Knee extension and flexion: MR delineation of normal and torn anterior cruciate ligaments

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Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru; Anno, Izumi; Itai, Yuji [Univ. of Tsukuba, Ibaraki (Japan)

1996-03-01

Our goal was to assess the effect of joint position of semiflexed and extended knees in MR delineation of the anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, the knee joint was either fully extended or bent to a semiflexed position (average 45{degrees} of flexion) within the magnet bore. Sets of oblique sagittal MR images were obtained for both extended and flexed knee positions. Thirty-two knees with intact ACLs and 43 knees with arthroscopically proven ACL tears were evaluated. Two observers compared paired MR images of both extended and flexed positions and rated them by a relative three point scale. Anatomic correlation in MR images was obtained by a cadaveric knee with incremental flexion. The MR images of flexed knees were more useful than of extended knees in 53% of the case reviews of femoral attachments and 36% of reviews of midportions of normal ACLs. Compared with knee extensions, the MR images for knee flexion provided better clarity in 48% of reviews of disrupted sites and 52% of residual bundles of torn ACLs. Normal ACL appeared taut in the knee extension and lax in semiflexion. Compared with MR images of knees in extension, MR images of knees in flexion more clearly delineate the femoral side of the ligament with wider space under the intercondylar roof and with decreased volume-averaging artifacts, providing superior visualization of normal and torn ACLs. 13 refs., 7 figs., 1 tab.

Maximum acceptable weight of lift reflects peak lumbosacral extension moments in a functional capacity evaluation test using free style, stoop and squat lifting.

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Kuijer, P P F M; van Oostrom, S H; Duijzer, K; van Dieën, J H

2012-01-01

It is unclear whether the maximum acceptable weight of lift (MAWL), a common psychophysical method, reflects joint kinetics when different lifting techniques are employed. In a within-participants study (n = 12), participants performed three lifting techniques--free style, stoop and squat lifting from knee to waist level--using the same dynamic functional capacity evaluation lifting test to assess MAWL and to calculate low back and knee kinetics. We assessed which knee and back kinetic parameters increased with the load mass lifted, and whether the magnitudes of the kinetic parameters were consistent across techniques when lifting MAWL. MAWL was significantly different between techniques (p = 0.03). The peak lumbosacral extension moment met both criteria: it had the highest association with the load masses lifted (r > 0.9) and was most consistent between the three techniques when lifting MAWL (ICC = 0.87). In conclusion, MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. Tests of maximum acceptable weight of lift (MAWL) from knee to waist height are used to assess work capacity of individuals with low-back disorders. This article shows that the MAWL reflects the lumbosacral extension moment across free style, stoop and squat lifting in healthy young males, but the relation between the load mass lifted and lumbosacral extension moment is different between techniques. This suggests that standardisation of lifting technique used in tests of the MAWL would be indicated if the aim is to assess the capacity of the low back.

Comparison of different passive knee extension torque-angle assessments

International Nuclear Information System (INIS)

Freitas, Sandro R; Vaz, João R; Bruno, Paula M; Valamatos, Maria J; Mil-Homens, Pedro

2013-01-01

Previous studies have used isokinetic dynamometry to assess joint torques and angles during passive extension of the knee, often without reporting upon methodological errors and reliability outcomes. In addition, the reliability of the techniques used to measure passive knee extension torque-angle and the extent to which reliability may be affected by the position of the subjects is also unclear. Therefore, we conducted an analysis of the intra- and inter-session reliability of two methods of assessing passive knee extension: (A) a 2D kinematic analysis coupled to a custom-made device that enabled the direct measurement of resistance to stretch and (B) an isokinetic dynamometer used in two testing positions (with the non-tested thigh either flexed at 45° or in the neutral position). The intra-class correlation coefficients (ICCs) of torque, the slope of the torque-angle curve, and the parameters of the mathematical model that were fit to the torque-angle data for the above conditions were measured in sixteen healthy male subjects (age: 21.4 ± 2.1 yr; BMI: 22.6 ± 3.3 kg m −2 ; tibial length: 37.4 ± 3.4 cm). The results found were: (1) methods A and B led to distinctly different torque-angle responses; (2) passive torque-angle relationship and stretch tolerance were influenced by the position of the non-tested thigh; and (3) ICCs obtained for torque were higher than for the slope and for the mathematical parameters that were fit to the torque-angle curve. In conclusion, the measurement method that is used and the positioning of subjects can influence the passive knee extension torque-angle outcome. (paper)

MR imaging of the knee extension and flexion. Diagnostic value for reconstructed anterior cruciate ligament

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Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine] [and others

1995-09-01

The purpose of this study is to determine the value of extended and flexed knee positions in MR imaging of the surgically reconstructed anterior cruciate ligament (ACL). With a mobile knee brace and a flexible surface coil, knee joint was enabled to extend to a full-extension and bend vertically to a semi-flexion (average 45deg of flexion) within the confines of the magnet bore. Sets of 3-mm-thick oblique sagittal proton-weighted turbo spin echo MR images were obtained at both extended and flexed positions. Twenty-five knees with intact ACL grafts and three knees with arthroscopically proved graft tears were evaluated. Compared to the extended position, MR images of flexed knee provided better delineation of the intact and complicated ACL grafts with statistical significance. The intact graft appeared relaxed at the semi-flexion and taut at the extension. Overall lengths of the intact grafts were readily identified at the flexion. Stretched along the intercondylar roof, the grafts were poorly outlined at the extension. MR images with knee flexion delineated the disrupted site from the impingement more clearly than that with knee extension. (author).

Secondary nerve lengthening to obtain full knee extension in popliteal pterygium syndrome.

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Boeckx, Willy; Misani, Marta; Vandermeeren, Liesbeth; Franck, Diane; Zirak, Christophe; Demey, Albert

2014-05-01

Microsurgical nerve lengthening was performed in two siblings presenting a popliteal pterigium syndrome with a knee flexion contracture of 80 degrees. After the first attempt for nerve lengthening and knee extension elsewhere, a repeated lengthening was required due to continuing tip-toe walking and recurrent knee contracture at the age of 3 years. An extensive external and internal interfascicular microsurgical neurolysis resulted in a lengthening of the nerves. A full length of leg procedure had to be performed, inclusive of Achilles tendon lengthening to obtain a complete extension of the knee and a 90-degree ankle flexion. Maintaining the leg in a fully extended position was obtained with a dynamic splinting in the first month after the operation. When timing the operation we have to consider the importance of adequate precision of the microsurgical neurolysis, down to the identification of the Fontana bands, and the adequate postoperative splinting. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

[Research progress of larger flexion gap than extension gap in total knee arthroplasty].

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Zhang, Weisong; Hao, Dingjun

2017-05-01

To summarize the progress of larger flexion gap than extension gap in total knee arthro-plasty (TKA). The domestic and foreign related literature about larger flexion gap than extension gap in TKA, and its impact factors, biomechanical and kinematic features, and clinical results were summarized. During TKA, to adjust the relations of flexion gap and extension gap is one of the key factors of successful operation. The biomechanical, kinematic, and clinical researches show that properly larger flexion gap than extension gap can improve both the postoperative knee range of motion and the satisfaction of patients, but does not affect the stability of the knee joint. However, there are also contrary findings. So adjustment of flexion gap and extension gap during TKA is still in dispute. Larger flexion gap than extension gap in TKA is a new joint space theory, and long-term clinical efficacy, operation skills, and related complications still need further study.

Dynamic knee stability and ballistic knee movement after ACL reconstruction: an application on instep soccer kick.

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Cordeiro, Nuno; Cortes, Nelson; Fernandes, Orlando; Diniz, Ana; Pezarat-Correia, Pedro

2015-04-01

The instep soccer kick is a pre-programmed ballistic movement with a typical agonist-antagonist coordination pattern. The coordination pattern of the kick can provide insight into deficient neuromuscular control. The purpose of this study was to investigate knee kinematics and hamstrings/quadriceps coordination pattern during the knee ballistic extension phase of the instep kick in soccer players after anterior cruciate ligament reconstruction (ACL reconstruction). Seventeen players from the Portuguese Soccer League participated in this study. Eight ACL-reconstructed athletes (experimental group) and 9 healthy individuals (control group) performed three instep kicks. Knee kinematics (flexion and extension angles at football contact and maximum velocity instants) were calculated during the kicks. Rectus femoris (RF), vastus lateralis, vastus medialis, biceps femoralis, and semitendinosus muscle activations were quantified during the knee extension phase. The ACL-reconstructed group had significantly lower knee extension angle (-1.2 ± 1.6, p ballistic control movement pattern between normal and ACL-reconstructed subjects. Performing open kinetic chain exercises using ballistic movements can be beneficial when recovering from ACL reconstruction. The exercises should focus on achieving multi-joint coordination and full knee extension (range of motion). III.

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

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Wing-Kai Lam

Full Text Available Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge.Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS, Flattened Heel Shoe (FHS, and Standard Heel Shoes (SHS. Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group x 3 (Shoe ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables.Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P < 0.05. Group effect revealed that elite players exhibited larger footstrike angle, faster approaching speed, lower peak horizontal force and horizontal loading rates but higher vertical loading rates and larger peak knee flexion and extension moments (P < 0.05. Analysis of Interactions of Group x Shoe for maximum and mean vertical loading rates (P < 0.05 indicated that elite players exhibited lower left maximum and mean vertical loading rates in RHS compared to FHS (P < 0.01, while the intermediate group did not show any Shoe effect on vertical loading rates.These findings indicate that shoe heel curvature would play some role in altering ground reaction force impact during badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

Voluntary movement frequencies in submaximal one- and two-legged knee extension exercise and pedaling

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Julie Sørbø Stang

2016-02-01

Full Text Available Understanding of behavior and control of human voluntary rhythmic stereotyped leg movements is useful in work to improve performance, function, and rehabilitation of exercising, healthy, and injured humans. The present study aimed at adding to the existing understanding within this field. To pursue the aim, correlations between freely chosen movement frequencies in relatively simple, single-joint, one- and two-legged knee extension exercise were investigated. The same was done for more complex, multiple-joint, one- and two-legged pedaling. These particular activities were chosen because they could be considered related to some extent, as they shared a key aspect of knee extension, and because they at the same time were different. The activities were performed at submaximal intensities, by healthy individuals (n=16, thereof 8 women; 23.4±2.7 years; 1.70±0.11 m; 68.6±11.2 kg.High and fair correlations (R-values of 0.99 and 0.75 occurred between frequencies generated with the dominant leg and the nondominant leg during knee extension exercise and pedaling, respectively. Fair to high correlations (R-values between 0.71 and 0.95 occurred between frequencies performed with each of the two legs in an activity, and the two-legged frequency performed in the same type of activity. In general, the correlations were higher for knee extension exercise than for pedaling. Correlations between knee extension and pedaling frequencies were of modest occurrence.The correlations between movement frequencies generated separately by each of the legs might be interpreted to support the following working hypothesis, which was based on existing literature. It is likely that involved central pattern generators (CPGs of the two legs share a common frequency generator or that separate frequency generators of each leg are attuned via interneuronal connections. Further, activity type appeared to be relevant. Thus, the apparent common rhythmogenesis for the two legs

Effects of trunk stability on isometric knee extension muscle strength measurement while sitting.

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Hirano, Masahiro; Gomi, Masahiro; Katoh, Munenori

2016-09-01

[Purpose] This study aimed to investigate the effect of trunk stability on isometric knee extension muscle strength measurement while sitting by performing simultaneous measurements with a handheld dynamometer (HHD) and an isokinetic dynamometer (IKD) in the same seated condition. [Subjects and Methods] The subjects were 30 healthy volunteers. Isometric knee extension muscle strength was simultaneously measured with a HHD and an IKD by using an IKD-specific chair. The measurement was performed twice. Measurement instrument variables and the number of measurements were examined by using the analysis of variance and correlation tests. [Results] The measurement instrument variables and the number of measurements were not significantly different. The correlation coefficients between the HHD and IKD measurements were ≥0.96. [Conclusion] Isometric knee extension muscle strength measurement using the HHD in the sitting position resulted in a lower value than that using the IKD, presumably because of the effect of trunk stability on the measurement. In the same seated posture with trunk stability, no significant difference in measurement values was observed between the HHD and IKD. The present findings suggest that trunk stability while seated during isometric knee extension muscle strength measurement influenced the HHD measurement.

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

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Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H; Bandholm, Thomas; Thorborg, Kristian; Zebis, Mette K; Andersen, Lars L

2012-12-01

While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric 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°). 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 (ptubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5). Knee extensions performed with 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 conditions displayed reciprocal EMG-angle patterns during the range of motion. 5.

Development of estimation system of knee extension strength using image features in ultrasound images of rectus femoris

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Murakami, Hiroki; Watanabe, Tsuneo; Fukuoka, Daisuke; Terabayashi, Nobuo; Hara, Takeshi; Muramatsu, Chisako; Fujita, Hiroshi

2016-04-01

The word "Locomotive syndrome" has been proposed to describe the state of requiring care by musculoskeletal disorders and its high-risk condition. Reduction of the knee extension strength is cited as one of the risk factors, and the accurate measurement of the strength is needed for the evaluation. The measurement of knee extension strength using a dynamometer is one of the most direct and quantitative methods. This study aims to develop a system for measuring the knee extension strength using the ultrasound images of the rectus femoris muscles obtained with non-invasive ultrasonic diagnostic equipment. First, we extract the muscle area from the ultrasound images and determine the image features, such as the thickness of the muscle. We combine these features and physical features, such as the patient's height, and build a regression model of the knee extension strength from training data. We have developed a system for estimating the knee extension strength by applying the regression model to the features obtained from test data. Using the test data of 168 cases, correlation coefficient value between the measured values and estimated values was 0.82. This result suggests that this system can estimate knee extension strength with high accuracy.

The influence of electromyographic biofeedback therapy on knee extension following anterior cruciate ligament reconstruction: a randomized controlled trial

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Christanell Franz

2012-11-01

Full Text Available Abstract Background Loss of knee extension and a deficit in quadriceps strength are frequently found following anterior cruciate ligament (ACL reconstruction. The aim of this study was to investigate whether the addition of Eletromyographic Biofeedback (EMG BFB therapy for the vastus medialis muscle to the in the early phase of the standard rehabilitation programme could improve the range of knee extension and strength after ACL reconstruction more than a standard rehabilitation programme. The correlation between EMG measurement and passive knee extension was also investigated. Method Sixteen patients, all of whom underwent endoscopic ACL reconstruction using patellar tendon autograft, were randomly assigned to two groups: • Control group (8 patients: standard rehabilitation protocol; with full weight-bearing postoperative, knee brace (0° extension, 90° flexion, electrical stimulation, aquatics and proprioceptive training. • The EMG BFB group (8 patients: EMG BFB was added to the standard rehabilitation protocol within the first postoperative week and during each session for the next 6 weeks. Each patent attended a total of 16 outpatient physiotherapy sessions following surgery. High-Heel-Distance (HHD Test, range of motion (ROM and integrated EMG (iEMG for vastus medialis were measured preoperatively, and at the 1, 2, 4 and 6-week follow ups. Additionally, knee function, swelling and pain were evaluated using standardized scoring scales. Results At 6 weeks, passive knee extension (p  0.01 differences were found between the two groups for the assessment of knee function, swelling and pain. Conclusion The results indicate that EMG BFB therapy, in the early phase of rehabilitation after ACL reconstruction, is useful in enhancing knee extension. Improved innervation of the vastus medialis can play a key role in the development of postoperative knee extension. EMG BFB therapy is a simple, inexpensive and valuable adjunct to conventional

Gear Shifting of Quadriceps during Isometric Knee Extension Disclosed Using Ultrasonography.

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Zhang, Shu; Huang, Weijian; Zeng, Yu; Shi, Wenxiu; Diao, Xianfen; Wei, Xiguang; Ling, Shan

2018-01-01

Ultrasonography has been widely employed to estimate the morphological changes of muscle during contraction. To further investigate the motion pattern of quadriceps during isometric knee extensions, we studied the relative motion pattern between femur and quadriceps under ultrasonography. An interesting observation is that although the force of isometric knee extension can be controlled to change almost linearly, femur in the simultaneously captured ultrasound video sequences has several different piecewise moving patterns. This phenomenon is like quadriceps having several forward gear ratios like a car starting from rest towards maximal voluntary contraction (MVC) and then returning to rest. Therefore, to verify this assumption, we captured several ultrasound video sequences of isometric knee extension and collected the torque/force signal simultaneously. Then we extract the shapes of femur from these ultrasound video sequences using video processing techniques and study the motion pattern both qualitatively and quantitatively. The phenomenon can be seen easier via a comparison between the torque signal and relative spatial distance between femur and quadriceps. Furthermore, we use cluster analysis techniques to study the process and the clustering results also provided preliminary support to the conclusion that, during both ramp increasing and decreasing phases, quadriceps contraction may have several forward gear ratios relative to femur.

The associations between quadriceps muscle strength, power, and knee joint mechanics in knee osteoarthritis: A cross-sectional study.

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Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A

2015-12-01

Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (Pknee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Progressive strength training (10 RM) commenced immediately after fast-track total knee arthroplasty: is it feasible?

DEFF Research Database (Denmark)

Jakobsen, Thomas Linding; Husted, Henrik; Kehlet, Henrik

2012-01-01

. They received rehabilitation including progressive strength training of the operated leg (leg press and knee-extension), using relative loads of 10 repetition maximum with three training sessions per week for 2 weeks. Rehabilitation was commenced 1 or 2 days after TKA. At each training session, knee pain, knee...... joint effusion and training load were recorded. Isometric knee-extension strength and maximal walking speed were measured before the first and last session. Results: The training load increased progressively (p training exercises......, but knee pain at rest and knee joint effusion (p training sessions. Isometric knee-extension strength and maximal walking speed increased by 147 and 112%, respectively. Conclusion: Progressive strength training initiated immediately after TKA seems feasible...

On the role of the patella, ACL and joint contact forces in the extension of the knee.

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Daniel J Cleather

Full Text Available Traditional descriptions of the knee suggest that the function of the patella is to facilitate knee extension by increasing the moment arm of the quadriceps muscles. Through modelling and evidence from the literature it is shown in this paper that the presence of the patella makes the ability of the quadriceps to rotate the thigh greater than their ability to rotate the tibia. Furthermore, this difference increases as the knee is flexed, thus demonstrating a pattern that is consistent with many human movements. This paper also shows that the anterior cruciate ligament plays a previously unheralded role in extending the shank and that translation at the tibiofemoral and patellofemoral joints is important in improving the capacity for thigh rotation when the knee is flexed. This study provides new insights as to how the structure of the knee is adapted to its purpose and illustrates how the functional anatomy of the knee contributes to its extension function.

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

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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.

Pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis

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Kierkegaard, Signe; Jørgensen, Peter Bo; Dalgas, Ulrik

2015-01-01

advancing functional tasks, and how these strategies are associated with leg extension power. The aim of the study was to investigate pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis compared with controls. MATERIALS AND METHODS: 57...... patients (mean age 65.6 years) scheduled for medial uni-compartmental knee arthroplasty, and 29 age and gender matched controls were included in this cross-sectional study. Leg extension power was tested with the Nottingham Leg Extension Power-Rig. Pelvic range of motion was derived from an inertia......-based measurement unit placed over the sacrum bone during walking, stair climbing and stepping. RESULTS: Patients had lower leg extension power than controls (20-39 %, P

Fun During Knee Rehabilitation: Feasibility and Acceptability Testing of a New Android-Based Training Device.

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Weber-Spickschen, Thomas Sanjay; Colcuc, Christian; Hanke, Alexander; Clausen, Jan-Dierk; James, Paul Abraham; Horstmann, Hauke

2017-01-01

The initial goals of rehabilitation after knee injuries and operations are to achieve full knee extension and to activate quadriceps muscle. In addition to regular physiotherapy, an android-based knee training device is designed to help patients achieve these goals and improve compliance in the early rehabilitation period. This knee training device combines fun in a computer game with muscular training or rehabilitation. Our aim was to test the feasibility and acceptability of this new device. 50 volunteered subjects enrolled to test out the computer game aided device. The first game was the high-striker game, which recorded maximum knee extension power. The second game involved controlling quadriceps muscular power to simulate flying an aeroplane in order to record accuracy of muscle activation. The subjects evaluated this game by completing a simple questionnaire. No technical problem was encountered during the usage of this device. No subjects complained of any discomfort after using this device. Measurements including maximum knee extension power, knee muscle activation and control were recorded successfully. Subjects rated their experience with the device as either excellent or very good and agreed that the device can motivate and monitor the progress of knee rehabilitation training. To the best of our knowledge, this is the first android-based tool available to fast track knee rehabilitation training. All subjects gave very positive feedback to this computer game aided knee device.

Pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis: a cross-sectional study.

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Kierkegaard, Signe; Jørgensen, Peter Bo; Dalgas, Ulrik; Søballe, Kjeld; Mechlenburg, Inger

2015-09-01

During movement tasks, patients with medial compartment knee osteoarthritis use compensatory strategies to minimise the joint load of the affected leg. Movement strategies of the knees and trunk have been investigated, but less is known about movement strategies of the pelvis during advancing functional tasks, and how these strategies are associated with leg extension power. The aim of the study was to investigate pelvic movement strategies and leg extension power in patients with end-stage medial compartment knee osteoarthritis compared with controls. 57 patients (mean age 65.6 years) scheduled for medial uni-compartmental knee arthroplasty, and 29 age and gender matched controls were included in this cross-sectional study. Leg extension power was tested with the Nottingham Leg Extension Power-Rig. Pelvic range of motion was derived from an inertia-based measurement unit placed over the sacrum bone during walking, stair climbing and stepping. Patients had lower leg extension power than controls (20-39 %, P 0.06). Furthermore, an inverse association (coefficient: -0.03 to -0.04; R (2) = 13-22 %) between leg extension power and pelvic range of motion during stair and step descending was found in the patients. Compared to controls, patients with medial compartment knee osteoarthritis use greater pelvic movements during advanced functional performance tests, particularly when these involve descending tasks. Further studies should investigate if it is possible to alter these movement strategies by an intervention aimed at increasing strength and power for the patients.

Vastus medialis motor unit properties in knee osteoarthritis

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Chess David G

2011-09-01

Full Text Available Abstract Background Maximal isometric quadriceps strength deficits have been widely reported in studies of knee osteoarthritis (OA, however little is known about the effect of osteoarthritis knee pain on submaximal quadriceps neuromuscular function. The purpose of this study was to measure vastus medialis motor unit (MU properties in participants with knee OA, during submaximal isometric contractions. Methods Vastus medialis motor unit potential (MUP parameters were assessed in 8 patients with knee OA and 8 healthy, sex and age-matched controls during submaximal isometric contractions (20% of maximum isometric torque. Unpaired t-tests were used to compare groups for demographic and muscle parameters. Results Maximum knee extension torque was ~22% lower in the OA group, a difference that was not statistically significantly (p = 0.11. During submaximal contractions, size related parameters of the needle MUPs (e.g. negative peak duration and amplitude-to-area ratio were greater in the OA group (p Conclusions Changes in MU recruitment and rate coding strategies in OA may reflect a chronic reinnervation process or a compensatory strategy in the presence of chronic knee pain associated with OA.

Tourniquet versus no tourniquet on knee-extension strength early after fast-track total knee arthroplasty; a randomized controlled trial

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Harsten, Andreas; Bandholm, Thomas Quaade; Kehlet, Henrik

2015-01-01

pressure was based on the patient's systolic pressure and a margin of 100mmHg. It was inflated immediately before surgery and deflated as soon as surgery ended. The primary outcome was the change in knee-extension strength from pre-surgery to 48h after surgery (primary end point). Secondary outcomes were...

Strain measurements of the tibial insert of a knee prosthesis using a knee motion simulator.

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Sera, Toshihiro; Iwai, Yuya; Yamazaki, Takaharu; Tomita, Tetsuya; Yoshikawa, Hideki; Naito, Hisahi; Matsumoto, Takeshi; Tanaka, Masao

2017-12-01

The longevity of a knee prosthesis is influenced by the wear of the tibial insert due to its posture and movement. In this study, we assumed that the strain on the tibial insert is one of the main reasons for its wear and investigated the influence of the knee varus-valgus angles on the mechanical stress of the tibial insert. Knee prosthesis motion was simulated using a knee motion simulator based on a parallel-link six degrees-of-freedom actuator and the principal strain and pressure distribution of the tibial insert were measured. In particular, the early stance phase obtained from in vivo X-ray images was examined because the knee is applied to the largest load during extension/flexion movement. The knee varus-valgus angles were 0° (neutral alignment), 3°, and 5° malalignment. Under a neutral orientation, the pressure was higher at the middle and posterior condyles. The first and second principal strains were larger at the high and low pressure areas, respectively. Even for a 3° malalignment, the load was concentrated at one condyle and the positive first principal strain increased dramatically at the high pressure area. The negative second principal strain was large at the low pressure area on the other condyle. The maximum equivalent strain was 1.3-2.1 times larger at the high pressure area. For a 5° malalignment, the maximum equivalent strain increased slightly. These strain and pressure measurements can provide the mechanical stress of the tibial insert in detail for determining the longevity of an artificial knee joint.

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

DEFF Research Database (Denmark)

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

2012-01-01

muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric......BACKGROUND/PURPOSE: 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...... 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 conditions...

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

DEFF Research Database (Denmark)

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

2012-01-01

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 conditions......BACKGROUND/PURPOSE: While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps...... muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. METHODS: 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric...

Validity and reliability of an instrumented leg-extension machine for measuring isometric muscle strength of the knee extensors.

Science.gov (United States)

Ruschel, Caroline; Haupenthal, Alessandro; Jacomel, Gabriel Fernandes; Fontana, Heiliane de Brito; Santos, Daniela Pacheco dos; Scoz, Robson Dias; Roesler, Helio

2015-05-20

Isometric muscle strength of knee extensors has been assessed for estimating performance, evaluating progress during physical training, and investigating the relationship between isometric and dynamic/functional performance. To assess the validity and reliability of an adapted leg-extension machine for measuring isometric knee extensor force. Validity (concurrent approach) and reliability (test and test-retest approach) study. University laboratory. 70 healthy men and women aged between 20 and 30 y (39 in the validity study and 31 in the reliability study). Intraclass correlation coefficient (ICC) values calculated for the maximum voluntary isometric torque of knee extensors at 30°, 60°, and 90°, measured with the prototype and with an isokinetic dynamometer (ICC2,1, validity study) and measured with the prototype in test and retest sessions, scheduled from 48 h to 72 h apart (ICC1,1, reliability study). In the validity analysis, the prototype showed good agreement for measurements at 30° (ICC2,1 = .75, SEM = 18.2 Nm) and excellent agreement for measurements at 60° (ICC2,1 = .93, SEM = 9.6 Nm) and at 90° (ICC2,1 = .94, SEM = 8.9 Nm). Regarding the reliability analysis, between-days' ICC1,1 were good to excellent, ranging from .88 to .93. Standard error of measurement and minimal detectable difference based on test-retest ranged from 11.7 Nm to 18.1 Nm and 32.5 Nm to 50.1 Nm, respectively, for the 3 analyzed knee angles. The analysis of validity and repeatability of the prototype for measuring isometric muscle strength has shown to be good or excellent, depending on the knee joint angle analyzed. The new instrument, which presents a relative low cost and easiness of transportation when compared with an isokinetic dynamometer, is valid and provides consistent data concerning isometric strength of knee extensors and, for this reason, can be used for practical, clinical, and research purposes.

Immediate effects of whole body vibration on patellar tendon properties and knee extension torque.

Science.gov (United States)

Rieder, F; Wiesinger, H-P; Kösters, A; Müller, E; Seynnes, O R

2016-03-01

Reports about the immediate effects of whole body vibration (WBV) exposure upon torque production capacity are inconsistent. However, the changes in the torque-angle relationship observed by some authors after WBV may hinder the measurement of torque changes at a given angle. Acute changes in tendon mechanical properties do occur after certain types of exercise but this hypothesis has never been tested after a bout of WBV. The purpose of the present study was to investigate whether tendon compliance is altered immediately after WBV, effectively shifting the optimal angle of peak torque towards longer muscle length. Twenty-eight subjects were randomly assigned to either a WBV (n = 14) or a squatting control group (n = 14). Patellar tendon CSA, stiffness and Young's modulus and knee extension torque-angle relationship were measured using ultrasonography and dynamometry 1 day before and directly after the intervention. Tendon CSA was additionally measured 24 h after the intervention to check for possible delayed onset of swelling. The vibration intervention had no effects on patellar tendon CSA, stiffness and Young's modulus or the torque-angle relationship. Peak torque was produced at ~70° knee angle in both groups at pre- and post-test. Additionally, the knee extension torque globally remained unaffected with the exception of a small (-6%) reduction in isometric torque at a joint angle of 60°. The present results indicate that a single bout of vibration exposure does not substantially alter patellar tendon properties or the torque-angle relationship of knee extensors.

Knee-extension strength, postural control and function are related to fracture type and thigh edema in patients with hip fracture

DEFF Research Database (Denmark)

Kristensen, Morten T; Bandholm, Thomas; Bencke, Jesper

2008-01-01

BACKGROUND: Post-surgery thigh edema, loss of knee-extension strength, and reduced physical performance are common following a hip fracture. It is not known if knee-extension strength and physical performance are related to the edema and fracture type. The aim of this study was to examine...... the influence of fracture type and post-surgery edema on physical performances in patients with hip fracture. METHODS: Fifteen women and five men admitted from their own home to an acute orthopedic hip fracture unit were examined. Ten had cervical and ten had intertrochanteric fractures. Correlations between...... fracture type and thigh edema in the fractured limb (% non-fractured) to physical performances of basic mobility, postural control (sway), and isometric knee-extension strength were examined. All measures, except those of basic mobility, were conducted at the time of discharge, 8.5 days post...

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Designs and performance of three new microprocessor-controlled knee joints.

Science.gov (United States)

Thiele, Julius; Schöllig, Christina; Bellmann, Malte; Kraft, Marc

2018-02-09

A crossover design study with a small group of subjects was used to evaluate the performance of three microprocessor-controlled exoprosthetic knee joints (MPKs): C-Leg 4, Plié 3 and Rheo Knee 3. Given that the mechanical designs and control algorithms of the joints determine the user outcome, the influence of these inherent differences on the functional characteristics was investigated in this study. The knee joints were evaluated during level-ground walking at different velocities in a motion analysis laboratory. Additionally, technical analyses using patents, technical documentations and X-ray computed tomography (CT) for each knee joint were performed. The technical analyses showed that only C-Leg 4 and Rheo Knee 3 allow microprocessor-controlled adaptation of the joint resistances for different gait velocities. Furthermore, Plié 3 is not able to provide stance extension damping. The biomechanical results showed that only if a knee joint adapts flexion and extension resistances by the microprocessor all known advantages of MPKs can become apparent. But not all users may benefit from the examined functions: e.g. a good accommodation to fast walking speeds or comfortable stance phase flexion. Hence, a detailed comparison of user demands and performance of the designated knee joint is mandatory to ensure a maximum in user outcome.

Motor units in vastus lateralis and in different vastus medialis regions show different firing properties during low-level, isometric knee extension contraction.

Science.gov (United States)

de Souza, Leonardo Mendes Leal; Cabral, Hélio Veiga; de Oliveira, Liliam Fernandes; Vieira, Taian Martins

2018-04-01

Architectural differences along vastus medialis (VM) and between VM and vastus lateralis (VL) are considered functionally important for the patellar tracking, knee joint stability and knee joint extension. Whether these functional differences are associated with a differential activity of motor units between VM and VL is however unknown. In the present study, we, therefore, investigate neuroanatomical differences in the activity of motor units detected proximo-distally from VM and from the VL muscle. Nine healthy volunteers performed low-level isometric knee extension contractions (20% of their maximum voluntary contraction) following a trapezoidal trajectory. Surface electromyograms (EMGs) were recorded from VM proximal and distal regions and from VL using three linear adhesive arrays of eight electrodes. The firing rate and recruitment threshold of motor units decomposed from EMGs were then compared among muscle regions. Results show that VL motor units reached lower mean firing rates in comparison with VM motor units, regardless of their position within VM (P motor units (P = .997). Furthermore, no significant differences in the recruitment threshold were observed for all motor units analysed (P = .108). Our findings possibly suggest the greater potential of VL to generate force, due to its fibres arrangement, may account for the lower discharge rate observed for VL then either proximally or distally detected motor units in VM. Additionally, the present study opens new perspectives on the importance of considering muscle architecture in investigations of the neural aspects of motor behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

Active knee joint flexibility and sports activity

DEFF Research Database (Denmark)

Hahn, Thomas; Foldspang, Anders; Vestergaard, E

1999-01-01

was significantly higher in women than in men and significantly positively associated with weekly hours of swimming and weekly hours of competitive gymnastics. Active knee flexion was significantly positively associated with participation in basketball, and significantly negatively associated with age and weekly......The aim of the study was to estimate active knee flexion and active knee extension in athletes and to investigate the potential association of each to different types of sports activity. Active knee extension and active knee flexion was measured in 339 athletes. Active knee extension...... hours of soccer, European team handball and swimming. The results point to sport-specific adaptation of active knee flexion and active knee extension. Udgivelsesdato: 1999-Apr...

Experimental knee pain reduces muscle strength

DEFF Research Database (Denmark)

Henriksen, Marius; Mortensen, Sara Rosager; Aaboe, Jens

2011-01-01

Pain is the principal symptom in knee pathologies and reduced muscle strength is a common observation among knee patients. However, the relationship between knee joint pain and muscle strength remains to be clarified. This study aimed at investigating the changes in knee muscle strength following...... experimental knee pain in healthy volunteers, and if these changes were associated with the pain intensities. In a crossover study, 18 healthy subjects were tested on 2 different days. Using an isokinetic dynamometer, maximal muscle strength in knee extension and flexion was measured at angular velocities 0....... Knee pain reduced the muscle strength by 5 to 15% compared to the control conditions (P knee extension and flexion at all angular velocities. The reduction in muscle strength was positively correlated to the pain intensity. Experimental knee pain significantly reduced knee extension...

Knee extension isometric torque production differences based on verbal motivation given to introverted and extroverted female children.

Science.gov (United States)

McWhorter, J Wesley; Landers, Merrill; Young, Daniel; Puentedura, E Louie; Hickman, Robbin A; Brooksby, Candi; Liveratti, Marc; Taylor, Lisa

2011-08-01

To date, little research has been conducted to test the efficacy of different forms of motivation based on a female child's personality type. The purpose of this study was to evaluate the ability of female children to perform a maximal knee extension isometric torque test with varying forms of motivation, based on the child's personality type (introvert vs. extrovert). The subjects were asked to perform a maximal isometric knee extension test under three different conditions: 1) with no verbal motivation, 2) with verbal motivation from the evaluator only, and 3) with verbal motivation from a group of their peers and the evaluator combined. A 2×3 mixed ANOVA was significant for an interaction (F 2,62=17.530; pintroverted group showed that scores without verbal motivation were significantly higher than with verbal motivation from the evaluator or the evaluator plus the peers. The extroverted group revealed that scores with verbal motivation from the evaluator or the evaluator plus the peers were significantly higher than without verbal motivation. Results suggest that verbal motivation has a varying effect on isometric knee extension torque production in female children with different personality types. Extroverted girls perform better with motivation, whereas introverted girls perform better without motivation from others.

The effects of knee direction, physical activity and age on knee joint position sense.

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Relph, Nicola; Herrington, Lee

2016-06-01

Previous research has suggested a decline in knee proprioception with age. Furthermore, regular participation in physical activity may improve proprioceptive ability. However, there is no large scale data on uninjured populations to confirm these theories. The aim of this study was to provide normative knee joint position data (JPS) from healthy participants aged 18-82years to evaluate the effects of age, physical activity and knee direction. A sample of 116 participants across five age groups was used. The main outcome measures were knee JPS absolute error scores into flexion and extension, Tegner activity levels and General Practitioner Physical Activity Questionnaire results. Absolute error scores in to knee flexion were 3.6°, 3.9°, 3.5°, 3.7° and 3.1° and knee extension were 2.7°, 2.5°, 2.9°, 3.4° and 3.9° for ages 15-29, 30-44, 45-59, 60-74 and 75 years old respectively. Knee extension and flexion absolute error scores were significantly different when age group data were pooled. There was a significant effect of age and activity level on joint position sense into knee extension. Age and lower Tegner scores were also negatively correlated to joint position sense into knee extension. The results provide some evidence for a decline in knee joint position sense with age. Further, active populations may have heightened static proprioception compared to inactive groups. Normative knee joint position sense data is provided and may be used by practitioners to identify patients with reduced proprioceptive ability. Copyright © 2016 Elsevier B.V. All rights reserved.

The role of knee joint moments and knee impairments on self-reported knee pain during gait in patients with knee osteoarthritis.

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O'Connell, Megan; Farrokhi, Shawn; Fitzgerald, G Kelley

2016-01-01

The association between high mechanical knee joint loading during gait with onset and progression of knee osteoarthritis has been extensively studied. However, less attention has been given to risk factors related to increased pain during gait. The purpose of this study was to evaluate knee joint moments and clinical characteristics that may be associated with gait-related knee pain in patients with knee osteoarthritis. Sixty-seven participants with knee osteoarthritis were stratified into three groups of no pain (n=18), mild pain (n=27), or moderate/severe pain (n=22) based on their self-reported symptoms during gait. All participants underwent three-dimensional gait analysis. Quadriceps strength, knee extension range of motion, radiographic knee alignment and self-reported measures of global pain and function were also quantified. The moderate/severe pain group demonstrated worse global pain (Pknee flexion moments during the midstance phase of gait compared to the no pain group (P=0.02). Additionally, the moderate/severe pain group demonstrated greater varus knee malalignment (P=0.009), which was associated with higher weight acceptance peak knee adduction moments (P=0.003) and worse global pain (P=0.003) and physical function scores (P=0.006). Greater knee flexion moment is present during the midstance phase of gait in patients with knee osteoarthritis and moderate/severe pain during gait. Additionally, greater varus malalignment may be a sign of increased global knee joint dysfunction that can influence many activities of daily living beyond gait. Copyright © 2015 Elsevier Ltd. All rights reserved.

Knee Pain during Strength Training Shortly following Fast-Track Total Knee Arthroplasty: A Cross-Sectional Study

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Bandholm, Thomas; Thorborg, Kristian; Lunn, Troels Haxholdt; Kehlet, Henrik; Jakobsen, Thomas Linding

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 ended with 1 single set to contraction failure (14 RM load). The individual loadings (kilograms) were determined during a familiarization session >72 hours prior. The patients rated their knee pain during each repetition, using a numerical rating scale (0–10). Results Two patients were lost to follow up. Knee pain increased with increasing load (20 RM: 3.1±2.0 points, 14 RM: 3.5±1.8 points, 8 RM: 4.3±2.5 points, P = 0.006), and repetitions to contraction failure (10% failure: 3.2±1.9 points, 100% failure: 5.4±1.6 points, Pknee pain 60 seconds after the final repetition (2.7±2.4 points) was not different from that recorded before strength training (2.7±1.8 points, P = 0.88). Conclusion Both loading and repetitions performed to contraction failure during knee- extension strength-training, increased post-operative knee pain during strength training implemented shortly following TKA. However, only the increase in pain during repetitions to contraction failure exceeded that defined as clinically relevant, and was very short-lived. Trial Registration Clinical

Medium-term evaluation of total knee arthroplasty without patellar replacement

Directory of Open Access Journals (Sweden)

José Wanderley Vasconcelos

2013-06-01

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

Comparison of erector spinae and hamstring muscle activities and lumbar motion during standing knee flexion in subjects with and without lumbar extension rotation syndrome.

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Kim, Si-hyun; Kwon, Oh-yun; Park, Kyue-nam; Kim, Moon-Hwan

2013-12-01

The aim of this study was to compare the activity of the erector spinae (ES) and hamstring muscles and the amount and onset of lumbar motion during standing knee flexion between individuals with and without lumbar extension rotation syndrome. Sixteen subjects with lumbar extension rotation syndrome (10 males, 6 females) and 14 healthy subjects (8 males, 6 females) participated in this study. During the standing knee flexion, surface electromyography (EMG) was used to measure muscle activity, and surface EMG electrodes were attached to both the ES and hamstring (medial and lateral) muscles. A three-dimensional motion analysis system was used to measure kinematic data of the lumbar spine. An independent-t test was conducted for the statistical analysis. The group suffering from lumbar extension rotation syndrome exhibited asymmetric muscle activation of the ES and decreased hamstring activity. Additionally, the group with lumbar extension rotation syndrome showed greater and earlier lumbar extension and rotation during standing knee flexion compared to the control group. These data suggest that asymmetric ES muscle activation and a greater amount of and earlier lumbar motion in the sagittal and transverse plane during standing knee flexion may be an important factor contributing to low back pain. Copyright © 2013 Elsevier Ltd. All rights reserved.

Estimation of the forces acting on the tibiofemoral joint during knee extension exercises

Directory of Open Access Journals (Sweden)

Rodrigo Rico Bini

2008-02-01

Full Text Available http://dx.doi.org/10.5007/1980-0037.2008v10n1p35 The objectives of this study were to: (1 evaluate the resistive torque of an open kinetic chain strength-training machine for performing knee extensions, and (2 perform an analysis estimating internal forces in the tibiofemoral joint. During a fi rst phase of the study, measurements were taken of the machine under analysis (external forces, and then calculations were performed to estimate forces on the lower limb (internal forces. Equations were defi ned to calculate human force (HF, and the moment of muscular force (MMF. Perpendicular muscular force (MFp and joint force (JFp, axial muscular force (MF” and joint force (JF”, and total muscular force (MF and joint force (JF were all calculated. Five knee angles were analyzed (zero, 30, 45, 60, and 90 degrees. A reduction was observed in HF at higher knee angles, while MF and JF also increased at the same time. HF was always lower than the load selected on the machine, which indicates a reduced overload imposed by the machine. The reduction observed in MFp and JFp at higher knee angles indicates a lower tendency to shear the tibia in relation to the femur. At the same time, there was an increase in JF” due to higher MF”. The biomechanical model proposed in this study has shown itself adequate for the day-to-day needs of professionals who supervise orient strength training.

Maximum Acceptable Weight of Lift reflects peak lumbosacral extension moments in a Functional Capacity Evaluation test using free style, stoop, and squat lifting

OpenAIRE

Kuijer, P.P.F.M.; van Oostrom, S.H.; Duijzer, K.; van Dieen, J.H.

2012-01-01

It is unclear whether the maximum acceptable weight of lift (MAWL), a common psychophysical method, reflects joint kinetics when different lifting techniques are employed. In a within-participants study (n = 12), participants performed three lifting techniques - free style, stoop and squat lifting from knee to waist level - using the same dynamic functional capacity evaluation lifting test to assess MAWL and to calculate low back and knee kinetics. We assessed which knee and back kinetic para...

Effectiveness of acute in-hospital physiotherapy with knee-extension strength training in reducing strength deficits in patients with a hip fracture

DEFF Research Database (Denmark)

Kronborg, Lise; Bandholm, Thomas; Palm, Henrik

2017-01-01

QUESTION: Is acute in-hospital physiotherapy with additional progressive knee-extension strength training (ST) of the fractured limb more effective in reducing knee-extension strength deficit at follow-up compared to physiotherapy without strength training in patients with a hip fracture? DESIGN......: Assessor blinded, randomised controlled trial with intention-to-treat analysis. PARTICIPANTS: 90 patients with a hip fracture admitted to an acute orthopaedic Hip Fracture Unit at a university hospital between October 2013 and May 2015. INTERVENTION: Daily physiotherapy with or without progressive knee...... strength training from baseline to follow-up. In the per-protocol analysis of non-missing data, significant between-group improvements by 10.5% (95% CI 0.3; 20.7) were found in favour of additional ST. No significant between-group differences were found in any secondary outcome. CONCLUSION: Physiotherapy...

Differences in hamstring activation characteristics between the acceleration and maximum-speed phases of sprinting.

Science.gov (United States)

Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

2018-06-01

This study aimed to investigate activation characteristics of the biceps femoris long head (BFlh) and semitendinosus (ST) muscles during the acceleration and maximum-speed phases of sprinting. Lower-extremity kinematics and electromyographic (EMG) activities of the BFlh and ST muscles were examined during the acceleration sprint and maximum-speed sprint in 13 male sprinters during an overground sprinting. Differences in hamstring activation during each divided phases and in the hip and knee joint angles and torques at each time point of the sprinting gait cycle were determined between two sprints. During the early stance of the acceleration sprint, the hip extension torque was significantly greater than during the maximum-speed sprint, and the relative EMG activation of the BFlh muscle was significantly higher than that of the ST muscle. During the late stance and terminal mid-swing of maximum-speed sprint, the knee was more extended and a higher knee flexion moment was observed compared to the acceleration sprint, and the ST muscle showed higher activation than that of the BFlh. These results indicate that the functional demands of the medial and lateral hamstring muscles differ between two different sprint performances.

Does shoe heel design influence ground reaction forces and knee moments during maximum lunges in elite and intermediate badminton players?

Science.gov (United States)

Lam, Wing-Kai; Ryue, Jaejin; Lee, Ki-Kwang; Park, Sang-Kyoon; Cheung, Jason Tak-Man; Ryu, Jiseon

2017-01-01

Lunge is one frequently executed movement in badminton and involves a unique sagittal footstrike angle of more than 40 degrees at initial ground contact compared with other manoeuvres. This study examined if the shoe heel curvature design of a badminton shoe would influence shoe-ground kinematics, ground reaction forces, and knee moments during lunge. Eleven elite and fifteen intermediate players performed five left-forward maximum lunge trials with Rounded Heel Shoe (RHS), Flattened Heel Shoe (FHS), and Standard Heel Shoes (SHS). Shoe-ground kinematics, ground reaction forces, and knee moments were measured by using synchronized force platform and motion analysis system. A 2 (Group) x 3 (Shoe) ANOVA with repeated measures was performed to determine the effects of different shoes and different playing levels, as well as the interaction of two factors on all variables. Shoe effect indicated that players demonstrated lower maximum vertical loading rate in RHS than the other two shoes (P badminton lunge. The differences in impact loads and knee moments between elite and intermediate players may be useful in optimizing footwear design and training strategy to minimize the potential risks for impact related injuries in badminton.

Strength and Functional Improvement Using Pneumatic Brace with Extension Assist for End-Stage Knee Osteoarthritis: A Prospective, Randomized trial.

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Cherian, Jeffrey J; Bhave, Anil; Kapadia, Bhaveen H; Starr, Roland; McElroy, Mark J; Mont, Michael A

2015-05-01

Pneumatic unloader bracing with extension assists have been proposed as a non-operative modality that may delay the need for knee surgery by reducing pain and improving function. This prospective, randomized trial evaluated 52 patients who had knee osteoarthritis for changes in: (1) muscle strength; (2) objective functional improvements; (3); subjective functional improvements; (4) pain; (5) quality of life; and (6) conversion to total knee arthroplasty (TKA) compared to standard of care. Patient outcomes were evaluated at a minimum 3 months. Braced patient's demonstrated significant improvements in muscle strength, several functional tests, and patient reported outcomes when compared to the matched cohort. These results are encouraging and suggest that this device may represent a promising alternative to standard treatment methods for knee osteoarthritis. Copyright © 2014 Elsevier Inc. All rights reserved.

Knee flexion with quadriceps cocontraction: A new therapeutic exercise for the early stage of ACL rehabilitation.

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Biscarini, Andrea; Contemori, Samuele; Busti, Daniele; Botti, Fabio M; Pettorossi, Vito E

2016-12-08

Quadriceps strengthening exercises designed for the early phase of anterior cruciate ligament (ACL) rehabilitation should limit the anterior tibial translation developed by quadriceps contraction near full knee extension, in order to avoid excessive strain on the healing tissue. We hypothesize that knee-flexion exercises with simultaneous voluntary contraction of quadriceps (voluntary quadriceps cocontraction) can yield considerable levels of quadriceps activation while preventing the tibia from translating forward relative to the femur. Electromyographic activity in quadriceps and hamstring muscles was measured in 20 healthy males during isometric knee-flexion exercises executed near full knee extension with maximal voluntary effort of quadriceps cocontraction and external resistance (R) ranging from 0% to 60% of the 1-repetition maximum (1RM). Biomechanical modeling was applied to derive the shear (anterior/posterior) tibiofemoral force developed in each exercise condition. Isometric knee-flexion exercises with small external resistance (R=10% 1RM) and maximal voluntary effort of quadriceps cocontraction yielded a net posterior (ACL-unloading) tibial pull (P=0.005) and levels of activation of 32%, 50%, and 45% of maximum voluntary isometric contraction, for the rectus femoris, vastus medialis, and vastus lateralis, respectively. This exercise might potentially rank as one of the most appropriate quadriceps strengthening interventions in the early phase of ACL rehabilitation. Copyright © 2016 Elsevier Ltd. All rights reserved.

No Exacerbation of Knee Joint Pain and Effusion Following Preoperative Progressive Resistance Training in Patients Scheduled for Total Knee Arthroplasty: Secondary Analyses From a Randomized Controlled Trial.

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Skoffer, Birgit; Dalgas, Ulrik; Maribo, Thomas; Søballe, Kjeld; Mechlenburg, Inger

2017-11-09

Preoperative progressive resistance training (PRT) is controversial in patients scheduled for total knee arthroplasty (TKA), because of the concern that it may exacerbate knee joint pain and effusion. To examine whether preoperative PRT initiated 5 weeks prior to TKA would exacerbate pain and knee effusion, and would allow a progressively increased training load throughout the training period that would subsequently increase muscle strength. Secondary analyses from a randomized controlled trial. University Hospital and a Regional Hospital. A total of 30 patients who were scheduled for TKA due to osteoarthritis and assigned as the intervention group. Patients underwent unilateral PRT (3 sessions per week). Exercise loading was 12 repetitions maximum (RM) with progression toward 8 RM. The training program consisted of 6 exercises performed unilaterally. Before and after each training session, knee joint pain was rated on an 11-point scale, effusion was assessed by measuring the knee joint circumference, and training load was recorded. The first and last training sessions were initiated by 1 RM testing of unilateral leg press, unilateral knee extension, and unilateral knee flexion. The median pain change score from before to after each training session was 0 at all training sessions. The average increase in knee joint effusion across the 12 training sessions was a mean 0.16 cm ± 0.23 cm. No consistent increase in knee joint effusion after training sessions during the training period was found (P = .21). Training load generally increased, and maximal muscle strength improved as follows: unilateral leg press: 18% ± 30% (P = .03); unilateral knee extension: 81% ± 156% (P knee flexion: 53% ± 57% (P knee joint pain and effusion, despite a substantial progression in loading and increased muscle strength. Concerns for side effects such as pain and effusion after PRT seem unfounded. To be determined. Copyright © 2017. Published by Elsevier Inc.

Kinematic analysis of anterior cruciate ligament reconstruction in total knee arthroplasty

Science.gov (United States)

Liu, Hua-Wei; Ni, Ming; Zhang, Guo-Qiang; Li, Xiang; Chen, Hui; Zhang, Qiang; Chai, Wei; Zhou, Yong-Gang; Chen, Ji-Ying; Liu, Yu-Liang; Cheng, Cheng-Kung; Wang, Yan

2016-01-01

Background: This study aims to retain normal knee kinematics after knee replacement surgeries by reconstructing anterior cruciate ligament during total knee arthroplasty. Method: We use computational simulation tools to establish four dynamic knee models, including normal knee model, posterior cruciate ligament retaining knee model, posterior cruciate ligament substituting knee model, and anterior cruciate ligament reconstructing knee model. Our proposed method utilizes magnetic resonance images to reconstruct solid bones and attachments of ligaments, and assemble femoral and tibial components according representative literatures and operational specifications. Dynamic data of axial tibial rotation and femoral translation from full-extension to 135 were measured for analyzing the motion of knee models. Findings: The computational simulation results show that comparing with the posterior cruciate ligament retained knee model and the posterior cruciate ligament substituted knee model, reconstructing anterior cruciate ligament improves the posterior movement of the lateral condyle, medial condyle and tibial internal rotation through a full range of flexion. The maximum posterior translations of the lateral condyle, medial condyle and tibial internal rotation of the anterior cruciate ligament reconstructed knee are 15.3 mm, 4.6 mm and 20.6 at 135 of flexion. Interpretation: Reconstructing anterior cruciate ligament in total knee arthroplasty has been approved to be an more efficient way of maintaining normal knee kinematics comparing to posterior cruciate ligament retained and posterior cruciate ligament substituted total knee arthroplasty. PMID:27347334

The effect of knee brace and knee sleeve on the proprioception of the knee in young non-professional healthy sportsmen.

Science.gov (United States)

Bottoni, G; Herten, A; Kofler, P; Hasler, M; Nachbauer, W

2013-12-01

Proprioception has been defined as the capacity to feel the position of a joint in space as sensed by the central nervous system. Prophylactic knee braces are supposed to help in knee injury prevention not just with a mechanical support of the joint but also improving proprioception. The main aim of this study was to determine the effects of a knee brace and a knee sleeve on knee proprioception. The secondary aim was to determine if different starting angles of the knee and different movement directions influence knee proprioception. We tested a group of twenty healthy male sport students without knee injuries. They were tested with the brace, with the sleeve and without support. The threshold of detection of passive knee movement with a starting knee angle of 30° and 60°, both in flexion and extension was determined. We did not find any statistically significant change in the threshold of detection of passive knee movement wearing the brace or the sleeve compared to the unsupported condition (p=0.462, α=0.05). We found a significantly lower proprioceptive sensitivity starting at the more flexed knee angle (p=0.005, α=0.05) and moving in extension than in the other test situations (p=0.001, α=0.05). Movement direction and starting position appear to influence the threshold of detection of passive knee movement. The results of this study also suggest that knee supports do not influence either positively or negatively knee proprioception of uninjured active subjects. Copyright © 2013 Elsevier B.V. All rights reserved.

Knee joint loading in knee osteoarthritis: influence of abdominal and thigh fat.

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Messier, Stephen P; Beavers, Daniel P; Loeser, Richard F; Carr, J Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J; Hunter, David J; Devita, Paul

2014-09-01

Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee joint loads in older overweight and obese adults with knee osteoarthritis (OA). Fat depots were quantified using computed tomography, and total lean and fat mass were determined with dual energy x-ray absorptiometry in 176 adults (age, 66.3 yr; body mass index, 33.5 kg·m) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Higher total body mass was significantly associated (P ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (P knee extensor moments (P = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (P = 0.0001), shear (P knee extension moment (P = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (P = 0.002). A regression model that included total thigh and total abdominal fat found that both were significantly associated with knee compressive and shear forces (P ≤ 0.04). Thigh fat was associated with knee abduction (P = 0.03) and knee extension moment (P = 0.02). Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA.

Preliminary analysis of knee stress in Full Extension Landing

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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.

Valgus-varus motion of the knee in normal level walking and stair climbing.

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Yu, B; Stuart, M J; Kienbacher, T; Growney, E S; An, K-N

1997-07-01

OBJECTIVE: The knee valgus-varus moment and the knee angles were compared between normal level walking and stair climbing. DESIGN: Ten healthy subjects were tested for ascent, descent, and level walking. BACKGROUND: An understanding of the normal valgus-varus motion of the knee during stair climbing is needed to apply biomechanical analysis of stair climbing as a evaluation tool for knee osteoarthritis patients. METHODS: A motion analysis system, three force plates, and a flight of stairs were used to collect kinematic and kinetic data. The knee angles and moments were calculated from the collected kinematic and kinetic data. RESULTS: The knee varus angle for the maximum knee valgus moments in stair climbing was significantly greater than that in level walking. The knee valgus moment was significantly correlated to ground reaction forces and knee valgus-varus angle during stair climbing and level walking. CONCLUSIONS: There is a coupling between the knee valgus-varus motion and flexion-extension motion. Ground reaction forces are the major contributors to the within-subject variation in the knee valgus-varus moment during stair climbing and level walking. The knee valgus-varus angle is a major contributor to the between-subject variation in the knee valgus moment during stair climbing and level walking.

KNEE-JOINT LOADING IN KNEE OSTEOARTHRITIS: INFLUENCE OF ABDOMINAL AND THIGH FAT

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Messier, Stephen P.; Beavers, Daniel P.; Loeser, Richard F.; Carr, J. Jeffery; Khajanchi, Shubham; Legault, Claudine; Nicklas, Barbara J.; Hunter, David J.; DeVita, Paul

2014-01-01

Purpose Using three separate models that included total body mass, total lean and total fat mass, and abdominal and thigh fat as independent measures, we determined their association with knee-joint loads in older overweight and obese adults with knee osteoarthritis (OA). Methods Fat depots were quantified using computed tomography and total lean and fat mass determined with dual energy x-ray absorptiometry in 176 adults (age = 66.3 yr., BMI = 33.5 kg·m−2) with radiographic knee OA. Knee moments and joint bone-on-bone forces were calculated using gait analysis and musculoskeletal modeling. Results Higher total body mass was significantly associated (p ≤ 0.0001) with greater knee compressive and shear forces, compressive and shear impulses (p knee extensor moments (p = 0.003). Regression analysis with total lean and total fat mass as independent variables revealed significant positive associations of total fat mass with knee compressive (p = 0.0001), shear (p knee extension moment (p = 0.008). Gastrocnemius and quadriceps forces were positively associated with total fat mass. Total lean mass was associated with knee compressive force (p = 0.002). A regression model that included total thigh and total abdominal fat found both were significantly associated with knee compressive and shear forces (p ≤ 0.04). Thigh fat was associated with the knee abduction (p = 0.03) and knee extension moment (p = 0.02). Conclusions Thigh fat, consisting predominately of subcutaneous fat, had similar significant associations with knee joint forces as abdominal fat despite its much smaller volume and could be an important therapeutic target for people with knee OA. PMID:25133996

Measurement of fatigue in knee flexor and extensor muscles.

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Kawabata, Y; Senda, M; Oka, T; Yagata, Y; Takahara, Y; Nagashima, H; Inoue, H

2000-04-01

In order to examine fatigue of the knee flexor and extensor muscles and to investigate the characteristics of muscular fatigue in different sports, a Cybex machine was used to measure muscle fatigue and recovery during isokinetic knee flexion and extension. Eighteen baseball players, 12 soccer players and 13 marathon runners were studied. Each subject was tested in the sitting position and made to perform 50 consecutive right knee bends and stretches at maximum strength. This was done 3 times with an interval of 10 min between each series. The peak torque to body weight ratio and the fatigue rate were determined in each case. In all subjects, the peak torque to body weight ratio was higher for extensors than flexors. Over the 3 trials, the fatigue rate of extensors showed little change, while that of flexors had a tendency to increase. In each subject, knee extensors showed a high fatigue rate but a quick recovery, while knee flexors showed a low fatigue rate but a slow recovery. As the marathon runners had the smallest fatigue rates for both flexors and extensors, we concluded that marathon runners had more stamina than baseball players and soccer players.

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

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

2015-06-01

This study aimed to determine the influence of the head, upper trunk, and foot position on the passive knee extension (PKE) torque-angle response. PKE tests were performed in 10 healthy subjects using an isokinetic dynamometer at 2°/s. Subjects lay in the supine position with their hips flexed to 90°. The knee angle, passive torque, surface electromyography (EMG) of the semitendinosus and quadriceps vastus medialis, and stretch discomfort were recorded in six body positions during PKE. The different maximal active positions of the cervical spine (neutral; flexion; extension), thoracic spine (neutral; flexion), and ankle (neutral; dorsiflexion) were passively combined for the tests. Visual analog scale scores and EMG were unaffected by body segment positioning. An effect of the ankle joint was verified on the peak torque and knee maximum angle when the ankle was in the dorsiflexion position (P torque (P torque when the cervical and thoracic spines were flexed (P torque-angle response since different positions of head, upper trunk, and foot induce dissimilar knee mechanical responses during passive extension. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Maximum Interconnectedness and Availability for Directional Airborne Range Extension Networks

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2016-08-29

IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS 1 Maximum Interconnectedness and Availability for Directional Airborne Range Extension Networks Thomas...2 IEEE TRANSACTIONS ON WIRELESS COMMUNICATIONS I. INTRODUCTION Tactical military networks both on land and at sea often have restricted transmission...a standard definition in graph theoretic and networking literature that is related to, but different from, the metric we consider. August 29, 2016

Improvements in force variability and structure from vision- to memory-guided submaximal isometric knee extension in subacute stroke.

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Chow, John W; Stokic, Dobrivoje S

2018-03-01

We examined changes in variability, accuracy, frequency composition, and temporal regularity of force signal from vision-guided to memory-guided force-matching tasks in 17 subacute stroke and 17 age-matched healthy subjects. Subjects performed a unilateral isometric knee extension at 10, 30, and 50% of peak torque [maximum voluntary contraction (MVC)] for 10 s (3 trials each). Visual feedback was removed at the 5-s mark in the first two trials (feedback withdrawal), and 30 s after the second trial the subjects were asked to produce the target force without visual feedback (force recall). The coefficient of variation and constant error were used to quantify force variability and accuracy. Force structure was assessed by the median frequency, relative spectral power in the 0-3-Hz band, and sample entropy of the force signal. At 10% MVC, the force signal in subacute stroke subjects became steadier, more broadband, and temporally more irregular after the withdrawal of visual feedback, with progressively larger error at higher contraction levels. Also, the lack of modulation in the spectral frequency at higher force levels with visual feedback persisted in both the withdrawal and recall conditions. In terms of changes from the visual feedback condition, the feedback withdrawal produced a greater difference between the paretic, nonparetic, and control legs than the force recall. The overall results suggest improvements in force variability and structure from vision- to memory-guided force control in subacute stroke despite decreased accuracy. Different sensory-motor memory retrieval mechanisms seem to be involved in the feedback withdrawal and force recall conditions, which deserves further study. NEW & NOTEWORTHY We demonstrate that in the subacute phase of stroke, force signals during a low-level isometric knee extension become steadier, more broadband in spectral power, and more complex after removal of visual feedback. Larger force errors are produced when recalling

Knee strength retention and analgesia with continuous perineural fentanyl infusion after total knee replacement: randomized controlled trial.

Science.gov (United States)

Mangar, Devanand; Karlnoski, Rachel A; Sprenker, Collin J; Downes, Katheryne L; Taffe, Narrene; Wainwright, Robert; Gustke, Kenneth; Bernasek, Thomas L; Camporesi, Enrico

2014-04-01

Despite providing adequate pain relief, a femoral nerve block can induce postoperative muscle weakness after total knee arthoplasty (TKA). Fentanyl has been shown to have peripheral effects but has not been used as a perineural infusate alone after TKA. Sixty patients scheduled for TKA were randomized to one of three blinded groups: a continuous 24 h infusion of either fentanyl 3 μg/ml, ropivacaine 0.1%, or 0.9% normal saline through a femoral nerve sheath catheter at 10 ml/h. The main outcome was maximum voluntary isometric contraction (MVIC) in the quadriceps femoris (knee extension), measured by a handheld dynamometer (Nm/kg). Other variables assessed were preoperative and postoperative visual analog scale (VAS) scores, hamstrings MVIC (knee flexion), active range of motion of the operative knee, distance ambulated, incidence of knee buckling, supplemental morphine usage, postoperative side effects, and serum fentanyl levels. Quadriceps MVIC values were significantly greater in the fentanyl group compared to the group that received ropivacaine (median values, 0.08 vs. 0.03 Nm/kg; p = 0.028). The incidence of postoperative knee buckling upon ambulation was higher in the ropivacaine group compared to the fentanyl group, although not statistically significant (40% vs. 15 %, respectively; p = 0.077). VAS scores while ambulating were not significantly different between the fentanyl group and the ropivacaine group (p = 0.270). Postoperative morphine consumption, nausea and vomiting, and resting VAS scores were similar among the three groups. A continuous perineural infusion of fentanyl produced greater strength retention than ropivacaine post-TKA.

MRI demonstrates the extension of juxta-articular venous malformation of the knee and correlates with joint changes

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Jans, L. [University of Melbourne, Royal Children' s Hospital, Department of Medical Imaging, Melbourne, Victoria (Australia); Ghent University Hospital, Department of Radiology and Medical Imaging, Gent (Belgium); Ditchfield, M.; Jaremko, J.L.; Stephens, N. [University of Melbourne, Royal Children' s Hospital, Department of Medical Imaging, Melbourne, Victoria (Australia); Verstraete, K. [Ghent University Hospital, Department of Radiology and Medical Imaging, Gent (Belgium)

2010-07-15

Juxta-articular venous malformations (VMs) are uncommon, but may cause early arthropathy of the knee in children and adolescents. We sought to describe the prevalence, extent and initial magnetic resonance imaging (MRI) features of knee arthropathy in children with VM adjacent to the knee joint. Thirty-five patients with VM adjacent to the knee who had MRI performed between 2000 and 2009 were identified through a keyword search of the radiology information system. VM extended to the joint in 17 of the 35 patients (5.4-21.5 years, mean 11.8 years). Most of these 17 patients had joint changes (15/17, 88%), most commonly haemosiderin deposition (14/17, 82%). Other findings included the presence of subchondral bone lesions (eight, 47%), cartilage loss (six, 35%), synovial thickening (six, 35%), marrow oedema (six, 35%), joint effusion (five, 29%), subchondral cysts (five, 29%) and one loose body (6%). VM location and size did not correlate with the degree of articular involvement. Joint changes were present in focal as well as non-discrete VM. We found that the frequency of arthropathy increased with extension of VM into the joint itself. This finding stresses the importance of early MRI evaluation of all juxta-articular VM. (orig.)

Effects of Proprioceptive Neuromuscular Facilitation Stretching and Kinesiology Taping on Pelvic Compensation During Double-Knee Extension

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Lee Seung-Woong

2015-12-01

Full Text Available Shortened hamstrings are likely to restrict the anterior pelvic tilt and induce a slumped posture due to the posterior pelvic tilt. This study was conducted to compare the effects of proprioceptive neuromuscular facilitation (PNF stretching and modified anterior pelvic tilt taping (APTT on hamstring shortness-associated pelvic compensation while executing seated double-knee extension. Male college students (28 healthy young adults; mean age: 21.4 ± 2.1 years with hamstring shortness were recruited as study subjects and randomly assigned to either the PNF stretching group (control group or the APTT group (experimental group. In all the subjects, changes in the movement distance of the centre of gluteal pressure (COGP as well as rectus abdominis (RA and semitendinosus (SEM muscle activities were measured during seated double-knee extension while the respective intervention method was applied. Both groups showed significant decreases in COGP distance and RA muscle activity compared with their respective baseline values (p < 0.05, however, no significant changes were observed in SEM muscle activity. We can infer that not only a direct intervention on the hamstring, such as PNF stretching, but also a modified APTT-mediated pelvic intervention may be used as a method for reducing pelvic compensation induced by hamstring shortness.

Position controlled Knee Rehabilitation Orthotic Device for Patients after Total Knee Replacement Arthroplasty

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Wannaphan, Patsiri; Chanthasopeephan, Teeranoot

2016-11-01

Knee rehabilitation after total knee replacement arthroplasty is essential for patients during their post-surgery recovery period. This study is about designing one degree of freedom knee rehabilitation equipment to assist patients for their post-surgery exercise. The equipment is designed to be used in sitting position with flexion/extension of knee in sagittal plane. The range of knee joint motion is starting from 0 to 90 degrees angle for knee rehabilitation motion. The feature includes adjustable link for different human proportions and the torque feedback control at knee joint during rehabilitation and the control of flexion/extension speed. The motion of the rehabilitation equipment was set to move at low speed (18 degrees/sec) for knee rehabilitation. The rehabilitation link without additional load took one second to move from vertical hanging up to 90° while the corresponding torque increased from 0 Nm to 2 Nm at 90°. When extra load is added, the link took 1.5 seconds to move to 90° The torque is then increased from 0 Nm to 4 Nm. After a period of time, the speed of the motion can be varied. User can adjust the motion to 40 degrees/sec during recovery activity of the knee and users can increase the level of exercise or motion up to 60 degrees/sec to strengthen the muscles during throughout their rehabilitation program depends on each patient. Torque control is included to prevent injury. Patients can use the equipment for home exercise to help reduce the number of hospital visit while the patients can receive an appropriate therapy for their knee recovery program.

Genome-wide linkage scan for maximum and length-dependent knee muscle strength in young men: significant evidence for linkage at chromosome 14q24.3.

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De Mars, G; Windelinckx, A; Huygens, W; Peeters, M W; Beunen, G P; Aerssens, J; Vlietinck, R; Thomis, M A I

2008-05-01

Maintenance of high muscular fitness is positively related to bone health, functionality in daily life and increasing insulin sensitivity, and negatively related to falls and fractures, morbidity and mortality. Heritability of muscle strength phenotypes ranges between 31% and 95%, but little is known about the identity of the genes underlying this complex trait. As a first attempt, this genome-wide linkage study aimed to identify chromosomal regions linked to muscle and bone cross-sectional area, isometric knee flexion and extension torque, and torque-length relationship for knee flexors and extensors. In total, 283 informative male siblings (17-36 years old), belonging to 105 families, were used to conduct a genome-wide SNP-based multipoint linkage analysis. The strongest evidence for linkage was found for the torque-length relationship of the knee flexors at 14q24.3 (LOD = 4.09; p<10(-5)). Suggestive evidence for linkage was found at 14q32.2 (LOD = 3.00; P = 0.005) for muscle and bone cross-sectional area, at 2p24.2 (LOD = 2.57; p = 0.01) for isometric knee torque at 30 degrees flexion, at 1q21.3, 2p23.3 and 18q11.2 (LOD = 2.33, 2.69 and 2.21; p<10(-4) for all) for the torque-length relationship of the knee extensors and at 18p11.31 (LOD = 2.39; p = 0.0004) for muscle-mass adjusted isometric knee extension torque. We conclude that many small contributing genes rather than a few important genes are involved in causing variation in different underlying phenotypes of muscle strength. Furthermore, some overlap in promising genomic regions were identified among different strength phenotypes.

Femoropatellar gliding movement during active stretching of the knee

International Nuclear Information System (INIS)

Brossmann, J.; Muhle, C.; Melchert, U.H.; Spielmann, R.P.; Schroeder, C.; Hassenpflug, J.

1992-01-01

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.) [de

Effectiveness of acute in-hospital physiotherapy with knee-extension strength training in reducing strength deficits in patients with a hip fracture: A randomised controlled trial.

Directory of Open Access Journals (Sweden)

Lise Kronborg

Full Text Available Is acute in-hospital physiotherapy with additional progressive knee-extension strength training (ST of the fractured limb more effective in reducing knee-extension strength deficit at follow-up compared to physiotherapy without strength training in patients with a hip fracture?Assessor blinded, randomised controlled trial with intention-to-treat analysis.90 patients with a hip fracture admitted to an acute orthopaedic Hip Fracture Unit at a university hospital between October 2013 and May 2015.Daily physiotherapy with or without progressive knee-extension strength training (10RM, 3 x 10 repetitions, of the fractured limb using ankle weight cuffs conducted by ward physical therapists during hospital stay.Primary outcome was the change in maximal isometric knee-extension strength in the fractured limb in percentage of the non-fractured limb from inclusion to postoperative day 10 or discharge (follow-up. Secondary outcome was Timed Up and Go test measured early after surgery and at follow-up.In the intention-to-treat analysis of between-group differences, the primary outcome improved 8.1% (95% CI -2.3; 18.4 by additional strength training from baseline to follow-up. In the per-protocol analysis of non-missing data, significant between-group improvements by 10.5% (95% CI 0.3; 20.7 were found in favour of additional ST. No significant between-group differences were found in any secondary outcome.Physiotherapy with addition of 5 sessions of ST yielded no additional improvements compared to physiotherapy without strength training in reducing the knee-extension strength deficit at follow-up in patients with a hip fracture. It is debatable whether larger improvements than the observed 8-10% can be expected given that only five exercise sessions, on average, were completed. In fragile patients with a hip fracture in the acute phase, where the ability to participate in functional exercise is compromised, we still consider early strength training a

KNEE ISOKINETIC TORQUE IMBALANCE IN FEMALE FUTSAL PLAYERS

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Ana Carolina de Mello Alves Rodrigues

Full Text Available ABSTRACT Introduction: The specificity of sports training can lead to muscle specialization with a possible change in the natural hamstring/quadriceps torque ratio (HQ ratio, constituting a risk factor for muscle injury at the joint angles in which muscle imbalance may impair dynamic stability. Objective: The aim was to evaluate the torque distribution of the hamstrings and quadriceps and the HQ ratio throughout the range of motion in order to identify possible muscle imbalances at the knee of female futsal athletes. Methods: Nineteen amateur female futsal athletes had their dominant limb HQ ratio evaluated in a series of five maximum repetitions of flexion/extension of the knee at 180°/second in the total joint range of motion (30° to 80°. The peak flexor and extensor torque and the HQ ratio (% were compared each 5° of knee motion using one-way repeated measures ANOVA and Tukey’s post hoc test (p<0.05 to determine the joint angles that present muscular imbalance. Results: Quadriceps torque was higher than 50° to 60° of knee flexion, while hamstrings torque was higher than 55° to 65°. The HQ ratio presented lower values than 30° to 45° of knee flexion and four athletes presented values lower than 60%, which may represent a risk of injury. However, the HQ ratio calculated by the peak torque showed only one athlete with less than 60%. Conclusion: The HQ ratio analyzed throughout the knee range of motion allowed identifying muscle imbalance at specific joint angles in female futsal players.

Knee Flexion and Daily Activities in Patients following Total Knee Replacement: A Comparison with ISO Standard 14243

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Markus A. Wimmer

2015-01-01

Full Text Available Walking is only one of many daily activities performed by patients following total knee replacement (TKR. The purpose of this study was to examine the hypotheses (a that subject activity characteristics are correlated with knee flexion range of motion (ROM and (b that there is a significant difference between the subject’s flexion/extension excursion throughout the day and the ISO specified input for knee wear testing. In order to characterize activity, the number of walking and stair stepping cycles, the time spent with dynamic and stationary activities, the number of activity sequences, and the knee flexion/extension excursion of 32 TKR subjects were collected during daily activity. Flexion/extension profiles were compared with the ISO 14243 simulator input profile using a level crossing classification algorithm. Subjects took an average of 3102 (range: 343–5857 walking cycles including 65 (range: 0–319 stair stepping cycles. Active and passive ROMs were positively correlated with stair walking time, stair step counts, and stair walking sequences. Simulated knee motion according to ISO showed significantly fewer level crossings at the flexion angles 20–40° and beyond 50° than those measured with the monitor. This suggests that implant wear testing protocols should contain more cycles and a variety of activities requiring higher knee flexion angles with incorporated resting/transition periods to account for the many activity sequences.

Interdependence of torque, joint angle, angular velocity and muscle action during human multi-joint leg extension.

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Hahn, Daniel; Herzog, Walter; Schwirtz, Ansgar

2014-08-01

Force and torque production of human muscles depends upon their lengths and contraction velocity. However, these factors are widely assumed to be independent of each other and the few studies that dealt with interactions of torque, angle and angular velocity are based on isolated single-joint movements. Thus, the purpose of this study was to determine force/torque-angle and force/torque-angular velocity properties for multi-joint leg extensions. Human leg extension was investigated (n = 18) on a motor-driven leg press dynamometer while measuring external reaction forces at the feet. Extensor torque in the knee joint was calculated using inverse dynamics. Isometric contractions were performed at eight joint angle configurations of the lower limb corresponding to increments of 10° at the knee from 30 to 100° of knee flexion. Concentric and eccentric contractions were performed over the same range of motion at mean angular velocities of the knee from 30 to 240° s(-1). For contractions of increasing velocity, optimum knee angle shifted from 52 ± 7 to 64 ± 4° knee flexion. Furthermore, the curvature of the concentric force/torque-angular velocity relations varied with joint angles and maximum angular velocities increased from 866 ± 79 to 1,238 ± 132° s(-1) for 90-50° knee flexion. Normalised eccentric forces/torques ranged from 0.85 ± 0.12 to 1.32 ± 0.16 of their isometric reference, only showing significant increases above isometric and an effect of angular velocity for joint angles greater than optimum knee angle. The findings reveal that force/torque production during multi-joint leg extension depends on the combined effects of angle and angular velocity. This finding should be accounted for in modelling and optimisation of human movement.

An extension theory-based maximum power tracker using a particle swarm optimization algorithm

International Nuclear Information System (INIS)

Chao, Kuei-Hsiang

2014-01-01

Highlights: • We propose an adaptive maximum power point tracking (MPPT) approach for PV systems. • Transient and steady state performances in tracking process are improved. • The proposed MPPT can automatically tune tracking step size along a P–V curve. • A PSO algorithm is used to determine the weighting values of extension theory. - Abstract: The aim of this work is to present an adaptive maximum power point tracking (MPPT) approach for photovoltaic (PV) power generation system. Integrating the extension theory as well as the conventional perturb and observe method, an maximum power point (MPP) tracker is made able to automatically tune tracking step size by way of the category recognition along a P–V characteristic curve. Accordingly, the transient and steady state performances in tracking process are improved. Furthermore, an optimization approach is proposed on the basis of a particle swarm optimization (PSO) algorithm for the complexity reduction in the determination of weighting values. At the end of this work, a simulated improvement in the tracking performance is experimentally validated by an MPP tracker with a programmable system-on-chip (PSoC) based controller

Voluntary drive-dependent changes in vastus lateralis motor unit firing rates during a sustained isometric contraction at 50% of maximum knee extension force.

NARCIS (Netherlands)

de Ruiter, C.J.; Elzinga, M.J.; Verdijk, PW; van Mechelen, W.; de Haan, A.

2004-01-01

The purpose of the present study was to relate the expected inter-subject variability in voluntary drive of the knee extensor muscles during a sustained isometric contraction to the changes in firing rates of single motor units. Voluntary activation, as established with super-imposed electrical

The effect of a knee ankle foot orthosis incorporating an active knee mechanism on gait of a person with poliomyelitis.

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Arazpour, Mokhtar; Chitsazan, Ahmad; Bani, Monireh Ahmadi; Rouhi, Gholamreza; Ghomshe, Farhad Tabatabai; Hutchins, Stephen W

2013-10-01

The aim of this case study was to identify the effect of a powered stance control knee ankle foot orthosis on the kinematics and temporospatial parameters of walking by a person with poliomyelitis when compared to a knee ankle foot orthosis. A knee ankle foot orthosis was initially manufactured by incorporating drop lock knee joints and custom molded ankle foot orthoses and fitted to a person with poliomyelitis. The orthosis was then adapted by adding electrically activated powered knee joints to provide knee extension torque during stance and also flexion torque in swing phase. Lower limb kinematic and kinetic data plus data for temporospatial parameters were acquired from three test walks using each orthosis. Walking speed, step length, and vertical and horizontal displacement of the pelvis decreased when walking with the powered stance control knee ankle foot orthosis compared to the knee ankle foot orthosis. When using the powered stance control knee ankle foot orthosis, the knee flexion achieved during swing and also the overall pattern of walking more closely matched that of normal human walking. The reduced walking speed may have caused the smaller compensatory motions detected when the powered stance control knee ankle foot orthosis was used. The new powered SCKAFO facilitated controlled knee flexion and extension during ambulation for a volunteer poliomyelitis person.

How does knee pain affect trunk and knee motion during badminton forehand lunges?

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Huang, Ming-Tung; Lee, Hsing-Hsan; Lin, Cheng-Feng; Tsai, Yi-Ju; Liao, Jen-Chieh

2014-01-01

Badminton requires extensive lower extremity movement and a precise coordination of the upper extremity and trunk movements. Accordingly, this study investigated motions of the trunk and the knee, control of dynamic stability and muscle activation patterns of individuals with and without knee pain. Seventeen participants with chronic knee pain and 17 healthy participants participated in the study and performed forehand forward and backward diagonal lunges. This study showed that those with knee pain exhibited smaller knee motions in frontal and horizontal planes during forward lunge but greater knee motions in sagittal plane during backward lunge. By contrast, in both tasks, the injured group showed a smaller value on the activation level of the paraspinal muscles in pre-impact phase, hip-shoulder separation angle, trunk forward inclination range and peak centre of mass (COM) velocity. Badminton players with knee pain adopt a more conservative movement pattern of the knee to minimise recurrence of knee pain. The healthy group exhibit better weight-shifting ability due to a greater control of the trunk and knee muscles. Training programmes for badminton players with knee pain should be designed to improve both the neuromuscular control and muscle strength of the core muscles and the knee extensor with focus on the backward lunge motion.

Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

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Niitsu, M.; Itai, Y. [Department of Radiology, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan); Ikeda, K. [Department of Orthopedic Surgery, Institute of Clinical Medicine, University of Tsukuba, Tennodai, Tsukuba, Ibaraki 305 (Japan)

1998-02-01

The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.) With 3 figs., 1 tab., 6 refs.

Slightly flexed knee position within a standard knee coil: MR delineation of the anterior cruciate ligament

International Nuclear Information System (INIS)

Niitsu, M.; Itai, Y.; Ikeda, K.

1998-01-01

The purpose of this study was to assess the value of positioning the knee slightly flexed within a standard MR knee coil in delineation of the anterior cruciate ligament (ACL). Within the confined space of a commercially available knee coil, knee could bend as much as 30 , average 17 of flexion. Sets of oblique sagittal MR images were obtained at both fully extended and slightly flexed positions. Twenty-two normal knees and 18 knees with ACL tears were examined and paired MR images were evaluated by two observers. Compared with knee extension, the MR images for knee flexion provided better clarity in 57 % of reviews of full length of the ACL and 53 % of the femoral attachment. In the extended position the anterior margin of the ligament was obscured due to partial averaging with the intercondylar roof. We recommend examining the knee in an achievable flexed position within the standard knee coil. (orig.)

Mechanical factors relate to pain in knee osteoarthritis.

Science.gov (United States)

Maly, Monica R; Costigan, Patrick A; Olney, Sandra J

2008-07-01

Pain experienced by people with knee osteoarthritis is related to psychosocial factors and damage to articular tissues and/or the pain pathway itself. Mechanical factors have been speculated to trigger this pain experience; yet mechanics have not been identified as a source of pain in this population. The purpose of this study was to identify whether mechanics could explain variance in pain intensity in people with knee osteoarthritis. Data from 53 participants with physician-diagnosed knee osteoarthritis (mean age=68.5 years; standard deviation=8.6 years) were analyzed. Pain intensity was reported on the Western Ontario and McMaster Universities Osteoarthritis Index. Mechanical measures included weight-bearing varus-valgus alignment, body mass index and isokinetic quadriceps torque. Gait analysis captured the range of adduction-abduction angle, range of flexion-extension angle and external knee adduction moment during level walking. Pain intensity was significantly related to the dynamic range of flexion-extension during gait and body mass index. A total of 29% of the variance in pain intensity was explained by mechanical variables. The range of flexion-extension explained 18% of variance in pain intensity. Body mass index added 11% to the model. The knee adduction moment was unrelated to pain intensity. The findings support that mechanical factors are related to knee osteoarthritis pain. Because limitations in flexion-extension range of motion and body size are modifiable factors, future research could examine whether interventions targeting these mechanics would facilitate pain management.

Whole-body vibration does not influence knee joint neuromuscular function or proprioception.

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Hannah, R; Minshull, C; Folland, J P

2013-02-01

This study examined the acute effects of whole-body vibration (WBV) on knee joint position sense and indices of neuromuscular function, specifically strength, electromechanical delay and the rate of force development. Electromyography and electrically evoked contractions were used to investigate neural and contractile responses to WBV. Fourteen healthy males completed two treatment conditions on separate occasions: (1) 5 × 1 min of unilateral isometric squat exercise on a synchronous vibrating platform [30 Hz, 4 mm peak-to-peak amplitude] (WBV) and (2) a control condition (CON) of the same exercise without WBV. Knee joint position sense (joint angle replication task) and quadriceps neuromuscular function were assessed pre-, immediately-post and 1 h post-exercise. During maximum voluntary knee extensions, the peak force (PF(V)), electromechanical delay (EMD(V)), rate of force development (RFD(V)) and EMG of the quadriceps were measured. Twitch contractions of the knee extensors were electrically evoked to assess EMD(E) and RFD(E). The results showed no influence of WBV on knee joint position, EMD(V), PF(V) and RFD(V) during the initial 50, 100 or 150 ms of contraction. Similarly, electrically evoked neuromuscular function and neural activation remained unchanged following the vibration exercise. A single session of unilateral WBV did not influence any indices of thigh muscle neuromuscular performance or knee joint proprioception. © 2011 John Wiley & Sons A/S.

Elemental composition of cosmic rays using a maximum likelihood method

International Nuclear Information System (INIS)

Ruddick, K.

1996-01-01

We present a progress report on our attempts to determine the composition of cosmic rays in the knee region of the energy spectrum. We have used three different devices to measure properties of the extensive air showers produced by primary cosmic rays: the Soudan 2 underground detector measures the muon flux deep underground, a proportional tube array samples shower density at the surface of the earth, and a Cherenkov array observes light produced high in the atmosphere. We have begun maximum likelihood fits to these measurements with the hope of determining the nuclear mass number A on an event by event basis. (orig.)

Effect of hip and knee position on nerve conduction in the common fibular nerve.

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Broadhurst, Peter Kaas; Robinson, Lawrence R

2017-09-01

The aim of this study was to measure the influence that hip and knee position have on routine fibular motor nerve conduction studies. Healthy subjects under age 40 were recruited (n = 24) to have fibular nerve conduction studies completed in various positions, using hip extension-knee extension as a control. A mean increase in conduction velocity of 2.5 m/s across the knee (P = 0.020) was seen during hip flexion compared with hip extension. A mean decrease in velocity of 1.6 m/s through the leg segment (P = 0.016) was seen during knee flexion compared with knee extension. This study shows that the optimal position of the leg during fibular nerve studies is with the hip in flexion and knee in extension, to more accurately reflect nerve length for velocity calculations. This may have implications for other peripheral nerves with respect to proximal joint position affecting calculated velocity. Muscle Nerve 56: 519-521, 2017. © 2017 Wiley Periodicals, Inc.

The cyclops lesion after bicruciate-retaining total knee replacement

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Mark A. Klaassen, MD, FACS

2017-12-01

Full Text Available The cyclops lesion is a localized anterior arthrofibrosis most commonly seen following anterior cruciate ligament reconstruction. The lesion forms at the anterior cruciate ligament insertion creating a painful extension block between femoral intercondylar notch and tibial plateau. We present 2 cases (3 knees in which cyclops lesions appeared atypically following bicruciate-retaining total knee replacement. Two lesions occurred in a single patient following bilateral knee replacement. One lesion occurred in an active sportswoman. All 3 resolved following arthroscopic debridement. We describe the presentation of this unusual complication and suggest keys to its diagnosis, treatment, and prevention. Keywords: Cyclops lesion, Bicruciate-retaining, Total knee arthroplasty, Extension deficit

Quadriceps strength and anterior knee pain following tibia ...

African Journals Online (AJOL)

The tension generated on extension of the knee against a resistance using tensiometer was measured in Newton. The ranges of motion of the knees were documented, as well as Lysholm score which measures activities and document the presence and limitation caused by anterior knee pain. Results: A total of 36 patients ...

[Surgical technique and clinical results of total knee arthroplasty in treating endstage gonarthrosis combined with valgus knee deformity].

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Wang, Xingshan; Weng, Xisheng; Lin, Jin; Jin, Jin; Qian, Wenwei

2012-05-01

To investigate the surgical technique and the clinical results of total knee arthroplasty (TKA) in treating end-stage gonarthrosis combined with valgus knee deformity. Between November 1998 and October 2010, 64 patients (72 knees) with end-stage gonarthrosis combined with valgus knee deformity underwent TKA by a medial parapatellar approach. Of the 64 patients, 18 were male and 46 were female with an average age of 62.5 years (range, 23-82 years), including 44 cases (49 knees) of osteoarthritis, 17 cases (20 knees) of rheumatoid arthritis, 2 cases (2 knees) of haemophilic arthritis, and 1 case (1 knee) of post-traumatic arthritis. Bilateral knees were involved in 8 cases, and single knee in 56 cases. The flexion and extension range of motion (ROM) of the knee joint was (82.2 +/- 28.7) degrees; the femur-tibia angle (FTA) was (18.0 +/- 5.8) degrees; according to Knee Society Score (KSS) criterion, the preoperative clinical score was 31.2 +/- 10.1 and functional score was 37.3 +/- 9.0. According to Krackow's classification, there were 65 knees of type I and 7 knees of type II. By medial parapatellar approach, conventional osteotomy and Ranawat soft tissue release were performed in all cases. Prosthesis of preserved posterior cruciate ligament were used in 7 cases (7 knees), posterior stabilize prosthesis in 54 cases (60 knees), constrained prosthesis in 4 cases (5 knees). Incisions healed by first intention in all cases. Peroneal nerve palsy occurred in 1 patient with haemophilic arthritis, severe valgus deformity (FTA was 41 degrees), and flexion contracture (20 degrees), which was cured after 1 year of conservative treatment. Revison surgery was performed in 1 case of deep infection at 2 years after surgery. All the patients were followed up 4.9 years on average (range, 1-13 years). At last follow-up, the FTA was (7.0 +/- 2.5) degrees, showing significant difference when compared with preoperative value (t = 15.502, P = 0.000). The KSS clinical score was 83.0 +/- 6

A lower-extremity exoskeleton improves knee extension in children with crouch gait from cerebral palsy.

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Lerner, Zachary F; Damiano, Diane L; Bulea, Thomas C

2017-08-23

The ability to walk contributes considerably to physical health and overall well-being, particularly in children with motor disability, and is therefore prioritized as a rehabilitation goal. However, half of ambulatory children with cerebral palsy (CP), the most prevalent childhood movement disorder, cease to walk in adulthood. Robotic gait trainers have shown positive outcomes in initial studies, but these clinic-based systems are limited to short-term programs of insufficient length to maintain improved function in a lifelong disability such as CP. Sophisticated wearable exoskeletons are now available, but their utility in treating childhood movement disorders remains unknown. We evaluated an exoskeleton for the treatment of crouch (or flexed-knee) gait, one of the most debilitating pathologies in CP. We show that the exoskeleton reduced crouch in a cohort of ambulatory children with CP during overground walking. The exoskeleton was safe and well tolerated, and all children were able to walk independently with the device. Rather than guiding the lower limbs, the exoskeleton dynamically changed the posture by introducing bursts of knee extension assistance during discrete portions of the walking cycle, a perturbation that resulted in maintained or increased knee extensor muscle activity during exoskeleton use. Six of seven participants exhibited postural improvements equivalent to outcomes reported from invasive orthopedic surgery. We also demonstrate that improvements in crouch increased over the course of our multiweek exploratory trial. Together, these results provide evidence supporting the use of wearable exoskeletons as a treatment strategy to improve walking in children with CP. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

Comparison of proximally versus distally placed spatially distributed sequential stimulation electrodes in a dynamic knee extension task

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Marco Laubacher

2016-06-01

Full Text Available Spatially distributed sequential stimulation (SDSS has demonstrated substantial power output and fatigue benefits compared to single electrode stimulation (SES in the application of functional electrical stimulation (FES. This asymmetric electrode setup brings new possibilities but also new questions since precise placement of the electrodes is one critical factor for good muscle activation. The aim of this study was to compare the power output, fatigue and activation properties of proximally versus distally placed SDSS electrodes in an isokinetic knee extension task simulating knee movement during recumbent cycling. M. vastus lateralis and medialis of seven able-bodied subjects were stimulated with rectangular bi-phasic pulses of constant amplitude of 40 mA and at an SDSS frequency of 35 Hz for 6 min on both legs with both setups (i.e. n=14. Torque was measured during knee-extension movement by a dynamometer at an angular velocity of 110 deg/s. Mean power, peak power and activation time were calculated and compared for the initial and final stimulation phases, together with an overall fatigue index. Power output values (Pmean, Ppeak were scaled to a standardised reference input pulse width of 100 μs (Pmean,s, Ppeak,s. The initial evaluation phase showed no significant differences between the two setups for all outcome measures. Ppeak and Ppeak,s were both significantly higher in the final phase for the distal setup (25.4 ± 8.1 W vs. 28.2 ± 6.2 W, p=0.0062 and 34.8 ± 9.5 W vs. 38.9 ± 6.7 W, p=0.021, respectively. With distal SDSS, there was modest evidence of higher Pmean and Pmean,s (p=0.071, p=0.14, respectively but of longer activation time (p=0.096. The rate of fatigue was similar for both setups. For practical FES applications, distal placement of the SDSS electrodes is preferable.

Noncircular Chainrings Do Not Influence Maximum Cycling Power.

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Leong, Chee-Hoi; Elmer, Steven J; Martin, James C

2017-12-01

Noncircular chainrings could increase cycling power by prolonging the powerful leg extension/flexion phases, and curtailing the low-power transition phases. We compared maximal cycling power-pedaling rate relationships, and joint-specific kinematics and powers across 3 chainring eccentricities (CON = 1.0; LOW ecc  = 1.13; HIGH ecc  = 1.24). Part I: Thirteen cyclists performed maximal inertial-load cycling under 3 chainring conditions. Maximum cycling power and optimal pedaling rate were determined. Part II: Ten cyclists performed maximal isokinetic cycling (120 rpm) under the same 3 chainring conditions. Pedal and joint-specific powers were determined using pedal forces and limb kinematics. Neither maximal cycling power nor optimal pedaling rate differed across chainring conditions (all p > .05). Peak ankle angular velocity for HIGH ecc was less than CON (p pedal system allowed cyclists to manipulate ankle angular velocity to maintain their preferred knee and hip actions, suggesting maximizing extension/flexion and minimizing transition phases may be counterproductive for maximal power.

[Clinical effect of total knee arthroplasty on patients with knee osteoarthritis combined with mild to moderate valgus knee deformity].

Science.gov (United States)

Chen, Peng; Zeng, Min; Xie, Jie; Wang, Long; Su, Weiping; Hu, Yihe

2016-09-28

To investigate the clinical effect of total knee arthroplasty on patients with knee osteoarthritis combined with mild to moderate valgus knee deformity.
 A total of 15 patients received total knee arthroplasty for correcting mild (10°-15°) to moderate (15°-30°) valgus knee between January 2011 and February 2014 in Xiangya Hospital of Central South University. We adopted a stable prosthesis surgery through patellar medial approach, osteophytes cleaning, conventional osteotomy, a selective soft tissue release and balance technical correcting of knee valgus deformity. Then conventional anticoagulation and symptomatic rehabilitation was utilized. Preoperative and postoperative X-ray was conducted in patients with measuring femor-tibial angle (FTA) and inspecting the prosthesis position. FTA, visual analog scale (VAS) standard, and parallel knee scoring system (KSS) were used to evaluate the clinical effect.
 Fifteen patients were followed up for 14 to 36 (22.40±11.88) months. The hospitalization time was 7-13 (7.73±1.58) d; operative time was 58-110 (81.8±16.85) min, the dominant blood loss was 140-600 (337.30±143.65) mL. Two cases had knee extension hysteresis, and the knee activity recovered after exercise. Leg power lines were normal. Three postoperative cases suffered anterior knee pain. They were subjected to celecoxib analgesic treatment and the pain gradually eased after 3 months. One postoperative case showed incision discharge and swelling, which was healed after change of dressing. During follow-up, review of X-ray film does not show prosthesis loose, subsidence and other complications. The knee valgus angle (8.1±1.8)°, knee motion range (107.33±9.61)°, KSS knee score (74.7±14.5, 75.3±2.7) and pain score (2.5±0.9) were significantly better than the preoperative (Pclinical and function KSS scores showed that the improvement rate was 80%. 
 Total knee arthroplasty is an effective way to treat patients with knee osteoarthritis combined with

In vivo six-degree-of-freedom knee-joint kinematics in overground and treadmill walking following total knee arthroplasty.

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Guan, Shanyuanye; Gray, Hans A; Schache, Anthony G; Feller, Julian; de Steiger, Richard; Pandy, Marcus G

2017-08-01

No data are available to describe six-degree-of-freedom (6-DOF) knee-joint kinematics for one complete cycle of overground walking following total knee arthroplasty (TKA). The aims of this study were firstly, to measure 6-DOF knee-joint kinematics and condylar motion for overground walking following TKA; and secondly, to determine whether such data differed between overground and treadmill gait when participants walked at the same speed during both tasks. A unique mobile biplane X-ray imaging system enabled accurate measurement of 6-DOF TKA knee kinematics during overground walking by simultaneously tracking and imaging the joint. The largest rotations occurred for flexion-extension and internal-external rotation whereas the largest translations were associated with joint distraction and anterior-posterior drawer. Strong associations were found between flexion-extension and adduction-abduction (R 2  = 0.92), joint distraction (R 2  = 1.00), and anterior-posterior translation (R 2  = 0.77), providing evidence of kinematic coupling in the TKA knee. Although the measured kinematic profiles for overground walking were grossly similar to those for treadmill walking, several statistically significant differences were observed between the two conditions with respect to temporo-spatial parameters, 6-DOF knee-joint kinematics, and condylar contact locations and sliding. Thus, caution is advised when making recommendations regarding knee implant performance based on treadmill-measured knee-joint kinematic data. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:1634-1643, 2017. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

Sidestep cutting technique and knee abduction loading: implications for ACL prevention exercises.

Science.gov (United States)

Kristianslund, Eirik; Faul, Oliver; Bahr, Roald; Myklebust, Grethe; Krosshaug, Tron

2014-05-01

Sidestep cutting technique is essential in programmes to prevent anterior cruciate ligament (ACL) injury. A better understanding of how technique affects potentially harmful joint loading may improve prevention programmes. The purpose of this study was to investigate the effect of sidestep cutting technique on maximum knee abduction moments. Cross-sectional study. Whole-body kinematics and knee joint kinetics were calculated in 123 female handball players (mean±SD, 22.5±7.0 years, 171±7 cm, 67±7 kg) performing sidestep cutting. Three cuts from each side were analysed. Linear regression was applied between selected technique factors and maximum knee abduction moment during the first 100 ms of the contact phase. Furthermore, we investigated to what degree the abduction moment originated from the magnitude of the ground reaction force (GRF) or the knee abduction moment arm of the GRF. Technique factors explained 62% of the variance in knee abduction moments. Cut width, knee valgus, toe landing, approach speed and cutting angle were the most significant predictors. An increase in one of these factors of 1 SD increased the knee abduction moment from 12% to 19%. The effect of the moment arm of the GRF was more important than the force magnitude for maximum knee abduction moments. Lower knee abduction loads during sidestep cutting may be achieved if cuts are performed as narrow cuts with low knee valgus and toe landings. These factors may be targeted in ACL injury prevention programmes.

Techniques for assessing knee joint pain in arthritis

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Fu Yu

2007-03-01

Full Text Available Abstract The assessment of pain is of critical importance for mechanistic studies as well as for the validation of drug targets. This review will focus on knee joint pain associated with arthritis. Different animal models have been developed for the study of knee joint arthritis. Behavioral tests in animal models of knee joint arthritis typically measure knee joint pain rather indirectly. In recent years, however, progress has been made in the development of tests that actually evaluate the sensitivity of the knee joint in arthritis models. They include measurements of the knee extension angle struggle threshold, hind limb withdrawal reflex threshold of knee compression force, and vocalizations in response to stimulation of the knee. A discussion of pain assessment in humans with arthritis pain conditions concludes this review.

Differential glucose uptake in quadriceps and other leg muscles during one-legged dynamic submaximal knee-extension exercise

DEFF Research Database (Denmark)

Kalliokoski, Kari K; Boushel, Robert; Langberg, Henning

2011-01-01

One-legged dynamic knee-extension exercise (DKE) is a widely used model to study the local cardiovascular and metabolic responses to exercise of the quadriceps muscles. In this study, we explored the extent to which different muscles of the quadriceps are activated during exercise using positron...... emission tomography (PET) determined uptake of [18F]-fluoro-deoxy-glucose (GU) during DKE. Five healthy male subjects performed DKE at 25 W for 35 min and both the contracting and contralateral resting leg were scanned with PET from mid-thigh and distally. On average, exercise GU was the highest...

Knee flexion contractures in institutionalized elderly: prevalence, severity, stability, and related variables.

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Mollinger, L A; Steffen, T M

1993-07-01

The purpose of this study was to document the prevalence, severity, and progression of knee flexion contractures (KFCs) in a population of institutionalized elderly and to identify relationships between knee extension and other variables. The subjects were 112 nursing home residents who exhibited a broad range of ambulation and cognitive function abilities. Data were collected initially (T1) and after a 10-month period (T2). Only 25% of the population had extension in the 0- to 5-degree (lacking full extension) range bilaterally at T1 and T2, leaving the majority of subjects with some degree of unilateral KFC. Most of the subjects with a KFC greater than 20 degrees were nonambulatory and had a significantly higher occurrence of resistance to motion than did nonambulators with a KFC of less than 20 degrees. Knee extension measurements did not change in most subjects between T1 and T2. The knees that did show a change in KFC (either an increase or a decrease) had a significantly higher occurrence of resistance to passive motion than did other knees. Compared with the subjects who gained extension, the subjects who lost extension over the study period more frequently had minimal KFC at T1, were ambulatory at T1, showed a regression in ambulation at T2, and developed resistance to motion at T2. The data confirmed significant positive correlations between degree of KFC and presence of resistance to passive knee motion, cognitive impairment, impaired ambulation, and presence of knee pain. Physical therapy assessment and intervention may be appropriate in nonambulatory nursing home residents with resistance to passive motion, residents with KFC approaching 20 degrees, and ambulatory residents with minimal KFC who develop resistance and begin to regress in ambulation. Several areas for future study are suggested.

Six degree-of-freedom knee joint kinematics in obese individuals with knee pain during gait.

Science.gov (United States)

Li, Jing-Sheng; Tsai, Tsung-Yuan; Felson, David T; Li, Guoan; Lewis, Cara L

2017-01-01

Knee joint pain is a common symptom in obese individuals and walking is often prescribed as part of management programs. Past studies in obese individuals have focused on standing alignment and kinematics in the sagittal and coronal planes. Investigation of 6 degree-of-freedom (6DOF) knee joint kinematics during standing and gait is important to thoroughly understand knee function in obese individuals with knee pain. This study aimed to investigate the 6DOF knee joint kinematics in standing and during gait in obese patients using a validated fluoroscopic imaging system. Ten individuals with obesity and knee pain were recruited. While standing, the knee was in 7.4±6.3°of hyperextension, 2.8±3.3° of abduction and 5.6±7.3° of external rotation. The femoral center was located 0.7±3.1mm anterior and 5.1±1.5mm medial to the tibial center. During treadmill gait, the sagittal plane motion, i.e., flexion/extension and anterior-posterior translation, showed a clear pattern. Specifically, obese individuals with knee pain maintained the knee in more flexion and more anterior tibial translation during most of the stance phase of the gait cycle and had a reduced total range of knee flexion when compared to a healthy non-obese group. In conclusion, obese individuals with knee pain used hyperextension knee posture while standing, but maintained the knee in more flexion during gait with reduced overall range of motion in the 6DOF analysis.

Is the modified Tardieu scale in semi-standing position better associated with knee extension and hamstring activity in terminal swing than the supine Tardieu?

NARCIS (Netherlands)

Faber, I.R.; Nienhuis, B.; Rijs, N.P.; Geurts, A.C.H.; Duysens, J.E.J.

2008-01-01

The aim of this study was to investigate whether the modified Tardieu scale (MTS) in a semi-standing position, used for the assessment of hamstrings spasticity, was better associated with knee extension and hamstrings activity in terminal swing than the MTS in a supine position in children with

LONG-STANDING UNREDUCED ANTERIOR DISLOCATION OF THE KNEE - A CASE REPORT

Directory of Open Access Journals (Sweden)

Dr. Navin Kumar Karn

2010-01-01

Full Text Available A case of long standing unreduced anterior dislocation of the knee for 2 months has been reported which was treated first with open reduction and external fixation at 70° flexion of knee followed by gradual extension of knee. Once full extension was achieved, the cylindrical cast was applied for 3 months. The final range of movement of knee at one year follow up was 5-70º along with painless weight bearing. To conclude, this conservative treatment could be one of the valuable option for the patients who can not undergo major surgery because of genreral health problem, or unable to afford for the surgery especially in developing countries, or not willing for arthrodesis.

Total knee replacement influences both knee and hip joint kinematics during stair climbing

OpenAIRE

Saari, Tuuli; Tranberg, Roy; Zügner, Roland; Uvehammer, Johan; Kärrholm, Johan

2004-01-01

A gait analysis system was used to evaluate the kinematics of the hip and knee during stair ascending and descending after operation with total knee replacement. Patients with 5° varus/valgus alignment or less were selected randomly to receive either a flat or a concave tibial component with retention of the posterior cruciate ligament. Patients who had more than 5° varus/valgus alignment and/or an extension defect of 10° or more were selected randomly to receive the concave or posterior-stab...

The effect of knee extensor open kinetic chain resistance training in the ACL-injured knee.

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Barcellona, Massimo G; Morrissey, Matthew C; Milligan, Peter; Clinton, Melissa; Amis, Andrew A

2015-11-01

To investigate the effect of different loads of knee extensor open kinetic chain resistance training on anterior knee laxity and function in the ACL-injured (ACLI) knee. Fifty-eight ACLI subjects were randomised to one of three (12-week duration) training groups. The STAND group trained according to a standardised rehabilitation protocol. Subjects in the LOW and HIGH group trained as did the STAND group but with the addition of seated knee extensor open kinetic chain resistance training at loads of 2 sets of 20 repetition maximum (RM) and 20 sets of 2RM, respectively. Anterior knee laxity and measurements of physical and subjective function were performed at baseline, 6 and 12 weeks. Thirty-six subjects were tested at both baseline and 12 weeks (STAND n = 13, LOW n = 11, HIGH n = 12). The LOW group demonstrated a reduction in 133 N anterior knee laxity between baseline and 12 weeks testing when compared to the HIGH and the STAND groups (p = 0.009). Specifically, the trained-untrained knee laxity decreased an average of approximately 5 mm in the LOW group while remaining the same in the other two groups. Twelve weeks of knee extensor open kinetic chain resistance training at loads of 2 sets of 20RM led to a reduction in anterior knee laxity in the ACLI knee. This reduction in laxity does not appear to offer any significant short-term functional advantages when compared to a standard rehabilitation protocol. These results indicate that knee laxity can be decreased with resistance training of the thigh muscles. Randomised controlled trial, Level II.

No exacerbation of knee joint pain and effusion following preoperative progressive resistance training in patients scheduled for total knee arthroplasty

DEFF Research Database (Denmark)

Skoffer, Birgit; Dalgas, Ulrik; Maribo, Thomas

2017-01-01

BACKGROUND: Preoperative progressive resistance training (PRT) is controversial in patients scheduled for total knee arthroplasty (TKA), because of the concern that it may exacerbate knee joint pain and effusion. OBJECTIVE: To examine if preoperative PRT initiated 5 weeks prior to TKA would 1......) exacerbate pain and knee effusion, 2) allow a progressively increased training load throughout the training period that would subsequently increase muscle strength. DESIGN: Secondary analyses from a randomized controlled trial. SETTING: University Hospital and a Regional Hospital. PATIENTS: Thirty patients...... OUTCOME MEASURES: Before and after each training session, knee joint pain rated on an 11-point scale, effusion assessed by measuring the knee joint circumference, and training load were recorded. The first and last training session were initiated by 1RM testing of unilateral leg press, knee extension...

Ultrasound monitoring of inter-knee distances during gait.

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Lai, Daniel T H; Wrigley, Tim V; Palaniswami, M

2009-01-01

Knee osteoarthritis is an extremely common, debilitating disease associated with pain and loss of function. There is considerable interest in monitoring lower limb alignment due to its close association with joint overload leading to disease progression. The effects of gait modifications that can lower joint loading are of particular interest. Here we describe an ultrasound-based system for monitoring an important aspect of dynamic lower limb alignment, the inter-knee distance during walking. Monitoring this gait parameter should facilitate studies in reducing knee loading, a primary risk factor of knee osteoarthritis progression. The portable device is composed of an ultrasound sensor connected to an Intel iMote2 equipped with Bluetooth wireless capability. Static tests and calibration results show that the sensor possesses an effective beam envelope of 120 degrees, with maximum distance errors of 10% at the envelope edges. Dynamic walking trials reveal close correlation of inter-knee distance trends between that measured by an optical system (Optotrak Certus NDI) and the sensor device. The maximum average root mean square error was found to be 1.46 cm. Future work will focus on improving the accuracy of the device.

A method for performance comparison of polycentric knees and its application to the design of a knee for developing countries.

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Anand, T S; Sujatha, S

2017-08-01

Polycentric knees for transfemoral prostheses have a variety of geometries, but a survey of literature shows that there are few ways of comparing their performance. Our objective was to present a method for performance comparison of polycentric knee geometries and design a new geometry. In this work, we define parameters to compare various commercially available prosthetic knees in terms of their stability, toe clearance, maximum flexion, and so on and optimize the parameters to obtain a new knee design. We use the defined parameters and optimization to design a new knee geometry that provides the greater stability and toe clearance necessary to navigate uneven terrain which is typically encountered in developing countries. Several commercial knees were compared based on the defined parameters to determine their suitability for uneven terrain. A new knee was designed based on optimization of these parameters. Preliminary user testing indicates that the new knee is very stable and easy to use. The methodology can be used for better knee selection and design of more customized knee geometries. Clinical relevance The method provides a tool to aid in the selection and design of polycentric knees for transfemoral prostheses.

Modelling knee flexion effects on joint power absorption and adduction moment.

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Nagano, Hanatsu; Tatsumi, Ichiroh; Sarashina, Eri; Sparrow, W A; Begg, Rezaul K

2015-12-01

Knee osteoarthritis is commonly associated with ageing and long-term walking. In this study the effects of flexing motions on knee kinetics during stance were simulated. Extended knees do not facilitate efficient loading. It was therefore, hypothesised that knee flexion would promote power absorption and negative work, while possibly reducing knee adduction moment. Three-dimensional (3D) position and ground reaction forces were collected from the right lower limb stance phase of one healthy young male subject. 3D position was sampled at 100 Hz using three Optotrak Certus (Northern Digital Inc.) motion analysis camera units, set up around an eight metre walkway. Force plates (AMTI) recorded ground reaction forces for inverse dynamics calculations. The Visual 3D (C-motion) 'Landmark' function was used to change knee joint positions to simulate three knee flexion angles during static standing. Effects of the flexion angles on joint kinetics during the stance phase were then modelled. The static modelling showed that each 2.7° increment in knee flexion angle produced 2.74°-2.76° increments in knee flexion during stance. Increased peak extension moment was 6.61 Nm per 2.7° of increased knee flexion. Knee flexion enhanced peak power absorption and negative work, while decreasing adduction moment. Excessive knee extension impairs quadriceps' power absorption and reduces eccentric muscle activity, potentially leading to knee osteoarthritis. A more flexed knee is accompanied by reduced adduction moment. Research is required to determine the optimum knee flexion to prevent further damage to knee-joint structures affected by osteoarthritis. Copyright © 2015 Elsevier B.V. All rights reserved.

A randomised clinical trial of the efficacy of drop squats or leg extension/leg curl exercises to treat clinically diagnosed jumper's knee in athletes: pilot study

Science.gov (United States)

Cannell, L; Taunton, J; Clement, D; Smith, C; Khan, K

2001-01-01

Objectives—To compare the therapeutic effect of two different exercise protocols in athletes with jumper's knee. Methods—Randomised clinical trial comparing a 12 week programme of either drop squat exercises or leg extension/leg curl exercises. Measurement was performed at baseline and after six and 12 weeks. Primary outcome measures were pain (visual analogue scale 1–10) and return to sport. Secondary outcome measures included quadriceps and hamstring moment of force using a Cybex II isokinetic dynamometer at 30°/second. Differences in pain response between the drop squat and leg extension/curl treatment groups were assessed by 2 (group) x 3 (time) analysis of variance. Two by two contingency tables were used to test differences in rates of return to sport. Analysis of variance (2 (injured versus non-injured leg) x 2 (group) x 3 (time)) was also used to determine differences for secondary outcome measures. Results—Over the 12 week intervention, pain diminished by 2.3 points (36%) in the leg extension/curl group and 3.2 points (57%) in the squat group. There was a significant main effect of both exercise protocols on pain (psquat group returned to sporting activity by 12 weeks, but five of those subjects still had low level pain. Six of nine of the leg extension/curl group returned to sporting activity by 12 weeks and four patients had low level pain. There was no significant difference between groups in numbers returning to sporting activity. There were no differences in the change in quadriceps or hamstring muscle moment of force between groups. Conclusions—Progressive drop squats and leg extension/curl exercises can reduce the pain of jumper's knee in a 12 week period and permit a high proportion of patients to return to sport. Not all patients, however, return to sport by that time. Key Words: knee; patellar tendon; tendinopathy; tendinosis; eccentric strengthening; strength training PMID:11157465

Electrode position markedly affects knee torque in tetanic, stimulated contractions.

Science.gov (United States)

Vieira, Taian M; Potenza, Paolo; Gastaldi, Laura; Botter, Alberto

2016-02-01

The purpose of this study was to investigate how much the distance between stimulation electrodes affects the knee extension torque in tetanic, electrically elicited contractions. Current pulses of progressively larger amplitude, from 0 mA to maximally tolerated intensities, were delivered at 20 pps to the vastus medialis, rectus femoris and vastus lateralis muscles of ten, healthy male subjects. Four inter-electrode distances were tested: 32.5% (L1), 45.0% (L2), 57.5% (L3) and 70% (L4) of the distance between the patella apex and the anterior superior iliac spine. The maximal knee extension torque and the current leading to the maximal torque were measured and compared between electrode configurations. The maximal current tolerated by each participant ranged from 60 to 100 mA and did not depend on the inter-electrode distance. The maximal knee extension torque elicited did not differ between L3 and L4 (P = 0.15) but, for both conditions, knee torque was significantly greater than for L1 and L2 (P torque elicited for L3 and L4 was two to three times greater than that obtained for L1 and L2. The current leading to maximal torque was not as sensitive to inter-electrode distance. Except for L1 current intensity did not change with electrode configuration (P > 0.16). Key results presented here revealed that for a given stimulation intensity, knee extension torque increased dramatically with the distance between electrodes. The distance between electrodes seems therefore to critically affect knee torque, with potential implication for optimising exercise protocols based on electrical stimulation.

Exercise-induced muscle fatigue in the unaffected knee joint and its influence on postural control and lower limb kinematics in stroke patients

Directory of Open Access Journals (Sweden)

Sun Wook Park

2017-01-01

Full Text Available This study aimed to investigate the effects of exercise-induced muscle fatigue in the unaffected knee joint on postural control and kinematic changes in stroke patients. Forty participants (20 stroke patients, 20 age-matched healthy participants were recruited. To induce fatigue, maximum voluntary isometric contractions were performed in the unaffected knee joint in a Leg Extension Rehab exercise machine using the pneumatic resistance. We measured static and dynamic balance and lower-limb kinematics during gait. Changes in postural control parameters anteroposterior sway speed and total center of pressure distance differed significantly between the stroke and control groups. In addition, changes in gait kinematic parameters knee and ankle angles of initial contact differed significantly between stroke (paretic and non-paretic and control groups. Muscle fatigue in the unaffected knee and ankle impaired postural control and debilitates kinematic movement of ipsilateral and contralateral lower limbs, and may place the fatigued stroke patients at greater risk for falls.

Exercise Alters Gait Pattern but Not Knee Load in Patients with Knee Osteoarthritis

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Ssu-Yu Chang

2016-01-01

Full Text Available Six female patients with bilateral medial knee OA and 6 healthy controls were recruited. Patients with knee OA received a 6-week physiotherapist-supervised and home-based exercise program. Outcome measures, including the Western Ontario and McMaster Universities Arthritis Index and Short Form-36 Health Survey as well as objective biomechanical indices were obtained at baseline and follow-up. After treatment, no significant difference was observed in the knee abductor moment (KAM, lever arm, and ground reaction force. We, however, observed significantly improved pain and physical function as well as altered gait patterns, including a higher hip flexor moment and hip extension angle with a faster walking speed. Although KAM was unchanged, patients with bilateral knee OA showed an improved walking speed and altered the gait pattern after 6 weeks of supervised exercise. This finding suggests that the exercise intervention improves proximal joint mechanics during walking and can be considered for patients with bilateral knee OA. Non-weight-bearing strengthening without external resistance combined with stretching exercise may be an option to improve pain and function in individuals with OA who cannot perform high resistance exercises owing to pain or other reasons.

FUNCTIONAL IMPROVEMENT UP TO SIX MONTHS AFTER TOTAL KNEE ARTHROPLASTY: MEASURED BY KNEE RANGE OF MOTION AND SELF-REPORTED QUESTIONNAIRE

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Mirjana Kocić

2015-12-01

Full Text Available The primary aim of this study was to assess knee range of motion (ROM as well as patients’ reported pain, stiffness and function up to six months after total knee arthroplasty (TKA. The secondary aim was to analyze the extent to which knee ROM correlates with patient-rated outcome. A prospective study included 60 patients with primary TKA for osteorthritis, admitted at Physical Medicine and Rehabilitation Clinic from April 2009 to October 2014. The patients were evaluated at 4 time points: at admission and at discharge, as well as at follow-up at 3 and at 6 months after surgery. The outcome parameters included: active knee ROM, as well as pain, stiffness and function according to self reported Western Ontario and McMaster Universities Osteoarthritis (WOMAC questionnaire. Statistically highly significant improvement in flexion and extension was observed from admission to all other assessment time points (p<0.001. Also, statistically significant improvement of all three WOMAC subscales (pain, stiffness and function was found between all assessments points (p<0.001. According to values of Spearman correlation coefficient, there was significant negative correlation of flexion with all WOMAC subscales at all assessment points, whereas correlation of extension with any assessed outcome parameter was without significance. It can be concluded that in TKA patients all outcome measures improved significantly from admission to 6 months follow-up. Knee flexion ROM negatively and moderately to strongly correlated with pain, stiffness and function, whereas correlation of extension with any assessed outcome measure was without significance.

ANALYSIS OF ISOKINETIC KNEE EXTENSION / FLEXION IN MALE ELITE ADOLESCENT WRESTLERS

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Sanli Sadi Kurdak

2005-12-01

Full Text Available Wrestling requires strength of the upper and lower body musculature which is critical for the athletic performance. Evaluation of the adolescent's skeletal muscle is important to understand body movement, especially including those involved in sports. Strength, power and endurance capacity are defined as parameters of skeletal muscle biomechanical properties. The isokinetic dynamometer is an important toll for making this type of evaluation. However, load range phase of range of motion has to be considered to interpret the data correctly. With this in mind we aimed to investigate the lover body musculature contractile characteristics of adolescent wrestlers together with detailed analyses of load range phase of motion. Thirteen boys aged 12 - 14 years participated to this study. Concentric load range torque, work and power of knee extension and flexion were measured by a Cybex Norm dynamometer at angular velocities from 450°/sec to 30°/sec with 30°/sec decrements for each set. None of the wrestlers were able to attain load range for angular velocities above 390°/sec and 420°/sec for extension and flexion respectively. Detailed analyses of the load range resulted in statistically significant differences in the normalized load range peak torque for extension at 270°/sec (1.44 ± 0.28 Nm·kg-1 and 1.14 ± 0.28 Nm·kg-1 for total and load range peak torque respectively, p < 0.05, and for flexion at 300°/sec (1.26 ± 0.28 Nm·kg-1 and 1.03 ± 0.23 Nm·kg-1 for total and load range peak torque respectively, p < 0.05, compared to total peak torque data. Similarly, the significant difference was found for the work values at 90°/sec (1.91 ± 0.23 Nm·kg-1 and 1.59 ± 0.24 Nm·kg-1 for total and load range work respectively for extension and 1.73 ± 0.21 Nm·kg-1 and 1.49 ± 0.19 Nm·kg-1 for total and load range work respectively for flexion, p < 0.05, and was evident at higher angular velocities (p < 0.001 for both extension and flexion. At

The cyclops lesion after bicruciate-retaining total knee replacement

OpenAIRE

Klaassen, Mark A.; Aikins, Jerry L.

2017-01-01

The cyclops lesion is a localized anterior arthrofibrosis most commonly seen following anterior cruciate ligament reconstruction. The lesion forms at the anterior cruciate ligament insertion creating a painful extension block between femoral intercondylar notch and tibial plateau. We present 2 cases (3 knees) in which cyclops lesions appeared atypically following bicruciate-retaining total knee replacement. Two lesions occurred in a single patient following bilateral knee replacement. One les...

Effect of Knee Orthoses on Hamstring Contracture in Children With Cerebral Palsy: Multiple Single-Subject Study.

Science.gov (United States)

Laessker-Alkema, Kristina; Eek, Meta Nyström

2016-01-01

To examine the effect of knee orthoses on extensibility of the hamstrings in children with spastic cerebral palsy (CP). The short-term effects of knee orthoses on passive range of motion (ROM), spasticity, and gross motor function of the hamstrings. Ten children with spastic CP, aged 5 to 14 years, at Gross Motor Function Classification System levels I to V, were followed. The orthoses were worn for a minimum of 30 minutes day, 5 days per week, during the intervention period of 8 weeks. Visual analysis using the Two Standard Deviation Band Method supported improvements in passive ROM for all 20 hamstring muscles and in 12 of 14 knee extension measurements. Analyses with the Wilcoxon signed rank test confirm the individual results and support a significant increase in hamstring muscles (P = .005) and knee extension (right: P =.028; left: P =.018) compared with baseline. In children with spastic CP, 8 weeks of treatment with knee orthoses can improve extensibility of the hamstrings.

Early recovery after fast-track Oxford unicompartmental knee arthroplasty

DEFF Research Database (Denmark)

Munk, Stig; Dalsgaard, Jesper; Bjerggaard, Karin

2012-01-01

trauma. We investigated changes in leg-extension power (LEP) in the first month after MIS Oxford UKA and its relation to pain, knee motion, functional performance, and knee function. Patients and methods In 35 consecutive Oxford UKA patients, LEP was measured 1 week before and 1 month after surgery...... together with knee motion, knee swelling, the 30-second chair-stand test, and Oxford knee score. Assessment of knee pain at rest and walking was done using a visual analog scale. Results 30 patients were discharged on the day after surgery, and 5 on the second day after surgery. LEP and functional...... performance reached the preoperative level after 1 month. Only slight postoperative knee swelling was observed with rapid restoration of knee flexion and function. A high level of pain during the first postoperative night and day fell considerably thereafter. None of the patients needed physiotherapy...

Does Knee Osteoarthritis Differentially Modulate Proprioceptive Acuity in the Frontal and Sagittal Planes of the Knee?

Science.gov (United States)

Cammarata, Martha L; Schnitzer, Thomas J; Dhaher, Yasin Y

2012-01-01

Objective Impaired proprioception may alter joint loading and contribute to the progression of knee osteoarthritis (OA). Though frontal plane loading at the knee contributes to OA, proprioception and its modulation with OA in this direction have not been examined. The aim of this study was to assess knee proprioceptive acuity in the frontal and sagittal planes in knee OA and healthy participants. We hypothesized that proprioceptive acuity will be decreased in the OA population in both planes of movement. Methods Thirteen persons with knee OA and fourteen healthy age-matched subjects participated. Proprioceptive acuity was assessed in varus, valgus, flexion, and extension using the threshold to detection of passive movement (TDPM). Repeated measures analysis of variance was used to assess differences in TDPM between subject groups and across movement directions. Linear regression analyses were performed to assess the correlation of TDPM between and within planes of movement. Results TDPM was found to be significantly higher (Pplanes of movement were only weakly correlated, especially in the OA group. Conclusions Consistent differences in TDPM between the OA and control groups across all movement directions suggest a global, not direction-specific, reduction in sensation in knee OA patients. PMID:21547895

Unusual Cause of Knee Locking

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Gazi Huri

2013-01-01

Full Text Available We report a case of partial intrasubstance tear of popliteus tendon as an unusual cause of pseudolocking of the knee. A 13-year-old semiprofessional soccer player applied to our clinic with a locked right knee in spite of the therapy applied (cold pack, NSAID, and immobilization in another institution 20 days after the injury. Significant extension loss was observed in his right knee with 30∘–90∘ ROM. Magnetic resonance imaging (MRI and arthroscopy confirmed the intrasubstance tear of popliteus tendon and synovitis. The ruptured part of the tendon was debrided, and the inflammatory tissue around the tendon, which may lead to pseudolocking, was gently removed with a shaver in order to regain the normal ROM. The patient was discharged with full ROM and weight bearing first day after the surgery. To our knowledge, this is the first case demonstrating intrasubstance tear of popliteus tendon causing pseudolocking of the knee.

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

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Tonelli Shalome M

2011-11-01

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

Cosmic ray air showers in the knee energy region

Indian Academy of Sciences (India)

The cosmic ray extensive air showers in the knee energy region have been studied by the North Bengal University array. The differential size spectra at different atmospheric depths show a systematic shift of the knee towards smaller shower size with the increase in atmospheric depth. The measured values of spectral ...

Satisfactory knee function after single-stage posterolateral corner reconstruction in the multi-ligament injured/dislocated knee using the anatomic single-graft technique.

Science.gov (United States)

Sanders, Thomas L; Johnson, Nick R; Pareek, Ayoosh; Krych, Aaron J; Marx, Robert G; Stuart, Michael J; Levy, Bruce A

2018-04-01

Increasing importance has been placed on the posterolateral corner (PLC) in maintaining varus and rotational stability of the knee. The goal of this study was to evaluate knee function and clinical stability following a single-graft PLC reconstruction technique and identify factors associated with poor knee function. This study identified patients with a multi-ligament knee injury between 2006 and 2013. Patients who received a single-graft fibular collateral ligament and PLC reconstruction with a single-stage surgery during the study period and had a minimum follow-up of 2 years after surgery were included. Functional outcomes were assessed using Lysholm and IKDC scores. Varus and rotational knee laxity and range of motion were assessed using physical examination. The final study cohort included 61 patients who underwent PLC reconstruction using a single-graft technique. The mean IKDC score was 74.1 (± 22.3) and the mean Lysholm score was 80.3 (± 21.8) at mean follow-up of 3.8 years (range 2-9 years). Mean range of motion at final follow-up measured from 0° to 126° [range flexion: 95-145, range extension: 0-5]. Fifty-eight patients (95%) had grade 0 varus laxity in full knee extension, and 54 patients (88.5%) had grade 0 varus laxity at 30° of knee flexion. Female gender was associated with a lower postoperative IKDC score (p = 0.04). Surgical treatment of the PLC using a single-graft technique can result in satisfactory knee function and stable physical examination findings at minimum 2 years after surgery. Female gender was predictive of poor knee function after PLC reconstruction. Surgical treatment of PLC injuries should be individualized based on the timing of surgery, specific injured knee structures, and physical examination findings. This study helps validate the use of a single-graft technique for PLC reconstruction and can be used to help counsel patients about expected knee function after surgical treatment of PLC injuries. Level of evidence

Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?

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Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C

2017-09-07

Accurate measurements of knee and hip motion are required for management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion at the hip and knee. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, hip flexion/abduction/internal rotation/external rotation and knee flexion/extension were measured using visual estimation, goniometry, and photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard, while precision was defined by the proportion of measurements within either 5° or 10°. Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although two statistically significant differences were found in measurement accuracy between the three techniques, neither of these differences met clinical significance (difference of 1.4° for hip abduction and 1.7° for the knee extension). Precision of measurements was significantly higher for digital photography than: (i) visual estimation for hip abduction and knee extension, and (ii) goniometry for knee extension only. There was no clinically significant difference in measurement accuracy between the three techniques for hip and knee motion. Digital photography only showed higher precision for two joint motions (hip abduction and knee extension). Overall digital photography shows equivalent accuracy and near-equivalent precision to visual estimation and goniometry.

The Knee injury and Osteoarthritis Outcome Score (KOOS)

DEFF Research Database (Denmark)

Roos, Ewa M.; Lohmander, L Stefan

2003-01-01

The Knee injury and Osteoarthritis Outcome Score (KOOS) was developed as an extension of the WOMAC Osteoarthritis Index with the purpose of evaluating short-term and long-term symptoms and function in subjects with knee injury and osteoarthritis. The KOOS holds five separately scored subscales...... be used for short-term and long-term follow-up of several types of knee injury including osteoarthritis. The measure is relatively new and further use of the instrument will add knowledge and suggest areas that need to be further explored and improved....

Test-Retest Reliability of Rating of Perceived Exertion and Agreement With 1-Repetition Maximum in Adults.

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Bove, Allyn M; Lynch, Andrew D; DePaul, Samantha M; Terhorst, Lauren; Irrgang, James J; Fitzgerald, G Kelley

2016-09-01

Study Design Clinical measurement. Background It has been suggested that rating of perceived exertion (RPE) may be a useful alternative to 1-repetition maximum (1RM) to determine proper resistance exercise dosage. However, the test-retest reliability of RPE for resistance exercise has not been determined. Additionally, prior research regarding the relationship between 1RM and RPE is conflicting. Objectives The purpose of this study was to (1) determine test-retest reliability of RPE related to resistance exercise and (2) assess agreement between percentages of 1RM and RPE during quadriceps resistance exercise. Methods A sample of participants with and without knee pathology completed a series of knee extension exercises and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale, then repeated the procedure 1 to 2 weeks later for test-retest reliability. To determine agreement between RPE and 1RM, participants completed knee extension exercises at various percentages of their 1RM (10% to 130% of predicted 1RM) and rated the perceived difficulty of each exercise on a 0-to-10 RPE scale. Percent agreement was calculated between the 1RM and RPE at each resistance interval. Results The intraclass correlation coefficient indicated excellent test-retest reliability of RPE for quadriceps resistance exercises (intraclass correlation coefficient = 0.895; 95% confidence interval: 0.866, 0.918). Overall percent agreement between RPE and 1RM was 60%, but agreement was poor within the ranges that would typically be used for training (50% 1RM for muscle endurance, 70% 1RM and greater for strength). Conclusion Test-retest reliability of perceived exertion during quadriceps resistance exercise was excellent. However, agreement between the RPE and 1RM was poor, especially in common training zones for knee extensor strengthening. J Orthop Sports Phys Ther 2016;46(9):768-774. Epub 5 Aug 2016. doi:10.2519/jospt.2016.6498.

Lean muscle volume of the thigh has a stronger relationship with muscle power than muscle strength in women with knee osteoarthritis.

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Davison, Michael J; Maly, Monica R; Keir, Peter J; Hapuhennedige, Sandani M; Kron, Amie T; Adachi, Jonathan D; Beattie, Karen A

2017-01-01

Thigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA. Women (n=20) 55years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests. Quadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B=0.624; p=0.017) and flexor (B=1.518; p=0.032) power, but not knee extensor (B=0.001; p=0.615) or flexor (B=0.001; p=0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance. Muscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Neurodynamic responses to the femoral slump test in patients with anterior knee pain syndrome.

Science.gov (United States)

Lin, Pei-Ling; Shih, Yi-Fen; Chen, Wen-Yin; Ma, Hsiao-Li

2014-05-01

Matched-control, cross-sectional study. The purpose of this study was to compare the responses to the femoral slump test (FST), including the change in hip range of motion and level of discomfort, between subjects with and without anterior knee pain. Anterior knee pain syndrome is a common problem among adults. The FST is the neurodynamic test used to assess the mechanosensitivity of the femoral component of the nervous system. However, as of yet, there is no literature discussing the use of the FST in patients with anterior knee pain. Thirty patients with anterior knee pain and 30 control participants, matched by gender, age, and dominant leg, were recruited. The subjects received the FST, during which the hip extension angle and the location and intensity of pain/discomfort were recorded. Reproduction of symptoms that were alleviated by neck extension was interpreted as a positive test. Differences in hip extension angle and pain intensity between groups were examined using a 2-way, repeated-measures analysis of variance and a Kruskal-Wallis analysis. The level of significance was set at α = .05. Subjects with anterior knee pain had a smaller hip extension angle than that of controls (-3.6° ± 5.3° versus 0.6° ± 6.1°; mean difference, 4.2°; 95% confidence interval [CI]: 1.24°, 7.15°; P = .006). Eight patients with anterior knee pain showed a positive FST, and those with a positive FST had a smaller hip extension angle (-5.7° ± 4.5°) than that of controls (mean difference, 6.3°; 95% CI: 0.8°, 11.8°; P = .007). There was no difference in the hip extension angle between the positive and negative FST groups (mean difference, 2.9°; 95% CI: -8.5°, 2.0°) or between the negative FST and control groups (mean difference, 3.4°; 95% CI: -0.4°, 7.3°). Results of this study suggest that altered mechanosensitivity of the femoral nerve occurred in the patients with anterior knee pain who presented with a positive FST. The role of increased mechanosensitivity

Collateral ligament strains during knee joint laxity evaluation before and after TKA.

Science.gov (United States)

Delport, Hendrik; Labey, Luc; De Corte, Ronny; Innocenti, Bernardo; Vander Sloten, Jos; Bellemans, Johan

2013-08-01

Passive knee stability is provided by the soft tissue envelope. There is consensus among orthopedic surgeons that good outcome in Total Knee Arthroplasty requires equal tension in the medial/lateral compartment of the knee joint, as well as equal tension in the flexion/extension gap. The purpose of this study was to quantify the ligament laxity in the normal non-arthritic knee before and after Posterior-Stabilized Total Knee Arthroplasty. We hypothesized that the Medial/Lateral Collateral Ligament shows minimal changes in length when measured directly by extensometers in the native human knee during varus/valgus laxity testing. We also hypothesized that due to differences in material properties and surface geometry, native laxity is difficult to reconstruct using a Posterior-Stabilized Total Knee. Six specimens were used to perform this in vitro cadaver test using extensometers to provide numerical values for laxity and varus-valgus tilting in the frontal plane. This study enabled a precise measurement of varus-valgus laxity as compared with the clinical assessment. The strains in both ligaments in the replaced knee were different from those in the native knee. Both ligaments were stretched in extension, in flexion the Medial Collateral Ligament tends to relax and the Lateral Collateral Ligament remains tight. As material properties and surface geometry of the replaced knee add stiffness to the joint, we recommend to avoid overstuffing the joint, when using this type of Posterior-Stabilized Total Knee Arthroplasty, in order to obtain varus/valgus laxity close to the native joint. Copyright © 2013 Elsevier Ltd. All rights reserved.

Epidemiology of jumper's knee.

Science.gov (United States)

Ferretti, A

1986-01-01

Jumper's knee is a typical functional overload injury because it affects those athletes who submit their knee extensor mechanisms to intense and repeated stress, e.g. volleyball and basketball players, high and long jumpers. According to the classification of Perugia and colleagues, it is an insertional tendinopathy affecting, in order of frequency, the insertion of the patellar tendon into the patella (65% of cases), attachment of the quadriceps tendon to the patella (25%) and the attachment of the patellar tendon to the tibial tuberosity (10%). The frequent occurrence of this injury in athletes led to the study of factors that may contribute to its onset and aggravation. These factors are divided into extrinsic (i.e. kind of sport practised and training methods used) and intrinsic (i.e. connected with the somatic and morphological characteristics of the athletes). On the basis of our experience and after a review of the literature it appears, contrary to what has been repeatedly claimed in the past, the extrinsic factors are more important than the intrinsic in the aetiology of jumper's knee. The effect of traumatic incidents and use of elastic kneecap guards should also be considered negligible. The intrinsic causes of jumper's knee, can be sought in the mechanical properties of tendons (resistance, elasticity and extensibility) rather than in morphological or biomechanical abnormalities of the knee extensor mechanism.

Civamide cream 0.075% in patients with osteoarthritis of the knee: a 12-week randomized controlled clinical trial with a longterm extension.

Science.gov (United States)

Schnitzer, Thomas J; Pelletier, Jean-Pierre; Haselwood, Doug M; Ellison, William T; Ervin, John E; Gordon, Richard D; Lisse, Jeffrey R; Archambault, W Tad; Sampson, Allan R; Fezatte, Heidi B; Phillips, Scott B; Bernstein, Joel E

2012-03-01

To evaluate the safety and efficacy of civamide cream 0.075% for the treatment of osteoarthritis (OA) of the knee. We conducted a 12-week, multicenter, randomized, double-blind study with a 52-week open-label extension. Patients with OA of the knee received either civamide cream 0.075% or a lower dose of civamide cream, 0.01%, as the control. The 3 co-primary endpoints in the double-blind study were the time-weighted average (TWA) of change from baseline to Day 84 in the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain subscale, the WOMAC physical function subscale, and the Subject Global Evaluation (SGE). In the 52-week open-label extension study, the Osteoarthritis Pain Score and SGE were assessed. A total of 695 patients were randomized to receive civamide cream 0.075% (n = 351) or civamide cream 0.01% (control; n = 344) in the double-blind study. Significance in favor of civamide cream 0.075% was achieved for the TWA for all 3 co-primary efficacy variables: WOMAC pain (p = 0.009), WOMAC physical function (p < 0.001), and SGE (p = 0.008); and at Day 84 for these 3 variables (p = 0.013, p < 0.001, and p = 0.049, respectively). These analyses accounted for significant baseline-by-treatment interactions. In the 52-week open-label extension, efficacy was maintained. Civamide cream 0.075% was well tolerated throughout the studies. These studies demonstrate the efficacy of civamide cream for up to 1 year of continuous use. Civamide cream, with its lack of systemic absorption, does not have the potential for serious systemic toxicity, in contrast to several other OA treatments.

Intraoperative joint gaps and mediolateral balance affect postoperative knee kinematics in posterior-stabilized total knee arthroplasty.

Science.gov (United States)

Watanabe, Toshifumi; Muneta, Takeshi; Sekiya, Ichiro; Banks, Scott A

2015-12-01

Adjusting joint gaps and establishing mediolateral (ML) soft tissue balance are considered essential interventions for better outcomes in total knee arthroplasty (TKA). However, the relationship between intraoperative laxity measurements and weightbearing knee kinematics has not been well explored. This study aimed to quantify the effect of intraoperative joint gaps and ML soft tissue balance on postoperative knee kinematics in posterior-stabilized (PS)-TKA. We investigated 44 knees in 34 patients who underwent primary PS-TKA by a single surgeon. The central joint gaps and ML tilting angles at 0°, 10°, 30°, 60°, 90°, 120° and 135° flexion were measured during surgery. At a minimum of two year follow-up, we analyzed in vivo kinematics of these knees and examined the influence of intraoperative measurements on postoperative kinematics. Gap difference of knee flexion at 135° minus 0° was correlated with the total posterior translation of lateral femoral condyle (r=0.336, p=0.042) and femoral external rotation (r=0.488, p=0.002) during squatting, anteroposterior position of lateral femoral condyle (r=-0.510, p=0.001) and maximum knee flexion (r=0.355, p=0.031) in kneeling. Similar correlations were observed between deep flexion gap differences with respect to the 90° reference and postoperative knee kinematics. Well-balanced knees showed less anterior translation of medial femoral condyle in mid- to deep flexion, consistent femoral external rotation, and the most neutral valgus/varus rotation compared with unbalanced knees. These findings indicate the importance of adequate intraoperative joint gaps in deep flexion and ML soft tissue balance throughout the range of motion. Copyright © 2015 Elsevier B.V. All rights reserved.

No difference in gait between posterior cruciate retention and the posterior stabilized design after total knee arthroplasty

NARCIS (Netherlands)

van den Boom, Lennard G. H.; Halbertsma, Jan P. K.; van Raaij, Jos J. A. M.; Brouwer, Reinoud W.; Bulstra, Sjoerd K.; van den Akker-Scheek, Inge

2014-01-01

In the present study, knee joint kinematics (e.g. knee flexion/extension) and kinetics (e.g. knee flexion moments) are assessed after total knee arthroplasty (TKA) between patients implanted with either a unilateral posterior stabilized (PS) and a posterior cruciate-retaining (PCR) design. It was

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

Science.gov (United States)

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

2016-01-01

Total knee replacement (TKR) is commonly used to correct end-stage knee osteoarthritis. Unfortunately, difficulty with stair climbing often persists and prolongs the challenges of TKR patents. Complete understanding of loading at the knee is of great interest in order to aid patient populations, implant manufacturers, rehabilitation, and future healthcare research. Musculoskeletal modeling and simulation approximates joint loading and corresponding muscle forces during a movement. The purpose of this study was to determine if knee joint loadings following TKR are recovered to the level of healthy individuals, and determine the differences in muscle forces causing those loadings. Data from five healthy and five TKR patients were selected for musculoskeletal simulation. Variables of interest included knee joint reaction forces (JRF) and the corresponding muscle forces. A paired samples t-test was used to detect differences between groups for each variable of interest (pknee extension moment and muscle forces during the loading response phase indicates the presence of deficits in TKR in quadriceps muscle force production during stair ascent. This result combined with greater flexor muscle forces resulted in similar compressive JRF during loading response between groups. PMID:27258086

Soft-tissue tension total knee arthroplasty.

Science.gov (United States)

Asano, Hiroshi; Hoshino, Akiho; Wilton, Tim J

2004-08-01

It is far from clear how best to define the proper strength of soft-tissue tensioning in total knee arthroplasty (TKA). We attached a torque driver to the Monogram balancer/tensor device and measured soft-tissue tension in full extension and 90 degrees flexion during TKA. In our surgical procedure, when we felt proper soft-tissue tension was being applied, the mean distraction force was noted to be 126N in extension and 121N in flexion. There was no significant correlation between soft-tissue tension and the postoperative flexion angle finally achieved. To the best of our knowledge, this is the first study to assess the actual distraction forces in relation to soft-tissue tension in TKA. Further study may reveal the most appropriate forces to achieve proper soft-tissue tension in the wide variety of circumstances presenting at knee arthroplasty.

Effect of telescopic distal extension removable partial dentures on oral health related quality of life and maximum bite force: A preliminary cross over study.

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Elsyad, Moustafa Abdou; Mostafa, Aisha Zakaria

2018-01-01

This cross over study aimed to evaluate the effect of telescopic distal extension removable partial dentures on oral health related quality of life and maximum bite force MATERIALS AND METHODS: Twenty patients with complete maxillary edentulism and partially edentulous mandibles with anterior teeth only remaining were selected for this cross over study. All patients received complete maxillary dentures and mandibular partial removable dental prosthesis (PRDP, control). After 3 months of adaptation, PRDP was replaced with conventional telescopic partial dentures (TPD) or telescopic partial dentures with cantilevered extensions (TCPD) in a quasi-random method. Oral health related quality of life (OHRQoL) was measured using OHIP-14 questionnaire and Maximum bite force (MBF) was measured using a bite force transducer. Measurements were performed 3 months after using each of the following prostheses; PRDP, TPD, and TCPD. TCPD showed the OHIP-14 lowest scores (i.e., the highest patient satisfaction with their OHRQoL), followed by TPD, and PRDP showed the highest OHIP-14 scores (i.e., the lowest patient satisfaction with OHRQoL). TCPD showed the highest MBF (70.7 ± 3.71), followed by TPD (57.4 ± 3.43) and the lowest MBF (40.2 ± 2.20) was noted with PRDP. WITHIN The Limitations of This Study, Mandibular Telescopic Distal Extension Removable Partial Dentures with Cantilevered Extensions Were Associated with Improved Oral Health Related Quality of Life and Maximum Bite Force Compared to Telescopic or Conventional PRDP. Telescopic distal extension removable prostheses is an esthetic restoration in partially edentulous patients with free end saddle. This article describes the addition of cantilevered extensions of this prosthesis. The results showed that telescopic distal extension removable prostheses with cantilevered extensions were associated with improved oral health related quality of life and maximum bite force compared to telescopic or conventional RPDs

Clinical significance of subchondral cortical signal intensities in osteoarthritis of knee joints

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Eijiro; Torisu, Takehiko; Nakamura, Taro; Masumi, Shogo [Oita Medical Univ., Hazama (Japan); Tomari, Kazuhide; Asao, Tunenori; Takagi, Kazuhiro

1996-09-01

The purpose of this study was to evaluate the abnormal intensity in medial femoral condyle on MR imaging in patients with osteoarthritis of the knee. Eighty knees of fifty-eight patients with osteoarthritis of the knee were underwent plain radiography and MR imaging. According to the extension of the abnormal low intensity on T{sub 1} weighted images in medial femoral chondyle, all cases were classified into four types (no exist: 30.0%, small: 30.0%, middle: 30.0%, large: 10.0%). The extension of the abnormal low intensity was closely related to radiographic stage and femoral tibial angle. After radiological examination, in thirteen knees, the biopsy of the abnormal low intensity area on T{sub 1} weighted MR imaging was performed at the time of total knee arthroplasty. Pathological examination revealed that the causative factor of abnormal low intensity on T{sub 1} weighted MR imaging in the medial femoral condyle was trabecular hypertrophy. Our results suggest that the abnormal low intensity on T{sub 1} weighted MR imaging reflects the loading force. (author)

Clinical significance of subchondral cortical signal intensities in osteoarthritis of knee joints

International Nuclear Information System (INIS)

Nakamura, Eijiro; Torisu, Takehiko; Nakamura, Taro; Masumi, Shogo; Tomari, Kazuhide; Asao, Tunenori; Takagi, Kazuhiro.

1996-01-01

The purpose of this study was to evaluate the abnormal intensity in medial femoral condyle on MR imaging in patients with osteoarthritis of the knee. Eighty knees of fifty-eight patients with osteoarthritis of the knee were underwent plain radiography and MR imaging. According to the extension of the abnormal low intensity on T 1 weighted images in medial femoral chondyle, all cases were classified into four types (no exist: 30.0%, small: 30.0%, middle: 30.0%, large: 10.0%). The extension of the abnormal low intensity was closely related to radiographic stage and femoral tibial angle. After radiological examination, in thirteen knees, the biopsy of the abnormal low intensity area on T 1 weighted MR imaging was performed at the time of total knee arthroplasty. Pathological examination revealed that the causative factor of abnormal low intensity on T 1 weighted MR imaging in the medial femoral condyle was trabecular hypertrophy. Our results suggest that the abnormal low intensity on T 1 weighted MR imaging reflects the loading force. (author)

Patterns in the knee flexion-extension moment profile during stair ascent and descent in patients with total knee arthroplasty.

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McClelland, Jodie A; Feller, Julian A; Menz, Hylton B; Webster, Kate E

2014-06-03

The aim of this study was to investigate the prevalence of abnormal knee biomechanical patterns in 40 patients with a modern TKA prosthesis, compared to 40 matched control participants when ascending and descending stairs. Fewer patients were able to ascend (65%) or descend stairs (53%) unassisted than controls (83%). Of the participants who could ascend and descend, cluster analysis classified most patients (up to 77%) as demonstrating a similar knee moment pattern as all controls. A small subgroup of patients who completed the tasks did so with distinctly abnormal biomechanics compared to other patients and controls. These findings suggest that recovery of normal stair climbing is possible. However, rehabilitation might be more effective if it were tailored to account for these differences between patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Robert Rasnick

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

Influence of increasing knee flexion angle on knee-ankle varus stress during single-leg jump landing

Directory of Open Access Journals (Sweden)

Mariam A. Ameer, PhD

2017-12-01

Full Text Available Objectives: The primary aim of this study was to identify the relationship between the peak knee flexion angle and knee-ankle varus stress in the landing phase of the single-leg jump during running. Methods: Fifteen male handball players from the first Saudi Arabian handball team were incorporated in this study. Each player performed a single-leg jump-land after running a fixed distance of 450 cm. The data were measured using a 3D motion analysis system. The maximum knee flexion angle, knee varus angle, centre of pressure pathway in the medio-lateral direction, and ankle varus moment were measured. Results: The Pearson Product Moment Correlation showed that a greater knee flexion angle was related to a greater lateral displacement of the centre of pressure (r = 0.794, P = 0.000, a greater ankle varus moment (r = 0.707, P = 0.003, and a greater knee varus angle (r = 0.753, P = 0.001. In addition, the greater ankle varus moment was related to the greater lateral displacement of the centre of pressure (r = 0.734, P = 0.002. Conclusions: These findings may help physical therapists and conditioning professionals to understand the impact of increasing knee flexion angle on the lower limb joints. Such findings may help to develop training protocols for enhancing the lateral body reaction during the landing phase of the single-leg jump, which may protect the knee and ankle joints from excessive varus stresses. Keywords: 3D motion analysis, Ankle kinetic, Centre of pressure pathway, Handball playing, Knee kinematic, Single-leg jump

Estimating the Mechanical Behavior of the Knee Joint during Crouch Gait: Implications for Real-Time Motor Control of Robotic Knee Orthoses

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Damiano, Diane L.; Bulea, Thomas C.

2016-01-01

Individuals with cerebral palsy frequently exhibit crouch gait, a pathological walking pattern characterized by excessive knee flexion. Knowledge of the knee joint moment during crouch gait is necessary for the design and control of assistive devices used for treatment. Our goal was to 1) develop statistical models to estimate knee joint moment extrema and dynamic stiffness during crouch gait, and 2) use the models to estimate the instantaneous joint moment during weight-acceptance. We retrospectively computed knee moments from 10 children with crouch gait and used stepwise linear regression to develop statistical models describing the knee moment features. The models explained at least 90% of the response value variability: peak moment in early (99%) and late (90%) stance, and dynamic stiffness of weight-acceptance flexion (94%) and extension (98%). We estimated knee extensor moment profiles from the predicted dynamic stiffness and instantaneous knee angle. This approach captured the timing and shape of the computed moment (root-mean-squared error: 2.64 Nm); including the predicted early-stance peak moment as a correction factor improved model performance (root-mean-squared error: 1.37 Nm). Our strategy provides a practical, accurate method to estimate the knee moment during crouch gait, and could be used for real-time, adaptive control of robotic orthoses. PMID:27101612

Effectiveness of an Articulated Knee Hyperextension Orthosis in Genu Recurvatum

Directory of Open Access Journals (Sweden)

Rahul ASRM

2014-08-01

Full Text Available Genu Recurvatum is a deformity of knee joint that tends to push it backwards by excessive extension in tibio-femoral joints. This poses a significant challenge because of technical difficulties and a high incidence of recurrence. This report describes a 63 years old male diagnosed as post-polio residual paralysis who showed excessive genu recurvatum of his left knee during long standing and walking. An Articulated Knee Hyperextension Orthosis (KAFO was tried to check its effectiveness in terms of gait and energy expenditure.

Wide step width reduces knee abduction moment of obese adults during stair negotiation.

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Yocum, Derek; Weinhandl, Joshua T; Fairbrother, Jeffrey T; Zhang, Songning

2018-05-15

An increased likelihood of developing obesity-related knee osteoarthritis may be associated with increased peak internal knee abduction moments (KAbM). Increases in step width (SW) may act to reduce this moment. The purpose of this study was to determine the effects of increased SW on knee biomechanics during stair negotiation of healthy-weight and obese participants. Participants (24: 10 obese and 14 healthy-weight) used stairs and walked over level ground while walking at their preferred speed in two different SW conditions - preferred and wide (200% preferred). A 2 × 2 (group × condition) mixed model analysis of variance was performed to analyze differences between groups and conditions (p < 0.05). Increased SW increased the loading-response peak knee extension moment during descent and level gait, decreased loading-response KAbMs, knee extension and abduction range of motion (ROM) during ascent, and knee adduction ROM during descent. Increased SW increased loading-response peak mediolateral ground reaction force (GRF), increased peak knee abduction angle during ascent, and decreased peak knee adduction angle during descent and level gait. Obese participants experienced disproportionate changes in loading-response mediolateral GRF, KAbM and peak adduction angle during level walking, and peak knee abduction angle and ROM during ascent. Increased SW successfully decreased loading-response peak KAbM. Implications of this finding are that increased SW may decrease medial compartment knee joint loading, decreasing pain and reducing joint deterioration. Increased SW influenced obese and healthy-weight participants differently and should be investigated further. Copyright © 2018. Published by Elsevier Ltd.

Reliability and validity of the Performance Recorder 1 for measuring isometric knee flexor and extensor strength.

Science.gov (United States)

Neil, Sarah E; Myring, Alec; Peeters, Mon Jef; Pirie, Ian; Jacobs, Rachel; Hunt, Michael A; Garland, S Jayne; Campbell, Kristin L

2013-11-01

Muscular strength is a key parameter of rehabilitation programs and a strong predictor of functional capacity. Traditional methods to measure strength, such as manual muscle testing (MMT) and hand-held dynamometry (HHD), are limited by the strength and experience of the tester. The Performance Recorder 1 (PR1) is a strength assessment tool attached to resistance training equipment and may be a time- and cost-effective tool to measure strength in clinical practice that overcomes some limitations of MMT and HHD. However, reliability and validity of the PR1 have not been reported. Test-retest and inter-rater reliability was assessed using the PR1 in healthy adults (n  =  15) during isometric knee flexion and extension. Criterion-related validity was assessed through comparison of values obtained from the PR1 and Biodex® isokinetic dynamometer. Test-retest reliability was excellent for peak knee flexion (intra-class correlation coefficient [ICC] of 0.96, 95% CI: 0.85, 0.99) and knee extension (ICC  =  0.96, 95% CI: 0.87, 0.99). Inter-rater reliability was also excellent for peak knee flexion (ICC  =  0.95, 95% CI: 0.85, 0.99) and peak knee extension (ICC  =  0.97, 95% CI: 0.91, 0.99). Validity was moderate for peak knee flexion (ICC  =  0.75, 95% CI: 0.38, 0.92) but poor for peak knee extension (ICC  =  0.37, 95% CI: 0, 0.73). The PR1 provides a reliable measure of isometric knee flexor and extensor strength in healthy adults that could be used in the clinical setting, but absolute values may not be comparable to strength assessment by gold-standard measures.

Do changes in neuromuscular activation contribute to the knee extensor angle-torque relationship?

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Lanza, Marcel B; Balshaw, Thomas G; Folland, Jonathan P

2017-08-01

What is the central question of the study? Do changes in neuromuscular activation contribute to the knee extensor angle-torque relationship? What is the main finding and its importance? Both agonist (quadriceps) and antagonist coactivation (hamstrings) differed with knee joint angle during maximal isometric knee extensions and thus both are likely to contribute to the angle-torque relationship. Specifically, two independent measurement techniques showed quadriceps activation to be lower at more extended positions. These effects might influence the capacity for neural changes in response to training and rehabilitation at different knee joint angles. The influence of joint angle on knee extensor neuromuscular activation is unclear, owing in part to the diversity of surface electromyography (sEMG) and/or interpolated twitch technique (ITT) methods used. The aim of the study was to compare neuromuscular activation, using rigorous contemporary sEMG and ITT procedures, during isometric maximal voluntary contractions (iMVCs) of the quadriceps femoris at different knee joint angles and examine whether activation contributes to the angle-torque relationship. Sixteen healthy active men completed two familiarization sessions and two experimental sessions of isometric knee extension and knee flexion contractions. The experimental sessions included the following at each of four joint angles (25, 50, 80 and 106 deg): iMVCs (with and without superimposed evoked doublets); submaximal contractions with superimposed doublets; and evoked twitch and doublet contractions whilst voluntarily passive, and knee flexion iMVC at the same knee joint positions. The absolute quadriceps femoris EMG was normalized to the peak-to-peak amplitude of an evoked maximal M-wave, and the doublet-voluntary torque relationship was used to calculate activation with the ITT. Agonist activation, assessed with both normalized EMG and the ITT, was reduced at the more extended compared with the more flexed

Effects of changes in skiing posture on the kinetics of the knee joint.

Science.gov (United States)

Koyanagi, Maki; Shino, Konsei; Yoshimoto, Yoji; Inoue, Satoru; Sato, Mutsumi; Nakata, Ken

2006-01-01

This study was performed to investigate the effects of changes in the skiing posture on mechanical stress across the knee joint. The aim of the present study was to establish a safer form of skiing for the prevention of injury to the anterior cruciate ligament of the knee (ACL). Ten healthy volunteers were placed on a force plate on an artificial slope, and assumed forward and backward bending postures with a single leg by changing their centre of gravity. The knee flexion angles were limited to approximately 30 degrees by orthotics in each posture. Joint moments of the lower extremity were analyzed using a motion analysis system, and the muscle activities of the lower extremity were recorded by EMG and digitised to integrated EMG in each posture. In addition, extrusion of the lower leg by the boot was measured using a force sensor sheet inserted behind the calf. We found that the extension moment of the hip and ankle joints, and muscular activity of the hamstrings were increased in forward bending, whereas the extension moment of the knee and muscular activity of the quadriceps were decreased. Conversely, the muscular activity of the quadriceps, the flexion moment of the hip, extension moment of the knee joint, and pressure of the boot were increased in backward bending, whereas muscular activity of the hamstrings was decreased. The dependency on the hamstrings increased in forward bending in a skiing posture on a slope with slight knee flexion. Therefore, forward bending seemed to be an advantageous posture for the prevention of ACL injury. Conversely, in a backward bending skiing posture, the extension moment of the knee joint produced by muscle contraction of the quadriceps also increased imbalance in the hamstrings. The results of this study suggest that the internal force exerted by the quadriceps, in addition to the passive factor of extrusion of the lower leg by the boot, may contribute to non-contact ACL injury in a backward bending posture while skiing.

Variability of Measurement of Patellofemoral Indices with Knee Flexion and Quadriceps Contraction: An MRI-Based Anatomical Study

Science.gov (United States)

Laugharne, Edward; Bali, Navi; Purushothamdas, Sanjay; Almallah, Faris; Kundra, Rik

2016-01-01

Purpose The purpose of this study was to investigate the impact of varying knee flexion and quadriceps activity on patellofemoral indices measured on magnetic resonance imaging (MRI). Materials and Methods MRI of the knee was performed in 20 patients for indications other than patellar or patellofemoral pathology. Axial and sagittal sequences were performed in full extension of the knee with the quadriceps relaxed, full extension of the knee with the quadriceps contracted, 30° flexion of the knee with the quadriceps relaxed, and 30° flexion with the quadriceps contracted. Bisect offset, patella tilt angle, Insall-Salvati ratio and Caton-Deschamps index were measured. Results With the knee flexed to 30° and quadriceps relaxed, the mean values of patellar tilt angle, bisect offset, Insall-Salvati ratio and Caton-Deschamps index were all within normal limits. With the knee extended and quadriceps contracted, the mean patellar tilt angle (normal value, patellofemoral indices. MRI taken with the knee in 30° of flexion allows more reliable assessment of the patellofemoral joint and minimises the confounding effect of quadriceps contraction. PMID:27894177

[Research progress of three-dimensional digital model for repair and reconstruction of knee joint].

Science.gov (United States)

Tong, Lu; Li, Yanlin; Hu, Meng

2013-01-01

To review recent advance in the application and research of three-dimensional digital knee model. The recent original articles about three-dimensional digital knee model were extensively reviewed and analyzed. The digital three-dimensional knee model can simulate the knee complex anatomical structure very well. Based on this, there are some developments of new software and techniques, and good clinical results are achieved. With the development of computer techniques and software, the knee repair and reconstruction procedure has been improved, the operation will be more simple and its accuracy will be further improved.

The effect of posterior tibial slope on knee flexion in posterior-stabilized total knee arthroplasty.

Science.gov (United States)

Shi, Xiaojun; Shen, Bin; Kang, Pengde; Yang, Jing; Zhou, Zongke; Pei, Fuxing

2013-12-01

To evaluate and quantify the effect of the tibial slope on the postoperative maximal knee flexion and stability in the posterior-stabilized total knee arthroplasty (TKA). Fifty-six patients (65 knees) who had undergone TKA with the posterior-stabilized prostheses were divided into the following 3 groups according to the measured tibial slopes: Group 1: ≤4°, Group 2: 4°-7° and Group 3: >7°. The preoperative range of the motion, the change in the posterior condylar offset, the elevation of the joint line, the postoperative tibiofemoral angle and the preoperative and postoperative Hospital for Special Surgery (HSS) scores were recorded. The tibial anteroposterior translation was measured using the Kneelax 3 Arthrometer at both the 30° and the 90° flexion angles. The mean values of the postoperative maximal knee flexion were 101° (SD 5), 106° (SD 5) and 113° (SD 9) in Groups 1, 2 and 3, respectively. A significant difference was found in the postoperative maximal flexion between the 3 groups (P slope resulted in a 1.8° flexion increment (r = 1.8, R (2) = 0.463, P slope can significantly increase the postoperative maximal knee flexion. The tibial slope with an appropriate flexion and extension gap balance during the operation does not affect the joint stability.

Above and below knee femoropopliteal VIABAHN®.

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Shackles, Christopher; Rundback, John H; Herman, Kevin; David, Yitzchak; Barkarma, Ravit

2015-04-01

To assess the clinical outcomes of VIABAHN® stent grafts deployed across the knee to those deployed above the knee. The placement of stent-grafts across the knee joint and extending into the distal popliteal artery has been avoided due to a perceived higher risk of stent fractures, restenosis, and thrombosis due to the unique hemodynamic forces in this region. A retrospective evaluation was conducted of 114 patients in 127 limbs. Patients were divided into two groups based on the location of the distal end of the deployed VIABAHN® stent: above knee (AK) (n=89) in which the VIABAHN® implant ended at or above the femoral condyles and below the knee (BK) (n=38) with extension of the graft into the below knee popliteal segment. Study end points were loss of primary, assisted, and secondary patency. One year primary, assisted, and secondary patency rates in the AK versus BK group were 67.7% vs. 47.2% (P=0.0092), 77.1% vs. 53.7% (P=0.0022), and 86.3% vs. 59.8% (P=0.0035), respectively. Univariate analysis demonstrated an increased relative risk of a primary [RR=2.07 (P=0.001)], assisted [RR=2.34 (P=0.002)], or secondary events [RR=2.98 (P=0.002)] in patients when the stent was placed below the femoral condyles. Major amputations occurred in 10% of AK and 34% of BK patients (P=0.002). VIABAHN® stent grafts have a significantly lower clinical patency and higher rates of amputation when they extend across the knee joint. © 2014 Wiley Periodicals, Inc.

[Custom-designed 3D tibial augmentation for knee replacement].

Science.gov (United States)

Jirman, R; Vavrík, P; Horák, Z

2009-02-01

Reconstruction with the use of custom-made implants aims at optimal replacement of lost or damaged bone structures and restoration of their funkction. In this study the development and construction of a custom-made implant and the operative technique used for the treatment of an extensive tibial defect are described. The patient was a 65-year-old man treated for over 20 years for psoriatic arthritis and severe instability of the right knee, particularly in the frontal plane, with a worsening varus deformity. The radiogram showed an extensive destruction of the medial tibial condyle that also deeply involved the lateral condyle. The extent of defect made it impossible to use any commercial tibial augmentation. The geometry of the custom-designed implant for the medial tibial condyle was constructed on the basis of a 3D defect model and the shape of the medial tibial condyle of the collateral knee seen on CT scans. After its correct shape was verified on a plastic model, its coordinates were set in the software of a machine tool, and a titanium augmentation otherwise compatible with a standard knee replacement was produced.The use of such a custom implant to complete standard total knee arthroplasty has so far been demanding in terms of organisation and manufacture. Its production in the future could be facilitated by substituting titanium for plastic material such as poly-ether-ether-ketone (PEEK). Key words: custom-made implant, tibial augmentation, knee prosthesis.

Measurement of the local muscular metabolism by time-domain near infrared spectroscopy during knee flex-extension induced by functional electrical stimulation

Science.gov (United States)

Contini, D.; Spinelli, L.; Torricelli, A.; Ferrante, S.; Pedrocchi, A.; Molteni, F.; Ferrigno, G.; Cubeddu, R.

2009-02-01

We present a preliminary study that combines functional electrical stimulation and time-domain near infrared spectroscopy for a quantitative measurement of the local muscular metabolism during rehabilitation of post-acute stroke patients. Seven healthy subjects and nine post-acute stroke patients underwent a protocol of knee flex-extension of the quadriceps induced by functional electrical stimulation. During the protocol time-domain near infrared spectroscopy measurement were performed on both left and right muscle. Hemodynamic parameters (concentration of oxy- and deoxy-genated hemoglobin) during baseline did not show any significant differences between healthy subject and patients, while functional performances (knee angle amplitude) were distinctly different. Nevertheless, even if their clinical histories were noticeably different, there was no differentiation among functional performances of patients. On the basis of the hemodynamic parameters measured during the recovery phase, instead, it was possible to identify two classes of patients showing a metabolic trend similar or very different to the one obtained by healthy subjects. The presented results suggest that the combination of functional and metabolic information can give an additional tool to the clinicians in the evaluation of the rehabilitation in post-acute stroke patients.

Alterations in walking knee joint stiffness in individuals with knee osteoarthritis and self-reported knee instability.

Science.gov (United States)

Gustafson, Jonathan A; Gorman, Shannon; Fitzgerald, G Kelley; Farrokhi, Shawn

2016-01-01

Increased walking knee joint stiffness has been reported in patients with knee osteoarthritis (OA) as a compensatory strategy to improve knee joint stability. However, presence of episodic self-reported knee instability in a large subgroup of patients with knee OA may be a sign of inadequate walking knee joint stiffness. The objective of this work was to evaluate the differences in walking knee joint stiffness in patients with knee OA with and without self-reported instability and examine the relationship between walking knee joint stiffness with quadriceps strength, knee joint laxity, and varus knee malalignment. Overground biomechanical data at a self-selected gait velocity was collected for 35 individuals with knee OA without self-reported instability (stable group) and 17 individuals with knee OA and episodic self-reported instability (unstable group). Knee joint stiffness was calculated during the weight-acceptance phase of gait as the change in the external knee joint moment divided by the change in the knee flexion angle. The unstable group walked with lower knee joint stiffness (p=0.01), mainly due to smaller heel-contact knee flexion angles (pknee flexion excursions (pknee stable counterparts. No significant relationships were observed between walking knee joint stiffness and quadriceps strength, knee joint laxity or varus knee malalignment. Reduced walking knee joint stiffness appears to be associated with episodic knee instability and independent of quadriceps muscle weakness, knee joint laxity or varus malalignment. Further investigations of the temporal relationship between self-reported knee joint instability and walking knee joint stiffness are warranted. Copyright © 2015 Elsevier B.V. All rights reserved.

The association between reduced knee joint proprioception and medial meniscal abnormalities using MRI in knee osteoarthritis: results from the Amsterdam osteoarthritis cohort.

Science.gov (United States)

van der Esch, M; Knoop, J; Hunter, D J; Klein, J-P; van der Leeden, M; Knol, D L; Reiding, D; Voorneman, R E; Gerritsen, M; Roorda, L D; Lems, W F; Dekker, J

2013-05-01

Osteoarthritis (OA) of the knee is characterized by pain and activity limitations. In knee OA, proprioceptive accuracy is reduced and might be associated with pain and activity limitations. Although causes of reduced proprioceptive accuracy are divergent, medial meniscal abnormalities, which are highly prevalent in knee OA, have been suggested to play an important role. No study has focussed on the association between proprioceptive accuracy and meniscal abnormalities in knee OA. To explore the association between reduced proprioceptive accuracy and medial meniscal abnormalities in a clinical sample of knee OA subjects. Cross-sectional study in 105 subjects with knee OA. Knee proprioceptive accuracy was assessed by determining the joint motion detection threshold in the knee extension direction. The knee was imaged with a 3.0 T magnetic resonance (MR) scanner. Number of regions with medial meniscal abnormalities and the extent of abnormality in the anterior and posterior horn and body were scored according to the Boston-Leeds Osteoarthritis Knee Score (BLOKS) method. Multiple regression analyzes were used to examine whether reduced proprioceptive accuracy was associated with medial meniscal abnormalities in knee OA subjects. Mean proprioceptive accuracy was 2.9° ± 1.9°. Magnetic resonance imaging (MRI)-detected medial meniscal abnormalities were found in the anterior horn (78%), body (80%) and posterior horn (90%). Reduced proprioceptive accuracy was associated with both the number of regions with meniscal abnormalities (P knee complaints. This is the first study showing that reduced proprioceptive accuracy is associated with medial meniscal abnormalities in knee OA. The study highlights the importance of meniscal abnormalities in understanding reduced proprioceptive accuracy in persons with knee OA. Copyright © 2013 Osteoarthritis Research Society International. All rights reserved.

Agreement and Reliability of Functional Performance and Muscle Power in Patients with Advanced Osteoarthritis of the Hip or Knee

DEFF Research Database (Denmark)

Villadsen, Allan; Roos, Ewa M; Overgaard, Søren

2012-01-01

-time repeated chair stands, and repeated unilateral knee bending). RESULTS: For single-joint and multijoint maximal peak power and functional performance measures, we demonstrated poor (CVws, approximately 25%, single-joint hip extension) and moderate (CVws, approximately 15%, multijoint leg extension press......OBJECTIVE: The purpose of this study was to test the reproducibility and clinical feasibility of three functional performance measures and five single-joint or multijoint muscle power measures. DESIGN: Twenty patients with a mean age of 68.7 ± 7.2 yrs with severe hip or knee osteoarthritis were...... assessed for test-retest reliability and agreement on two occasions 1 wk apart. The outcomes were maximal single-joint muscle power (hip extension/abduction and knee extension/flexion), maximal muscle power during multijoint leg extension press, and functional performance measures (20-m walk, five...

Malposition of the tibial tubercle during flexion in knees with patellofemoral arthritis

International Nuclear Information System (INIS)

Nagamine, R.; Miura, H.; Tanaka, K.; Urabe, K.; Iwamoto, Y.; Inoue, Y.; Okamoto, Y.; Nishizawa, M.

1997-01-01

Objective. To assess the mechanisms contributing to the induction of patellofemoral arthritis (PF-OA). Design and patients. A computed tomography scan was taken at three levels of the lower extremity in full extension and at 30 of flexion. The cuts were superimposed and 12 parameters were compared in 17 PF-OA knees and 27 normal knees to assess the rotation angle of the tibial tubercle. Results. Although the tibial tubercle was in almost the same position in full extensioin in the normal and PF-OA knees, it was positioned significantly laterally at 30 of flexion in PF-OA knees. Also the articular surface of the lateral femoral condyle was significantly narrower or steeper in PF-OA knees. Conclusion. Anatomic variations and mechanical abnormalities were identified in the PF-OA knees. (orig.)

Effects of Prophylactic Knee Bracing on Lower Limb Kinematics, Kinetics, and Energetics During Double-Leg Drop Landing at 2 Heights.

Science.gov (United States)

Ewing, Katie A; Begg, Rezaul K; Galea, Mary P; Lee, Peter V S

2016-07-01

Anterior cruciate ligament (ACL) injuries commonly occur during landing maneuvers. Prophylactic knee braces were introduced to reduce the risk of ACL injuries, but their effectiveness is debated. We hypothesized that bracing would improve biomechanical factors previously related to the risk of ACL injuries, such as increased hip and knee flexion angles at initial contact and at peak vertical ground-reaction force (GRF), increased ankle plantar flexion angles at initial contact, decreased peak GRFs, and decreased peak knee extension moment. We also hypothesized that bracing would increase the negative power and work of the hip joint and would decrease the negative power and work of the knee and ankle joints. Controlled laboratory study. Three-dimensional motion and force plate data were collected from 8 female and 7 male recreational athletes performing double-leg drop landings from 0.30 m and 0.60 m with and without a prophylactic knee brace. GRFs, joint angles, moments, power, and work were calculated for each athlete with and without a knee brace. Prophylactic knee bracing increased the hip flexion angle at peak GRF by 5.56° (P knee flexion angle at peak GRF by 4.75° (P = .001), and peak hip extension moment by 0.44 N·m/kg (P knee and ankle. No differences in peak GRFs and peak knee extension moment were observed with bracing. The application of a prophylactic knee brace resulted in improvements in important biomechanical factors associated with the risk of ACL injuries. Prophylactic knee braces may help reduce the risk of noncontact knee injuries in recreational and professional athletes while playing sports. Further studies should investigate different types of prophylactic knee braces in conjunction with existing training interventions so that the sports medicine community can better assess the effectiveness of prophylactic knee bracing. © 2016 The Author(s).

Bilateral assessment of knee muscle relationships in healthy adults

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Gislaine Regina Santos dos Santos

2014-09-01

Full Text Available Asymmetric performance of flexor and extensor muscles of the knee may be a risk factor for knee injuries, especially the anterior cruciate ligament. Additionally, asymmetries in power and work may have correlations with fatigue and performance during functional tasks. Among untrained individuals, such asymmetries may be of potential interest for training prescription. Here, we investigated the bilateral performance of knee flexors and extensors muscle groups of untrained individuals. We quantified the torque-angle and torque-velocity relationships, as well as work, power and asymmetry indexes in 20 untrained male (25 ± 4 years old; height 1.74 ± 0.05 m; body mass 76 ± 9 kg. No significant asymmetry was observed for torque-angle and torque-velocity relationships, work and power output for knee flexor and extensor muscle groups (p < .05. Our results suggest that untrained male present symmetry in the knee flexion and extension bilateral performance. Changes in this behavior due to physical training must be monitored.

Knee injury and Osteoarthritis Outcome Score (KOOS – validation and comparison to the WOMAC in total knee replacement

Directory of Open Access Journals (Sweden)

Roos Ewa M

2003-05-01

Full Text Available Abstract Background The Knee injury and Osteoarthritis Outcome Score (KOOS is an extension of the Western Ontario and McMaster Universities Osteoarthrtis Index (WOMAC, the most commonly used outcome instrument for assessment of patient-relevant treatment effects in osteoarthritis. KOOS was developed for younger and/or more active patients with knee injury and knee osteoarthritis and has in previous studies on these groups been the more responsive instrument compared to the WOMAC. Some patients eligible for total knee replacement have expectations of more demanding physical functions than required for daily living. This encouraged us to study the use of the Knee injury and Osteoarthritis Outcome Score (KOOS to assess the outcome of total knee replacement. Methods We studied the test-retest reliability, validity and responsiveness of the Swedish version LK 1.0 of the KOOS when used to prospectively evaluate the outcome of 105 patients (mean age 71.3, 66 women after total knee replacement. The follow-up rates at 6 and 12 months were 92% and 86%, respectively. Results The intraclass correlation coefficients were over 0.75 for all subscales indicating sufficient test-retest reliability. Bland-Altman plots confirmed this finding. Over 90% of the patients regarded improvement in the subscales Pain, Symptoms, Activities of Daily Living, and knee-related Quality of Life to be extremely or very important when deciding to have their knee operated on indicating good content validity. The correlations found in comparison to the SF-36 indicated the KOOS measured expected constructs. The most responsive subscale was knee-related Quality of Life. The effect sizes of the five KOOS subscales at 12 months ranged from 1.08 to 3.54 and for the WOMAC from 1.65 to 2.56. Conclusion The Knee injury and Osteoarthritis Outcome Score (KOOS is a valid, reliable, and responsive outcome measure in total joint replacement. In comparison to the WOMAC, the KOOS improved validity

Comparison of the angles and corresponding moments in the knee and hip during restricted and unrestricted squats.

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Lorenzetti, Silvio; Gülay, Turgut; Stoop, Mirjam; List, Renate; Gerber, Hans; Schellenberg, Florian; Stüssi, Edgar

2012-10-01

The aim of this study was to compare the angles and corresponding moments in the knee and hip during squats. Twenty subjects performed restricted and unrestricted squats with barbell loads that were 0, ¼, and ½ their body weight. The experimental setup consisted of a motion capture system and 2 force plates. The moments were calculated using inverse dynamics. During the unrestricted squats, the maximum moments in the knee were significantly higher, and those in the hip were significantly lower than during restricted squats. At the lowest position, the maximum knee flexion angles were approximately 86° for the restricted and approximately 106° for the unrestricted techniques, whereas the maximum hip flexion angle was between 95° and 100°. The higher moments in the hip during restricted squats suggest a higher load of the lower back. Athletes who aim to strengthen their quadriceps should consider unrestricted squats because of the larger knee load and smaller back load.

Voluntary enhanced cocontraction of hamstring muscles during open kinetic chain leg extension exercise: its potential unloading effect on the anterior cruciate ligament.

Science.gov (United States)

Biscarini, Andrea; Benvenuti, Paolo; Botti, Fabio M; Brunetti, Antonella; Brunetti, Orazio; Pettorossi, Vito E

2014-09-01

A number of research studies provide evidence that hamstring cocontraction during open kinetic chain knee extension exercises enhances tibiofemoral (TF) stability and reduces the strain on the anterior cruciate ligament. To determine the possible increase in hamstring muscle coactivation caused by a voluntary cocontraction effort during open kinetic chain leg-extension exercises, and to assess whether an intentional hamstring cocontraction can completely suppress the anterior TF shear force during these exercises. Descriptive laboratory study. Knee kinematics as well as electromyographic activity in the semitendinosus (ST), semimembranosus (SM), biceps femoris (BF), and quadriceps femoris muscles were measured in 20 healthy men during isotonic leg extension exercises with resistance (R) ranging from 10% to 80% of the 1-repetition maximum (1RM). The same exercises were also performed while the participants attempted to enhance hamstring coactivation through a voluntary cocontraction effort. The data served as input parameters for a model to calculate the shear and compressive TF forces in leg extension exercises for any set of coactivation patterns of the different hamstring muscles. For R≤ 40% 1RM, the peak coactivation levels obtained with intentional cocontraction (l) were significantly higher (P hamstring muscle, maximum level l was reached at R = 30% 1RM, corresponding to 9.2%, 10.5%, and 24.5% maximum voluntary isometric contraction (MVIC) for the BF, ST, and SM, respectively, whereas the ratio l/l 0 reached its maximum at R = 20% 1RM and was approximately 2, 3, and 4 for the BF, SM, and ST, respectively. The voluntary enhanced coactivation level l obtained for R≤ 30% 1RM completely suppressed the anterior TF shear force developed by the quadriceps during the exercise. In leg extension exercises with resistance R≤ 40% 1RM, coactivation of the BF, SM, and ST can be significantly enhanced (up to 2, 3, and 4 times, respectively) by a voluntary hamstring

MRI performed on dedicated knee coils is inaccurate for the measurement of tibial tubercle trochlear groove distance

International Nuclear Information System (INIS)

Aarvold, A.; Pope, A.; Sakthivel, V.K.; Ayer, R.V.

2014-01-01

Tibial tubercle trochlear groove distance (TTD) is a significant factor in patello-femoral instability. Initially described on CT scans with the knee in full extension, the measurement has been validated on MR scans. Dedicated knee MRI coils have subsequently superseded both CT and MRI body coils for knee imaging. However, the knee rests in partial flexion within the dedicated knee coil. The objective of this study is to investigate whether images from dedicated knee MRI coils produce different TTD measurements from MR body coils. Thirty-two symptomatic knees (27 patients) had simultaneous knee MR scans performed in both a dedicated knee coil and a body coil. TTD measurements were independently compared to assess whether the coil type used affected TTD. Patients' ages ranged from 10 to 27 years (mean 15 years). Mean TTD in the dedicated knee coil (partially flexed knee) was 11.3 mm compared with 19.9 mm in the body coil (that permits full knee extension). The mean difference was 8.6 mm, which was highly significant (p < 0.0001, unpaired t test). Inter-rater correlation co-efficient was 96 %. Of the knees that recorded a ''normal'' TTD on the dedicated knee coil, 60-100 % recorded a ''pathological'' TTD on body coil images, depending on which diagnostic value for ''normal'' cut-off was used. This study has identified a highly significant difference in TTD measurement when knees are scanned in a dedicated knee coil with the knee partially flexed, compared with an MR body coil. It is critical for surgeons and radiologists managing patello-femoral instability to appreciate this profound difference. TTD measurement taken from knees scanned in dedicated knee coils may lead to patients being falsely re-assured or erroneously denied surgery. (orig.)

Patient-controlled oral analgesia for postoperative pain management following total knee replacement.

Science.gov (United States)

Kastanias, Patti; Gowans, Sue; Tumber, Paul S; Snaith, Kianda; Robinson, Sandra

2010-01-01

To investigate whether patient-controlled oral analgesia (PCOA) used by individuals receiving a total knee replacement could reduce pain, increase patient satisfaction, reduce opioid use and/or reduce opioid side effects when compared with traditional nurse (RN)-administered oral analgesia. Patients who underwent an elective total knee replacement at a quaternary care centre (Toronto Western Hospital, Toronto, Ontario) were randomly assigned to either PCOA or RN-administered short-acting oral opioids on postoperative day 2. Subjects in the RN group called the RN to receive their prescribed short-acting opioid. Subjects in the PCOA group kept a single dose of their prescribed oral opioid at their bedside and took this dose when they felt they needed it, to a maximum of one dose every 2 h. Study outcomes, collected on postoperative day 2, included pain (measured by the Brief Pain Inventory - Short Form), patient satisfaction (measured by the Pain Outcome Questionnaire Satisfaction subscale - component II), opioid use (oral morphine equivalents), opioid side effects (nausea, pruritus and/or constipation) and knee measures (maximum passive knee flexion and pain at maximum passive knee flexion, performed on the operative knee). Study outcomes were analyzed twice. First, for a subset of 73 subjects who remained in their randomly assigned group (PCOA group, n=36; RN group, n=37), randomized analyses were performed. Second, for the larger sample of 88 subjects who were categorized by their actual method of receiving oral opioids (PCOA group, n=41; RN group, n=47), as-treated analyses were performed. There were no differences in study outcomes between the PCOA and RN groups in either analysis. PCOA was not superior to RN administration on study outcomes. However, PCOA did not increase opioid use or pain. PCOA remains an important element in the patient-centred care facility.

Clinical practice guidelines for rest orthosis, knee sleeves, and unloading knee braces in knee osteoarthritis.

Science.gov (United States)

Beaudreuil, Johann; Bendaya, Samy; Faucher, Marc; Coudeyre, Emmanuel; Ribinik, Patricia; Revel, Michel; Rannou, François

2009-12-01

To develop clinical practice guidelines concerning the use of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis. The French Physical Medicine and Rehabilitation Society (SOFMER) methodology, associating a systematic literature review, collection of everyday clinical practice, and external review by multidisciplinary expert panel, was used. Few high-level studies of bracing for knee osteoarthritis were found. No evidence exists for the effectiveness of rest orthosis. Evidence for knee sleeves suggests that they decrease pain in knee osteoarthritis, and their use is associated with subjective improvement. These actions do not appear to depend on a local thermal effect. The effectiveness of knee sleeves for disability is not demonstrated for knee osteoarthritis. Short- and mid-term follow-up indicates that valgus knee bracing decreases pain and disability in medial knee osteoarthritis, appears to be more effective than knee sleeves, and improves quality of life, knee proprioception, quadriceps strength, and gait symmetry, and decreases compressive loads in the medial femoro-tibial compartment. However, results of response to valgus knee bracing remain inconsistent; discomfort and side effects can result. Thrombophlebitis of the lower limbs has been reported with the braces. Braces, whatever kind, are infrequently prescribed in clinical practice for osteoarthritis of the lower limbs. Modest evidence exists for the effectiveness of bracing--rest orthosis, knee sleeves and unloading knee braces--for knee osteoarthritis, with only low level recommendations for its use. Braces are prescribed infrequently in French clinical practice for osteoarthritis of the knee. Randomized clinical trials concerning bracing in knee osteoarthritis are still necessary.

Effect of knee joint angle on neuromuscular activation of the vastus intermedius muscle during isometric contraction.

Science.gov (United States)

Watanabe, K; Akima, H

2011-12-01

The purpose of this study was to compare the relationship between surface electromyography (EMG) and knee joint angle of the vastus intermedius muscle (VI) with the synergistic muscles in the quadriceps femoris (QF) muscle group. Fourteen healthy men performed maximal voluntary contractions during isometric knee extension at four knee joint angles from 90°, 115°, 140°, and 165° (180° being full extension). During the contractions, surface EMG was recorded at four muscle components of the QF muscle group: the VI, vastus lateralis (VL), vastus medialis (VM), and rectus femoris (RF) muscles. The root mean square of the surface EMG at each knee joint angle was calculated and normalized by that at a knee joint angle of 90° for individual muscles. The normalized RMS of the VI muscle was significantly lower than those of the VL and RF muscles at the knee joint angles of 115° and 165° and those of the VL, VM, and RF muscles at the knee joint angle of 140° (Pneuromuscular activation of the VI muscle is regulated in a manner different from the alteration of the knee joint angle compared with other muscle components of the QF muscle group. © 2011 John Wiley & Sons A/S.

The influence of a powered knee-ankle-foot orthosis on walking in poliomyelitis subjects: A pilot study.

Science.gov (United States)

Arazpour, Mokhtar; Moradi, Alireza; Samadian, Mohammad; Bahramizadeh, Mahmood; Joghtaei, Mahmoud; Ahmadi Bani, Monireh; Hutchins, Stephen W; Mardani, Mohammad A

2016-06-01

Traditionally, the anatomical knee joint is locked in extension when walking with a conventional knee-ankle-foot orthosis. A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine differences of the powered knee-ankle-foot orthosis compared to a locked knee-ankle-foot orthosis in kinematic data and temporospatial parameters during ambulation. Quasi-experimental design. Subjects with poliomyelitis (n = 7) volunteered for this study and undertook gait analysis with both the powered and the conventional knee-ankle-foot orthoses. Three trials per orthosis were collected while each subject walked along a 6-m walkway using a calibrated six-camera three-dimensional video-based motion analysis system. Walking with the powered knee-ankle-foot orthosis resulted in a significant reduction in both walking speed and step length (both 18%), but a significant increase in stance phase percentage compared to walking with the conventional knee-ankle-foot orthosis. Cadence was not significantly different between the two test conditions (p = 0.751). There was significantly higher knee flexion during swing phase and increased hip hiking when using the powered orthosis. The new powered orthosis permitted improved knee joint kinematic for knee-ankle-foot orthosis users while providing knee support in stance and active knee motion in swing in the gait cycle. Therefore, the new powered orthosis provided more natural knee flexion during swing for orthosis users compared to the locked knee-ankle-foot orthosis. This orthosis has the potential to improve knee joint kinematics and gait pattern in poliomyelitis subjects during walking activities. © The International Society for Prosthetics and Orthotics 2015.

Mechanical characterization and validation of poly (methyl methacrylate)/multi walled carbon nanotube composite for the polycentric knee joint.

Science.gov (United States)

Arun, S; Kanagaraj, S

2015-10-01

Trans femoral amputation is one of the most uncomfortable surgeries in patient׳s life, where the prosthesis consisting of a socket, knee joint, pylon and foot is used to do the walking activities. The artificial prosthetic knee joint imitates the functions of human knee to achieve the flexion-extension for the above knee amputee. The objective of present work is to develop a light weight composite material for the knee joint to reduce the metabolic cost of an amputee. Hence, an attempt was made to study the mechanical properties of multi walled carbon nanotubes (MWCNT) reinforced Poly (methyl methacrylate) (PMMA) prepared through melt mixing technique and optimize the concentration of reinforcement. The PMMA nanocomposites were prepared by reinforcing 0, 0.1, 0.2, 0.25, 0.3 and 0.4 wt% of MWCNT using injection moulding machine via twin screw extruder. It is observed that the tensile and flexural strength of PMMA, which were studied as per ASTM D638 and D790, respectively, were increased by 32.9% and 26.3% till 0.25 wt% reinforcement of MWCNT. The experimental results of strength and modulus were compared with theoretical prediction, where a good correlation was noted. It is concluded that the mechanical properties of PMMA were found to be increased to maximum at 0.25 wt% reinforcement of MWCNT, where the Pukanszky model and modified Halpin-Tsai model are suggested to predict the strength and modulus, respectively, of the PMMA/MWCNT composite, which can be opted as a suitable materiel for the development of polycentric knee joint. Copyright © 2015 Elsevier Ltd. All rights reserved.

Malposition of the tibial tubercle during flexion in knees with patellofemoral arthritis

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Nagamine, R.; Miura, H.; Tanaka, K.; Urabe, K.; Iwamoto, Y. [Department of Orthopaedic Surgery, Kyushu Univ. (Japan); Inoue, Y.; Okamoto, Y.; Nishizawa, M. [Department of Orthopaedic Surgery, JR Kyushu Hospital, Kitakyushu City (Japan)

1997-10-01

Objective. To assess the mechanisms contributing to the induction of patellofemoral arthritis (PF-OA). Design and patients. A computed tomography scan was taken at three levels of the lower extremity in full extension and at 30 of flexion. The cuts were superimposed and 12 parameters were compared in 17 PF-OA knees and 27 normal knees to assess the rotation angle of the tibial tubercle. Results. Although the tibial tubercle was in almost the same position in full extensioin in the normal and PF-OA knees, it was positioned significantly laterally at 30 of flexion in PF-OA knees. Also the articular surface of the lateral femoral condyle was significantly narrower or steeper in PF-OA knees. Conclusion. Anatomic variations and mechanical abnormalities were identified in the PF-OA knees. (orig.) With 8 figs., 1 tab., 11 refs.

Effect of whole body vibration exercise on muscle strength and proprioception in females with knee osteoarthritis

DEFF Research Database (Denmark)

Trans, T; Aaboe, J; Henriksen, M

2009-01-01

status was measured using WOMAC. It was found that muscle strength increased significantly (pIsometric knee-extension significantly increased (p=0.021) in VibM compared to Con. TDPM was significantly improved (p=0.033) in VibF compared to Con, while there was a tendency......The purpose of this study was to assess the effect of whole body vibration (WBV) exercise on muscle strength and proprioception in female patients with osteoarthritis in the knee (knee-OA). A single blinded, randomised, controlled trial was performed in an outpatient clinic on 52 female patients...... groups trained twice a week for 8 weeks, with a progressively increasing intensity. The WBV groups performed unloaded static WBV exercise. The following were measured: knee muscle strength (extension/flexion) and proprioception (threshold for detection of passive movement (TDPM)). Self-reported disease...

Barriers for guideline adherence in knee osteoarthritis care: A qualitative study from the patients' perspective

NARCIS (Netherlands)

Spitaels, D.; Vankrunkelsven, P.; Desfosses, J.; Luyten, F.; Verschueren, S.; Assche, D. Van; Aertgeerts, B.; Hermens, R.P.

2017-01-01

RATIONALE, AIMS AND OBJECTIVES: Guidelines for patients with knee osteoarthritis (OA) are suboptimally implemented in clinical care. To improve guideline adherence, patients' perceived barriers and facilitators in current care were investigated. METHODS: Eleven patients with knee OA were extensively

Influence of knee joint position and sex on vastus medialis regional architecture.

Science.gov (United States)

Gallina, Alessio; Render, Jacqueline N; Santos, Jacquelyne; Shah, Hershal; Taylor, Dayna; Tomlin, Travis; Garland, S Jayne

2018-06-01

Ultrasound imaging was used to investigate vastus medialis (VM) architecture in 10 males and 10 females at different knee angles. Increase in muscle thickness occurs predominantly when the knee angle is changed from 0° (full extension) and 45° (p Sex differences in the VM architecture can be observed in the distal (p 0.11).

Influence of hamstring muscles extensibility on spinal curvatures and pelvic tilt in highly trained cyclists.

Science.gov (United States)

Muyor, José M; Alacid, Fernando; López-Miñarro, Pedro A

2011-09-01

The purpose of this study was to determine the influence of hamstring muscles extensibility in standing, maximal trunk flexion with knees extended and on the bicycle in lower handlebar-hands position of highly trained cyclists. Ninety-six cyclists were recruited for the study (mean ± SD, age: 30.36 ± 5.98 years). Sagittal spinal curvatures and pelvic tilt were measured in the standing position, maximal trunk flexion with knees extended (sit-and-reach test) and while sitting on a bicycle in lower handlebar-hand position using a Spinal Mouse system. Hamstring muscles extensibility was determined in both legs by passive straight leg raise test (PSLR). The sample was divided into three groups according to PSLR angle: (1) reduced extensibility (PSLR hamstring extensibility group (PSLR = 80º - 90º; n = 35), and (3) high hamstring extensibility (PSLR = > 90º; n = 31). ANOVA analysis showed significant differences among groups for thoracic (p hamstring muscles extensibility influence the thoracic and pelvic postures when maximal trunk flexion with knees extended is performed, but not when cyclists are seated on their bicycles.

Comparison of quantitative evaluation between cutaneous and transosseous inertial sensors in anterior cruciate ligament deficient knee: A cadaveric study.

Science.gov (United States)

Murase, Atsunori; Nozaki, Masahiro; Kobayashi, Masaaki; Goto, Hideyuki; Yoshida, Masahito; Yasuma, Sanshiro; Takenaga, Tetsuya; Nagaya, Yuko; Mizutani, Jun; Okamoto, Hideki; Iguchi, Hirotaka; Otsuka, Takanobu

2017-09-01

Recently several authors have reported on the quantitative evaluation of the pivot-shift test using cutaneous fixation of inertial sensors. Before utilizing this sensor for clinical studies, it is necessary to evaluate the accuracy of cutaneous sensor in assessing rotational knee instability. To evaluate the accuracy of inertial sensors, we compared cutaneous and transosseous sensors in the quantitative assessment of rotational knee instability in a cadaveric setting, in order to demonstrate their clinical applicability. Eight freshly frozen human cadaveric knees were used in this study. Inertial sensors were fixed on the tibial tuberosity and directly fixed to the distal tibia bone. A single examiner performed the pivot shift test from flexion to extension on the intact knees and ACL deficient knees. The peak overall magnitude of acceleration and the maximum rotational angular velocity in the tibial superoinferior axis was repeatedly measured with the inertial sensor during the pivot shift test. Correlations between cutaneous and transosseous inertial sensors were evaluated, as well as statistical analysis for differences between ACL intact and ACL deficient knees. Acceleration and angular velocity measured with the cutaneous sensor demonstrated a strong positive correlation with the transosseous sensor (r = 0.86 and r = 0.83). Comparison between cutaneous and transosseous sensor indicated significant difference for the peak overall magnitude of acceleration (cutaneous: 10.3 ± 5.2 m/s 2 , transosseous: 14.3 ± 7.6 m/s 2 , P sensors. Therefore, this study indicated that the cutaneous inertial sensors could be used clinically for quantifying rotational knee instability, irrespective of the location of utilization. Copyright © 2017 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

Knee Angle and Stride Length in Association with Ball Speed in Youth Baseball Pitchers

Directory of Open Access Journals (Sweden)

Bart van Trigt

2018-05-01

Full Text Available The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation 1.7 years pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.

Effects of Motor Learning on Clinical Isokinetic Test Performance in Knee Osteoarthritis Patients

Directory of Open Access Journals (Sweden)

José Messias Rodrigues-da-Silva

Full Text Available OBJECTIVES: To analyze the effects of motor learning on knee extension-flexion isokinetic performance in knee osteoarthritis patients. METHODS: One hundred and thirty-six middle-aged and older sedentary individuals (111 women, 64.3±9.9 years with knee osteoarthritis (130 patients with bilateral and who had never performed isokinetic testing underwent two bilateral knee extension-flexion (concentric-concentric isokinetic evaluations (5 repetitions at 60°/sec. The tests were first performed on the dominant leg with 2 min of recovery between test, and following a standardized warm-up that included 3 submaximal isokinetic repetitions. The same procedure was repeated on the non-dominant leg. The peak torque, peak torque adjusted for the body weight, total work, coefficient of variation and agonist/antagonist ratio were compared between tests. RESULTS: Patients showed significant improvements in test 2 compared to test 1, including higher levels of peak torque, peak torque adjusted for body weight and total work, as well as lower coefficients of variation. The agonist/antagonist relationship did not significantly change between tests. No significant differences were found between the right and left legs for all variables. CONCLUSION: The results suggest that performing two tests with a short recovery (2 min between them could be used to reduce motor learning effects on clinical isokinetic testing of the knee joint in knee osteoarthritis patients.

Influência do alongamento dos músculos isquiostibial e retofemoral no pico de torque e potência máxima do joelho Influence of stretching hamstring and quadriceps femoral muscles on knee peak torque and maximum power

Directory of Open Access Journals (Sweden)

Gabriel Peixoto Leão Almeida

2009-12-01

the four-week study, as to knee range of motion (ROM flexion and extension, as well as to isokinetic dynamometry; variables analysed were knee ROM, peak torque and maximum power. Significant mean ROM differences were found between the three groups (p0.05. A and B groups showed increased ROM at the post-test, and only the C group showed significant increase in all isokinetic variables (p<0.05. Results then suggest that PNF stretching, performed with adequate duration and intensity, may be done before sports practice with no decrease in muscle strength.

Acute effects of anterior thigh foam rolling on hip angle, knee angle, and rectus femoris length in the modified Thomas test

Directory of Open Access Journals (Sweden)

Andrew D. Vigotsky

2015-09-01

Full Text Available Background. Foam rolling has been shown to acutely increase range of motion (ROM during knee flexion and hip flexion with the experimenter applying an external force, yet no study to date has measured hip extensibility as a result of foam rolling with controlled knee flexion and hip extension moments. The purpose of this study was to investigate the acute effects of foam rolling on hip extension, knee flexion, and rectus femoris length during the modified Thomas test.Methods. Twenty-three healthy participants (male = 7; female = 16; age = 22 ± 3.3 years; height = 170 ± 9.18 cm; mass = 67.7 ± 14.9 kg performed two, one-minute bouts of foam rolling applied to the anterior thigh. Hip extension and knee flexion were measured via motion capture before and after the foam rolling intervention, from which rectus femoris length was calculated.Results. Although the increase in hip extension (change = +1.86° (+0.11, +3.61; z(22 = 2.08; p = 0.0372; Pearson’s r = 0.43 (0.02, 0.72 was not due to chance alone, it cannot be said that the observed changes in knee flexion (change = −1.39° (−5.53, +2.75; t(22 = −0.70; p = 0.4933; Cohen’s d = − 0.15 (−0.58, 0.29 or rectus femoris length (change = −0.005 (−0.013, +0.003; t(22 = −1.30; p = 0.2070; Cohen’s d = − 0.27 (−0.70, 0.16 were not due to chance alone.Conclusions. Although a small change in hip extension was observed, no changes in knee flexion or rectus femoris length were observed. From these data, it appears unlikely that foam rolling applied to the anterior thigh will improve passive hip extension and knee flexion ROM, especially if performed in combination with a dynamic stretching protocol.

Effect of high-dose preoperative methylprednisolone on pain and recovery after total knee arthroplasty: a randomized, placebo-controlled trial

DEFF Research Database (Denmark)

Lunn, Troels; Kristensen, Billy Bjarne; Andersen, Lasse

2011-01-01

Total knee arthroplasty (TKA) is associated with severe pain and inflammation despite an extensive multimodal analgesic approach, but the effect of high-dose glucocorticoid administration has not been studied.......Total knee arthroplasty (TKA) is associated with severe pain and inflammation despite an extensive multimodal analgesic approach, but the effect of high-dose glucocorticoid administration has not been studied....

Does post-operative knee awareness differ between knees in bilateral simultaneous total knee arthroplasty? Predictors of high or low knee awareness

DEFF Research Database (Denmark)

Nielsen, Katrine Abildgaard; Thomsen, Morten Grove; Latifi, Roshan

2016-01-01

PURPOSE: To evaluate the difference in post-operative knee awareness between knees in patients undergoing bilateral simultaneous total knee arthroplasty (TKA) and to assess factors predicting high or low knee awareness. METHODS: This study was conducted on 99 bilateral simultaneous TKAs performed...... at our institution from 2008 to 2012. All patients received one set of questionnaires [Forgotten Joint Score (FJS) and Oxford Knee Score (OKS)] for each knee. Based on the FJS, the patients' knees were divided into two groups: "best" and "worst" knees. The median of the absolute difference in FJS and OKS...... within each patient was calculated. Multivariate linear regression was performed to identify factors affecting FJS. RESULTS: The difference between knees was 1 point (CI 0-5) for the FJS and 1 point (CI 0-2) for the OKS. The FJS for females increased (decreasing awareness) with increasing age. Males had...

Total knee arthroplasty for severe valgus knee deformity.

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

2014-01-01

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. 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-III 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. The mean HSS knee score were improved from 50.33 ± 11.60 to 90.06 ± 3.07 (P managed with rivaroxaban and thrombo-embolic deterrent stockings. There was no incidence of pulmonary embolism. Post-operative patient satisfaction was 80.7 ± 10.4 points in the groups. Prosthetic survival rate was 100% at mean 10 years postoperative. Not only hinged implants can be successfully used in variant-III valgus knees. As our results show, if proper ligament balancing techniques are used and proper ligament balance is attained, the knee may not require the use of a more constrained components. Our results also present alternative implant choices for severe knee deformities.

Posterior tibial slope impacts intraoperatively measured mid-flexion anteroposterior kinematics during cruciate-retaining total knee arthroplasty.

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Dai, Yifei; Cross, Michael B; Angibaud, Laurent D; Hamad, Cyril; Jung, Amaury; Jenny, Jean-Yves

2018-02-23

Posterior tibial slope (PTS) for cruciate-retaining (CR) total knee arthroplasty (TKA) is usually pre-determined by the surgeon. Limited information is available comparing different choices of PTS on the kinematics of the CR TKA, independent of the balancing of the extension gap. This study hypothesized that with the same balanced extension gap, the choice of PTS significantly impacts the intraoperatively measured kinematics of CR TKA. Navigated CR TKAs were performed on seven fresh-frozen cadavers with healthy knees and intact posterior cruciate ligament (PCL). A custom designed tibial baseplate was implanted to allow in situ modification of the PTS, which altered the flexion gap but maintained the extension gap. Knee kinematics were measured by performing passive range of motion (ROM) tests from full extension to 120° of flexion on the intact knee and CR TKAs with four different PTSs (1°, 4°, 7°, and 10°). The measured kinematics were compared across test conditions to assess the impact of PTS. With a consistent extension gap, the change of PTS had significant impact on the anteroposterior (AP) kinematics of the CR TKA knees in mid-flexion range (45°-90°), but not so much for the high-flexion range (90°-120°). No considerable impacts were found on internal/external (I/E) rotation and hip-knee-ankle (HKA) angle. However, the findings on the individual basis suggested the impact of PTS on I/E rotation and HKA angle may be patient-specific. The data suggested that the choice of PTS had the greatest impact on the mid-flexion AP translation among the intraoperatively measured kinematics. This impact may be considered while making surgical decisions in the context of AP kinematics. When using a tibial component designed with "center" pivoting PTS, a surgeon may be able to fine tune the PTS to achieve proper mid-flexion AP stability.

MR arthrography of the knee

International Nuclear Information System (INIS)

Kramer, J.; Engel, A. Jr.; Stiglbauer, R. Jr.; Prayer, L. Jr.; Hajek, P. Jr.; Imhof, H.

1991-01-01

This paper demonstrates the diagnostic value of MR arthrography in the assessment of cartilaginous lesions, including osteochondritis dissecans. One hundred thirty-two knees of 125 patients were examined with MR arthrography performed on a 1.5-T magnet with a knee resonator. T1-weighted spin-echo and T2*-weighted three-dimensional gradient-echo sequences were obtained after intraarticular administration of 40 mL of 2-mmol GD-DTPA solution. Seventy-five patients were also imaged without contrast agent. The description of the articular surface was classified into four types: I, normal cartilage surface and thickness; II, surface normal or slightly irregular; III, severe surface irregularities and cartilage defects; and IV, extensive cartilage defects, scar formation. MR findings were correlated with those of arthroscopy/arthrotomy (n = 75)

Knee osteoarthritis image registration: data from the Osteoarthritis Initiative

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Galván-Tejada, Jorge I.; Celaya-Padilla, José M.; Treviño, Victor; Tamez-Peña, José G.

2015-03-01

Knee osteoarthritis is a very common disease, in early stages, changes in joint structures are shown, some of the most common symptoms are; formation of osteophytes, cartilage degradation and joint space reduction, among others. Based on a joint space reduction measurement, Kellgren-Lawrence grading scale, is a very extensive used tool to asses radiological OA knee x-ray images, based on information obtained from these assessments, the objective of this work is to correlate the Kellgren-Lawrence score to the bilateral asymmetry between knees. Using public data from the Osteoarthritis initiative (OAI), a set of images with different Kellgren-Lawrencescores were used to determine a relationship of Kellgren-Lawrence score and the bilateral asymmetry, in order to measure the asymmetry between the knees, the right knee was registered to match the left knee, then a series of similarity metrics, mutual information, correlation, and mean squared error where computed to correlate the deformation (mismatch) of the knees to the Kellgren-Lawrence score. Radiological information was evaluated and scored by OAI radiologist groups. The results of the study suggest an association between Radiological Kellgren-Lawrence score and image registration metrics, mutual information and correlation is higher in the early stages, and mean squared error is higher in advanced stages. This association can be helpful to develop a computer aided grading tool.

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

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Saito, Akira; Akima, Hiroshi

2013-12-01

It is not understood how the knee joint angle affects the relationship between electromyography (EMG) and force of four individual quadriceps femoris (QF) muscles. The purpose of this study was to examine the effect of the knee joint angle on the EMG-force relationship of the four individual QF muscles, particularly the vastus intermedius (VI), during isometric knee extensions. Eleven healthy men performed 20-100% of maximal voluntary contraction (MVC) at knee joint angles of 90°, 120° and 150°. Surface EMG of the four QF synergists was recorded and normalized by the root mean square during MVC. The normalized EMG of the four QF synergists at a knee joint angle of 150° was significantly lower than that at 90° and 120° (P knee joint angle of 150°. Furthermore, the neuromuscular activation of the VI was the most sensitive to change in muscle length among the four QF synergistic muscles. Copyright © 2013 Elsevier Ltd. All rights reserved.

Synovial haemangioma of the knee joint: an unusual cause of knee pain in a 14-month old girl.

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Wen, D W; Tan, T J; Rasheed, S

2016-06-01

We report a histologically proven case of synovial haemangioma of the knee in a 14-month old girl who presented to the emergency department with an acute 1-day history of refusing to weight-bear on the right leg and a preceding 3-week history of a right knee lump. Physical examination revealed a non-tender, soft lump over the lateral infrapatellar region. Radiographs revealed a poorly defined soft tissue density over the infrapatellar fat pad and a suprapatellar joint effusion. Ultrasound was used to confirm the presence of a vascular soft tissue mass compatible with a synovial haemangioma within the infrapatellar fat pad which showed both intra-articular and extra-articular extension. There was good correlation of the ultrasound findings with magnetic resonance imaging (MRI), highlighting the potential clinical utility of ultrasound as an alternative imaging modality in establishing the pre-operative diagnosis and extent of a synovial haemangioma about the knee joint.

Synovial haemangioma of the knee joint: an unusual cause of knee pain in a 14-month old girl

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Wen, D.W.; Rasheed, S. [KK Women' s and Children' s Hospital, Department of Diagnostic and Interventional Imaging, Singapore (Singapore); Tan, T.J. [Changi General Hospital, Department of Radiology, Singapore (Singapore)

2016-06-15

We report a histologically proven case of synovial haemangioma of the knee in a 14-month old girl who presented to the emergency department with an acute 1-day history of refusing to weight-bear on the right leg and a preceding 3-week history of a right knee lump. Physical examination revealed a non-tender, soft lump over the lateral infrapatellar region. Radiographs revealed a poorly defined soft tissue density over the infrapatellar fat pad and a suprapatellar joint effusion. Ultrasound was used to confirm the presence of a vascular soft tissue mass compatible with a synovial haemangioma within the infrapatellar fat pad which showed both intra-articular and extra-articular extension. There was good correlation of the ultrasound findings with magnetic resonance imaging (MRI), highlighting the potential clinical utility of ultrasound as an alternative imaging modality in establishing the pre-operative diagnosis and extent of a synovial haemangioma about the knee joint. (orig.)

A MAXIMUM POWER POINT TRACKING SCHEME FOR A 1kW ...

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user

knee point of PV system under variable atmospheric conditions have been ..... of the PV generator module increases, and the maximum power output increases as well. ..... Water Pumping System” A Thesis resented to the. Faculty of California ...

Biomechanical risk factors and mechanisms of knee injury in golfers.

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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.

Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat.

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Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

2017-01-01

In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. III a.

Assessment of patient functional performance in different knee arthroplasty designs during unconstrained squat

Science.gov (United States)

Verdini, Federica; Zara, Claudio; Leo, Tommaso; Mengarelli, Alessandro; Cardarelli, Stefano; Innocenti, Bernardo

2017-01-01

Summary Background In this paper, squat named by Authors unconstrained because performed without constrains related to feet position, speed, knee maximum angle to be reached, was tested as motor task revealing differences in functional performance after knee arthroplasty. It involves large joints ranges of motion, does not compromise joint safety and requires accurate control strategies to maintain balance. Methods Motion capture techniques were used to study squat on a healthy control group (CTR) and on three groups, each characterised by a specific knee arthroplasty design: a Total Knee Arthroplasty (TKA), a Mobile Bearing and a Fixed Bearing Unicompartmental Knee Arthroplasty (respectively MBUA and FBUA). Squat was analysed during descent, maintenance and ascent phase and described by speed, angular kinematics of lower and upper body, the Center of Pressure (CoP) trajectory and muscle activation timing of quadriceps and biceps femoris. Results Compared to CTR, for TKA and MBUA knee maximum flexion was lower, vertical speed during descent and ascent reduced and the duration of whole movement was longer. CoP mean distance was higher for all arthroplasty groups during descent as higher was, CoP mean velocity for MBUA and TKA during ascent and descent. Conclusions Unconstrained squat is able to reveal differences in the functional performance among control and arthroplasty groups and between different arthroplasty designs. Considering the similarity index calculated for the variables showing statistically significance, FBUA performance appears to be closest to that of the CTR group. Level of evidence III a. PMID:29387646

Kinematic effects of inertia and friction added by a robotic knee exoskeleton after prolonged walking.

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Shirota, C; Tucker, M R; Lambercy, O; Gassert, R

2017-07-01

The capabilities of robotic gait assistive devices are ever increasing; however, their adoption outside of the lab is still limited. A critical barrier for the functionality of these devices are the still unknown mechanical properties of the human leg during dynamic conditions such as walking. We built a robotic knee exoskeleton to address this problem. Here, we present the effects of our device on the walking pattern of four subjects. We assessed the effects after a short period of acclimation as well as after a 1.5h walking protocol. We found that the knee exoskeleton decreased (towards extension) the peak hip extension and peak knee flexion of the leg with the exoskeleton, while minimally affecting the non-exoskeleton leg. Comparatively smaller changes occurred after prolonged walking. These results suggest that walking patterns attained after a few minutes of acclimation with a knee exoskeleton are stable for at least a couple of hours.

Clinical results of Hi-tech Knee II total knee arthroplasty in patients with rheumatoid athritis: 5- to 12-year follow-up

Directory of Open Access Journals (Sweden)

Yamanaka Hajime

2012-02-01

Full Text Available Abstract Background Total knee arthroplasty (TKA is a common form of treatment to relieve pain and improve function in cases of rheumatoid arthritis (RA. Good clinical outcomes have been reported with a variety of TKA prostheses. The cementless Hi-Tech Knee II cruciate-retaining (CR-type prosthesis, which has 6 fins at the anterior of the femoral component, posterior cruciate ligament (PCL retention, flat-on-flat surface component geometry, all-polyethylene patella, strong initial fixation by the center screw of the tibial base plate, 10 layers of titanium alloy fiber mesh, and direct compression molded ultra high molecular weight polyethylene (UHMWPE, is appropriate for TKA in the Japanese knee. The present study was performed to evaluate the clinical results of primary TKA in RA using the cementless Hi-Tech Knee II CR-type prosthesis. Materials and methods We performed 32 consecutive primary TKAs using cementless Hi-Tech Knee II CR-type prosthesis in 31 RA patients. The average follow-up period was 8 years 3 months. Clinical evaluations were performed according to the American Knee Society (KS system, knee score, function score, radiographic evaluation, and complications. Results The mean postoperative maximum flexion angle was 115.6°, and the KS knee score and function score improved to 88 and 70 after surgery, respectively. Complications, such as infection, occurred in 1 patient and revision surgery was performed. There were no cases of loosening in this cohort, and prosthesis survival rate was 96.9% at 12 years postoperatively. Conclusion These results suggest that TKA using the cementless Hi-Tech Knee II CR-type prosthesis is a very effective form of treatment in RA patients at 5 to 12 years postoperatively. Further long-term follow-up studies are required to determine the ultimate utility of this type of prosthesis.

MR assessment of movement and morphologic change in the menisci during knee flexion

International Nuclear Information System (INIS)

Kawahara, Y.; Uetani, M.; Fuchi, K.; Eguchi, H.; Hayashi, K.

1999-01-01

To examine movement and morphologic alteration in the menisci during knee flexion. Twenty healthy knees were imaged at 0 degrees, 45 degrees, and 90 degrees of passive non-weight-bearing flexion in the sagittal plane with MR. In each meniscus, posterior movement distance during knee flexion and the ratio of anteroposterior (a.p.) diameter at flexion to that at extension were calculated. Each meniscus moved posteriorly during knee flexion. Movement was greater in the anterior horn than in the posterior horn, and greater in the medial meniscus than in the lateral meniscus (p<0.05). The a.p. diameter of each meniscus was reduced at flexion (p<0.05). Knee flexion normally leads to posterior movement and shortening of the a.p. diameter of the menisci, which may be related to the positioning and curvature of femoral condyles at the femorotibial contact point at knee flexion

MR assessment of movement and morphologic change in the menisci during knee flexion

International Nuclear Information System (INIS)

Kawahara, Y.; Uetani, M.; Hayashi, K.; Fuchi, K.; Eguchi, H.

1999-01-01

Purpose: To examine movement and morphologic alteration in the menisci during knee flexion. Material and Methods: Twenty healthy knees were imaged at 0 , 45 , and 90 of passive non-weight-bearing flexion in the sagittal plane with MR. In each meniscus, posterior movement distance during knee flexion and the ratio of anteroposterior (a.p.) diameter at flexion to that at extension were calculated. Results: Each meniscus moved posteriorly during knee flexion. Movement was greater in the anterior horn than in the posterior horn, and greater in the medial meniscus than in the lateral meniscus (p<0.05). The a.p. diameter of each meniscus was reduced at flexion (p<0.05). Conclusion: Knee flexion normally leads to posterior movement and shortening of the a.p. diameter of the menisci, which may be related to the positioning and curvature of femoral condyles at the femorotibial contact point at knee flexion. (orig.)

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

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Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

Symptomatic versus asymptomatic knees after bilateral total knee arthroplasty: what is the difference in SPECT/CT?

Energy Technology Data Exchange (ETDEWEB)

Awengen, R.; Hirschmann, M.T. [Kantonsspital Baselland (Bruderholz, Liestal, Laufen), Department of Orthopaedic Surgery and Traumatology, Bruderholz (Switzerland); Rasch, H. [Kantonsspital Baselland (Bruderholz, Liestal, Laufen), Institute of Radiology and Nuclear Medicine, Bruderholz (Switzerland); Amsler, F. [Amsler Consulting, Basel (Switzerland)

2016-04-15

The primary purpose of this retrospective study was to evaluate the differences of bone tracer uptake (BTU) in symptomatic and asymptomatic knees after bilateral total knee arthroplasty (TKA) and identify typical BTU patterns with regards to TKA component position and alignment. A consecutive number of 37 patients after bilateral TKA were retrospectively included. The knees were grouped into symptomatic (group A) and asymptomatic (group B) knees. All patients underwent 99m-Tc-HDP-SPECT/CT. Coronal, rotational, and sagittal TKA component position was analysed in 3D reconstructed CT. BTU was anatomically localised and quantified using a validated standardized localization scheme. Maximum BTU values for each area were recorded and normalized values calculated. Signed log-rank test, chi-square test, paired t-tests, and Pearson correlations were used (p <0.05). Symptomatic TKAs were significantly more flexed and had a tendency to be more internally rotated when compared to asymptomatic ones (p < 0.05). In all regions, the mean BTU in asymptomatic knees was lower than in symptomatic knees. In both groups the highest mean BTU was found around the tibial stem (symptomatic 7.30; asymptomatic 6.30, p = 0.061) and at the tip of the tibial stem (symptomatic 5.49; asymptomatic 4.74, p = 0.062). Superior patellar regions showed higher BTU than inferior regions. The highest patellar BTU was found in the superior medial patella (symptomatic 4.99; asymptomatic 3.98, p = 0.048). The lowest BTU was found in the posterior femoral regions (flatsp, flatip, fmedsp, fmedip) (Table 3). Tibial and patellar areas showed twice as high mean BTUs than femoral areas (Fig. 3). A significant correlation of TKA component position and BTU was demonstrated. Distribution and intensity of BTU in SPECT/CT depends on TKA component position and alignment. In addition, typical BTU patterns in symptomatic and asymptomatic knees were identified. A profound knowledge of BTU pattern, TKA component position

The Functional Abilities and Maximal Vertical Jumping Height in Coper and Non-coper Anterior Cruciate Ligament-Deficient Knee

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Amin Norouzi Fashkhami

2014-06-01

Full Text Available Objectives: The aim of the present study was to compare the performance of the vertical jump task and the level of disability between the coper and non-coper athletes with an anterior cruciate ligament-minus knee. Methods: Thirty-four professional male athletes with isolated complete anterior cruciate ligament-tear (age 20-29 years and 6-12 months time past injury were recruited in this study. The subjects were allocated into the coper (n=17 and non-coper (n=17 groups according to their history of having giving way and feeling an instability in their injured knee. The maximum vertical jump height was recorded by a 6-camera Vicon motion analysis system. The functional outcomes of the subjects were assessed with use of the Persian versions of the International Knee Documentation Committee, Knee Injury and Osteoarthritis Outcome Score and Tegner Questionnaires. Results: The results revealed that the coper ACK-deficient knee subjects had a significantly higher International Knee Documentation Committee score as well as two subscales of the KOOS questionnaire including the sports (P=0.001 and the quality of life (P=0.016 than non-copers. However, the subscales of pain (P=0.0137, symptoms (P=0.353 and the activities of daily living (P=0.133 of the KOOS questionnaire did not show any significant differences between the coper and non-coper ACL-deficient knee subjects. In addition, the maximum jumping height was significantly higher in the copers too (P=0.008. Discussion: While the pain, symptoms and daily activities were not different between the two groups, a higher level of the functional abilities, sports activities, quality of life and the maximum jumping height were shown in the coper ACL-deficient knee subjects when compared to the non-copers. A deliberate evaluation of the functional abilities in ACL-deficient knee subjects might play a key role in distinguishing the coper and non-coper ACL-deficient knee subjects.

Knee Replacement

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Knee replacement is surgery for people with severe knee damage. Knee replacement can relieve pain and allow you to ... Your doctor may recommend it if you have knee pain and medicine and other treatments are not ...

Knee Injuries

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... Staying Safe Videos for Educators Search English Español Knee Injuries KidsHealth / For Teens / Knee Injuries What's in ... can do to protect them. What's in a Knee? The knee is a joint , actually the largest ...

Radiographic assessment of knee-ankle alignment after total knee arthroplasty for varus and valgus knee osteoarthritis.

Science.gov (United States)

Gao, Fuqiang; Ma, Jinhui; Sun, Wei; Guo, Wanshou; Li, Zirong; Wang, Weiguo

2017-01-01

There are unanswered questions about knee-ankle alignment after total knee arthroplasty (TKA) for varus and valgus osteoarthritis (OA) of the knee. The aim of this retrospective study was to assess knee-ankle alignment after TKA. The study consisted of 149 patients who had undergone TKA due to varus and valgus knee OA. The alignment and angles in the selected knees and ankles were measured on full-length standing anteroposterior radiographs, both pre-operatively and post-operatively. The paired t-test and Pearson's correlation tests were used for statistical analysis. The results showed that ankle alignment correlated with knee alignment both pre-operatively and postoperatively (Pknee was corrected (Pknee-ankle alignment on the non-operative side (P>0.05). These findings indicated that routine TKA could correct the varus or valgus deformity of a knee, and improve the tilt of the ankle. Ankle alignment correlated with knee alignment both pre-operatively and postoperatively. Both pre-operative knee and ankle malalignment can be simultaneously corrected following TKA. Level III. Copyright © 2016 Elsevier B.V. All rights reserved.

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

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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. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Patient Self-Assessed Passive Range of Motion of the Knee Cannot Replace Health Professional Measurements

DEFF Research Database (Denmark)

Borgbjerg, Jens; Madsen, Frank; Odgaard, Anders

2017-01-01

The purpose of this study was to investigate whether patients can accurately self-assess their knee passive range of motion (PROM). A picture-based questionnaire for patient self-assessment of knee PROM was developed and posted to patients. The self-assessed PROM from 58 patients was compared...... (≥ 10-degree flexion contracture). Surgeon- and patient-assessed knee PROM showed a mean difference (95% limits of agreement) of -2.1 degrees (-42.5 to 38.3 degrees) for flexion and -8.1 degrees (-28.8 to 12.7 degrees) for extension. The sensitivity of patient self-assessed PROM in identifying knee...

The effect of footwear adapted with a multi-curved rocker sole in conjunction with knee-ankle-foot orthoses on walking in poliomyelitis subjects: a pilot study.

Science.gov (United States)

Mojaver, Ali; Arazpour, Mokhtar; Aminian, Gholamreza; Ahmadi Bani, Monireh; Bahramizadeh, Mahmood; Sharifi, Guive; Sherafatvaziri, Arash

2017-10-01

Knee-ankle-foot orthoses (KAFOs) are used by people with poliomyelitis to ambulate. Whist advances in orthotic knee joint designs for use in KAFOs such the provision of stance control capability have proven efficacy, little attention has been paid to shoe adaptations which may also improve gait. The aim of this study was to evaluate the alteration to the kinematics and temporal-spatial parameters of gait caused by the use of heel-to-toe rocker-soled footwear when ambulating with KAFOs. Nine adults with a history of poliomyelitis who routinely wore KAFOs participated in the study. A heel-to-toe rocker sole was added to footwear and worn on the affected side. A three-dimensional motion capture system was used to quantify the resulting alteration to specific gait parameters. Maximum hip joint extension was significantly increased (p = 0.011), and hip abduction and adduction were both significantly reduced (p = 0.011 and p = 0.007, respectively) when walking with the rocker sole. A significant increase in stride length (p = 0.035) was demonstrated but there were no significant increases in either walking speed or cadence. A heel-to-toe rocker sole adaptation may be useful for walking in patients with poliomyelitis who use KAFOs. Implications for Rehabilitation The poor functionality and difficulty in walking when using an orthotic device such as a KAFO which keeps the knee locked during ambulation, plus the significant energy required to walk, are complications of orthoses using. Little evidence exists regarding the biomechanical effect of walking with a KAFO incorporating fixed knee joints, in conjunction with rocker-soled footwear. The main aim of walking with a heel-to-toe rocker sole is to facilitate forward progression of the tibia when used with an AFO or KAFO or to provide easier walking for patients who have undergone an ankle arthrodesis. In this study, a rocker sole profile adaptation produced no significant alteration to hip joint flexion

Changes in collagen metabolites in serum after cemented hip and knee arthroplasty

DEFF Research Database (Denmark)

Joerring, S; Jensen, L T

1993-01-01

Markers of types I and III collagen turnover were measured in serial blood samples collected preoperatively and 60 days after surgery in 13 patients undergoing cemented total hip arthroplasty and 11 patients undergoing cemented total knee arthroplasty. The markers were the carboxyterminal extension....... We suggest that the changes in serum PICP and serum PIIINP reflect collagen formation in healing soft connective tissue 60 days after cemented hip or knee arthroplasty....

Isometric and isokinetic muscle strength in patients with fibrositis syndrome. New characteristics for a difficult definable category of patients

DEFF Research Database (Denmark)

Jacobsen, Søren; Danneskiold-Samsøe, B

1987-01-01

A common complaint among patients with fibrositis syndrome is exhaustion and fatique. It was therefore felt desirable to evaluate the muscle strength of these patients compared with normal subjects. Maximum isometric and isokinetic strength of knee extension was measured in 15 patients and 15...... healthy matched subjects, using an isokinetic dynamometer (Cybex II). Maximum isometric strength at various knee extension angles (90 degrees, 60 degrees and 30 degrees degrees) was significantly (p less than 0.001) lower in the fibrositis group than in controls, a reduction of approximately 58......-66%. Maximum isokinetic strength at various knee extension velocities (30-240 degrees per second) was also significantly (p less than 0.01) lower in the fibrositis group than in controls, the reduction being approximately 41-51%. In conclusion, isometric and isokinetic muscle strength is found to be lower...

3D in vivo femoro-tibial kinematics of tri-condylar total knee arthroplasty during kneeling activities.

Science.gov (United States)

Nakamura, Shinichiro; Sharma, Adrija; Kobayashi, Masahiko; Ito, Hiromu; Nakamura, Kenji; Zingde, Sumesh M; Nakamura, Takashi; Komistek, Richard D

2014-01-01

Kneeling position can serve as an important posture, providing stability and balance from a standing position to sitting on the floor or vice-versa. The purpose of the current study was to determine the kinematics during kneeling activities after subjects were implanted with a tri-condylar total knee arthroplasty. Kinematics was evaluated in 54 knees using fluoroscopy and a three-dimensional model fitting approach. The average knee flexion at before contact status, at complete contact and at maximum flexion was 98.1±9.0°, 107.2±6.7°, and 139.6±12.3°, respectively. On average, there was no gross anterior displacement from before contact status to complete contact. Only slight posterior rollback motion of both condyles from complete contact to maximum flexion was observed. Three of 39 (7.7%) knees experienced anterior movement of both condyles more than 2mm from before contact status to complete contact. Reverse rotation pattern from before contact status to complete contact and then normal rotation pattern from complete contact to maximum flexion were observed. Condylar lift-off greater than 1.0 mm was observed in 45 knees (83.3%). The presence of the ball-and-socket joint articulation provides sufficient antero-posterior stability in these designs to enable the patients to kneel safely without the incidence of any dislocation. This study suggests a safe implant design for kneeling. © 2013.

Low Level Laser Therapy for chronic knee joint pain patients.

Science.gov (United States)

Nakamura, Takashi; Ebihara, Satoru; Ohkuni, Ikuko; Izukura, Hideaki; Harada, Takashi; Ushigome, Nobuyuki; Ohshiro, Toshio; Musha, Yoshiro; Takahashi, Hiroshi; Tsuchiya, Kazuaki; Kubota, Ayako

2014-12-27

Chronic knee joint pain is one of the most frequent complaints which is seen in the outpatient clinic in our medical institute. In previous studies we have reported the benefits of low level laser therapy (LLLT) for chronic pain in the shoulder joints, elbow, hand, finger and the lower back. The present study is a report on the effects of LLLT for chronic knee joint pain. Over the past 5 years, 35 subjects visited the outpatient clinic with complaints of chronic knee joint pain caused by the knee osteoarthritis-induced degenerative meniscal tear. They received low level laser therapy. A 1000 mW semi-conductor laser device was used to deliver 20.1 J/cm(2) per point in continuous wave at 830nm, and four points were irradiated per session (1 treatment) twice a week for 4 weeks. A visual analogue scale (VAS) was used to determine the effects of LLLT for the chronic pain and after the end of the treatment regimen a significant improvement was observed (pknee joint range of motion. Discussions with the patients revealed that it was important for them to learn how to avoid postures that would cause them knee pain in everyday life in order to have continuous benefits from the treatment. The present study demonstrated that 830 nm LLLT was an effective form of treatment for chronic knee pain caused by knee osteoarthritis. Patients were advised to undertake training involving gentle flexion and extension of the knee.

Neuromuscular Training Improves Lower Extremity Biomechanics Associated with Knee Injury during Landing in 11–13 Year Old Female Netball Athletes: A Randomized Control Study

Directory of Open Access Journals (Sweden)

Amanda J. Hopper

2017-11-01

Full Text Available The purpose of this study was to examine the effects of a neuromuscular training (NMT program on lower-extremity biomechanics in youth female netball athletes. The hypothesis was that significant improvements would be found in landing biomechanics of the lower-extremities, commonly associated with anterior cruciate ligament (ACL injury, following NMT. Twenty-three athletes (age = 12.2 ± 0.9 years; height = 1.63 ± 0.08 m; mass = 51.8 ± 8.5 kg completed two testing sessions separated by 7-weeks and were randomly assigned to either a experimental or control group. Thirteen athletes underwent 6-weeks of NMT, while the remaining 10 served as controls and continued their regular netball training. Three-dimensional lower-extremity kinematics and vertical ground reaction force (VGRF were measured during two landing tasks, a drop vertical jump and a double leg broad jump with a single leg landing. The experimental group significantly increased bilateral knee marker distance during the bilateral landing task at maximum knee-flexion range of motion. Knee internal rotation angle during the unilateral landing task at maximum knee flexion-extension range of motion was significantly reduced (p ≤ 0.05, g > 1.00. The experimental group showed large, significant decreases in peak vertical ground reaction force in both landing tasks (p ≤ 0.05, g > −1.30. Control participants did not demonstrate any significant pre-to-post-test changes in response to the 6-week study period. Results of the study affirm the hypothesis that a 6-week NMT program can enhance landing biomechanics associated with ACL injury in 11–13 year old female netball athletes.

Neuromuscular Training Improves Lower Extremity Biomechanics Associated with Knee Injury during Landing in 11–13 Year Old Female Netball Athletes: A Randomized Control Study

Science.gov (United States)

Hopper, Amanda J.; Haff, Erin E.; Joyce, Christopher; Lloyd, Rhodri S.; Haff, G. Gregory

2017-01-01

The purpose of this study was to examine the effects of a neuromuscular training (NMT) program on lower-extremity biomechanics in youth female netball athletes. The hypothesis was that significant improvements would be found in landing biomechanics of the lower-extremities, commonly associated with anterior cruciate ligament (ACL) injury, following NMT. Twenty-three athletes (age = 12.2 ± 0.9 years; height = 1.63 ± 0.08 m; mass = 51.8 ± 8.5 kg) completed two testing sessions separated by 7-weeks and were randomly assigned to either a experimental or control group. Thirteen athletes underwent 6-weeks of NMT, while the remaining 10 served as controls and continued their regular netball training. Three-dimensional lower-extremity kinematics and vertical ground reaction force (VGRF) were measured during two landing tasks, a drop vertical jump and a double leg broad jump with a single leg landing. The experimental group significantly increased bilateral knee marker distance during the bilateral landing task at maximum knee-flexion range of motion. Knee internal rotation angle during the unilateral landing task at maximum knee flexion-extension range of motion was significantly reduced (p ≤ 0.05, g > 1.00). The experimental group showed large, significant decreases in peak vertical ground reaction force in both landing tasks (p ≤ 0.05, g > −1.30). Control participants did not demonstrate any significant pre-to-post-test changes in response to the 6-week study period. Results of the study affirm the hypothesis that a 6-week NMT program can enhance landing biomechanics associated with ACL injury in 11–13 year old female netball athletes. PMID:29163219

Inter-Observer and Intra-Observer Reliability of Clinical Assessments in Knee Osteoarthritis

Science.gov (United States)

Maricar, Nasimah; Callaghan, Michael J; Parkes, Matthew J; Felson, David T; O’Neill, Terence W

2016-01-01

Background Clinical examination of the knee is subject to measurement error. The aim of this analysis was to determine inter- and intra-observer reliability of commonly used clinical tests in patients with knee osteoarthritis(OA). Methods We studied subjects with symptomatic knee OA who were participants in an open-label clinical trial of intra-articular steroid therapy. Following standardisation of the clinical test procedures, two clinicians assessed 25 subjects independently at the same visit, and the same clinician assessed 88 subjects over an interval period of 2–10 weeks; in both cases prior to the steroid intervention. Clinical examination included assessment of bony enlargement, crepitus, quadriceps wasting, knee effusion, joint-line and anserine tenderness and knee range of movement(ROM). Intra-class correlation coefficients(ICC), estimated kappa(κ), weighted kappa(κω) and Bland and Altman plots were used to determine inter- and intra-observer levels of agreement. Results Using Landis and Koch criteria, inter-observer kappa scores were moderate for patellofemoral joint(κ=0.53) and anserine tenderness(κ=0.48); good for bony enlargement(κ=0.66), quadriceps wasting(κ=0.78), crepitus(κ=0.78), medial tibiofemoral joint tenderness(κ=0.76), and effusion assessed by ballottement(κ=0.73) and bulge sign(κω =0.78); and excellent for lateral tibiofemoral joint tenderness(κ=1.00), flexion(ICC=0.97) and extension(ICC=0.87) ROM. Intra-observer kappa scores were moderate for lateral tibiofemoral joint tenderness(κ=0.60), good for crepitus(κ=0.78), effusion assessed by ballottement test(κ=0.77), patellofemoral joint(κ=0.66), medial tibiofemoral joint(κ=0.64) and anserine(κ=0.73) tenderness and excellent for effusion assessed by bulge sign(κω =0.83), bony enlargement(κ=0.98), quadriceps wasting(κ=0.83), flexion(ICC=0.99) and extension(ICC=0.96) ROM. Conclusion Among individuals with symptomatic knee OA, the reliability of clinical examination of the

Traditions and myths in hip and knee arthroplasty

DEFF Research Database (Denmark)

Husted, Henrik; Gromov, Kirill; Malchau, Henrik

2014-01-01

suit, a urinary catheter, and closure of the knee in extension. The safety and efficacy of tranexamic acid is supported by meta-analyses. Postoperatively, there is no evidence to support postponement of showering or postponement of changing of dressings to after 48 h. There is no evidence to recommend...

Isokinetic evaluation of knee muscles in soccer players: discriminant analysis

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Bruno Fles Mazuquin

2015-10-01

Full Text Available ABSTRACTIntroduction:Muscle activity in soccer players can be measured by isokinetic dynamometer, which is a reliable tool for assessing human performance.Objectives:To perform isokinetic analyses and to determine which variables differentiate the under-17 (U17 soccer category from the professional (PRO.Methods:Thirty four players were assessed (n=17 for each category. The isokinetic variables used for the knee extension-flexion analysis were: peak torque (Nm, total work (J, average power (W, angle of peak torque (deg., agonist/ antagonist ratio (%, measured for three velocities (60°/s, 120°/s and 300°/s, with each series containing five repetitions. Three Wilks' Lambda discriminant analyses were performed, to identify which variables were more significant for the definition of each of the categories.Results:The discriminative variables at 60°/s in the PRO category were: extension peak torque, flexion total work, extension average power and agonist/antagonist ratio; and for the U17s were: extension total work, flexion peak torque and flexion average power. At 120°/s for the PRO category the discriminant variables were: flexion peak torque and extension average power; for the U17s they were: extension total work and flexion average power. Finally at 300°/s, the variables found in the PRO and U17 categories respectively were: extension average power and extension total work.Conclusion:Isokinetic variables for flexion and extension knee muscles were able to significantly discriminate between PRO and U17 soccer players.

Evaluation of the Combined Application of Neuromuscular Electrical Stimulation and Volitional Contractions on Thigh Muscle Strength, Knee Pain and Physical Performance in Women at Risk for Knee Osteoarthritis: A Randomized Controlled Trial.

Science.gov (United States)

Rabe, Kaitlin G; Matsuse, Hiroo; Jackson, Anthony; Segal, Neil A

2018-05-28

Knee osteoarthritis (OA) is a leading cause of disability that is associated with quadriceps weakness. However, strengthening in people with or with risk factors for knee OA can be poorly tolerated. To assess the efficacy of a twelve-week low-load exercise program, using a hybrid training system (HTS) that utilizes the combination of neuromuscular electrical stimulation and volitional contractions, for improving thigh muscle strength, knee pain and physical performance in women with or with risk factors for knee OA. Randomized, single-blind, controlled trial SETTING: Exercise training laboratory PARTICIPANTS: Forty-two women, age 44-85 years, with risk factors for knee OA INTERVENTIONS: Participants randomized to 12 weeks of biweekly low-load resistance training either with HTS or on an isokinetic dynamometer (control). Maximum isokinetic knee extensor torque. Secondary measures included: maximum isokinetic knee flexor torque, knee pain (KOOS), and timed 20-meter walk and chair-stand tests. HTS and control both resulted in muscle strengthening, reduced knee pain and improved physical performance. HTS group quadriceps and hamstring strength increased by 0.06±0.04 Nm/kg (p>.05) and 0.05±0.02 Nm/kg (p=.02), respectively. Control group quadriceps and hamstring strength increased by 0.03±0.04 Nm/kg (p>.05) and 0.06±0.02 Nm/kg (p=.009), respectively. Knee pain improved by 11.9±11.5 points (pmeter walk time decreased by 1.60±2.04 seconds (p=.005) and 0.95±1.2 seconds (p=.004), and chair stand time decreased by 4.8±10.0 seconds (p>.05) and 1.9±4.7 seconds (p>.05) in the HTS and control groups, respectively. These results did not differ statistically between HTS and control groups. These results suggest HTS is effective for improving pain and physical performance in women with risk factors for knee OA. However, HTS does not appear to be superior to low-load resistance training for improving muscle strength, pain or physical function. Copyright © 2018 American

A review of experimental results at the knee

International Nuclear Information System (INIS)

Hoeorandel, Joerg R.

2006-01-01

Results of experiments investigating air showers in the energy region of the knee are summarized. The all-particle energy spectrum, the mean logarithmic mass, and the average depth of the shower maximum will be discussed. Spectra for groups of elements from air shower data are compared to results from direct measurements

Stair ascent with an innovative microprocessor-controlled exoprosthetic knee joint.

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Bellmann, Malte; Schmalz, Thomas; Ludwigs, Eva; Blumentritt, Siegmar

2012-12-01

Climbing stairs can pose a major challenge for above-knee amputees as a result of compromised motor performance and limitations to prosthetic design. A new, innovative microprocessor-controlled prosthetic knee joint, the Genium, incorporates a function that allows an above-knee amputee to climb stairs step over step. To execute this function, a number of different sensors and complex switching algorithms were integrated into the prosthetic knee joint. The function is intuitive for the user. A biomechanical study was conducted to assess objective gait measurements and calculate joint kinematics and kinetics as subjects ascended stairs. Results demonstrated that climbing stairs step over step is more biomechanically efficient for an amputee using the Genium prosthetic knee than the previously possible conventional method where the extended prosthesis is trailed as the amputee executes one or two steps at a time. There is a natural amount of stress on the residual musculoskeletal system, and it has been shown that the healthy contralateral side supports the movements of the amputated side. The mechanical power that the healthy contralateral knee joint needs to generate during the extension phase is also reduced. Similarly, there is near normal loading of the hip joint on the amputated side.

Partial knee replacement

Science.gov (United States)

... good range of motion in your knee. The ligaments in your knee are stable. However, most people with knee arthritis have a surgery called a total knee arthroplasty (TKA). Knee replacement is most often done in people age 60 ...

Interlimb communication to the knee flexors during walking in humans

DEFF Research Database (Denmark)

Stevenson, Andrew James Thomas; Geertsen, Svend Sparre; Andersen, Jacob Buus

2013-01-01

A strong coordination between the two legs is important for maintaining a symmetric gait pattern and adapting to changes in the external environment. In humans as well as animals, receptors arising from the quadriceps muscle group influence the activation of ipsilateral muscles. Moreover, strong...... contralateral spinal connections arising from quadriceps and hamstrings afferents have been shown in animal models. Therefore, the aims of the present study were to assess if such connections also exist in humans and to elucidate on the possible pathways. Contralateral reflex responses were investigated...... in the right leg following unexpected unilateral knee joint rotations during locomotion in either the flexion or extension direction. Strong reflex responses in the contralateral biceps femoris (cBF) muscle with a mean onset latency of 76 ± 6 ms were evoked only from ipsilateral knee extension joint rotations...

Early changes in muscle strength after total knee arthroplasty. A 6-month follow-up of 30 knees

DEFF Research Database (Denmark)

Lorentzen, J S; Petersen, M M; Brot, C

1999-01-01

to surgery, and after 3 and 6 months, isokinetic and isometric muscle strength in both legs were measured, using a Cybex 6000 dynamometer. Isokinetic tests showed a bilateral, significant, and progressive increase (30-53%) in flexor muscle strength most pronounced in the operated legs. Isokinetic extensor...... strength increased significantly (14-18%) in the operated legs, while in the contralateral legs, a limited increase was found. Isometric flexion strength significantly decreased in the operated knees (17%). Isometric extension strength showed a temporary decrease at 3 months, which returned...... to the preoperative level. No significant change in isometric strength was observed in the contralateral legs. The knee pain during the muscle strength measurements decreased significantly from the preoperative level, which may indicate that the substantial pain relief within 3 months after a TKA is an important...

Knee arthroscopy

Science.gov (United States)

... debridement; Meniscus repair; Lateral release; Knee surgery; Meniscus - arthroscopy; Collateral ligament - arthroscopy ... pain relief (anesthesia) may be used for knee arthroscopy surgery: Local anesthesia. Your knee may be numbed ...

Total knee arthroplasty with computer-assisted navigation: an analysis of 200 cases,

Directory of Open Access Journals (Sweden)

Marcus Vinicius Malheiros Luzo

2014-04-01

Full Text Available OBJECTIVE: to evaluate the results from surgery with computer-assisted navigation in cases of total knee arthroplasty.METHOD: a total of 196 patients who underwent total knee arthroplasty with computer-assisted navigation were evaluated. The extension and flexion spaces (gaps were evaluated during the operation and the alignment after the operation was assessed. The Knee Society Score (KSS questionnaire for assessing patient's function was applied preoperatively and postoperatively after a mean follow-up of 22 months.RESULTS: in all, 86.7% of the patients presented good alignment of the mechanical axis (less than 3◦ of varus or valgus in relation to the mechanical axis and 96.4% of the patients presented balanced flexion and extension gaps. Before the operation, 97% of the patients presented poor or insufficient KSS, but after the operation, 77.6% presented good or excellent KSS.CONCLUSION: the navigation system made it possible to achieve aligned and balanced implants, with notable functional improvement among the patients. It was found to be useful in assessing, understanding and improving knowledge in relation to performing arthroplasty procedures.

Radiographic and scintigraphic evaluation of total knee arthroplasty

International Nuclear Information System (INIS)

Schneider, R.; Soudry, M.

1986-01-01

Various radiographic and scintigraphic methods are used to supplement clinical findings in the evaluation of total knee arthroplasty and its complications. Serial roentgenograms offer reliable information for diagnosing mechanical loosening. Wide and extensive radiolucency at the cement-bone interface and shift in position and alignment of prosthetic components can be seen in almost all cases by the time revision is necessary. Radiographic abnormalities are usually not present in acute infection, but are often present in chronic infection. Bone scanning has a high sensitivity for diagnosis of infection or loosening, but is nonspecific because increased uptake is often present around asymptomatic total knee arthroplasties with normal radiographs. Differential bone and Gallium scanning and scanning with Indium 111-labeled leukocytes have a greater specificity for diagnosis of infection than does bone or Gallium scanning alone. Routine radiographic and scintigraphic studies have shown a high incidence of deep vein thrombosis in the calf after total knee arthroplasty. Clinically significant pulmonary embolization is infrequent

Clinical and biomechanical assessment of patella resurfacing in total knee arthroplasty.

Science.gov (United States)

Berti, Lisa; Benedetti, Maria Grazia; Ensini, Andrea; Catani, Fabio; Giannini, Sandro

2006-07-01

Currently there is a limited understanding of the factors influencing range of motion by comparing patellar resurfacing vs non-resurfacing in total knee arthroplasty during activities of daily living. A recent meta-analysis of patellar replacement confirms better outcome with patella resurfacing; however, the result can be influenced by many other factors, such as: component design, surgeon experience, and technical aspects of the surgery. This study compares the biomechanics of the knee in patients after total knee arthroplasty with and without patellar resurfacing during stair climbing. Forty-seven patients with total knee arthroplasty were assessed at the mean follow-up of 24 months. In all of them a posterior stabilised fixed bearing prosthesis (Optetrak PS, Exactech) was implanted. Twenty-six patients were treated without patellar resurfacing and 21 with patellar resurfacing. Clinical evaluations were performed using the International Knee Society and the Hospital for Special Surgery scores. Ten patients with patellar resurfacing and 10 patients without patellar resurfacing were also studied with motion analysis during stair climbing; 10 healthy subjects were studied for statistical comparison. Clinical passive knee flexion, International Knee Society Function and Hospital for Special Surgery scores were significantly higher in the patellar resurfacing group. During stair climbing, active knee joint range of motion during the stance phase was greater in patients with patellar resurfacing. The maximum adduction moment was significantly higher in the group without patellar resurfacing. Patients with patellar resurfacing demonstrated better clinical scores, and kinematic and kinetic data while ascending stairs.

Anterior knee pain

Science.gov (United States)

Patellofemoral syndrome; Chondromalacia patella; Runner's knee; Patellar tendinitis; Jumper's knee ... kneecap (patella) sits over the front of your knee joint. As you bend or straighten your knee, ...

Knee Arthrodesis After Failure of Knee Arthroplasty

DEFF Research Database (Denmark)

Gottfriedsen, Tinne B; Morville Schrøder, Henrik; Odgaard, Anders

2016-01-01

BACKGROUND: Arthrodesis is considered a salvage procedure after failure of a knee arthroplasty. Data on the use of this procedure are limited. The purpose of this study was to identify the incidence, causes, surgical techniques, and outcomes of arthrodesis after failed knee arthroplasty...... in a nationwide population. METHODS: Data were extracted from the Danish Civil Registration System, the Danish National Patient Register, and the Danish Knee Arthroplasty Register. A total of 92,785 primary knee arthroplasties performed in Denmark from 1997 to 2013 were identified by linking the data using....... Differences in cumulative incidence were compared with the Gray test. RESULTS: A total of 164 of the 165 arthrodeses were performed for causes related to failed knee arthroplasty. The 15-year cumulative incidence of arthrodesis was 0.26% (95% confidence interval, 0.21% to 0.31%). The 5-year cumulative...

[Knee disarticulation and through-knee amputation].

Science.gov (United States)

Baumgartner, R

2011-10-01

A knee disarticulation or a through-knee stump is superior compared to a transfemoral stump. The thigh muscles are all preserved, and the muscle balance remains undisturbed. The range of motion of the hip joint is not limited. The bulbous shape of the stump allows full weight bearing at the stump end and can easily be fitted with a prosthesis. An amputee with a bilateral knee disarticulation is able to walk "barefoot". A more distal amputation level, e.g., an ultra-short transtibial amputation, is not possible. Important alternative to transfemoral amputations. Possible for any etiology except for Buerger-Winiwarter's disease. New indications are infected and loosened total knee replacements. Preservation of the knee joint is possible. Knee disarticulation is a very atraumatic procedure, compared to transfemoral amputations. Neither bones nor muscles have to be severed, just skin, ligaments, vessels, and nerves. Even the meniscal cartilages may be left in place to act as axial shock absorbers. The cartilage of the femur is not resected, but only bevelled in case of osteoarthritis. There are no tendon attachments or myoplastic procedures necessary. The patella remains in place and is held in position only by the retinacula. Skin closure must be performed without the slightest tension, and if possible not in the weight-bearing area. Transcondylar amputations across the femoral condyles only are indicated when there are not sufficient soft tissues for wound closure of a knee disarticulation. Alternatives as the techniques of Gritti, Klaes, and Eigler, the shortening of the femur and the Sauerbruch's rotation plasty [14] are presented and discussed. The risk of decubital ulcers is rather high. Correct bandaging of the stump is, therefore, particularly important. Prosthetic fitting is possible 3-6 weeks after surgery. The type of prosthesis depends on the amputee's activity level. The superior performance of amputees with knee disarticulations in sports prove the

Knee mechanics during planned and unplanned sidestepping: a systematic review and meta-analysis.

Science.gov (United States)

Brown, Scott R; Brughelli, Matt; Hume, Patria A

2014-11-01

Knee joint mechanics during sidestepping are associated with anterior cruciate ligament injury. Unplanned sidestepping more closely emulates game scenarios when compared with planned sidestepping by limiting decision time, increasing knee loading and challenging the integrity of soft-tissue structures in the knee. It is important to quantify the loads that may challenge the integrity of the knee during planned and unplanned sidestepping. Our objective was to review literature on knee mechanics during planned and unplanned phases of sidestepping. PubMed, CINAHL, MEDLINE (EBSCO), SPORTDiscus and Web of Science were searched using the terms knee mechanics OR knee kine*, AND plan*, unplan*, anticipat*, unanticipat*, side*, cut* or chang*. A systematic approach was used to evaluate 4,629 records. Records were excluded when not available in English, only available in abstract of conference proceedings, not involving a change-of-direction sidestep, not comparing planned and unplanned or maintaining a running velocity greater than 2 m s(−1). Included studies were evaluated independently by two authors using a custom-designed methodological quality assessment derived from the Physiotherapy Evidence Database (PEDro) scale and then confirmed by a third author. Only six studies met the inclusion criteria and were retained for meta-analysis. Magnitude-based inferences were used to assess the standardised effect of the differences between planned and unplanned sidestepping. Knee angles and knee moments were extracted and reported for flexion/extension, abduction/adduction and internal/external rotation for initial contact, weight acceptance, peak push-off and final push-off phases of sidestepping. For kinematic variables, unplanned sidestepping produced a wide range of small to large increases in knee extension angles, small and moderate increases in knee abduction angles and a small increase in internal rotation angle relative to planned sidestepping during the sidestepping

The effects of a supportive knee brace on leg performance in healthy subjects.

Science.gov (United States)

Veldhuizen, J W; Koene, F M; Oostvogel, H J; von Thiel, T P; Verstappen, F T

1991-12-01

Eight healthy volunteers were fitted with a supportive knee brace (Push Brace 'Heavy') to one knee for a duration of four weeks wherein they were tested before, during and after the application to establish the effect of bracing on performance. The tests consisted of isokinetic strength measurement of knee flexion and extension, 60 meter dash, vertical jump height and a progressive horizontal treadmill test until exhaustion (Vmax) with determination of oxygen uptake, heart rate and plasma lactate concentration. Wearing the brace for one day, the performance indicators showed a decline compared with the test before application (base values). Sprint time was 4% longer (p less than 0.01) and Vmax 6% slower (p less than 0.01). Peak torque of knee flexion at 60 and 240 deg.sec-1 was 6% (p less than 0.05) respectively 9% (p less than 0.05) less. Peak extension torque at 60 deg.sec-1 was 9% less (p less than 0.05). While wearing the brace for four weeks, the test performances were practically identical to their base values. After removal of the brace, all test parameters were statistically similar to the base values. Heart rate at submaximal exercise levels was even lower (p less than 0.05). In conclusion, performance in sports with test-like exercise patterns is not affected by the brace tested. Bracing does not "weaken the knee" as it is widely believed in sports practice.

Does knee awareness differ between different knee arthroplasty prostheses?

DEFF Research Database (Denmark)

Thomsen, Morten G; Latifi, Roshan; Kallemose, Thomas

2016-01-01

BACKGROUND: Low knee awareness after Total Knee Arthroplasty (TKA) has become the ultimate goal in trying to achieve a natural feeling knee that meet patient expectations. To accommodate this manufacturers of TKAs have developed new prosthetic designs that potentially could give patients a more...... natural feeling knee during activities. The purpose af this study was to compare the Forgotten Joint Score (FJS) and Oxford Knee Score (OKS) of patients treated with a previous generation standard Cruciate Retaining (CR) TKA to the scores obtained by patients treated with a newer generation CR TKA...

Sex-Based Differences in Knee Kinetics With Anterior Cruciate Ligament Strain on Cadaveric Impact Simulations

Science.gov (United States)

Schilaty, Nathan D.; Bates, Nathaniel A.; Nagelli, Christopher; Krych, Aaron J.; Hewett, Timothy E.

2018-01-01

Background: Females are at an increased risk of sustaining noncontact knee ligament injuries as compared with their male counterparts. The kinetics that load the anterior cruciate ligament (ACL) are still under dispute in the literature. Purpose/Hypothesis: The purpose of this study was to determine whether there are differences in knee kinetics between the sexes that lead to greater ACL strain in females when similar external loads are applied during a simulated drop vertical jump landing task. It was hypothesized that female limbs would demonstrate significant differences in knee abduction moment that predispose females to ACL injury when compared with males. Study Design: Controlled laboratory study. Methods: Motion analysis data of 67 athletes who performed a drop vertical jump were collected. The kinematic and kinetic data were used to categorize tertiles of relative risk, and these values were input into a cadaveric impact simulator to assess ligamentous loads during the simulated landing task. Uni- and multiaxial load cells and differential variable reluctance transducer strain sensors were utilized to collect kinetic data and maximum ACL strain for analysis. Conditions of external loads applied to the cadaveric limbs were systematically varied and randomized. Data were analyzed with 2-way repeated-measures analysis of variance and the Fisher exact test. Results: Five kinetic parameters were evaluated. Of the 5 kinetic variables, only knee abduction moment (KAM) demonstrated significant differences in females as compared with males (F 1,136 = 4.398, P = .038). When normalized to height and weight, this difference between males and females increased in significance (F 1,136 = 7.155, P = .008). Compared with males, females exhibited a 10.3-N·m increased knee abduction torque at 66 milliseconds postimpact and a 22.3-N·m increased abduction torque at 100 milliseconds postimpact. For loading condition, the condition of “maximum ACL strain” demonstrated a

21 CFR 888.3570 - Knee joint femoral (hemi-knee) metallic uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint femoral (hemi-knee) metallic uncemented... HUMAN SERVICES (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Prosthetic Devices § 888.3570 Knee joint femoral (hemi-knee) metallic uncemented prosthesis. (a) Identification. A knee joint femoral (hemi-knee...

Effects of physiotherapy treatment on knee osteoarthritis gait data using principal component analysis.

Science.gov (United States)

Gaudreault, Nathaly; Mezghani, Neila; Turcot, Katia; Hagemeister, Nicola; Boivin, Karine; de Guise, Jacques A

2011-03-01

Interpreting gait data is challenging due to intersubject variability observed in the gait pattern of both normal and pathological populations. The objective of this study was to investigate the impact of using principal component analysis for grouping knee osteoarthritis (OA) patients' gait data in more homogeneous groups when studying the effect of a physiotherapy treatment. Three-dimensional (3D) knee kinematic and kinetic data were recorded during the gait of 29 participants diagnosed with knee OA before and after they received 12 weeks of physiotherapy treatment. Principal component analysis was applied to extract groups of knee flexion/extension, adduction/abduction and internal/external rotation angle and moment data. The treatment's effect on parameters of interest was assessed using paired t-tests performed before and after grouping the knee kinematic data. Increased quadriceps and hamstring strength was observed following treatment (Pphysiotherapy on gait mechanics of knee osteoarthritis patients may be masked or underestimated if kinematic data are not separated into more homogeneous groups when performing pre- and post-treatment comparisons. Copyright © 2010 Elsevier Ltd. All rights reserved.

Imaging of the knee joint with emphasis on magnetic resonance imaging

Energy Technology Data Exchange (ETDEWEB)

Reiser, M.F. [Radiologische Universitaetsklinik, Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany); Vahlensieck, M. [Radiologische Universitaetsklinik, Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany); Schueller, H. [Radiologische Universitaetsklinik, Rheinische Friedrich-Wilhelms-Univ., Bonn (Germany)

1992-04-01

The knee joint is frequently affected by trauma as well as degenerative and inflammatory disorders, involving the internal structures (i.e. ligaments, menisci, cartilage, synovial membrane) and the adjacent bones. Plain radiographs represent an indispensable basis for diagnosis. For further analysis magnetic resonance imaging (MRI) has become the method of choice, and has widely replaced computed tomography, arthrography and stress examinations. Extensive experience has been accumulated in MRI of the knee joint in recent years. In addition, advances in MRI technology have had a major impact on diagnostic accuracy. In this paper, diagnosis of various lesions of the knee joint, such as meniscal and ligamental injuries, aseptic necrosis, lesions of the hyaline cartilage, occult fractures and inflammatory lesions will be discussed. (orig.)

In vivo kinematics of a robot-assisted uni- and multi-compartmental knee arthroplasty.

Science.gov (United States)

Watanabe, Toshifumi; Abbasi, Ali Z; Conditt, Michael A; Christopher, Jennifer; Kreuzer, Stefan; Otto, Jason K; Banks, Scott A

2014-07-01

There is great interest in providing reliable and durable treatments for one- and two-compartment arthritic degeneration of the cruciate-ligament intact knee. One approach is to resurface only the diseased compartments with discrete unicompartmental components, retaining the undamaged compartment(s). However, placing multiple small implants into the knee presents a greater surgical challenge than total knee arthroplasty, so it is not certain that the natural knee mechanics can be maintained or restored. The goal of this study was to determine whether near-normal knee kinematics can be obtained with a robot-assisted multi-compartmental knee arthroplasty. Thirteen patients with 15 multi-compartmental knee arthroplasties using haptic robotic-assisted bone preparation were involved in this study. Nine subjects received a medial unicompartmental knee arthroplasty (UKA), three subjects received a medial UKA and patellofemoral (PF) arthroplasty, and three subjects received medial and lateral bi-unicondylar arthroplasty. Knee motions were recorded using video-fluoroscopy an average of 13 months (6-29 months) after surgery during stair and kneeling activities. The three-dimensional position and orientation of the implant components were determined using model-image registration techniques. Knee kinematics during maximum flexion kneeling showed femoral external rotation and posterior lateral condylar translation. All knees showed femoral external rotation and posterior condylar translation with flexion during the step activity. Knees with medial UKA and PF arthroplasty showed the most femoral external rotation and posterior translation, and knees with bicondylar UKA showed the least. Knees with accurately placed uni- or bi-compartmental arthroplasty exhibited stable knee kinematics consistent with intact and functioning cruciate ligaments. The patterns of tibiofemoral motion were more similar to natural knees than commonly has been observed in knees with total knee

CURBSIDE CONSULTATION IN KNEE ARTHROPLASTY: 49 CLINICAL QUESTIONS

Directory of Open Access Journals (Sweden)

Craig J. Della Vale

2008-12-01

Full Text Available A user- friendly reference for decision making in complicated cases of knee arthroplasty desingned in a question and answers format composed of articles containing current concepts and preferences of experts in total knee replacement surgery, enhanced by several images, diagrams and references and written in the form of a casual advice by Craig J. Della Vale, MD. and his collaborators. PURPOSE By this practical reference of knee arthroplasty, the editor and the contributors have aimed providing straightforward and brief answers, evidence-based advices, their preference and opinions containing current concepts for unanswered questions about complicated cases in total knee replacement surgery which are often controversial and not addressed clearly in traditional knee arthroplasty references. FEATURES There are 49 subjects each written by a different expert designed in 4 sections in a question and answers format including several images and diagrams and also essential references at the end of each article. In the first section preoperative questions is subjected including indications, unicompartmental osteoarthritis of the knee, patient with vascular problems, donating blood, bilateral arthroplasty, patellar resurfacing, range of motion, bearing surface, contraindications, teaching class for patients prior surgery. The second section is about intraoperative questions including skin incision, patella femoral maltracking, femoral component rotation, tibial component rotation, lateral release, femoral component sizing, flexion instability, varus deformity, and valgus deformity, tightness in extension, iatrogenic MCL injury, antibiotic-loaded cement, and perioperative pain. The third section subjects postoperative questions including wound drainage, preventing tromboembolic events, vascular complications, foot drop, manipulation under anesthesia, patella fractures, supracondylar femur fractures, acute extensor mechanism disruptions. In the fourth

The Validity of a New Low-Dose Stereoradiography System to Perform 2D and 3D Knee Prosthetic Alignment Measurements.

Science.gov (United States)

Meijer, Marrigje F; Velleman, Ton; Boerboom, Alexander L; Bulstra, Sjoerd K; Otten, Egbert; Stevens, Martin; Reininga, Inge H F

2016-01-01

The EOS stereoradiography system has shown to provide reliable varus/valgus (VV) measurements of the lower limb in 2D (VV2D) and 3D (VV3D) after total knee arthroplasty (TKA). Validity of these measurements has not been investigated yet, therefore the purpose of this study was to determine validity of EOS VV2D and VV3D. EOS images were made of a lower limb phantom containing a knee prosthesis, while varying VV angle from 15° varus to 15° valgus and flexion angle from 0° to 20°, and changing rotation from 20° internal to 20° external rotation. Differences between the actual VV position of the lower limb phantom and its position as measured on EOS 2D and 3D images were investigated. Rotation, flexion or VV angle alone had no major impact on VV2D or VV3D. Combination of VV angle and rotation with full extension did not show major differences in VV2D measurements either. Combination of flexion and rotation with a neutral VV angle showed variation of up to 7.4° for VV2D; maximum variation for VV3D was only 1.5°. A combination of the three variables showed an even greater distortion of VV2D, while VV3D stayed relatively constant. Maximum measurement difference between preset VV angle and VV2D was 9.8°, while the difference with VV3D was only 1.9°. The largest differences between the preset VV angle and VV2D were found when installing the leg in extreme angles, for example 15° valgus, 20° flexion and 20° internal rotation. After TKA, EOS VV3D were more valid than VV2D, indicating that 3D measurements compensate for malpositioning during acquisition. Caution is warranted when measuring VV angle on a conventional radiograph of a knee with a flexion contracture, varus or valgus angle and/or rotation of the knee joint during acquisition.

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

DEFF Research Database (Denmark)

Clausen, Mikkel Bek; Tang, L; Zebis, M K

2016-01-01

with low KOOS subscale scores (Sport/Recreational (RR: 2.2) and Quality of Life (RR: 3.0) (P time-loss knee...... 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 (... as independent variables in the risk factor analyses. The study showed that self-reported previous knee injury significantly increased the risk of time-loss knee injury [relative risk (RR): 3.65, 95% confidence (CI) 1.73-7.68; P time-loss knee injury was also significantly increased in players...

Magnification bone scan of knees for knee pain evaluation

International Nuclear Information System (INIS)

Lee, Myoung Hoon; Park, Chan H.; Yoon, Seok Nam; Hwang, Kyung Hoon

2001-01-01

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

Association of knee confidence with pain, knee instability, muscle strength, and dynamic varus-valgus joint motion in knee osteoarthritis.

Science.gov (United States)

Skou, Søren T; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Bennell, Kim L

2014-05-01

To investigate associations between self-reported knee confidence and pain, self-reported knee instability, muscle strength, and dynamic varus-valgus joint motion during walking. We performed a cross-sectional analysis of baseline data from 100 participants with symptomatic and radiographic medial tibiofemoral compartment osteoarthritis (OA) and varus malalignment recruited for a randomized controlled trial. The extent of knee confidence, assessed using a 5-point Likert scale item from the Knee Injury and Osteoarthritis Outcome Score, was set as the dependent variable in univariable and multivariable ordinal regression, with pain during walking, self-reported knee instability, quadriceps strength, and dynamic varus-valgus joint motion during walking as independent variables. One percent of the participants were not troubled with lack of knee confidence, 17% were mildly troubled, 50% were moderately troubled, 26% were severely troubled, and 6% were extremely troubled. Significant associations were found between worse knee confidence and higher pain intensity, worse self-reported knee instability, lower quadriceps strength, and greater dynamic varus-valgus joint motion. The multivariable model consisting of the same variables significantly accounted for 24% of the variance in knee confidence (P knee confidence is associated with higher pain, worse self-reported knee instability, lower quadriceps muscle strength, and greater dynamic varus-valgus joint motion during walking. Since previous research has shown that worse knee confidence is predictive of functional decline in knee OA, addressing lack of knee confidence by treating these modifiable impairments could represent a new therapeutic target. Copyright © 2014 by the American College of Rheumatology.

Skinfold thickness affects the isometric knee extension torque evoked by Neuromuscular Electrical Stimulation.

Science.gov (United States)

Medeiros, Flávia V A; Vieira, Amilton; Carregaro, Rodrigo L; Bottaro, Martim; Maffiuletti, Nicola A; Durigan, João L Q

2015-01-01

Subcutaneous adipose tissue may influence the transmission of electrical stimuli through to the skin, thus affecting both evoked torque and comfort perception associated with neuromuscular electrical stimulation (NMES). This could seriously affect the effectiveness of NMES for either rehabilitation or sports purposes. To investigate the effects of skinfold thickness (SFT) on maximal NMES current intensity, NMES-evoked torque, and NMES-induced discomfort. First, we compared NMES current intensity, NMES-induced discomfort, and NMES-evoked torque between two subgroups of subjects with thicker (n=10; 20.7 mm) vs. thinner (n=10; 29.4 mm) SFT. Second, we correlated SFT to NMES current intensity, NMES-induced discomfort, and NMES-evoked knee extension torque in 20 healthy women. The NMES-evoked torque was normalized to the maximal voluntary contraction (MVC) torque. The discomfort induced by NMES was assessed with a visual analog scale (VAS). NMES-evoked torque was 27.5% lower in subjects with thicker SFT (p=0.01) while maximal current intensity was 24.2% lower in subjects with thinner SFT (p=0.01). A positive correlation was found between current intensity and SFT (r=0.540, p=0.017). A negative correlation was found between NMES-evoked torque and SFT (r=-0.563, p=0.012). No significant correlation was observed between discomfort scores and SFT (rs=0.15, p=0.53). These results suggest that the amount of subcutaneous adipose tissue (as reflected by skinfold thickness) affected NMES current intensity and NMES-evoked torque, but had no effect on discomfort perception. Our findings may help physical therapists to better understand the impact of SFT on NMES and to design more rational stimulation strategies.

Statistical mapping of the effect of knee extension on thigh muscle viscoelastic properties using magnetic resonance elastography

International Nuclear Information System (INIS)

Barnhill, Eric; Kennedy, Paul; Van Beek, Edwin J R; Roberts, Neil; Hammer, Steven; Brown, Colin

2013-01-01

Skeletal muscle viscoelastic properties reflect muscle microstructure and neuromuscular activation. Elastographic methods, including magnetic resonance elastography, have been used to characterize muscle viscoelastic properties in terms of region of interest (ROI) measurements. The present study extended this approach to create thresholded pixel-by-pixel maps of viscoelastic properties of skeletal muscle during rest and knee extension in eleven subjects. ROI measurements were taken for individual quadricep muscles and the quadriceps region as a whole, and the viscoelastic parameter map pixels were statistically tested at positive false discovery rate q ⩽ 0.25. ROI measurements showed significant (p ⩽ 0.05) increase in storage modulus (G′) and loss modulus (G″), with G″ increasing more than G′, in agreement with previous findings. The q-value maps further identified the vastus intermedius as the primary driver of this change, with greater G″/G′ increase than surrounding regions. Additionally, a cluster of significant decrease in G″/G′ was found in the region of vastus lateralis below the fulcrum point of the lift. Viscoelastic parameter mapping of contracted muscle allows new insight into the relationship between physiology, neuromuscular activation, and human performance. (paper)

The Relationship between Isokinetic Relative Torque of Hip, Knee and Ankle Joints and the Height of Guide Leg Jump in Young Men

Directory of Open Access Journals (Sweden)

Saeed Nikoukheslat

2016-06-01

Full Text Available Objective: The aim of this study was to investigate the relationship between isokinetic relative torques of hip, knee and ankle joints and the height of guide leg jump in young men. Methods: 27 college male athletes with mean age of 25±3.5 years, height 178.5±7.8 cm and weight of 75.7±10.7 kg voluntarily participated in this study. Isokinetic torque of hip, knee and ankle joints and the height of vertical jump were measured using BIODEX SYSTEM PRO 4 and digital vertical jumping tester systems respectively. Pearson correlation test at p<0.05 was used for statistical analysis. Results: Results showed that there were significant correlations between height of jump and hip joint flexion (p= 0.047 & r= 0.39 and extension (p= 0.003 & r= 0.55 torques of guide leg, hip joint extension torque of support leg (p= 0.020 & r=0.45 and knee joint flexion (p= 0.019 & r=0.45 and extension torques of support leg (p=0.006 & r=0.52. Conclusion: The results of this study show that flexion and extension torques of hip joint in guide leg and knee joint in support leg and also extension torque of hip joint in support leg have main effect on height of guide leg jump. Thus, in designing a specific training program for athletes in whom the nature of jump in their sports is guide leg jump, particular attention should be given to hip and knee joints strength.

Knee point search using cascading top-k sorting with minimized time complexity.

Science.gov (United States)

Wang, Zheng; Tseng, Shian-Shyong

2013-01-01

Anomaly detection systems and many other applications are frequently confronted with the problem of finding the largest knee point in the sorted curve for a set of unsorted points. This paper proposes an efficient knee point search algorithm with minimized time complexity using the cascading top-k sorting when a priori probability distribution of the knee point is known. First, a top-k sort algorithm is proposed based on a quicksort variation. We divide the knee point search problem into multiple steps. And in each step an optimization problem of the selection number k is solved, where the objective function is defined as the expected time cost. Because the expected time cost in one step is dependent on that of the afterwards steps, we simplify the optimization problem by minimizing the maximum expected time cost. The posterior probability of the largest knee point distribution and the other parameters are updated before solving the optimization problem in each step. An example of source detection of DNS DoS flooding attacks is provided to illustrate the applications of the proposed algorithm.

The effects of age and step length on joint kinematics and kinetics of large out-and-back steps.

Science.gov (United States)

Schulz, Brian W; Ashton-Miller, James A; Alexander, Neil B

2008-06-01

Maximum step length (MSL) is a clinical test that has been shown to correlate with age, various measures of fall risk, and knee and hip joint extension speed, strength, and power capacities, but little is known about the kinematics and kinetics of the large out-and-back step utilized. Body motions and ground reaction forces were recorded for 11 unimpaired younger and 10 older women while attaining maximum step length. Joint kinematics and kinetics were calculated using inverse dynamics. The effects of age group and step length on the biomechanics of these large out-and-back steps were determined. Maximum step length was 40% greater in the younger than in the older women (P<0.0001). Peak knee and hip, but not ankle, angle, velocity, moment, and power were generally greater for younger women and longer steps. After controlling for age group, step length generally explained significant additional variance in hip and torso kinematics and kinetics (incremental R2=0.09-0.37). The young reached their peak knee extension moment immediately after landing of the step out, while the old reached their peak knee extension moment just before the return step liftoff (P=0.03). Maximum step length is strongly associated with hip kinematics and kinetics. Delays in peak knee extension moment that appear to be unrelated to step length, may indicate a reduced ability of older women to rapidly apply force to the ground with the stepping leg and thus arrest the momentum of a fall.

Posterior-anterior weight-bearing radiograph in 15 knee flexion in medial osteoarthritis

International Nuclear Information System (INIS)

Yamanaka, Norio; Takahashi, Toshiaki; Yamamoto, Hiroshi; Ichikawa, Norikazu

2003-01-01

To evaluate the degree of knee flexion at which: (1) degenerative joint space narrowing is best seen, (2) the tibial plateau is best visualized and (3) the tibiofemoral angle is most correct, in order to assess the degree of flexion in the anteroposterior radiographic view that is most useful for assessing medial compartment osteoarthritis (OA) of the knee.Design and patients. We compared the conventional extended view of the knee and views at 15 , 30 , and 45 of flexion with respect to joint space narrowing, alignment of the medial tibial plateau (MTP), and tibiofemoral angles in 113 knees of 95 patients with medial osteoarthritis of the knee (22 men, 73 women; mean age 67 years).Results. At the midpoint and the narrowest point of the medial compartment, joint space narrowing values at 15 , 30 , and 45 of flexion of the knee were smaller than that of the conventional extended view. Superimposition of the margins of the tibial plateau was satisfactory in 12% of patients in the conventional extended view, in 36% at 15 of flexion, in 20% at 30 of flexion, and in 19% at 45 of flexion of the knee. When the knee was at 15 of flexion there was a smaller difference in the tibiofemoral angle, in comparison with the knee extended, than was the case at 30 and 45 of flexion in patients with medial OA.Conclusion. A posteroanterior view with 15 of flexion of the knee was able to detect joint space narrowing accurately, to achieve good alignment of the MTP in the medial compartment, and to reduce the difference in tibiofemoral angle compared with a view of the knee in conventional extension, and may be an alternative view in cases of medial OA of the knee. (orig.)

Isokinetic and isometric strength in osteoarthrosis of the knee. A comparative study with healthy women.

Science.gov (United States)

Tan, J; Balci, N; Sepici, V; Gener, F A

1995-01-01

Dynamic stability of the knee joint depends on the appropriate strength ratio of quadriceps and hamstring muscles. The purpose of this investigation was to determine the maximum peak torque (MPT) and MPT ratios of hamstrings to quadriceps (H/Q) muscles in patients with knee osteoarthritis (OA). Two groups of patients were included in the study. The first group consisted of 30 patients (Group A) with the clinical and radiologic findings of knee OA. The second group consisted of 30 patients (Group B) exhibiting knee joint pain without roentgenologic findings of knee OA. The findings of two patient groups were compared with each other and also with 30 healthy subjects (Group C). Isokinetic (at 60 degrees/s and at 180 degrees/s) and isometric (at 30 degrees and at 60 degrees of knee flexion) tests were performed by the rate-limiting isokinetic dynamometer system. Isokinetic and isometric MPT loss of knee flexors and extensors was found in both patient groups with respect to controls, but MPT ratios of H/Q muscles did not show a statistically significant difference compared with the control group. This may be related to the equal strength loss of knee flexors and knee extensors in patients with knee OA. It is concluded that strengthening exercises of hamstring muscles is as important as quadriceps strengthening in rehabilitation of knee OA.

Relationships of Muscle Function and Subjective Knee Function in Patients After ACL Reconstruction.

Science.gov (United States)

Bodkin, Stephan; Goetschius, John; Hertel, Jay; Hart, Joe

2017-07-01

After anterior cruciate ligament reconstruction (ACLR), relationships between objective measures of muscle function and patient-reported outcomes may change over time. Examining these measures at different time frames after surgery may help develop individualized approaches to improve post-ALCR analysis. To examine the associations between subjective knee function and lower-extremity muscle function in individual patients at various time points after ACLR. Descriptive laboratory study. Fifty-one participants who underwent primary, unilateral ACLR (15 males, 36 females; mean age, 22.9 ± 4.5 years; mean height, 172.4 ± 10.1 cm; mean weight, 68.7 ± 13.1 kg) were separated into 3 groups depending on time since surgery (early, 5 years). Subjective knee function was quantified using the International Knee Documentation Committee (IKDC) subjective knee form and the Knee injury and Osteoarthritis Outcome Score (KOOS). Isometric knee extension and flexion strength were collected at 90 deg/s. Single-leg hop performance was measured using the single hop, triple hop, cross-over hop, and 6-m timed hop. Coefficient correlations were calculated between subjective knee function and objective measures of muscle function for each group. The early group demonstrated moderate correlations between the KOOS and unilateral measures of flexion peak torque ( r = 0.514, P = .035) and flexion power ( r = 0.54, P = .027). The middle group demonstrated the strongest correlations between the KOOS and symmetry measures of the single hop ( r = 0.69, P = .002) and extension work ( r = 0.71, P = .002) as well as unilateral measures of the triple hop ( r = 0.52, P = .034) and extension work ( r = 0.66, P = .004). The late group demonstrated strong correlations between the 6-m timed hop symmetry and the IKDC ( r = 0.716, P = .001) and KOOS ( r = 0.71, P = .001). Patients with a post-ACLR status of less than 2 years exhibited stronger relationships with unilateral strength measures to subjective

Influence of Total Knee Arthroplasty on Gait Mechanics of the Replaced and Non-Replaced Limb During Stair Negotiation.

Science.gov (United States)

Standifird, Tyler W; Saxton, Arnold M; Coe, Dawn P; Cates, Harold E; Reinbolt, Jeffrey A; Zhang, Songning

2016-01-01

This study compared biomechanics during stair ascent in replaced and non-replaced limbs of total knee arthroplasty (TKA) patients with control limbs of healthy participants. Thirteen TKA patients and fifteen controls performed stair ascent. Replaced and non-replaced knees of TKA patients were less flexed at contact compared to controls. The loading response peak knee extension moment was greater in control and non-replaced knees compared with replaced. The push-off peak knee abduction moment was elevated in replaced limbs compared to controls. Loading and push-off peak hip abduction moments were greater in replaced limbs compared to controls. The push-off peak hip abduction moment was greater in non-replaced limbs compared to controls. Future rehabilitation protocols should consider the replaced knee and also the non-replaced knee and surrounding joints. Copyright © 2016 Elsevier Inc. All rights reserved.

Requirements for the retrofitting an extension of the maximum voltage power grid from the point of view of environmental protection and cultivated landscape work

International Nuclear Information System (INIS)

2013-01-01

The project on the requirements for the retrofitting an extension of the maximum voltage power grid from the point of view of environmental protection and cultivated landscape work includes contributions on the following topics: the development of the European transmission grid, the grid extension law, restrictions for the power grid and their infrastructure, requirements for the regulations concerning the realization of the transnational grid extension, inclusion of the public - public acceptance - communication, requirements concerning the environmental compensation law, overhead line - underground cable - health hazards, ecological effects of overhead lines and underground cables, infrastructural projects, power supply in the future, structural relief by photovoltaics.

Total replace in the knee with deformity in the valgus

International Nuclear Information System (INIS)

Lara Cortassio, Gilberto; Pineros Ramirez, Daniel Francisco

2006-01-01

The total knee arthroplasty with valgus deformity is a technically demanding surgery. The bone deformities and the soft tissues make difficult to balance the soft tissues, the mechanic axis restoration and the prostheses placement. We present the results of a retrospective study, observational, descriptive type series of cases of 40 patients (42 prostheses), operated on with valgus deformity of more than 10 grades, using the I. White side technique to balance the soft tissue, with and average following up of 4.5 years. Based on the knee society scale (KSS) we found satisfactory results in more than 92% of the cases (39 prostheses). The complications were: total lost of the knee extension in 2 patients and i femoropatellar misalignment. We recommend practicing a sequential liberation of the lateral soft tissue to obtain a good clinical result and prostheses longevity

Bouncy knee in a semi-automatic knee lock prosthesis.

Science.gov (United States)

Fisher, L D; Lord, M

1986-04-01

The Bouncy Knee concept has previously proved of value when fitted to stabilised knee units of active amputees. The stance phase flex-extend action afforded by a Bouncy Knee increased the symmetry of gait and also gave better tolerance to slopes and uneven ground. A bouncy function has now been incorporated into a knee of the semi-automatic knee lock design in a pilot laboratory trial involving six patients. These less active patients did not show consistent changes in symmetry of gait, but demonstrated an improved ability to walk on slopes and increased their walking range. Subjective response was positive, as noted in the previous trials.

Muscle Power Is an Independent Determinant of Pain and Quality of Life in Knee Osteoarthritis.

Science.gov (United States)

Reid, Kieran F; Price, Lori Lyn; Harvey, William F; Driban, Jeffrey B; Hau, Cynthia; Fielding, Roger A; Wang, Chenchen

2015-12-01

This study examined the relationships between leg muscle strength, power, and perceived disease severity in subjects with knee osteoarthritis (OA) in order to determine whether dynamic leg extensor muscle power would be associated with pain and quality of life in knee OA. Baseline data on 190 subjects with knee OA (mean ± SD age 60.2 ± 10.4 years, body mass index 32.7 ± 7.2 kg/m(2) ) were obtained from a randomized controlled trial. Knee pain was measured using the Western Ontario and McMaster Universities Osteoarthritis Index, and health-related quality of life was assessed using the Short Form 36 (SF-36). One-repetition maximum (1RM) strength was assessed using the bilateral leg press, and peak muscle power was measured during 5 maximum voluntary velocity repetitions at 40% and 70% of 1RM. In univariate analysis, greater muscle power was significantly associated with pain (r = -0.17, P power was a significant independent predictor of pain (P ≤ 0.05) and PCS scores (P ≤ 0.04). However, muscle strength was not an independent determinant of pain or quality of life (P ≥ 0.06). Muscle power is an independent determinant of pain and quality of life in knee OA. Compared to strength, muscle power may be a more clinically important measure of muscle function within this population. New trials to systematically examine the impact of muscle power training interventions on disease severity in knee OA are particularly warranted. © 2015, American College of Rheumatology.

Knee pain (image)

Science.gov (United States)

The location of knee pain can help identify the problem. Pain on the front of the knee can be due to bursitis, arthritis, or ... synovial fluid) that forms behind the knee. Overall knee pain can be due to bursitis, arthritis, tears in ...

Effect of Knee Joint Angle and Contraction Intensity on Hamstrings Coactivation.

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Wu, Rui; Delahunt, Eamonn; Ditroilo, Massimiliano; Lowery, Madeleine M; DE Vito, Giuseppe

2017-08-01

This study investigated the effect of knee joint angle and contraction intensity on the coactivation of the hamstring muscles (when acting as antagonists to the quadriceps) in young and older individuals of both sexes. A total of 25 young (24 ± 2.6 yr) and 26 older (70 ± 2.5 yr) healthy men and women participated. Maximal voluntary isometric contraction of the knee extensors and flexors was assessed at two knee joint angles (90° and 60°, 0° = full extension). At each angle, participants performed submaximal contractions of the knee extensors (20%, 50%, and 80% maximal voluntary isometric contraction), whereas surface EMG was simultaneously acquired from the vastus lateralis and biceps femoris muscles to assess the level (EMG root-mean-square) of agonist activation and antagonist coactivation. Subcutaneous adipose tissue in the areas corresponding to surface EMG electrode placements was measured via ultrasonography. The contractions performed at 90° knee flexion demonstrated higher levels of antagonist coactivation (all P < 0.01) and agonist activation (all P < 0.01) as a function of contraction intensity compared with the 60° knee flexion. Furthermore, after controlling for subcutaneous adipose tissue, older participants exhibited a higher level of antagonist coactivation at 60° knee flexion compared with young participants (P < 0.05). The results of the present study suggest that 1) the antagonist coactivation is dependent on knee joint angle and contraction intensity and 2) subcutaneous adipose tissue may affect the measured coactivation level likely because of a cross-talk effect. Antagonist coactivation may play a protective role in stabilizing the knee joint and maintaining constant motor output.

Impact of knee support and shape of tabletop on rectum and prostate position

International Nuclear Information System (INIS)

Steenbakkers, Roel; Duppen, Joop C.; Betgen, Anja; Lotz, Heidi; Remeijer, Peter; Fitton, Isabelle; Nowak, Peter; Herk, Marcel van; Rasch, Coen

2004-01-01

Purpose: To evaluate the impact of different tabletops with or without a knee support on the position of the rectum, prostate, and bulb of the penis; and to evaluate the effect of these patient-positioning devices on treatment planning. Methods and materials: For 10 male volunteers, five MRI scans were made in four different positions: on a flat tabletop with knee support, on a flat tabletop without knee support, on a rounded tabletop with knee support, and on a rounded tabletop without knee support. The fifth scan was in the same position as the first. With image registration, the position differences of the rectum, prostate, and bulb of the penis were measured at several points in a sagittal plane through the central axis of the prostate. A planning target volume was generated from the delineated prostates with a margin of 10 mm in three dimensions. A three-field treatment plan with a prescribed dose of 78 Gy to the International Commission on Radiation Units and Measurements point was automatically generated from each planning target volume. Dose-volume histograms were calculated for all rectal walls. Results: The shape of the tabletop did not affect the rectum and prostate position. Addition of a knee support shifted the anterior and posterior rectal walls dorsally. For the anterior rectal wall, the maximum dorsal shift was 9.9 mm (standard error of the mean [SEM] 1.7 mm) at the top of the prostate. For the posterior rectal wall, the maximum dorsal shift was 10.2 mm (SEM 1.5 mm) at the middle of the prostate. Therefore, the rectal filling was pushed caudally when a knee support was added. The knee support caused a rotation of the prostate around the left-right axis at the apex (i.e., a dorsal rotation) by 5.6 deg (SEM 0.8 deg ) and shifts in the caudal and dorsal directions of 2.6 mm (SEM 0.4 cm) and 1.4 mm (SEM 0.6 mm), respectively. The position of the bulb of the penis was not influenced by the use of a knee support or rounded tabletop. The volume of the

21 CFR 888.3590 - Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint tibial (hemi-knee) metallic resurfacing... Knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint tibial (hemi-knee) metallic resurfacing uncemented prosthesis is a device intended to be implanted...

21 CFR 888.3580 - Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Knee joint patellar (hemi-knee) metallic... § 888.3580 Knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis. (a) Identification. A knee joint patellar (hemi-knee) metallic resurfacing uncemented prosthesis is a device made of...

Optimum conductive fabric sensor sites for evaluating the status of knee joint movements using bio-impedance

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Kim Jinkwon

2011-06-01

Full Text Available Abstract Background There have been many studies that utilize the bio-impedance measurement method to analyze the movements of the upper and lower limbs. A fixed electrical current flows into the limbs through four standard disposable electrodes in this method. The current flows in the muscles and blood vessels, which have relatively low resistivity levels in the human body. This method is used to measure bio-impedance changes following volume changes of muscles and blood vessels around a knee joint. The result of the bio-impedance changes is used to evaluate the movements. However, the method using the standard disposable electrodes has a restriction related to its low bio-impedance changes: the standard disposable electrodes are only able to measure bio-impedance from a limited part of a muscle. Moreover, it is impossible to use continuously, as the electrodes are designed to be disposable. This paper describes a conductive fabric sensor (CFS using a bio-impedance measurement method and determines the optimum configuration of the sensor for estimating knee joint movements. Methods The upper side of subjects' lower limbs was divided into two areas and the lower side of subjects' lower limbs was divided into three areas. The spots were matched and 6 pairs were selected. Subjects were composed of 15 males (age: 30.7 ± 5.3, weight: 69.8 ± 4.2 kg, and height: 173.5 ± 2.8 cm with no known problems with their knee joints. Bio-impedance changes according to knee joint flexion/extension assessments were calculated and compared with bio-impedance changes by an ankle joint flexion/extension test (SNR I and a hip joint flexion/extension test (SNR II. Results The bio-impedance changes of the knee joint flexion/extension assessment were 35.4 ± 20.0 Ω on the (1, 5 pair. SNR I was 3.8 ± 8.4 and SNR II was 6.6 ± 7.9 on the (1, 5 pair. Conclusions The optimum conductive fabric sensor configuration for evaluating knee joint movements were represented by

Comparative analysis between radiographic views for knee osteoarthrosis (bipedal AP versus monopedal AP

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Rodrigo Pires e Albuquerque

2013-08-01

Full Text Available OBJECTIVE: A comparative analysis by applying the criteria of the original classification Ahlbäck in the anteroposterior (AP bipedal knee in extension and anteroposterior (AP monopodal knee in symptomatic knee arthrosis. With this analysis we intend to observe the agreement, any advantage or difference between the incidence and degree of joint involvement between the orthopedic surgeons and radiologists with the referring physician. METHODS: From January 2012 to March 2012, was a prospective study of 60 symptomatic arthrosis knees (60 patients, clinically selected group of outpatient knee and radiographic proposals submitted to the search. Of the 60 patients, 39 were female and 21 male, mean age 64 years (ranging from 50 to 84 years. Of the 60 knees studied, 37 corresponded to the right side and 23 on the left side. Statistical analysis was performed by Kappa statistics, which evaluates the interobserver agreement for qualitative data. RESULTS: According to the scale of Ahlbäck, there was a significant agreement (p < 0.0001 intra-observer in the classification of knee osteoarthritis among the five evaluators. There was a significant agreement (p < 0.0001 with inter-observer referring physician in the incidence of AP monopodal and AP bipedal for the four raters. CONCLUSION: The study found no difference between the incidence in the AP monopodal versus AP bipedal in osteoarthritis of the knee.

Clinical outcome of increased flexion gap after total knee arthroplasty. Can controlled gap imbalance improve knee flexion?

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Ismailidis, P; Kuster, M S; Jost, B; Giesinger, K; Behrend, H

2017-06-01

Increased range of motion (ROM) while maintaining joint stability is the goal of modern total knee arthroplasty (TKA). A biomechanical study has shown that small increases in flexion gap result in decreased tibiofemoral force beyond 90° flexion. The purpose of this paper was to investigate clinical implications of controlled increased flexion gap. Four hundred and four TKAs were allocated into one of two groups and analysed retrospectively. In the first group (n = 352), flexion gap exceeded extension gap by 2.5 mm, while in the second group (n = 52) flexion gap was equal to the extension gap. The procedures were performed from 2008 to 2012. The patients were reviewed 12 months postoperatively. Objective clinical results were assessed for ROM, mediolateral and sagittal stability. Patient-reported outcome measures were the WOMAC score and the Forgotten Joint Score (FJS-12). After categorizing postoperative flexion into three groups (poor < 90°, satisfactory 91°-119°, good ≥ 120°) significantly more patients in group 1 achieved satisfactory or good ROM (p = 0.006). Group 1 also showed a significantly higher mean FJS-12 (group 1: 73, group 2: 61, p = 0.02). The mean WOMAC score was 11 in the first and 14 in the second group (n.s.). Increase in flexion gap did not influence knee stability. The clinical relevance of this study is that a controlled flexion gap increase of 2.5 mm may have a positive effect on postoperative flexion and patient satisfaction after TKA. Neither knee stability in the coronal and sagittal planes nor complications were influenced by a controlled increase in flexion gap. III.

Jumper's Knee (Patellar Tendonitis)

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... Safe Videos for Educators Search English Español Jumper's Knee KidsHealth / For Teens / Jumper's Knee What's in this ... continued damage to the knee. How Does the Knee Work? To understand how jumper's knee happens, it ...

Ground reaction forces and knee kinetics during single and repeated badminton lunges.

Science.gov (United States)

Lam, Wing Kai; Ding, Rui; Qu, Yi

2017-03-01

Repeated movement (RM) lunge that frequently executed in badminton might be used for footwear evaluation. This study examined the influence of single movement (SM) and RM lunges on the ground reaction forces (GRFs) and knee kinetics during the braking phase of a badminton lunge step. Thirteen male university badminton players performed left-forward lunges in both SM and RM sessions. Force platform and motion capturing system were used to measure GRFs and knee kinetics variables. Paired t-test was performed to determine any significant differences between SM and RM lunges regarding mean and coefficient of variation (CV) in each variable. The kinetics results indicated that compared to SM lunges, the RM lunges had shorter contact time and generated smaller maximum loading rate of impact force, peak knee anterior-posterior force, and peak knee sagittal moment but generated larger peak horizontal resultant forces (Ps < 0.05). Additionally, the RM lunges had lower CV for peak knee medial-lateral and vertical forces (Ps < 0.05). These results suggested that the RM testing protocols had a distinct loading response and adaptation pattern during lunge and that the RM protocol showed higher within-trial reliability, which may be beneficial for the knee joint loading evaluation under different interventions.

Knee extensor muscle weakness is a risk factor for development of knee osteoarthritis

DEFF Research Database (Denmark)

Oiestad, B E; Juhl, C B; Eitzen, I

2015-01-01

The objective of this study was to perform a systematic review and meta-analysis on the association between knee extensor muscle weakness and the risk of developing knee osteoarthritis. A systematic review and meta-analysis was conducted with literature searches in Medline, SPORTDiscus, EMBASE......, CINAHL, and AMED. Eligible studies had to include participants with no radiographic or symptomatic knee osteoarthritis at baseline; have a follow-up time of a minimum of 2 years, and include a measure of knee extensor muscle strength. Hierarchies for extracting data on knee osteoarthritis and knee...... extensor muscle strength were defined prior to data extraction. Meta-analysis was applied on the basis of the odds ratios (ORs) of developing symptomatic knee osteoarthritis or radiographic knee osteoarthritis in subjects with knee extensor muscle weakness. ORs for knee osteoarthritis and 95% confidence...

Effects of squat lift training and free weight muscle training on maximum lifting load and isolinetic peak torque of young adults without impairments.

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Yeung, S S; Ng, G Y

2000-06-01

Manual lifting is a frequent cause of back injury, and there is no evidence as to which training mode can provide the best training effect for lifting performance and muscle force. The purpose of this study was to examine the effects of a squat lift training and a free weight muscle training program on the maximum lifting load and isokinetic peak torque in subjects without known neuromuscular or musculoskeletal impairments. Thirty-six adults (20 male, 16 female) without known neuromuscular or musculoskeletal impairments participated. The subjects' mean age was 21.25 years (SD=1.16, range=20-24). Subjects were divided into 3 groups. Subjects in group 1 (n=12) performed squat lift training. Subjects in group 2 (n=12) participated in free weight resistance training of their shoulder abductors, elbow flexors, knee extensors and trunk extensors. Subjects in group 3 (n=12) served as controls. The maximum lifting load and isokinetic peak torques of the trunk extensors, knee extensors, elbow flexors, and shoulder abductors of each subject were measured before and after the study. Training was conducted on alternate days for 4 weeks, with an initial load of 80% of each subject's maximum capacity and with the load increased by 5% weekly. All groups were comparable for all measured variables before the study. After 4 weeks, subjects in groups 1 and 2 demonstrated more improvement in maximum lifting load and isokinetic peak torque of the back extensors compared with the subjects in group 3, but the 2 training groups were not different. The findings demonstrate that both squat lift and free weight resistance training are equally effective in improving the lifting load and isokinetic back extension performance of individuals without impairments.

Analgesic efficacy of intracapsular and intra-articular local anaesthesia for knee arthroplasty

DEFF Research Database (Denmark)

Andersen, L Ø; Husted, H; Kristensen, B B

2010-01-01

The optimal site for wound delivery of local anaesthetic after total knee arthroplasty is undetermined. Sixty patients having total knee arthroplasty received intra-operative infiltration analgesia with ropivacaine 0.2% and were then were randomly assigned to receive either intracapsular or intra......-articular catheters with 20 ml ropivacaine 0.5% given at 6 h and again at 24 h, postoperatively. Analgesic efficacy was assessed for 3 h after each injection, using a visual analogue score, where 0 = no pain and 100 = worst pain. There was no statistically significant difference between groups. Maximum pain relief...

Composition of The Knee Index, a novel three-dimensional biomechanical index for knee joint load, in subjects with mild to moderate knee osteoarthritis

DEFF Research Database (Denmark)

Clausen, Brian; Andriacchi, Tom; Nielsen, Dennis Brandborg

Background Knee joint load is an important factor associated with progression of knee osteoarthritis. To provide an overall understanding of knee joint loading, the Knee Index (KI) has been developed to include moments from all three planes (frontal, sagittal and transversal). However, before KI...... index of joint load for the knee, in patients with mild to moderate knee osteoarthritis. Methods The contribution of frontal, sagittal and transversal plane knee moments to KI was investigated in 24 subjects (13 women, age: 58 ± 7.6 years, BMI: 27.1 ± 3.0) with clinically diagnosed mild to moderate knee...... kinematics (i.e. the knee adduction moment), and secondarily the sagittal plane kinematics (i.e. the knee flexion moment). This holds promise for using KI in clinical trials since both frontal and sagittal knee joint moments have been suggested to be associated with the knee osteoarthritis disease...

MRI evaluation of acute articular cartilage injury of knee

International Nuclear Information System (INIS)

Zhang Jun; Wu Zhenhua; Fan Guoguang; Pan Shinong; Guo Qiyong

2003-01-01

Objective: To study the MRI manifestation of acute articular cartilage injury of knee for evaluating the extension and degree of the injury and guiding treatment. Methods: MRI of 34 patients with acute articular cartilage injury of knee within one day to fifteen days confirmed by arthroscopy and arthrotomy was reviewed and analyzed, with emphasis on articular cartilage and subchondral lesion. And every manifestation on MRI and that of arthroscopy and operation was compared. Results: The articular cartilage injury was diagnosed on MRI in 29 of 34 cases. Cartilage signal changes were found only in 4. The changes of cartilage shape were variable. Thinning of focal cartilage was showed in 3, osteochondral impaction in 3, creases of cartilage in 3, disrupted cartilage with fissuring in 13, cracks cartilage in 2, and cracks cartilage with displaced fragment in 1. Bone bruise and occult fracture were found only on MRI. Conclusion: The assessment of MRI and arthroscopy in acute articular cartilage injury are consistent. Combined with arthroscopy, MRI can succeed in assessing the extension and degree of acute articular injury and allowing treatment planning

Arthroscopic treatment of patients with moderate arthrofibrosis after total knee replacement.

Science.gov (United States)

Jerosch, Joerg; Aldawoudy, Akram M

2007-01-01

The purpose of this study was to document the effect of arthroscopic management in patients with knee stiffness after total knee replacement. We present a case series study, in which 32 patients have been treated for moderate arthrofibrosis of the knee after total knee replacement, with the same regimen. We have excluded all cases of stiffness, because of infection, mechanical mal-alignment, loosening of the implants and other obvious reasons of stiffness of the knee, rather than pure arthrofibrosis. All patients first underwent a trial of conservative treatment before going for arthroscopic management. A pain catheter for femoral nerve block was inserted just before anesthesia for post-operative pain management. Arthroscopic arthrolysis of the intra-articular pathology was performed in a standardized technique with release of all fibrous bands in the suprapatellar pouch, reestablishing the medial and lateral gutter, release of the patella, resection of the remaining meniscal tissue or an anterior cyclops, if needed. Intensive physiotherapy and continuous passive motion were to start immediately post-operatively. All the patients were available for the follow up and they were evaluated using the knee society rating system. A total of 25 of the 32 procedures resulted in an improvement of the patients knee score. All the knees operated upon had intra-articular fibrous bands, hypertrophic synovitis and peri-patellar adhesions. A total of eight patients suffered from an anterior cyclops lesion and six patients showed pseudomenicus. In 19 cases a medial and lateral relapse of the patella was performed; only 5 patients got an isolated lateral release. The mean knee flexion was 119 degrees (100-130) at the end of arthroscopy and was 97 degrees (75-115) at the last follow up. The eight patients with extension lags decreased from 27 degrees (10 degrees-35 degrees) pre-operatively to 4 degrees (0-10) at time of follow up. The average knee society ratings increased from 70

The Knee injury and Osteoarthritis Outcome Score (KOOS: from joint injury to osteoarthritis

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Roos Ewa M

2003-11-01

Full Text Available Abstract The Knee injury and Osteoarthritis Outcome Score (KOOS was developed as an extension of the WOMAC Osteoarthritis Index with the purpose of evaluating short-term and long-term symptoms and function in subjects with knee injury and osteoarthritis. The KOOS holds five separately scored subscales: Pain, other Symptoms, Function in daily living (ADL, Function in Sport and Recreation (Sport/Rec, and knee-related Quality of Life (QOL. The KOOS has been validated for several orthopaedic interventions such as anterior cruciate ligament reconstruction, meniscectomy and total knee replacement. In addition the instrument has been used to evaluate physical therapy, nutritional supplementation and glucosamine supplementation. The effect size is generally largest for the subscale QOL followed by the subscale Pain. The KOOS is a valid, reliable and responsive self-administered instrument that can be used for short-term and long-term follow-up of several types of knee injury including osteoarthritis. The measure is relatively new and further use of the instrument will add knowledge and suggest areas that need to be further explored and improved.

A comparison of men's and women's strength to body mass ratio and varus/valgus knee angle during jump landings.

Science.gov (United States)

Haines, Tracie L; McBride, Jeffrey M; Triplett, N Travis; Skinner, Jared W; Fairbrother, Kimberly R; Kirby, Tyler J

2011-10-01

The purpose of this investigation was to compare valgus/varus knee angles during various jumps and lower body strength between males and females relative to body mass. Seventeen recreationally active females (age: 21.94 ± 2.59 years; height: 1.67 ± 0.05 m; mass: 64.42 ± 8.39 kg; percent body fat: 26.89 ± 6.26%; squat one-repetition maximum: 66.18 ± 19.47 kg; squat to body mass ratio: 1.03 ± 0.28) and 13 recreationally active males (age: 21.69 ± 1.65 years; height: 1.77 ± 0.07 m; mass: 72.39 ± 9.23 kg; percent body fat: 13.15 ± 5.18%; squat one-repetition maximum: 115.77 ± 30.40 kg; squat to body mass ratio: 1.59 ± 0.31) performed a one-repetition maximum in the squat and three of each of the following jumps: countermovement jump, 30 cm drop jump, 45 cm drop jump, and 60 cm drop jump. Knee angles were analysed using videography and body composition was analysed by dual-energy X-ray absorptiometry to allow for squat to body mass ratio and squat to fat free mass ratio to be calculated. Significant differences (P ≤ 0.05) were found between male and female one-repetition maximum, male and female squat to body mass ratio, and male and female squat to fat free mass ratio. Significant differences were found between male and female varus/valgus knee positions during maximum flexion of the right and left leg in the countermovement jump, drop jump from 30 cm, drop jump from 45 cm, and drop jump from 60 cm. Correlations between varus/valgus knee angles and squat to body mass ratio for all jumps displayed moderate, non-significant relationships (countermovement jump: r = 0.445; drop jump from 30 cm: r = 0.448; drop jump from 45 cm: r = 0.449; drop jump from 60 cm: r = 0.439). In conclusion, males and females have significantly different lower body strength and varus/valgus knee position when landing from jumps.

Knee Arthroscopy Simulation: A Randomized Controlled Trial Evaluating the Effectiveness of the Imperial Knee Arthroscopy Cognitive Task Analysis (IKACTA) Tool.

Science.gov (United States)

Bhattacharyya, Rahul; Davidson, Donald J; Sugand, Kapil; Bartlett, Matthew J; Bhattacharya, Rajarshi; Gupte, Chinmay M

2017-10-04

Virtual-reality and cadaveric simulations are expensive and not readily accessible. Innovative and accessible training adjuncts are required to help to meet training needs. Cognitive task analysis has been used extensively to train pilots and in other surgical specialties. However, the use of cognitive task analyses within orthopaedics is in its infancy. The purpose of this study was to evaluate the effectiveness of a novel cognitive task analysis tool to train novice surgeons in diagnostic knee arthroscopy in high-fidelity, phantom-limb simulation. Three expert knee surgeons were interviewed independently to generate a list of technical steps, decision points, and errors for diagnostic knee arthroscopy. A modified Delphi technique was used to generate the final cognitive task analysis. A video and a voiceover were recorded for each phase of this procedure. These were combined to produce the Imperial Knee Arthroscopy Cognitive Task Analysis (IKACTA) tool that utilizes written and audiovisual stimuli to describe each phase of a diagnostic knee arthroscopy. In this double-blinded, randomized controlled trial, a power calculation was performed prior to recruitment. Sixteen novice orthopaedic trainees who performed ≤10 diagnostic knee arthroscopies were randomized into 2 equal groups. The intervention group (IKACTA group) was given the IKACTA tool and the control group had no additional learning material. They were assessed objectively (validated Arthroscopic Surgical Skill Evaluation Tool [ASSET] global rating scale) on a high-fidelity, phantom-knee simulator. All participants, using the Likert rating scale, subjectively rated the tool. The mean ASSET score (and standard deviation) was 19.5 ± 3.7 points in the IKACTA group and 10.6 ± 2.3 points in the control group, resulting in an improvement of 8.9 points (95% confidence interval, 7.6 to 10.1 points; p = 0.002); the score was determined as 51.3% (19.5 of 38) for the IKACTA group, 27.9% (10.6 of 38) for the

Real-Time Tracking of Knee Adduction Moment in Patients with Knee Osteoarthritis

Science.gov (United States)

Kang, Sang Hoon; Lee, Song Joo; Zhang, Li-Qun

2014-01-01

Background The external knee adduction moment (EKAM) is closely associated with the presence, progression, and severity of knee osteoarthritis (OA). However, there is a lack of convenient and practical method to estimate and track in real-time the EKAM of patients with knee OA for clinical evaluation and gait training, especially outside of gait laboratories. New Method A real-time EKAM estimation method was developed and applied to track and investigate the EKAM and other knee moments during stepping on an elliptical trainer in both healthy subjects and a patient with knee OA. Results Substantial changes were observed in the EKAM and other knee moments during stepping in the patient with knee OA. Comparison with Existing Method(s) This is the first study to develop and test feasibility of real-time tracking method of the EKAM on patients with knee OA using 3-D inverse dynamics. Conclusions The study provides us an accurate and practical method to evaluate in real-time the critical EKAM associated with knee OA, which is expected to help us to diagnose and evaluate patients with knee OA and provide the patients with real-time EKAM feedback rehabilitation training. PMID:24361759

Smartphone Photography as a Tool to Measure Knee Range of Motion.

Science.gov (United States)

Mica, Megan Conti; Wagner, Eric R; Shin, Alexander Y

2018-01-01

The objective of this study was to validate measuring knee range of motion (ROM) from smartphone photography. Thirty-two participants (64 knees) obtained smartphone photographs of knee flexion and extension. Surgeons obtained the same photographs and goniometric measurement of ROM. ROM was measured using Adobe Photoshop. Goniometer versus digital measurements, participant versus surgeon photographs, and interobserver measurements were analyzed. The average difference in goniometer and digital photograph measurements was 5°. The interclass correlation was .642(L) and .656(R). The Bland-Altman plots demonstrated that 29/32 digital measurements were within the 95% confidence interval (CI). Participants' versus researchers' photographs averaged a 2° difference. The interclass correlation was .924(L) and .91(R). Bland-Altman plots demonstrated that 31/32 measurements were within the 95% CI. Interobserver reliability averaged aROMdifference of 5°. The concordance coefficients were .647(L) and .723(R). Bland-Altman plots demonstrated that 30 of 32 digital measurements were within the 95% CI. Measuring knee ROM using smartphone digital photography is valid and reliable. (Journal of Surgical Orthopaedic Advances 27(1):52-57, 2018).

Knee Deformities in Children With Down Syndrome: A Focus on Knee Malalignment.

Science.gov (United States)

Duque Orozco, Maria Del Pilar; Abousamra, Oussama; Chen, Brian Po-Jung; Rogers, Kenneth J; Sees, Julieanne P; Miller, Freeman

Patellofemoral instability (PFI) has been the most reported knee abnormality in people with Down syndrome. Other reported knee abnormalities have been associated with PFI and different management approaches have been described with variable outcomes. The aim of this study was to describe the anatomic variations of the knee in children with Down syndrome. A comparison between knees with and without PFI was performed and our experience in treating knee abnormalities in Down syndrome was also reported. Records of all children with Down syndrome were reviewed. Two groups were identified (knees with and without PFI). Radiographic measurements included the mechanical and anatomic lateral distal femoral angles, medial proximal tibial angle, angle of depression of medial tibial plateau, lateral tibial translation, and distal femoral physis-joint angle. On the lateral view, Insall-Salvati and Blackburne-Peel ratios were measured. The sulcus angle was measured on the tangential view. Measurements were compared between the 2 groups (with and without PFI).Knees with PFI were divided into 3 subgroups based on their treatment (group A: surgical valgus correction, group B: surgical soft tissue procedures for PFI, and group C: conservative treatment). Preoperative radiographs were used for the surgical group and last available radiographs were used for the conservative group. Clinical and radiographic data were compared between the groups. For groups A and B, clinical and radiographic data were also compared between preoperative and last visits. Of the 581 children with Down syndrome, 5% (31 children: 22 females, 9 males) had PFI in 56 knees. Mean age at diagnosis was 11.5±3.5 years. Of the remaining 550 children, 75 children had radiographs for 130 knees. Knees with PFI had significantly more valgus and a larger distal femoral physis-joint angle. Depression of the medial tibial plateau and lateral tibial translation were noted in knees with PFI. Insall-Salvati ratio was higher

Dosimetry of β extensive sources

International Nuclear Information System (INIS)

Rojas C, E.L.; Lallena R, A.M.

2002-01-01

In this work, we have been studied, making use of the Penelope Monte Carlo simulation code, the dosimetry of β extensive sources in situations of spherical geometry including interfaces. These configurations are of interest in the treatment of the called cranealfaringyomes of some synovia leisure of knee and other problems of interest in medical physics. Therefore, its application can be extended toward problems of another areas with similar geometric situation and beta sources. (Author)

Arthroscopic-assisted Arthrodesis of the Knee Joint With the Ilizarov Technique: A Case Report and Literature Review.

Science.gov (United States)

Waszczykowski, Michal; Niedzielski, Kryspin; Radek, Maciej; Fabis, Jaroslaw

2016-01-01

Arthrodesis of the knee joint is a mainly a salvage surgical procedure performed in cases of infected total knee arthroplasty, tumor, failed knee arthroplasty or posttraumatic complication.The authors report the case of 18-year-old male with posttraumatic complication of left knee because of motorbike accident 1 year before. He was treated immediately after the injury in the local Department of Orthopaedics and Traumatology. The examination in the day of admission to our department revealed deformation of the left knee, massive scar tissue adhesions to the proximal tibial bone and multidirectional instability of the knee. The plain radiographs showed complete lack of lateral compartment of the knee joint and patella. The patient complained of severe instability and pain of the knee and a consecutive loss of supporting function of his left limb. The authors decided to perform an arthroscopic-assisted fusion of the knee with Ilizarov external fixator because of massive scar tissue in the knee region and the prior knee infection.In the final follow-up after 54 months a complete bone fusion, good functional and clinical outcome were obtained.This case provides a significant contribution to the development and application of low-invasive techniques in large and extensive surgical procedures in orthopedics and traumatology. Moreover, in this case fixation of knee joint was crucial for providing good conditions for the regeneration of damaged peroneal nerve.

EFFECT OF DIFFERENT LEVELS OF LOCALIZED MUSCLE FATIGUE ON KNEE POSITION SENSE

Directory of Open Access Journals (Sweden)

William S. Gear

2011-12-01

Full Text Available There is little information available regarding how proprioceptive abilities decline as the amount of exertion increases during exercise. The purpose of this study was to determine the role of different levels of fatigue on knee joint position sense. A repeated measures design was used to examine changes in active joint reposition sense (AJRS prior to and following three levels of fatigue. Eighteen participants performed knee extension and flexion isokinetic exercise until torque output was 90%, 70%, or 50% of the peak hamstring torque for three consecutive repetitions. Active joint reposition sense at 15, 30, or 45 degrees was tested following the isokinetic exercise session. Following testing of the first independent measure, participants were given a 20 minute rest period. Testing procedures were repeated for two more exercise sessions following the other levels of fatigue. Testing of each AJRS test angle was conducted on three separate days with 48 hours between test days. Significant main effect for fatigue was indicated (p = 0.001. Pairwise comparisons indicated a significant difference between the pre-test and following 90% of peak hamstring torque (p = 0.02 and between the pre-test and following 50% of peak hamstring torque (p = 0.02. Fatigue has long been theorized to be a contributing factor in decreased proprioceptive acuity, and therefore a contributing factor to joint injury. The findings of the present study indicate that fatigue may have an effect on proprioception following mild and maximum fatigue.

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

Science.gov (United States)

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

2013-01-01

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

Gender differences of sagittal knee and ankle biomechanics during stair-to-ground descent transition.

Science.gov (United States)

Hong, Yoon No Gregory; Shin, Choongsoo S

2015-12-01

Falls on stairs often result in severe injury and occur twice as frequently in women. However, gender differences in kinetics and kinematics during stair descent are unknown. Thus, this study aimed to determine whether gender differences of knee and ankle biomechanics exist in the sagittal plane during the stair-to-ground descending transition. It was hypothesized that 1) women would reveal higher ground-toe-trochanter angle and lower ground-toe length during stair-to-ground descent transition than men; and 2) women would reveal lower peak knee extension moment during stair-to-ground descent transition than men. Fifteen men and fifteen women were recruited and performed a stair descent activity. Kinetic and kinematic data were obtained using a force plate and motion capture system. The women performed the stair descent with a lower peak knee extension moment and a peak knee power at the early weight acceptance phase. The women also revealed a higher ground-toe-trochanter angle and a lower ground-toe length, which indicated a more forward position of the lower extremity relative to the toe contact point at both the initial contact and at the time of peak kinematic and kinetic events. This study found that knee and ankle kinematics and kinetics differed significantly between the genders due to differences in ground-toe-trochanter angle. Women have a different stair descending strategy that reduces the demand of the lower extremity muscle function, but this strategy seems to increase the risk of falls. Copyright © 2015 Elsevier Ltd. All rights reserved.

[Mini-subvastus approach for total knee replacement].

Science.gov (United States)

Halder, Andreas; Beier, Alexander; Neumann, Wolfram

2009-03-01

Total knee replacement in minimally invasive technique without any trauma to the extensor apparatus and with soft-tissue-referenced bone resections. Only the subvastus approach preserves the integrity of the extensor apparatus and has therefore been modified to become a minimally invasive technique with a shorter skin incision and lateralization instead of eversion of the patella. Soft-tissue balancing is done through this direct anterior approach. Mild to moderate varus osteoarthritis of the knee up to 15 degrees of malalignment, mild and passively correctable valgus osteoarthritis of the knee up to 10 degrees of malalignment. Severe, contract varus osteoarthritis of the knee, severe and moderate, contract valgus osteoarthritis of the knee, severe obesity, exceptionally muscular patients, decreased skin perfusion. Central skin incision from the superior pole of the patella to the tibial tubercle. Exposure of the medial retinaculum and mobilization of the vastus medialis muscle subcutaneously. Incision of the medial retinaculum and blunt separation of the vastus medialis muscle from the intermuscular septum. Lateralization of the patella and flexion of the knee joint. Resection of the tibia perpendicular to the diaphysis. Adjustment of the anteroposterior (AP) resection block at the level of the anterior femoral cortex and of rotation by applying equal tension to the collateral ligaments. Balancing of soft-tissue tension in flexion gap by release, if necessary. After AP resection fixation of distal resection block in planned valgus angle. Balancing of soft-tissue tension in extension gap by release, if necessary. After distal femur resection facet resection, adaptation of posterior femoral condyles, and implantation of prosthesis. Check on stability and range of motion. Wound closure. Full weight bearing from the 1st postoperative day, CPM (continuous passive motion) with up to 90 degrees flexion with peridural anesthesia as tolerated, stair climbing starting on

RELIABILITY AND RESPONSIVENESS OF THE DANISH MODIFIED INTERNATIONAL KNEE DOCUMENTATION COMMITTEE SUBJECTIVE KNEE FORM FOR CHILDREN WITH KNEE DISORDERS

DEFF Research Database (Denmark)

Jacobsen, Julie Sandell; Knudsen, Pernille; Fynbo, Charlotte

2016-01-01

Introduction The modified international Knee Documentation Committee Subjective Knee Form (Pedi-IKDC) is a widely used patient-reported tool applicable for children with knee disorders ranging on a scale from 0-100. We aimed to translate the Pedi-IKDC Subjective Knee Form into Danish......, and furthermore to assess its reliability and responsiveness. Material and Methods The Pedi-IKDC Subjective Knee Form was translated to Danish according to international guidelines. Reliability was assessed with Bland Altman plots, standard error of measurement (SEM), Minimal Detectable Change (MDC) and the Intra....... Reliability and responsiveness were assessed in 50 children (median 15 years) referred to hospital due to different knee disorders. Results The SEM was 4.2 points and the MDC was 11.5 points. The ICC was 0.91 (0.9-1.0). The change score of the Pedi-IKDC Subjective Knee form was correlated to the external...

An investigation of rugby scrimmaging posture and individual maximum pushing force.

Science.gov (United States)

Wu, Wen-Lan; Chang, Jyh-Jong; Wu, Jia-Hroung; Guo, Lan-Yuen

2007-02-01

Although rugby is a popular contact sport and the isokinetic muscle torque assessment has recently found widespread application in the field of sports medicine, little research has examined the factors associated with the performance of game-specific skills directly by using the isokinetic-type rugby scrimmaging machine. This study is designed to (a) measure and observe the differences in the maximum individual pushing forward force produced by scrimmaging in different body postures (3 body heights x 2 foot positions) with a self-developed rugby scrimmaging machine and (b) observe the variations in hip, knee, and ankle angles at different body postures and explore the relationship between these angle values and the individual maximum pushing force. Ten national rugby players were invited to participate in the examination. The experimental equipment included a self-developed rugby scrimmaging machine and a 3-dimensional motion analysis system. Our results showed that the foot positions (parallel and nonparallel foot positions) do not affect the maximum pushing force; however, the maximum pushing force was significantly lower in posture I (36% body height) than in posture II (38%) and posture III (40%). The maximum forward force in posture III (40% body height) was also slightly greater than for the scrum in posture II (38% body height). In addition, it was determined that hip, knee, and ankle angles under parallel feet positioning are factors that are closely negatively related in terms of affecting maximum pushing force in scrimmaging. In cross-feet postures, there was a positive correlation between individual forward force and hip angle of the rear leg. From our results, we can conclude that if the player stands in an appropriate starting position at the early stage of scrimmaging, it will benefit the forward force production.

The relationship between leg preference and knee mechanics during sidestepping in collegiate female footballers.

Science.gov (United States)

Brown, Scott R; Wang, Henry; Dickin, D Clark; Weiss, Kaitlyn J

2014-11-01

This study examined the relationship between leg preference and knee mechanics in females during sidestepping. Three-dimensional data were recorded on 16 female collegiate footballers during a planned 45° sidestep manoeuvre with their preferred and non-preferred kicking leg. Knee kinematics and kinetics during initial contact, weight acceptance, peak push-off, and final push-off phases of sidestepping were analysed in both legs. The preferred leg showed trivial to small increases (ES = 0.19-0.36) in knee flexion angle at initial contact, weight acceptance, and peak push-off, and small increases (ES = 0.21-0.34) in peak power production and peak knee extension velocity. The non-preferred leg showed a trivial increase (ES = 0.10) in knee abduction angle during weight acceptance; small to moderate increases (ES = 0.22-0.64) in knee internal rotation angle at weight acceptance, peak push-off, and final push-off; a small increase (ES = 0.22) in knee abductor moment; and trivial increases (ES = 0.09-0.14) in peak power absorption and peak knee flexion velocity. The results of this study show that differences do exist between the preferred and non-preferred leg in females. The findings of this study will increase the knowledge base of anterior cruciate ligament injury in females and can aid in the design of more appropriate neuromuscular, plyometric, and strength training protocols for injury prevention.

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

DEFF Research Database (Denmark)

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....

Dissecting the contribution of knee joint NGF to spinal nociceptive sensitization in a model of OA pain in the rat.

Science.gov (United States)

Sagar, D R; Nwosu, L; Walsh, D A; Chapman, V

2015-06-01

Although analgesic approaches targeting nerve growth factor (NGF) for the treatment of osteoarthritis (OA) pain remain of clinical interest, neurophysiological mechanisms by which NGF contribute to OA pain remain unclear. We investigated the impact of local elevation of knee joint NGF on knee joint, vs remote (hindpaw), evoked responses of spinal neurones in a rodent model of OA pain. In vivo spinal electrophysiology was carried out in anaesthetised rats with established pain behaviour and joint pathology following intra-articular injection of monosodium iodoacetate (MIA), vs injection of saline. Neuronal responses to knee joint extension and flexion, mechanical punctate stimulation of the peripheral receptive fields over the knee and at a remote site (ipsilateral hind paw) were studied before, and following, intra-articular injection of NGF (10 μg/50 μl) or saline. MIA-injected rats exhibited significant local (knee joint) and remote (lowered hindpaw withdrawal thresholds) changes in pain behaviour, and joint pathology. Intra-articular injection of NGF significantly (P knee extension-evoked firing of spinal neurones and the size of the peripheral receptive fields of spinal neurones (100% increase) over the knee joint in MIA rats, compared to controls. Intra-articular NGF injection did not significantly alter responses of spinal neurones following noxious stimulation of the ipsilateral hind paw in MIA-injected rats. The facilitatory effects of intra-articular injection of NGF on spinal neurones receiving input from the knee joint provide a mechanistic basis for NGF mediated augmentation of OA knee pain, however additional mechanisms may contribute to the spread of pain to remote sites. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Knee arthroscopy - discharge

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

Knee microfracture surgery

Science.gov (United States)

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

Preventing Knee Injuries

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... Our Newsletter Donate Blog Skip breadcrumb navigation Preventing Knee Injuries Knee injuries in children and adolescent athletes ... this PDF Share this page: WHAT ARE COMMON KNEE INJURIES? Pain Syndromes One of the most common ...

The efficacy of balneotherapy and mud-pack therapy in patients with knee osteoarthritis.

Science.gov (United States)

Evcik, Deniz; Kavuncu, Vural; Yeter, Abdurrahman; Yigit, Ilknur

2007-01-01

Knee osteoarthritis (OA) is a common chronic degenerative disorder. There are various treatment modalities. This study was planned to investigate the efficacy of balneotherapy, mud-pack therapy in patients with knee OA. A total of 80 patients with knee OA were included. Their ages ranged between 39-78. The patients were separated in to three groups. Group I (n=25) received balneotherapy, group II (n=29) received mud-pack therapy and group III (n=26) was hot-pack therapy group. The therapies were applied for 20 min duration, once a day, five times per week and a total of 10 session. Patients were assessed according to pain, functional capacity and quality of life parameters. Pain was assessed by using Visual Analogue Scale (VAS) and Western Ontario McMaster Osteoarthritis Index (WOMAC) pain scale (0-4 likert scale). Functional capacity was assessed by using WOMAC functional capacity and WOMAC global index. Quality of life was evaluated by Nottingham Health Profile (NHP) self-administered questionnaire. Also physician's global assessment and the maximum distance that patient can walk without pain, were evaluated. The assessment parameters were evaluated before and after three months. There were statistically significant improvement in VAS and WOMAC pain scores in group I (pbalneotherapy and mud-pack therapy groups (p0.05). The maximum distance was improved both in group I and II (pBalneotherapy and mud-pack therapy were effective in treating patients with knee OA.

Patients Unicondylar Knee Replacement vs. Total Knee Replacement

OpenAIRE

Hedra Eskander

2017-01-01

The aim of this review article is to analyse the clinical effectiveness of total knee replacement (TKR) compared to unicondylar knee replacement (UKR) on patients. In terms of survival rates, revision rates and postoperative complications. The keywords used were: knee arthroplasty. Nearly three thousand articles were found on 25 August 2016. Of those, only twenty-five were selected and reviewed because they were strictly focused on the topic of this article. Compared with those who have TKR, ...

Gender differences in the knee adduction moment after anterior cruciate ligament reconstruction surgery.

Science.gov (United States)

Webster, Kate E; McClelland, Jodie A; Palazzolo, Simon E; Santamaria, Luke J; Feller, Julian A

2012-04-01

The external knee adduction moment during gait has previously been associated with knee pain and osteoarthritis (OA). Recently, the knee adduction moment has been shown to be increased following anterior cruciate ligament (ACL) reconstruction surgery and has been suggested as a potential mechanism for the progression of early onset knee OA in this population. No study has investigated the gender differences in gait biomechanics following ACL reconstruction. To examine gender differences in gait biomechanics following ACL reconstruction surgery. 36 subjects (18 females, 18 males) who had previously undergone ACL reconstruction surgery (mean time since surgery 20 months) underwent gait analysis at a self-selected walking speed. Males and females were well matched for age, time since surgery and walking speed. Maximum flexion and adduction angles and moments were recorded during the stance phase of level walking and compared between the male and female groups. The knee adduction moment was 23% greater in the female compared with the male ACL group. No gender differences were seen in the sagittal plane. No differences were seen between the reconstructed and contralateral limb. The higher knee adduction moment seen in females compared with males may suggest an increased risk for the development of OA in ACL-reconstructed females.

Knee Confidence as it Relates to Self-Reported and Objective Correlates of Knee Osteoarthritis

DEFF Research Database (Denmark)

Skou, Søren T; Rasmussen, Sten; Simonsen, Ole

2015-01-01

osteoarthritis (OA). Background Lack of knee confidence is a frequent symptom in patients with knee OA, but little is known of associations between knee confidence and other common correlates of knee OA. Methods Baseline data from 220 patients with knee OA were applied in ordinal regression analyses, with knee...... confidence, assessed using item Q3 of the Knee injury and Osteoarthritis Outcome Score, as the dependent variable and self-reported (pain on walking, general health, fear of movement, self-efficacy, function, and previous serious injury) and objective measures (muscle strength, 20-m walk time.......21; 95% CI: 1.09, 1.34), and general health (OR = 0.024; 95% CI: 0.002, 0.259) explained 19% of the variance in knee confidence (Pcommon finding in individuals with knee OA. Pain on walking was confirmed as a correlate of knee confidence, whereas...

The effect of tourniquet use on fixation quality in cemented total knee arthroplasty a prospective randomized clinical controlled RSA trial.

Science.gov (United States)

Molt, Mats; Harsten, Andreas; Toksvig-Larsen, Sören

2014-03-01

A concern that arises with any change in technique is whether it affects the long-term implant stability. The objective of this study was to evaluate the early migration, measured by radiostereometric analysis (RSA), and the functional outcome of the Triathlon™ cemented knee prosthesis, operated on with or without a tourniquet. During the last decades RSA has emerged as a way to assess prosthetic fixation and long time prognosis. The method has been used extensively in both hip and knee arthroplasty. This was a single centre prospective study including 60 patients randomized into two groups operated on either with or without tourniquet. RSA investigation was done within 2-3 days postoperatively after full weight bearing, and then at 3 months, 1 year and 2 years postoperatively. There were no differences between the groups regarding the translation along or rotation around the three coordinal axes, or in maximum total point motion (MTPM). At 2 years the mean MTPM (SD) was 0.71 mm (0.64) for the tourniquet-group and 0.53 mm (0.21) for the non-tourniquet-group. The tibial tray of the Triathlon™ cemented knee prosthesis showed similar early stability whether operated on with or without tourniquet. Level I. Article focus: A safety study for total knee replacement operated on with or without perioperative tourniquet regarding the prosthetic fixation. Strengths and limitations: Strength of this study is that it is a randomized prospective trial using an objective measuring tool. The sample size of 25-30 patients is reportedly sufficient for the screening of implants using RSA (1-3). Clinical trials NCT01604382, Ethics Committee approval D-nr: 144/20085. © 2013.

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

Science.gov (United States)

Takeda, Hideki; Nakagawa, Takumi; Nakamura, Kozo; Engebretsen, Lars

2011-04-01

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 (narrowing joint space, osteophyte formation and subchondral sclerosis). There is no strong correlation between symptoms and radiographic findings. The aetiology of knee osteoarthritis is multifactorial. Excessive musculoskeletal loading (at work or in sports), high body mass index, previous knee injury, female gender and muscle weakness are well-known risk factors. The high-level athlete with a major knee injury has a high incidence of knee osteoarthritis. Cartilage injuries are frequently observed in young and middle-aged active athletes. Often this injury precedes osteoarthritis. Reducing risk factors can decrease the prevalence of knee osteoarthritis. The prevention of knee injury, especially anterior cruciate ligament and meniscus injury in sports, is important to avoid progression of knee osteoarthritis.

CRPS Knee: How frequently encountered in differential diagnosis of Knee pain?

Science.gov (United States)

Aggarwal, Aakanksha; Agarwal, Anil

2018-04-13

We have read with great interest the paper by Catelijne M. van Bussel [1] recently published in Pain Practice. I wish to congratulate the authors for their valuable contributions. In the said article, 12 patients who had complex regional pain syndrome confined to the knee have been included. Though reports have been published involving primarily the knee after total knee arthroplasty [2,3] the incidence of CRPS knee following trauma or otherwise is not well appreciated. We would have appreciated if presence or absence of any inciting event for the development CRPS knee in these 12 patients could be mentioned, which could be helpful in a better diagnosis and management of the patients with CRPS knee. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Contact Mechanics and Failure Modes of Compliant Polymeric Bearing Materials for Knee Cartilage Replacement

Science.gov (United States)

Tohfafarosh, Mariya Shabbir

control samples. However, chemical spectra of electron beam sterilized samples revealed minor changes, which were absent in unsterilized and gamma sterilized samples. Upon successful sterilization evaluation, both polycarbonate urethane and the novel hydrogel were investigated for the contact mechanics of compliant-on-compliant artificial knee bearings using a finite element analysis approach. A simplified, axisymmetric, finite element model of a medial knee compartment was developed and validated, and a design of simulation experiments was carried out to evaluate the effect of implant conformity, implant thickness and material properties on the contact mechanics of compliant knee bearings under normal walking and stair climbing loads. All input parameters, namely, implant conformity, implant thickness and material properties, significantly (pengineering strain (39 - 53% true strain) without any signs of cracking or fracture. The tension was determined to be the primary failure mode for the proposed materials, and the tensile test was used to define the failure criteria of the materials. The unconfined compression tests were used to define the yield stresses and strains under compression, which is the main mode of loading for the knee joint. The results of the plane strain compression were modeled using a finite element model and the maximum principal stress, von Mises stress, maximum shear stress, and maximum principal strain failure criteria were predicted at the corresponding yield strain of each material formulation. Upon comparing the knee model contact stress and strain prediction under normal walking and stair climbing loads with those of the empirical failure criteria at yield, the polycarbonate urethane showed better overall potential for use in compliant knee implants, while the hydrogels exhibited higher potential for delamination or fracture, especially if appropriate implant conformity and thickness are not employed. The outcome of this study and the previous

Effect of compression therapy on knee swelling and pain after total knee arthroplasty

DEFF Research Database (Denmark)

Munk, Stig; Jensen, Niels J. F.; Andersen, Ida Bøgh

2013-01-01

PURPOSE: Knee swelling after total knee arthroplasty may impair postoperative mobilisation and training, and as medical elastic compression stockings are well tolerated and effective to prevent oedema, haematoma and postoperative pain after venous surgery, we wanted to study whether this effect...... could be transferred to total knee arthroplasty surgery reducing postoperative swelling and pain and thereby facilitating mobilisation and improving patient-reported knee function. METHODS: In a randomised controlled study, 88 patients were randomised to use either a medical elastic compression stocking...... or no stocking from the first postoperative day and the following 4 weeks after total knee arthroplasty. Outcome measures were knee, calf and ankle swelling, knee flexion, pain and patient-reported knee function. RESULTS: Seventy per cent of the swelling had occurred before application of the stocking the day...

Effect of posterior cruciate ligament creep on muscular co-activation around knee: a pilot study.

Science.gov (United States)

Cheng, Xiangrong; Zhang, Tailai; Shan, Xinhai; Wang, Jingyuan

2014-04-01

The effect of posterior cruciate ligament (PCL) on muscle co-activation (MCO) is not known though MCO has been extensively studied. The purpose of the study was to investigate the effect of PCL creep on MCO and on joint moment around the knee. Twelve males and twelve females volunteered for this study. PCL creep was estimated via tibial posterior displacement which was elicited by a 20kg dumbbell hanged on horizontal shank near patella for 10min. Electromyography activity from both rectus femoris and biceps femoris as well as muscle strength on the right thigh was recorded synchronically during knee isokinetic flexion-extension performance in speed of 60deg/s as well as 120deg/s on a dynamometer before and after PCL creep. A one-way ANOVA with repeated measures was used to evaluate the effect of creep, gender and speed. The results showed that significant tibial posterior displacement was found (p=0.01) in both male and female groups. No significant increase of joint moment was found in flexion as well as in extension phase in both female and male groups. There was a significant effect of speed (p=0.036) on joint moment in extension phase. Co-activation index (CI) decreased significantly (p=0.049) in extension phase with a significant effect of gender (p⩽0.001). It was concluded that creep developed in PCL due to static posterior load on the proximal tibia could significantly elicit the increase of the activation of agonist muscles but with no compensation from the antagonist in flexion as well as in extension phase. The creep significantly elicited the decrease of the antagonist-agonist CI in extension phase. MCO in females was reduced significantly in extension phase. It was suggested that PCL creep might be one of risk factors to the knee injury in sports activity. Copyright © 2014. Published by Elsevier Ltd.

Knee Injuries and Disorders

Science.gov (United States)

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

Association Between Pain at Sites Outside the Knee and Knee Cartilage Volume Loss in Elderly People Without Knee Osteoarthritis: A Prospective Study.

Science.gov (United States)

Pan, Feng; Laslett, Laura; Tian, Jing; Cicuttini, Flavia; Winzenberg, Tania; Ding, Changhai; Jones, Graeme

2017-05-01

Pain is common in the elderly. Knee pain may predict knee cartilage loss, but whether generalized pain is associated with knee cartilage loss is unclear. This study, therefore, aimed to determine whether pain at multiple sites predicts knee cartilage volume loss among community-dwelling older adults, and, if so, to explore potential mechanisms. Data from the prospective Tasmanian Older Adult Cohort study was utilized (n = 394, mean age 63 years, range 52-79 years). Experience of pain at multiple sites was assessed using a questionnaire at baseline. T1-weighted fat-saturated magnetic resonance imaging of the right knee was performed to assess the cartilage volume at baseline and after 2.6 years. Linear regression modeling was used with adjustment for potential confounders. The median number of painful sites was 3 (range 0-7). There was a dose-response relationship between the number of painful sites and knee cartilage volume loss in the lateral and total tibiofemoral compartments (lateral β = -0.28% per annum; total β = -0.25% per annum, both P for trend knee osteoarthritis (OA) (P pain medication, and knee structural abnormalities. The number of painful sites independently predicts knee cartilage volume loss, especially in people without knee OA, suggesting that widespread pain may be an early marker of more rapid knee cartilage loss in those without radiographic knee OA. The underlying mechanism is unclear, but it is independent of anthropometrics, physical activity, and knee structural abnormalities. © 2016, American College of Rheumatology.

Self-efficacy and its application in the treatment of knee osteoarthritis: a critical review

Directory of Open Access Journals (Sweden)

Ray Marks

2012-11-01

Full Text Available Symptomatic knee osteoarthritis, a prevalent progressively disabling disease affecting one or both knee joints requires extensive self-management. Self-efficacy, a psychological attribute generally denoting one’s perceived belief about their ability to successfully perform a particular behavior, including health behaviors, is a significant predictor of psychological well-being, adherence to prescribed treatments, and pain coping mechanisms in persons with various forms of chronic disease, including arthritis. This paper examines the available peer-reviewed research published over the last 35 years detailing: i the concept of self-efficacy, ii the relationship between self-efficacy and adjustment to arthritis, iii the research concerning self-efficacy in the context of knee osteoarthritis disability, and iv some promising approaches for promoting the wellbeing of adults with knee osteoarthritis through the application of self-efficacy theory and other approaches. Based on this data, directions for future research and practice are offered.

The MRI appearance of cystic lesions around the knee

International Nuclear Information System (INIS)

McCarthy, Catherine L.; McNally, Eugene G.

2004-01-01

This review presents a comprehensive illustrated overview of the wide variety of cystic lesions around the knee. The aetiology, clinical presentation, MRI appearances and differential diagnosis are discussed. Bursae include those related to the patella as well as pes anserine, tibial collateral ligament, semimembranosus-tibial collateral ligament, iliotibial and fibular collateral ligament-biceps femoris. The anatomical extension, imaging features and clinical significance of meniscal cysts are illustrated. Review of ganglia includes intra-articular, extra-articular, intraosseous and periosteal ganglia, highlighting imaging findings and differential diagnoses. The relationship between proximal tibiofibular joint cysts and intraneural peroneal nerve ganglia is discussed. Intraosseous cystic lesions, including insertional and degenerative cysts, as well as lesions mimicking cysts of the knee are described and illustrated. Knowledge of the location, characteristic appearance and distinguishing features of cystic masses around the knee as well as potential imaging pitfalls such as normal anatomical recesses and atypical cyst contents on MR imaging aids in allowing a specific diagnosis to be made. This will prevent unnecessary additional investigations and determine whether intra-articular surgery or conservative management is appropriate. (orig.)

Knee motion variability in patients with knee osteoarthritis: the effect of self-reported instability

Science.gov (United States)

Gustafson, Jonathan A.; Robinson, Megan E.; Fitzgerald, G. Kelley; Tashman, Scott; Farrokhi, Shawn

2015-01-01

Background Knee osteoarthritis has been previously associated with a stereotypical knee-stiffening gait pattern and reduced knee joint motion variability due to increased antagonist muscle co-contractions and smaller utilized arc of motion during gait. However, episodic self-reported instability may be a sign of excessive motion variability for a large subgroup of patients with knee osteoarthritis. The objective of this work was to evaluate the differences in knee joint motion variability during gait in patients with knee osteoarthritis with and without self-reported instability compared to a control group of older adults with asymptomatic knees. Methods Forty-three subjects, 8 with knee osteoarthritis but no reports of instability (stable), 11 with knee osteoarthritis and self-reported instability (unstable), and 24 without knee osteoarthritis or instability (control) underwent Dynamic Stereo X-ray analysis during a decline gait task on a treadmill. Knee motion variability was assessed using parametric phase plots during the loading response phase of decline gait. Findings The stable group demonstrated decreased sagittal-plane motion variability compared to the control group (p=0.04), while the unstable group demonstrated increased sagittal-plane motion variability compared to the control (p=0.003) and stable groups (pknee motion variability in patients with knee osteoarthritis without self-reported instability supports previous research. However, presence of self-reported instability is associated with increased knee motion variability in patients with knee osteoarthritis and warrants further investigation. PMID:25796536

Knee osteoarthritis in traumatic knee symptoms in general practice: 6-year cohort study

NARCIS (Netherlands)

M. Kastelein (Marlous); P.A.J. Luijsterburg (Pim); I.M. Koster (Ingrid); J.A.N. Verhaar (Jan); D. Vroegindeweij (Dammis); S.M. Bierma-Zeinstra (Sita); E.H.G. Oei (Edwin)

2016-01-01

textabstractAim: To identify degenerative knee abnormalities using MRI and radiography 6 years after knee trauma, their relation with persistent knee symptoms and baseline prognostic factors. Methods: Adults (18–65 years) with incident traumatic knee symptoms visiting their

The Validity of a New Low-Dose Stereoradiography System to Perform 2D and 3D Knee Prosthetic Alignment Measurements.

Directory of Open Access Journals (Sweden)

Marrigje F Meijer

Full Text Available The EOS stereoradiography system has shown to provide reliable varus/valgus (VV measurements of the lower limb in 2D (VV2D and 3D (VV3D after total knee arthroplasty (TKA. Validity of these measurements has not been investigated yet, therefore the purpose of this study was to determine validity of EOS VV2D and VV3D.EOS images were made of a lower limb phantom containing a knee prosthesis, while varying VV angle from 15° varus to 15° valgus and flexion angle from 0° to 20°, and changing rotation from 20° internal to 20° external rotation. Differences between the actual VV position of the lower limb phantom and its position as measured on EOS 2D and 3D images were investigated.Rotation, flexion or VV angle alone had no major impact on VV2D or VV3D. Combination of VV angle and rotation with full extension did not show major differences in VV2D measurements either. Combination of flexion and rotation with a neutral VV angle showed variation of up to 7.4° for VV2D; maximum variation for VV3D was only 1.5°. A combination of the three variables showed an even greater distortion of VV2D, while VV3D stayed relatively constant. Maximum measurement difference between preset VV angle and VV2D was 9.8°, while the difference with VV3D was only 1.9°. The largest differences between the preset VV angle and VV2D were found when installing the leg in extreme angles, for example 15° valgus, 20° flexion and 20° internal rotation.After TKA, EOS VV3D were more valid than VV2D, indicating that 3D measurements compensate for malpositioning during acquisition. Caution is warranted when measuring VV angle on a conventional radiograph of a knee with a flexion contracture, varus or valgus angle and/or rotation of the knee joint during acquisition.

The effect of dynamic knee-extension exercise on patellar tendon and quadriceps femoris muscle glucose uptake in humans studied by positron emission tomography

DEFF Research Database (Denmark)

Kalliokoski, Kari K; Langberg, Henning; Ryberg, Ann Kathrine

2005-01-01

Both tendon and peritendinous tissue show evidence of metabolic activity, but the effect of acute exercise on substrate turnover is unknown. We therefore examined the influence of acute exercise on glucose uptake in the patellar and quadriceps tendons during dynamic exercise in humans. Glucose...... that tendon glucose uptake is increased during exercise. However, the increase in tendon glucose uptake is less pronounced than in muscle and the increases are uncorrelated. Thus tendon glucose uptake is likely to be regulated by mechanisms independently of those regulating skeletal muscle glucose uptake....... uptake was measured in five healthy men in the patellar and quadriceps tendons and the quadriceps femoris muscle at rest and during dynamic knee-extension exercise (25 W) using positron emission tomography and [18F]-2-fluoro-2-deoxy-D-glucose ([18F]FDG). Glucose uptake index was calculated by dividing...

Benefits of sagittal-oblique MRI reconstruction of anterior cruciate ligament of the knee

International Nuclear Information System (INIS)

Nenezić, D.

2015-01-01

Full text: MRI examination of the anterior cruciate ligament (ACL) of the knee gives valuable information for conventional, physiatrist and/or arthroscopic microinvasiv treatment. three planar MRI examination and 3D reconstructions are highly precise in the analysis of the intra and periarticular structures, with exceptions of anterior cruciate ligament. Direct contact with the roof of the intercondilar fossa (in the full extension during the examination) and its specific orientation makes visualization of ACL diagnostically problematic. In a one year period precise protocol for MRI visualization of ACL was tested and applied as “Sagittal Oblique MRI Reconstruction”. In short, it has been Angled biplanar reconstruction in the parasagital and paratransversal planes (patientrelated and arbitrary selected in full extension), on T2, 2mm slice and 0,2 mm gap. 153 MRI examinations of the patients with lesions of the ACL were included in the study in the Clinical Center of Montenegro during 2005 year. Beside standard Knee MRI protocol all patients had the Sagittal Oblique MRI reconstruction of ACL and the Flexion MRI examination, to compare with. The Sagittal Oblique MRI reconstruction of ACL it is adapted to the concrete morphology of the patients ACL and it does not depend of the volume of the examined knee. In comparison with the Standard Knee MRI protocol and with the Flexion MRI examination, the Sagittal Oblique MRI reconstruction of ACL takes less time to perform, and the ligament is shown in fool length at three to five slices, which is more than with the both compared protocols. Sagittal Oblique MRI Reconstruction of ACL is therefore patient dependable, orientated in shape of concrete ligament of the patient’s knee. In combination with age, occupation, physical activity and level of patients while to contribute in healing process, the Sagittal Oblique MRI reconstruction of ACL contribute to scholastic approach, as highest benefit to patients with

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

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Ferris Daniel P

2009-06-01

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

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

Science.gov (United States)

Sawicki, Gregory S; Ferris, Daniel P

2009-01-01

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

Three-dimensional dynamic analysis of knee joint during gait in medial knee osteoarthritis using loading axis of knee.

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Nishino, Katsutoshi; Omori, Go; Koga, Yoshio; Kobayashi, Koichi; Sakamoto, Makoto; Tanabe, Yuji; Tanaka, Masaei; Arakawa, Masaaki

2015-07-01

We recently developed a new method for three-dimensional evaluation of mechanical factors affecting knee joint in order to help identify factors that contribute to the progression of knee osteoarthritis (KOA). This study aimed to verify the clinical validity of our method by evaluating knee joint dynamics during gait. Subjects were 41 individuals (14 normal knees; 8 mild KOAs; 19 severe KOAs). The positions of skin markers attached to the body were captured during gait, and bi-planar X-ray images of the lower extremities were obtained in standing position. The positional relationship between the markers and femorotibial bones was determined from the X-ray images. Combining this relationship with gait capture allowed for the estimation of relative movement between femorotibial bones. We also calculated the point of intersection of loading axis of knee on the tibial proximal surface (LAK point) to analyze knee joint dynamics. Knee flexion range in subjects with severe KOA during gait was significantly smaller than that in those with normal knees (p=0.011), and knee adduction in those with severe KOA was significantly larger than in those with mild KOA (p<0.000). LAK point was locally loaded on the medial compartment of the tibial surface as KOA progressed, with LAK point of subjects with severe KOA rapidly shifting medially during loading response. Local loading and medial shear force were applied to the tibial surface during stance phase as medial KOA progressed. Our findings suggest that our method is useful for the quantitative evaluation of mechanical factors that affect KOA progression. Copyright © 2015 Elsevier B.V. All rights reserved.

The importance of bony impingement in restricting flexion after total knee arthroplasty: computer simulation model with clinical correlation.

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Mizu-Uchi, Hideki; Colwell, Clifford W; Fukagawa, Shingo; Matsuda, Shuichi; Iwamoto, Yukihide; D'Lima, Darryl D

2012-10-01

We constructed patient-specific models from computed tomography data after total knee arthroplasty to predict knee flexion based on implant-bone impingement. The maximum flexion before impingement between the femur and the tibial insert was computed using a musculoskeletal modeling program (KneeSIM; LifeModeler, Inc, San Clemente, California) during a weight-bearing deep knee bend. Postoperative flexion was measured in a clinical cohort of 21 knees (low-flex group: 6 knees with 125° of flexion at 2 years). Average predicted flexion angles were within 2° of clinical measurements for the high-flex group. In the low-flex group, 4 cases had impingement involving the bone cut at the posterior condyle, and the average predicted knee flexion was 102° compared with 93° measured clinically. These results indicate that the level of the distal femoral resection should be carefully planned and that exposed bone proximal to the tips of the posterior condyles of the femoral component should be removed if there is risk of impingement. Copyright © 2012 Elsevier Inc. All rights reserved.

Association of Obesity, Parity, and History of Knee Injury with Knee Osteoarthritis in Female

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Ade Triyadi

2015-12-01

Full Text Available Background: Osteoarthritis is the most joint disorder among elderly. There are a lot of risk factors of knee osteoarthritis. Obesity and high frequent of parity can increase the load on knee joint. Knee injury also decreases the stability of knee joint on bearing body load. This study was conducted to observe the association of obesity, parity ≥3 times and history of knee injury with the occurrence of knee osteoarthritis in female aged >50 years old. Methods: Case control design was chosen in this study. Female patients with age >50 years were recruited by consecutive sampling from rheumatology clinic at Dr. Hasan Sadikin General Hospital Bandung. Data were collected from August to September 2013. Minimal sample size was 60 samples calculated by rule of thumb formula. Obesity was measured by body mass index (BMI. Parity and history of knee injury were assessed by questionnaire. Those variables were analyzed by logistic regression method. Result: Obesity did not associate with knee osteoarthritis in this study, p=0.549 (odd ratio (OR 1.32, 95% confidence interval (CI 0.52–3.32. Parity was associated with knee osteoarthritis in this study p=0.001 (OR 4.7, 95% CI 1.89–11.68. History of knee injury was associated with knee osteoarthritis in this study, p=0.001 (OR 6.19, 95% CI 2.01–18.99. Conclusions: Parity ≥3 times and history of knee injury were associated with the occurrence of knee osteoarthritis. Obesity was not associated with the occurrence of knee osteoarthritis.

Do Psychosocial Factors Predict Muscle Strength, Pain, or Physical Performance in Patients With Knee Osteoarthritis?

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Baert, Isabel A C; Meeus, Mira; Mahmoudian, Armaghan; Luyten, Frank P; Nijs, Jo; Verschueren, Sabine M P

2017-09-01

The aim of this study was to examine the relationship of psychosocial factors, namely, pain catastrophizing, kinesiophobia, and maladaptive coping strategies, with muscle strength, pain, and physical performance in patients with knee osteoarthritis (OA)-related symptoms. A total of 109 women (64 with knee OA-related symptoms) with a mean age of 65.4 years (49-81 years) were recruited for this study. Psychosocial factors were quantified by the Pain Catastrophizing Scale, Tampa Scale for Kinesiophobia, and Pain Coping Inventory. Clinical features were assessed using isometric and isokinetic knee muscle strength measurements, visual analog scale, Western Ontario and McMaster Universities Osteoarthritis Index, and functional tests. Associations were examined using correlation and regression analysis. In knee OA patients, pain catastrophizing, kinesiophobia, and coping strategy explained a significant proportion of the variability in isometric knee extension and flexion strength (6.3%-9.2%), accounting for more overall variability than some demographic and medical status variables combined. Psychosocial factors were not significant independent predictors of isokinetic strength, knee pain, or physical performance. In understanding clinical features related to knee OA, such as muscle weakness, pain catastrophizing, kinesiophobia, and coping strategy might offer something additional beyond what might be explained by traditional factors, underscoring the importance of a biopsychosocial approach in knee OA management. Further research on individual patient characteristics that mediate the effects of psychosocial factors is, however, required in order to create opportunities for more targeted, personalized treatment for knee OA.

Knee arthrodesis – ultima ratio for the treatment of the infected knee

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Tiemann, Andreas H. H.

2013-04-01

Full Text Available The irretrievable destruction of the knee due to trauma, tumor or infection is the indication for knee arthrodesis. The main reason for knee arthrodesis in terms of infection ist the infected total knee arthroplasty. Central problem is the definition of the term “irretrievable”. It is based on the subjective opinion of the attending physician and depends on his expert knowledge of this specific entity. The preservation of a functioning extremity is the main goal.This article shows the typical indications and contraindications for knee arthrodesis following septic knee diseases. In addition it gives insight into the biomechanical and technical considerations to be kept in mind. Finally the postoperative care and outcome of different techniques are analysed.

Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling

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Shen, Guangping; Zhang, Songning; Bennett, Hunter J.; Martin, James C.; Crouter, Scott E.; Fitzhugh, Eugene C.

2018-01-01

Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling. Key points Varus or valgus alignment did not cause increased frontal-plane knee joint loading, suggesting stationary cycling is a safe exercise. This study supports that using a toe clip did not lead to abnormal frontal-plane knee loading during stationary cycling. Two different knee frontal plane loading patterns, knee abduction and adduction moment, were observed during stationary cycling, which are likely affected by

Evaluation and management of knee pain in young athletes: overuse injuries of the knee

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Patel, Dilip R.; Villalobos, Ana

2017-01-01

Recurrent or chronic activity related knee pain is common in young athletes. Numerous intrinsic conditions affecting the knee can cause such pain. In addition, knee pain can be referred pain from low back, hip or pelvic pathology. The most common cause of knee pain in young athletes is patellofemoral pain syndrome, or more appropriately termed idiopathic anterior knee pain. Although, numerous anatomical and biomechanical factors have been postulated to contribute the knee pain in young athlet...

Multiple half-second acquisition method of the moving knee joint. Kinematic MR imaging of the anterior cruciate ligament

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Niitsu, Mamoru; Ikeda, Kotaroh; Fukubayashi, Tohru; Echigo, Junko; Itai, Yuji [Tsukuba Univ., Ibaraki (Japan). Inst. of Clinical Medicine

1996-10-01

The objective of this study was to delineate the moving anterior cruciate ligament (ACL) with multiple rapid magnetic resonance (MR) imaging. Rapid gradient echo MR images with an one-shot acquisition time of a half-second were accomplished by short repetition time and phase encoding reduction. Using a mobile knee brace and a flexible surface coil, half-second acquisitions were sequentially acquired during active, constant knee movement. Sixteen knees with intact ACLs and 27 knees with arthroscopically proven ACL tears were examined. Normal ACLs were identified as moving linear low-intensities. The ligaments were readily identified as straight or minimally curved structures when the knee was in semi-flexion compared to the knee extension. Torn ACLs were demonstrated as moving fragments or an amorphous configuration. Intermittent appearances of joint fluid interrupted the ligamentous continuities. Compared to the static images, no significant superiority of the kinematic imaging was found in diagnosis of ACL tears. However, this instant kinematic imaging is feasible with a standard MR system and can provide morphological information for functional analysis of the knee. (author)

A Soft-Inflatable Exosuit for Knee Rehabilitation: Assisting Swing Phase During Walking

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Saivimal Sridar

2018-05-01

Full Text Available In this paper, we present a soft-inflatable exosuit to assist knee extension during gait training for stroke rehabilitation. The soft exosuit is designed to provide 25% of the knee moment required during the swing phase of the gait cycle and is integrated with inertial measurement units (IMUs and smart shoe insole sensors to improve gait phase detection and controller design. The stiffness of the knee joint during level walking is computed using inverse dynamics. The soft-inflatable actuators, with an I cross-section, are mechanically characterized at varying angles to enable generation of the required stiffness outputs. A linear relation between the inflatable actuator stiffness and internal pressure as a function of the knee angle is obtained, and a two-layer stiffness controller is implemented to assist the knee joint by providing appropriate stiffness during the swing phase. Finally, to evaluate the ability of the exosuit to assist in swing motion, surface-electromyography (sEMG sensors are placed on the three muscle groups of the quadriceps and two groups of the hamstrings, on three healthy participants. A reduction in muscle activity of the rectus femoris, vastus lateralis, and vastus medialis is observed, which demonstrates feasibility of operation and potential future usage of the soft inflatable exosuit by impaired users.

Total knee arthroplasty

DEFF Research Database (Denmark)

Schrøder, Henrik M.; Petersen, Michael M.

2016-01-01

Total knee arthroplasty (TKA) is a successful treatment of the osteoarthritic knee, which has increased dramatically over the last 30 years. The indication is a painful osteoarthritic knee with relevant radiographic findings and failure of conservative measures like painkillers and exercise...... surgeon seems to positively influence the rate of surgical complications and implant survival. The painful TKA knee should be thoroughly evaluated, but not revised except if a relevant indication can be established. The most frequent indications for revision are: aseptic loosening, instability, infection...

Increased knee valgus alignment and moment during single-leg landing after overhead stroke as a potential risk factor of anterior cruciate ligament injury in badminton.

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Kimura, Yuka; Ishibashi, Yasuyuki; Tsuda, Eiichi; Yamamoto, Yuji; Hayashi, Yoshimitsu; Sato, Shuichi

2012-03-01

In badminton, knees opposite to the racket-hand side received anterior cruciate ligament (ACL) injuries during single-leg landing after overhead stroke. Most of them occurred in the backhand-side of the rear court. Comparing lower limb biomechanics during single-leg landing after overhead stroke between the forehand-side and backhand-side court may help explain the different injury rates depending on court position. The knee kinematics and kinetics during single-leg landing after overhead stroke following back-stepping were different between the forehand-side and backhand-side court. Controlled laboratory study. Hip, knee and ankle joint kinematic and knee kinetic data were collected for 17 right-handed female college badminton players using a 3-dimensional motion analysis system. Subjects performed single-left-legged landing after an overhead stroke following left and right back-stepping. The kinematic and kinetic data of the left lower extremities during landing were measured and compared between left and right back-steps. Hip flexion and abduction and knee valgus at the initial contact, hip and knee flexion and knee valgus at the maximum knee flexion and the maximum knee valgus moment were significantly larger for the left back-step than the right back-step (p<0.05). Significant differences in joint kinematics and kinetics of the lower extremity during single-leg landing after overhead stroke were observed between different back-step directions. Increased knee valgus angle and moment following back-stepping to the backhand-side might be related to the higher incidence of ACL injury during single-leg landing after overhead stroke.

EFFECTIVENESS OF PNF STRETCHING VERSUS STATIC STRETCHING ON PAIN AND HAMSTRING FLEXIBILITY FOLLOWING MOIST HEAT IN INDIVIDUALS WITH KNEE OSTEOARTHRITIS

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Meena .V

2016-10-01

Full Text Available Background: Osteoarthritis (OA is a degenerative joint disease and one of the major public health problem that causesfunctional impairment and reduced quality of life. To compare the effectiveness of PNF Hold relax stretching versus Static stretching on pain and flexibility of hamstring following moist heat in individuals with knee osteoarthritis. Hamstring tightness is the major problem in knee osteoarthritis individuals. Therefore the need of study is comparing the effectiveness of PNF Hold relax stretching versus static stretching on pain and flexibility of hamstrings following moist heat in knee osteoarthritis participants. Determining the effects of PNF Hold relax stretching versus Static stretching along with moist heat on pain and hamstring flexibility by VAS and Active knee extension range of motion in knee osteoarthritis individuals. Methods: 30 subjects with symptoms of knee osteoarthritis were randomly distributed into 2 groups 15 in each group. PNF Hold relax stretching along with moist heat is compared to Static stretching along with moist heat. Pain was measured by Visual Analogue Scale (VAS and hamstring flexibility by Active knee Extension Range of Motion (AKEROM by universal goniometer. Measurements are taken pre and post intervention. Results: The results indicated PNF Hold relax stretching along with moist heat showed a statistically significant improvement in pain (p<0.05 and improvement in hamstring flexibility (p<0.05 when compared to Static stretching along with moist heat. Conclusion: Subjects with PNF Hold relax stretching along with moist heat showed significant improvement in pain reduction and improving hamstring flexibility than Static stretching along with moist heat.

Runner's Knee

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... require a lot of knee bending, such as biking, jumping, or skiing. Runner's knee happens when the ... is out of alignment, activities like running or biking can wear down the cartilage of the kneecap ( ...

Reciprocal activation of gastrocnemius and soleus motor units is associated with fascicle length change during knee flexion.

Science.gov (United States)

Lauber, Benedikt; Lichtwark, Glen A; Cresswell, Andrew G

2014-06-01

While medial gastrocnemius (MG) and soleus (SOL) are considered synergists, they are anatomically exclusive in that SOL crosses only the ankle, while MG crosses both the knee and ankle. Due to the force-length properties of both active and passive structures, activation of SOL and MG must be constantly regulated to provide the required joint torques for any planned movement. As such, the aim of this study was to investigate the neural regulation of MG and SOL when independently changing their length by changing only the knee joint angle, thus exclusively altering the length of MG fibers. MG and SOL motor units (MU) were recorded intramuscularly along with ultrasound imaging of MG and SOL fascicle lengths, while moving the knee through 60° of rotation and maintaining a low level of voluntary plantar flexor torque. The results showed a reciprocal activation of MG and SOL as the knee was moved into flexion and extension. A clear reduction in MG MU firing rates occurred as the knee was flexed (MG fascicles shortening), with de-recruitment of most MG MU occurring at close to full knee flexion. A concomitant increase in SOL MU activity was observed while no change in the length of its fascicles was found. The opposite effects were found when the knee was moved into extension. A strong correlation (ICC = 0.78) was found between the fascicle length at which MG MUs were de-recruited and subsequently re-recruited. This was stronger than the relationship of de-recruitment and re-recruitment with knee angle (ICC = 0.52), indicating that in this instance, muscle fascicle length rather than joint angle is more influential in regulating MG recruitment. Such a reciprocal arrangement like the one presented here for SOL and MG is essential for human voluntary movements such as walking or cycling. © 2014 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society.

Bilateral differences in peak force, power, and maximum plie depth during multiple grande jetes

NARCIS (Netherlands)

Wyon, M.; Harris, J.; Brown, D.D.; Clark, F.

2013-01-01

A lateral bias has been previously reported in dance training. The aim of this study was to investigate whether there are any bilateral differences in peak forces, power, and maximum knee flexion during a sequence of three grand jetes and how they relate to leg dominance. A randomised observational

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

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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

Quadriceps Tendon Rupture and Contralateral Patella Tendon Avulsion Post Primary Bilateral Total Knee Arthroplasty: A Case Report

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Gaurav Sharma

2016-07-01

Full Text Available Background: Extensor mechanism failure secondary to knee replacement could be due to tibial tubercle avulsion, Patellar tendon rupture, patellar fracture or quadriceps tendon rupture. An incidence of Patella tendon rupture of 0.17% and Quadriceps tendon rupture of around 0.1% has been reported after Total knee arthroplasty. These are considered a devastating complication that substantially affects the clinical results and are challenging situations to treat with surgery being the mainstay of the treatment. Case Description: We report here an interesting case of a patellar tendon rupture of one knee and Quadriceps tendon rupture of the contralateral knee following simultaneous bilateral knee replacement in a case of inflammatory arthritis patient. End to end repair for Quadriceps tear and augmentation with Autologous Hamstring tendon graft was done for Patella tendon rupture. OUTCOME: Patient was followed up for a period of 1 year and there was no Extension lag with a flexion of 100 degrees in both the knees. DISCUSSION: The key learning points and important aspects of diagnosing these injuries early and the management techniques are described in this unique case of bilateral extensor mechanism disruption following knee replacements.

Musculoskeletal MR: knee

International Nuclear Information System (INIS)

Staebler, A.; Glaser, C.; Reiser, M.

2000-01-01

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.)

Prevalent knee pain and sport

DEFF Research Database (Denmark)

Hahn, Thomas; Foldspang, Anders

1998-01-01

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

Single-Leg Hop Test Performance and Isokinetic Knee Strength After Anterior Cruciate Ligament Reconstruction in Athletes.

Science.gov (United States)

Sueyoshi, Ted; Nakahata, Akihiro; Emoto, Gen; Yuasa, Tomoki

2017-11-01

Isokinetic strength and hop tests are commonly used to assess athletes' readiness to return to sport after knee surgery. The purpose of this study was to investigate the results of single-leg hop and isokinetic knee strength testing in athletes who underwent anterior cruciate ligament reconstruction (ACLR) upon returning to sport participation as well as to study the correlation between these 2 test batteries. The secondary purpose was to compare the test results by graft type (patellar tendon or hamstring). It was hypothesized that there would be no statistically significant limb difference in either isokinetic knee strength or single-leg hop tests, that there would be a moderate to strong correlation between the 2 test batteries, and that there would be no significant difference between graft types. Cross-sectional study; Level of evidence, 3. Twenty-nine high school and collegiate athletes who underwent ACLR participated in this study. At the time of return to full sport participation, a series of hop tests and knee extension/flexion isokinetic strength measurements were conducted. The results were analyzed using analysis of variance and Pearson correlation ( r ). The timed 6-m hop test was the only hop test that showed a significant difference between the involved and uninvolved limbs (2.3 and 2.2 seconds, respectively; P = .02). A significant difference between limbs in knee strength was found for flexion peak torque/body weight at 180 deg/s ( P = .03), flexion total work/body weight at 180 deg/s ( P = .04), and flexion peak torque/body weight at 300 deg/s ( P = .03). The strongest correlation between the hop tests and knee strength was found between the total distance of the hop tests and flexion total work/body weight at 300 deg/s ( r = 0.69) and between the timed 6-m hop test and flexion peak torque/body weight at 300 deg/s ( r = -0.54). There was no statistically significant difference in hop test performance or isokinetic knee strength between graft types

Effects of Knee Alignments and Toe Clip on Frontal Plane Knee Biomechanics in Cycling.

Science.gov (United States)

Shen, Guangping; Zhang, Songning; Bennett, Hunter J; Martin, James C; Crouter, Scott E; Fitzhugh, Eugene C

2018-06-01

Effects of knee alignment on the internal knee abduction moment (KAM) in walking have been widely studied. The KAM is closely associated with the development of medial knee osteoarthritis. Despite the importance of knee alignment, no studies have explored its effects on knee frontal plane biomechanics during stationary cycling. The purpose of this study was to examine the effects of knee alignment and use of a toe clip on the knee frontal plane biomechanics during stationary cycling. A total of 32 participants (11 varus, 11 neutral, and 10 valgus alignment) performed five trials in each of six cycling conditions: pedaling at 80 rpm and 0.5 kg (40 Watts), 1.0 kg (78 Watts), and 1.5 kg (117 Watts) with and without a toe clip. A motion analysis system and a customized instrumented pedal were used to collect 3D kinematic and kinetic data. A 3 × 2 × 3 (group × toe clip × workload) mixed design ANOVA was used for statistical analysis (p < 0.05). There were two different knee frontal plane loading patterns, internal abduction and adduction moment, which were affected by knee alignment type. The knee adduction angle was 12.2° greater in the varus group compared to the valgus group (p = 0.001), yet no difference was found for KAM among groups. Wearing a toe clip increased the knee adduction angle by 0.95º (p = 0.005). The findings of this study indicate that stationary cycling may be a safe exercise prescription for people with knee malalignments. In addition, using a toe clip may not have any negative effects on knee joints during stationary cycling.

Association between knee alignment and knee pain in patients surgically treated for medial knee osteoarthritis by high tibial osteotomy. A one year follow-up study

DEFF Research Database (Denmark)

W-Dahl, Annette; Toksvig-Larsen, Sören; Roos, Ewa

2009-01-01

on for knee OA by high tibial osteotomy. METHODS: 182 patients (68% men) mean age 53 years (34 - 69) with varus alignment having tibial osteotomy by the hemicallotasis technique for medial knee OA were consecutively included. Knee alignment was assessed by the Hip-Knee-Ankle (HKA) angle from radiographs...... including the hip and ankle joints. Knee pain was measured by the subscale pain (0 - 100, worst to best scale) of the Knee injury and Osteoarthritis Outcome Score (KOOS) preoperatively and at one year follow-up. To estimate the association between knee alignment and knee pain multivariate regression...... with every degree of HKA angle, adjusted analysis 0.3 points (95% CI -1.3 - 0.6).The mean postoperative knee alignment was 184 degrees (171 - 185). The mean change in knee alignment was 13 degrees (0 - 30). The mean change in KOOS pain was 32 (-16 - 83). There was neither any association between change...

Body mass index affects knee joint mechanics during gait differently with and without moderate knee osteoarthritis.

Science.gov (United States)

Harding, Graeme T; Hubley-Kozey, Cheryl L; Dunbar, Michael J; Stanish, William D; Astephen Wilson, Janie L

2012-11-01

Obesity is a highly cited risk factor for knee osteoarthritis (OA), but its role in knee OA pathogenesis and progression is not as clear. Excess weight may contribute to an increased mechanical burden and altered dynamic movement and loading patterns at the knee. The objective of this study was to examine the interacting role of moderate knee OA disease presence and obesity on knee joint mechanics during gait. Gait analysis was performed on 104 asymptomatic and 140 individuals with moderate knee OA. Each subject group was divided into three body mass categories based on body mass index (BMI): healthy weight (BMI30). Three-dimensional knee joint angles and net external knee joint moments were calculated and waveform principal component analysis (PCA) was applied to extract major patterns of variability from each. PC scores for major patterns were compared between groups using a two-factor ANOVA. Significant BMI main effects were found in the pattern of the knee adduction moment, the knee flexion moment, and the knee rotation moment during gait. Two interaction effects between moderate OA disease presence and BMI were also found that described different changes in the knee flexion moment and the knee flexion angle with increased BMI with and without knee OA. Our results suggest that increased BMI is associated with different changes in biomechanical patterns of the knee joint during gait depending on the presence of moderate knee OA. Copyright © 2012 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

Zahra Bassiri

2015-01-01

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

Autologous blood transfusion in total knee replacement surgery.

Science.gov (United States)

Sarkanović, Mirka Lukić; Gvozdenović, Ljiljana; Savić, Dragan; Ilić, Miroslav P; Jovanović, Gordana

2013-03-01

Total knee replacement (TKR) surgery is one of the most frequent and the most extensive procedures in orthopedic surgery, accompanied with some serious complications. Perioperative blood loss is one of the most serious losses, so it is vital to recognize and treat such losses properly. Autologous blood transfusion is the only true alternative for the allogeneic blood. The aim of this study was to to examine if autologous blood transfusion reduces usage of allogenic blood in total knee replacement surgery, as well as to examine possible effect of autologous blood transfusion on postoperative complications, recovery and hospital stay of patients after total knee replacement surgery. During the controlled, prospective, randomised study we compared two groups of patients (n = 112) with total prosthesis implanted in their knee. The group I consisted of the patients who received the transfusion of other people's (allogeneic) blood (n = 57) and the group II of the patients whose blood was collected postoperatively and then given them [their own (autologous) blood] (n = 55). The transfusion trigger for both groups was hemoglobin level of 85 g/L. In the group of patients whose blood was collected perioperatively only 9 (0.9%) of the patients received transfusion of allogeneic blood, as opposed to the control group in which 98.24% of the patients received the transfusion of allogeneic blood (p blood was collected stayed in hospital for 6.18 days, while the patients of the control group stayed 7.67 days (p blood transfusion is a very effective method for reducing consumption of allogenic blood and thus, indirectly for reducing all complications related to allogenic blood transfusion. There is also a positive influence on postoperative recovery after total knee replacement surgery due to the reduction of hospital stay, and indirectly on the reduction of hospital costs.

Femoral Component External Rotation Affects Knee Biomechanics: A Computational Model of Posterior-stabilized TKA.

Science.gov (United States)

Kia, Mohammad; Wright, Timothy M; Cross, Michael B; Mayman, David J; Pearle, Andrew D; Sculco, Peter K; Westrich, Geoffrey H; Imhauser, Carl W

2018-01-01

The correct amount of external rotation of the femoral component during TKA is controversial because the resulting changes in biomechanical knee function associated with varying degrees of femoral component rotation are not well understood. We addressed this question using a computational model, which allowed us to isolate the biomechanical impact of geometric factors including bony shapes, location of ligament insertions, and implant size across three different knees after posterior-stabilized (PS) TKA. Using a computational model of the tibiofemoral joint, we asked: (1) Does external rotation unload the medial collateral ligament (MCL) and what is the effect on lateral collateral ligament tension? (2) How does external rotation alter tibiofemoral contact loads and kinematics? (3) Does 3° external rotation relative to the posterior condylar axis align the component to the surgical transepicondylar axis (sTEA) and what anatomic factors of the femoral condyle explain variations in maximum MCL tension among knees? We incorporated a PS TKA into a previously developed computational knee model applied to three neutrally aligned, nonarthritic, male cadaveric knees. The computational knee model was previously shown to corroborate coupled motions and ligament loading patterns of the native knee through a range of flexion. Implant geometries were virtually installed using hip-to-ankle CT scans through measured resection and anterior referencing surgical techniques. Collateral ligament properties were standardized across each knee model by defining stiffness and slack lengths based on the healthy population. The femoral component was externally rotated from 0° to 9° relative to the posterior condylar axis in 3° increments. At each increment, the knee was flexed under 500 N compression from 0° to 90° simulating an intraoperative examination. The computational model predicted collateral ligament forces, compartmental contact forces, and tibiofemoral internal/external and

Maximum non-extensive entropy block bootstrap for non-stationary processes

Czech Academy of Sciences Publication Activity Database

Bergamelli, M.; Novotný, Jan; Urga, G.

2015-01-01

Roč. 91, 1/2 (2015), s. 115-139 ISSN 0001-771X R&D Projects: GA ČR(CZ) GA14-27047S Institutional support: RVO:67985998 Keywords : maximum entropy * bootstrap * Monte Carlo simulations Subject RIV: AH - Economics

The reliabilty of isokinetic strength measurement

OpenAIRE

Kadlec, Miroslav

2011-01-01

Title: Reliability of isometric and isokinetic strength testing in the knee flexion and extension Objectives: To compare the reliability of isometric and isokinetic testing of the knee strength in flexion and extension Methods: I used intraclass correlation coefficient and Pearson's correlation coefficient. Results: I have discovered that the reliability measured on isokinetic and isometric dynamometer is high. Furthermore the reliability of the maximum strength measurement was higher with-us...

A system for the registration of arthroscopic images to magnetic resonance images of the knee: for improved virtual knee arthroscopy

Science.gov (United States)

Hu, Chengliang; Amati, Giancarlo; Gullick, Nicola; Oakley, Stephen; Hurmusiadis, Vassilios; Schaeffter, Tobias; Penney, Graeme; Rhode, Kawal

2009-02-01

Knee arthroscopy is a minimally invasive procedure that is routinely carried out for the diagnosis and treatment of pathologies of the knee joint. A high level of expertise is required to carry out this procedure and therefore the clinical training is extensive. There are several reasons for this that include the small field of view seen by the arthroscope and the high degree of distortion in the video images. Several virtual arthroscopy simulators have been proposed to augment the learning process. One of the limitations of these simulators is the generic models that are used. We propose to develop a new virtual arthroscopy simulator that will allow the use of pathology-specific models with an increased level of photo-realism. In order to generate these models we propose to use registered magnetic resonance images (MRI) and arthroscopic video images collected from patients with a variety of knee pathologies. We present a method to perform this registration based on the use of a combined X-ray and MR imaging system (XMR). In order to validate our technique we carried out MR imaging and arthroscopy of a custom-made acrylic phantom in the XMR environment. The registration between the two modalities was computed using a combination of XMR and camera calibration, and optical tracking. Both two-dimensional (2D) and three-dimensional (3D) registration errors were computed and shown to be approximately 0.8 and 3 mm, respectively. Further to this, we qualitatively tested our approach using a more realistic plastic knee model that is used for the arthroscopy training.

Modification of Knee Flexion Angle Has Patient-Specific Effects on Anterior Cruciate Ligament Injury Risk Factors During Jump Landing.

Science.gov (United States)

Favre, Julien; Clancy, Caitlin; Dowling, Ariel V; Andriacchi, Thomas P

2016-06-01

The incidence of anterior cruciate ligament (ACL) injuries may be decreased through the use of intervention programs that focus on increasing the knee flexion angle during jump landing, which decreases strain on the ACL. To investigate whether intervention training designed to change the knee flexion angle during landing causes secondary changes in other known measures associated with the risk of ACL injuries and to examine the time points when these secondary measures change. Controlled laboratory study. A total of 39 healthy recreational athletes performed a volleyball block jump task in an instrumented gait laboratory. The participants first completed the jumps without any modification to their normal landing technique. They were then given oral instruction to land softly and to increase their knee flexion angle during landing. Lower body kinematics and kinetics were measured before and after the modification using an optoelectronic motion capture system. The knee flexion angle after the modification significantly increased from 11.2° to 15.2° at initial contact and from 67.8° to 100.7° at maximum flexion, and the time between initial contact and maximum flexion increased from 177.4 to 399.4 milliseconds. The flexion modification produced a substantial reduction in vertical ground-reaction force (243.1 to 187.8 %BW) with a concomitant reduction in the maximum flexion moment. Interestingly, the flexion modification only affected the abduction angle and abduction moment for the group of participants that landed in an initial adducted position before the modification and had no significant effect on the group that landed in an abducted position. Increasing the knee flexion angle during jump landing may be an effective intervention to improve knee biomechanical risk factors associated with an ACL injury. However, the fact that the flexion modification only influenced critical risk factors (the abduction angle and abduction moment) in participants who initially

Associations of knee extensor strength and standing balance with physical function in knee osteoarthritis.

Science.gov (United States)

Pua, Yong-Hao; Liang, Zhiqi; Ong, Peck-Hoon; Bryant, Adam L; Lo, Ngai-Nung; Clark, Ross A

2011-12-01

Knee extensor strength is an important correlate of physical function in patients with knee osteoarthritis; however, it remains unclear whether standing balance is also a correlate. The purpose of this study was to evaluate the cross-sectional associations of knee extensor strength, standing balance, and their interaction with physical function. One hundred four older adults with end-stage knee osteoarthritis awaiting a total knee replacement (mean ± SD age 67 ± 8 years) participated. Isometric knee extensor strength was measured using an isokinetic dynamometer. Standing balance performance was measured by the center of pressure displacement during quiet standing on a balance board. Physical function was measured by the self-report Short Form 36 (SF-36) questionnaire and by the 10-meter fast-pace gait speed test. After adjustment for demographic and knee pain variables, we detected significant knee strength by standing balance interaction terms for both SF-36 physical function and fast-pace gait speed. Interrogation of the interaction revealed that standing balance in the anteroposterior plane was positively related to physical function among patients with lower knee extensor strength. Conversely, among patients with higher knee extensor strength, the standing balance-physical function associations were, or tended to be, negative. These findings suggest that although standing balance was related to physical function in patients with knee osteoarthritis, this relationship was complex and dependent on knee extensor strength level. These results are of importance in developing intervention strategies and refining theoretical models, but they call for further study. Copyright © 2011 by the American College of Rheumatology.

Effect of static and dynamic muscle stretching as part of warm up procedures on knee joint proprioception and strength.

Science.gov (United States)

Walsh, Gregory S

2017-10-01

The importance of warm up procedures prior to athletic performance is well established. A common component of such procedures is muscle stretching. There is conflicting evidence regarding the effect of static stretching (SS) as part of warm up procedures on knee joint position sense (KJPS) and the effect of dynamic stretching (DS) on KJPS is currently unknown. The aim of this study was to determine the effect of dynamic and static stretching as part warm up procedures on KJPS and knee extension and flexion strength. This study had a randomised cross-over design and ten healthy adults (20±1years) attended 3 visits during which baseline KJPS, at target angles of 20° and 45°, and knee extension and flexion strength tests were followed by 15min of cycling and either a rest period (CON), SS, or DS and repeat KJPS and strength tests. All participants performed all conditions, one condition per visit. There were warm up×stretching type interactions for KJPS at 20° (p=0.024) and 45° (p=0.018), and knee flexion (p=0.002) and extension (pwarm up procedures. However, the negative impact of SS on muscle strength limits the utility of SS before athletic performance. If stretching is to be performed as part of a warm up, DS should be favoured over SS. Copyright © 2017 Elsevier B.V. All rights reserved.

Joint angles of the ankle, knee, and hip and loading conditions during split squats.

Science.gov (United States)

Schütz, Pascal; List, Renate; Zemp, Roland; Schellenberg, Florian; Taylor, William R; Lorenzetti, Silvio

2014-06-01

The aim of this study was to quantify how step length and the front tibia angle influence joint angles and loading conditions during the split squat exercise. Eleven subjects performed split squats with an additional load of 25% body weight applied using a barbell. Each subject's movements were recorded using a motion capture system, and the ground reaction force was measured under each foot. The joint angles and loading conditions were calculated using a cluster-based kinematic approach and inverse dynamics modeling respectively. Increases in the tibia angle resulted in a smaller range of motion (ROM) of the front knee and a larger ROM of the rear knee and hip. The external flexion moment in the front knee/hip and the external extension moment in the rear hip decreased as the tibia angle increased. The flexion moment in the rear knee increased as the tibia angle increased. The load distribution between the legs changed squat execution was varied. Our results describing the changes in joint angles and the resulting differences in the moments of the knee and hip will allow coaches and therapists to adapt the split squat exercise to the individual motion and load demands of athletes.

Prophylactic knee bracing alters lower-limb muscle forces during a double-leg drop landing.

Science.gov (United States)

Ewing, Katie A; Fernandez, Justin W; Begg, Rezaul K; Galea, Mary P; Lee, Peter V S

2016-10-03

Anterior cruciate ligament (ACL) injury can be a painful, debilitating and costly consequence of participating in sporting activities. Prophylactic knee bracing aims to reduce the number and severity of ACL injury, which commonly occurs during landing maneuvers and is more prevalent in female athletes, but a consensus on the effectiveness of prophylactic knee braces has not been established. The lower-limb muscles are believed to play an important role in stabilizing the knee joint. The purpose of this study was to investigate the changes in lower-limb muscle function with prophylactic knee bracing in male and female athletes during landing. Fifteen recreational athletes performed double-leg drop landing tasks from 0.30m and 0.60m with and without a prophylactic knee brace. Motion analysis data were used to create subject-specific musculoskeletal models in OpenSim. Static optimization was performed to calculate the lower-limb muscle forces. A linear mixed model determined that the hamstrings and vasti muscles produced significantly greater flexion and extension torques, respectively, and greater peak muscle forces with bracing. No differences in the timings of peak muscle forces were observed. These findings suggest that prophylactic knee bracing may help to provide stability to the knee joint by increasing the active stiffness of the hamstrings and vasti muscles later in the landing phase rather than by altering the timing of muscle forces. Further studies are necessary to quantify whether prophylactic knee bracing can reduce the load placed on the ACL during intense dynamic movements. Copyright © 2016 Elsevier Ltd. All rights reserved.

Risk factors associated with reduced work productivity among people with chronic knee pain.

Science.gov (United States)

Agaliotis, M; Fransen, M; Bridgett, L; Nairn, L; Votrubec, M; Jan, S; Heard, R; Mackey, M

2013-09-01

To determine the burden and risk factors associated with reduced work productivity among people with chronic knee pain. A longitudinal study, nested within a randomised controlled trial (RCT) evaluating the long-term effects of dietary supplements, was conducted among people with chronic knee pain in paid employment (n = 360). Participants recorded days off work (absenteeism) and reduced productivity while at work (presenteeism) for seven days every two months over a 12-month period in a study specific diary. Examined risk factors included knee pain severity, occupational group, radiographic disease severity, physical activity, body mass index (BMI), health-related quality of life (SF-12) and co-morbidity. Over the 12-month follow up period, 50 (14%) participants reported one or more days off work due to knee problems, while 283 (79%) reported reduced productivity while at work (presenteeism absenteeism was having an SF-12 Mental Component Summary (MCS) score labour (OR: 2.23 [1.09-4.59]) or manual labour (OR: 6.40 [1.44-28.35]) or a high maximum knee pain (4-6 out of 10) (OR: 2.29 [1.17-4.46]). This longitudinal study found that among this cohort of people with chronic knee pain, the burden of reduced work productivity is mainly attributable to presenteeism rather absenteeism. This study demonstrated that effective strategies to increase work productivity should focus on reducing knee pain or physical disability especially among workers in manual or semi-manual labour. © 2013 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

Heat generated by knee prostheses.

Science.gov (United States)

Pritchett, James W

2006-01-01

Temperature sensors were placed in 50 knees in 25 patients who had one or both joints replaced. Temperature recordings were made before walking, after walking, and after cycling. The heat generated in healthy, arthritic, and replaced knees was measured. The knee replacements were done using eight different prostheses. A rotating hinge knee prosthesis generated a temperature increase of 7 degrees C in 20 minutes and 9 degrees C in 40 minutes. An unconstrained ceramic femoral prosthesis articulating with a polyethylene tibial prosthesis generated a temperature increase of 4 degrees C compared with a healthy resting knee. The other designs using a cobalt-chrome alloy and high-density polyethylene had temperature increases of 5 degrees-7 degrees C with exercise. Frictional heat generated in a prosthetic knee is not immediately dissipated and may result in wear, creep, and other degenerative processes in the high-density polyethylene. Extended periods of elevated temperature in joints may inhibit cell growth and perhaps contribute to adverse performance via bone resorption or component loosening. Prosthetic knees generate more heat with activity than healthy or arthritic knees. More-constrained knee prostheses generate more heat than less-constrained prostheses. A knee with a ceramic femoral component generates less heat than a knee with the same design using a cobalt-chromium alloy.

Knee Injuries Are Associated with Accelerated Knee Osteoarthritis Progression: Data from the Osteoarthritis Initiative

Science.gov (United States)

Driban, Jeffrey B.; Eaton, Charles B.; Lo, Grace H.; Ward, Robert J.; Lu, Bing; McAlindon, Timothy E.

2014-01-01

Objective We aimed to evaluate if a recent knee injury was associated with accelerated knee osteoarthritis (KOA) progression. Methods In the Osteoarthritis Initiative (OAI) we studied participants free of KOA on their baseline radiographs (Kellgren-Lawrence [KL]knee that progressed to end-stage KOA (KL Grade 3 or 4) within 48 months, 2) common KOA progression: at least one knee increased in radiographic scoring within 48 months (excluding those defined as accelerated KOA), and 3) no KOA: no change in KL grade in either knee. At baseline, participants were asked if their knees had ever been injured and at each annual visit they were asked about injuries during the prior 12 months. We used multinomial logistic regressions to determine if a new knee injury was associated with the outcome of accelerated KOA or common KOA progression after adjusting for age, sex, body mass index, static knee malalignment, and systolic blood pressure. Results A knee injury during the total observation period was associated with accelerated KOA progression (n=54, odds ratio [OR]=3.14) but not common KOA progression (n=187, OR=1.08). Furthermore, a more recent knee injury (within a year of the outcome) was associated with accelerated (OR=8.46) and common KOA progression (OR=3.12). Conclusion Recent knee injuries are associated with accelerated KOA. Most concerning is that certain injuries may be associated with a rapid cascade towards joint failure in less than one year. PMID:24782446

Thigh-calf contact parameters for six high knee flexion postures: Onset, maximum angle, total force, contact area, and center of force.

Science.gov (United States)

Kingston, David C; Acker, Stacey M

2018-01-23

In high knee flexion, contact between the posterior thigh and calf is expected to decrease forces on tibiofemoral contact surfaces, therefore, thigh-calf contact needs to be thoroughly characterized to model its effect. This study measured knee angles and intersegmental contact parameters in fifty-eight young healthy participants for six common high flexion postures using motion tracking and a pressure sensor attached to the right thigh. Additionally, we introduced and assessed the reliability of a method for reducing noise in pressure sensor output. Five repetitions of two squatting, two kneeling, and two unilateral kneeling movements were completed. Interactions of posture by sex occurred for thigh-calf and heel-gluteal center of force, and thigh-calf contact area. Center of force in thigh-calf regions was farther from the knee joint center in females, compared to males, during unilateral kneeling (82 and 67 mm respectively) with an inverted relationship in the heel-gluteal region (331 and 345 mm respectively), although caution is advised when generalizing these findings from a young, relatively fit sample to a population level. Contact area was larger in females when compared to males (mean of 155.61 and 137.33 cm 2 across postures). A posture main effect was observed in contact force and sex main effects were present in onset and max angle. Males had earlier onset (121.0°) and lower max angle (147.4°) with onset and max angles having a range between movements of 8° and 3° respectively. There was a substantial total force difference of 139 N between the largest and smallest activity means. Force parameters measured in this study suggest that knee joint contact models need to incorporate activity-specific parameters when estimating loading. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anterior approach for knee arthrography

International Nuclear Information System (INIS)

Zurlo, J.V.; Towers, J.D.; Golla, S.

2001-01-01

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.)

Simultaneous bilateral total knee and ankle arthroplasty as a single surgical procedure.

Science.gov (United States)

Pagenstert, Geert; Hintermann, Beat

2011-10-13

Simultaneous osteoarthritis (OA) of the ankle joint complicates primary total knee arthroplasty (TKA). In such cases, rehabilitation of TKA is limited by debilitating ankle pain, but varus or valgus ankle arthritis may even compromise placement of knee prosthetic components. We present a patient with simultaneous bilateral valgus and patellofemoral OA of the knees and bilateral varus OA of the ankle joints that equally contributed to overall disability. This 63 years old, motivated and otherwise healthy patient was treated by simultaneous bilateral total knee and ankle arthroplasty (quadruple total joint arthroplasty, TJA) during the same anesthesia. Two years outcome showed excellent alignment and function of all four replaced joints. Postoperative time for rehabilitation, back to work (6th week) and hospital stay (12 days) of this special patient was markedly reduced compared to the usual course of separate TJA. Simultaneous quadruple TJA in equally disabling OA of bilateral deformed knees and ankles resulted in a better functional outcome and faster recovery compared to the average reported results after TKA and TAA in literature. However, careful preoperative planning, extensive patient education, and two complete surgical teams were considered essential for successful performance. To the best of our knowledge this is the first case report in literature about quadruple major total joint arthroplasty implanted during the same anesthesia in the same patient.

Simultaneous bilateral total knee and ankle arthroplasty as a single surgical procedure

Directory of Open Access Journals (Sweden)

Hintermann Beat

2011-10-01

Full Text Available Abstract Background Simultaneous osteoarthritis (OA of the ankle joint complicates primary total knee arthroplasty (TKA. In such cases, rehabilitation of TKA is limited by debilitating ankle pain, but varus or valgus ankle arthritis may even compromise placement of knee prosthetic components. Case presentation We present a patient with simultaneous bilateral valgus and patellofemoral OA of the knees and bilateral varus OA of the ankle joints that equally contributed to overall disability. This 63 years old, motivated and otherwise healthy patient was treated by simultaneous bilateral total knee and ankle arthroplasty (quadruple total joint arthroplasty, TJA during the same anesthesia. Two years outcome showed excellent alignment and function of all four replaced joints. Postoperative time for rehabilitation, back to work (6th week and hospital stay (12 days of this special patient was markedly reduced compared to the usual course of separate TJA. Conclusions Simultaneous quadruple TJA in equally disabling OA of bilateral deformed knees and ankles resulted in a better functional outcome and faster recovery compared to the average reported results after TKA and TAA in literature. However, careful preoperative planning, extensive patient education, and two complete surgical teams were considered essential for successful performance. To the best of our knowledge this is the first case report in literature about quadruple major total joint arthroplasty implanted during the same anesthesia in the same patient.

Prevalence of knee pain and knee OA in southern Sweden and the proportion that seeks medical care

DEFF Research Database (Denmark)

Turkiewicz, Aleksandra; Gerhardsson de Verdier, Maria; Engström, Gunnar

2015-01-01

OBJECTIVE: The aim of this study was to estimate the prevalence of frequent knee pain in radiographic, symptomatic and clinically defined knee OA in middle-aged and elderly patients and the proportion that seeks medical care. METHODS: In 2007 a random sample of 10 000 56- to 84-year-old residents...... of Malmö, Sweden, were questioned about knee pain. We classified subjects reporting knee pain with a duration of at least 4 weeks as having frequent knee pain. A random sample of 1300 individuals with frequent knee pain and 650 without were invited for assessment by the ACR clinical knee OA criteria...... and for bilateral weight-bearing knee radiography. We considered a Kellgren-Lawrence grade ≥2 as radiographic knee OA and that in combination with frequent knee pain as symptomatic knee OA. By linkage with the Skåne Healthcare Register, we determined the proportion of subjects that had consulted for knee OA or pain...

Knee joint stabilization therapy in patients with osteoarthritis of the knee: a randomized, controlled trial.

Science.gov (United States)

Knoop, J; Dekker, J; van der Leeden, M; van der Esch, M; Thorstensson, C A; Gerritsen, M; Voorneman, R E; Peter, W F; de Rooij, M; Romviel, S; Lems, W F; Roorda, L D; Steultjens, M P M

2013-08-01

To investigate whether an exercise program, initially focusing on knee stabilization and subsequently on muscle strength and performance of daily activities is more effective than an exercise program focusing on muscle strength and performance of daily activities only, in reducing activity limitations in patients with knee osteoarthritis (OA) and instability of the knee joint. A single-blind, randomized, controlled trial involving 159 knee OA patients with self-reported and/or biomechanically assessed knee instability, randomly assigned to two treatment groups. Both groups received a supervised exercise program for 12 weeks, consisting of muscle strengthening exercises and training of daily activities, but only in the experimental group specific knee joint stabilization training was provided. Outcome measures included activity limitations (Western Ontario and McMaster Universities Osteoarthritis Index - WOMAC physical function, primary outcome), pain, global perceived effect and knee stability. Both treatment groups demonstrated large (∼20-40%) and clinically relevant reductions in activity limitations, pain and knee instability, which were sustained 6 months post-treatment. No differences in effectiveness between experimental and control treatment were found on WOMAC physical function (B (95% confidence interval - CI) = -0.01 (-2.58 to 2.57)) or secondary outcome measures, except for a higher global perceived effect in the experimental group (P = 0.04). Both exercise programs were highly effective in reducing activity limitations and pain and restoring knee stability in knee OA patients with instability of the knee. In knee OA patients suffering from knee instability, specific knee joint stabilization training, in addition to muscle strengthening and functional exercises, does not seem to have any additional value. Dutch Trial Register (NTR) registration number: NTR1475. Copyright © 2013 Osteoarthritis Research Society International. Published by Elsevier

[Correlations Between Joint Proprioception, Muscle Strength, and Functional Ability in Patients with Knee Osteoarthritis].

Science.gov (United States)

Chen, Yoa; Yu, Yong; He, Cheng-qi

2015-11-01

To establish correlations between joint proprioception, muscle flexion and extension peak torque, and functional ability in patients with knee osteoarthritis (OA). Fifty-six patients with symptomatic knee OA were recruited in this study. Both proprioceptive acuity and muscle strength were measured using the isomed-2000 isokinetic dynamometer. Proprioceptive acuity was evaluated by establishing the joint motion detection threshold (JMDT). Muscle strength was evaluated by Max torque (Nm) and Max torque/weight (Nm/ kg). Functional ability was assessed by the Western Ontario and McMaster Universities Osteoarthritis Index physical function (WOMAC-PF) questionnaire. Correlational analyses were performed between proprioception, muscle strength, and functional ability. A multiple stepwise regression model was established, with WOMAC-PF as dependent variable and patient age, body mass index (BMI), visual analogue scale (VAS)-score, mean grade for Kellgren-Lawrance of both knees, mean strength for quadriceps and hamstring muscles of both knees, and mean JMDT of both knees as independent variables. Poor proprioception (high JMDT) was negatively correlated with muscle strength (Pcoefficient (B) = 0.385, P<0.50 and high VAS-scale score (B=0.347, P<0.05) were significant predictors of WOMAC-PF score. Patients with poor proprioception is associated with poor muscle strength and limitation in functional ability. Patients with symptomatic OA of knees commonly endure with moderate to considerable dysfunction, which is associated with poor proprioception (high JMDT) and high VAS-scale score.

Helical axes of skeletal knee joint motion during running.

Science.gov (United States)

van den Bogert, A J; Reinschmidt, C; Lundberg, A

2008-01-01

The purpose of this study was to determine the changes in the axis of rotation of the knee that occur during the stance phase of running. Using intracortical pins, the three-dimensional skeletal kinematics of three subjects were measured during the stance phase of five running trials. The stance phase was divided into equal motion increments for which the position and orientation of the finite helical axes (FHA) were calculated relative to a tibial reference frame. Results were consistent within and between subjects. At the beginning of stance, the FHA was located at the midepicondylar point and during the flexion phase moved 20mm posteriorly and 10mm distally. At the time of peak flexion, the FHA shifted rapidly by about 10-20mm in proximal and posterior direction. The angle between the FHA and the tibial transverse plane increased gradually during flexion, to about 15 degrees of medial inclination, and then returned to zero at the start of the extension phase. These changes in position and orientation of FHA in the knee should be considered in analyses of muscle function during human movement, which require moment arms to be defined relative to a functional rotation axis. The finding that substantial changes in axis of rotation occurred independent of flexion angle suggests that musculoskeletal models must have more than one kinematic degree-of-freedom at the knee. The same applies to the design of knee prostheses, if the goal is to restore normal muscle function.

Knee Replacement

Science.gov (United States)

... days. Medications prescribed by your doctor should help control pain. During the hospital stay, you'll be encouraged to move your ... exercise your new knee. After you leave the hospital, you'll continue physical ... mobility and a better quality of life. And most knee replacements can be ...

Jumper's Knee (Patellar Tendonitis) (For Parents)

Science.gov (United States)

... Safe Videos for Educators Search English Español Jumper's Knee (Patellar Tendonitis) KidsHealth / For Parents / Jumper's Knee (Patellar ... prevent continued damage to the knee. How the Knee Works To understand how jumper's knee happens, it ...

The pediatric knee.

Science.gov (United States)

Orth, Robert C

2013-03-01

Knee pain is a common problem in children and adolescents, and MRI of the knee is the most commonly performed pediatric cross-sectional musculoskeletal imaging exam. The purpose of this pictorial review is to highlight differences between adult and pediatric knee imaging with an emphasis on normal developmental variants, injury and disease patterns unique to children and adolescents, and differences in response and presentation to conditions affecting both adults and children.

Randomized trial investigating the efficacy of manual lymphatic drainage to improve early outcome after total knee arthroplasty.

Science.gov (United States)

Ebert, Jay R; Joss, Brendan; Jardine, Berit; Wood, David J

2013-11-01

To investigate the efficacy of manual lymphatic drainage (MLD) in the early postoperative period after total knee arthroplasty (TKA) to reduce edema and pain and improve knee range of motion. Prospective randomized controlled trial. Private hospital and functional rehabilitation clinic. Consecutive sample of patients (N=43; 53 knees) scheduled for TKA. MLD (vs no MLD) on days 2, 3, and 4 postoperatively. Both groups underwent conventional, concomitant physical therapy. Clinical assessment was undertaken pre- and postoperatively prior to and after the designated postoperative MLD sessions (days 2, 3, and 4) and at 6 weeks postsurgery. This included active knee flexion and extension range of motion, lower limb girths (ankle, midpatella, thigh, and calf), and knee pain using a numeric rating scale and the Knee Injury and Osteoarthritis Outcome Score. A significant group effect was observed for active knee flexion, with post hoc tests demonstrating a significantly greater active knee flexion in the MLD group when compared with the control (no MLD) group at the final measure prior to hospital discharge (day 4 postsurgery) and at 6 weeks postsurgery. There were no further group effects observed for the remaining patient-reported and functional outcomes. MLD in the early postoperative stages after TKA appears to improve active knee flexion up to 6 weeks postsurgery, in addition to conventional care. Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Reliability of Concentric, Eccentric and Isometric Knee Extension and Flexion when using the REV9000 Isokinetic Dynamometer

DEFF Research Database (Denmark)

de Carvalho Froufe Andrade, Alberto César Pereira; Caserotti, Paolo; de Carvalho, Carlos Manuel Pereira

2013-01-01

The aim of this study was to assess the reliability of isokinetic and ISO knee extensor and flexor muscle strength when using the REV9000 (Technogym) isokinetic dynamometer. Moreover, the reliability of several strength imbalance indices and bilateral ratios were also examined. Twenty-four physic...

Difference in the recruitment of hip and knee muscles between back squat and plyometric squat jump.

Directory of Open Access Journals (Sweden)

Norihide Sugisaki

Full Text Available Athletes who aim to improve both muscular endurance and power often perform exercises that involve similar joint actions under different lifting conditions, such as changes in the load or speed, which are implemented at different times during a periodized exercise program or simultaneously. The prescribed exercises are considered to recruit the same muscles even if the lifting conditions differ to each other. The present study aimed to clarify this by examining whether the recruitment of individual hip and knee muscles during the squat exercise differs between lifting conditions adopted for muscular endurance and power training regimens. Moderately trained men performed back squats (BS, with a load of approximately 60% of one repetition maximum, as a muscular endurance training exercise, and they performed plyometric squat jumping (PSJ for power training. During each exercise, the lower limb joint torques and the recruitment of five hip and knee muscles were determined with inverse-dynamics and T2-weighted magnetic resonance imaging, respectively. While the maximal and mean knee joint torques were greater during PSJ than during BS (p<0.01, the T2 values for the quadriceps femoris muscle did not differ between the exercises. In contrast, the T2 values of the gluteus maximus and hip adductor muscles were higher during PSJ (p<0.05 than during BS, although there was no significant difference in the mean hip extension torque between the two exercises. The current results indicate that the individual use of the agonist muscles differs between BS and PSJ, and it does not always correspond with the joint kinetics during the exercises. Therefore, in addition to the exercise type, the lifting condition should also be taken into consideration as a determinant of the major muscles trained during a resistance exercise.

Long-term stress distribution patterns of the ankle joint in varus knee alignment assessed by computed tomography osteoabsorptiometry.

Science.gov (United States)

Onodera, Tomohiro; Majima, Tokifumi; Iwasaki, Norimasa; Kamishima, Tamotsu; Kasahara, Yasuhiko; Minami, Akio

2012-09-01

The stress distribution of an ankle under various physiological conditions is important for long-term survival of total ankle arthroplasty. The aim of this study was to measure subchondral bone density across the distal tibial joint surface in patients with malalignment/instability of the lower limb. We evaluated subchondral bone density across the distal tibial joint in patients with malalignment/instability of the knee by computed tomography (CT) osteoabsorptiometry from ten ankles as controls and from 27 ankles with varus deformity/instability of the knee. The quantitative analysis focused on the location of the high-density area at the articular surface, to determine the resultant long-term stress on the ankle joint. The area of maximum density of subchondral bone was located in the medial part in all subjects. The pattern of maximum density in the anterolateral area showed stepwise increases with the development of varus deformity/instability of the knee. Our results should prove helpful for designing new prostheses and determining clinical indications for total ankle arthroplasty.

Immediate effect of Masai Barefoot Technology shoes on knee joint moments in women with knee osteoarthritis.

Science.gov (United States)

Tateuchi, Hiroshige; Taniguchi, Masashi; Takagi, Yui; Goto, Yusuke; Otsuka, Naoki; Koyama, Yumiko; Kobayashi, Masashi; Ichihashi, Noriaki

2014-01-01

Footwear modification can beneficially alter knee loading in patients with knee osteoarthritis. This study evaluated the effect of Masai Barefoot Technology shoes on reductions in external knee moments in patients with knee osteoarthritis. Three-dimensional motion analysis was used to examine the effect of Masai Barefoot Technology versus control shoes on the knee adduction and flexion moments in 17 women (mean age, 63.6 years) with radiographically confirmed knee osteoarthritis. The lateral and anterior trunk lean values, knee flexion and adduction angles, and ground reaction force were also evaluated. The influence of the original walking pattern on the changes in knee moments with Masai Barefoot Technology shoes was evaluated. The knee flexion moment in early stance was significantly reduced while walking with the Masai Barefoot Technology shoes (0.25±0.14Nm/kgm) as compared with walking with control shoes (0.30±0.19 Nm/kgm); whereas the knee adduction moment showed no changes. Masai Barefoot Technology shoes did not increase compensatory lateral and anterior trunk lean. The degree of knee flexion moment in the original walking pattern with control shoes was correlated directly with its reduction when wearing Masai Barefoot Technology shoes by multiple linear regression analysis (adjusted R2=0.44, Pknee flexion moment during walking without increasing the compensatory trunk lean and may therefore reduce external knee loading in women with knee osteoarthritis. Copyright © 2014 Elsevier B.V. All rights reserved.

Arthroscopic surgery for degenerative knee

DEFF Research Database (Denmark)

Thorlund, J B; Juhl, C B; Roos, E M

2015-01-01

OBJECTIVE: To determine benefits and harms of arthroscopic knee surgery involving partial meniscectomy, debridement, or both for middle aged or older patients with knee pain and degenerative knee disease. DESIGN: Systematic review and meta-analysis. MAIN OUTCOME MEASURES: Pain and physical function....... RESULTS: The search identified nine trials assessing the benefits of knee arthroscopic surgery in middle aged and older patients with knee pain and degenerative knee disease. The main analysis, combining the primary endpoints of the individual trials from three to 24 months postoperatively, showed a small...... included symptomatic deep venous thrombosis (4.13 (95% confidence interval 1.78 to 9.60) events per 1000 procedures), pulmonary embolism, infection, and death. CONCLUSIONS: The small inconsequential benefit seen from interventions that include arthroscopy for the degenerative knee is limited in time...

Noninjured Knees of Patients With Noncontact ACL Injuries Display Higher Average Anterior and Internal Rotational Knee Laxity Compared With Healthy Knees of a Noninjured Population.

Science.gov (United States)

Mouton, Caroline; Theisen, Daniel; Meyer, Tim; Agostinis, Hélène; Nührenbörger, Christian; Pape, Dietrich; Seil, Romain

2015-08-01

Excessive physiological anterior and rotational knee laxity is thought to be a risk factor for noncontact anterior cruciate ligament (ACL) injuries and inferior reconstruction outcomes, but no thresholds have been established to identify patients with increased laxity. (1) To determine if the healthy contralateral knees of ACL-injured patients have greater anterior and rotational knee laxity, leading to different laxity profiles (combination of laxities), compared with healthy control knees and (2) to set a threshold to help discriminate anterior and rotational knee laxity between these groups. Case-sectional study; Level of evidence, 3. A total of 171 healthy contralateral knees of noncontact ACL-injured patients (ACL-H group) and 104 healthy knees of control participants (CTL group) were tested for anterior and rotational laxity. Laxity scores (measurements corrected for sex and body mass) were used to classify knees as hypolax (score 1). Proportions of patients in each group were compared using χ(2) tests. Receiver operating characteristic curves were computed to discriminate laxity between the groups. Odds ratios were calculated to determine the probability of being in the ACL-H group. The ACL-H group displayed greater laxity scores for anterior displacement and internal rotation in their uninjured knee compared with the CTL group (P knees of patients with noncontact ACL injuries display different laxity values both for internal rotation and anterior displacement compared with healthy control knees. The identification of knee laxity profiles may be of relevance for primary and secondary prevention programs of noncontact ACL injuries. © 2015 The Author(s).

Knee extension and flexion muscle power after anterior cruciate ligament reconstruction with patellar tendon graft or hamstring tendons graft: a cross-sectional comparison 3 years post surgery

DEFF Research Database (Denmark)

Ageberg, Eva; Roos, Harald; Silbernagel, Karin

2008-01-01

Hamstring muscles play a major role in knee-joint stabilization after anterior cruciate ligament (ACL) injury. Weakness of the knee extensors after ACL reconstruction with patellar tendon (PT) graft, and in the knee flexors after reconstruction with hamstring tendons (HT) graft has been observed ...

[Acute rhabdomyolysis after spinal anesthesia for knee arthroscopy].

Science.gov (United States)

Bouché, P M; Chavagnac, B; Cognet, V; Banssillon, V

2001-08-01

We report an observation of acute rhabdomyolysis of gluteus maximum muscles occurring in a non-obese patient installed in supine position that underwent knee arthroscopy under spinal anaesthesia. The patient had insulin-dependent diabetes melitus with documented microangiopathy. The interest of this observation resides in the occurrence of the syndrome after a short period of time (one hour) of installation in the supine position in a patient that did not have any of the generally described risk factors of rhabdomyolysis.

The influence of knee pain location on symptoms, functional status and knee-related quality of life in older adults with chronic knee pain: data from the Osteoarthritis Initiative

Science.gov (United States)

Farrokhi, Shawn; Chen, Yi-Fan; Piva, Sara R.; Fitzgerald, G. Kelley; Jeong, Jong-Hyeon; Kwoh, C. Kent

2015-01-01

Objective To evaluate whether knee pain location can influence symptoms, functional status and knee-related quality of life in older adults with chronic knee pain. Methods A total of 2959 painful knees from the Osteoarthritis Initiative database were analyzed. Trained interviewers recorded patient-reported location of knee pain. Painful knees were divided into three groups of patellofemoral only pain, tibiofemoral only pain, and combined pain. Self-reported knee-specific symptoms, functional status and knee-related quality of life were assessed using the Knee Injury and Osteoarthritis Outcome Score (KOOS). Results The most common knee pain pattern was tibiofemoral only pain (62%), followed by patellofemoral only pain (23%) and combined pain (15%). The combined pain pattern was associated with greater odds of reporting pain, symptoms, sports or recreational activity limitations and lower knee-related quality of life compared to either isolated knee pain patterns, after adjusting for demographics and radiographic disease severity. Individual item analysis further revealed that patients with combined pain had greater odds of reporting difficulty with daily weightbearing activities that required knee bending compared to tibiofemoral or patellofemoral only pain patterns. Furthermore, symptoms, functional status, and knee-related quality of life were comparable between patients with patellofemoral and tibiofemoral only pain patterns, after adjusting for demographics and radiographic disease severity. Discussion Combined patellofemoral and tibiofemoral pain is associated with poorer clinical presentation compared to isolated knee pain from either location. Additionally, patellofemoral pain in isolation may be as important as tibiofemoral pain in causing symptoms and functional limitation in older adults with chronic knee pain. PMID:26308705

Focal knee lesions in knee pairs of asymptomatic and symptomatic subjects with OA risk factors—Data from the Osteoarthritis Initiative

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Chundru, Renu, E-mail: renu.chundru@ucsf.edu [Musculoskeletal and Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 (United States); Baum, Thomas, E-mail: thbaum@gmx.de [Musculoskeletal and Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 (United States); Nardo, Lorenzo, E-mail: lorenzo.nardo@ucsf.edu [Musculoskeletal and Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 (United States); Nevitt, Michael C., E-mail: MNevitt@psg.ucsf.edu [Department of Epidemiology and Biostatistics, University of California San Francisco, 185 Berry Street, Suite 5700, San Francisco, CA 94107 (United States); Lynch, John, E-mail: JLynch@psg.ucsf.edu [Department of Epidemiology and Biostatistics, University of California San Francisco, 185 Berry Street, Suite 5700, San Francisco, CA 94107 (United States); McCulloch, Charles E., E-mail: CMcCulloch@epi.ucsf.edu [Department of Epidemiology and Biostatistics, University of California San Francisco, 185 Berry Street, Suite 5700, San Francisco, CA 94107 (United States); Link, Thomas M., E-mail: tmlink@radiology.ucsf.edu [Musculoskeletal and Quantitative Imaging Research Group, Department of Radiology and Biomedical Imaging, University of California San Francisco, 185 Berry Street, Suite 350, San Francisco, CA 94107 (United States)

2013-08-15

Objective: To better understand the relationship between knee pain and bilateral knee lesions, we compared focal knee lesions in knee pairs of subjects with no, unilateral, and bilateral knee pain, and risk factors for knee osteoarthritis (OA), but no radiographic knee OA. Materials and methods: We examined both knees of 120 subjects from the Osteoarthritis Initiative database. We randomly selected 60 subjects aged 45–55 years with OA risk factors, no knee pain (WOMAC pain score = 0) and no radiographic OA (KL-score ≤1) in both knees. We also selected two comparison groups with OA risk factors and no radiographic OA in both knees, but with knee pain (WOMAC pain score ≥5): 30 subjects with right only knee pain and 30 subjects with bilateral knee pain. All subjects underwent 3T MRI of both knees and focal knee lesions were assessed. Results: Statistically significant associations between prevalence of focal lesions in the right and left knee with odds ratios up to 13.5 were found in all three subject groups. Focal knee lesions were generally not associated with pain in analyses comparing knee pairs of subjects with unilateral knee pain (p > 0.05). The prevalence and severity of focal knee lesions were not significantly different in knee pairs of subjects with no knee pain and those with bilateral knee pain (p > 0.05). Conclusion: Focal knee lesions in the right and left knee of subjects with OA risk factors were positively associated with each other independent of knee pain status, and were not statistically significant different between knees in subjects with unilateral knee pain.

Focal knee lesions in knee pairs of asymptomatic and symptomatic subjects with OA risk factors—Data from the Osteoarthritis Initiative

International Nuclear Information System (INIS)

Chundru, Renu; Baum, Thomas; Nardo, Lorenzo; Nevitt, Michael C.; Lynch, John; McCulloch, Charles E.; Link, Thomas M.

2013-01-01

Objective: To better understand the relationship between knee pain and bilateral knee lesions, we compared focal knee lesions in knee pairs of subjects with no, unilateral, and bilateral knee pain, and risk factors for knee osteoarthritis (OA), but no radiographic knee OA. Materials and methods: We examined both knees of 120 subjects from the Osteoarthritis Initiative database. We randomly selected 60 subjects aged 45–55 years with OA risk factors, no knee pain (WOMAC pain score = 0) and no radiographic OA (KL-score ≤1) in both knees. We also selected two comparison groups with OA risk factors and no radiographic OA in both knees, but with knee pain (WOMAC pain score ≥5): 30 subjects with right only knee pain and 30 subjects with bilateral knee pain. All subjects underwent 3T MRI of both knees and focal knee lesions were assessed. Results: Statistically significant associations between prevalence of focal lesions in the right and left knee with odds ratios up to 13.5 were found in all three subject groups. Focal knee lesions were generally not associated with pain in analyses comparing knee pairs of subjects with unilateral knee pain (p > 0.05). The prevalence and severity of focal knee lesions were not significantly different in knee pairs of subjects with no knee pain and those with bilateral knee pain (p > 0.05). Conclusion: Focal knee lesions in the right and left knee of subjects with OA risk factors were positively associated with each other independent of knee pain status, and were not statistically significant different between knees in subjects with unilateral knee pain

Multiple Nonspecific Sites of Joint Pain Outside the Knees Develop in Persons With Knee Pain.

Science.gov (United States)

Felson, David T; Niu, Jingbo; Quinn, Emily K; Neogi, Tuhina; Lewis, Cara L; Lewis, Cora E; Frey Law, Laura; McCulloch, Chuck; Nevitt, Michael; LaValley, Michael

2017-02-01

Many persons with knee pain have joint pain outside the knee, but despite the impact and high frequency of this pain, its distribution and causes have not been studied. We undertook this study to test the hypothesis of those studying gait abnormalities who have suggested that knee pain causes pain in adjacent joints but that pain adaptation strategies are highly individualized. We studied persons ages 50-79 years with or at high risk of knee osteoarthritis who were recruited from 2 community-based cohorts, the Multicenter Osteoarthritis Study and the Osteoarthritis Initiative, and we followed them up for 5-7 years. We excluded those with knee pain at baseline and compared those who had developed knee pain at the first follow-up examination (the index visit) with those who had not. We examined pain on most days at joint regions outside the knee in examinations after the index visit. Logistic regression analyses examined the risk of joint-specific pain adjusted for age, sex, body mass index, and symptoms of depression, and we performed sensitivity analyses excluding those with widespread pain. In the combined cohorts, 693 persons had knee pain at the index visit and 2,793 did not. A total of 79.6% of those with bilateral knee pain and 63.8% of those with unilateral knee pain had pain during follow-up in a joint region outside the knee, compared with 49.9% of those without knee pain. There was an increased risk of pain at most extremity joint sites, without a predilection for specific sites. Results were unchanged when those with widespread pain were excluded. Persons with chronic knee pain are at increased risk of pain in multiple joints in no specific pattern. © 2016, American College of Rheumatology.

Strength and power of knee extensor muscles

Directory of Open Access Journals (Sweden)

Knežević Olivera

2011-01-01

Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for

The physiological cost index of walking with a powered knee-ankle-foot orthosis in subjects with poliomyelitis: A pilot study.

Science.gov (United States)

Arazpour, Mokhtar; Ahmadi Bani, Monireh; Samadian, Mohammad; Mousavi, Mohammad E; Hutchins, Stephen W; Bahramizadeh, Mahmood; Curran, Sarah; Mardani, Mohammad A

2016-08-01

A powered knee-ankle-foot orthosis was developed to provide restriction of knee flexion during stance phase and active flexion and extension of the knee during swing phase of gait. The purpose of this study was to determine its effect on the physiological cost index, walking speed and the distance walked in people with poliomyelitis compared to when walking with a knee-ankle-foot orthosis with drop lock knee joints. Quasi experimental study. Seven subjects with poliomyelitis volunteered for the study and undertook gait analysis with both types of knee-ankle-foot orthosis. Walking with the powered knee-ankle-foot orthosis significantly reduced walking speed (p = 0.015) and the distance walked (p = 0.004), and also, it did not improve physiological cost index values (p = 0.009) compared to walking with the locked knee-ankle-foot orthosis. Using a powered knee-ankle-foot orthosis did not significantly improve any of the primary outcome measures during walking for poliomyelitis subjects. This powered knee-ankle-foot orthosis design did not improve the physiological cost index of walking for people with poliomyelitis when compared to walking with a knee-ankle-foot orthosis with drop lock knee joints. This may have been due to the short training period used or the bulky design and additional weight of the powered orthosis. Further research is therefore warranted. © The International Society for Prosthetics and Orthotics 2015.

Effect of hip and knee position on tensor fasciae latae elongation during stretching: An ultrasonic shear wave elastography study.

Science.gov (United States)

Umehara, Jun; Ikezoe, Tome; Nishishita, Satoru; Nakamura, Masatoshi; Umegaki, Hiroki; Kobayashi, Takuya; Fujita, Kosuke; Ichihashi, Noriaki

2015-12-01

Decreased flexibility of the tensor fasciae latae is one factor that causes iliotibial band syndrome. Stretching has been used to improve flexibility or tightness of the muscle. However, no studies have investigated the effective stretching position for the tensor fasciae latae using an index to quantify muscle elongation in vivo. The aim of this study was to investigate the effects of hip rotation and knee angle on tensor fasciae latae elongation during stretching in vivo using ultrasonic shear wave elastography. Twenty healthy men participated in this study. The shear elastic modulus of the tensor fasciae latae was calculated using ultrasonic shear wave elastography. Stretching was performed at maximal hip adduction and maximal hip extension in 12 different positions with three hip rotation conditions (neutral, internal, and external rotations) and four knee angles (0°, 45°, 90°, and 135°). Two-way analysis of variance showed a significant main effect for knee angle, but not for hip rotation. The post-hoc test for knee angle indicated that the shear elastic modulus at 90° and 135° were significantly greater than those at 0° and 45°. Our results suggest that adding hip rotation to the stretching position with hip adduction and extension may have less effect on tensor fasciae latae elongation, and that stretching at >90° of knee flexion may effectively elongate the tensor fasciae latae. Copyright © 2015 Elsevier Ltd. All rights reserved.

Association of knee pain and different definitions of knee osteoarthritis with health-related quality of life

DEFF Research Database (Denmark)

Kiadaliri, A. A.; Lamm, C.J.; Gerhardsson de Verdier, Maria

2016-01-01

Background: While the impact of knee pain and knee osteoarthritis (OA) on health-related quality of life (HRQoL) has been investigated in the literature, there is a lack of knowledge on the impact of different definitions of OA on HRQoL. The main aim of this study was to measure and compare...... among references (neither knee pain nor OA) was 42 %. The participants with knee pain and OA had all HRQoL measures lower compared to those with knee pain but no OA. The ACR clinical definition of knee OA was associated with lower HRQoL than the definition based on radiographic knee OA (adjusted...

Fast track in total hip and knee arthroplasty--experiences from Hvidovre University Hospital, Denmark

DEFF Research Database (Denmark)

Husted, Henrik; Holm, Gitte

2006-01-01