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Sample records for activity knee motion

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

    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

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

    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...

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

    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 ...

  5. Factors Influencing Range of Motion after Total Knee Arthroplasty

    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...

  6. Predicted knee kinematics and kinetics during functional activities using motion capture and musculoskeletal modelling in healthy older people

    Worsley, Peter; Stokes, Maria; Taylor, Mark

    2011-01-01

    Knowledge of joint forces and moments is essential for comparisons between healthy people and those with pathological conditions, with observed changes at joints providing basis for a particular intervention. Currently the literature analysing both kinematics and kinetics at the knee has been limited to small samples, typically of young subjects or those who have undergone joint arthroplasty. In this study, we examined tibiofemoral joint (TFJ) kinematics and kinetics during gait, sit-stand-si...

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

    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...

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

    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

  9. Canonical active Brownian motion

    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...

  10. Active knee joint flexibility and sports activity

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

    1999-01-01

    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...

  11. Femoropatellar gliding movement during active stretching of the knee

    By means of motion-triggered MRT it has been possible for the first time to demonstrate movements in the patello-femoral joint by means of MRT. Patello-femoral movement was studied during active extension of the knee between 30deg flexion and complete extension. The knees of 5 normal females and 7 normal males were studied together with 2 women with recurrent lateral patellar luxation. In normal women there was an average 16deg (10 to 18deg), in men an average of 12deg (10 to 14deg) of lateralisation of the patella during complete extension of the knee. In 1 patient there was 10deg medial displacement of the patella before extension. In 2 knees with recurrent lateral subluxation there was a 20 and 24deg displacement of the patella. (orig.)

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

    Jakobsen, Thomas Linding; Christensen, Malene; Christensen, Stine Sommer; Olsen, Marie; Bandholm, Thomas

    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-teste...

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

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

    2010-01-01

    -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...... and between physiotherapists (except passive knee extension). Changes in knee joint ROM of more than 6.6 degrees and 10 degrees (except active knee flexion) and knee joint circumference of more than 1.0 cm and 1.63 cm represent a real clinical improvement (SRD) or deterioration for a single individual within...

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

    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.

  15. Clinically assessed mediolateral knee motion: impact on gait

    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....

  16. Behavioral effect of knee joint motion on body's center of mass during human quiet standing.

    Yamamoto, Akio; Sasagawa, Shun; Oba, Naoko; Nakazawa, Kimitaka

    2015-01-01

    The balance control mechanism during upright standing has often been investigated using single- or double-link inverted pendulum models, involving the ankle joint only or both the ankle and hip joints, respectively. Several studies, however, have reported that knee joint motion during quiet standing cannot be ignored. This study aimed to investigate the degree to which knee joint motion contributes to the center of mass (COM) kinematics during quiet standing. Eight healthy adults were asked to stand quietly for 30s on a force platform. Angular displacements and accelerations of the ankle, knee, and hip joints were calculated from kinematic data obtained by a motion capture system. We found that the amplitude of the angular acceleration was smallest in the ankle joint and largest in the hip joint (ankle < knee < hip). These angular accelerations were then substituted into three biomechanical models with or without the knee joint to estimate COM acceleration in the anterior-posterior direction. Although the "without-knee" models greatly overestimated the COM acceleration, the COM acceleration estimated by the "with-knee" model was similar to the actual acceleration obtained from force platform measurement. These results indicate substantial effects of knee joint motion on the COM kinematics during quiet standing. We suggest that investigations based on the multi-joint model, including the knee joint, are required to reveal the physiologically plausible balance control mechanism implemented by the central nervous system. PMID:25248799

  17. Dynamic Frequency Analyses of Lower Extremity Muscles during Sit-To-Stand Motion for the Patients with Knee Osteoarthritis.

    Masaya Anan

    Full Text Available Muscle activities during the sit-to-stand motion (STS are characterized by coordinated movements between hip extensors and knee extensors. However, previous reports regarding the STS and lower extremity muscle activities have focused on some quantitative assessment, but little qualitative research. This study aimed to examine the muscle activities of the lower extremity both quantitatively and qualitatively.Study participants included 13 patients with knee osteoarthritis (knee OA and 11 age-matched asymptomatic controls. The task was STS from a chair with a height-adjustable seat. EMG activities were acquired using surface electromyogram. The root mean square signals normalized as a percentage of maximum voluntary isometric contraction values (RMS%MVC and the mean power frequency (MPF were calculated.During STS, knee OA patients had increased RMS%MVC of the vastus medialis and raised MPF of the rectus femoris before buttocks-off.These findings suggest that STS of knee OA patients not only increased relative muscle activity of the vastus medialis, but also enlisted the rectus femoris in knee extension to improve muscle contraction force by activating more type II fibers to accomplish buttocks-off.

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

    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.

  19. Prevalence of knee instability in relation to sports activity

    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...

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

    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.

  1. Contributions of Muscles to Terminal-Swing Knee Motions Vary with Walking Speed

    Arnold, Allison S.; Schwartz, Michael H.; Thelen, Darryl G.; Scott L. Delp

    2007-01-01

    Many children with cerebral palsy walk with diminished knee extension during terminal swing, at speeds much slower than unimpaired children. Treatment of these gait abnormalities is challenging because the factors that extend the knee during normal walking, over a range of speeds, are not well understood. This study analyzed a series of three-dimensional, muscle-driven dynamic simulations to determine whether the relative contributions of individual muscles and other factors to angular motion...

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

    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

    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. Range of Motion of the Ankle According to Pushing Force, Gender and Knee Position

    Cho, Kang Hee; Lee, Hyunkeun

    2016-01-01

    Objective To investigate the difference of range of motion (ROM) of ankle according to pushing force, gender and knee position. Methods One hundred and twenty-eight healthy adults (55 men, 73 women) between the ages of 20 and 51, were included in the study. One examiner measured the passive range of motion (PROM) of ankle by Dualer IQ Inclinometers and Commander Muscle Testing. ROM of ankle dorsiflexion (DF) and plantarflexion (PF) according to change of pushing force and knee position were measured at prone position. Results There was significant correlation between ROM and pushing force, the more pushing force leads the more ROM at ankle DF and ankle PF. Knee flexion of 90° position showed low PF angle and high ankle DF angle, as compared to the at neutral position of knee joint. ROM of ankle DF for female was greater than for male, with no significant difference. ROM of ankle PF for female was greater than male regardless of the pushing force. Conclusion To our knowledge, this is the first study to assess the relationship between pushing force and ROM of ankle joint. There was significant correlation between ROM of ankle and pushing force. ROM of ankle PF for female estimated greater than male regardless of the pushing force and the number of measurement. The ROM of the ankle is measured differently according to the knee joint position. Pushing force, gender and knee joint position are required to be considered when measuring the ROM of ankle joint. PMID:27152277

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

    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

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

    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.

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

    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.``

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

    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....

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

    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. PMID:21142329

  10. Daily Spousal Influence on Physical Activity in Knee Osteoarthritis

    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

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

    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

  12. 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.

    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

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

    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...

  14. The Role of Knee Positioning and Range-of-Motion on the Closed-Stance Forehand Tennis Swing

    Steven M. Nesbit; Monika Serrano; Mike Elzinga

    2008-01-01

    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 posit...

  15. Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut

    Cronin, Baker; Johnson, Samuel T.; Chang, Eunwook; Pollard, Christine D.; Norcross, Marc F.

    2016-01-01

    Background: The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD). Hypothesis: Females with greater hip abduction and extension RTD would exhibit lesser frontal plane hip and knee motion during a single-leg jump-cutting task. Study Design: Descriptive laboratory study. Methods: Forty recreationally active females performed maximal isometric contractions and single-leg jump-cuts. From recorded torque data, hip extension and abduction RTD was calculated from torque onset to 200 ms after onset. Three-dimensional motion analysis was used to quantify frontal plane hip and knee kinematics during the movement task. For each RTD measure, jump-cut biomechanics were compared between participants in the highest (high) and lowest (low) RTD tertiles. Results: No differences in frontal plane hip and knee kinematics were identified between high and low hip abduction RTD groups. However, those in the high hip extension RTD group exhibited lower hip adduction (high, 3.8° ± 3.0°; low, 6.5° ± 3.0°; P = .019) and knee valgus (high, –2.5° ± 2.3°; low, –4.4° ± 3.2°; P = .046) displacements during the jump-cut. Conclusion: In movements such as cutting that are performed with the hip in a relatively abducted and flexed position, the ability of the gluteus medius to control hip adduction may be compromised. However, the gluteus maximus, functioning as a hip abductor, may take on a pivotal role in controlling hip adduction and knee valgus motion during these types of tasks. Clinical Relevance: Training with a specific emphasis on increasing explosive strength of the hip extensors may be a means through which to improve frontal plane hip and knee

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

    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...... when performing knee extensions using the training machine. In VL and VM the EMG-angle pattern was different between the two training modalities (significant angle by exercise interaction). When using elastic resistance, the EMG-angle pattern peaked towards full knee extension (0°), whereas angle at...... peak EMG occurred closer to knee flexion position (90°) during the machine exercise. Perceived loading (Borg CR10) was similar during knee extensions performed with elastic tubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5). CONCLUSION: Knee extensions performed with...

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

    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.

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

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

    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. PMID:27119034

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

    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 ...

  20. Definition and evaluation of testing scenarios for knee wear simulation under conditions of highly demanding daily activities.

    Schwiesau, Jens; Schilling, Carolin; Kaddick, Christian; Utzschneider, Sandra; Jansson, Volkmar; Fritz, Bernhard; Blömer, Wilhelm; Grupp, Thomas M

    2013-05-01

    The objective of our study was the definition of testing scenarios for knee wear simulation under various highly demanding daily activities of patients after total knee arthroplasty. This was mainly based on a review of published data on knee kinematics and kinetics followed by the evaluation of the accuracy and precision of a new experimental setup. We combined tibio-femoral load and kinematic data reported in the literature to develop deep squatting loading profiles for simulator input. A servo-hydraulic knee wear simulator was customised with a capability of a maximum flexion of 120°, a tibio-femoral load of 5000N, an anterior-posterior (AP) shear force of ±1000N and an internal-external (IE) rotational torque of ±50Nm to simulate highly demanding patient activities. During the evaluation of the newly configurated simulator the ability of the test machine to apply the required load and torque profiles and the flexion kinematics in a precise manner was examined by nominal-actual profile comparisons monitored periodically during subsequent knee wear simulation. For the flexion kinematics under displacement control a delayed actuator response of approximately 0.05s was inevitable due to the inertia of masses in movement of the coupled knee wear stations 1-3 during all applied activities. The axial load and IE torque is applied in an effective manner without substantial deviations between nominal and actual load and torque profiles. During the first third of the motion cycle a marked deviation between nominal and actual AP shear load profiles has to be noticed but without any expected measurable effect on the latter wear simulation due to the fact that the load values are well within the peak magnitude of the nominal load amplitude. In conclusion the described testing method will be an important tool to have more realistic knee wear simulations based on load conditions of the knee joint during activities of daily living. PMID:22922096

  1. 78 FR 38098 - Proposed Information Collection (Knee and Lower Leg Disability Benefits Questionnaire) Activity...

    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...

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

    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

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

    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...

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

    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...

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

    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

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

    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.

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

    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

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

    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.

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

    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.

  10. The effects of core muscle activation on dynamic trunk position and knee abduction moments: implications for ACL injury.

    Jamison, Steve T; McNally, Michael P; Schmitt, Laura C; Chaudhari, Ajit M W

    2013-09-01

    Anterior cruciate ligament (ACL) injury is one of the most common serious lower-extremity injuries experienced by athletes participating in field and court sports and often occurs during a sudden change in direction or pivot. Both lateral trunk positioning during cutting and peak external knee abduction moments have been associated with ACL injury risk, though it is not known how core muscle activation influences these variables. In this study, the association between core muscle pre-activation and trunk position as well as the association between core muscle pre-activation and peak knee abduction moment during an unanticipated run-to-cut maneuver were investigated in 46 uninjured individuals. Average co-contraction indices and percent differences between muscle pairs were calculated prior to initial contact for internal obliques, external obliques, and L5 extensors using surface electromyography. Outside tilt of the trunk was defined as positive when the trunk was angled away from the cutting direction. No significant associations were found between pre-activations of core muscles and outside tilt of the trunk. Greater average co-contraction index of the L5 extensors was associated with greater peak knee abduction moment (p=0.0107). Increased co-contraction of the L5 extensors before foot contact could influence peak knee abduction moment by stiffening the spine, limiting sagittal plane trunk flexion (a motion pattern previously linked to ACL injury risk) and upper body kinetic energy absorption by the core during weight acceptance. PMID:23891313

  11. Reciprocating motion of active deformable particles

    Tarama, M.; Ohta, T.

    2016-05-01

    Reciprocating motion of an active deformable particle in a homogeneous medium is studied theoretically. For generality, we employ a simple model derived from symmetry considerations for the center-of-mass velocity and elliptical and triangular deformations in two dimensions. We carry out, for the first time, a systematic investigation of the reciprocating motion of a self-propelled particle. It is clarified that spontaneous breaking of the front-rear asymmetry is essential for the reciprocating motion. Moreover, two routes are found for the formation of the reciprocating motion. One is a bifurcation from a motionless stationary state. The other is destabilisation of an oscillatory rectilinear motion.

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

    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.

  13. Femoropatellar gliding movement during active stretching of the knee. Imaging with movement-triggered MR tomography. Die femoropatellare Gleitbewegung waehrend aktiver Kniestreckung. Darstellung mit bewegungsgetriggerter MR-Tomographie

    Brossmann, J.; Muhle, C.; Melchert, U.H.; Spielmann, R.P. (Universitaet Kiel, Klinik fuer Radiologische Diagnostik (Germany)); Schroeder, C. (Universitaets-Kinderklinik Kiel, Roentgenabteilung (Germany)); Hassenpflug, J. (Orthopaedische Universitaetsklinik Kiel (Germany))

    1992-06-01

    By means of motion-triggered MRT it has been possible for the first time to demonstrate movements in the patello-femoral joint by means of MRT. Patello-femoral movement was studied during active extension of the knee between 30deg flexion and complete extension. The knees of 5 normal females and 7 normal males were studied together with 2 women with recurrent lateral patellar luxation. In normal women there was an average 16deg (10 to 18deg), in men an average of 12deg (10 to 14deg) of lateralisation of the patella during complete extension of the knee. In 1 patient there was 10deg medial displacement of the patella before extension. In 2 knees with recurrent lateral subluxation there was a 20 and 24deg displacement of the patella. (orig.).

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

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

    2016-01-01

    OBJECTIVE: To investigate associations between lower levels of muscle strength, physical performance and physical activity and the risk of knee replacement (KR) in older adults with frequent knee pain. METHOD: Participants from the Multicenter Osteoarthritis Study (MOST) with knee pain on most of...... the past 30 days at baseline were included (n=1,257; mean (SD) age of 62.2 (8.2)). We examined the association between 1) baseline peak isokinetic knee extensor strength, (60°/sec, maximum out of 4 trials), 2) best time to stand in timed chair stand (2 trials of 5 repetitions), and 3) baseline...... Physical Activity Scale for the Elderly score with incident KR between baseline and the 84-month follow-up. RESULTS: 1,252 (99.6%) participants (1,682 knees) completed the follow-up visits. 331 participants (394 knees) underwent a KR during the 84 months (229 women and 102 men). The crude analysis...

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

    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...

  16. Optimal control for the active above-knee prosthesis.

    Popović, D; Oğuztöreli, M N; Stein, R B

    1991-01-01

    Control of an active above-knee prosthesis has been simulated for a selected gait activity using a hierarchical closed-loop method. An extension of finite-state control, referred to as artificial reflex control, was adopted at the strategic level of control. At the actuator level of control an optimal tracking method, based on dynamic programming, is applied. This deals mainly with the actuator level of control, but considers the interaction of the leg dynamics and the switching effects of artificial reflex control. Optimal tracking at the actuator level of the above-knee prosthesis reduces the on-off effects of finite-state methods, such as artificial reflex control. The proposed method can also be used for the design of prosthetic elements. Specific attention is paid to the limited torque and power in the prosthetic joint actuator, which are imposed by the principle of self-containment in the artificial leg. The hierarchical structure, integrating artificial reflex control and optimal tracking, can be used in real time, as estimated from the number of computer operations required for the suggested method. PMID:2048773

  17. Comparison of the long-term effectiveness of progressive neuromuscular facilitation and continuous passive motion therapies after total knee arthroplasty.

    Alaca, Nuray; Atalay, Ayçe; Güven, Zeynep

    2015-11-01

    [Purpose] The aim of this longitudinal study was to examine the long term functional effectiveness of proprioceptive neuromuscular facilitation (PNF) after total knee arthroplasty. [Subjects and Methods] We included 30 patients and they were randomly assigned to two groups. In addition to the standard rehabilitation program the PNF group received proprioceptive neuromuscular facilitation therapy and the CPM group received continuous passive motion therapy. The outcome measures included range of motion using a goniometer, pain scores using a numeric pain rating scale, days to reach functional benchmarks, the Beck depression scale and isokinetic torque and isometric strength measurements. [Results] There were no significant differences between the two groups in terms of baseline demographic data, clinical findings and length of stay. Days to reach range of motion benchmarks were similar in the two groups. Pain at the 8th week was slightly higher in the PNF group. With the exception of walking with a walker, days to reach functional benchmarks were statistically significantly fewer in patients of the PNF group despite similar isokinetic measurements. Administration of PNF resulted in earlier functional gains in patients after total knee arthroplasty. These functional accomplishments were more pronounced in the PNF group despite it having isokinetic torque measurements similar to those of the CPM group. [Conclusion] PNF techniques can positively affect functional outcomes over the long term. PMID:26696702

  18. The mechanics of activated semitendinosus are not representative of the pathological knee joint condition of children with cerebral palsy.

    Ateş, Filiz; Temelli, Yener; Yucesoy, Can A

    2016-06-01

    Characteristic cerebral palsy effects in the knee include a restricted joint range of motion and forcefully kept joint in a flexed position. To show whether the mechanics of activated spastic semitendinosus muscle are contributing to these effects, we tested the hypothesis that the muscle's joint range of force exertion is narrow and force production capacity in flexed positions is high. The isometric semitendinosus forces of children with cerebral palsy (n=7, mean (SD)=7years (8months), GMFCS levels III-IV, 12 limbs tested) were measured intra-operatively as a function of knee angle, from flexion (120°) to full extension (0°). Peak force measured in the most flexed position was considered as the benchmark. However, peak force (mean (SD)=112.4N (54.3N)) was measured either at intermediate or even full knee extension (three limbs) indicating no narrow joint range of force exertion. Lack of high force production capacity in flexed knee positions (e.g., at 120° negligible or below 22% of the peak force) was shown except for one limb. Therefore, our hypothesis was rejected for a vast majority of the limbs. These findings and those reported for spastic gracilis agree, indicating that the patients' pathological joint condition must rely on a more complex mechanism than the mechanics of individual spastic muscles. PMID:27128957

  19. 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.

    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

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

    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...

  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

    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

    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)....

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

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Andersen, Lars L.; Bandholm, Thomas

    2016-01-01

    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 ...

  4. Strength Training to Contraction Failure Increases Voluntary Activation of the Quadriceps Muscle Shortly After Total Knee Arthroplasty

    Mikkelsen, Elin Karin; Jakobsen, Thomas Linding; Holsgaard-Larsen, Anders; Andersen, Lars Louis; Bandholm, Thomas

    2016-01-01

    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 ...

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

    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 (

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

    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 (

  7. Getting Active After Knee Replacement Might Raise Hip Fracture Risk

    ... exact reason for the increase in hip and spine fractures isn't clear, it's most likely due "to ... Osteoporosis International . "The increasing risk for hip and vertebral fracture in the 10 years after knee replacement may ...

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

    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

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

    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

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

    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.

  11. Avoidance of activity and disability in patients with osteoarthritis of the knee: the mediating role of muscle strength.

    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 physical disability in patients with osteoarthritis (OA) of the knee. METHODS: Data on avoidance of activity, observed physical disability, and muscle strength of the knee in 107 patients with knee OA we...

  12. Geometric control of active collective motion

    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...

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

    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.

  14. Motion

    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

  15. Extreme fluctuations of active Brownian motion

    Pietzonka, Patrick; Kleinbeck, Kevin; Seifert, Udo

    2016-05-01

    In active Brownian motion, an internal propulsion mechanism interacts with translational and rotational thermal noise and other internal fluctuations to produce directed motion. We derive the distribution of its extreme fluctuations and identify its universal properties using large deviation theory. The limits of slow and fast internal dynamics give rise to a kink-like and parabolic behavior of the corresponding rate functions, respectively. For dipolar Janus particles in two- and three-dimensions interacting with a field, we predict a novel symmetry akin to, but different from, the one related to entropy production. Measurements of these extreme fluctuations could thus be used to infer properties of the underlying, often hidden, network of states.

  16. Greater Hip Extension but Not Hip Abduction Explosive Strength Is Associated With Lesser Hip Adduction and Knee Valgus Motion During a Single-Leg Jump-Cut

    Cronin, Baker; Johnson, Samuel T; Chang, Eunwook; Pollard, Christine D.; Norcross, Marc F.

    2016-01-01

    Background: The relationships between hip abductor and extensor strength and frontal plane hip and knee motions that are associated with anterior cruciate ligament injury risk are equivocal. However, previous research on these relationships has evaluated relatively low-level movement tasks and peak torque rather than a time-critical strength measure such as the rate of torque development (RTD). Hypothesis: Females with greater hip abduction and extension RTD would exhibit lesser frontal plane...

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

    Vahid Mazloum; Nader Rahnama; Khalil Khayambashi

    2014-01-01

    Background: Pain and limited range of motion (ROM) are the crucial subsequent results of joint hemorrhages in individuals with bleeding disorders and hemophilia. Exercise interventions are particularly recommended in treatment of such patients. The purpose of this study was to detect the influences of conventional exercise therapy and hydrotherapy on the knee joint complications in patients with hemophilia. Methods: A total of 40 patients engaging hemophilia A were randomized into one of ...

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

    Mazloum, Vahid; Rahnama, Nader; Khayambashi, Khalil

    2014-01-01

    Background: Pain and limited range of motion (ROM) are the crucial subsequent results of joint hemorrhages in individuals with bleeding disorders and hemophilia. Exercise interventions are particularly recommended in treatment of such patients. The purpose of this study was to detect the influences of conventional exercise therapy and hydrotherapy on the knee joint complications in patients with hemophilia. Methods: A total of 40 patients engaging hemophilia A were randomized into one of thre...

  19. Effects of soft tissue artifacts on differentiating kinematic differences between natural and replaced knee joints during functional activity.

    Lin, Cheng-Chung; Lu, Tung-Wu; Lu, Hsuan-Lun; Kuo, Mei-Ying; Hsu, Horng-Chaung

    2016-05-01

    Functional performance of total knee replacement (TKR) is often assessed using skin marker-based stereophotogrammetry, which can be affected by soft tissue artifacts (STA). The current study aimed to compare the STA and their effects on the kinematics of the knee between twelve patients with TKR and twelve healthy controls during sit-to-stand, and to assess the effects of STA on the statistical between-group comparisons. Each subject performed the sit-to-stand task while motions of the skin markers and the knees were measured by a motion capture system integrated with a three-dimensional fluoroscopy technique. The bone motions measured by the three-dimensional fluoroscopy were taken as the gold standard, with respect to which the STA of the markers were obtained. The STA were found to affect the calculated segmental poses and knee kinematics between the groups differently. The STA resulted in artefactual posterior displacements of the knee joint center, with magnitudes significantly greater in TKR than controls (ptrue between-group differences in the anterior-posterior translation and internal/external rotation of knee while leading to false significant between-group differences in the abduction/adduction and proximal-distal translation. PMID:27131194

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

    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

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

    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

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

    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...

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

    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.

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

    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

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

    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

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

    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

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

    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.

  8. Why Patients Do Not Participate in Sports Activities After Total Knee Arthroplasty

    Chang, Moon Jong; Kang, Yeon Gwi; Chung, Byung June; Chang, Chong Bum; Kim, Tae Kyun

    2015-01-01

    Background It is important to identify the reasons or factors preventing patients from participating in sports activities after total knee arthroplasty (TKA) to improve patient satisfaction and general health that can be gained from regular sports activities. Purpose To determine the reasons for lack of participation in regular sports activities after TKA as perceived by patients and to identify specific factors involved. Study Design Case series; Level of evidence, 4. Methods A total of 369 patients with a follow-up longer than 1 year after TKA were included in this retrospective study. A postal survey regarding sports activities was conducted using a questionnaire gathering information such as sociodemographic data, activity levels, and sports activities after TKA. The reasons perceived by patients for not participating in sports activities were determined. Patients unable to participate in sports activities were compared with patients able to do so in terms of sociodemographic data and pre- and postoperative outcomes. Results Of the 369 patients, 88 (24%) replied that they could not participate in a sports activity. Among the perceived reasons, reasons not related to the replaced knee were more frequent than those related to the replaced knee (76% vs 24%). Symptoms related to the spine or other joints composed 25% of the total perceived reasons. The presence of medical comorbidities accounted for 16%, while symptoms in the nonreplaced knee represented 8% of the reasons. In terms of patient factors, multivariate logistic regression revealed that male sex, a floor-based (ie, non-Western) lifestyle with greater demands on knee flexion, and worse postoperative University of California at Los Angeles activity scale were associated with nonregular sports activity levels. Conclusion The perceived reasons and patient factors hindering regular sports activities after TKA were not restricted to problems with the replaced knee. Nonetheless, orthopaedic surgeons may have a

  9. On the filament motion in magnetic field of active regions

    The study of filament motion in magnetic field of active regions is fulfiled. Filament movement can possibly be presented as a drift in the crossed fields, but there exist fast movements that cannot be described as a drift. For very fast motion, with acceleration greater than that of free fall, it is sometimes necessary to assume, that the motion is carried out due to the filament's own electric current. A model, describing filament motion data, given by Mouradian M. is presented

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

    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...... 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....

  11. Runner's Knee

    ... Without Pain? Jumper's Knee Knee Injuries Anterior Cruciate Ligament (ACL) Injuries Knee Injury: Caroline's Story Medial Collateral Ligament (MCL) Injuries Sports and Exercise Safety Repetitive Stress Injuries Bursitis ...

  12. 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

    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

  13. Knee and Hip Joint Kinematics Predict Quadriceps and Hamstrings Neuromuscular Activation Patterns in Drop Jump Landings

    Malfait, Bart; Dingenen, Bart; Smeets, Annemie; Staes, Filip; Pataky, Todd; Robinson, Mark A.; Vanrenterghem, Jos; Verschueren, Sabine

    2016-01-01

    Purpose The purpose was to assess if variation in sagittal plane landing kinematics is associated with variation in neuromuscular activation patterns of the quadriceps-hamstrings muscle groups during drop vertical jumps (DVJ). Methods Fifty female athletes performed three DVJ. The relationship between peak knee and hip flexion angles and the amplitude of four EMG vectors was investigated with trajectory-level canonical correlation analyses over the entire time period of the landing phase. EMG vectors consisted of the {vastus medialis(VM),vastus lateralis(VL)}, {vastus medialis(VM),hamstring medialis(HM)}, {hamstring medialis(HM),hamstring lateralis(HL)} and the {vastus lateralis(VL),hamstring lateralis(HL)}. To estimate the contribution of each individual muscle, linear regressions were also conducted using one-dimensional statistical parametric mapping. Results The peak knee flexion angle was significantly positively associated with the amplitudes of the {VM,HM} and {HM,HL} during the preparatory and initial contact phase and with the {VL,HL} vector during the peak loading phase (p<0.05). Small peak knee flexion angles were significantly associated with higher HM amplitudes during the preparatory and initial contact phase (p<0.001). The amplitudes of the {VM,VL} and {VL,HL} were significantly positively associated with the peak hip flexion angle during the peak loading phase (p<0.05). Small peak hip flexion angles were significantly associated with higher VL amplitudes during the peak loading phase (p = 0.001). Higher external knee abduction and flexion moments were found in participants landing with less flexed knee and hip joints (p<0.001). Conclusion This study demonstrated clear associations between neuromuscular activation patterns and landing kinematics in the sagittal plane during specific parts of the landing. These findings have indicated that an erect landing pattern, characterized by less hip and knee flexion, was significantly associated with an

  14. People can understand descriptions of motion without activating visual motion brain regions

    SwethasriDravida

    2013-08-01

    Full Text Available What is the relationship between our perceptual and linguistic representations of the same event? We approached this question by asking to whether visual perception of motion and understanding linguistic depictions of motion rely on the same neural architecture. The same group of participants took part in two language tasks and one visual task. In task 1, participants made semantic similarity judgments with high (e.g. “to bounce” and low motion (e.g. “to look” words. In task 2, participants made plausibility judgments for passages describing movement (“A centaur hurled a spear…” or cognitive events (“A gentleman loved cheese…”. Task 3 was a visual motion localizer in which participants viewed animations of point-light walkers, randomly moving dots, and stationary dots changing in luminance. Based on the visual motion localizer we identified classic visual motion areas of the temporal (MT/MST and STS and parietal cortex (inferior and superior parietal lobules. We find that linguistic depictions of motion and seeing motion activate largely distinct cortical areas. Motion words did not activate any part of the visual motion system. Motion passages produced a small response in the right superior parietal lobule, but none of the temporal motion regions. These results suggest 1 as compared to words, rich language stimuli such as passages are more likely to evoke mental imagery and more likely to affect perceptual circuits and 2 effects of language on the visual system are more likely in secondary perceptual areas as compared to early sensory areas. We conclude that language and visual perception constitute distinct but interacting systems.

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

    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...

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

    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.

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

    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.

  18. Functional outcomes of uni-knee arthroplasty for medial compartment knee arthropathy in asian patients

    To Wong

    2014-12-01

    Full Text Available Background: Uni-knee arthroplasty (UKA has shown better knee kinematics and motion that may better suit the activities of daily living in Eastern countries. The purpose of this study was to evaluate the functional outcomes of UKA for medial compartment knee arthropathy in Asian patients. Methods: The study cohort consisted of 48 patients with 51 UK A knees. Only one type of prosthesis was used and all components were cemented. Postoperative management included ambulation with weight bearing, range of motion, and muscle strengthening exercises as tolerated until full recovery. The average follow-up was 52.0 ± 24.0 (range 12-92 months. The evaluation included functional assessment, the Knee Society knee and functional scores, the International Knee Document Committee (IKDC subjective and objective scores, and radiographs of the knee. Results: The overall clinical outcomes of the knee showed the functional outcome of the knee to be normal in 51%, nearly normal in 37%, abnormal in 8%, and severely abnormal in 4%. The functional activities included stair climbing in 96%, squatting in 76%, jogging in 71% and kneeling in 47%. Three-quarters of the patients were able to kneel for daily activities. Approximately 98% of the patients were satisfied with the operation. The survivorship of the prosthesis was 98% with one revision pending. Radiographic evaluations revealed the components were centered in 82% and off-centered in 18%. Osteoarthritis was 22% preoperative and 27% postoperative for the patellofemoral compartment, and 0% before and 4% after surgery for the lateral compartment. The functional outcomes showed no difference between patients with and without patellofemoral arthritis. The complications included one component malposition and one knee pain of undetermined origin. Conclusions: UKA provides excellent pain relief and restoration of knee function including kneeling, squatting, and sit-to-stand activities that perfectly fit the oriental

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

    ,

    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...

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

    Coupé, V.M.H.; Veenhof, C.; van Tulder, M W; 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 out alongside a randomised trial involving 200 patients with osteoarthritis of the hip and/or knee. Outcome measures were pain, physical functioning, self-perceived change and quality of life, asses...

  1. Effectiveness of Pain, Disease Severity and Radiological Grading on Disability of Daily Living Activities in Knee Osteoarthritis

    Deniz Evcik; Saime Ay

    2008-01-01

    Objective: In this study we planned to investigate the effects of pain, disease severity, and radiological grading on the disability of daily living activities in knee osteoarthritis (OA) patients, and to find out the determinative factors. Patients and Methods: A total of 50 knee OA patients who were admitted to the outpatient clinic of Physical Medicine and Rehabilitation clinic were included this study. The diagnosis was based on the American College of Rheumatology (ACR) criteria. Pati...

  2. Wear testing of moderate activities of daily living using in vivo measured knee joint loading.

    Jörn Reinders

    Full Text Available Resumption of daily living activities is a basic expectation for patients provided with total knee replacements. However, there is a lack of knowledge regarding the impact of different activities on the wear performance. In this study the wear performance under application of different daily activities has been analyzed. In vivo load data for walking, walking downstairs/upstairs, sitting down/standing up, and cycling (50 W & 120 W has been standardized for wear testing. Wear testing of each activity was carried out on a knee wear simulator. Additionally, ISO walking was tested for reasons of comparison. Wear was assessed gravimetrically and wear particles were analyzed. In vivo walking produced the highest overall wear rates, which were determined to be three times higher than ISO walking. Moderate wear rates were determined for walking upstairs and downstairs. Low wear rates were determined for standing up/sitting down and cycling at power levels of 50 W and 120 W. The largest wear particles were observed for cycling. Walking based on in vivo data has been shown to be the most wear-relevant activity. Highly demanding activities (stair climbing produced considerably less wear. Taking into account the expected number of loads, low-impact activities like cycling may have a greater impact on articular wear than highly demanding activities.

  3. Experimental muscle pain during a forward lunge--the effects on knee joint dynamics and electromyographic activity

    Henriksen, Marius; Alkjaer, T; Simonsen, Erik Bruun;

    2009-01-01

    OBJECTIVE: The purpose of this study was to investigate whether the knee joint dynamics during a forward lunge could be modulated by experimentally induced vastus medialis pain in healthy subjects. DESIGN: Randomised cross-over study. SETTING: Biomechanical movement laboratory. PARTICIPANTS: 20 h...... muscle pain and prevention of injuries during activities involving the knee joint.......OBJECTIVE: The purpose of this study was to investigate whether the knee joint dynamics during a forward lunge could be modulated by experimentally induced vastus medialis pain in healthy subjects. DESIGN: Randomised cross-over study. SETTING: Biomechanical movement laboratory. PARTICIPANTS: 20....... 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...

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

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

    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 (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 (10)B capture reactions. The (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 (10)B prompt gamma signals were tallied from 16 angular positions. Results demonstrate that for

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

    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

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

    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

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

    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

  8. Rehabilitation of the arthrofibrotic knee.

    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

  9. 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

    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

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

    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...

  11. Knee pain

    ... the bones of the knee Infection in the knee joint Injuries and overuse Bursitis . Inflammation from repeated pressure ... felt on the inside or outside of the knee joint. Strain or sprain . Minor injuries to the ligaments ...

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

    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.

  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

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

    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.

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

    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.

  16. The effect of active sitting on trunk motion

    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. Thompson′s quadricepsplasty for stiff knee

    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

  18. 3D motion recovery while zooming using active contours

    Martínez Marroquín, Elisa; Torras Genís, Carme

    2002-01-01

    This paper considers the problem of 3D motion recovery from a sequence of monocular images while zooming. Unlike the common trend based on point matches, the proposed method relies on the deformation of an active contour fitted to a reference object. We derive the relation between the contour deformation and the 3D motion components, assuming time-varying focal length and principal point. This relation allows us to present a method to extract the rotation matrix and the scaled translation alo...

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

    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

  20. Generic motion platform for active vision

    Weiman, Carl F. R.; Vincze, Markus

    1996-10-01

    The term 'active vision' was first used by Bajcsy at a NATO workshop in 1982 to describe an emerging field of robot vision which departed sharply from traditional paradigms of image understanding and machine vision. The new approach embeds a moving camera platform as an in-the-loop component of robotic navigation or hand-eye coordination. Visually served steering of the focus of attention supercedes the traditional functions of recognition and gaging. Custom active vision platforms soon proliferated in research laboratories in Europe and North America. In 1990 the National Science Foundation funded the design of a common platform to promote cooperation and reduce cost in active vision research. This paper describes the resulting platform. The design was driven by payload requirements for binocular motorized C-mount lenses on a platform whose performance and articulation emulate those of the human eye- head system. The result was a 4-DOF mechanisms driven by servo controlled DC brush motors. A crossbeam supports two independent worm-gear driven camera vergence mounts at speeds up to 1,000 degrees per second over a range of +/- 90 degrees from dead ahead. This crossbeam is supported by a pan-tilt mount whose horizontal axis intersects the vergence axes for translation-free camera rotation about these axes at speeds up to 500 degrees per second.

  1. Cyclops lesion of the knee.

    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.

  2. Sex Differences in Valgus Knee Angle During a Single-Leg Drop Jump

    Russell, Kyla A; Palmieri, Riann M.; Zinder, Steven M.; Ingersoll, Christopher D.

    2006-01-01

    Context: Sex differences in lower extremity landing mechanics and muscle activation have been identified as potential causative factors leading to the increased incidence of anterior cruciate ligament injuries in female athletes. Valgus knee alignment places greater strain on the anterior cruciate ligament than a more neutral alignment. Gluteus medius (GM) activation may stabilize the leg and pelvis during landing, limiting valgus knee motion and potentially preventing anterior cruciate ligam...

  3. Tracer motion in an active dumbbell fluid

    Suma, Antonio; Cugliandolo, Leticia F.; Gonnella, Giuseppe

    2016-05-01

    The diffusion properties of spherical tracers coupled through a repulsive potential to a system of active dumbbells are analyzed. We model the dumbbells’ dynamics with Langevin equations and the activity with a self-propulsive force of constant magnitude directed along the main axis of the molecules. Two types of tracers are considered. Thermal tracers are coupled to the same bath as the dumbbells while athermal tracers are not; both interact repulsively with the dumbbells. We focus our attention on the intruders’ mean square displacement and how it compares to the one of the dumbbells. We show that the dynamics of thermal intruders, with mass similar to the one of the dumbbells, display the typical four time-lag regimes of the dumbbells’ mean square displacement. The thermal tracers’ late-time diffusion coefficient depends on their mass very weakly and it is close to the one of the dumbbells at low Péclet only. Athermal tracers only have ballistic and late-time diffusive regimes. The late time diffusion coefficients of athermal tracers and dumbbells have similar values at high Péclet number when their masses are of the same order, while at low Péclet number this coefficient gets close to the one of the dumbbells only when the tracers are several order of magnitude heavier than the dumbbells. We propose a generalization of the Enskog law for dilute hard disks, that describes the athermal tracers’ mean square displacement in the form of a scaling law in terms of their mass.

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

    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...

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

    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 ...

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

    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

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

    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

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

    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

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

    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...

  10. 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

    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.

  11. In Vivo Healthy Knee Kinematics during Dynamic Full Flexion

    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.

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

    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.

  13. Statistics of Superluminal Motion in Active Galactic Nuclei

    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.

  14. 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

    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.

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

    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...

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

    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.)

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

    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

  18. Knee Injuries

    ... 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. ...

  19. Knee Problems

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

    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...

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

    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

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

    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.

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

    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 ...

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

    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. The usability and preliminary effectiveness of a web-based physical activity intervention in patients with knee and/or hip osteoarthritis

    Bossen, D.; Veenhof, C.; Dekker, J.; Bakker, D.

    2013-01-01

    Background A large proportion of patients with knee and/or hip osteoarthritis (OA) do not meet the recommended levels of physical activity (PA). Therefore, we developed a web-based intervention that provides a tailored PA program for patients with knee and/or hip OA, entitled Join2move. The intervention incorporates core principles of the behaviour graded activity theory (BGA). The aim of this study was to investigate the preliminary effectiveness, feasibility and acceptability of Join2move i...

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

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

    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...

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

    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.

  9. Validation of an electrogoniometry system as a measure of knee kinematics during activities of daily living

    Urwin, Samuel; Kader, Deiary; Caplan, Nick; St Clair Gibson, Alan; Stewart, Su

    2013-01-01

    Purpose: The increasing use of electrogoniometry (ELG) in clinical research requires the validation of different instrumentation. The purpose of this investigation was to examine the concurrent validity of an ELG system during activities of daily living. Methods: Ten asymptomatic participants gave informed consent to participate. A Biometrics SG150 electrogoniometer was directly compared to a 12 camera three dimensional motion analysis system during walking, stair ascent, stair descent, s...

  10. Collective motion in an active suspension of Escherichia coli bacteria

    We investigate experimentally the emergence of collective motion in the bulk of an active suspension of Escherichia coli bacteria. When increasing the concentration from a dilute to a semi-dilute regime, we observe a continuous crossover from a dynamical cluster regime to a regime of ‘bio-turbulence’ convection patterns. We measure a length scale characterizing the collective motion as a function of the bacteria concentration. For bacteria fully supplied with oxygen, the increase of the correlation length is almost linear with concentration and at the largest concentrations tested, the correlation length could be as large as 24 bacterial body sizes (or 7–8 when including the flagella bundle). In contrast, under conditions of oxygen shortage the correlation length saturates at a value of around 7 body lengths. (paper)

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

    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.

  12. Estimation of the knee joint angle from surface electromyographic signals for active control of leg prostheses

    The surface electromyographic (SEMG) signal is very convenient for prosthesis control because it is non-invasively acquired and intrinsically related to the user's intention. This work presents a feature extraction and pattern classification algorithm for estimation of the intended knee joint angle from SEMG signals acquired using two sets of electrodes placed on the upper leg. The proposed algorithm uses a combination of time-domain and frequency-domain approaches for feature extraction (signal amplitude histogram and auto-regressive coefficients, respectively), a self-organizing map for feature projection and a Levenberg–Marquardt multi-layer perceptron neural network for pattern classification. The new algorithm was quantitatively compared with the method proposed by Wang et al (2006 Med. Biol. Eng. Comput. 44 865–72), which uses wavelet packet feature extraction, principal component analysis and a multi-layer perceptron neural classifier. The proposed method provided lower error-to-signal percentage and peak error amplitudes, higher correlation and fewer error events. The algorithm presented in this work may be useful as part of a myoelectric controller for active leg prostheses designed for transfemoral amputees

  13. Alterations in lower limb multimuscle activation patterns during stair climbing in female total knee arthroplasty patients.

    Kuntze, G; von Tscharner, V; Hutchison, C; Ronsky, J L

    2015-11-01

    Total knee arthroplasty (TKA) patients commonly experience neuromuscular adaptations that may affect stair climbing competence. This study identified multimuscle pattern (MMP) changes in postoperative female TKA patients during stair climbing with a support vector machine (SVM). It was hypothesized that TKA patients adopt temporal and spectral muscle activation characteristics indicative of muscle atrophy and cocontraction strategies. Nineteen female subjects [10 unilateral sex-specific TKAs, 62.2 ± 8.6 yr, body mass index (BMI) 28.2 ± 5.4 kg/m(2); 9 healthy control subjects, 61.4 ± 7.4 yr, BMI 25.6 ± 2.4 kg/m(2)] were recruited. Surface electromyograms (EMGs) were obtained for seven lower limb muscles of the affected limb of TKA subjects and a randomly assigned limb for control subjects during stair climbing. Stance phase (±30%) EMG data were wavelet transformed and normalized to total power. Data across all muscles were combined to form MMPs and analyzed with a SVM. Statistical analysis was performed with binomial tests, independent group t-tests, or independent group Mann-Whitney U-tests in SPSS (P tool for clinical neuromuscular function assessment and rehabilitation monitoring. PMID:26354313

  14. Photothermally activated motion and ignition using aluminum nanoparticles

    Abboud, Jacques E.; Chong Xinyuan; Zhang Mingjun; Zhang Zhili [Mechanical, Aerospace and Biomedical Engineering Department, University of Tennessee, Knoxville, Tennessee 37996 (United States); Jiang Naibo; Roy, Sukesh [Spectral Energies, LLC, 5100 Springfield Street, Suite 301, Dayton, Ohio 45431 (United States); Gord, James R. [Air Force Research Laboratory, Propulsion Directorate, Wright-Patterson Air Force Base, Ohio 45433 (United States)

    2013-01-14

    The aluminum nanoparticles (Al NPs) are demonstrated to serve as active photothermal media, to enhance and control local photothermal energy deposition via the photothermal effect activated by localized surface plasmon resonance (LSPR) and amplified by Al NPs oxidation. The activation source is a 2-AA-battery-powered xenon flash lamp. The extent of the photothermally activated movement of Al NPs can be {approx}6 mm. Ignition delay can be {approx}0.1 ms. Both scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements of motion-only and after-ignition products confirm significant Al oxidation occurs through sintering and bursting after the flash exposure. Simulations suggest local heat generation is enhanced by LSPR. The positive-feedback effects from the local heat generation amplified by Al oxidation produce a large increase in local temperature and pressure, which enhances movement and accelerates ignition.

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

    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...

  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

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

    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. PMID:26644651

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

    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

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

    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

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

    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.

  1. 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

    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

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

    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

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

    Rathleff, Michael S.; Samani, Afshin; Olesen, Jens L.; Roos, Ewa M.; Rasmussen, Sten; Madeleine, Pascal

    2016-01-01

    random subsample of 57 female adolescents was included and tested at baseline and after 3months. Neuromuscular control of the knee was quantified as the complexity of surface electromyography of the vastus lateralis and vastus medialis during stair descent. Secondary outcomes were complexity of knee...... during stair descent than those receiving patient education alone. This suggest that exercise therapy has an effect not only on self-reported outcome measures but also on objective measures of thigh muscle function in female adolescents with patellofemoral pain....

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

    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.

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

    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.

  6. Knee Pain and the Weekend Warriors

    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 ...

  7. Overuse Knee Injuries in Athletes

    Miroslav Kezunović

    2013-01-01

    According to many statistics over 55% of all sports-related injuries are incurred in the knee joint (active sportsmen and recreationists). The statistics definitely differ, depending on type of sport and specific movements habitually performed in a particular sport. Therefore, in addition to acute knee injuries overuse syndromes are common in the knee area also due to specificities of patellofemoral joint just because specific diseases like „jumper's knee“ and „runner's knee“ are related to c...

  8. Knee pain

    ... 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 ...

  9. A case-control study to investigate the relation between low and moderate levels of physical activity and osteoarthritis of the knee using data collected as part of the Allied Dunbar National Fitness Survey

    Sutton, A; Muir, K; Mockett, S; Fentem, P

    2001-01-01

    BACKGROUND—Physical activity is being recommended as an intervention for seemingly almost universal improvements to health. A potential concern with this recommendation for increased exercise is that some believe increased levels of activity may lead to increased incidence of osteoarthritis of the knee (knee OA), as a result of accelerated "wear and tear" of the major joints.
OBJECTIVE—To investigate the hypothesis that the occurrence of knee OA may be related to the duration of participation...

  10. Unwinding motion of a twisted active-region filament

    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...

  11. Unwinding motion of a twisted active region filament

    Yan, X. L.; Xue, Z. K.; Kong, D. F. [Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011 (China); Liu, J. H. [Department of Physics, Shijiazhuang University, Shijiazhuang 050035 (China); Xu, C. L. [Yunnan Normal University, Kunming 650092 (China)

    2014-12-10

    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 2010 June 22. 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 consisted of twisted magnetic field lines. The total twist of the filament is at least 5π obtained by using a 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 magnetic helicity injection before and during the filament eruption. It is confirmed that magnetic helicity can be transferred from the photosphere to the filament. Using the extrapolated potential fields, the average decay index of the background magnetic fields over the filament is 0.91. Consequently, these findings imply that the mechanism of solar filament eruption could be due to the kink instability and magnetic helicity accumulation.

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

    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...

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

    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

  14. Rough terrain motion planning for actively reconfigurable mobile robots

    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

  15. Rough terrain motion planning for actively reconfigurable mobile robots

    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

  16. Nordic Walking does not reduce the loading of the knee joint

    Hansen, L; Henriksen, Michael; Larsen, P;

    2008-01-01

    The use of Nordic Walking (NW) as a rehabilitation modality has increased considerably. NW (walking with poles) is advocated as a healthy physical activity that reduces the load on the knees. Few studies using the techniques of NW exist, and the findings are contradictory. The aim of this study was...... to investigate whether NW reduces the loadings upon the knee joint compared with walking without poles (NP). Seven experienced female NW instructors volunteered. Three-dimensional gait analyses were performed. Internal flexor and extensor joint moments were calculated using an inverse dynamics...... approach and the knee joint compressive forces were calculated. No differences in compression or shear forces between NW and NP were found. The peak knee flexion angles were larger during NW (-32.5+/-6.0 degrees) compared with NP (-28.2+/-4.2 degrees). The hip range of motion (ROM) was significantly...

  17. Arthritic Pain Relief through Partial Knee Replacement

    Full Text Available ... the knee has become more deformed, there's more limited range of motion. And when somebody has damaged ... replacement in general, right? Yeah, that's right on, Bill. So the kneecap, you will see, is just ...

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

    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.

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

    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....../110 patients correlations with performance-based tests (Stair Climbing Test , Timed Up and Go test, 30 second Chair Stand Test ) were calculated. Results 17 basic daily activities were chosen for the AAQ. Video animations were made showing a person performing each activity with 3 to 5 different levels of......, and to preliminary assess its reliability and validity. We hypothesize that the AAQ correlates highly with performance-based tests, and moderately with self-reports. Methods Item selection was based on 1) the pilot AAQ; 2) pre-specified conditions; 3) the International Classification of Functioning...

  20. Motion verb sentences activate left posterior middle temporal cortex despite static context

    Wallentin, M; Ellegaard Lund, Torben; Østergaard, Svend; Østergaard, Leif; Roepstorff, A

    2005-01-01

    . 'Fictive motion' sentences are sentences in which an inanimate subject noun, semantically incapable of self movement, is coupled with a motion verb, yielding an apparent semantic contradiction (e.g. 'The path comes into the garden.'). However, this context yields no less activation in the left posterior...... middle temporal region than sentences in which the motion can be applied to the subject noun. We speculate that the left posterior middle temporal region activity in fictive motion sentences reflects the fact that the hearer applies motion to the depicted scenario by scanning it egocentrically...

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

    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

  2. Activity-based exploitation of Full Motion Video (FMV)

    Kant, Shashi

    2012-06-01

    Video has been a game-changer in how US forces are able to find, track and defeat its adversaries. With millions of minutes of video being generated from an increasing number of sensor platforms, the DOD has stated that the rapid increase in video is overwhelming their analysts. The manpower required to view and garner useable information from the flood of video is unaffordable, especially in light of current fiscal restraints. "Search" within full-motion video has traditionally relied on human tagging of content, and video metadata, to provision filtering and locate segments of interest, in the context of analyst query. Our approach utilizes a novel machine-vision based approach to index FMV, using object recognition & tracking, events and activities detection. This approach enables FMV exploitation in real-time, as well as a forensic look-back within archives. This approach can help get the most information out of video sensor collection, help focus the attention of overburdened analysts form connections in activity over time and conserve national fiscal resources in exploiting FMV.

  3. Severe Heterotopic Ossification following Total Knee Replacement

    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. Knee arthroscopy

    ... remove it. Torn or damaged anterior cruciate ligament (ACL) or posterior cruciate ligament (PCL) Torn or damaged ... in the knee Blood clot in the leg Injury to a blood vessel or nerve Infection in ...

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

    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. Knee Injuries and Disorders

    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 ...

  7. Anti-inflammatory activity of silymarin in patients with knee osteoarthritis

    Objective was to evaluate the anti-inflammatory effect of Silymarin in patients with knee osteoarthritis (OA) in comparison with piroxicam and meloxicam. A double-blind clinical trial was performed at the Department of Rheumatology, Baghdad Teaching Hospital, Iraq during the period from October 2004 to September 2005, in which 220 patients (79 males and 141 females) with painful knee osteoarthritis were randomized into 5 groups, treated with either silymarin (300mg/day), piroxicam (20mg/day), meloxicam (15mg) or a combination of silymarin with piroxicam or meloxicam. Serum levels of interleukin-1 alpha, interleukin-8 and the complement proteins C3 and C4 were assessed at zero time and after 8 weeks. Silymarin reduces significantly serum levels of IL-1 alpha and IL-8, C3 and C4 after 8 weeks compared to the pre-treatment levels, while IL-8 decreased significantly, compared to pre-treatment value. Meloxicam elevates serum levels of IL-1 alpha significantly, IL-8 did not significantly change compared to the pre-treatment value. Piroxicam or meloxicam produced slight, non-significant increase in serum levels of complement proteins after the 8-week treatment period. Adjunct use of silymarin with piroxicam results in significant reduction in both cytokines (IL-1 alpha and IL-8) and serum levels of C3 and C4. However, its adjunct use with, meloxicam did not reveal any significant changes in this respect. Silymarin reduces the elevated levels of interleukins and complement proteins, when used alone, or in combination with NSAIDs for treatment of knee OA. (author)

  8. Weight Status and Differences in Mobility Performance, Pain Symptoms, and Physical Activity in Older, Knee Osteoarthritis Patients

    Matthew J. Garver

    2014-01-01

    Full Text Available Knee osteoarthritis (OA is a leading cause of functional disability among American adults. Obesity is a strong independent risk factor for OA. While research emphasizes the role of obesity in the OA-physical function relationship, the extent to which weight status impacts salient physical, health, and pain measures in older, knee OA patients is not well delineated. The primary aim of this study was to assess differences in mobility performance (stair climb and 400-meter walk, mobility-related self-efficacy, pain symptoms (WOMAC, and measures of accelerometer-determined physical activity (PA as a function of weight status. Analysis of covariance was conducted to examine differences on the dependent variables. Obese class III patients were outperformed by their counterparts on nearly every measure of mobility, mobility-related self-efficacy, and the assessment of pain symptoms. These outcomes did not differ among other weight comparisons. Normal weight subjects outperformed classes I, II, and III counterparts on most measures of PA (engagement in moderate or greater PA and total weekly steps. Additionally, overweight participants outperformed obese class II participants and obese class I participants outperformed obese classes II and III participants on total weekly steps. Collectively, these findings underscore the meaningful differences observed in relevant OA outcomes as a function of increasing levels of body weight.

  9. The Clinical Effect of Platelet Rich Plasma Prepared Through Different Activation Methods on Patients with Knee Osteoarthritis

    Nevres Aydogan

    2014-12-01

    Full Text Available Aim: Intra-articular application of platelet rich plasma (PRP can be an alternative treatment method for knee osteoarthritis. The objective of this study was to compare the activation methods of platelet rich plasma before intra-articular application. Material and Method: A total 51 patients (76 knees was randomly selected into two groups. In group 1, activation of PRP was managed by adding calcium chloride (CaCl. In group 2, activation of PRP was managed by keeping the solution at -70° degrees for 24 hours after preparation and immersed in water at 37oC for a period of 5 minutes for complete dissolution. Then PRP was applied. The patients were assessed with VAS and WOMAC pain scores both baseline and after 2nd, 6th and 12th months of the treatment. Results: VAS and WOMAC pain scores were significantly higher at baseline compared to the results obtained at the 2nd, 6th and 12th months (p=0.06. Following 2nd, 6th and 12th months a gradual downward tendency was seen in both scores, even though no significant difference was found between the groups after 2nd, 6th and 12th months. Discussion: Patients received some clinical benefits from both activation methods. There is no significant difference between activating PRP by CaCl or -70°C which compared in terms of clinical benefits. Therefore, blood storage at -70ºC may be preferred primary due to no need for additional material such as CaCl.

  10. Multiple Ligament Knee Injury: Complications

    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 ...

  11. 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

    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

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

    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

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

    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

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

    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

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

    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

  16. Active Brownian motion of an asymmetric rigid particle

    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.

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

    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.)

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

    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.)

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

    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

  20. The Cruciate Ligaments in Total Knee Arthroplasty.

    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

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

    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

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

    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

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

    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.

  4. Total knee arthroplasty for severe valgus knee deformity

    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

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

    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.

  6. 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

    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.

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

    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...

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

    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.

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

    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

  10. Knee pain (image)

    ... 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. Anterior knee pain

    Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... or playing soccer). You have flat feet. Anterior knee pain is more ... skiers, bicyclists, and soccer players who exercise often ...

  12. Knee arthroscopy - discharge

    ... 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: ...

  13. Knee microfracture surgery

    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 ...

  14. The effect of prosthetic ankle energy storage and return properties on muscle activity in below-knee amputee walking.

    Ventura, Jessica D; Klute, Glenn K; Neptune, Richard R

    2011-02-01

    In an effort to improve amputee gait, energy storage and return (ESAR) prosthetic feet have been developed to provide enhanced function by storing and returning mechanical energy through elastic structures. However, the effect of ESAR feet on muscle activity in amputee walking is not well understood. Previous studies have analyzed commercial prosthetic feet with a wide range of material properties and geometries, making it difficult to associate specific ESAR properties with changes in muscle activity. In contrast, prosthetic ankles offer a systematic way to manipulate ESAR properties while keeping the prosthetic heel and keel geometry intact. In the present study, ESAR ankles were added to a Seattle Lightfoot2 to carefully control the energy storage and return by altering the ankle stiffness and orientation in order to identify its effect on lower extremity muscle activity during below-knee amputee walking. A total of five foot conditions were analyzed: solid ankle (SA), stiff forward-facing ankle (FA), compliant FA, stiff reverse-facing ankle (RA) and compliant RA. The ESAR ankles decreased the activity of muscles that contribute to body forward propulsion and increased the activity of muscles that provide body support. The compliant ankles generally caused a greater change in muscle activity than the stiff ankles, but without a corresponding increase in energy return. Ankle orientation also had an effect, with RA generally causing a lower change in muscle activity than FA. These results highlight the influence of ESAR stiffness on muscle activity and the importance of prescribing appropriate prosthetic foot stiffness to improve rehabilitation outcomes. PMID:21145747

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

    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

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

    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 t...

  17. POST TRAUMATIC KNEE FRACTURE ( X-RAY

    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.

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

    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.

  19. Basic biomechanic principles of knee instability.

    Zlotnicki, Jason P; Naendrup, Jan-Hendrik; Ferrer, Gerald A; Debski, Richard E

    2016-06-01

    Motion at the knee joint is a complex mechanical phenomenon. Stability is provided by a combination of static and dynamic structures that work in concert to prevent excessive movement or instability that is inherent in various knee injuries. The anterior cruciate ligament (ACL) is a main stabilizer of the knee, providing both translational and rotatory constraint. Despite the high volume of research directed at native ACL function, pathogenesis and surgical reconstruction of this structure, a gold standard for objective quantification of injury and subsequent repair, has not been demonstrated. Furthermore, recent studies have suggested that novel anatomic structures may play a significant role in knee stability. The use of biomechanical principles and testing techniques provides essential objective/quantitative information on the function of bone, ligaments, joint capsule, and other contributing soft tissues in response to various loading conditions. This review discusses the principles of biomechanics in relation to knee stability, with a focus on the objective quantification of knee stability, the individual contributions of specific knee structures to stability, and the most recent technological advances in the biomechanical evaluation of the knee joint. PMID:27007474

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

    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

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

    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 ...

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

    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...

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

    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

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

    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. Severe Heterotopic Ossification following Total Knee Replacement

    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.

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

    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.

  7. COMPARISON OF EMG ACTIVITIES OF KNEE EXTENSOR MUSCLES BETWEEN SOCCER PLAYERS AND SPRINTERS DURING COUNTERMOVEMENT JUMP PERFORMANCE

    Hasan Birol YALÇIN

    2011-12-01

    Full Text Available Aim: The purpose of this study was to compare electromyogram (EMG activities of knee extensor muscles (vastus lateralis and vastus medialis between soccer players and sprinters during countermovement jump (CMJ performance. Subjects: Fifty three subjects (Thirty two sprinters, ( age: 21,91 ± 1,55 yr; body weight: 67,29 ± 8,11 kg; height: 176,81 ± 5,87 cm and twenty one soccer players, ( age: 23,.33 ± 1,77yr; body weight: 69,50 ± 7,06kg; height: 174,33 ± 5,65cm volunteered to participate in this study. Methods: After the standard 5 minutes warm-up period, EMG signals of vastus lateralis (VL and vastus medialis (VM were recorded while subjects were performed maximal performance of CMJ. EMG signals were quantified using the root mean square (RMS value. CMJ test protocol was used to determine the jump performance (jumping height and peak power. Independent t-test was used to determine differences between sprinters and soccer players regarding to jumping height, peak power (PP and RMS values of VL and VM. Results: The results of the study indicated that the RMS values of sprinters taken from VL (t=3,318; p

  8. 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

    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

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

    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...

  10. Classification Accuracies of Physical Activities Using Smartphone Motion Sensors

    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...

  11. Unified theory of dislocation motion including thermal activation and inertial effects

    Transition-state rate theory has generally been used to explain the temperature dependence of the flow stress of a crystal. However, the existence of a change in the flow stress during the superconducting transition indicates the presence of inertial effects in which dislocations overcome obstacles mechanically rather than thermally. It is shown here that the thermally activated and the inertial overcoming of obstacles are not unrelated but can both be derived from principles of stochastic motion. This leads to a theory of dislocation motion that includes both thermal activation and inertial effects. It is also shown that a distribution of activation energies must be considered to account for the experimental data

  12. A Prospective, Longitudinal Study of Patient Activity Levels Following Total Knee Arthroplasty Stratified by Demographic and Comorbid Factors.

    Issa, Kimona; Jauregui, Julio J; Given, Kristin; Harwin, Steven F; Mont, Michael A

    2015-08-01

    With the marked increase in the annual number of total knee arthroplasties (TKAs) in the United States, there has been an increased interest in evaluating patient-reported outcomes. The purpose of this study was to prospectively and longitudinally evaluate temporal trends in patient activity levels following TKA and to identify potential demographic and comorbid factors that may affect these outcomes. This prospective study evaluated 281 patients, including 108 men and 173 women, who had a mean age of 66 years (39-80 years) and underwent primary TKA. All patients were followed for a minimum of 2 years. Medical comorbidities were recorded preoperatively and activity scores were evaluated at each follow-up visit. The effects of different patient demographics and systemic comorbidities on activity outcomes were further analyzed using multivariate regression analysis. Compared with preoperative levels, the activity score was observed to initially significantly decrease at 6 weeks postoperatively to below preoperative levels (9.2 vs. 8.1 points). By 3 months, scores were above preoperative levels (10.3 points), but below peak levels. A significant peak in the activity score was observed at 2-year follow-up after which there were no significant differences in scores at 5 years (11.49 vs. 11.47 points). In evaluating patient demographics and comorbidities, significant negative impact of older age, tobacco use, history of cancer, cardiovascular disease, lymphatic disease, and renal disease can be seen on activity levels. Activity scores following TKA follow a temporal trend in which scores initially drop below preoperative levels after surgery, but recover and reach a peak at 2 years postoperatively. This peak was maintained at 5-year follow-up. Surgeons should counsel their patients that they will not perceive the full benefit of a TKA until 1 to 2 years after surgery, in addition, patients may actually perceive their progress to decrease initially. Also, their

  13. Visuotactile motion congruence enhances gamma-band activity in visual and somatosensory cortices.

    Krebber, Martin; Harwood, James; Spitzer, Bernhard; Keil, Julian; Senkowski, Daniel

    2015-08-15

    When touching and viewing a moving surface our visual and somatosensory systems receive congruent spatiotemporal input. Behavioral studies have shown that motion congruence facilitates interplay between visual and tactile stimuli, but the neural mechanisms underlying this interplay are not well understood. Neural oscillations play a role in motion processing and multisensory integration. They may also be crucial for visuotactile motion processing. In this electroencephalography study, we applied linear beamforming to examine the impact of visuotactile motion congruence on beta and gamma band activity (GBA) in visual and somatosensory cortices. Visual and tactile inputs comprised of gratings that moved either in the same or different directions. Participants performed a target detection task that was unrelated to motion congruence. While there were no effects in the beta band (13-21Hz), the power of GBA (50-80Hz) in visual and somatosensory cortices was larger for congruent compared with incongruent motion stimuli. This suggests enhanced bottom-up multisensory processing when visual and tactile gratings moved in the same direction. Supporting its behavioral relevance, GBA was correlated with shorter reaction times in the target detection task. We conclude that motion congruence plays an important role for the integrative processing of visuotactile stimuli in sensory cortices, as reflected by oscillatory responses in the gamma band. PMID:26026813

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

    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

  15. Relations between the solar inertial motion, solar activity and geomagnetic index aa since the year 1844

    Charvátová, Ivanka; Střeštík, Jaroslav

    2007-01-01

    Roč. 40, - (2007), s. 1026-1031. ISSN 0273-1177 R&D Projects: GA AV ČR(CZ) IAA300120608 Institutional research plan: CEZ:AV0Z30120515 Keywords : solar motion * solar activity * geomagnetic activity Subject RIV: DE - Earth Magnetism, Geodesy, Geography Impact factor: 0.774, year: 2007

  16. Overload syndromes of the knee in adolescents: Sonographic findings

    Draghi, F.; Danesino, G.M.; Coscia, D.; Precerutti, M.; Pagani, C.

    2008-01-01

    Overload syndromes are caused by repetitive microtrauma, and the knee joint is most frequently affected in adolescents. The reason for this is that the knee joint is engaged in almost all sports activities. Pathologies related to the anterior aspect of the knee are: femoropatellar pain, jumper's knee syndromes, Osgood–Schlatter disease, Sinding-Larsen–Johansson syndrome and patellar stress fractures; to the medial aspect: semimembranous tendon enthesopathy and pes anserinus bursitis; to the l...

  17. Knee Pain and the Weekend Warriors

    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 ...

  18. Knee arthroplasty: are patients' expectations fulfilled?

    Nilsdotter, Anna K; Toksvig-Larsen, Sören; Roos, Ewa

    2009-01-01

    to pain and physical function after knee arthroplasty. PATIENTS AND METHODS: 102 patients (39 men) with knee osteoarthritis and who were assigned for TKR (mean age 71 (51-86) years) were investigated with KOOS, SF-36, and additional questions concerning physical activity level, expectations...

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

    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'.

  20. Relationship between hip strength and frontal plane posture of the knee during a forward lunge

    Thijs, Youri; Van Tiggelen, Damien; Willems, Tine; De Clercq, Dirk; Witvrouw, Erik

    2007-01-01

    Objective: Excessive frontal plane knee movement during forward lunge movements might be associated with the occurrence of knee injuries in tennis. Here, we attempt to determine whether hip muscle strength is related to the frontal plane motion of the knee during a functional lunge movement. Design: A correlational study. Participants: A total of 84 healthy subjects (76 men, 8 women), with no history of knee or lower leg complaints. Interventions: Muscle strength of six hip muscle gr...

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

    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.

  2. Indirect wrist MR arthrography: the effects of passive motion versus active exercise

    Purpose. In the wrist, to determine whether passive motion or active exercise yields a better indirect MR arthrographic effect following intravenous gadolinium administration.Design and patients. Twenty-six consecutive patients were studied by indirect wrist MR arthrography. In half active exercise and in half passive motion was performed. Four regions of interest were studied including the distal radioulnar joint, the radiocarpal joint, the midcarpal joint, and the triangular fibrocartilage. Ranges and means of signal intensity were calculated. Surgical follow-up was performed in 22 patients.Results. The joint fluid intensity was greatest in the distal radioulnar joint. Fluid signal intensity was greater and more consistent in the passive motion group although the results did not achieve statistical significance. Imaging accuracy appeared similar in the two groups and was excellent for the triangular fibrocartilage (100%) and scapholunate ligaments (96%).Conclusion. Active exercise and passive motion yield similar degrees of wrist arthrographic effect, but the effect of passive motion is somewhat more consistent. Preliminary data show good accuracy for internal derangements. (orig.)

  3. Multiple-ligament injured knee

    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

  4. Knees Lifted High

    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.

  5. Spontaneous chiral symmetry breaking in collective active motion

    Breier, Rebekka E.; Selinger, Robin L. B.; Ciccotti, Giovanni; Herminghaus, Stephan; Mazza, Marco G.

    2016-02-01

    Chiral symmetry breaking is ubiquitous in biological systems, from DNA to bacterial suspensions. A key unresolved problem is how chiral structures may spontaneously emerge from achiral interactions. We study a simple model of active swimmers in three dimensions that effectively incorporates hydrodynamic interactions. We perform large-scale molecular dynamics simulations (up to 106 particles) and find long-lived metastable collective states that exhibit chiral organization although the interactions are achiral. We elucidate under which conditions these chiral states will emerge and grow to large scales. To explore the complex phase space available to the system, we perform nonequilibrium quenches on a one-dimensional Lebwohl-Lasher model with periodic boundary conditions to study the likelihood of formation of chiral structures.

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

    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.

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

    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 ...

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

    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...

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

    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

  10. 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

    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

  11. Functional knee assessment with advanced imaging.

    Amano, Keiko; Li, Qi; Ma, C Benjamin

    2016-06-01

    The purpose of anterior cruciate ligament (ACL) reconstruction is to restore the native stability of the knee joint and to prevent further injury to meniscus and cartilage, yet studies have suggested that joint laxity remains prevalent in varying degrees after ACL reconstruction. Imaging can provide measurements of translational and rotational motions of the tibiofemoral joint that may be too small to detect in routine physical examinations. Various imaging modalities, including fluoroscopy, computed tomography (CT), and magnetic resonance imaging (MRI), have emerged as powerful methods in measuring the minute details involved in joint biomechanics. While each technique has its own strengths and limitations, they have all enhanced our understanding of the knee joint under various stresses and movements. Acquiring the knowledge of the complex and dynamic motions of the knee after surgery would help lead to improved surgical techniques and better patient outcomes. PMID:27052009

  12. Modeling of the condyle elements within a biomechanical knee model

    Ribeiro, Ana; Rasmussen, John; Flores, Paulo;

    2012-01-01

    condyle contact in the knee will lead to reproduction of the complex combination of flexion/extension, abduction/adduction, and tibial rotation observed in the real knee. The model is composed by two anatomic segments, the tibia and the femur, whose characteristics are functions of the geometric and...... explanation for this fact is the elastic component of the secondary motions created by the combination of joint forces and soft tissue deformations. The proposed knee model is, therefore, used to investigate whether this observed behavior can be explained by reasonable elastic deformations of the points......The development of a computational multibody knee model able to capture some of the fundamental properties of the human knee articulation is presented. This desideratum is reached by including the kinetics of the real knee articulation. The research question is whether an accurate modeling of the...

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

    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. PMID:22158094

  14. Radiological imaging of osteoarthritis of the knee

    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.)

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

    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)

  16. Evidence of left-lateral active motion at the North America-Caribbean plate boundary

    Leroy, S. D.; Ellouz, N.; Corbeau, J.; Rolandone, F.; Mercier De Lepinay, B. F.; Meyer, B.; Momplaisir, R.; Granja, J. L.; Battani, A.; Burov, E. B.; Clouard, V.; Deschamps, R.; Gorini, C.; Hamon, Y.; LE Pourhiet, L.; Loget, N.; Lucazeau, F.; Pillot, D.; Poort, J.; Tankoo, K.; Cuevas, J. L.; Alcaide, J.; Poix, C. J.; Mitton, S.; Rodriguez, Y.; Schmitz, J.; Munoz Martin, A.

    2014-12-01

    The North America-Caribbean plate boundary is one of the least-known among large plate boundaries. Although it was identified early on as an example of a strike-slip fault in the north of Hispaniola, its structure and rate of motion remains poorly constrained. We present the first direct evidence for active sinistral strike-slip motion along this fault, based on swath seafloor mapping of the northern Haiti area. There is evidence for ~16.5 km of apparent strike-slip motion along the mapped segment of the Septentrional fault zone off Cap Haitien town which is terminated to the east onland Dominican republic and in the west to southern Cuban margin. By evaluating these new constraints within the context of geodetic models of global plate motions, we estimate an activity of the fault since 2 Ma with an angular velocity for the Caribbean plate relative to the North America predicted 6-12 mmyr-1 sinistral motion along the Septentrional fault zone. This transform fault was initiated around 20 million years ago in its western segment and since 2 Ma in its eastern segment in response to a regional reorganization of plate velocities and directions, which induced a change in configuration of plate boundaries.

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

    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.

  18. An unusual cause of recurrent joint effusions:nonhemophilic hemosiderotic synovitis of the knee

    Yalcin, Nadir; Bektaser, Bulent; Cicekli, Ozgur; Ugras, Serdar; Dogan, Metin

    2004-01-01

    A 20-year-old female presented with a painful swelling in the right knee and snapping sensation on joint motion that appeared without trauma and recurred several times. She had no history of a bleeding disease or trauma. Physical examination showed no signs of rash or temperature change or systemic or local findings of an infection. The knee was tender and knee motion was painful, with 90 degrees of flexion and full extension. The ballottement test was positive. All laboratory tests including...

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

    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

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

    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

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

    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)

  2. Traumatic knee extension deficit (the locked knee)

    Helmark, I C; Neergaard, K; Krogsgaard, M R

    2007-01-01

    In the present study we investigated the validity of magnetic resonance imaging (MRI) and arthroscopy in knees with acute, traumatic extension deficit (the "locked knee"), and evaluated whether arthroscopy of knees with no mechanical pathology could be avoided by MRI evaluation. The study consist......-handle lesion and one pathological synovial plica). MRI of the knee with acute, traumatic extension deficit is in the acute or subacute phase a safe method to identify the patients that have a mechanical reason for locking and therefore can benefit from arthroscopic treatment....

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

    I. Charvátová

    2000-01-01

    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 quasitr...

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

    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.

  5. Loss of knee-extension strength is related to knee swelling after total knee arthroplasty

    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)....

  6. Total Knee Replacement

    ... 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 ...

  7. Osteotomy of the knee

    ... 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. ...

  8. Knee MRI scan

    Abnormal results may be due to a sprain or tear of the ligaments in the knee area. Abnormal results may also be due to: Arthritis of the knee Avascular necrosis (also called osteonecrosis) Bone tumor or cancer Broken bone ...

  9. Partial knee replacement - slideshow

    ... 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

    ... 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

    ... 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. Knee arthroscopy - slideshow

    ... this page: //medlineplus.gov/ency/presentations/100117.htm Knee arthroscopy - series To use the sharing features on ... 5 out of 5 Normal anatomy Overview The knee is a complex joint made up of the ...

  13. Human movements and abstract motion displays activate different processes in the observer's motor system.

    Agosta, Sara; Battelli, Lorella; Casile, Antonino

    2016-04-15

    Brain imaging studies have shown that observation of both bodily movements and abstract motion displays complying with human kinematics activate the observer's motor cortex. However, it is unknown whether the same processes are active in the two conditions. Here, we addressed this issue using transcranial magnetic stimulation (TMS) to directly compare cortico-spinal excitability during observation of actions and motion stimuli that complied with or violated normal human kinematics. We found that kinematics significantly modulated the motor-evoked potentials (MEPs) produced by TMS during observation of both human and abstract motion stimuli. However, only the temporal unfolding of cortico-spinal excitability during observation of human movements significantly correlated with instantaneous stimulus velocity. This correlation was present for normal movements and also for a subset of the movements having unnatural kinematics. Furthermore, bodily movements for which we found no correlation between MEPs and stimulus velocity produced significantly higher MEPs. Our novel results suggest a dissociation in how human movements and abstract motion displays engage the observer's motor system. Specifically, while both stimulus types significantly activate the observer's motor cortex, only bodily movements produce patterns of cortico-spinal excitability that closely follow the velocity profile of the observed movement. This internal "re-enactment" of observed bodily movements seems to be only partially attuned to normal human kinematics. PMID:26854559

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

    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.

  15. Posterior knee pain

    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 ...

  16. Bicompartmental knee arthroplasty

    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...

  17. Knee joint replacement

    Knee joint replacement is a surgery to replace a knee joint with a man-made joint. The artificial joint is called a prosthesis . ... cartilage and bone are removed from the knee joint. Man-made pieces are then placed in the ...

  18. Actinomycosis of the Knee

    Yusof, Mohd Imran; Yusof, Abdul Halim; Salleh, Md Salzihan Md; HARUN, Azian

    2005-01-01

    We report a case of actinomycosis presenting as a knee swelling in a 34 year-old man. Knee actinomycosis poses a diagnosis challenge to clinicians as it is rare, often mimics knee tuberculosis and culture of the causative microbes is technically difficult. The classic microscopic appearance of this Gram-positive bacteria often forms the basis of diagnosis.

  19. Knee CT scan

    A computed tomography (CT) scan of the knee is a test that uses x-rays to take detailed images of the knee. ... A CT scan can quickly create more detailed pictures of the knee than standard x-rays. The test may be ...

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

    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.

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

    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

  2. Increased physical activity severely induces osteoarthritic changes in knee joints with papain induced sulfate-glycosaminoglycan depleted cartilage

    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...

  3. Fatigue Effects on Knee Joint Stability During Two Jump Tasks in Women

    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...

  4. Low-level intermittent quadriceps activity during transcranial direct current stimulation facilitates knee extensor force-generating capacity.

    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

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

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

    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

  7. Magnetic Resonance Imaging for Traumatic Knee Injury

    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.

  8. Knee Pain and the Weekend Warriors

    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 ...

  9. Knee Pain and the Weekend Warriors

    Full Text Available ... wispy filaments that one can see in the background as you’re showing us the cartilage and ... their job. These knees carry sometimes ten times body weight, and on an active person this particular patient ...

  10. Anterior knee pain

    Anterior knee pain is a common complain in all ages athletes. It may be caused by a large variety of injuries. There is a continuum of diagnoses and most of the disorders are closely related. Repeated minor trauma and overuse play an important role for the development of lesions in Hoffa's pad, extensor mechanism, lateral and medial restrain structures or cartilage surface, however usually an increase or change of activity is referred. Although the direct relation of cartilage lesions, especially chondral, and pain is a subject of debate these lesions may be responsible of early osteoarthrosis and can determine athlete's prognosis. The anatomy and biomechanics of patellofemoral joint is complex and symptoms are often unspecific. Transient patellar dislocation has MR distinct features that provide evidence of prior dislocation and rules our complication. However, anterior knee pain more often is related to overuse and repeated minor trauma. Patella and quadriceps tendon have been also implicated in anterior knee pain, as well as lateral or medial restraint structures and Hoffa's pad. US and MR are excellent tools for the diagnosis of superficial tendons, the advantage of MR is that permits to rule out other sources of intraarticular derangements. Due to the complex anatomy and biomechanic of patellofemoral joint maltracking is not fully understood; plain films and CT allow the study of malalignment, new CT and MR kinematic studies have promising results but further studies are needed. Our purpose here is to describe how imaging techniques can be helpful in precisely defining the origin of the patient's complaint and thus improve understanding and management of these injuries

  11. Evaluating knee replacement mechanics during ADL with PID-controlled dynamic finite element analysis.

    Fitzpatrick, Clare K; Baldwin, Mark A; Clary, Chadd W; Maletsky, Lorin P; Rullkoetter, Paul J

    2014-01-01

    Validated computational knee simulations are valuable tools for design phase development of knee replacement devices. Recently, a dynamic finite element (FE) model of the Kansas knee simulator was kinematically validated during gait and deep flexion cycles. In order to operate the computational simulator in the same manner as the experiment, a proportional-integral-derivative (PID) controller was interfaced with the FE model to control the quadriceps actuator excursion and produce a target flexion profile regardless of implant geometry or alignment conditions. The controller was also expanded to operate multiple actuators simultaneously in order to produce in vivo loading conditions at the joint during dynamic activities. Subsequently, the fidelity of the computational model was improved through additional muscle representation and inclusion of relative hip-ankle anterior-posterior (A-P) motion. The PID-controlled model was able to successfully recreate in vivo loading conditions (flexion angle, compressive joint load, medial-lateral load distribution or varus-valgus torque, internal-external torque, A-P force) for deep knee bend, chair rise, stance-phase gait and step-down activities. PMID:22687046

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

    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...

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

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

    2014-01-01

    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 sport...

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

    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.

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

    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.

  16. Association of Cross Linked C-Telopeptide II Collagen and Hyaluronic Acid with Knee Osteoarthritis Severity

    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.

  17. Evaluation of total knee mechanics using a crouching simulator with a synthetic knee substitute.

    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

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

    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

  19. IN VIVO MOTION OF FEMORAL CONDYLES DURING WEIGHT-BEARING FLEXION AFTER ANTERIOR CRUCIATE LIGAMENT RUPTURE USING BIPLANE RADIOGRAPHY

    Kaining Chen

    2013-09-01

    Full Text Available The purpose of this study was to investigate in vivo three- dimensional tibiofemoral kinematics and femoral condylar motion in knees with anterior cruciate ligament (ACL deficiency during a knee bend activity. Ten patients with unilateral ACL rupture were enrolled. Both the injured and contralateral normal knees were imaged using biplane radiography at extension and at 15°, 30°, 60°, 90°, and 120° of flexion. Bilateral knees were next scanned by computed tomography, from which bilateral three-dimensional knee models were created. The in vivo tibiofemoral motion at each flexion position was reproduced through image registration using the knee models and biplane radiographs. A joint coordinate system containing the geometric center axis of the femur was used to measure the tibiofemoral motion. In ACL deficiency, the lateral femoral condyle was located significantly more posteriorly at extension and at 15° (p < 0.05, whereas the medial condylar position was changed only slightly. This constituted greater posterior translation and external rotation of the femur relative to the tibia at extension and at 15° (p < 0.05. Furthermore, ACL deficiency led to a significantly reduced extent of posterior movement of the lateral condyle during flexion from 15° to 60° (p < 0.05. Coupled with an insignificant change in the motion of the medial condyle, the femur moved less posteriorly with reduced extent of external rotation during flexion from 15° to 60° in ACL deficiency (p < 0.05. The medial- lateral and proximal-distal translations of the medial and lateral condyles and the femoral adduction-abduction rotation were insignificantly changed after ACL deficiency. The results demonstrated that ACL deficiency primarily changed the anterior-posterior motion of the lateral condyle, producing not only posterior subluxation at low flexion positions but also reduced extent of posterior movement during flexion from 15° to 60°

  20. Interpolation function for approximating knee joint behavior in human gait

    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.

  1. Anteroposterior glide versus rotating platform low contact stress (LCS knee arthroplasty: a randomised controlled trial

    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

  2. Efficacy of multimodal cocktail periarticular injection with or without steroid in total knee arthroplasty

    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. Prediction of near-field strong ground motions for scenario earthquakes on active fault

    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.

  4. Semi-active Control of Shallow Cables with Magnetorheological Dampers under Harmonic Axial Support Motion

    Zhou, Q.; Nielsen, Søren R.K.; Qu, W.L.

    2007-01-01

    The paper deals with the control of sub- and superharmonic resonances by means of magnetorheological (MR) dampers of an inclined shallow cable caused by parametric excitation from harmonically varying support points. A mechanical model based on the Dahl hysteretic model is used to describe the...... dynamic property of the MR damper, and the finite difference method is used to discretize the derived governing nonlinear equations of motion of the cable-damper system. Semi-active control strategies are proposed based on the modulated homogeneous friction (SA-1) algorithm and the balance logic (SA-2......) algorithm. Four cases are analysed when the circular frequency O of the support point motion is in the vicinity of 2o1, o1, 2o1/3, and o1/2, o1 being the first in-plane eigenfrequency of the cable. The vibration reduction ability of the MR damper is compared with that of the viscous damper optimally tuned...

  5. Development of a hinge compatible with the kinematics of the knee joint.

    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

  6. Traumatic chylous knee effusion.

    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...

  7. Mechanisms of improved knee flexion after rectus femoris transfer surgery

    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...

  8. Modeling meiotic chromosome pairing: nuclear envelope attachment, telomere-led active random motion, and anomalous diffusion

    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.

  9. Active breathing control (ABC): Determination and reduction of breathing-induced organ motion in the chest

    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

  10. The use of active breathing control (ABC) to minimize breathing motion during radiation therapy

    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

  11. Respiratory Motion of The Heart and Positional Reproducibility Under Active Breathing Control

    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

  12. Management of Acute Combined ACL-Medial and Posteromedial Instability of the Knee.

    Medvecky, Michael J; Tomaszewski, Paul

    2015-06-01

    Medial collateral ligament (MCL) injuries are the most common ligamentous injury of the knee. The extent of injury can range from a minor first-degree (1-degree) sprain to an extensive third-degree (3-degree) sprain that can propagate across the knee, rupturing one or both cruciate ligaments, and result in a knee subluxation or dislocation. A common pattern involves the combined anterior cruciate ligament (ACL) and MCL injury that is the focus of this chapter. The vast majority of these combined medial-sided injuries are treated nonoperatively with delayed reconstruction of the ACL injury in athletically active individuals. The MCL and associated medial structures are carefully assessed on physical examination, and classification of injury is based upon abnormal limits of joint motion. In vitro cadaveric biomechanical testing has given us a better understanding of ligament deficiency and altered joint motion. Consistency in terminology is necessary for proper classification of injury and reproducible categorization of injury patterns to be able to compare both nonoperative and operative treatment of various injury patterns. PMID:25932883

  13. Medial collateral ligament injuries of the knee: current treatment concepts

    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...

  14. Motion or activity: their role in intra- and inter-subject variation in fMRI

    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...

  15. X-ray activity phased with planet motion in HD 189733?

    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...

  16. Total knee arthroplasty using computer assisted navigation in patients with severe valgus deformity of the knee

    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.

  17. Autograft reconstructions for bone defects in primary total knee replacement in severe varus knees

    Yatinder Kharbanda

    2014-01-01

    Full Text Available Background: Large posteromedial defects encountered in severe varus knees during primary total knee arthroplasty can be treated by cementoplasty, structural bone grafts or metallic wedges. The option is selected depending upon the size of the defect. We studied the outcome of autograft (structural and impaction bone grafting reconstruction of medial tibial bone defects encountered during primary total knee replacement in severe varus knees. Materials and Methods: Out of 675 primary varus knees operated, bone defects in proximal tibia were encountered in 54 knees. Posteromedial defects involving 25-40% of the tibial condyle cut surface and measuring more than 5 mm in depth were grafted using a structural graft obtained from cut distal femur or proximal tibia in 48 knees. For larger, peripheral uncontained vertical defects in six cases, measuring >25 mm in depth and involving >40% cut surface of proximal tibial condyle, impaction bone grafting with a mesh support was used. Results: Bone grafts incorporated in 54 knees in 6 months. There was no graft collapse or stress fractures, loosening or nonunion. The average followup period was 7.8 years (range 5-10 years. We observed an average postoperative increase in the Knee Society Score from 40 to 90 points. There was improvement in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC scores in terms of pain, stiffness and physical function during activities of daily living. Conclusion: Bone grafting for defects in primary total knee is justified as it is biological, available then and is cost effective besides preserving bone stock for future revisions. Structural grafts should be used in defects >5 mm deep and involving 25-40% of the cut proximal tibial condyle surface. For larger peripheral vertical defects, impaction bone grafting contained in a mesh should be done.

  18. Dynamic weight-bearing assessment of pain in knee osteoarthritis

    Klokker, Louise; Christensen, Robin; Wæhrens, Eva E;

    2016-01-01

    BACKGROUND: The Osteoarthritis Research Society International (OARSI) has suggested to asses pain after specific activities consistently in clinical trials on knee OA. The Dynamic weight-bearing Assessment of Pain (DAP) assesses pain during activity (30 s of performing repeated deep knee-bends from...

  19. Is Lifelong Knee Joint Force from Work, Home, and Sport Related to Knee Osteoarthritis?

    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...

  20. Effect of kinesio taping on the isokinetic muscle function in football athletes with a knee injury

    Hong, SoonKwon; Shim, Jemyung; Kim, SungJoong; Namkoong, Seung; Roh, HyoLyun

    2016-01-01

    [Purpose] The purpose of this study was to determine the difference in isokinetic muscle function in football athletes with a knee injury with and without kinesio taping. [Subjects] The subjects for this study were 10 football athletes (males) with a knee injury. [Methods] Measurements were performed by using Cybex dynamometer under uniform motion before and after the application of kinesio tape to the quadriceps and hamstring muscle. Maximal concentric knee extension and flexion at three ang...

  1. Large Intra-Articular Anterior Cruciate Ligament Ganglion Cyst, Presenting with Inability to Flex the Knee

    Philip Pastides; Davinder Paul Singh Baghla; Sreeram Penna; Vivek Gulati; Jake Sloane

    2010-01-01

    A 41-year-old female presented with a 3-month history of gradually worsening anterior knee pain, swelling and inability to flex the knee. Magnetic resonance imaging (MRI) revealed a large intra-articular cystic swelling anterior to the anterior cruciate ligament (ACL), extending into the Hoffa's infrapatellar fat pad. Following manipulation under anaesthesia and arthroscopic debridement of the cyst, the patient's symptoms were relieved with restoration of normal knee motion. ACL ganglion cyst...

  2. Diagnostic Value of Knee Arthrometry in the Prediction of ACL Strain During Landing

    Kiapour, Ata; Wordeman, Samuel Clayton; Paterno, Mark V.; Quatman, Carmen E.; Levine, Jason W.; Goel, Vijay K.; Hewett, Timothy E.

    2013-01-01

    Objectives: Excessive knee joint laxity may decrease overall joint stability and increase the risk of anterior cruciate ligament (ACL) injury during high risk activities. Despite the frequent clinical use of knee arthrometry, as an accurate and valid method for evaluation of knee laxity, no data exists to correlate instrumented laxity measures and ACL strain during dynamic high-risk activities. The purpose of this study was to evaluate relationships between instrumented anterior knee laxity m...

  3. HIGH TIBIAL OSTEOTOMY VERSUS UNICOMPARTMENTAL KNEE ARTHROPLASTY FOR MEDIAL COMPARTMENT ARTHROSIS OF THE KNEE: A REVIEW OF THE LITERATURE

    Dettoni, Federico; Bonasia, Davide Edoardo; Castoldi, Filippo; BRUZZONE, MATTEO; Blonna, Davide; Rossi, Roberto

    2010-01-01

    This review examined the literature regarding high tibial osteotomy (HTO) and imicompartmental knee arthroplasty (UKA), focusing on indications, survivorship and functional outcomes of the two procedures, as well as revision to total knee arthroplasty (TKA) after failed HTO or UKA. HTO and UKA share the same indications in selected cases of medial unicompartmental knee arthrosis. These indications include patients who are: 1) 55 to 65 years old; 2) moderately active; 3) non-obese; 4) have mil...

  4. Preventing Knee Injuries

    ... 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 ...

  5. Revision Knee Surgery

    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. ...

  6. Revision Knee Surgery

    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 ...

  7. Bicompartmental knee arthroplasty

    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

  8. Musculoskeletal MR: knee

    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.)

  9. Musculoskeletal MR: knee

    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.)

  10. Bicompartmental knee arthroplasty.

    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

  11. Semi-active control of the rocking motion of monolithic art objects

    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.

  12. Total Knee Replacement for Women

    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. ...

  13. Risk analysis of occupational factors influencing the development of arthrosis of the knee

    The aim of this study was to identify occupational activities important for the development of arthrosis of the knee, taking into account the confounding factors that were suspected or could be recognized. In the archives of the Department of Diagnostic Radiology at the Malmoe University Hospital all radiographs of weight-bearing knees of patients with painful knee joints from the period 1982-1986 were reassessed. We found 340 probands, i.e., subjects with arthrosis of the knee of at least grade 1 in the Ahlbaeck classification. These probands and their age- and sex-matched controls (680) were analyzed by a validated questionnaire for details of activities at work inducing knee moment over three 15-year-periods as well as their history of knee injuries at work or in their leisure time. The questionnaire was answered by 266 (79%) arthrosis probands and 463 controls (70%). The results of the questionnaire answers and of the recorded history of knee injuries were statistically analyzed by logistic regression. The relative risk of knee arthrosis was slightly increased (RR: 1.9; CI: 1.4-2.7) in probands with weight-bearing knee bending, i.e., dynamic load of the knee joint when bending, whereas knee injuries (meniscectomies and haemarthrosis) were associated with a higher risk. Weight-bearing knee bending corrected for confounders was not a significant factor for knee arthrosis. Overweight was observed to increase the relative risk. A sedentary profession had, on the other hand, a low risk. The knee injuries (66) were, but for 9 probands, sustained in leisure activities, mainly soccer. We thus conclude that work which induces weight-bearing knee bending by itself does not significantly increase the risk of developing arthrosis of the knee - knee injuries and overweight are more important

  14. The Mechanistic Connection Between the Trunk, Knee, and Anterior Cruciate Ligament Injury

    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.

  15. Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients

    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. Pixel-by-pixel analysis of DCE-MRI curve shape patterns in knees of active and inactive juvenile idiopathic arthritis patients

    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 trans), extravascular space fractional volume (Ve) and reverse volume transfer constant (kep) 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.)

  17. Real-time magnetic resonance imaging (MRI during active wrist motion--initial observations.

    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.

  18. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting.

    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

  19. Gait patterns after intraarticular treatment of patients with osteoarthritis of the Knee - Hyaluronan versus triamcinolone: a prospective, randomized, doubleblind, monocentric study

    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.

  20. Soft tissue twisting injuries of the knee

    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

  1. Outcomes of Varus Valgus Constrained Versus Rotating-Hinge Implants in Total Knee Arthroplasty.

    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 (Puniversal 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. PMID:26730689

  2. Assessing changes in subjective and objective function from pre- to post-knee arthroplasty using the Cardiff Dempster–Shafer theory classifier

    Worsley, Peter; Whatling, G.; Barrett, D S; Holt, C; Stokes, M.; M. Taylor

    2015-01-01

    The purpose of this study is to assess changes in subjective and objective function from pre- to post-knee arthroplasty (KA) using a combined classifier technique. Twenty healthy adults (50–80 years) and 31 KA patients (39–81 years) were studied (4 weeks pre- and 6 months post-KA). Questionnaire measures of subjective pain, joint stability, activity and function were collected. Objective functional assessment included goniometry, ultrasound imaging and 3-D motion analysis/inverse modelling of...

  3. Initial experience with active breathing control of liver motion during ventilation

    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

  4. Acute Effects of Foot Rotation in Healthy Adults during Running on Knee Moments and Lateral-Medial Shear Force.

    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

  5. Wearable Sensor-Based Rehabilitation Exercise Assessment for Knee Osteoarthritis

    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.

  6. A Highly Backdrivable, Lightweight Knee Actuator for Investigating Gait in Stroke

    SULZER, JAMES S.; Roiz, Ronald A.; Peshkin, Michael A.; Patton, James L.

    2009-01-01

    Many of those who survive a stroke develop a gait disability known as stiff-knee gait (SKG). Characterized by reduced knee flexion angle during swing, people with SKG walk with poor energy efficiency and asymmetry due to the compensatory mechanisms required to clear the foot. Previous modeling studies have shown that knee flexion activity directly before the foot leaves the ground, and this should result in improved knee flexion angle during swing. The goal of this research is to physically t...

  7. Biomechanical analysis of fixed bearing and mobile bearing total knee prostheses

    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. A randomized clinical trial of a peri-operative behavioral intervention to improve physical activity adherence and functional outcomes following total knee replacement

    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. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting

    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. Measurements of Generated Energy/Electrical Quantities from Locomotion Activities Using Piezoelectric Wearable Sensors for Body Motion Energy Harvesting

    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.

  11. Dopamine Activation Preserves Visual Motion Perception Despite Noise Interference of Human V5/MT

    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

  12. A Passive Dynamic Walking Model Based on Knee-Bend Behaviour: Stability and Adaptability for Walking Down Steep Slopes

    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.

  13. Recommended survey designs for occupancy modelling using motion-activated cameras: insights from empirical wildlife data

    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

  14. Aftershock activity of the 2015 Gorkha, Nepal, earthquake determined using the Kathmandu strong motion seismographic array

    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.

  15. Active Head Motion Compensation of TMS Robotic System Using Neuro-Fuzzy Estimation

    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.

  16. Method and effect of total knee arthroplasty osteotomy and soft tissue release for serious knee joint space narrowing

    Yulou Si

    2015-01-01

    Full Text Available To discuss the method and effect of total knee arthroplasty osteotomy and soft tissue release for serious knee joint space narrowing. Clinical data of 80 patients from October 2013 to December 2014 was selected with a retrospective method. All patients have undergone total knee arthroplasty. Then the X-rays plain film in weight loading was measured before and after operation and osteotomy was performed accurately according to the knee joint scores and the conditions of lower limb alignments. The average angle of tibial plateau osteotomy of postoperative patients was 4.3°, and the corrective angle of soft tissue balancing was 10.7°; the postoperative patients’ indicies including range of joint motion, knee joint HSS score, angle between articular surfaces, tibial angle, femoral-tibial angle and flexion contracture were distinctly better than the preoperative indicies (p<0.05 and the differences were statistically significant; the postoperative patients’ flexion contracture and range of joint motion were distinctly better than the preoperative indicies (p<0.05 and the differences were statistically significant. The effective release of the soft tissue of the posterior joint capsule under direct vision can avoid excess osteotomy and get satisfactory knee replacement space without influencing the patients’ joint recovery.

  17. Bioinspired Knee Joint for a Power-Assist Suit

    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.

  18. Preoperative Planning in Primary Total Knee Arthroplasty.

    Tanzer, Michael; Makhdom, Asim M

    2016-04-01

    Preoperative planning is of paramount importance in primary total knee arthroplasty. A thorough preoperative analysis helps the surgeon envision the operation, anticipate any potential issues, and minimize the risk of premature implant failure. Obtaining a thorough history is critical for appropriate patient selection. The physical examination should evaluate the integrity of the soft tissues, the neurovascular status, range of motion, limb deformity, and the status of the collateral ligaments to help determine the soft-tissue balancing and constraint strategy required. Standard radiographs, with a known magnification, should be obtained for preoperative total knee arthroplasty templating. Routine standing AP, lateral, and skyline radiographs of the knee can help the surgeon plan the bone cuts and tibial slope as well as the implant size and position at the time of surgery. In certain circumstances, such as severe coronal deformities, bone deficiencies, and/or extra-articular deformities, additional measures are frequently necessary to successfully reconstruct the knee. Constrained implants, metal augments, and bone graft must be part of the surgeon's armamentarium. PMID:26990712

  19. Effect of Mulligan's and Kinesio knee taping on adolescent ballet dancers knee and hip biomechanics during landing.

    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

  20. Knee Pain during Strength Training Shortly following Fast-Track Total Knee Arthroplasty

    Bandholm, Thomas; Thorborg, Kristian; Lunn, Troels Haxholdt;

    2014-01-01

    BACKGROUND: Loading and contraction failure (muscular exhaustion) are strength training variables known to influence neural activation of the exercising muscle in healthy subjects, which may help reduce neural inhibition of the quadriceps muscle following total knee arthroplasty (TKA). It is...... unknown how these exercise variables influence knee pain after TKA. OBJECTIVE: To investigate the effect of loading and contraction failure on knee pain during strength training, shortly following TKA. DESIGN: Cross-sectional study. SETTING: Consecutive sample of patients from the Copenhagen area, Denmark......, receiving a TKA, between November 2012 and April 2013. PARTICIPANTS: Seventeen patients, no more than 3 weeks after their TKA. MAIN OUTCOME MEASURES: In a randomized order, the patients performed 1 set of 4 standardized knee extensions, using relative loads of 8, 14, and 20 repetition maximum (RM), and...

  1. What Are Knee Problems?

    ... 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 ...

  2. Revision Knee Surgery

    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 ...

  3. Revision Knee Surgery

    Full Text Available ... and I will ream. Now this was a hybrid knee it looked like on the radiograph; is ... that’s surprising though, we’re almost doing a hybrid cement technique. Where there is no TM or ...

  4. Jumper's Knee (Patellar Tendonitis)

    ... 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 ...

  5. Revision Knee Surgery

    Full Text Available ... instruments or that allow for abbreviated surgical technique. These instruments allow us to use the LCCK implants, ... the knee. When she presented to me with these X-rays, my first concern was infection because ...

  6. Revision Knee Surgery

    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 ...

  7. Anterior knee pain

    ... or playing soccer). You have flat feet. Anterior knee pain is more common in: People who are overweight People who have had a dislocation, fracture, or other injury to the kneecap Runners, jumpers, ...

  8. Revision Knee Surgery

    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 ...

  9. Knee MRI scan

    MRI - knee ... radiologist see certain areas more clearly. During the MRI, the person who operates the machine will watch ... less anxious. Your provider may suggest an "open" MRI, in which the machine is not as close ...

  10. Arthritic Pain Relief through Partial Knee Replacement

    Full Text Available ... the inner aspect of her knee, what we call the medial compartment of her knee, she's got ... only one part of the knee, what we call a compartment of the knee, when one compartment ...

  11. Muscle activity and hand motion in veterinarians performing laparoscopic training tasks with a box trainer.

    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

  12. Dashboard (in the) knee.

    Patel, M S; Qureshi, A A; Green, T P

    2015-03-01

    We present the case of a 19-year-old individual presenting to an orthopaedic outpatient clinic several months following a dashboard knee injury during a road traffic accident with intermittent mechanical symptoms. Despite unremarkable examination findings and normal magnetic resonance imaging, the patient was identified subsequently as having an intra-articular plastic foreign body consistent with a piece of dashboard on arthroscopic knee assessment, the retrieval of which resulted in a complete resolution of symptoms. PMID:25723676

  13. Reading Knee-Deep

    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…

  14. Device-length changes and implant function following surgical implantation of the KineSpring in cadaver knees

    McNicholas MJ

    2015-01-01

    Full Text Available Michael J McNicholas,1 Stefan M Gabriel,2 Anton G Clifford,2 Evelyne M Hasler2 1Aintree University Hospital, Teaching Hospital, Major Trauma Centre, NHS Foundation Trust, Liverpool, UK; 2Moximed, Hayward, CA, USA Introduction: The KineSpring implant system has been shown to provide load reductions at the medial compartment of the knee, and has demonstrated clinical success in reducing pain and increasing function in patients with medial knee osteoarthritis. These results depend on the ability of the KineSpring to rotate, lengthen, and shorten to accommodate knee motions, and in response to knee position and loading. Purpose: The present study was undertaken to determine length changes of the implanted KineSpring in response to a range of knee positions, external knee loads, and placements by different orthopedic surgeons. Materials and methods: KineSpring system components were implanted in ten cadaver leg specimens by ten orthopedic surgeons, and absorber-length changes were measured under combined loading and in different positions of the knee. Results and conclusion: Spring compression consistent with knee-load reduction, and device lengthening and shortening to accommodate knee loads and motions were seen. These confirm the functionality of the KineSpring when implanted medially to the knee. Keywords: KineSpring, knee, function, preservation, offloading, osteoarthritis

  15. Elastic Knee Sleeves Limit Anterior Tibial Translation in Healthy Females

    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

  16. 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

    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

  17. Avaliação da amplitude articular do joelho: correlação entre as medidas realizadas com o goniômetro universal e no dinamômetro isocinético Knee joint range-of-motion evaluation: correlation between measurements achieved using a universal goniometer and an isokinetic dynamometer

    LH Batista

    2006-01-01

    Full Text Available CONTEXTUALIZAÇÃO: O instrumento mais utilizado pelos terapeutas para mensuração da amplitude de movimento (ADM articular é o goniômetro universal. No entanto, há carência de estudos que analisem a confiabilidade das medidas da ADM do joelho realizadas no dinamômetro isocinético. OBJETIVO: O objetivo deste estudo foi analisar a correlação entre as medidas de ADM na articulação do joelho, realizadas com o goniômetro universal e no dinamômetro isocinético. MÉTODO: Foram avaliados 38 voluntários saudáveis (27 mulheres, 11 homens, com idade de 36 ± 11 anos, com limitação mínima de 20° na ADM de extensão do joelho. No membro dominante de cada sujeito foram realizadas três mensurações da ADM do joelho com o goniômetro e três mensurações no dinamômetro. RESULTADOS: Os resultados deste estudo mostraram que há alto grau de correlação entre as medidas da ADM do joelho obtidas com o goniômetro universal e no dinamômetro isocinético (Coeficiente de Correlação de Pearson = 0,90. CONCLUSÃO: Com os procedimentos realizados, tanto o goniômetro universal como o dinamômetro isocinético podem ser utilizados para avaliação da ADM do joelho, pois ambos apresentam mensurações confiáveis.BACKGROUND: The instrument most often used by therapists for measuring joint range of motion (ROM is the universal goniometer. However, there is a lack of studies analyzing the reliability of knee joint ROM measured by the isokinetic dynamometer. OBJECTIVE: The purpose of this study was to analyze the correlation between the knee joint ROM measurements made using a universal goniometer and an isokinetic dynamometer. METHOD: 38 healthy volunteers (27 women, 11 men aged 36 ± 11 years were evaluated. All of them had a minimum knee extension ROM limitation of 20°. Three knee ROM measurements were made using the universal goniometer and another three using the isokinetic dynamometer, on each subject's dominant limb. RESULTS: The results

  18. Prevalence of pathologic findings in asymptomatic knees of marathon runners before and after a competition in comparison with physically active subjects - a 3.0 T magnetic resonance imaging study

    To determine the prevalence of pathologic findings in asymptomatic knees of marathon runners before and after a competition in comparison with physically active subjects. To compare the diagnostic performance of cartilage-dedicated magnetic resonance imaging (MRI) sequences at 3.0 T. Ten marathon runners underwent 3.0 T MRI 2-3 days before and after competition. Twelve physically active asymptomatic subjects not performing long-distance running were examined as controls. Pathologic condition was assessed with the whole-organ magnetic resonance imaging score (WORMS). Cartilage abnormalities and bone marrow edema pattern (BMEP) were quantified. Visualization of cartilage pathology was assessed with intermediate-weighted fast spin-echo (IM-w FSE), fast imaging employing steady-state acquisition (FIESTA) and T1-weighted three-dimensional (3D) high-spatial-resolution volumetric fat-suppressed spoiled gradient-echo (SPGR) MRI sequences. Eight of ten marathon runners and 7/12 controls showed knee abnormality. Slightly more and larger cartilage abnormalities, and BMEP, in marathon runners yielded higher but not significantly different WORMS (P > 0.05) than in controls. Running a single marathon did not alter MR findings substantially. Cartilage abnormalities were best visualized with IM-w FSE images (P < 0.05). A high prevalence of knee abnormalities was found in marathon runners and also in active subjects participating in other recreational sports. IM-w FSE sequences delineated more cartilage MR imaging abnormalities than did FIESTA and SPGR sequences. (orig.)

  19. Motion compensation for brain PET imaging using wireless MR active markers in simultaneous PET-MR: phantom and non-human primate studies

    Huang, Chuan; Ackerman, Jerome L.; Petibon, Yoann; Normandin, Marc D.; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong

    2014-01-01

    Brain PET scanning plays an important role in the diagnosis, prognostication and monitoring of many brain diseases. Motion artifacts from head motion are one of the major hurdles in brain PET. In this work, we propose to use wireless MR active markers to track head motion in real time during a simultaneous PET-MR brain scan and incorporate the motion measured by the markers in the listmode PET reconstruction.

  20. Experience of a mobilization and active exercise program on the range of motion of bedridden patients with disuse syndrome

    Fernandes, Teresa de Jesus; Mendes, Eugénia; Preto, Leonel; Novo, André

    2015-01-01

    Disuse syndrome is a disorder that is most often associated with acute or chronic disease complications. Despite disuse syndrome may affect all organs and systems, the impact of range of motion limitations caused by immobility on functional capacity to perform activities of daily living is often very severe. Mobilization and active exercise have beneficial effects that counteract the impact of immobility on the body. Objective: This study aims to assess the effect of a mobilization and active...

  1. Effect of a mobilization and active exercise program on the range of motion of bedridden patients with disuse syndrome

    Fernandes, Teresa de Jesus; Mendes, Eugénia; Preto, Leonel; Novo, André

    2015-01-01

    Disuse syndrome is a disorder that is most often associated with acute or chronic disease complications. Despite disuse syndrome may affect all organs and systems, the impact of range of motion limitations caused by immobility on functional capacity to perform activities of daily living is often very severe. Mobilization and active exercise have beneficial effects that counteract the impact of immobility on the body. This study aims to assess the effect of a mobilization and active exercis...

  2. Detection of active sacroiliitis with ankylosing spondylitis through intravoxel incoherent motion diffusion-weighted MR imaging

    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.)

  3. Are both the knees of the same size? Analysis of component asymmetry in 289 bilateral knee arthroplasties

    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.

  4. Inverse Dynamics and the Immeasurable Motions

    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...

  5. 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

    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.

  6. Human motion energy harvesting using a piezoelectric MFC patch.

    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

  7. Total Knee Replacement for Women

    Full Text Available ... get it as close to the knee, the hip, and the ankle being in perfect alignment, and ... there was a long-term results with cemented hips and cemented knees reported in the Swedish registry ...

  8. Minimally Invasive Total Knee Arthroplasty

    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 ...

  9. Total Knee Replacement for Women

    Full Text Available ... The initial setting for the distal femoral resection guide is making these parallel to the posterior condyle. ... does this knee differ from the high-flex mobile bearing knee?” Well this is not a mobile ...

  10. Minimally Invasive Total Knee Arthroplasty

    Full Text Available ... female. The knee is a little -- I would grade it a one plus lax knee but it’s ... and/or rapid aware problems. Heavy hookup, please. Good point. Just make sure you do it well, ...

  11. Minimally Invasive Total Knee Arthroplasty

    Full Text Available ... Institute. We're going to be doing an MIS total knee arthroplasty with the Zimmer mobile bearing ... this point. And there is many recipes for MIS knee surgery as there are surgeons. What’s kind ...

  12. Total Knee Replacement for Women

    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 ...

  13. MedlinePlus: Knee Replacement

    ... 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 ...

  14. Strategies for the prevention of knee osteoarthritis

    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....... Instead, OA should be viewed as a chronic condition, where prevention and early comprehensive-care models are the accepted norm, as is the case with other chronic diseases. Joint injury, obesity and impaired muscle function are modifiable risk factors amenable to primary and secondary prevention......-the regimes. Now is the time to begin the era of personalized prevention for knee OA....

  15. Comparative study of joint range of motion in children between 7 and 12 years of age from different gender

    S.I.L. Melo

    2011-01-01

    Full Text Available The aim of the study was to evaluate and compare active and passive joint range of motion in children in relation to gender and age. This study involved 103 children (43 boys and 60 girls categorized into two groups: G1 (7 to 9 years old and G2 (10 to 12 years old. The flexitest protocol, active and passive, and the SAPO® were used to evaluate joint range of motion. A paired t test was applied to compare active and passive joint range of motion and an independent t test (p < .05 was used to compare active and passive range of motion between gender and age. Results showed that the passive joint ranges of motion of the lower limbs are higher than active motion (p < .001. Girls presented greater passive ankle flexion than boys did (p = .002. Children between 7 and 12 years of age presented similar standards of joint range of motion of low limb. Significant differences were found between passive and active angular range of motion in the hip, knee and ankle. There were no differences between boys and girls in the joint range of motion as well as among age groups.

  16. Assessment of Knee Proprioception in the Anterior Cruciate Ligament Injury Risk Position in Healthy Subjects: A Cross-sectional Study

    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...

  17. Getting your home ready - knee or hip surgery

    ... 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 ...

  18. Relationship between static anterior laxity using the KT-1000 and dynamic tibial rotation during motion in patients with anatomical anterior cruciate ligament reconstruction.

    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

  19. Active-flux based motion sensorless vector control of biaxial excitation generator/motor for automobiles (BEGA)

    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...

  20. Minimally Invasive Total Knee Arthroplasty

    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 ...

  1. Prevalent knee pain and sport

    Hahn, Thomas; Foldspang, Anders

    1998-01-01

    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...

  2. Minimally Invasive Total Knee Arthroplasty

    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 ...

  3. A framework for activity detection in wide-area motion imagery

    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.

  4. Stochastic non-circular motion and outflows driven by magnetic activity in the Galactic bulge region

    Suzuki, Takeru K.; Fukui, Yasuo; Torii, Kazufumi; Machida, Mami; Matsumoto, Ryoji

    2015-12-01

    By performing a global magnetohydrodynamical simulation for the Milky Way with an axisymmetric gravitational potential, we propose that spatially dependent amplification of magnetic fields possibly explains the observed noncircular motion of the gas in the Galactic centre region. The radial distribution of the rotation frequency in the bulge region is not monotonic in general. The amplification of the magnetic field is enhanced in regions with stronger differential rotation, because magnetorotational instability and field-line stretching are more effective. The strength of the amplified magnetic field reaches ≳0.5 mG, and radial flows of the gas are excited by the inhomogeneous transport of angular momentum through turbulent magnetic field that is amplified in a spatially dependent manner. In addition, the magnetic pressure-gradient force also drives radial flows in a similar manner. As a result, the simulated position-velocity diagram exhibits a time-dependent asymmetric parallelogram-shape owing to the intermittency of the magnetic turbulence; the present model provides a viable alternative to the bar-potential-driven model for the parallelogram shape of the central molecular zone. This is a natural extension into the central few 100 pc of the magnetic activity, which is observed as molecular loops at radii from a few 100 pc to 1 kpc. Furthermore, the time-averaged net gas flow is directed outward, whereas the flows are highly time dependent, which we discuss from a viewpoint of the outflow from the bulge.

  5. A framework for activity detection in wide-area motion imagery

    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.

  6. Noise-enhanced stability and double stochastic resonance of active Brownian motion

    Zeng, Chunhua; Zhang, Chun; Zeng, Jiakui; Liu, Ruifen; Wang, Hua

    2015-08-01

    In this paper, we study the transient and resonant properties of active Brownian particles (ABPs) in the Rayleigh-Helmholtz (RH) and Schweitzer-Ebeling-Tilch (SET) models, which is driven by the simultaneous action of multiplicative and additive noise and periodic forcing. It is shown that the cross-correlation between two noises (λ) can break the symmetry of the potential to generate motion of the ABPs. In case of no correlation between two noises, the mean first passage time (MFPT) is a monotonic decrease depending on the multiplicative noise, however in case of correlation between two noises, the MFPT exhibits a maximum, depending on the multiplicative noise for both models, this maximum for MFPT identifies the noise-enhanced stability (NES) effect of the ABPs. By comparing with case of no correlation (λ =0.0 ), we find two maxima in the signal-to-noise ratio (SNR) depending on the cross-correlation intensity, i.e. the double stochastic resonance is shown in both models. For the RH model, the SNR exhibits two maxima depending on the multiplicative noise for small cross-correlation intensity, while in the SET model, it exhibits only a maximum depending on the multiplicative noise. Whether λ =0.0 or not, the MFPT is a monotonic decrease, and the SNR exhibits a maximum, depending on the additive noise in both models.

  7. Personalized Multilayer Daily Life Profiling Through Context Enabled Activity Classification and Motion Reconstruction: An Integrated System Approach.

    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

  8. Knee Pain and the Weekend Warriors

    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 ...

  9. Arthritic Pain Relief through Partial Knee Replacement

    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 ...

  10. Avoidance of activity and disability in patients with osteoarthritis of the knee: the mediating role of muscle strength.

    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

  11. Extremely Reduced Motion in Front of Screens: Investigating Real-World Physical Activity of Adolescents by Accelerometry and Electronic Diary

    Streb, Judith; Kammer, Thomas; Spitzer, Manfred; Hille, Katrin

    2015-01-01

    This paper reports accelerometer and electronic dairy data on typical daily activities of 139 school students from grade six and nine. Recordings covered a typical school day for each student and lasted on average for 23 h. Screen activities (watching television and using the computer) are compared to several other activities performed while sitting (e.g., playing, eating, sitting in school, and doing homework). Body movement was continuously recorded by four accelerometers and transformed into a motion sore. Our results show that extremely low motion scores, as if subjects were freezing, emerge to a greater extent in front of screens compared to other investigated activities. Given the substantial amount of time young people spend in front of screens and the rising obesity epidemic, our data suggest a mechanism for the association of screen time and obesity. PMID:25955531

  12. Biomechanical risk factors and mechanisms of knee injury in golfers.

    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

  13. Study of Wearable Knee Assistive Instruments for Walk Rehabilitation

    Zhu, Yong; Nakamura, Masahiro; Ito, Noritaka; Fujimoto, Hiroshi; Horikuchi, Kenichi; Wakabayashi, Shojiro; Takahashi, Rei; Terada, Hidetsugu; Haro, Hirotaka

    A wearable Knee Assistive Instrument for the walk rehabilitation was newly developed. Especially, this system aimed at supporting the rehabilitation for the post-TKA (Total Knee Arthroplasty) which is a popular surgery for aging people. This system consisted of an assisting mechanism for the knee joint, a hip joint support system and a foot pressure sensor system. The driving system of this robot consisted of a CPU board which generated the walking pattern, a Li-ion battery, DC motors with motor drivers, contact sensors to detect the state of foot and potentiometers to detect the hip joint angle. The control method was proposed to reproduce complex motion of knee joint as much as possible, and to increase hip or knee flexion angle. Especially, this method used the timing that heel left from the floor. This method included that the lower limb was raised to prevent a subject's fall. Also, the prototype of knee assisting system was tested. It was confirmed that the assisting system is useful.

  14. Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis

    Kim, Jung-Hwan; Ji, Sang-Goo; Jung, Kang-Jae

    2016-01-01

    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

  15. Therapeutic Experience on Stance Control Knee-Ankle-Foot Orthosis With Electromagnetically Controlled Knee Joint System in Poliomyelitis.

    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

  16. Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty?

    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...

  17. Influence of surface active substances on bubble motion and collision with various interfaces.

    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

  18. Ground motion parameters of Shillong plateau: One of the most seismically active zones of northeastern India

    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.

  19. Torn discoid lateral meniscus treated with arthroscopic meniscectomy: observations in 62 knees

    LU Ying; LI Qiang; HAO Jie

    2007-01-01

    Background Discoid lateral meniscus of the knee is common in Chinese population. There has been considerable debate about the best treatment for discoid lateral meniscus tears. The purpose of this study was to observe the effect of arthroscopic meniscectomy for the treatment of discoid lateral meniscus tears.Methods Between July 1999 and December 2004, arthroscopic meniscectomy was performed on 62 menisci of 57 patients with discoid lateral meniscus tears (52 unilateral, 5 bilateral). 41 menisci were "complete discoid meniscus", 21 "incomplete". According to the extent of the meniscus tears, partial meniscectomy was performed on 52 knees, total meniscectomy on 7 knees, and partial meniscectomy combined with meniscus suture on 3 knees through an arthroscope.After the operations, early rehabilitation training programs, including straight-leg-raising and range-of-motion exercises,were carried out. 51 patients were followed up for 1 year 2 months to 6 years 5 months (mean, 3 years 3 months), 6 patients were lost. Lysholm-Ⅱ scoring system was used to assess the function of the knee joints before the operation and during the follow-up.Results The operations on all the 62 knees were successful without complications. The patients could walk normally after completing the 2-week postoperation rehabilitation program. After 3-4 weeks they could lead a normal life and participate in a moderate amount of sports or other physical activities. The mean Lysholm-Ⅱ score was 89 (60-100)during the follow-up, which was significantly higher than that before the operation (50, range 34-74; P<0.01). 88% of the patients achieved excellent or good clinical results.Conclusions Arthroscopic meniscectomy is an alternative for treatment of discoid lateral meniscus tears with minimal traumatic effects. It can achieve early mobilization and a low complication rate, as well as the preservation of the meniscus structure and functions to the largest extent. In combination with proper

  20. Anterior approach for knee arthrography

    Objective. To develop a new method of magnetic resonance arthrography (MRA) of the knee using an anterior approach analogous to the portals used for knee arthroscopy.Design. An anterior approach to the knee joint was devised mimicking anterior portals used for knee arthroscopy. Seven patients scheduled for routine knee MRA were placed in a decubitus position and under fluoroscopic guidance a needle was advanced from a position adjacent to the patellar tendon into the knee joint. After confirmation of the needle tip location, a dilute gadolinium solution was injected.Results and conclusion. All the arthrograms were technically successful. The anterior approach to knee MRA has greater technical ease than the traditional approach with little patient discomfort. (orig.)

  1. A kinematic assessment of knee prosthesis from fluoroscopy images

    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)

  2. Human Control Law and Brain Activity of Voluntary Motion by Utilizing a Balancing Task with an Inverted Pendulum

    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.

  3. Revision Knee Surgery

    Full Text Available ... and floating, which would probably not provide any benefit. Yeah, which is 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 ...

  4. Hypermobility and Knee Injuries.

    Steiner, Mark E.

    1987-01-01

    A review of research on the effect of hypermobility on knee injury indicates that greater than normal joint flexibility may be necessary for some athletic endeavors and that it may be possible to change one's underlying flexibility through training. However, for most athletes, inherited flexibility probably plays only a small role, if any, in…

  5. Knee Bracing: What Works?

    ... and flexibility are important for holding down knee pain and injuries. You should work out an exercise plan with your doctor to ... afp/20000115/411.html) Braces and Splints for Musculoskeletal Conditions by JR Gravlee, M.D., and DJ Van Durme, M.D. (American Family Physician February 01, 2007, ... Created: 09/00

  6. Active control of the attitude motion and structural vibration of a flexible satellite by jet thrusters

    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

  7. MRI EVALUATION OF PAINFUL KNEE: A STUDY AT KATURI TERTIARY REFERRAL CENTER

    Bhimeswarao Pasupuleti

    2015-02-01

    Full Text Available INTRODUCTION: Normal knee joint functional activity is essential for day to day life . The number of patients with complaints of painful knee joint is quite significant and therefore magnetic resonance imaging (MRI of the knee is of great value in understanding and to diagnose the varied pathologies causing painful knee joint. The information obtained from conventional radiographs of the knee is limited, and by CT scans is limited to bone pathog l y with limited information about ligaments and synovium. AIMS AND OBJECTIVES : a To describe the MRI features in various types of traumatic and non - traumatic knee pain . b To identify the common lesions seen in the knee joint . METHODOLOGY : The study population included 100 patients who underwent MR imaging of the knee who presented with knee pain to the DEPARTMENT OF RADIOLOGY, KATURI MEDICALCOLLEGE referred by the clinician. STUDY PERIOD: Nov 2010 to Oct 2012 . STUDY DESIGN : Descriptive study . All the MRI scans of the knee in this study were performed using GE Signa Profile EXCITE MR machine with a 0.2 tesla field strength magnet in a closely coupled extremity coil. RESULTS AND DISCUSSION : The pathology of knee joint is broadly classified as traumatic and non - traumatic. Traumatic pathol o gy mainly included the ligament injuries and non - traumatic included arthritis, cysts and neoplastic lesions

  8. A Comparison of Two Motion Sensors for the Assessment of Free-Living Physical Activity of Adolescents

    Roman Cuberek

    2010-04-01

    Full Text Available This study assessed and compared the daily step counts recorded by two different motion sensors in order to estimate the free-living physical activity of 135 adolescent girls. Each girl concurrently wore a Yamax pedometer and an ActiGraph accelerometer (criterion measure every day for seven consecutive days. The convergent validity of the pedometer can be considered intermediate when used to measure the step counts in free-living physical activity; but should be considered with caution when used to classify participants’ step counts into corresponding physical activity categories because of a likelihood of ‘erroneous’ classification in comparison with the accelerometer.

  9. Parallax-sensitive remapping of visual space in occipito-parietal alpha-band activity during whole-body motion.

    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

  10. Active Motion of Tectonic Blocks in East Asia: Evidence from GPS Measurement

    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.

  11. The pendulum test as a tool to evaluate passive knee stiffness and viscosity of patients with rheumatoid arthritis

    Vinci Maria; Garozzo Rosaria; Sgarlata Rosaria; Casabona Antonino; Valle Maria S; Cioni Matteo

    2006-01-01

    Abstract Background The pendulum test of Wartenberg is a technique commonly used to measure passive knee motion with the aim to assess spasticity. We used this test to evaluate changes of the knee angular displacement, passive stiffness and viscosity in rheumatoid arthritis patients. Stiffness and viscosity represent passive resistances to joint motion associated with the structural properties of the joint tissue and of the muscular-tendon complex. Stiffness can be considered an intrinsic pro...

  12. Proprioception in Above-the-Knee Amputees with Artificial Limbs

    E. P. Latanioti

    2013-01-01

    Full Text Available Purpose. To evaluate the lower limb proprioceptive sensation in patients with femoral amputation who received an artificial joint. Materials and Methods. 22 patients (18 men, 4 women, 24–65 years old (mean: 42, who had undergone above-the-knee joint amputation and underwent evaluation of proprioception using joint reposition in a predetermined angle of 15° knee flexion. The measurements were applied using a conventional goniometer to both amputated and healthy knees. The last ones were used as internal control. All patients performed an active knee flexion from hyperextension to 15° in a closed kinetic chain in order to evaluate proprioceptive sensation of the knee joint using the joint position sense (JPS method during specific controllable circumstances very close to normal gait. Results. JPS at 15° flexion for the amputated knee was calculated to be equal to 13.91 (SD = ±4.74, and for the healthy side it was equal to 14.15 (SD = ±2.61. No statistically significant differences were detected between the amputated and the healthy limb (. Conclusions. The proprioceptive information of the stumps did not appear to be affected significantly after thigh amputation and application of artificial prosthesis when JPS at 15° was evaluated. It seems that these patients compensate the loss of the knee sensory receptors via alternative mechanisms.

  13. Knee Joint Optimization Design of Intelligent Bionic Leg Based on Genetic Algorithm

    Hualong Xie

    2014-09-01

    Full Text Available Intelligent bionic leg (IBL is an advanced prosthesis which can maximum functionally simulate and approach the motion trajectory of human leg. Knee joint is the most important bone of human leg and its bionic design has great significance to prosthesis performance. The structural components of IBL are introduced and virtual prototype is given. The advantages of 4-bar knee joint are analyzed and are adopted in IBL design. The kinematics model of 4-bar knee joint is established. The objective function, constraint condition, parameters selection and setting of genetic algorithm are discussed in detail. Based on genetic algorithm, the optimization design of IBL knee joint is done. The optimization results indicate that the 4-bar mechanism can achieve better anthropomorphic characteristics of human knee joint.

  14. Quasi-stiffness of the knee joint in flexion and extension during the golf swing.

    Choi, Ahnryul; Sim, Taeyong; Mun, Joung Hwan

    2015-01-01

    Biomechanical understanding of the knee joint during a golf swing is essential to improve performance and prevent injury. In this study, we quantified the flexion/extension angle and moment as the primary knee movement, and evaluated quasi-stiffness represented by moment-angle coupling in the knee joint. Eighteen skilled and 23 unskilled golfers participated in this study. Six infrared cameras and two force platforms were used to record a swing motion. The anatomical angle and moment were calculated from kinematic and kinetic models, and quasi-stiffness of the knee joint was determined as an instantaneous slope of moment-angle curves. The lead knee of the skilled group had decreased resistance duration compared with the unskilled group (P golf swing and developing rehabilitation strategies following surgery. PMID:25651162

  15. Rotationplasty for patients with osteosarcoma around the knee joint.

    Kawai,Akira

    1995-08-01

    Full Text Available The results of rotationplasty for patients with osteosarcoma around the knee joint are presented. After an average observation period of 13.3 months, there has been no local recurrence or metastasis. The ankle joints (the new knee joints of the patients were able to support their body weight with an average range of motion of 75 degrees. All patients could walk well without crutches and without risk of the giving way phenomenon. The average rate of the functional evaluation according to the re-modified system by Enneking was 84.5% (range, 80.0-86.7%. No patient had psychological trouble in accepting the shortened and rotated extremity. The results show that rotationplasty is a useful reconstructive method for the treatment of osteosarcoma around the knee joint.

  16. Differences between questionnaire-and interview-based measures of activities of daily living (ADL) ability and their association with observed ADL ability in women with rheumatoid arthritis, knee osteoarthritis, and fibromyalgia

    Wæhrens, E. E.; Bliddal, Henning; Danneskiold-Samsøe, Bente;

    2012-01-01

    Although self-report based on questionnaire is the common method to obtain information about activities of daily living (ADL) ability in rheumatic diseases, little is known about the relationship between measures of ADL ability based on questionnaire, interview, and observation. The present study...... examined whether measures of self-reported ADL ability based on questionnaire and interview yielded different results, determined whether the magnitude of the difference varied among women with rheumatoid arthritis (RA), knee osteoarthritis (OA), and fibromyalgia (FM), and investigated the relationships...

  17. Stress changes of lateral collateral ligament at different knee flexion with or without displaced movements: a 3-dimensional finite element analysis

    ZHONG Yan-lin; WANG You; WANG Hai-peng; RONG Ke; XIE Le

    2011-01-01

    Objective: To create a 3-dimensional finite element model of knee ligaments and to analyse the stress changes of lateral collateral ligament (LCL) with or without displaced movements at different knee flexion conditions.Methods: A four-major-ligament contained knee specimen from an adult died of skull injury was prepared for CT scanning with the detectable ligament insertion footprints,locations and orientations precisely marked in advance. The CT scanning images were converted to a 3-dimensional model of the knee with the 3-dimensional reconstruction technique and transformed into finite element model by the software of ANSYS. The model was validated using experimental and numerical results obtained by other scientists.The natural stress changes of LCL at five different knee flexion angles (0°, 30°, 60°, 90°, 120°) and under various motions of anterior-posterior tibial translation, tibial varus rotation and internal-external tibial rotation were measured.Results: The maximum stress reached to 87%-113%versus natural stress in varus motion at early 30° of knee flexions. The stress values were smaller than the peak value of natural stress at 0° (knee full extension) when knee bending was over 60° of flexion in anterior-posterior tibial translation and internal-external rotation.Conclusion: LCL is vulnerable to varus motion in almost all knee bending positions and susceptible to anterlor-posterior tibial translation or internal-external rotation at early 30° of knee flexions.

  18. Knee Pain and the Weekend Warriors

    Full Text Available ... knees to allow these knees to do their job. These knees carry sometimes ten times body weight, ... that block in, and he does a great job with these blocks, we work together, at least ...

  19. Arthritic Pain Relief through Partial Knee Replacement

    Full Text Available ... to a full knee replacement, what are the risks of stiffness with a partial knee replacement? Yeah, also known as arthrofibrosis for the doctors out there, knee surgery has a very - on average a pretty high ...

  20. Pain trajectory groups in persons with, or at high risk of, knee osteoarthritis: findings from the Knee Clinical Assessment Study and the Osteoarthritis Initiative

    Nicholls, E.; Thomas, E.; van der Windt, D.A.; Croft, P. R.; Peat, G

    2014-01-01

    Summary Objective The authors aimed to characterize distinct trajectories of knee pain in adults who had, or were at high risk of, knee osteoarthritis using data from two population-based cohorts. Method Latent class growth analysis was applied to measures of knee pain severity on activity obtained at 18-month intervals for up to 6 years between 2002 and 2009 from symptomatic participants aged over 50 years in the Knee Clinical Assessment Study (CAS-K) in the United Kingdom. The optimum laten...

  1. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football

    Clausen, M. B.; Tang, L.; Zebis, M. K.;

    2016-01-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to...... investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15–18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS...... injury in adolescent female football....

  2. Mind-Body Therapies and Osteoarthritis of the Knee

    Selfe, Terry Kit; Innes, Kim E.

    2009-01-01

    Osteoarthritis of the knee is a major cause of disability among adults worldwide. Important treatment options include nonpharmacologic therapies, and especially symptom management strategies in which patients take an active role. Among these, mind-body therapies may have particular promise for alleviating the distressful symptoms associated with osteoarthritis of the knee. However, systematic reviews are lacking. The objective of this paper is to review English-language articles describing cl...

  3. Nursing care by children with arthroscopy of the knee joint.

    ŠESTÁKOVÁ, Růžena

    2012-01-01

    With the increasing sports and physical activity pursued by young people, the spectrum of the knee joint injuries is extending. At the present time, arthroscopy represents one of the basic diagnostic and therapeutic methods in the case of the knee joint injuries. Owing to this method, the attending physician can examine the joint directly using the endoscopic instrument and they can possibly execute surgical treatment thereof as well. Thanks to development, this method can be applied in child...

  4. Diagnosis and Management of Acute Knee Ligament Injuries

    Hastings, David E.

    1990-01-01

    Knee ligament injuries are a common problem, especially in the athletic age group. The most common knee ligament injury is the so-called isolated anterior cruciate ligament tear. This is also the injury most likely to be missed. Isolated collateral ligament tears are generally managed non-operatively, but combined collateral and cruciate tears should be surgically repaired. “Isolated” anterior cruciate tears are generally repaired in the younger active athlete but are managed by hamstring exe...

  5. Modelling and Simulation of the Knee Joint with a Depth Sensor Camera for Prosthetics and Movement Rehabilitation

    Risto, S.; Kallergi, M.

    2015-09-01

    The purpose of this project was to model and simulate the knee joint. A computer model of the knee joint was first created, which was controlled by Microsoft's Kinect for Windows. Kinect created a depth map of the knee and lower leg motion independent of lighting conditions through an infrared sensor. A combination of open source software such as Blender, Python, Kinect SDK and NI_Mate were implemented for the creation and control of the simulated knee based on movements of a live physical model. A physical size model of the knee and lower leg was also created, the movement of which was controlled remotely by the computer model and Kinect. The real time communication of the model and the robotic knee was achieved through programming in Python and Arduino language. The result of this study showed that Kinect in the modelling of human kinematics and can play a significant role in the development of prosthetics and other assistive technologies.

  6. The Effects of a Valgus Collapse Knee Position on In Vivo ACL Elongation

    Utturkar, G. M.; Irribarra, L.A.; Taylor, K A; Spritzer, C.E.; Taylor, D. C.; Garrett, W E; DeFrate, Louis E.

    2012-01-01

    There are conflicting data regarding what motions increase ACL injury risk. More specifically, the mechanical role of valgus collapse positions during ACL injury remains controversial. Our objective was to evaluate ACL elongation in a model that mimics knee movements thought to occur during ACL injury. Eight healthy male subjects were imaged using MR and biplanar fluoroscopy to measure the in vivo elongation of the ACL and its functional bundles during three static knee positions: full extens...

  7. Differences in tibiofemoral kinematics between the unloaded robotic passive path and a weightbearing knee simulator

    Markus Wünschel

    2012-01-01

    Full Text Available Cadaveric in vitro studies are essential to test hypotheses concerning surgical manipulations in the same individual. Robotic technologies as well as different knee-models have been developed to get an in-depth comprehension of knee joint kinematics. The purpose of this study was to compare utilization of these different established principles. Ten human cadaveric knee specimens were used to measure the kinematics during a weight-bearing flexion in a 6-degrees-of-freedom knee simulator. While flexing the knee, joint quadriceps muscle forces were dynamically simulated to reach a vertical ground reaction force of 100N. Fourteen knee specimens were mounted in 6-degrees-of-freedom robotic manipulator with a universal force sensor. The unloaded flexing motion of each specimen was measured by finding positions for each degree of flexion where all forces are minimal (passive path. The kinematic data of the kneesimulator and the robot concerning internal-external rotation, anterior-posterior translation, varus-valgus motion, and medial-lateral translation was examined. For all investigated degrees of freedom the kinematics of the robotic passive path differed from the loaded kinematics in the knee simulator. Simulated bodyweight as well as the examination method used has a substantial influence on joint kinematics during flexion which has to be considered when interpreting biomechanical studies as well as clinical tests.

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

    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...... there is an increase in threshold to detection of a passive motion in knees and elbows for patients with knee OA. This indicates that OA may be associated with a generalized defect in proprioception with possible implications for the pathogenesis of the joint degeneration....

  9. Multiligamentous injuries and knee dislocations.

    Gimber, Lana H; Scalcione, Luke R; Rowan, Andrew; Hardy, Jolene C; Melville, David M; Taljanovic, Mihra S

    2015-11-01

    Complex capsular ligamentous structures contribute to stability of the knee joint. Simultaneous injury of two or more knee ligaments, aside from concurrent tears involving the anterior cruciate and medial collateral ligaments, is considered to be associated with femorotibial knee dislocations. Proximal tibiofibular joint dislocations are not always easily recognized and may be overlooked or missed. Patellofemoral dislocations can be transient with MR imaging sometimes required to reach the diagnosis. In this article, the authors describe the mechanism of injury, ligamentous disruptions, imaging, and treatment options of various types of knee dislocations including injuries of the femorotibial, proximal tibiofibular, and patellofemoral joints. PMID:26002747

  10. Experimentally reduced hip abductor function during walking: Implications for knee joint loads

    Henriksen, Marius; Aaboe, Jens; Simonsen, Erik B; Alkjaer, Tine; Bliddal, Henning

    2009-01-01

    -dimensional trunk and lower extremity joint kinematics and kinetics. Surface electromyography (EMG) of the glutei, quadriceps, and hamstring muscles were also measured. The peak GM EMG activity had temporal concurrence with peaks in frontal plane moments at both hip and knee joints. The EMG activity in the GM...... muscle was significantly reduced by pain (-39.6%). All other muscles were unaffected. Peaks in the frontal plane hip and knee joint moments were significantly reduced during pain (-6.4% and -4.2%, respectively). Lateral trunk lean angles and midstance hip joint adduction and knee joint extension angles...... loads at the knee joint during level walking....

  11. Treatment of persistent knee effusions with Yttrium 90

    Yttrium 90 intra-articular injection is used in persisting active joint of the knee, where medication has failed to resolve chronic inflammation. The effective dose delivered to the synovia is linked to Y 90 activity and depends on the size of the joint space, the synovial structure and thickness and the inflammatory activity of the synovitis. The amount of the injected activity of Y90 was estimated according the volume effusion in 28 pathologic knee of 18 patients aged 18 years and more (mean age 46 years). All patients have persistent knee effusions and most of them have rheumatoid arthritis but others had ankylosing spondylitis, Behcet disease, psoriatic arthritis. According the radiological classification of Steinbrocker, 19 pathological knees were in stage 1, 5 in stage 2 and 4 in stage 3. The mean value of the monthly removed volume of the synovial liquid from the pathological knee was determined during the last month preceding the radiosynoviorthesis and four groups were identified: V0 no evidence of effusion liquid, 0 ml100ml. The activity of Y 90 was estimated in order to obtain a total of 100 Gray in the envelope of 3 spherical phantoms with the same range of volume as defined above. The lowest activity of Y90, 111 MBq (3mCi) was determined for V0 according a mean value of standard sizes of knees. An activity of 18 MBq (0.5mCi) was added for each stage of 50 ml, so 129 MBq (3.5 mCi) for G1, 148 MBq (4 mCi) for G2 and 166 MBq (4.5 mCi) for G3. Efficacy of Y90 treatment was clinically assessed in all patients according to three parameters: pain, hydrarthrosis and range of joint movement at 1, 3, 6 and 12 months. The results were excellent in 13 knees and good in 9 and for most of them the efficacy of Y 90 was observed after 6 months. The results were less good in 3 knees but with an initial good evolution for all at 1 month. For 4 knees, the efficacy of Y 90 was bad. Although the small number of patients, these results show a high rate, 75%, of successful

  12. Selectively Lockable Knee Brace

    Myers, W. Neill (Inventor); Shadoan, Michael D. (Inventor); Forbes, John C. (Inventor); Baker, Kevin J. (Inventor); Rice, Darron C. (Inventor)

    1996-01-01

    A knee brace for aiding in rehabilitation of damaged leg muscles includes upper and lower housings normally pivotable one relative to the other about the knee joint axis of a patient. The upper housing is attachable to the thigh of the patient above the knee joint while the lower housing is secured to a stirrup which extends downwardly along the patient's leg and is attached to the patient's shoe. An actuation rod is carried within the lower housing and is coupled to a cable. The upper and lower housings carry cooperative clutch/brake elements which normally are disengaged to permit relative movement between the upper and lower housings. When the cable is extended the clutch/brake elements engage and lock the housings together. A heel strike mechanism fastened to the stirrup and the heel of the shoe is connected to the cable to selectively extend the cable and lock the brace in substantially any position when the patient places weight on the heel.

  13. An acoustic startle alters knee joint stiffness and neuromuscular control.

    DeAngelis, A I; Needle, A R; Kaminski, T W; Royer, T R; Knight, C A; Swanik, C B

    2015-08-01

    Growing evidence suggests that the nervous system contributes to non-contact knee ligament injury, but limited evidence has measured the effect of extrinsic events on joint stability. Following unanticipated events, the startle reflex leads to universal stiffening of the limbs, but no studies have investigated how an acoustic startle influences knee stiffness and muscle activation during a dynamic knee perturbation. Thirty-six individuals were tested for knee stiffness and muscle activation of the quadriceps and hamstrings. Subjects were seated and instructed to resist a 40-degree knee flexion perturbation from a relaxed state. During some trials, an acoustic startle (50 ms, 1000 Hz, 100 dB) was applied 100 ms prior to the perturbation. Knee stiffness, muscle amplitude, and timing were quantified across time, muscle, and startle conditions. The acoustic startle increased short-range (no startle: 0.044 ± 0.011 N·m/deg/kg; average startle: 0.047 ± 0.01 N·m/deg/kg) and total knee stiffness (no startle: 0.036 ± 0.01 N·m/deg/kg; first startle 0.027 ± 0.02 N·m/deg/kg). Additionally, the startle contributed to decreased [vastus medialis (VM): 13.76 ± 33.6%; vastus lateralis (VL): 6.72 ± 37.4%] but earlier (VM: 0.133 ± 0.17 s; VL: 0.124 ± 0.17 s) activation of the quadriceps muscles. The results of this study indicate that the startle response can significantly disrupt knee stiffness regulation required to maintain joint stability. Further studies should explore the role of unanticipated events on unintentional injury. PMID:25212407

  14. Three statistical experimental designs for enhancing yield of active compounds from herbal medicines and anti motion sickness bioactivity

    Yan Chen

    2015-01-01

    Full Text Available Background: Since antiquity, Zingiber officinale (ginger, pogostemonis herba, and radix aucklandiae have been used as traditional Chinese medicines to remit gastrointestinal discomfort. Recent evidences also show the efficacy of the three herbal medicines against nausea and vomiting. Objective: To optimize the CO2 supercritical fluid extraction (SFE CO2 conditions for ginger and the ethanol reflux extraction conditions for radix aucklandiae, control the quality of pogostemonis herba essential oil, and evaluate anti motion sickness activity of the compound recipes composed of the three herbal medicine extracts. Materials and Methods: Two orthogonal array designs L9 (34 were employed to optimize the SFE CO2 conditions for enhancing yield of 6 gingerol from ginger and the ethanol reflux extraction conditions for enhancing yield of costunolide and dehydrocostus lactone from radix aucklandiae; a uniform design U5(53 was applied for evaluation of anti motion sickness activity of the compound recipes. Results: Extraction pressure (P < 0.01, extraction temperature and extraction time (P < 0.05 have significant effects on the yield of 6 gingerol from ginger by SFE CO2; ethanol concentration (P < 0.01 and times of repeating extraction (P < 0.05 have significant effects on the total yield of costunolide and dehydrocostus lactone from radix aucklandiae by ethanol reflux extraction; the anti motion sickness effects of the optimized compound recipe composed of the three herbal medicine extracts were markedly better than those of dimenhydrinate. Conclusion: The compound recipe composed of ginger, pogostemonis herba, and radix aucklandiae could be developed as a promising anti motion sickness medicine.

  15. Random Motion with Interfacial Contact: Driven Diffusion vis-a-vis Mechanical Activation

    Goohpattader, P. S.; Chaudhury, M. K.

    2012-01-01

    Rolling of a small sphere on a solid support is governed by a non-linear friction that is akin to the Coulombic dry fiction. No motion occurs when the external field is weaker than the frictional resistance. However, with the intervention of an external noise, a viscous friction like property emerges; thus the sphere rolls with an uniform drift velocity that is proportional to the applied field. As the sphere rolls, it rocks forward and backward resulting in substantial fluctuation of displac...

  16. The Solar Activity Cycle is Weakly Synchronized with the Solar Inertial Motion

    Paluš, Milan; Kurths, J.; Schwarz, U.; Seehafer, N.; Novotná, Dagmar; Charvátová, Ivanka

    2007-01-01

    Roč. 365, č. 5-6 (2007), s. 421-428. ISSN 0375-9601 R&D Projects: GA AV ČR IAA3042401; GA AV ČR(CZ) IAA300120608 Institutional research plan: CEZ:AV0Z10300504; CEZ:AV0Z30420517; CEZ:AV0Z30120515 Keywords : sunspot cycle * phase synchronization * solar inertial motion * hypothesis testing * surrogate data Subject RIV: DG - Athmosphere Sciences, Meteorology Impact factor: 1.711, year: 2007

  17. A Combined Experimental and Computational Approach to Subject-Specific Analysis of Knee Joint Laxity.

    Harris, Michael D; Cyr, Adam J; Ali, Azhar A; Fitzpatrick, Clare K; Rullkoetter, Paul J; Maletsky, Lorin P; Shelburne, Kevin B

    2016-08-01

    Modeling complex knee biomechanics is a continual challenge, which has resulted in many models of varying levels of quality, complexity, and validation. Beyond modeling healthy knees, accurately mimicking pathologic knee mechanics, such as after cruciate rupture or meniscectomy, is difficult. Experimental tests of knee laxity can provide important information about ligament engagement and overall contributions to knee stability for development of subject-specific models to accurately simulate knee motion and loading. Our objective was to provide combined experimental tests and finite-element (FE) models of natural knee laxity that are subject-specific, have one-to-one experiment to model calibration, simulate ligament engagement in agreement with literature, and are adaptable for a variety of biomechanical investigations (e.g., cartilage contact, ligament strain, in vivo kinematics). Calibration involved perturbing ligament stiffness, initial ligament strain, and attachment location until model-predicted kinematics and ligament engagement matched experimental reports. Errors between model-predicted and experimental kinematics averaged attention to the need to verify that ligament engagement is in good general agreement with literature. To facilitate further investigations of subject-specific or population based knee joint biomechanics, data collected during the experimental and modeling phases of this study are available for download by the research community. PMID:27306137

  18. Minimal Feature Set for Unsupervised Classification of Knee MR Images

    Rajneet Kaur

    2011-11-01

    Full Text Available Knee scans is very useful and effective technique to detect the knee joint defects. Unsupervised Classification is useful in the absence of domain expert. Real Knee Magnetic Resonance Images have been collected from the MRI centres. Segmentation is implemented using Active Contour without Edges. DICOM, Haralick and some Statistical features have been extracted out. A database file of 704 images with 46 features per images has been prepared. Unsupervised Classification is implemented with clustering using EM model and then classification using different classifiers. Learning rate of 5 classifiers (ID3, J48, FID3new, Naive Bayes, and Kstar has been calculated. At the obtained learning rate minimal feature set has been obtained for unsupervised classification of Knee MR Images.

  19. Moxibustion for treating knee osteoarthritis: study protocol of a multicentre randomised controlled trial

    Lee, Seunghoon; Kim, Kun Hyung; Kim, Tae-Hun; Kim, Jung-Eun; Kim, Joo-Hee; Kang, Jung Won; Kang, Kyung-Won; Jung, So-Young; Kim, Ae-Ran; Park, Hyo-Ju; Shin, Mi-Suk; Hong, Kwon-Eui; Song, Ho-Sueb; Choi, Jin-Bong; Kim, Hyung-Jun

    2013-01-01

    Background The treatment of knee osteoarthritis, which is a major cause of disability among the elderly, is typically selected from multidisciplinary options, including complementary and alternative medicine. Moxibustion has been used in the treatment of knee osteoarthritis in Korea to reduce pain and improve physical activity. However, there is no sufficient evidence of its effectiveness, and it cannot therefore be widely recommended for treating knee osteoarthritis. We designed a randomised...

  20. Dynamic knee stability after anterior cruciate ligament injury : Emphasis on rehabilitation

    Tagesson (Sonesson), Sofi

    2008-01-01

    Anterior cruciate ligament injury leads to increased sagittal tibial translation, and perceptions of instability and low confidence in the knee joint are common. Many patients have remaining problems despite treatment and are forced to lower their activity level and prematurely end their career in sports. The effect of ACL reconstruction and/or rehabilitation on dynamic knee stability is not completely understood. The overall aim of this thesis was to study the dynamic knee stability during a...

  1. Diagnostic criterial to differentiate medial meniscal injury from degenerative changes on {sup 99m}Tc-MDP knee SPECT in patients with chronic knee pain

    Paeng, Jin Chul; Chung, June Key; Kang, Won Jun; So, Young; Lee, Dong Soo; Lee, Myung Chul [Seoul National University College of Medicine, Seoul (Korea, Republic of); Yoo, Jae Ho; Lee, Myung Chul [Seoul National University Nuclear Medicine, Seoul (Korea, Republic of); Jeong, Hwan Jeong [Wonkwang University College of Medicine, Iksan (Korea, Republic of)

    2003-04-01

    In patients with chronic knee pain, the diagnostic performance of {sup 99m}Tc-MDP knee SPECT for internal derangement of knee is deteriorated due to degenerative changes. In this study, we tried to establish diagnostic criteria to differentiate medial meniscal injury (MMI) from degenerative change (DC) when the uptake in increased in medial compartment. A total of 49 knee SPECT of the patients with chronic(more than 3 months) knee pain, which showed increased {sup 99m}Tc-MDP uptake in the medial compartment, were included in this study. The diagnosis was confirmed by arthroscopy. On knee SPECT, 3 diagnosic criteria for MMI were investigated. In Criterion, I, MMI was diagnosed when crescentic uptake was observed in the medial tibial plateau. In Criterion II, crescentic uptake was further classified into anterior, mid, posterior, and diffuse patterns, according to the location of maximal uptake; and only crescentic mid, posterior, and diffuse patterns were diagnosed as MMI. In Criterion III, MMI was diagnosed when medial tibial plateau showed higher activity then medial femoral condyle. The diagnostic performance of the 3 criteria was compared. The sensitivity and specificity were 93% and 14% in Criterion I, 89% and 38% in Criterion II, and 75% and 67% in Criterion III, respectively. Criterion III had significantly improve diagnostic performance, especially, specificity. In this study, we established a practical diagnostic criterion to differentiate MMI from DC on knee SPECT. The result is helpful to improve the diagnostic value of knee SPECT as a screening test for chronic knee pain.

  2. Diagnostic criterial to differentiate medial meniscal injury from degenerative changes on 99mTc-MDP knee SPECT in patients with chronic knee pain

    In patients with chronic knee pain, the diagnostic performance of 99mTc-MDP knee SPECT for internal derangement of knee is deteriorated due to degenerative changes. In this study, we tried to establish diagnostic criteria to differentiate medial meniscal injury (MMI) from degenerative change (DC) when the uptake in increased in medial compartment. A total of 49 knee SPECT of the patients with chronic(more than 3 months) knee pain, which showed increased 99mTc-MDP uptake in the medial compartment, were included in this study. The diagnosis was confirmed by arthroscopy. On knee SPECT, 3 diagnosic criteria for MMI were investigated. In Criterion, I, MMI was diagnosed when crescentic uptake was observed in the medial tibial plateau. In Criterion II, crescentic uptake was further classified into anterior, mid, posterior, and diffuse patterns, according to the location of maximal uptake; and only crescentic mid, posterior, and diffuse patterns were diagnosed as MMI. In Criterion III, MMI was diagnosed when medial tibial plateau showed higher activity then medial femoral condyle. The diagnostic performance of the 3 criteria was compared. The sensitivity and specificity were 93% and 14% in Criterion I, 89% and 38% in Criterion II, and 75% and 67% in Criterion III, respectively. Criterion III had significantly improve diagnostic performance, especially, specificity. In this study, we established a practical diagnostic criterion to differentiate MMI from DC on knee SPECT. The result is helpful to improve the diagnostic value of knee SPECT as a screening test for chronic knee pain

  3. Using motion-sensor camera technology to infer seasonal activity and thermal niche of the desert tortoise (Gopherus agassizii)

    Agha, Mickey; Augustine, Benjamin; Lovich, Jeffrey E.; Delaney, David F.; Sinervo, Barry; Murphy, Mason O.; Ennen, Joshua R.; Briggs, Jessica R.; Cooper, Robert J.; Price, Steven J.

    2015-01-01

    Understanding the relationships between environmental variables and wildlife activity is an important part of effective management. The desert tortoise (Gopherus agassizii), an imperiled species of arid environments in the southwest US, may have increasingly restricted windows for activity due to current warming trends. In summer 2013, we deployed 48 motion sensor cameras at the entrances of tortoise burrows to investigate the effects of temperature, sex, and day of the year on the activity of desert tortoises. Using generalized estimating equations, we found that the relative probability of activity was associated with temperature (linear and quadratic), sex, and day of the year. Sex effects showed that male tortoises are generally more active than female tortoises. Temperature had a quadratic effect, indicating that tortoise activity was heightened at a range of temperatures. In addition, we found significant support for interactions between sex and day of the year, and sex and temperature as predictors of the probability of activity. Using our models, we were able to estimate air temperatures and times (days and hours) that were associated with maximum activity during the study. Because tortoise activity is constrained by environmental conditions such as temperature, it is increasingly vital to conduct studies on how tortoises vary their activity throughout the Sonoran Desert to better understand the effects of a changing climate.

  4. Secondary Knee Osteoarthritis due to Neurofibromatosis Type 1 Treated with above the Knee Amputation: A Case Report

    Jay Patel

    2013-01-01

    Full Text Available Background. Neurofibromatosis Type 1 (NF-1 has a variety of associated orthopaedic manifestations that have been previously reported. We report a case of severe, grade 4 knee osteoarthritis (OA with recurrent subluxation and joint laxity due to multiple extra-articular neurofibromas ultimately treated with Above the Knee Amputation (AKA. Case Description. A 39-year-old man presented with multiple neurofibromas and lymphedema leading to degenerative changes of the knee. Conservative treatment failed due to the severity of the knee degeneration and patient discomfort. Likewise, arthroplasty was not possible due to poor bone quality and joint instability. Therefore, AKA was selected to relieve symptoms and provide functional improvement. six months after the procedure the patient has increased functional capacity for ambulation and activities of daily living, as well as significant decrease in pain and discomfort. Clinical Relevance. Extra-articular neurofibromas causing severe secondary OA in relatively young patients can be functionally improved with AKA and prosthetic device use.

  5. Magnification bone scan of knees for knee pain evaluation

    Knee pain is one of the common complaints of patients seen in our orthopedic clinic. Routine anterior and posterior views of whole body bone scan (WBBS) is often not sufficient in the evaluation of these patients. An ideal bone scan using pinhole collimator or single photon emission tomography (SPECT), however, is impractical and time consuming in busy nuclear medicine department with limited resources. Therefore, the aim of the study is to assess limited bone scan of knees with magnification (LNSKM) for knee pain evaluation. Technical aspect of LBSKM and diagnostic efficacy are discussed on this poster. Adult patients with knee pain were reffered for LBSKM from an orthopedic surgen specializing knees. Four hundred fifteen LBSKMs were performed since 1999. patients were given 740 MBq (20mCi) Tc-99m MDP intravenously and 3 hours later LBSKM was performed using a low energy high resolution parallel hole collimator and Siemens Orbitor camera. (Simens medical systems. Inc., Hoffman Estates, III., USA). Anterior view of the knees was taken for 5 min, without magnification and both lateral views of symptomatic knees were obtained with electronic magnification (1.25, upto 2.0) for 8 min each. Disease processes such as DJD, traumatic arthritis, P-F tendonitis, SONK, meniscus tear are detected and illustrated along with normal knee scan finding. We believe LBSKM may not be as good as SPECT or pinhole imaging of the knees in the evaluation of knee pain but superior to routine WBBS in the nuclear medicine department with limited resources of instrumentation and manpower

  6. Use of Transcutaneous Electrical Nerve Stimulation Device in Early Osteoarthritis of the Knee.

    Cherian, Jeffrey J; Kapadia, Bhaveen H; Bhave, Anil; McElroy, Mark J; Cherian, Christopher; Harwin, Steven F; Mont, Michael A

    2015-08-01

    Some have proposed the use of transcutaneous electrical nerve stimulation (TENS) as an adjunct to the current standard of care in treatment of osteoarthritis knee pain. The purpose of this study was to evaluate the effects of TENS on the following issues in patients who have early-stage osteoarthritis of the knee: (1) pain reduction; (2) subjective and (3) objective functional improvements; (4) quality-of-life (QOL) measure improvements; and (5) isokinetic strength. A prospective, randomized, and single-blinded trial was performed on 23 patients who were randomized to either novel TENS device or standard of care. Metrics analyzed included stair-climb test; timed-up-and-go test (TUGT); 2-minute walk test; 20 times, single leg 6-inch step test; five-repetition chair-rise test; active and passive range-of-motion (ROM) score; short form health survey-36 scores (SF-36) score; Knee Society Score (KSS); lower extremity functional scale (LEFS); visual analog scale (VAS); and isokinetic quadriceps and hamstring strength. In objective functional scores, TENS had significant improvements in TUGT and objective KSS when compared with the matching cohort. Subjective functional and QOL outcomes patients had a significant improvement of their LEFS and SF-36 physical component with the use of TENS brace. The TENS device significantly improved the quadriceps strength when compared with standard therapy. In evaluation for improvement within the TENS cohort, patients had a significant improvement at 3-month follow-up in the TUG test, timed stair-climb test, 20-times single leg, KSS, LEFS, and SF-36 physical component compared to their initial visit. In addition, within the TENS cohort, patients had a significant reduction in pain via VAS at their 3-month follow-up. In conclusion, the use of TENS for 3 months has shown encouraging results to improve pain, function, and QOL in patients with painful osteoarthritic knees, and could positively contribute as an adjunct to current

  7. Can a total knee arthroplasty be both rotationally unconstrained and anteroposteriorly stabilised?

    Imam, M. A.; Eifert, A.; Freeman, M. A. R.; Pinskerova, V.; Field, R. E.; Skinner, J.; Banks, S. A.

    2016-01-01

    Objectives Throughout the 20th Century, it has been postulated that the knee moves on the basis of a four-bar link mechanism composed of the cruciate ligaments, the femur and the tibia. As a consequence, the femur has been thought to roll back with flexion, and total knee arthroplasty (TKA) prostheses have been designed on this basis. Recent work, however, has proposed that at a position of between 0° and 120° the medial femoral condyle does not move anteroposteriorly whereas the lateral femoral condyle tends, but is not obliged, to roll back – a combination of movements which equates to tibial internal/ femoral external rotation with flexion. The aim of this paper was to assess if the articular geometry of the GMK Sphere TKA could recreate the natural knee movements in situ/in vivo. Methods The pattern of knee movement was studied in 15 patients (six male: nine female; one male with bilateral TKAs) with 16 GMK Sphere implants, at a mean age of 66 years (53 to 76) with a mean BMI of 30 kg/m2 (20 to 35). The motions of all 16 knees were observed using pulsed fluoroscopy during a number of weight-bearing and non-weight-bearing static and dynamic activities. Results During maximally flexed kneeling and lunging activities, the mean tibial internal rotation was 8° (standard deviation (sd) 6). At a mean 112° flexion (sd 16) during lunging, the medial and lateral condyles were a mean of 2 mm (sd 3) and 8 mm (sd 4) posterior to a transverse line passing through the centre of the medial tibial concavity. With a mean flexion of 117° (sd 14) during kneeling, the medial and lateral condyles were a mean of 1 mm (sd 4) anterior and 6 mm (sd 4) posterior to the same line. During dynamic stair and pivoting activities, there was a mean anteroposterior translation of 0 mm to 2 mm of the medial femoral condyle. Backward lateral condylar translation occurred and was linearly related to tibial rotation. Conclusion The GMK Sphere TKA in our study group shows movements similar in

  8. Motion or activity: their role in intra- and inter-subject variation in fMRI

    Lund, Torben E; Nørgaard, Minna D; Rostrup, Egill;

    2005-01-01

    word-generation tasks. Two of the subjects were examined 10 times on 10 different days using the same paradigms. We systematically investigated one approach of correcting for residual movement effects: the inclusion of regressors describing movement-related effects in the design matrix of a General...... 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....

  9. Treating Osteoarthritis of the Knee

    ... with an artificial joint made from metals and plastic. All or part of the knee joint may be replaced in this procedure. Although recovery may take a long time depending on the extent of your surgery, the results of arthroplasty are often successful. Knee ...

  10. Minimally Invasive Total Knee Arthroplasty

    Full Text Available ... female. The knee is a little -- I would grade it a one plus lax knee but it’s ... I do not see problems with loss of blood supply in my patella and I don't ... I don't have problems with losing my blood supply of this patella. So this lady measured ...

  11. Exercise and the Knee Joint.

    Clarke, H. Harrison, Ed.

    1976-01-01

    This report by the President's Council on Physical Fitness and Sports examines the effects of various forms of physical exercise on the knee joint which, because of its vulnerability, is especially subject to injury. Discussion centers around the physical characteristics of the joint, commonly used measurements for determining knee stability,…

  12. Minimally Invasive Total Knee Arthroplasty

    Full Text Available ... up the midline to come down into the knee joint. The nice thing about that is when we ... whole lot of their own valgus into the knee. And I feel that those, if you set them in slightly less valgus, will tend to end up with a more parallel joint line with the floor and hopefully a longer- ...

  13. Total Knee Replacement for Women

    Full Text Available ... Ken, here’s another question. “Do you utilize highly cross linked polyethylene for all your total knees or just in younger patients? I use the highly cross linked polyethylene in all the knees. I think ...

  14. Minimally Invasive Total Knee Arthroplasty

    Full Text Available ... brought to you by Zimmer. During the program, it’s easy for you to learn more about the ... The knee is a little -- I would grade it a one plus lax knee but it’s basically ...

  15. Comparison of Knee Proprioception Between Blind and Healthy Sportsmen

    Şilil, Mehtap Kaçmaz; Sargın, Serdar; Atik, Aziz; Meriç, Gökhan; Özer, Muhammet; Akseki, Devrim

    2014-01-01

    Objectives: Visual sense and proprioception have a big role in motion control. Visual communication ensures the data in proprioceptive period. The other senses of blind people are improved because of the lack of the visual ability but there are not enough data for the proprioceptive quality. The purpose of this study is to compare the knee joint proprioception of the blind and normal sportsmen and figure out the prorioceptive quality. Methods: 16 visually-challenged sportsmen (12 males and 4 ...

  16. Comparison of neuromuscular and quadriceps strengthening exercise in the treatment of varus malaligned knees with medial knee osteoarthritis: a randomised controlled trial protocol

    Bennell Kim L

    2011-12-01

    -reported physical function measured at baseline and immediately following the program. Secondary outcomes include the external knee adduction moment angular impulse, electromyographic muscle activation patterns, knee and hip muscle strength, balance, functional ability, and quality-of-life. Discussion The findings will help determine whether neuromuscular exercise is superior to traditional quadriceps strengthening regarding effects on knee load, pain and physical function in people with medial knee osteoarthritis and varus malalignment. Trial Registration Australian New Zealand Clinical Trials Registry reference: ACTRN12610000660088

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

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

    2010-01-01

    Walking with hiking poles has become a popular way of exercising. Walking with poles is advocated as a physical activity that significantly reduces the loading of the hip, knee and ankle joints. We have previously observed that pole walking does not lead to a reduction of the load on the knee joint....... However, it is unclear whether an increased force transmitted through the poles can reduce the load on the knee joint. Thus, the purpose of the present study was to investigate if an increased load transmitted through the arms to the poles could reduce the knee joint compression force during level walking...... with poles. We hypothesized that an increased pole force would result in a reduction of the knee joint compression force. Gait analyses from 10 healthy subjects walking with poles were obtained. The pole force was measured simultaneously during the gait analyses. The knee joint compression forces were...

  18. THE EFFECTS OF KNEE JOINT EFFUSION ON QUADRICEPS ELECTROMYOGRAPHY DURING JOGGING

    William I. Sterett

    2005-03-01

    Full Text Available To investigate and describe the influence of intra-articular effusion on knee joint kinematics and electromyographic (EMG profiles during jogging. Thirteen individuals underwent a 20 cc 0.9% saline insufflation of the knee joint capsule and completed 8 jogging trials. Stance phase, sagittal plane knee joint kinematics and thigh muscular EMG profiles were compared pre- and post-insufflation utilizing a paired t-test (p = 0.05. Mild knee effusion caused a reduction in vastus medialis (p = 0.005 and lateralis (p = 0.006 EMG activity. The rectus femoris, biceps femoris and medial hamstring muscles did not exhibit changes due to this protocol. There were no changes in the sagittal plane knee joint kinematic pattern. Twenty cc effusion can cause quadriceps inhibition in the vastus medialis and the vastus lateralis in otherwise healthy individuals during jogging. This study provides baseline data for the effects of mild knee joint effusion on thigh musculature during jogging.

  19. MR findings in knee osteoarthritis

    Knee osteoarthritis (OA) is a leading cause of disability. Recent advances in drug discovery techniques and improvements in understanding the pathophysiology of osteoarthritic disorders have resulted in an unprecedented number of new therapeutic agents. Of all imaging modalities, radiography has been the most widely used for the diagnosis and management of the progression of knee OA. Magnetic resonance imaging is a relatively recent technique and its applications to osteoarthritis have been limited. Compared with conventional radiography, MR imaging offers unparalleled discrimination among articular soft tissues by directly visualizing all components of the knee joint simultaneously and therefore allowing the knee joint to be evaluated as a whole organ. In this article we present the MR findings in knee OA including cartilage abnormalities, osteophytes, bone edema, subarticular cysts, bone attrition, meniscal tears, ligament abnormalities, synovial thickening, joint effusion, intra-articular loose bodies, and periarticular cysts. (orig.)

  20. REHABILITATION FOLLOWING KNEE DISLOCATION WITH LATERAL SIDE INJURY: IMPLEMENTATION OF THE KNEE SYMMETRY MODEL

    Kinzer, Angie; Jenkins, Walter; Urch, Scott E.; Shelbourne, K. Donald

    2010-01-01

    Rehabilitation following lateral side knee ligament repair or reconstruction has traditionally utilized a conservative approach. An article outlining a new concept in rehabilitation following ACL reconstruction called the Knee Symmetry Model was recently published13. The Knee Symmetry Model can also be applied to rehabilitation of other knee pathologies including a knee dislocation with a lateral side injury.

  1. Self-reported previous knee injury and low knee function increase knee injury risk in adolescent female football.

    Clausen, M B; Tang, L; Zebis, M K; Krustrup, P; Hölmich, P; Wedderkopp, N; Andersen, L L; Christensen, K B; Møller, M; Thorborg, K

    2016-08-01

    Knee injuries are common in adolescent female football. Self-reported previous knee injury and low Knee injury and Osteoarthritis Outcome Score (KOOS) are proposed to predict future knee injuries, but evidence regarding this in adolescent female football is scarce. The aim of this study was to investigate self-reported previous knee injury and low KOOS subscale score as risk factors for future knee injuries in adolescent female football. A sample of 326 adolescent female football players, aged 15-18, without knee injury at baseline, were included. Data on self-reported previous knee injury and KOOS questionnaires were collected at baseline. Time-loss knee injuries and football exposures were reported weekly by answers to standardized text-message questions, followed by injury telephone interviews. A priori, self-reported previous knee injury and low KOOS subscale scores (female football. PMID:26179111

  2. Dynamic gadolinium-enhanced magnetic resonance imaging allows accurate assessment of the synovial inflammatory activity in rheumatoid arthritis knee joints: a comparison with synovial histology

    Axelsen, Mette Bjørndal; Stoltenberg, M.; Poggenborg, R.; Kubassova, O.; Boesen, M.; Bliddal, H.; Hørslev-Petersen, K.; Hanson, Lars G.; Østergaard, M.

    2012-01-01

    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......) = 0.70, p = 0.001 and rho = 0.74, p = 0.001, respectively). Intraand inter-reader ICCs were very high (0.93-1.00). No Whole slice parameters were correlated to histology. Conclusion: DCE-MRI provides fast and accurate assessment of synovial inflammation in RA patients. Manual outlining of the joint to...

  3. Preliminary analysis of knee stress in Full Extension Landing

    Majid Davoodi Makinejad

    2013-09-01

    Full Text Available OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm, using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities.

  4. IN VIVO KINEMATICS OF THE ANTERIOR CRUCIATE LIGAMENT DEFICIENT KNEE DURING WIDE-BASED SQUAT USING A 2D/3D REGISTRATION TECHNIQUE

    Takeshi Miyaji

    2012-12-01

    Full Text Available Anterior cruciate ligament (ACL deficiency increases the risk of early osteoarthritis (OA. Studies of ACL deficient knee kinematics would be important to reveal the disease process and therefore to find mechanisms which would potentially slow OA progression. The purpose of this study was to determine if in vivo kinematics of the anterior cruciate ligament deficient (ACLD knee during a wide-based squat activity differ from kinematics of the contralateral intact knee. Thirty-three patients with a unilateral ACLD knee consented to participate in this institutional review board approved study with the contralateral intact knee serving as the control. In vivo knee kinematics during the wide-based squat were analyzed using a 2D/3D registration technique utilizing CT-based bone models and lateral fluoroscopy. Comparisons were performed using values between 0 and 100° flexion both in flexion and extension phases of the squat activity. Both the ACLD and intact knees demonstrated increasing tibial internal rotation with knee flexion, and no difference was observed in tibial rotation between the groups. The tibia in the ACLD knee was more anterior than that of the contralateral knees at 0 and 5° flexion in both phases (p < 0.05. Tibiofemoral medial contact points of the ACLD knees were more posterior than that of the contralateral knees at 5, 10 and 15° of knee flexion in the extension phase of the squat activity (p < 0.05. Tibiofemoral lateral contact points of the ACLD knees were more posterior than that of the contralateral knees at 0° flexion in the both phases (p < 0.05. The kinematics of the ACLD and contralateral intact knees were similar during the wide-based squat except at the low flexion angles. Therefore, we conclude the wide-based squat may be recommended for the ACLD knee by avoiding terminal extension

  5. Osteochondral Allograft Transplantation in the Knee.

    Zouzias, Ioannis C; Bugbee, William D

    2016-06-01

    The technique of osteochondral allograft (OCA) transplantation has been used to treat a wide spectrum of cartilage deficiencies in the knee. Its use has been supported by basic science and clinical studies that show it is a safe and effective treatment option. What sets fresh OCA transplantation apart from other cartilage procedures in the knee, is the ability to treat large defects with mature hyaline cartilage. Studies looking at transplantation of fresh OCAs in the general population have shown reliable pain relief and return to activities of daily living. Reports of cartilage injuries in athletes have risen over the years and more research is needed in evaluating the successfulness of OCA transplantation in the athletic population. PMID:27135291

  6. Residual force enhancement during multi-joint leg extensions at joint- angle configurations close to natural human motion.

    Paternoster, Florian Kurt; Seiberl, Wolfgang; Hahn, Daniel; Schwirtz, Ansgar

    2016-03-21

    The isometric steady-state forces following lengthening are greater than those produced at the same muscle length and activation level but without prior lengthening. Although residual force enhancement (RFE) has been investigated across a range of conditions, its relevance for daily human movement is still poorly understood. We aimed to study RFE in a setup imitating daily activity, i.e., submaximal activation of the lower extremity's muscles with slightly flexed knee joints comparable to human walking. A motor-driven leg press dynamometer was used for randomly arranged purely isometric and isometric-eccentric-isometric contractions. Thirteen subjects performed multi-joint leg extensions, which were feedback-controlled at 30% of maximum voluntary vastus lateralis activation. Isometric-eccentric-isometric contractions incorporated a stretch from 30° to 50° knee flexion, while isometric contractions were performed at 50° knee flexion. Isometric contractions following stretch and purely isometric reference contractions were performed at 50° knee flexion. Kinematics, forces, and muscular activity were measured using 3D optical motion tracking, force plates, and surface EMG of 9 lower limb muscles of the right leg and joint torques were calculated by inverse dynamics. Variables of standardization (EMG, joint angles) showed no differences between contraction conditions. Eight of 13 subjects showed RFE of up to 24.8±32.5% for external forces and joint torques. Because the remaining 5 non-responders failed to produce enhanced forces during the stretch, we believe that RFE is functionally relevant for muscle function comparable to everyday human motion but only if there is enhanced force during stretch that sufficiently triggers mechanisms underlying RFE. PMID:26903409

  7. Is There an Ideal Patellar Thickness Following Total Knee Arthroplasty?

    Pierce, Todd P; Jauregui, Julio J; Cherian, Jeffrey J; Elmallah, Randa K; Harwin, Steven F; Mont, Michael A

    2016-01-01

    Orthopedic surgeons resurface the patella during total knee arthroplasty to avoid complications such as pain, patello-femoral arthritis, and patellar maltracking and to reduce the risk for reoperation. However, many complications, such as decreased range of motion, increased fractures, and polyethylene wear, have been described with this procedure. One determinant when resurfacing a patella is the thickness of its cuts. This review aims to investigate the relationship between patellar thickness and outcome parameters such as range of motion, patient-reported outcomes, periprosthetic fractures, and reoperations. PMID:26726982

  8. Stochastic Noncircular Motion and Outflows Driven by Magnetic Activity in the Galactic Bulge Region

    Suzuki, Takeru K; Torii, Kazufumi; Machida, Mami; Matsumoto, Ryoji

    2015-01-01

    By performing a global magneto-hydrodynamical simulation for the Milky Way with an axisymmetric gravitational potential, we propose that spatially dependent amplification of magnetic fields possibly explains the observed noncircular motion of the gas in the Galactic center region. The radial distribution of the rotation frequency in the bulge region is not monotonic in general. The amplification of the magnetic field is enhanced in regions with stronger differential rotation, because magnetorotational instability and field-line stretching are more effective. The strength of the amplified magnetic field reaches >~ 0.5 mG, and radial flows of the gas are excited by the inhomogeneous transport of angular momentum through turbulent magnetic field that is amplified in a spatially dependent manner. In addition, the magnetic pressure-gradient force also drives radial flows in a similar manner. As a result, the simulated position-velocity diagram exhibits a time-dependent asymmetric parallelogram-shape owing to the i...

  9. Rheumatoid arthritis of the knee - radiological evaluation

    Rheumatoid arthritis is a chronic, multisystemic disease. The characteristic feature is persistent inflammatory synovitis. The knee joint is commonly involved with synovial hypertrophy, chronic effusion, and frequently ligamentous laxity. Pain and swelling behind the knee may be caused by extension of inflamed synovium into the popliteal space (Baker's cyst). Plain radiographs of the knee joint remain the basic radiological procedure, although early in the disease they might not provide significant changes. Sonography sufficiently reveals synovial fluid and Baker cysts, but cannot be recommended for evaluation of synovial proliferations or pannus formation. Computer tomography has only limited indications and may be used for the evaluation of subtle erosive lesions or the quantitation of osteoporotic changes. Magnetic resonance imaging has shown excellent visualization of cartilage, fluid, synovium and soft tissues and is the method of choice for the demonstration of early affection and the evaluation of panus activity and therapy control. With daministration of contrast agents (gadolinium), dynamic studies may demonstrate inflammatory activity. Modern MR sequences, such as T1 SE 'fat sat' or magnetization transfer, further improve the discrimination of cartilage, pannus and synovial fluid. (orig.)

  10. Prolonged Epidural Infusion Improves Functional Outcomes Following Knee Arthroscopy in Patients with Arthrofibrosis after Total Knee Arthroplasty: A Retrospective Evaluation.

    Saltzman, Bryan M; Dave, Ankur; Young, Adam; Ahuja, Mukesh; Amin, Sandeep D; Bush-Joseph, Charles A

    2016-01-01

    A total of 20 consecutive patients with knee stiffness post total knee arthroplasty (TKA) underwent arthroscopic lysis of adhesions and manipulation plus indwelling epidural were evaluated retrospectively. Epidural catheters were placed preoperatively for an intended 6 weeks of postoperative analgesia to facilitate intensive physical therapy. The mean loss of knee extension immediately before incision was 13.5 ± 9.1 degrees (range, 0-35 degrees) and flexion was 77.65 ± 19.2 degrees (range, 45-125 degrees). At the 6-week and final (mean, 0.47 years) follow-up, the loss of extension was 1.5 ± 5.1 degrees (range, -10 to +7 degrees) and 5.4 ± 4.7 degrees (range, 0-15 degrees), respectively, and flexion was 99.7 ± 12.3 degrees (range, 75-120 degrees) and 98.5 ± 16.1 degrees (range, 75-130 degrees), respectively. Of the 20 patients, 2 missed their 6-week clinic visit. Improvements in motion immediately preoperative to 6-week and final follow-up were each significant (p definition for clinical motion success and 70% maintained success at final follow-up. Visual analog scale improved significantly from 5.4 to 2.0 (p success postoperatively as measured by range of motion improvement. PMID:25300008

  11. Complexity reduction in the H.264/AVC using highly adaptive fast mode decision based on macroblock motion activity

    Abdellah, Skoudarli; Mokhtar, Nibouche; Amina, Serir

    2015-11-01

    The H.264/AVC video coding standard is used in a wide range of applications from video conferencing to high-definition television according to its high compression efficiency. This efficiency is mainly acquired from the newly allowed prediction schemes including variable block modes. However, these schemes require a high complexity to select the optimal mode. Consequently, complexity reduction in the H.264/AVC encoder has recently become a very challenging task in the video compression domain, especially when implementing the encoder in real-time applications. Fast mode decision algorithms play an important role in reducing the overall complexity of the encoder. In this paper, we propose an adaptive fast intermode algorithm based on motion activity, temporal stationarity, and spatial homogeneity. This algorithm predicts the motion activity of the current macroblock from its neighboring blocks and identifies temporal stationary regions and spatially homogeneous regions using adaptive threshold values based on content video features. Extensive experimental work has been done in high profile, and results show that the proposed source-coding algorithm effectively reduces the computational complexity by 53.18% on average compared with the reference software encoder, while maintaining the high-coding efficiency of H.264/AVC by incurring only 0.097 dB in total peak signal-to-noise ratio and 0.228% increment on the total bit rate.

  12. 膝部骨折术后的早期康复效果观察%Observation of Early Rehabilitation After Knee Fracture

    张耀武

    2014-01-01

    Objective To observe the fracture of the knee by early postoperative rehabilitation. Methods Selected admitted in our hospital in December 2009 to December 2012 during the fracture of the knee in patients with 104 cases, were randomly divided into control group and observation group. 51 cases of control group patients, rehabilitation treatment in patients with bone fracture stability; the observation group of 53 patients, rehabilitation treatment in second days after fracture operation. Comparing the two groups of patients with rehabilitation. Results In the control quality of motion of knee joint in patients with the excellent and good rate was 82.4%, investigate the quality of knee joint activity in patients with excellent and good rate was 96.2%, with statistical significance of quality of knee joint activities of two groups of patients the excellent and good rate difference(P<0.05). Conclusion For patients with knee fracture in the operation, early rehabilitation, contribute to the recovery of function of knee joint, the rehabilitation train of thought to have clinical application value.%目的:观察膝部骨折术后进行早期康复的效果。方法选取我院2009年12月至2012年12月期间收治的膝部骨折患者104例,随机分为对照组与观察组。对照组患者51例,在骨折患者骨位稳定后进行康复治疗;观察组患者53例,在骨折手术后第2天进行康复治疗。比较两组患者的康复效果。结果对照组患者的膝关节活动质量优良率为82.4%,观察组患者的膝关节活动质量优良率为96.2%,两组患者的膝关节活动质量优良率比较差异具有统计学意义(P<0.05)。结论对于膝部骨折患者,在手术后早期进行康复治疗,有助于膝关节功能的恢复,该康复思路具有在临床上应用的价值。

  13. Osteonecrosis of the knee: review

    Karim, Ammar R.; Cherian, Jeffrey J.; Jauregui, Julio J.; Pierce, Todd

    2015-01-01

    Osteonecrosis is a devastating disease that can lead to end-stage arthritis of various joint including the knee. There are three categories of osteonecrosis that affect the knee: spontaneous osteonecrosis of the knee (SONK), secondary, and post-arthroscopic. Regardless of osteonecrosis categories, the treatment of this disease aims to halt further progression or delay the onset of end-stage arthritis of the knee. However, once substantial joint surface collapse has occurred or there are sign of degenerative arthritis, joint arthroplasty is the most appropriate treatment option. Currently, the non-operative treatment options consist of observation, non-steroidal anti-inflammatory drugs (NSAIDs), protected weight bearing, and analgesia as needed. Operative interventions include joint preserving surgery, unilateral knee arthroplasty (UKA), or total knee arthroplasty (TKA) depending on the extent and type of disease. Joint preserving procedures (i.e., arthroscopy, core decompression, osteochondral autograft, and bone grafting) are usually attempted in pre-collapse and some post-collapse lesions, when the articular cartilage is generally intact with only the underlying subchondral bone being affected. Conversely, after severe subchondral collapse has occurred, procedures that attempt to salvage the joint are rarely successful and joint arthroplasty are necessary to relieve pain. The purpose of this article is to highlight the recent evidence concerning the treatment options across the spectrum of management of osteonecrosis of the knee including lesion observation, medications, joint preserving techniques, and total joint arthroplasties. PMID:25705638

  14. Identification of Flap Motion Parameters for Vibration Reduction in Helicopter Rotors with Multiple Active Trailing Edge Flaps

    Uğbreve;ur Dalli

    2011-01-01

    Full Text Available An active control method utilizing the multiple trailing edge flap configuration for rotorcraft vibration suppression and blade loads control is presented. A comprehensive model for rotor blade with active trailing edge flaps is used to calculate the vibration characteristics, natural frequencies and mode shapes of any complex composite helicopter rotor blade. A computer program is developed to calculate the system response, rotor blade root forces and moments under aerodynamic forcing conditions. Rotor blade system response is calculated using the proposed solution method and the developed program depending on any structural and aerodynamic properties of rotor blades, structural properties of trailing edge flaps and properties of trailing edge flap actuator inputs. Rotor blade loads are determined first on a nominal rotor blade without multiple active trailing edge flaps and then the effects of the active flap motions on the existing rotor blade loads are investigated. Multiple active trailing edge flaps are controlled by using open loop controllers to identify the effects of the actuator signal output properties such as frequency, amplitude and phase on the system response. Effects of using multiple trailing edge flaps on controlling rotor blade vibrations are investigated and some design criteria are determined for the design of trailing edge flap controller that will provide actuator signal outputs to minimize the rotor blade root loads. It is calculated that using the developed active trailing edge rotor blade model, helicopter rotor blade vibrations can be reduced up to 36% of the nominal rotor blade vibrations.

  15. Motion mitigation for lung cancer patients treated with active scanning proton therapy

    Grassberger, Clemens, E-mail: Grassberger.Clemens@mgh.harvard.edu [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 and Center for Proton Radiotherapy, Paul Scherrer Institute, Villigen-PSI 5232 (Switzerland); Dowdell, Stephen; Sharp, Greg; Paganetti, Harald [Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts 02114 (United States)

    2015-05-15

    Purpose: Motion interplay can affect the tumor dose in scanned proton beam therapy. This study assesses the ability of rescanning and gating to mitigate interplay effects during lung treatments. Methods: The treatments of five lung cancer patients [48 Gy(RBE)/4fx] with varying tumor size (21.1–82.3 cm{sup 3}) and motion amplitude (2.9–30.6 mm) were simulated employing 4D Monte Carlo. The authors investigated two spot sizes (σ ∼ 12 and ∼3 mm), three rescanning techniques (layered, volumetric, breath-sampled volumetric) and respiratory gating with a 30% duty cycle. Results: For 4/5 patients, layered rescanning 6/2 times (for the small/large spot size) maintains equivalent uniform dose within the target >98% for a single fraction. Breath sampling the timing of rescanning is ∼2 times more effective than the same number of continuous rescans. Volumetric rescanning is sensitive to synchronization effects, which was observed in 3/5 patients, though not for layered rescanning. For the large spot size, rescanning compared favorably with gating in terms of time requirements, i.e., 2x-rescanning is on average a factor ∼2.6 faster than gating for this scenario. For the small spot size however, 6x-rescanning takes on average 65% longer compared to gating. Rescanning has no effect on normal lung V{sub 20} and mean lung dose (MLD), though it reduces the maximum lung dose by on average 6.9 ± 2.4/16.7 ± 12.2 Gy(RBE) for the large and small spot sizes, respectively. Gating leads to a similar reduction in maximum dose and additionally reduces V{sub 20} and MLD. Breath-sampled rescanning is most successful in reducing the maximum dose to the normal lung. Conclusions: Both rescanning (2–6 times, depending on the beam size) as well as gating was able to mitigate interplay effects in the target for 4/5 patients studied. Layered rescanning is superior to volumetric rescanning, as the latter suffers from synchronization effects in 3/5 patients studied. Gating minimizes the

  16. Gait changes in patients with knee osteoarthritis are replicated by experimental knee pain

    Henriksen, Marius; Nielsen, Thomas Graven; Aaboe, Jens;

    2010-01-01

    Medial knee osteoarthritis (OA) is characterized by pain and associated with abnormal knee moments during walking. The relationship between knee OA pain and gait changes remains to be clarified, and a better understanding of this link could advance the treatment and prevention of disease...... progression. This study investigated changes in knee moments during walking following experimental knee pain in healthy volunteers, and whether these changes replicated the joint moments observed in medial knee OA patients....

  17. Flare activity, sunspot motions, and the evolution of vector magnetic fields in Hale region 17244

    Neidig, Donald F.; Hagyard, Mona J.; Machado, Marcos E.; Smith, Jesse B., Jr.

    1986-01-01

    The magnetic and dynamical circumstances leading to the 1B/M4 flare of November 5, 1980 are studied, and a strong association is found between the buildup of magnetic shear and the onset of flare activity within the active region. The development of shear, as observed directly in vector magnetograms, is consistent in detail with the dynamical history of the active region and identifies the precise location of the optical and hard-X-ray kernels of the flare emission.

  18. Using structure-from-motion for monitoring active lava flows and domes

    James, Mike R.; Robson, Stuart; Varley, Nick

    2016-04-01

    3-D reconstruction software based on structure-from-motion (SfM) algorithms can substantially reduce the requirements and learning curve for generating topographic data from photographs, and thus offers strong potential for data collection in many dynamic environments. Unfortunately, SfM-based software tends not to provide the rigorous metrics that are used to assess the quality of results in conventional photogrammetry software. Here, we use examples of repeat oblique airborne acquisitions from a volcanic dome (Volcán de Colima, Mexico) and terrestrial time-lapse stereo-photography (Mt. Etna, Sicily) to examine the sensitivity of results to imaging characteristics and SfM processing procedures. At Volcán de Colima, photographs were acquired with a relatively favourable convergent geometry, from an opened window in a light aircraft. However, hazards prevent the deployment of ground control, so the derived topographic shape relies entirely on the image tie points generated automatically by the software. In contrast, at Mt. Etna, control targets could be used but, with only two (mildly convergent) cameras, the image geometry is naturally weaker that at Colima. We use both of these cases to explore some of the challenges involved with understanding the error inherent in projects processed using SfM-based approaches. Results are compared with those achieved using a rigorous close-range photogrammetry package.

  19. Myocardial metabolism, perfusion, wall motion and electrical activity in Duchenne muscular dystrophy

    The cardiomyopathy of Duchenne's muscular dystrophy originates in the posterobasal left ventricle and extends chiefly to the contiguous lateral wall. Ultrastructural abnormalities in these regions precede connective tissue replacement. We postulated that a metabolic fault coincided with or antedated the subcellular abnormality. Accordingly, regional left ventricular metabolism, perfusion and wall motion were studied using positron computed tomography and metabolic isotopes supplemented by thallium perfusion scans, equilibrium radionuclide angiography and M-mode and two-dimensional echocardiography. To complete the assessment, electrocardiograms, vectorcardiograms, 24 hour taped electrocardiograms and chest x-rays were analyzed. Positron computed tomography utilizing F-18 2-fluoro 2-deoxyglucose (FDG) provided the first conclusive evidence supporting the hypothesis of a premorphologic regional metabolic fault. Thus, cardiac involvement in duchenne dystrophy emerges as a unique form of heart disease, genetically targeting specific regions of ventricular myocardium for initial metabolic and subcellular changes. Reported ultrastructural abnormalities of the impulse and conduction systems provide, at least in part, a basis for the clinically observed sinus node, intraatrial, internodal, AV nodal and infranodal disorders

  20. [Musculoskeletal disorders of the knee of workers].

    Caubet, Alain

    2009-11-20

    50% of workers have been or will be affected by knee pains and complaints will be more frequent as the population ages and careers will be longer. The increase in prevalence depends on mechanical or morphological causes as well as psychosocial state and work organization. Lesions of the meniscus, well known for a long time, seem to be stable in the statistics of Social Security as well as the hygroma; the use of knee-pads (overalls with built-in cushions) is strongly recommended while working in kneeling or squatting position, even DIY activities. Are particularly dangerous: the squatting or kneeling position extended for longer than one hour a day, often recovering from these two positions (more than 30 times a day), lifting or carrying heavy loads, often climbing (around 30 times per day) stairs or ladders. These gestures and postures are unavoidable in some jobs; in those cases, advices given by the specialist of occupational medicine and the ergonomist may improve or alter the habits of the worker or of his entire team. The prevention of overweight and the habit of carrying heavy loads must be amplified, for all the usual positions of work. Consulting to decide about the return to work after surgery for knee replacement will be more frequent. Then, as each time work can interfere with health, it is logical that the family doctor have (via the patient) links with the specialist of occupational medicine, which holds valuable information for quality of life of employees. PMID:19961084