displayed in real time. When a stable breathing pattern was observed, the ABC was activated at a specific lung volume, closing both scissors valves, and preventing ventilation. The length of time for comfortable activation of the ABC machine for the individual patient was determined during a teaching and practice period prior to CT scanning. Helical CT scans (slice thickness 0.5 cm) to assess the potential benefit of immobilizing breathing were obtained for normal breathing, end-inspiration and end-expiration. The reproducibility of ABC over time was assessed by repeating the end-inspiration scan both immediately and one week later. The contours of the liver and kidneys were entered for each study. Results: Five patients have undergone ABC study of the abdomen. End

  10. Control of a Virtual Vehicle Influences Postural Activity and Motion Sickness

    Science.gov (United States)

    Dong, Xiao; Yoshida, Ken; Stoffregen, Thomas A.

    2011-01-01

    Everyday experience suggests that drivers are less susceptible to motion sickness than passengers. In the context of inertial motion (i.e., physical displacement), this effect has been confirmed in laboratory research using whole body motion devices. We asked whether a similar effect would occur in the context of simulated vehicles in a visual…

  11. Strategies for the prevention of knee osteoarthritis

    DEFF Research Database (Denmark)

    Roos, Ewa M; Arden, Nigel K

    2016-01-01

    , interfering with activities of daily living and the ability to work. Many patients tolerate pain, and many health-care providers accept pain and disability as inevitable corollaries of OA and ageing. Too often, health-care providers passively await final 'joint death', necessitating knee and hip replacements......-the regimes. Now is the time to begin the era of personalized prevention for knee OA....

  12. Mechanisms of improved knee flexion after rectus femoris transfer surgery

    OpenAIRE

    Fox, Melanie D.; Reinbolt, Jeffrey A.; Õunpuu, Sylvia; Delp, Scott L.

    2009-01-01

    Rectus femoris transfer is frequently performed to treat stiff-knee gait in subjects with cerebral palsy. In this surgery, the distal tendon is released from the patella and re-attached to one of several sites, such as the sartorius or the iliotibial band. Surgical outcomes vary, and the mechanisms by which the surgery improves knee motion are unclear. The purpose of this study was to clarify the mechanism by which the transferred muscle improves knee flexion by examining three types of trans...

  13. Traumatic chylous knee effusion.

    OpenAIRE

    Reginato, A J; Feldman, E; Rabinowitz, J L

    1985-01-01

    A 47-year-old patient presented with a chylous knee effusion and traumatic infected skin lacerations. The diagnosis of septic arthritis was considered because of purulent looking joint fluid, spuriously high synovial fluid white cell count, and signs of acute knee synovitis. Synovial fluid lipid analysis showed increased total lipids due to high concentration of neutral lipids, mainly triglycerides, and repeated knee radiographs showed a small fracture of the tibial spine. Joint trauma with s...

  14. Predicting dynamic knee joint load with clinical measures in people with medial knee osteoarthritis.

    Science.gov (United States)

    Hunt, Michael A; Bennell, Kim L

    2011-08-01

    Knee joint loading, as measured by the knee adduction moment (KAM), has been implicated in the pathogenesis of knee osteoarthritis (OA). Given that the KAM can only currently be accurately measured in the laboratory setting with sophisticated and expensive equipment, its utility in the clinical setting is limited. This study aimed to determine the ability of a combination of four clinical measures to predict KAM values. Three-dimensional motion analysis was used to calculate the peak KAM at a self-selected walking speed in 47 consecutive individuals with medial compartment knee OA and varus malalignment. Clinical predictors included: body mass; tibial angle measured using an inclinometer; walking speed; and visually observed trunk lean toward the affected limb during the stance phase of walking. Multiple linear regression was performed to predict KAM magnitudes using the four clinical measures. A regression model including body mass (41% explained variance), tibial angle (17% explained variance), and walking speed (9% explained variance) explained a total of 67% of variance in the peak KAM. Our study demonstrates that a set of measures easily obtained in the clinical setting (body mass, tibial alignment, and walking speed) can help predict the KAM in people with medial knee OA. Identifying those patients who are more likely to experience high medial knee loads could assist clinicians in deciding whether load-modifying interventions may be appropriate for patients, whilst repeated assessment of joint load could provide a mechanism to monitor disease progression or success of treatment.

  15. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting.

    Science.gov (United States)

    Proto, Antonino; Penhaker, Marek; Bibbo, Daniele; Vala, David; Conforto, Silvia; Schmid, Maurizio

    2016-01-01

    In this paper, two different piezoelectric transducers-a ceramic piezoelectric, lead zirconate titanate (PZT), and a polymeric piezoelectric, polyvinylidene fluoride (PVDF)-were compared in terms of energy that could be harvested during locomotion activities. The transducers were placed into a tight suit in proximity of the main body joints. Initial testing was performed by placing the transducers on the neck, shoulder, elbow, wrist, hip, knee and ankle; then, five locomotion activities-walking, walking up and down stairs, jogging and running-were chosen for the tests. The values of the power output measured during the five activities were in the range 6 µW-74 µW using both transducers for each joint. PMID:27077867

  16. Dopamine Activation Preserves Visual Motion Perception Despite Noise Interference of Human V5/MT

    Science.gov (United States)

    Yousif, Nada; Fu, Richard Z.; Abou-El-Ela Bourquin, Bilal; Bhrugubanda, Vamsee; Schultz, Simon R.

    2016-01-01

    When processing sensory signals, the brain must account for noise, both noise in the stimulus and that arising from within its own neuronal circuitry. Dopamine receptor activation is known to enhance both visual cortical signal-to-noise-ratio (SNR) and visual perceptual performance; however, it is unknown whether these two dopamine-mediated phenomena are linked. To assess this, we used single-pulse transcranial magnetic stimulation (TMS) applied to visual cortical area V5/MT to reduce the SNR focally and thus disrupt visual motion discrimination performance to visual targets located in the same retinotopic space. The hypothesis that dopamine receptor activation enhances perceptual performance by improving cortical SNR predicts that dopamine activation should antagonize TMS disruption of visual perception. We assessed this hypothesis via a double-blinded, placebo-controlled study with the dopamine receptor agonists cabergoline (a D2 agonist) and pergolide (a D1/D2 agonist) administered in separate sessions (separated by 2 weeks) in 12 healthy volunteers in a William's balance-order design. TMS degraded visual motion perception when the evoked phosphene and the visual stimulus overlapped in time and space in the placebo and cabergoline conditions, but not in the pergolide condition. This suggests that dopamine D1 or combined D1 and D2 receptor activation enhances cortical SNR to boost perceptual performance. That local visual cortical excitability was unchanged across drug conditions suggests the involvement of long-range intracortical interactions in this D1 effect. Because increased internal noise (and thus lower SNR) can impair visual perceptual learning, improving visual cortical SNR via D1/D2 agonist therapy may be useful in boosting rehabilitation programs involving visual perceptual training. SIGNIFICANCE STATEMENT In this study, we address the issue of whether dopamine activation improves visual perception despite increasing sensory noise in the visual cortex

  17. Aftershock activity of the 2015 Gorkha, Nepal, earthquake determined using the Kathmandu strong motion seismographic array

    Science.gov (United States)

    Ichiyanagi, Masayoshi; Takai, Nobuo; Shigefuji, Michiko; Bijukchhen, Subeg; Sasatani, Tsutomu; Rajaure, Sudhir; Dhital, Megh Raj; Takahashi, Hiroaki

    2016-02-01

    The characteristics of aftershock activity of the 2015 Gorkha, Nepal, earthquake (Mw 7.8) were evaluated. The mainshock and aftershocks were recorded continuously by the international Kathmandu strong motion seismographic array operated by Hokkaido University and Tribhuvan University. Full waveform data without saturation for all events enabled us to clarify aftershock locations and decay characteristics. The aftershock distribution was determined using the estimated local velocity structure. The hypocenter distribution in the Kathmandu metropolitan region was well determined and indicated earthquakes located shallower than 12 km depth, suggesting that aftershocks occurred at depths shallower than the Himalayan main thrust fault. Although numerical investigation suggested less resolution for the depth component, the regional aftershock epicentral distribution of the entire focal region clearly indicated earthquakes concentrated in the eastern margin of the major slip region of the mainshock. The calculated modified Omori law's p value of 1.35 suggests rapid aftershock decay and a possible high temperature structure in the aftershock region.

  18. Recommended survey designs for occupancy modelling using motion-activated cameras: insights from empirical wildlife data

    Directory of Open Access Journals (Sweden)

    Graeme Shannon

    2014-08-01

    Full Text Available Motion-activated cameras are a versatile tool that wildlife biologists can use for sampling wild animal populations to estimate species occurrence. Occupancy modelling provides a flexible framework for the analysis of these data; explicitly recognizing that given a species occupies an area the probability of detecting it is often less than one. Despite the number of studies using camera data in an occupancy framework, there is only limited guidance from the scientific literature about survey design trade-offs when using motion-activated cameras. A fuller understanding of these trade-offs will allow researchers to maximise available resources and determine whether the objectives of a monitoring program or research study are achievable. We use an empirical dataset collected from 40 cameras deployed across 160 km2 of the Western Slope of Colorado, USA to explore how survey effort (number of cameras deployed and the length of sampling period affects the accuracy and precision (i.e., error of the occupancy estimate for ten mammal and three virtual species. We do this using a simulation approach where species occupancy and detection parameters were informed by empirical data from motion-activated cameras. A total of 54 survey designs were considered by varying combinations of sites (10–120 cameras and occasions (20–120 survey days. Our findings demonstrate that increasing total sampling effort generally decreases error associated with the occupancy estimate, but changing the number of sites or sampling duration can have very different results, depending on whether a species is spatially common or rare (occupancy = ψ and easy or hard to detect when available (detection probability = p. For rare species with a low probability of detection (i.e., raccoon and spotted skunk the required survey effort includes maximizing the number of sites and the number of survey days, often to a level that may be logistically unrealistic for many studies. For common

  19. Driving technology for improving motion quality of active-matrix organic light-emitting diode display

    Science.gov (United States)

    Kim, Jongbin; Kim, Minkoo; Kim, Jong-Man; Kim, Seung-Ryeol; Lee, Seung-Woo

    2014-09-01

    This paper reports transient response characteristics of active-matrix organic light emitting diode (AMOLED) displays for mobile applications. This work reports that the rising responses look like saw-tooth waveform and are not always faster than those of liquid crystal displays. Thus, a driving technology is proposed to improve the rising transient responses of AMOLED based on the overdrive (OD) technology. We modified the OD technology by combining it with a dithering method because the conventional OD method cannot successfully enhance all the rising responses. Our method can improve all the transitions of AMOLED without modifying the conventional gamma architecture of drivers. A new artifact is found when OD is applied to certain transitions. We propose an optimum OD selection method to mitigate the artifact. The implementation results show the proposed technology can successfully improve motion quality of scrolling texts as well as moving pictures in AMOLED displays.

  20. A Circular Motion Activity with Hot Wheels® Rev-Ups

    Science.gov (United States)

    Wagner, Glenn

    2009-02-01

    Hot Wheels® Rev-Ups provide a pedagogically engaging and inexpensive culminating activity for the application of circular motion with constant speed in introductory mechanics. The introductory Rev-Up, shown in Fig. 1, consists of a very durable car with two strong magnets built into the front and back of the car. The track is a piece of flexible plastic with a built-in metallic strip through its center that can then be formed into a circle. Pushing the car forward several times on a flat surface allows the car to move in a vertical circle when placed inside the track. What makes this toy attractive is that the gearing system allows the car to move at a relatively constant speed for about three to five seconds before slowing down appreciably.

  1. Active Head Motion Compensation of TMS Robotic System Using Neuro-Fuzzy Estimation

    Directory of Open Access Journals (Sweden)

    Wan Zakaria W.N.

    2016-01-01

    Full Text Available Transcranial Magnetic Stimulation (TMS allows neuroscientist to study human brain behaviour and also become an important technique for changing the activity of brain neurons and the functions they sub serve. However, conventional manual procedure and robotized TMS are currently unable to precisely position the TMS coil because of unconstrained subject’s head movement and excessive contact force between the coil and subject’s head. This paper addressed this challenge by proposing an adaptive neuro-fuzzy force control to enable low contact force with a moving target surface. A learning and adaption mechanism is included in the control scheme to improve position disturbance estimation. The results show the ability of the proposed force control scheme to compensate subject’s head motions while maintaining desired contact force, thus allowing for more accurate and repeatable TMS procedures.

  2. Knee loading patterns in a simulated netball landing task.

    Science.gov (United States)

    Stuelcken, Max; Greene, Andrew; Smith, Richard; Vanwanseele, Benedicte

    2013-01-01

    The knee is a common site of injury in netball players. In this study, 10 high-performance netball players underwent a biomechanical assessment of their single leg landing technique whilst receiving a pass. Three-dimensional video and ground reaction force data were recorded using a motion analysis system. Net internal knee joint moments were calculated using a rigid body analysis and inverse dynamics. The kinematics of the support leg and front-on video footage was used to investigate whether players adhered to guidelines on safe and effective landing strategies. Results indicated that for most players the internal valgus moment was the largest frontal plane knee moment during the landing phase. This may reflect a relatively greater need to resist varus knee excursion or may be related to the kinematics of the hip. For 6 of the 10 players the rapid change to an internal knee valgus moment coincided with hip adduction. Since an increase in the magnitude of the internal valgus moment may increase the compressive forces in the medial compartment of the knee, further work should be undertaken to determine if a neuromuscular training intervention to improve the strength of the hip musculature may be beneficial for these players. A large relative excursion of the knee compared to the hip may indicate that these players had a greater reliance on the more distal segments of the lower extremity for the attenuation of the ground reaction forces. This information may be used to better understand potential knee injury mechanisms in netball players.

  3. Dynamic analysis of astronaut motions in microgravity: Applications for Extravehicular Activity (EVA)

    Science.gov (United States)

    Newman, Dava J.

    1995-01-01

    Simulations of astronaut motions during extravehicular activity (EVA) tasks were performed using computational multibody dynamics methods. The application of computational dynamic simulation to EVA was prompted by the realization that physical microgravity simulators have inherent limitations: viscosity in neutral buoyancy tanks; friction in air bearing floors; short duration for parabolic aircraft; and inertia and friction in suspension mechanisms. These limitations can mask critical dynamic effects that later cause problems during actual EVA's performed in space. Methods of formulating dynamic equations of motion for multibody systems are discussed with emphasis on Kane's method, which forms the basis of the simulations presented herein. Formulation of the equations of motion for a two degree of freedom arm is presented as an explicit example. The four basic steps in creating the computational simulations were: system description, in which the geometry, mass properties, and interconnection of system bodies are input to the computer; equation formulation based on the system description; inverse kinematics, in which the angles, velocities, and accelerations of joints are calculated for prescribed motion of the endpoint (hand) of the arm; and inverse dynamics, in which joint torques are calculated for a prescribed motion. A graphical animation and data plotting program, EVADS (EVA Dynamics Simulation), was developed and used to analyze the results of the simulations that were performed on a Silicon Graphics Indigo2 computer. EVA tasks involving manipulation of the Spartan 204 free flying astronomy payload, as performed during Space Shuttle mission STS-63 (February 1995), served as the subject for two dynamic simulations. An EVA crewmember was modeled as a seven segment system with an eighth segment representing the massive payload attached to the hand. For both simulations, the initial configuration of the lower body (trunk, upper leg, and lower leg) was a neutral

  4. A new method to measure post-traumatic joint contractures in the rabbit knee.

    Science.gov (United States)

    Hildebrand, Kevin A; Holmberg, Michael; Shrive, Nigel

    2003-12-01

    A new device and method to measure rabbit knee joint angles are described. The method was used to measure rabbit knee joint angles in normal specimens and in knee joints with obvious contractures. The custom-designed and manufactured gripping device has two clamps. The femoral clamp sits on a pinion gear that is driven by a rack attached to a materials testing system. A 100 N load cell in series with the rack gives force feedback. The tibial clamp is attached to a rotatory potentiometer. The system allows the knee joint multiple degrees-of-freedom (DOF). There are two independent DOF (compression-distraction and internal-external rotation) and two coupled motions (medial-lateral translation coupled with varus-valgus rotation; anterior-posterior translation coupled with flexion-extension rotation). Knee joint extension-flexion motion is measured, which is a combination of the materials testing system displacement (converted to degrees of motion) and the potentiometer values (calibrated to degrees). Internal frictional forces were determined to be at maximum 2% of measured loading. Two separate experiments were performed to evaluate rabbit knees. First, normal right and left pairs of knees from four New Zealand White (NZW) rabbits were subjected to cyclic loading. An extension torque of 0.2 Nm was applied to each knee. The average change in knee joint extension from the first to the fifth cycle was 1.9 deg +/- 1.5 deg (mean +/- sd) with a total of 49 tests of these eight knees. The maximum extension of the four left knees (tested 23 times) was 14.6 deg +/- 7.1 deg, and of the four right knees (tested 26 times) was 12.0 deg +/- 10.9 deg. There was no significant difference in the maximum extension between normal left and right knees. In the second experiment, nine skeletally mature NZW rabbits had stable fractures of the femoral condyles of the right knee that were immobilized for five, six or 10 weeks. The left knee served as an unoperated control. Loss of knee joint

  5. Muscle activity and hand motion in veterinarians performing laparoscopic training tasks with a box trainer.

    Science.gov (United States)

    Tapia-Araya, Angelo E; Usón-Gargallo, Jesús; Sánchez-Margallo, Juan A; Pérez-Duarte, Francisco J; Martin-Portugués, Idoia Díaz-Güemes; Sánchez-Margallo, Francisco M

    2016-02-01

    OBJECTIVE To evaluate muscle activity and hand motion in veterinarians performing a standard set of laparoscopic training tasks. SAMPLE 12 veterinarians with experience performing laparoscopic procedures. PROCEDURES Participants were asked to perform peg transfer, coordination, precision cutting, and suturing tasks in a laparoscopic box trainer. Activity of the right biceps brachii, triceps brachii, forearm flexor, forearm extensor, and trapezius muscles was analyzed by means of surface electromyography. Right hand movements and wrist angle data were registered through the use of a data glove, and risk levels for the wrist joint were determined by use of a modified rapid upper limb assessment (RULA) method. One-way repeated-measures ANOVA with a Bonferroni post hoc test was performed to compare values between tasks. RESULTS Activity in the biceps muscle did not differ significantly among the 4 tasks. Activity in the triceps, forearm flexor, and forearm extensor muscles was significantly higher during precision cutting than during the coordination task. Activity in the trapezius muscle was highest during the suturing task and did not differ significantly among the other 3 tasks. The RULA score was unacceptable (score, 3) for the coordination, peg transfer, and precision cutting tasks but was acceptable (score, 2) for the suturing task. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated that the ergonomics of laparoscopic training depended on the tasks performed and the design of the instruments used. Precision cutting and suturing tasks were associated with the highest muscle activity. Acceptable wrist position, as determined with the RULA method, was found with the suturing task, which was performed with an axial-handled instrument. (Am J Vet Res 2016;77:186-193). PMID:27027713

  6. Medial collateral ligament injuries of the knee: current treatment concepts

    OpenAIRE

    Chen, Lan; Kim, Paul D.; Ahmad, Christopher S.; Levine, William N.

    2007-01-01

    The medial collateral ligament is one of the most commonly injured ligaments of the knee. Most injuries result from a valgus force on the knee. The increased participation in football, ice hockey, and skiing has all contributed to the increased frequency of MCL injuries. Prophylactic knee bracing in contact sports may prevent injury; however, performance may suffer. The majority of patients who sustain an MCL injury will achieve their pre-injury activity level with non-operative treatment alo...

  7. Total knee arthroplasty using computer assisted navigation in patients with severe valgus deformity of the knee

    Institute of Scientific and Technical Information of China (English)

    SHAO Jun-jie; ZHANG Xian-long; WANG Qi; CHEN Yun-su; SHEN Hao; JIANG Yao

    2010-01-01

    Background Severe valgus deformity often has bone defect and laxity of the medial ligamentous, and total knee arthroplasty in severe valgus knee is, in most cases, more challenging for surgeons. The usefulness of a computer assisted navigation system in reestablishing the mechanical axis has been well established. Hence, the interest for surgeons is how the navigation system makes the procedure of total knee arthroplasty with severe valgus knee easier.Methods From June 2006 to March 2008 in Department of Joint Surgery, Shanghai Sixth People's Hospital, 6 patients (7 knees) with severe valgus knee underwent total knee arthroplasty using the Stryker Navigation system, which is an active wireless and imageless system. All the patients were followed up for 12 to 18 months after surgery. The X-ray radiographs for whole limbs were obtained on all patients to determine preoperative and postoperative alignments.Results A primary, posterior stabilized prosthesis was utilized in all cases. The average preoperative overall mechanical axis of the seven knees was 19.6°±4.6° of valgus (range 16° to 29°), and the average postoperative mechanical axis was 0.4°±0.7° (range 0.8° varus to 1.4° valgus ).Conclusions The navigation system is a very effective and useful tool for accurate intraoperative restoration of alignment in the face of significant deformity with valgus knee. To prevent component malposition, we did not reduce the knee before solidification of bone cement but controlled alignment using the navigation system up to implantation of the final component.

  8. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting

    Directory of Open Access Journals (Sweden)

    Antonino Proto

    2016-04-01

    Full Text Available In this paper, two different piezoelectric transducers—a ceramic piezoelectric, lead zirconate titanate (PZT, and a polymeric piezoelectric, polyvinylidene fluoride (PVDF—were compared in terms of energy that could be harvested during locomotion activities. The transducers were placed into a tight suit in proximity of the main body joints. Initial testing was performed by placing the transducers on the neck, shoulder, elbow, wrist, hip, knee and ankle; then, five locomotion activities—walking, walking up and down stairs, jogging and running—were chosen for the tests. The values of the power output measured during the five activities were in the range 6 µW–74 µW using both transducers for each joint.

  9. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting

    Science.gov (United States)

    Proto, Antonino; Penhaker, Marek; Bibbo, Daniele; Vala, David; Conforto, Silvia; Schmid, Maurizio

    2016-01-01

    In this paper, two different piezoelectric transducers—a ceramic piezoelectric, lead zirconate titanate (PZT), and a polymeric piezoelectric, polyvinylidene fluoride (PVDF)—were compared in terms of energy that could be harvested during locomotion activities. The transducers were placed into a tight suit in proximity of the main body joints. Initial testing was performed by placing the transducers on the neck, shoulder, elbow, wrist, hip, knee and ankle; then, five locomotion activities—walking, walking up and down stairs, jogging and running—were chosen for the tests. The values of the power output measured during the five activities were in the range 6 µW–74 µW using both transducers for each joint. PMID:27077867

  10. Is Lifelong Knee Joint Force from Work, Home, and Sport Related to Knee Osteoarthritis?

    OpenAIRE

    Ratzlaff, Charles R.; Mieke Koehoorn; Jolanda Cibere; Jacek A. Kopec

    2012-01-01

    Purpose. To investigate the association of cumulative lifetime knee joint force on the risk of self-reported medically-diagnosed knee osteoarthritis (OA). Methods. Exposure data on lifetime physical activity type (occupational, household, sport/recreation) and dose (frequency, intensity, duration) were collected from 4,269 Canadian men and women as part of the Physical Activity and Joint Heath cohort study. Subjects were ranked in terms of the “cumulative peak force index”, a measure of lifet...

  11. A parallelogram-based compliant remote-center-of-motion stage for active parallel alignment

    Science.gov (United States)

    Qu, Jianliang; Chen, Weihai; Zhang, Jianbin

    2014-09-01

    Parallel alignment stage with remote-center-of-motion (RCM) is of key importance in precision out-of-plane aligning since it can eliminate the harmful lateral displacement generated at the output platform. This paper presents the development of a parallelogram-based compliant RCM stage for active parallel alignment. Different from conventional parallelogram-based RCM mechanism, the proposed stage is designed with compliant mechanisms, which endows the stage with many attractive merits when used in precision micro-/nanomanipulations. A symmetric double-parallelogram mechanism (SDPM) based on flexure hinges is developed as the rotary guiding component to realize desired RCM function. Due to the geometrical constraint of the SDPM, the operating space of the stage can be easily adjusted by bending the input links without loss of rotational precision. The stage is driven by a piezoelectric actuator and its output motion is measured by non-contact displacement sensors. Based on pseudo-rigid-body simplification method, the analytical models predicting kinematics, statics, and dynamics of the RCM stage have been established. Besides, the dimensional optimization is conducted in order to maximize the first resonance frequency of the stage. After that, finite element analysis is conducted to validate the established models and the prototype of the stage is fabricated for performance tests. The experimental results show that the developed RCM stage has a rotational range of 1.45 mrad while the maximum center shift of the RCM point is as low as 1 μm, which validate the effectiveness of the proposed scheme.

  12. Revision Knee Surgery

    Medline Plus

    Full Text Available Revision Knee Surgery Featuring the Zimmer® NexGen® LCCK System. Zimmer, Inc. Indio, California March 31, 2010 Welcome to this ... surgery, demonstrating the role of the NexGen LCCK Knee Revision System. If we could go to the ...

  13. Preventing Knee Injuries

    Science.gov (United States)

    ... to tearing. Growth Plate Injuries, Fractures, and Dislocations Knee fractures rarely occur in childhood sports, but with any ... is the bump on the front of the knee where the patellar tendon attaches. Fractures to the growth plate in this area often ...

  14. Revision Knee Surgery

    Medline Plus

    Full Text Available Revision Knee Surgery Featuring the Zimmer® NexGen® LCCK System. Zimmer, Inc. Indio, California March 31, 2010 Welcome ... the role of the NexGen LCCK Knee Revision System. If we could go to the slides, please. ...

  15. Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients

    Energy Technology Data Exchange (ETDEWEB)

    Hemke, Robert; Lavini, Cristina; Maas, Mario [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); Nusman, Charlotte M. [University of Amsterdam, Department of Radiology, Academic Medical Center, Amsterdam (Netherlands); University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Berg, J.M. van den; Schonenberg-Meinema, Dieneke; Kuijpers, Taco W. [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Dolman, Koert M. [Department of Pediatric Rheumatology, Reade, Amsterdam (Netherlands); St. Lucas Andreas Hospital, Department of Pediatrics, Amsterdam (Netherlands); Rossum, Marion A.J. van [University of Amsterdam, Department of Pediatric Hematology, Immunology, Rheumatology and Infectious Disease, Emma Children' s Hospital AMC, Amsterdam (Netherlands); Department of Pediatric Rheumatology, Reade, Amsterdam (Netherlands)

    2014-07-15

    To compare DCE-MRI parameters and the relative number of time-intensity curve (TIC) shapes as derived from pixel-by-pixel DCE-MRI TIC shape analysis between knees of clinically active and inactive juvenile idiopathic arthritis (JIA) patients. DCE-MRI data sets were prospectively obtained. Patients were classified into two clinical groups: active disease (n = 43) and inactive disease (n = 34). Parametric maps, showing seven different TIC shape types, were created per slice. Statistical measures of different TIC shapes, maximal enhancement (ME), maximal initial slope (MIS), initial area under the curve (iAUC), time-to-peak (TTP), enhancing volume (EV), volume transfer constant (K {sup trans}), extravascular space fractional volume (V{sub e}) and reverse volume transfer constant (k{sub ep}) of each voxel were calculated in a three-dimensional volume-of-interest of the synovial membrane. Imaging findings from 77 JIA patients were analysed. Significantly higher numbers of TIC shape 4 (P = 0.008), median ME (P = 0.015), MIS (P = 0.001) and iAUC (P = 0.002) were observed in clinically active compared with inactive patients. TIC shape 5 showed higher presence in the clinically inactive patients (P = 0.036). The pixel-by-pixel DCE-MRI TIC shape analysis method proved capable of differentiating clinically active from inactive JIA patients by the difference in the number of TIC shapes, as well as the descriptive parameters ME, MIS and iAUC. (orig.)

  16. Musculoskeletal MR: knee

    Energy Technology Data Exchange (ETDEWEB)

    Staebler, A.; Glaser, C.; Reiser, M. [Dept. of Diagnostic Radiology, Klinikum Grosshadern, Ludwig-Maximilian Universitaet Muenchen (Germany)

    2000-02-01

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  17. Musculoskeletal MR: knee

    International Nuclear Information System (INIS)

    Magnetic resonance imaging is the most sensitive, specific, and accurate noninvasive method for diagnosing internal derangement of the knee. During the past 15 years knowledge of pathologic conditions of the knee had evolved significantly. Beyond the basic principles of imaging knee injuries great impact was made on the understanding of indirect or collateral findings, even in rare diseases. In this article the spectrum of disorders of the knee are reviewed and an overview of the current literature is given. This includes considerations about how to achieve a high-standard MR imaging study of the knee, and principles of imaging anterior cruciate ligament and meniscal tears. A focus is put on distinct diseases including intra-articular and intraosseous ganglion cysts, iliotibial band friction syndrome, transient osteoporosis, osteonecrosis, osteochondritis dissecans, and imaging of the articular cartilage. (orig.)

  18. Bicompartmental knee arthroplasty.

    Science.gov (United States)

    Sabatini, Luigi; Giachino, Matteo; Risitano, Salvatore; Atzori, Francesco

    2016-01-01

    Total knee arthroplasty (TKA) is the most worldwide practiced surgery for knee osteoarthritis and its efficacy is mightily described by literature. Concerns about the invasiveness of TKA let the introduction of segmental resurfacing of the joint for younger patients with localized osteoarthritis. Bone stock sparing and ligaments preservation are the essence of both unicompartmental knee arthroplasty (UKA) and bicompartmental knee arthroplasty (BKA). Advantages related to BKA are the respect of knee biomechanics, lower complications rates, shorter hospital stay, faster rehabilitation. Moreover, in case of failure of the first implant the conversion to TKA is undemanding and can be compared to a standard prosthesis. Our experience suggest that BKA is a reliable technique in selected cases and especially younger people with higher functional requests can favourably profit from it. Although those results are encouraging, we still need further prospective, randomized, long-term studies to finally assess BKA indications and outcomes. PMID:26855941

  19. The Mechanistic Connection Between the Trunk, Knee, and Anterior Cruciate Ligament Injury

    OpenAIRE

    Hewett, Timothy E.; Myer, Gregory D.

    2011-01-01

    Neuromuscular control of the trunk and knee predicts anterior cruciate ligament injury risk with high sensitivity and specificity. These predictors are linked, as lateral trunk positioning creates high knee abduction torque (load). The hypotheses explored are that lateral trunk motion increases load and that neuromuscular training that increases trunk control will decrease load.

  20. Gait patterns after intraarticular treatment of patients with osteoarthritis of the Knee - Hyaluronan versus triamcinolone: a prospective, randomized, doubleblind, monocentric study

    Directory of Open Access Journals (Sweden)

    Skwara A

    2009-04-01

    Full Text Available Abstract Objective Evaluation of gait performance and muscle activity patterns as well as clinical efficacy and safety after single intraarticular injection with hyaluronan compared with triamcinolone in patients with knee osteoarthritis. Materials and Methods This trial evaluated the influence of a single injection of hyaluronan or triamcinolone on gait pattern and muscle activity. For clinical evaluation a visual analogue scale for pain, Lequesne index, and Knee Society Score were used. Quality of life was assessed with the SF-36. Results The complete analysis was performed in 50 of 60 patients. 26 patients were treated with triamcinolone and 24 with hyaluronan. Hyaluronan treatment led to significant improvement of range of motion at hip and knee. Significant improvement could be either demonstrated for the pain scale, Lequesne and Knee Society score in both groups. Quality of life showed greater improvement in the triamcinolone group. Conclusion Single application of high-viscosity hyaluronan shows superior range of motion and pain reduction as well as improvement in clinical results. Even if there was a lack of significant differences compared to triamcinolone, this therapy classified as safe and effective in the short follow up.

  1. Detection of active sacroiliitis with ankylosing spondylitis through intravoxel incoherent motion diffusion-weighted MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Ying-hua [Third Affiliated Hospital of Southern Medical University, Academy of Orthopedics, Department of Radiology, Guangzhou (China); Guangdong Academy of Medical Sciences, Department of Radiology, Guangdong General Hospital, Guangzhou (China); Li, Shao-lin; Zhao, Xiang-cheng; Hu, Shao-yong; Liu, Zhen-hua [Third Affiliated Hospital of Southern Medical University, Academy of Orthopedics, Department of Radiology, Guangzhou (China); Liu, Zai-yi; Chen, Xin; Liang, Chang-hong [Guangdong Academy of Medical Sciences, Department of Radiology, Guangdong General Hospital, Guangzhou (China); Mei Ms, Ying-jie [Philips Healthcare, Guangzhou (China); Chan, Queenie [Philips Electronics Hong Kong Ltd, Hong Kong (China)

    2015-09-15

    To confirm feasibility and assess intravoxel incoherent motion (IVIM) to differentiate active sacroiliitis and ankylosing spondylitis. Forty-one patients were divided into two groups, an active group (n = 20) and a chronic group (n = 21), according to the Bath Ankylosing Spondylitis (AS) Disease Activity Index (BASDAI) and laboratory parameters. In addition, 21 healthy volunteers were chosen as the control group. Tissue diffusivity (D{sub slow}), perfusion fraction (f), and pseudo-diffusion coefficient (D{sub fast}) values were obtained for all three groups. One-way analysis of variance and receiver operating characteristic analysis were performed for all parameters. There was good interobserver agreement on the measurements between the two observers. The optimal cut-off values (with respective AUC, sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio) between active and chronic groups were D{sub slow} = 0.53 x 10{sup -3} mm{sup 2}/s (0.976, 90 %, 95.2 %, 18.9, 0.10) and f = 0.09 (0.545, 20 %, 95.5 %, 4.2, 0.84), and between chronic and control groups were D{sub slow} = 0.22 x 10{sup -3} mm{sup 2}/s (0.517, 9.52 %, 100 %, no number, 0.9) and f = 0.09 (0.935, 95.24 %, 80.95 %, 5, 0.059). D{sub slow} and f of IVIM diffusion-weighted (DW)-MRI in AS show a significant difference in the values of diffusion of water molecules and fractional perfusion-related volume among the three groups. (orig.)

  2. Total Knee Replacement for Women

    Medline Plus

    Full Text Available ... this knee differ from the high-flex mobile bearing knee?” Well this is not a mobile bearing knee. There is a lot of controversy as to whether or not a mobile-bearing knee provides any significant benefit to the patient. ...

  3. Muscle co-contraction during gait in individuals with articular cartilage defects in the knee.

    Science.gov (United States)

    Thoma, Louise M; McNally, Michael P; Chaudhari, Ajit M; Flanigan, David C; Best, Thomas M; Siston, Robert A; Schmitt, Laura C

    2016-07-01

    Increased muscle co-contraction during gait is common in individuals with knee pathology, and worrisome as it is known to amplify tibiofemoral compressive forces. While knees with articular cartilage defects (ACD) are more vulnerable to compressive forces, muscle co-contraction has never been reported in this population. The purpose of this study was to evaluate the extent to which individuals with ACDs in the knee demonstrate elevated quadriceps to hamstrings muscle co-contraction on the involved limb during gait compared to the uninvolved limb and to healthy controls. We also explored the impact of participant characteristics and knee impairments on co-contraction. Twenty-nine individuals with full-thickness knee ACDs (ACD group) and 19 healthy adults (control group) participated in this study. Participants performed five gait trials at self-selected speed, during which activity of the quadriceps and hamstrings muscles were collected with surface electromyography. Three-dimensional motion capture was used to define phases of gait. Quadriceps strength and self-reported outcomes were also assessed in the same session. There were no differences in quadriceps: hamstrings co-contraction between the ACD and control groups, or between the involved and uninvolved limb for the ACD group. For both ACD and control groups, co-contraction was highest in early stance and lowest in late stance. Quadriceps strength was consistently the strongest predictor of muscle co-contraction in both the ACD and the control groups, with individuals with lower strength demonstrating greater co-contraction. Further study is needed to understand the effect of increased muscle co-contraction on joint compressive forces in the presence of varied quadriceps strength.

  4. Soft tissue twisting injuries of the knee

    International Nuclear Information System (INIS)

    Twisting injuries occur as a result of differential motion of different tissue types in injuries with some rotational force. These injuries are well described in brain injuries but, to our knowledge, have not been described in the musculoskeletal literature. We correlated the clinical examination and MR findings of 20 patients with twisting injuries of the soft tissues around the knee. Design and patients: We prospectively followed the clinical courses of 20 patients with knee injuries who had clinical histories and MR findings to suggest twisting injuries of the subcutaneous tissues. Patients with associated internal derangement of the knee (i.e., meniscal tears, ligamentous or bone injuries) were excluded from this study. MR findings to suggest twisting injuries included linear areas of abnormal dark signal on T1-weighted sequences and abnormal bright signal on T2-weighted or short tau inversion recovery (STIR) sequences and/or signal to suggest hemorrhage within the subcutaneous tissues. These MR criteria were adapted from those established for indirect musculotendinous junction injuries. Results: All 20 patients presented with considerable pain that suggested internal derangement on physical examination by the referring orthopedic surgeons. All presented with injuries associated with rotational force. The patients were placed on a course of protected weight-bearing of the affected extremity for 4 weeks. All patients had pain relief by clinical examination after this period of protected weight-bearing. Twisting injuries of the soft tissues can result in considerable pain that can be confused with internal derangement of the knee on physical examination. Soft tissue twisting injuries need to be recognized on MR examinations as they may be the cause of the patient's pain despite no MR evidence of internal derangement of the knee. The demonstration of soft tissue twisting injuries in a patient with severe knee pain but no documented internal derangement on MR

  5. Soft tissue twisting injuries of the knee

    Energy Technology Data Exchange (ETDEWEB)

    Magee, T.; Shapiro, M. [Neuroimaging Inst., Melbourne, FL (United States)

    2001-08-01

    Twisting injuries occur as a result of differential motion of different tissue types in injuries with some rotational force. These injuries are well described in brain injuries but, to our knowledge, have not been described in the musculoskeletal literature. We correlated the clinical examination and MR findings of 20 patients with twisting injuries of the soft tissues around the knee. Design and patients: We prospectively followed the clinical courses of 20 patients with knee injuries who had clinical histories and MR findings to suggest twisting injuries of the subcutaneous tissues. Patients with associated internal derangement of the knee (i.e., meniscal tears, ligamentous or bone injuries) were excluded from this study. MR findings to suggest twisting injuries included linear areas of abnormal dark signal on T1-weighted sequences and abnormal bright signal on T2-weighted or short tau inversion recovery (STIR) sequences and/or signal to suggest hemorrhage within the subcutaneous tissues. These MR criteria were adapted from those established for indirect musculotendinous junction injuries. Results: All 20 patients presented with considerable pain that suggested internal derangement on physical examination by the referring orthopedic surgeons. All presented with injuries associated with rotational force. The patients were placed on a course of protected weight-bearing of the affected extremity for 4 weeks. All patients had pain relief by clinical examination after this period of protected weight-bearing. Twisting injuries of the soft tissues can result in considerable pain that can be confused with internal derangement of the knee on physical examination. Soft tissue twisting injuries need to be recognized on MR examinations as they may be the cause of the patient's pain despite no MR evidence of internal derangement of the knee. The demonstration of soft tissue twisting injuries in a patient with severe knee pain but no documented internal derangement on MR

  6. 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.

  7. Wearable Sensor-Based Rehabilitation Exercise Assessment for Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Kun-Hui Chen

    2015-02-01

    Full Text Available Since the knee joint bears the full weight load of the human body and the highest pressure loads while providing flexible movement, it is the body part most vulnerable and susceptible to osteoarthritis. In exercise therapy, the early rehabilitation stages last for approximately six weeks, during which the patient works with the physical therapist several times each week. The patient is afterwards given instructions for continuing rehabilitation exercise by him/herself at home. This study develops a rehabilitation exercise assessment mechanism using three wearable sensors mounted on the chest, thigh and shank of the working leg in order to enable the patients with knee osteoarthritis to manage their own rehabilitation progress. In this work, time-domain, frequency-domain features and angle information of the motion sensor signals are used to classify the exercise type and identify whether their postures are proper or not. Three types of rehabilitation exercise commonly prescribed to knee osteoarthritis patients are: Short-Arc Exercise, Straight Leg Raise, and Quadriceps Strengthening Mini-squats. After ten subjects performed the three kinds of rehabilitation activities, three validation techniques including 10-fold cross-validation, within subject cross validation, and leave-one-subject cross validation are utilized to confirm the proposed mechanism. The overall recognition accuracy for exercise type classification is 97.29% and for exercise posture identification it is 88.26%. The experimental results demonstrate the feasibility of the proposed mechanism which can help patients perform rehabilitation movements and progress effectively. Moreover, the proposed mechanism is able to detect multiple errors at once, fulfilling the requirements for rehabilitation assessment.

  8. A randomized clinical trial of a peri-operative behavioral intervention to improve physical activity adherence and functional outcomes following total knee replacement

    Directory of Open Access Journals (Sweden)

    Zheng Hua

    2011-10-01

    Full Text Available Abstract Background Total knee replacement (TKR is a common and effective surgical procedure to relieve advanced knee arthritis that persists despite comprehensive medical treatment. Although TKR has excellent technical outcomes, significant variation in patient-reported functional improvement post-TKR exists. Evidence suggests that consistent post-TKR exercise and physical activity is associated with functional gain, and that this relationship is influenced by emotional health. The increasing use of TKR in the aging US population makes it critical to find strategies that maximize functional outcomes. Methods/Design This randomized clinical trial (RCT will test the efficacy of a theory-based telephone-delivered Patient Self-Management Support intervention that seeks to enhance adherence to independent exercise and activity among post- TKR patients. The intervention consists of 12 sessions, which begin prior to surgery and continue for approximately 9 weeks post-TKR. The intervention condition will be compared to a usual care control condition using a randomized design and a probabilistic sample of men and women. Assessments are conducted at baseline, eight weeks, and six- and twelve- months. The project is being conducted at a large healthcare system in Massachusetts. The study was designed to provide greater than 80% power for detecting a difference of 4 points in physical function (SF36/Physical Component Score between conditions (standard deviation of 10 at six months with secondary outcomes collected at one year, assuming a loss to follow up rate of no more than 15%. Discussion As TKR use expands, it is important to develop methods to identify patients at risk for sub-optimal functional outcome and to effectively intervene with the goal of optimizing functional outcomes. If shown efficacious, this peri-TKR intervention has the potential to change the paradigm for successful post-TKR care. We hypothesize that Patient Self-Management Support

  9. Outcomes of Varus Valgus Constrained Versus Rotating-Hinge Implants in Total Knee Arthroplasty.

    Science.gov (United States)

    Malcolm, Tennison L; Bederman, S Samuel; Schwarzkopf, Ran

    2016-01-01

    The stability of a total knee arthroplasty is determined by the ability of the prosthesis components in concert with supportive bone and soft tissue structures to sufficiently resist deforming forces transmitted across the knee joint. Constrained prostheses are used in unstable knees due to their ability to resist varus and valgus transformative forces across the knee. Constraint requires inherent rigidity, which can facilitate early implant failure. The purpose of this study was to describe the comparative indications for surgery and postoperative outcomes of varus valgus constrained knee (VVK) and rotating-hinge knee (RHK) total knee arthroplasty prostheses. Seven retrospective observational studies describing 544 VVK and 254 RHK patients with an average follow-up of 66 months (range, 7-197 months) were evaluated. Patients in both groups experienced similar failure rates (P=.74), ranges of motion (P=.81), and Knee Society function scores (P=.29). Average Knee Society knee scores were 4.2 points higher in VVK patients compared with RHK patients, indicating minimal mid-term clinical differences may exist (P<.0001). Absent collateral ligament support is an almost universal indication for RHK implantation vs VVK. Constrained device implantation is routinely guided by inherent stability of the knee, and, when performed, similar postoperative outcomes can be achieved with VVK and RHK prostheses.

  10. Fatigue effects on knee joint stability during two jump tasks in women.

    Science.gov (United States)

    Ortiz, Alexis; Olson, Sharon L; Etnyre, Bruce; Trudelle-Jackson, Elaine E; Bartlett, William; Venegas-Rios, Heidi L

    2010-04-01

    Dynamic knee joint stability may be affected by the onset of metabolic fatigue during sports participation that could increase the risk for knee injury. The purpose of this investigation was to determine the effects of metabolic fatigue on knee muscle activation, peak knee joint angles, and peak knee internal moments in young women during 2 jumping tasks. Fifteen women (mean age: 24.6 +/- 2.6 years) participated in one nonfatigued session and one fatigued session. During both sessions, peak knee landing flexion and valgus joint angles, peak knee extension and varus/valgus internal moments, electromyographic (EMG) muscle activity of the quadriceps and hamstrings, and quadriceps/hamstring EMG cocontraction ratio were measured. The tasks consisted of a single-legged drop jump from a 40-cm box and a 20-cm, up-down, repeated hop task. The fatigued session included a Wingate anaerobic protocol followed by performance of the 2 tasks. Although participants exhibited greater knee injury-predisposing factors during the fatigued session, such as lesser knee flexion joint angles, greater knee valgus joint angles, and greater varus/valgus internal joint moments for both tasks, only knee flexion during the up-down task was statistically significant (p = 0.028). Metabolic fatigue may perhaps predispose young women to knee injuries by impairing dynamic knee joint stability. Training strength-endurance components and the ability to maintain control of body movements in either rested or fatigued situations might help reduce injuries in young women athletes. PMID:20300024

  11. Acute Effects of Foot Rotation in Healthy Adults during Running on Knee Moments and Lateral-Medial Shear Force.

    Science.gov (United States)

    Valenzuela, Kevin A; Lynn, Scott K; Noffal, Guillermo J; Brown, Lee E

    2016-03-01

    As runners age, the likelihood of developing osteoarthritis (OA) significantly increases as 10% of people 55+ have symptomatic knee OA while 70% of people 65+ have radiographic signs of knee OA. The lateral-medial shear force (LMF) and knee adduction moment (KAM) during gait have been associated with cartilage loading which can lead to OA. Foot rotation during gait has been shown to alter the LMF and KAM, however it has not been investigated in running. The purpose of this study was to investigate changes in the KAM and LMF with foot rotation during running. Twenty participants volunteered and performed five running trials in three randomized conditions (normal foot position [NORM], external rotation [EXT], and internal rotation [INT]) at a running speed of 3.35m·s(-1) on a 20 meter runway. Kinematic and kinetic data were gathered using a 9-camera motion capture system and a force plate, respectively. Repeated measures ANOVAs determined differences between conditions. The KAM and LMF were lower in both EXT and INT conditions compared to the NORM, but there were no differences between EXT and INT conditions. The decreases in KAM and LMF in the EXT condition were expected and concur with past research in other activities. The reductions in the INT condition were unexpected and contradict the literature. This may indicate that participants are making mechanical compensations at other joints to reduce the KAM and LMF in this abnormal internal foot rotation condition. Key pointsExternal rotation of the foot during running reduced the loads on the medial compartment of the kneeInternal rotation of the foot also reduced the medial loads, but is a more unnatural interventionExternal and internal rotation reduced the shear forces on the knee, which may help slow the degeneration of knee joint cartilage. PMID:26957926

  12. Highly conforming polyethylene inlays reduce the in vivo variability of knee joint kinematics after total knee arthroplasty.

    Science.gov (United States)

    Daniilidis, Kiriakos; Skwara, Adrian; Vieth, Volker; Fuchs-Winkelmann, Susanne; Heindel, Walter; Stückmann, Volker; Tibesku, Carsten O

    2012-08-01

    The use of highly conforming polyethylene inlays in total knee arthroplasty (TKA) provides improved anteroposterior stability. The aim of this fluoroscopic study was to investigate the in vivo kinematics during unloaded and loaded active extension with a highly conforming inlay and a flat inlay after cruciate retaining (CR) total knee arthroplasty (TKA). Thirty one patients (50 knees) received a fixed-bearing cruciate retaining total knee arthroplasty (Genesis II, Smith & Nephew, Schenefeld, Germany) for primary knee osteoarthritis. Twenty two of them received a flat polyethylene inlay (PE), nine a deep dished PE and 19 were in the control group (physiological knees). The mean age at the time of surgery was 62 years. Dynamic examination with fluoroscopy was performed to assess the "patella tendon angle" in relation to the knee flexion angle (measure of anteroposterior translation) and the "kinematic index" (measure of reproducibility). Fluoroscopy was performed under active extension and flexion, during unloaded movement, and under full weight bearing, simulated by step climbing. No significant difference was observed between both types of polyethylene inlay designs and the physiological knee during unloaded movement. Anteroposterior (AP) instability was found during weight-bearing movement. The deep-dish inlay resulted in lower AP translation and a non-physiological rollback. Neither inlay types could restore physiological kinematics of the knee. Despite the fact that deep dished inlays reduce the AP translation, centralisation of contact pressure results in non-physiological rollback. The influence of kinematic pattern variability on clinical results warrants further investigation.

  13. A Passive Dynamic Walking Model Based on Knee-Bend Behaviour: Stability and Adaptability for Walking Down Steep Slopes

    Directory of Open Access Journals (Sweden)

    Kang An

    2013-10-01

    Full Text Available This paper presents a passive dynamic walking model based on knee-bend behaviour, which is inspired by the way human beings walk. The length and mass parameters of human beings are used in the walking model. The knee-bend mechanism of the stance leg is designed in the phase between knee-strike and heel- strike. q* which is the angular difference of the stance leg between the two events, knee-strike and knee-bend, is adjusted in order to find a stable walking motion. The results show that the stable periodic walking motion on a slope of r <0.4 can be found by adjusting q*. Furthermore, with a particular q* in the range of 0.12motion is more stable and adaptable than the conventional walking motion, especially for steep slopes.

  14. A framework for activity detection in wide-area motion imagery

    Energy Technology Data Exchange (ETDEWEB)

    Porter, Reid B [Los Alamos National Laboratory; Ruggiero, Christy E [Los Alamos National Laboratory; Morrison, Jack D [Los Alamos National Laboratory

    2009-01-01

    Wide-area persistent imaging systems are becoming increasingly cost effective and now large areas of the earth can be imaged at relatively high frame rates (1-2 fps). The efficient exploitation of the large geo-spatial-temporal datasets produced by these systems poses significant technical challenges for image and video analysis and data mining. In recent years there has been significant progress made on stabilization, moving object detection and tracking and automated systems now generate hundreds to thousands of vehicle tracks from raw data, with little human intervention. However, the tracking performance at this scale, is unreliable and average track length is much smaller than the average vehicle route. This is a limiting factor for applications which depend heavily on track identity, i.e. tracking vehicles from their points of origin to their final destination. In this paper we propose and investigate a framework for wide-area motion imagery (W AMI) exploitation that minimizes the dependence on track identity. In its current form this framework takes noisy, incomplete moving object detection tracks as input, and produces a small set of activities (e.g. multi-vehicle meetings) as output. The framework can be used to focus and direct human users and additional computation, and suggests a path towards high-level content extraction by learning from the human-in-the-loop.

  15. Fabric Active Transducer Stimulated by Water Motion for Self-Powered Wearable Device.

    Science.gov (United States)

    Kwon, Soon-Hyung; Kim, Won Keun; Park, Junwoo; Yang, YoungJun; Yoo, Byungwook; Han, Chul Jong; Kim, Youn Sang

    2016-09-21

    The recent trend of energy-harvesting devices is an adoption of fabric materials with flexible and stretchable according to the increase of wearable electronics. But it is a difficult process to form a core structure of dielectric layer or electrode on fabric materials. In particular, a fabric-based energy-harvesting device in contact with water has not been studied, though there are many challenging issues including insulation and water absorption in a harsh environment. So we propose an effective method to obtain an electrical energy from the water contact using our new fabric energy harvesting device. Our water motion active transducer (WMAT) is designed to obtain electrical energy from the variable capacitance through the movement and contact of water droplet. In this paper, we succeeded in generating an electrical energy with peak to peak power of 280 μW using a 30 μL of water droplet with the fabric WMAT device of 70 mm × 50 mm dimension. Furthermore, we specially carried out spray-coating and transfer processes instead of the conventional spin-coating process on fabric materials to overcome the limitation of its uneven morphology and porous and deformable assembly. PMID:27564593

  16. A framework for activity detection in wide-area motion imagery

    Science.gov (United States)

    Porter, Reid; Ruggiero, Christy; Morrison, John D.

    2009-05-01

    As wide-area persistent imaging systems become cost effective, increasingly large areas of the earth can be imaged at relatively high frame rates. Efficient exploitation of the large geo-spatial-temporal datasets produced by these systems poses significant technical challenges for image and video analysis and for data mining. Significant progress in image stabilization, moving object detection and tracking, are allowing automated systems to generate hundreds to thousands of vehicle tracks from raw data, with little human intervention. However, tracking performance at this scale is unreliable, and average track length is much smaller than the average vehicle route. These are limiting factors for applications that depend heavily on track identity, i.e. tracking vehicles from their points of origin to their final destination. In this paper, we propose and evaluate a framework for wide-area motion imagery (WAMI) exploitation that minimizes the dependence on track identity. In its current form, this framework takes noisy, incomplete moving object detection tracks as input, and produces a small set of activities (e.g. multi-vehicle meetings) as output. The framework can be used to focus and direct human users and additional computation, and suggests a path towards high-level content extraction by learning from the human-in-the-loop.

  17. Active-flux based motion sensorless vector control of biaxial excitation generator/motor for automobiles (BEGA)

    DEFF Research Database (Denmark)

    Coroban-Schramel, Vasile; Boldea, Ion; Andreescu, Gheorghe-Daniel;

    2009-01-01

    the active-flux concept the estimated rotor position is given by the sum of the active flux angle and torque angle. The active flux is calculated by subtracting the term Lq i s from the estimated stator flux vector. The experimental results validate the active flux-principle and show good performance......This paper proposes a novel, active-flux based, motion-sensorless vector control structure for biaxial excitation generator for automobiles (BEGA) for wide speed range operation. BEGA is a hybrid excited synchronous machine having permanent magnets on q-axis and a dc excitation on daxis. Using...

  18. Personalized Multilayer Daily Life Profiling Through Context Enabled Activity Classification and Motion Reconstruction: An Integrated System Approach.

    Science.gov (United States)

    Xu, James Y; Wang, Yan; Barrett, Mick; Dobkin, Bruce; Pottie, Greg J; Kaiser, William J

    2016-01-01

    Profiling the daily activity of a physically disabled person in the community would enable healthcare professionals to monitor the type, quantity, and quality of their patients' compliance with recommendations for exercise, fitness, and practice of skilled movements, as well as enable feedback about performance in real-world situations. Based on our early research in in-community activity profiling, we present in this paper an end-to-end system capable of reporting a patient's daily activity at multiple levels of granularity: 1) at the highest level, information on the location categories a patient is able to visit; 2) within each location category, information on the activities a patient is able to perform; and 3) at the lowest level, motion trajectory, visualization, and metrics computation of each activity. Our methodology is built upon a physical activity prescription model coupled with MEMS inertial sensors and mobile device kits that can be sent to a patient at home. A novel context-guided activity-monitoring concept with categorical location context is used to achieve enhanced classification accuracy and throughput. The methodology is then seamlessly integrated with motion reconstruction and metrics computation to provide comprehensive layered reporting of a patient's daily life. We also present an implementation of the methodology featuring a novel location context detection algorithm using WiFi augmented GPS and overlays, with motion reconstruction and visualization algorithms for practical in-community deployment. Finally, we use a series of experimental field evaluations to confirm the accuracy of the system. PMID:25546868

  19. 分期护理配合运动指导在全膝关节置换患者术后功能康复中的临床研究%Clinical research of staging nursing combined and motion guidance in postoperative function rehabilitation of patients with total knee replacement

    Institute of Scientific and Technical Information of China (English)

    李春花

    2014-01-01

    目的:探讨分期护理配合运动指导在全膝关节置换患者中的应用效果。方法将我院2008年1月至2013年1月进行全膝关节置换术的156例患者随机分为观察组和对照组,对照组采用常规护理,观察组在对照组的基础上进行分期护理联合运动指导,比较两组的自我管理能力、康复依从性、膝关节功能及护理满意度。结果观察组在饮食管理、心理管理、症状管理等方面的自我管理能力高于对照组,康复依从性高于对照组,有统计学意义( P<0.05)。观察组的护理满意度高于对照组,术后6周的膝关节功能评分、步行和上下楼梯评分均高于对照组,有统计学意义( P<0.05)。结论分期护理配合运动指导能够提高全膝关节置换术患者术后的康复依从性和病情管理能力,改善膝关节功能。%Objective To explore the application effect of staging nursing combined and motion guidance in patients with total knee replacement.Methods In our hospital from 2008 January to 2013 January 156 patients with total knee replacement were randomly divided into the observation group and the control group, the control group was received routine nursing care, the observation group was given staging nursing combined with exercise guidance based on the control group, and two groups were compared with self management ability, compli-ance with rehabilitation, the function of knee joint and nursing satisfaction.Results Diet management, psychological management, symp-toms ability and other aspects of self-management in the observation group were higher than those in the control group, compliance with re-habilitation was higher than that in the control group, with statistical significance (P<0.05) .Nursing satisfaction in the observation group was higher than that in the control group, the score of the function of knee joint, the scores of walking and stairs after 6 weeks were higher than those in the

  20. Outcome of knee injuries in general practice : 1-year follow-up

    NARCIS (Netherlands)

    Wagemakers, Harry P. A.; Luijsterburg, Pim A. J.; Heintjes, Edith M.; Berger, Marjolein Y.; Verhaar, Jan; Koes, Bart W.; Bierma-Zeinstra, Sita M. A.

    2010-01-01

    Background Knee injuries may lead to pain and to functional limitations in the activities of daily living. Patients with knee injuries are frequently seen in general practice; however, the outcome and management in these patients is not known. Aim To assess the outcome and management of knee injurie

  1. INFLUENCE OF GONARTHROSIS ON KINEMATICS INDICATORS OF THE KNEE JOINT

    Directory of Open Access Journals (Sweden)

    S. I. Loginov

    2016-01-01

    Full Text Available Aim. To establish peculiarity of the influence of gonarthrosis on kinematics indices of the knee joint at people at the age of 45–60 with the help of markless motion method.Materials and methods. In the research 81 people took part. In the group of the control entered 42 people without symptomatic evidences of gonarthrosis, in the experimental group – 39 people with gonarthrosis of the 1 and 2 degrees at the age of 40 to 65. With the help of the markless motion method and software Brekel Pro Body» was made biomechanical analysis of the kinematics of knee joints.Results. It is established that people at the age of 40 to 65, suffering with gonarthrosis have authentically more angular moments of lateral mode of motions and rotations in knee joints.Conclusion. Under analysis of the kinematics of knee joints, between the control and the experimental groups were fixed significant differences (t-test, p < 0,01. Besides there were fixed differences between dominant and non-dominant limbs, which mean that the force of muscles of lower limbs can also be a modificative factor, which influences on the strain in joints that potentially can lead to the development and/or advance of degenerative damage in the knee joint. 

  2. Bioinspired Knee Joint for a Power-Assist Suit

    Directory of Open Access Journals (Sweden)

    Takehito Kikuchi

    2016-01-01

    Full Text Available Movement of the knee joint of a human includes rolling and sliding. There also exist rotations in the frontal and horizontal planes. To assist the standing movement of a human, we developed a bioinspired knee joint and torque adjustment mechanism. We evaluated the motion, torque characteristics, and stress of the developed mechanism. This joint allows deep flexion of the knee with small resistance for both the user and the device. In addition, in spite of 33% error in deep flexion, the measured torque over less than 120 degrees fits the designed torque curve. We conducted evaluation tests for a human subject. The electromyogram (EMG of musculus rectus femoris was measured during standing with or without the assistance. The result shows 30% and 63% reduction with the assistance from 100-degree and 80-degree knee angles, respectively. In addition, the proposed device reduced up to 80% of stress in the frontal plane during standing.

  3. Inverse Dynamics and the Immeasurable Motions

    DEFF Research Database (Denmark)

    Rasmussen, John; Andersen, Michael Skipper; Damsgaard, Michael

    the precise 3-D marker locations, certain movements are inherently difficult to register, for instance the movement of the scapula relative to the thorax or glenohumeral superior migration. This paper, however, focuses on the knee. Knee flexion/extension is a large articulation in most practical cases......, typically gait, and a well-conducted experiment with a good-quality motion capture system will register this degree-of-freedom with sufficient accuracy for most applications. However, it is known from bone pin studies (Benoit et al. 2006) that the knee has significant movements additional to flexion...

  4. A Case Report on Bilateral Knee Coverage Following Septic Arthritis: Lateral Distal Thigh Island Flap and Medial Head Gastrocnemius Flap Methods

    Directory of Open Access Journals (Sweden)

    Abdolrazaghi

    2016-03-01

    Full Text Available Introduction Septic arthritis is the rheumatological and orthopedic emergency that causes the most difficulties with joints–especially knee and hip joints. The clinical symptoms include pain, swelling, inflammation, stiffness, and a limited range of motion in both active and passive joints. Debridement of the necrotic tissue is one beneficial method for septic arthritis treatment, although soft tissue defects around joints are a challenging issue for surgeons. Our purpose was to investigate the consequences of two flap surgery methods undertaken to repair soft tissue damaged during knee joint debridement caused by septic arthritis. Case Presentation This is a case report concerning a patient who had septic arthritis in the knee area and so underwent soft tissue surgery. The reconstruction methods were not the same for both knees as the lateral distal thigh island flap reparation method was used on the left knee and the medial head gastrocnemius flap method was utilized on the right. We then investigated the results and outcomes of the surgery three months later. Conclusions Lower extremity movement extent was carefully evaluated and, in respect to muscle strength, the patient was able to walk independently three months after the surgery. The patient’s balance was studied and the results showed moderate levels of stability.

  5. Contributory factors to the results of gravity-assisted pivot-shift test for anterior cruciate ligament injury: the significance of muscle torque around the knee.

    Science.gov (United States)

    Hiraoka, Hisatada; Yashiki, Motohisa; Sakai, Hiroya

    2008-03-01

    Gravity-assisted pivot-shift (GAPS) test is a newly advocated test for anterior cruciate ligament (ACL) injury. It induces anterolateral rotatory instability with valgus stress to the knee applied by gravitational force during patient's active knee motion. We investigated prospectively the relationships between the results of the GAPS test and the possible contributory factors and sought to clarify the determinant factors of the GAPS test. A total of 54 knee joints of 54 patients with unilateral ACL injury (29 males, 25 females, average 23.4 +/- 9.0 years old) were enrolled in this study and were divided into two groups, i.e., positive GAPS test group and negative GAPS test group. Muscle torque around the knee joints measured before surgery, configuration of the femoral condyle and tibial posterior slope angle measured on lateral radiograph, and other clinical factors were compared between the two groups using Mann-Whitney U test or chi-square test. According to the results of these analyses, factors having a statistically significant difference were additionally evaluated using multiple logistic regression analysis to reveal items with strong relevance to a positive GAPS test. The results of the multiple logistic regression analysis showed that the flexor/extensor peak torque ratio of contralateral uninjured knees and sex had a significant correlation with the results of the GAPS test. The relatively less flexor muscle torque compared with extensor muscle torque, and being a female patient were considered to be the determinant factors of a positive GAPS test.

  6. Clinical descriptive measures of shoulder range of motion for a healthy, young and physically active cohort

    Directory of Open Access Journals (Sweden)

    Vairo Giampietr L

    2012-09-01

    Full Text Available Abstract Background The objective of this innovative research study was to describe clinical shoulder complex range of motion (ROM measures for a young, healthy, and physically active population. This investigation represents a cross-sectional experiment conducted at a military academy-based sports medicine center. Military cadets with no history of shoulder complex injury were assessed within two months of enrollment in the academy; 548 men (18.8 ± 1.0 yr, 75.2 ± 12.2 kg, 178.3 ± 7.4 cm and 74 women (18.7 ± 0.9 yr, 63.2 ± 8.9 kg, 165.2 ± 6.9 cm participated. Descriptive measures included cross-body adduction (CAD, flexion (FLX, external rotation (ER0 with the shoulder complex in adduction and elbow flexed to 90°, internal and external rotation (IR, ER with the shoulder complex at 90° of abduction and elbow flexed to 90° as well as arc (ARC of IR-ER using standardized clinical quantification techniques. Bilateral and sex differences were evaluated using dependent and independent t-tests, respectively. Percentiles by arm dominance and sex were also calculated for all ROM measures. Results Data were normally distributed. Active and passive ROM measures indicated significant bilateral differences (P  Conclusions These original data provide descriptive measures for shoulder complex ROM excursions, assisting sports medicine practitioners in potentially identifying clinical deficiencies and functional outcomes following shoulder injury.

  7. Biomechanical analysis of fixed bearing and mobile bearing total knee prostheses

    OpenAIRE

    Urwin, Samuel

    2014-01-01

    In total knee replacement (TKR) surgery, mobile bearing (MB) total knee prostheses were designed to more closely mimic the function of the normal knee than traditional fixed bearing (FB) designs by allowing axial mobility between the polyethylene insert and tibial tray. Despite the hypothetical benefits of the MB design, few studies have objectively analysed knee biomechanics during activities of daily living (ADLs) in the laboratory compared to FB designs. This thesis aimed to substantiate t...

  8. [Osteochondritis dissecans of the knee].

    Science.gov (United States)

    Benedict, Shaike; Oron, Amir; Beer, Yiftah; Agar, Gavriel

    2008-07-01

    Osteochondritis dissecans of the knee is diagnosed at an increasing rate among adolescents and young adults. One of the reasons is due to the increasing number of sports participants among these populations. Although many theories exist, the cause of osteochondritis dissecans is unknown. Early diagnosis is very important. While adult type osteochondritis dissecans is unstable, in most young patients it is stable, and patients with an intact articular surface have a good chance to heal with non-operative treatment and cessation of physical activity. The value of complementary treatment (bed rest, partial weight bearing, bracing aimed at reducing weight bearing of the involved knee) is unknown. Patients with open physes and stable lesions, who failed non-operative treatment, may be treated with local bone drilling, encouraging lesion healing. As the disease progresses, more aggressive measures should to be taken, whilst decreasing success ratios are expected. The healing potential of the lesion may be evaluated by magnetic resonance imaging. Most adult type osteochondritis dissecans patients, as most young patients, with unstable lesions and loose bodies within their knees, are treated with fixation of the lesions and even bone grafting. Many unstable lesions will heal after fixation, but the long-term prognosis is elusive. Chronic loose bodies are very difficult to fix, with less favorable outcomes. Excision of large lesions originating from weight bearing cartilage is not favorable and different rehabilitation measures of local cartilage damage are not encouraging. PMID:18814522

  9. Human motion energy harvesting using a piezoelectric MFC patch.

    Science.gov (United States)

    Bassani, Giulia; Filippeschi, Alessandro; Ruffaldi, Emanuele

    2015-01-01

    The improvements in efficiency of electronic components and miniaturization is quickly pushing wearable devices. Kinetic human energy harvesting is a way to power these components reducing the need of batteries replacement since walking or running is how humans already expend much of their daily energy. This work explores the case of kinetic energy from bending of a piezoelectric patch. For assessing the quality of the system, a testing setup has been designed and controlled by means of knee joint recordings obtained from a large motion dataset. The promising result of the chosen patch is an output power of 2.6μW associated to a run activity. PMID:26737431

  10. Ground motion parameters of Shillong plateau: One of the most seismically active zones of northeastern India

    Institute of Scientific and Technical Information of China (English)

    Saurabh Baruah; Santanu Baruah; Naba Kumar Gogoi; Olga Erteleva; Felix Aptikaev; J.R.Kayal

    2009-01-01

    Strong ground motion parameters for Shillong plateau of northeastern India are examined. Empirical relations are obtained for main parameters of ground motions as a function of earthquake magnitude, fault type, source depth, velocity characterization of medium and distance. Correlation between ground motion parameters and characteristics of seismogenic zones are established. A new attenuation relation for peak ground acceleration is developed, which predicts higher expected PGA in the region. Parameters of strong motions, particularly the predominant periods and duration of vibrations, depend on the morphology of the studied area. The study measures low estimates of logarithmic width in Shillong plateau. The attenuation relation estimated for pulse width critically indicates increased pulse width dependence on the logarithmic distance which accounts for geometrical spreading and anelastic attenuation.

  11. Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

    Science.gov (United States)

    Hendry, D; Campbell, A; Ng, L; Grisbrook, T L; Hopper, D M

    2015-12-01

    Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower-limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain-free 12-15-year-old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower-limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers. PMID:25091570

  12. Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

    Science.gov (United States)

    Hendry, D; Campbell, A; Ng, L; Grisbrook, T L; Hopper, D M

    2015-12-01

    Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower-limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain-free 12-15-year-old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower-limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

  13. Influence of surface active substances on bubble motion and collision with various interfaces.

    Science.gov (United States)

    Malysa, K; Krasowska, M; Krzan, M

    2005-06-30

    Bubble motion as a function of distance from a point of its detachment and phenomena occurring during the bubble approach and collision with liquid/gas and liquid/solid interfaces in pure water and solutions of various surface active substances are described and discussed. It is showed that presence of surface active substance has a profound influence on values of the terminal velocity and profiles of the local velocity. At low solutions concentrations there are three distinct stages in the bubble motion: (i) a rapid acceleration, (ii) a maximum velocity value followed by its monotonic decrease, and (iii) attainment of the terminal velocity, while at high concentrations (and in pure water) there are only stages (i) and (iii). It is showed that the bubble terminal velocity decreases rapidly at low surfactant concentration, but there can be found some characteristic concentrations (adsorption coverage's) above which the velocity almost stopped to decrease. Immobilization of the bubble surface resulting from adsorption of the surface active substances (surface tension gradients inducement) causes over twofold lowering of the bubble velocity. Presence of the maximum on the local velocity profiles is an indication that a stationary non-uniform distribution of adsorption coverage (needed for immobilization the bubble interface) was not established there. When the rising bubble arrives at liquid/gas interface or liquid/solid interface there can be formed either foam or wetting film or three-phase contact (TPC). It is showed that prior to the foam and/or wetting film formation the bubble colliding with the interfaces can bounce backward and simultaneously its shape pulsates rapidly with a frequency over 1000 Hz. It is rather unexpected that even in the case of the free surface the bubble's shape and consequently its surface area can vary so rapidly. It shows straightforward that on such a rapidly distorted interface the adsorption coverage can be very different from that

  14. Combined anterior cruciate ligament and posterolateral reconstruction of the knee using allograft tissue in chronic knee injuries.

    Science.gov (United States)

    Fanelli, Gregory C; Fanelli, David G; Edson, Craig J; Fanelli, Matthew G

    2014-10-01

    Combined anterior cruciate ligament (ACL) and posterolateral injury of the knee can result in significant functional instability for the affected individual. Both components of the instability must be treated to maximize the probability of success for the surgical procedure. Higher failure rates of the ACL reconstruction have been reported when the posterolateral instability has been left untreated. The purpose of this article is to describe our surgical technique, and present the results of 34 chronic combined ACL posterolateral reconstructions in 34 knees using allograft tissue, and evaluating these patient outcomes with KT 1000 knee ligament arthrometer, Lysholm, Tegner, and Hospital for Special Surgery knee ligament rating scales. In addition, observations regarding patient demographics with combined ACL posterolateral instability, postoperative range of motion loss, postinjury degenerative joint disease, infection rate, return to function, and the use of radiated and nonirradiated allograft tissues will be presented.

  15. Combined anterior cruciate ligament and posterolateral reconstruction of the knee using allograft tissue in chronic knee injuries.

    Science.gov (United States)

    Fanelli, Gregory C; Fanelli, David G; Edson, Craig J; Fanelli, Matthew G

    2014-10-01

    Combined anterior cruciate ligament (ACL) and posterolateral injury of the knee can result in significant functional instability for the affected individual. Both components of the instability must be treated to maximize the probability of success for the surgical procedure. Higher failure rates of the ACL reconstruction have been reported when the posterolateral instability has been left untreated. The purpose of this article is to describe our surgical technique, and present the results of 34 chronic combined ACL posterolateral reconstructions in 34 knees using allograft tissue, and evaluating these patient outcomes with KT 1000 knee ligament arthrometer, Lysholm, Tegner, and Hospital for Special Surgery knee ligament rating scales. In addition, observations regarding patient demographics with combined ACL posterolateral instability, postoperative range of motion loss, postinjury degenerative joint disease, infection rate, return to function, and the use of radiated and nonirradiated allograft tissues will be presented. PMID:24949986

  16. Knee arthroscopy - series (image)

    Science.gov (United States)

    ... usually able to leave the hospital after arthroscopic knee surgery within 24 hours of surgery. The recovery time, and the need for physical therapy after surgery are determined by the injury treated ...

  17. What Are Knee Problems?

    Science.gov (United States)

    ... Health Information Basics for You and Your Family Sports Injuries, Handout on Health Health Information Knee Problems Find ... for a long time. This sometimes occurs in sports training. Treatment for tendon injuries and disorders includes: Rest Ice Elevation Medicines such ...

  18. Jumper's Knee (Patellar Tendonitis)

    Science.gov (United States)

    ... when bending the knee pain in the quadriceps muscle leg or calf weakness Less common symptoms include: balance problems warmth, ... weight-bearing muscle groups like the quadriceps and calf muscles specialized injections to desensitize nerve endings and reduce ...

  19. Revision Knee Surgery

    Medline Plus

    Full Text Available ... LPS flex to LCCK components, to even a rotating hinge knee arthroplasty, and finally, to the segmental ... I think the interface stresses, even with the rotating hinges, are higher, and so I want fixation ...

  20. Revision Knee Surgery

    Medline Plus

    Full Text Available ... Tiarina [PH], Angie Weems [PH], and to my right, Roya Royo [PH]. Elise Bond Is our circulator. ... female, five- three, 274 pounds, who had this right knee replacement performed approximately ten years ago. Initially ...

  1. Revision Knee Surgery

    Medline Plus

    Full Text Available ... equally bad. Right. So what about you rehab process for this knee? Does it change in any manner to your primary setting? Not really. The pain management protocol that we have here is excellence. The ...

  2. Stance control knee mechanism for lower-limb support in hybrid neuroprosthesis

    Directory of Open Access Journals (Sweden)

    Curtis S. To, PhD

    2011-08-01

    Full Text Available A hydraulic stance control knee mechanism (SCKM was developed to fully support the knee against flexion during stance and allow uninhibited motion during swing for individuals with paraplegia using functional neuromuscular stimulation (FNS for gait assistance. The SCKM was optimized for maximum locking torque for body-weight support and minimum resistance when allowing for free knee motion. Ipsilateral and contralateral position and force feedback were used to control the SCKM. Through bench and nondisabled testing, the SCKM was shown to be capable of supporting up to 70 N-m, require no more than 13% of the torque achievable with FNS to facilitate free motion, and responsively and repeatedly unlock under an applied flexion knee torque of up to 49 N-m. Preliminary tests of the SCKM with an individual with paraplegia demonstrated that it could support the body and maintain knee extension during stance without the stimulation of the knee extensor muscles. This was achieved without adversely affecting gait, and knee stability was comparable to gait assisted by knee extensor stimulation during stance.

  3. The Effect of Hip Bracing on Gait in Patients with Medial Knee Osteoarthritis

    Directory of Open Access Journals (Sweden)

    David Wallace

    2012-01-01

    Full Text Available Objective. Impaired hip motion has been associated with heightened medial knee joint loading in patients with knee osteoarthritis (OA. A hip external rotation strap designed to pull the femur into external rotation and abduction may serve as one protective mechanism. The primary aim of our study is to determine if the strap decreases medial knee joint loading during level walking in people with knee OA. Design. This study is a single-day repeated measures design. Methods. 15 volunteers with medial knee OA underwent motion analysis data collection during two randomly assigned walking conditions: (1 wearing the strap and (2 control (no strap. Primary outcome measures were peak pelvis, hip and knee joint motions, and torques. These outcomes were averaged across five trials for each condition. Results. Hip abduction (<0.01, trunk lean towards the stance limb (=0.04 and pelvic tilt (=0.02 significantly increased with the strap versus control trials. Knee adduction loading did not significantly change with the strap (=0.33. Conclusion. The use of the hip external rotation strap resulted in angular changes at the hip and pelvis which may be beneficial for patients with medial knee osteoarthritis.

  4. Reading Knee-Deep

    Science.gov (United States)

    Jewett, Pamela

    2007-01-01

    Freire told his audience at a seminar at the University of Massachusetts, "You need to read knee-deep in texts, for deeper than surface meanings, and you need to know the words to be able to do it" (quoted in Cleary, 2003). In a children's literature class, fifteen teachers and I traveled along a path that moved us toward reading knee-deep as we…

  5. Elastic Knee Sleeves Limit Anterior Tibial Translation in Healthy Females

    Directory of Open Access Journals (Sweden)

    Robert Csapo, Simona Hosp, Ramona Folie, Robert Eberle, Michael Hasler, Werner Nachbauer

    2016-03-01

    Full Text Available Knee sleeves or braces represent auxiliary tools that have repeatedly been used by athletes, in an attempt to increase knee stability and, thus, reduce the risk of (recurrent ligamentous injuries. Since ACL injuries typically occur in situations involving either torsion or hyperextension of the knee, it has been speculated that braces might protect the ACL by countering excessive anterior translation of the tibia with respect to the femur (Beynnon et al., 1997. However, the preponderance of in vivo studies to test this hypothesis was performed in cohorts of patients suffering from existent ligamentous (Branch et al., 1988; Colville et al., 1986 or other knee injury (Beynnon et al., 1997; Fleming et al., 2000. This complicates the extrapolation of results to healthy subjects. Further, the braces used in these studies were mostly rigid constructs that consisted of either uni- or bilateral hinged bars (Rishiraj et al., 2009. Such braces might hinder performance (Veldhuizen et al., 1991 and would be rejected by the vast majority of healthy athletes. For these reasons, we would like to use this letter to the editor to report the results of our experiments investigating whether a relatively light elastic knee sleeve would limit the degree of anterior tibial translation in computerized arthrometry tests as performed in a sample of non-injured subjects. We recruited ten female college students (age: 23.4 ± 3.2 yrs, height: 1.68 ± 0.05 m, mass: 59.9 ± 5.5 kg who were free of acute or previous injury or any form of orthopaedic disease of the knee joints. The anterior displacement of the tibia was measured using the GNRB® computerized arthrometer (GeNouRob, Laval, France. With subjects lying in the supine position, the lower leg was firmly fixed with plastic caps mounted over the ankle joint and patella. An electrical pressure pad then exerted increasing pressure of up to 250 N on the calf, while a motion sensor, which was positioned on the ventral

  6. Effect of knee joint angle on side-to-side strength ratios.

    Science.gov (United States)

    Krishnan, Chandramouli; Williams, Glenn N

    2014-10-01

    Isometric knee extensor and flexor strength are typically tested at different joint angles due to the differences in length-tension relationships of the quadriceps and hamstring muscles. The efficiency of strength testing can be improved if the same angle can be used to test both the knee extensor and flexor muscle groups. The aim of this study was to determine an optimal angle for isometric knee strength testing by examining the effect of knee angle on side-to-side peak torque ratios. Eighteen active young people (9 males and 9 females) participated in this study. Knee extensor and knee flexor strength were tested on both sides at 30°, 60°, and 90° of knee flexion. The effect of knee flexion angle on side-to-side peak torque ratios, raw torque values, and side-to-side flexor-to-extensor torque ratios were assessed. Side-to-side knee extensor peak torque ratios and knee flexor-to-extensor torque ratios differed significantly by knee flexion angle (p = 0.024 and p = 0.011, respectively), but side-to-side knee flexor peak torque ratios did not differ significantly (p = 0.311). When considering both side-to-side peak torque ratios and flexor-to-extensor torque ratios, the values were more symmetrical (i.e., closer to 100%) only at 60° of knee flexion. Our results indicate that both the knee flexors and the knee extensors can be tested clinically at 60° of knee flexion. Our results also indicate that the hamstrings can be tested at any of the 3 angles if the examiner is interested in side-to-side ratios rather than raw torque values. These results may facilitate more efficient and flexible clinical knee strength testing.

  7. Human Control Law and Brain Activity of Voluntary Motion by Utilizing a Balancing Task with an Inverted Pendulum

    Directory of Open Access Journals (Sweden)

    Satoshi Suzuki

    2010-01-01

    Full Text Available Human characteristics concerning voluntary motion control are investigated, because this motion is fundamental for the machine operation and human-computer system. Using a force feedback haptic device and a balancing task of a virtual inverted pendulum, participants were trained in the task, and hand motion/force was measured, and brain activity was monitored. First, through brain analysis by near-infrared spectroscopy (NIRS and motion analysis of the pendulum, we identified a participant who was the most expert. Next, control characteristics of the most expert were investigated by considering the operational force and delay factor of a human. As a result, it was found that predictive control based on velocity information was used predominantly although a perception feedback control against the pendulum posture worked. And it was shown that an on-off intermittency control, which was a strategy for the skilled balancing, can be described well by a liner model involving two types of time shifts for the position and velocity. In addition, it was confirmed that the cortex activity for observation in an ocular motor control area and visual processing area was strong to enhance above-mentioned control strategies.

  8. Energy harvesting from walking motion of a humanoid robot using a piezoelectric composite

    Science.gov (United States)

    Cha, Youngsu; Hong, Seokmin

    2016-10-01

    In this paper, we investigate the energy harvesting of a piezoelectric composite in a knee pad during walking motion. We use a humanoid robot as a test bed for the experiments using the knee pad. The humanoid wears the knee pad hosting the piezoelectric composite, and its operating knee motion mimics the walking based on the data captured from a human. The use of the humanoid enables the motion to be completely repeatable. We quantitatively study the energy harvesting by using the repeated motion. An electromechanical model for the piezoelectric energy harvester is used to estimate power transferred to varied load resistances under the repeated knee motion. With a good agreement between the experiments and the model predictions, we demonstrate power harvesting on the order of ten microWatts.

  9. Knee pain in competitive swimming.

    Science.gov (United States)

    Rodeo, S A

    1999-04-01

    The high volume of training in competitive swimming results in cumulative overload injuries. Knee pain ranks second to shoulder pain as a common complaint in competitive swimmers. Most knee pain occurs on the medial side of the knee and, most commonly, in breaststroke swimmers; however, knee pain may accompany all strokes. This article reviews the incidence of knee pain, the biomechanic and anatomic factors predisposing to injury, specific injury patterns, injury diagnosis, and the treatment and prevention of injury to the knee in swimmers. PMID:10230572

  10. Active control of the attitude motion and structural vibration of a flexible satellite by jet thrusters

    Science.gov (United States)

    Lee, Mokin

    A Lagrangian formulation is used to obtain the equations of motion of a flexible satellite in a tree-type geometry. The flexible satellite model is the geosynchronous INSAT-II type satellite with a flexible balance beam and a flexible solar panel attached to the rigid main body. In deriving the equations of motion, the orbital motion, the librational motion, and the structural motion of flexible bodies are involved. The assumed-modes method is used to express the deflections of the flexible structures in the form of a finite series of space-dependent admissible functions multiplied by time-dependent amplitudes. The kinetic energy, potential energy, strain energy, and virtual work of the flexible satellite are evaluated as functions of time in terms of the generalized coordinates. Then, by substituting them into Lagrange's equations for discrete systems, the governing equations of motion of the flexible satellite are obtained as a set of second-order nonlinear ordinary differential equations. The attitude motion and the structural motion of the flexible satellite are coupled motions with one another. Uncontrolled dynamics show that the librational and structural motions are oscillatory and undamped motions. The stability and performance of the flexible satellite needs to be improved by designing control systems. A control objective is proposed to improve the stability and performance for pointing accuracy maneuver by controlling the librational motions and flexible modes simultaneously. For the control objective, a control system is synthesized, using feedback linearization control, thrust determination, thrust management, and pulse-width pulse-frequency modulation. Feedback linearization for second-order nonlinear systems is used to obtain a stable feedback control system for the pointing-accuracy control. A stable feedback control system is obtained by adjusting the diagonal matrices of the linear second-order system. Jet thrusters are used as the primary

  11. Immediate effects of unilateral restricted ankle motion on gait kinematics in healthy subjects.

    Science.gov (United States)

    Romkes, Jacqueline; Schweizer, Katrin

    2015-03-01

    Correcting a pathological toe walking gait pattern can be achieved by restricting excessive plantarflexion during the swing phase of gait. A common conservative treatment measure is providing the patient with an ankle-foot-orthosis on the affected lower leg. This study examined the lower body gait kinematics and temporal-spatial parameters of fifteen healthy adults when walking freely and with unilateral restricted ankle motion. The latter was achieved by fitting an ankle-foot-orthosis. Specific hip and knee kinematic parameters and temporal-spatial parameters were investigated. Differences between the two conditions were calculated by paired Student's t-tests and 95% confidence intervals. Unilateral restricted ankle motion influenced kinematics mainly in the swing phase. Hip and knee peak flexion in the swing phase were increased on the restricted side (hip: 49.2° (SD 4.2°), knee: 75.9° (SD 6.1°)) compared to walking freely (hip: 43.3° (SD 4.5°), knee: 66.7° (SD 5.3°)). Peak hip flexion occurred earlier in the swing phase in the restricted condition (85% (SD 2%)) compared to the free-walking condition (96% (SD 5%)). For these parameters, the confidence intervals were different, indicating clinical relevance. Walking with unilateral restricted ankle motion had a negative effect on walking velocity, cadence, step time, and step length. The confidence intervals, however, overlapped. These results might be a reaction to unusual sensory feedback from the feet with the ankle-foot-orthosis or due to increased hip flexor activity compensating for the reduced function of the plantarflexors. The evaluation of the immediate changes in unilateral restricted ankle motion in individuals with healthy gaits can contribute to a more complete understanding on this topic. PMID:25800648

  12. Relationship between static anterior laxity using the KT-1000 and dynamic tibial rotation during motion in patients with anatomical anterior cruciate ligament reconstruction.

    Science.gov (United States)

    Sato, Koji; Maeda, Akira; Takano, Yoshio; Matsuse, Hiroo; Ida, Hirofumi; Shiba, Naoto

    2013-01-01

    The anterior cruciate ligament (ACL) plays an important role in controlling knee joint stability, not only by limiting tibial anterior translation but also by controlling knee axial rotation. The aim of ACL reconstruction is to reduce excessive anterior joint laxity, hoping to restore normal tibiofemoral kinematics including knee axial rotation. The purpose of this study was to investigate the relationship between static anterior instability and tibial rotation during several activities in an anterior cruciate ligament reconstructed knee. Seven patients with unilateral ACL injury performed plain walking, running, landing and side step cutting tasks after ACL reconstruction with a mean follow-up of 14 months. The kinematic data for the 4 motions was measured using a motion analysis system and the point cluster technique. The evaluation period was defined to be from the first contact to removal of the tested leg from the ground. Maximum tibial internal rotation during tasks was calculated using the point cluster technique (PCT). Passive anterior tibial translation was measured using a KT-1000 arthrometer. Regression analysis was used to determine the correlation of the maximum internal rotation with the side-to-side difference of static anterior tibial translation measured using a KT-1000 arthrometer. During side step cutting maneuvers, maximum tibial internal rotation significantly showed negative correlation with static anterior tibial translation (pknee rotation kinematics. The normal anterior tibial translation obtained by ACL reconstruction is thought to be the key factor in successful restoration of normal knee kinematics. PMID:23925154

  13. Are both the knees of the same size? Analysis of component asymmetry in 289 bilateral knee arthroplasties

    Directory of Open Access Journals (Sweden)

    Venkata Gurava Reddy

    2011-01-01

    Full Text Available Background: Variations in the anatomy of knee are well described, however the true incidence of component asymmetry in bilateral total knee arthroplsties is rarely reported. Incidence of component asymmetry in bilateral total knee arthroplasties (TKA was retrospectively analysed in 289 cruciate retaining total knee arthroplasties. Materials and Methods: Medical records of these 289 patients were evaluated for the incidence of asymmetry of either femoral or tibial components. Clinical outcomes were compared between the cases of asymetrical components to that of symmetrical components. Results: Incidence of femoral component asymmetry was found to be 9.2% and tibial component asymmetry to be 8.7%. Of 289 cases, TKA 178 were done in a single day (group A, while 111 were done at 2- to 3-day intervals (group B. Asymmetric and symmetric knees were equally distributed among both groups, male and female patients in both groups, and the incidence of component asymmetry was similar between all four different implants - Optetrak-CR (Exactech, Gainesville, FL, USA, Nexgen-CR (Zimmer, Warsaw, IN, USA, PFC-Sigma CR (DePuy, Warsaw, IN, USA, Genesis II CR (Smith and Nephew, Memphis, TN, USA we used. The pre- and postoperative range of motion and pre- and postoperative knee society scores were compared between the symmetric and asymmetric cases in both the groups and the difference was found to be insignificant. Conclusion: We conclude that incidence of component asymmetry in bilateral total knee arthroplasty is around 9 % and independent sizing of both knees during bilateral arthoplasty is recommended rather than simply relying on the contralateral knee measurements.

  14. Parallax-sensitive remapping of visual space in occipito-parietal alpha-band activity during whole-body motion.

    Science.gov (United States)

    Gutteling, T P; Selen, L P J; Medendorp, W P

    2015-03-01

    Despite the constantly changing retinal image due to eye, head, and body movements, we are able to maintain a stable representation of the visual environment. Various studies on retinal image shifts caused by saccades have suggested that occipital and parietal areas correct for these perturbations by a gaze-centered remapping of the neural image. However, such a uniform, rotational, remapping mechanism cannot work during translations when objects shift on the retina in a more complex, depth-dependent fashion due to motion parallax. Here we tested whether the brain's activity patterns show parallax-sensitive remapping of remembered visual space during whole-body motion. Under continuous recording of electroencephalography (EEG), we passively translated human subjects while they had to remember the location of a world-fixed visual target, briefly presented in front of or behind the eyes' fixation point prior to the motion. Using a psychometric approach we assessed the quality of the memory update, which had to be made based on vestibular feedback and other extraretinal motion cues. All subjects showed a variable amount of parallax-sensitive updating errors, i.e., the direction of the errors depended on the depth of the target relative to fixation. The EEG recordings show a neural correlate of this parallax-sensitive remapping in the alpha-band power at occipito-parietal electrodes. At parietal electrodes, the strength of these alpha-band modulations correlated significantly with updating performance. These results suggest that alpha-band oscillatory activity reflects the time-varying updating of gaze-centered spatial information during parallax-sensitive remapping during whole-body motion. PMID:25505108

  15. Three-dimensional knee kinematics by conventional gait analysis for eleven motor tasks of daily living: typical patterns and repeatability.

    Science.gov (United States)

    Scheys, Lennart; Leardini, Alberto; Wong, Pius D; Van Camp, Laurent; Callewaert, Barbara; Bellemans, Johan; Desloovere, Kaat

    2013-04-01

    The availability of detailed knee kinematic data during various activities can facilitate clinical studies of this joint. To describe in detail normal knee joint rotations in all three anatomical planes, 25 healthy subjects (aged 22-49 years) performed eleven motor tasks, including walking, step ascent and descent, each with and without sidestep or crossover turns, chair rise, mild and deep squats, and forward lunge. Kinematic data were obtained with a conventional lower-body gait analysis protocol over three trials per task. To assess the repeatability with standard indices, a representative subset of 10 subjects underwent three repetitions of the entire motion capture session. Extracted parameters with good repeatability included maximum and minimum axial rotation during turning, local extremes of the flexion curves during gait tasks, and stride times. These specific repeatable parameters can be used for task selection or power analysis when planning future clinical studies.

  16. Mechanically Activated Motion of a Single Self-Propelled Polymeric Microcapsule

    Science.gov (United States)

    Kolmakov, German; Schaefer, Alexander; Aranson, Igor; Balazs, Anna

    2011-03-01

    Using a hybrid computational approach, we demonstrate that a single nanoparticle-filled microcapsule on a rigid substrate can undergo self-sustained motion in response to initial mechanical deformation. Nanoparticles released from the capsule modify the underlying substrate and the adhesion gradients of the nanoparticle concentration formed at the surface sustain the motion of the capsule. The permeability of the microcapsule's shell increases with its deformation and therefore, more deformed microcapsules release nanoparticles at higher rates. An initial, non-uniform mechanical deformation of the capsule by an applied force causes an asymmetry in the nanoparticle distribution on the substrate that initiates the microcapsule motion. We also develop a two-dimensional model of the phenomenon within the phase-field approximation and compare the results of the two approaches.

  17. Design and evaluation of a new type of knee orthosis to align the mediolateral angle of the knee joint with osteoarthritis.

    Science.gov (United States)

    Esrafilian, Amir; Karimi, Mohammad Taghi; Eshraghi, Arezoo

    2012-01-01

    Background. Osteoarthritis (OA) is a disease which influences the performance of the knee joint. Moreover, the force and moments applied on the joint increase in contrast to normal subjects. Various types of knee orthoses have been designed to solve the mentioned problems. However, there are other problems in terms of distal migration during walking and the alignment of the orthosis which cannot be changed following the use of brace. Therefore, the main aim of the research was to design an orthosis to solve the aforementioned problems. Method. A new type of knee orthosis was designed with a modular structure. Two patients with knee OA participated in this research project. The force applied on the foot, moment transmitted through the knee joint, and spatiotemporal gait parameters were measured by use of a motion analysis system. Results. The results of the research showed that the adduction moment applied on the knee joint decreased while subjects walked with the new knee orthosis (P-value knee brace can be used as an effective treatment to decrease the loads applied on the knee joint and to improve the alignment whilst walking.

  18. Design and Evaluation of a New Type of Knee Orthosis to Align the Mediolateral Angle of the Knee Joint with Osteoarthritis

    Directory of Open Access Journals (Sweden)

    Amir Esrafilian

    2012-01-01

    Full Text Available Background. Osteoarthritis (OA is a disease which influences the performance of the knee joint. Moreover, the force and moments applied on the joint increase in contrast to normal subjects. Various types of knee orthoses have been designed to solve the mentioned problems. However, there are other problems in terms of distal migration during walking and the alignment of the orthosis which cannot be changed following the use of brace. Therefore, the main aim of the research was to design an orthosis to solve the aforementioned problems. Method. A new type of knee orthosis was designed with a modular structure. Two patients with knee OA participated in this research project. The force applied on the foot, moment transmitted through the knee joint, and spatiotemporal gait parameters were measured by use of a motion analysis system. Results. The results of the research showed that the adduction moment applied on the knee joint decreased while subjects walked with the new knee orthosis (P-value < 0.05. Conclusion. The new design of the knee brace can be used as an effective treatment to decrease the loads applied on the knee joint and to improve the alignment whilst walking.

  19. Active Motion of Tectonic Blocks in East Asia: Evidence from GPS Measurement

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The relative Euler vectors of the Pacific, Philippine, Amurian, Okhotsk, N. Honshu and South China plates or blocks are deduced from earthquake slip vectors, transform fault azimuths and spreading rates, which are consistent with new results derived from the International Terrestrial Reference Frame ITRF2000 velocity field, the velocity field of GPS stations in China and the GPS measurement data of the GEONET network in Japan. Based on the two groups of Euler vectors, analysis and comparative study of the relative motions and deformations of the tectonic blocks in East Asia reveal the present-day motion characteristics of the blocks.

  20. 有限切开加自体腱移植修复膝关节韧带损伤:明显改善膝关节功能%Limited incision plus autologous tendon graft improve knee joint functions in the treatment of knee ligament injuries

    Institute of Scientific and Technical Information of China (English)

    崔宙开; 申海生; 赵雅莉

    2014-01-01

    文章亮点:  1试验所采用的有限切开加自体腱移植治疗方法,主要在关节镜下进行操作,术野十分清晰,韧带损伤部位及范围可准确确定。  2文章结果显示,有限切开加自体腱移植修复膝关节韧带损伤疗效显著,可明显改善膝关节功能和生活质量。%BACKGROUND:Early diagnosis and accurate treatment of ligament injuries are the premise of avoiding chronic instability of knee joint and promoting functional recovery of knee joint. OBJECTIVE:To investigate the clinical efficacy of limited incision with autologous tendon graft for knee ligament injury. METHODS:Eighty patients with knee ligament damage were randomly divided into two groups. The cases of control group were given orthosis treatment, and the cases of observation group were treated with the limited incision plus autologous tendon graft. RESULTS AND CONCLUSION:At 6 months post-treatment, the excellent efficacy rate and postoperative quality of life score were increased in the observation group, compared with the control group (P<0.05). The active and passive ranges of motion of knee joint in the observation group were significantly lower than that in the control group (P<0.05). At 3 months post-treatment, Lysholmp scores of the observation group was significantly lower than that in the control group (P<0.05). Limited incision plus autologous tendon graft treatment can significantly improve knee function after knee ligament injury.

  1. Avoidance of activity and disability in patients with osteoarthritis of the knee: the mediating role of muscle strength.

    NARCIS (Netherlands)

    Steultjens, M.P.M.; Dekker, J.; Bijlsma, J.W.J.

    2002-01-01

    OBJECTIVE: Avoidance of activity is hypothesized to lead to muscle weakness and consequently, to physical disability. This study was undertaken to validate the avoidance model by providing evidence for the mediating role of muscle weakness in the relationship between avoidance of activity and physic

  2. Assessment of Knee Proprioception in the Anterior Cruciate Ligament Injury Risk Position in Healthy Subjects: A Cross-sectional Study

    OpenAIRE

    Mir, Seyed Mohsen; Talebian, Saeed; Naseri, Nasrin; Hadian, Mohammad-Reza

    2014-01-01

    [Purpose] Knee joint proprioception combines sensory input from a variety of afferent receptors that encompasses the sensations of joint position and motion. Poor proprioception is one of the risk factors of anterior cruciate ligament injury. Most studies have favored testing knee joint position sense in the sagittal plane and non-weight-bearing position. One of the most common mechanisms of noncontact anterior cruciate ligament injury is dynamic knee valgus. No study has measured joint posit...

  3. Total Knee Replacement for Women

    Medline Plus

    Full Text Available ... ll be moderating a Zimmer Gender Solutions total knee, performed by my partner, Dr. Ken Gustke. At ... I’m going to be doing a total knee replacement utilizing the Gender Flex implants on a ...

  4. MedlinePlus: Knee Replacement

    Science.gov (United States)

    ... Knee Pain and the Weekend Warriors (OR-Live) - Mercy Hospital, Miami, FL, 3/17/2009 Also in ... 2012 Small Incision Total Knee Arthroplasty (OR-Live) - Mercy Hospital, Miami, FL, 3/01/2011 Also in ...

  5. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... ligaments well balanced, that almost any knee will work. But if we'll maximize and think about ... and cam design which allow this knee to work will in high flexion without the threat of ...

  6. Application of a novel spinal posture and motion measurement system in active and static sitting.

    Science.gov (United States)

    Pries, Esther; Dreischarf, Marcel; Bashkuev, Maxim; Schmidt, Hendrik

    2015-01-01

    The quantification of work-related musculoskeletal risk factors is of great importance; however, only a few tools allow objective, unrestricted measurements of spinal posture and motion in workplaces. This study was performed to evaluate the applicability of the Epionics system in a sedentary workplace. The system is mobile and wireless and assesses lumbar lordosis, pelvic orientation and spinal motion, without restricting subjects in their movements. In total, 10 males were monitored while sitting for 2 h on static and dynamic office chairs and on an exercise ball, to evaluate the effect of dynamic sitting. The volunteers were able to perform their work unhampered. No differences among the tested furniture could be detected with respect to either the lordosis or the number of spinal movements after habituation to the furniture; however, differences in pelvic orientation were statistically significant. The results of the present study indicate that Epionics may be useful for the quantitative assessment of work-related risk factors. Practitioner Summary: Only a few tools allow objective, unrestricted measurements of spinal posture and motion in the workplace. Epionics SPINE measures lumbar lordosis, pelvic orientation and spinal motion under nearly unrestricted conditions and can be used to quantify work-related musculoskeletal risk factors. We demonstrated the use of this tool in the workplace-analysis. PMID:25712870

  7. Dynamic gadolinium-enhanced magnetic resonance imaging allows accurate assessment of the synovial inflammatory activity in rheumatoid arthritis knee joints: a comparison with synovial histology

    DEFF Research Database (Denmark)

    Axelsen, Mette Bjørndal; Stoltenberg, M.; Poggenborg, R.;

    2012-01-01

    Objective: To determine whether dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) evaluated using semi-automatic image processing software can accurately assess synovial inflammation in rheumatoid arthritis (RA) knee joints. Methods: In 17 RA patients undergoing knee surgery...... capsule of the knee joint (Precise ROI). Intra- and interreader agreement was assessed using the intra-class correlation coefficient (ICC). Results: The IRE from the Quick ROI and the Precise ROI revealed high correlations to the grade of histological inflammation (Spearman's correlation coefficient (rho...... (IRE), were generated by the software in three different areas: (I) the entire slice (Whole slice); (II) a manually outlined region of interest (ROI) drawn quickly around the joint, omitting large artefacts such as blood vessels (Quick ROI); and (III) a manually outlined ROI following the synovial...

  8. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... the NexGen® LPS-Flex Mobile and LPS-Mobile Bearing Knees March 5, 2009 Welcome to this "OR ... MIS total knee arthroplasty with the Zimmer mobile bearing knee. We invite all of you who have ...

  9. Minimally Invasive Total Knee Arthroplasty

    Medline Plus

    Full Text Available ... NexGen® LPS-Flex Mobile and LPS-Mobile Bearing Knees March 5, 2009 Welcome to this "OR Live" ... re going to be doing an MIS total knee arthroplasty with the Zimmer mobile bearing knee. We ...

  10. Biomechanical risk factors and mechanisms of knee injury in golfers.

    Science.gov (United States)

    Marshall, Robert N; McNair, Peter J

    2013-09-01

    Knee injuries in golf comprise approximately 8% of all injuries, and are considered to result from overuse, technical faults or a combination of those factors. This review examines factors involved in injury, including the structure of the knee joint, kinematics and kinetics of the golf swing, forces sustained by knee joint structures and the potential for joint injury as well as injury prevention strategies. The golf swing generates forces and torques which tend to cause internal or external rotation of the tibia on the femur, and these are resisted by the knee ligaments and menisci. Research has shown that both maximum muscle forces and the forces sustained during a golf swing are less than that required to cause damage to the ligaments. However, the complex motion of the golf swing, involving both substantial forces and ranges of rotational movement, demands good technique if the player is to avoid injuring their knee joint. Most knee injury in golf is likely related to joint laxity, previous injuries or arthritis, and such damage may be exacerbated by problems in technique or overuse. In addition to appropriate coaching, strategies to remedy discomfort include specific exercise programmes, external bracing, orthotics and equipment choices.

  11. Biomechanical risk factors and mechanisms of knee injury in golfers.

    Science.gov (United States)

    Marshall, Robert N; McNair, Peter J

    2013-09-01

    Knee injuries in golf comprise approximately 8% of all injuries, and are considered to result from overuse, technical faults or a combination of those factors. This review examines factors involved in injury, including the structure of the knee joint, kinematics and kinetics of the golf swing, forces sustained by knee joint structures and the potential for joint injury as well as injury prevention strategies. The golf swing generates forces and torques which tend to cause internal or external rotation of the tibia on the femur, and these are resisted by the knee ligaments and menisci. Research has shown that both maximum muscle forces and the forces sustained during a golf swing are less than that required to cause damage to the ligaments. However, the complex motion of the golf swing, involving both substantial forces and ranges of rotational movement, demands good technique if the player is to avoid injuring their knee joint. Most knee injury in golf is likely related to joint laxity, previous injuries or arthritis, and such damage may be exacerbated by problems in technique or overuse. In addition to appropriate coaching, strategies to remedy discomfort include specific exercise programmes, external bracing, orthotics and equipment choices. PMID:24245048

  12. Getting your home ready - knee or hip surgery

    Science.gov (United States)

    ... Hip joint replacement Knee arthroscopy Knee joint replacement Knee microfracture surgery Patient Instructions ACL reconstruction - discharge Hip fracture - discharge Hip or knee replacement - after - what to ...

  13. Arthritic Pain Relief through Partial Knee Replacement

    Medline Plus

    Full Text Available ... or just natural wear and tear and excessive exercise, ultimately leading to arthritis. Again, this is just ... maybe what we would have appreciated with our physical exam during the office ... to more high impact activities, what do you tell them about partial knee ...

  14. Knee Pain and the Weekend Warriors

    Medline Plus

    Full Text Available ... meniscal tears in the young and athletic-type population like this gentleman, you know, very active, obviously ... you would, of knee arthritis in the female population. So, Dr. Lavernia, you’re saying that there’s ...

  15. A purpose-built dynamometer to objectively measure static and dynamic knee torque.

    Science.gov (United States)

    Ugbolue, U C; Kaliarntas, K T; Wearing, S C; Rowe, P J

    2011-05-01

    This paper reports the development of a purpose-built knee dynamometer (PBKD) to evaluate passive range of motion (ROM) and isometric muscle strength measurements of the knee. The PBKD uses a TorqSense rotary torque transducer and objectively measures isometric knee muscle strength in a valid and reliable manner and passive resistance to motion through range. The device and all associated instrumentation underwent dynamic and static calibration to ensure consistent and accurate measurements were obtained in terms of knee joint angular position, passive torque measures, and isometric torque measures. Eleven healthy male participants performed a knee flexion and extension task designed to evaluate knee function. The validation of the PBKD entailed measuring the consistency of measurement and accuracy of measurement. Accuracy of the PBKD was determined by comparing peak isometric muscle strength measurements against a KIN-COM machine. No significant differences were observed both passively and isometrically between cycles and between trials. This device can have widespread applications within the rehabilitation and clinical environment and could be used as a functional outcome measuring tool to distinguish pathological from non-pathological knees. The presented preliminary results indicate that reliable and accurate measurements of knee ROM and muscle strength can be obtained.

  16. The influence of knee marker placement error on evaluation of gait kinematic parameters.

    Science.gov (United States)

    Szczerbik, Ewa; Kalinowska, Małgorzata

    2011-01-01

    Vicon motion system is an accurate equipment for objective gait analysis. According to clinical experience the most important source of errors in kinematics is marker misplacement. It seems that knee marker placement is especially important because of its direct influence on two body segments: thigh and shank. There is little data in the literature on how the misplacement of knee marker determines the changes of kinematic parameters. Therefore the aim of this study was to collect the kinematic data of subjects with different knee pathologies (one with knee flexion contracture, the second with knee hyperextension) while knee marker position was changed in a systematical way. They were walking with their natural, preferred speed. The data were collected using VICON460 motion system, the Helen Hayes marker set and Plug-In-Gait model. Then they were processed based on Polygon software. The results of both subjects showed the changes of kinematics, depending on the knee marker misplacement. The assessed joint ranges of angle change were: in knee, 18° in sagittal plane and 20° in frontal plane; in hip, 10° in sagittal plane and 24° in transversal plane; in ankle, 10° in sagittal plane and 25° in transversal plane. This paper presents the detailed data which could help the users of such systems to interpret the kinematic data.

  17. Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis.

    Science.gov (United States)

    Kim, Jung-Hwan; Ji, Sang-Goo; Jung, Kang-Jae; Kim, Jae-Hyung

    2016-04-01

    A 54-year-old man with poliomyelitis had been using a conventional, passive knee-ankle-foot orthosis (KAFO) with a drop ring lock knee joint for about 40 years. A stance control KAFO (SCKAFO) with an electromagnetically controlled (E-MAG) knee joint system was prescribed. To correct his gait pattern, he also underwent rehabilitation therapy, which included muscle re-education, neuromuscular electrical stimulation, strengthening exercises for the lower extremities, and balance training twice a week for about 4 months. Both before and after rehabilitation, we conducted a gait analysis and assessed the physiological cost index in energy expended during walking in a locked-knee state and while he wore a SCKAFO with E-MAG. When compared with the pre-rehabilitation data, the velocity, step length, stride length, and knee kinematic data were improved after rehabilitation. Although the SCKAFO with E-MAG system facilitated the control of knee motion during ambulation, appropriate rehabilitative therapy was also needed to achieve a normal gait pattern. PMID:27152288

  18. Traumatic knee extension deficit (the locked knee)

    DEFF Research Database (Denmark)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    . Evaluating MRI, all grade-3 meniscal lesions were considered able to cause a mechanical block as well as acute partial or total anterior cruciate ligament (ACL)-ruptures. ACL-ruptures with an old appearance were not considered able to cause locking. Assuming that arthroscopy was the gold standard......, the following results were calculated for the overall appearance of a lesion able to cause locking: Positive predictive value = 0.85, negative predictive value = 0.77, sensitivity = 0.95, specificity = 0.53. Two knees were erroneously evaluated with no mechanical locking at MRI (one bucket-handle lesion and one...

  19. Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty?

    DEFF Research Database (Denmark)

    Nielsen, Katrine Abildgaard; Thomsen, Morten Grove; Latifi Yaghin, Roshan;

    2016-01-01

    awareness) with decreasing knee awareness for decreasing tibio-femoral angles. Post-operative alignment did not significantly affect FJS. CONCLUSION: Knee awareness did not differ significantly between the "best" and the "worst" knee. Bilateral simultaneous TKA can be performed without compromising the...

  20. A kinematic assessment of knee prosthesis from fluoroscopy images

    International Nuclear Information System (INIS)

    We have developed a technique for estimation 3D motion of knee prosthesis from its 2D perspective projections. Our estimation algorithm includes some innovations such as a two-step estimation algorithm, incorporative use of a geometric articulation model and a new method to solve two silhouettes' overlapping problem. Computer model simulations and experiments results demonstrated that our algorithms give sufficient accuracy. Next, with the cooperation of medical surgeons, we assessed the algorithm's clinical performance by applying it to moving fluoroscopy images of patients who had just undergone total knee arthroplasty (TKA) recently. Our experiments were done in four steps; first we have taken the moving X-ray pictures called fluoroscopy images of the knee prosthesis at different knee motions; second, introduced the absolute positions/orientations for both components, third, introduced the relative positions/orientations between the femoral and the tibial components and finally, introduced the contact points trajectories between the femur and the tibial insert. We drew the estimation results graphically and made the computer-aided detection (CAD) model pictures of the prosthesis, thereby helping us to assess how the relative motions between the femoral and the tibial components were generated. Estimation results of the clinical applications demonstrated that our algorithm worked well as like as theoretical. (author)