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Prior studies have explored the relationship between knee valgus and musculoskeletal variables to formulate injury prevention programs, primarily for females. Nonetheless, there is insufficient evidence pertaining to professional male soccer players. Here, the aim was to test the correlation of lateral trunk inclination, hip adduction, hip internal rotation, ankle dorsiflexion range of motion, and hip isometric strength with knee valgus during the single-leg vertical jump test. Twenty-four professional male soccer players performed a single-leg vertical hop test, hip strength assessments, and an ankle dorsiflexion range of motion test. A motion analysis system was employed for kinematic analysis. Maximal isometric hip strength and ankle dorsiflexion range of motion were tested using a handheld dynamometer and a digital inclinometer, respectively. The correlation of peak knee valgus with peak lateral trunk inclination was.43 during the landing phase (P =.04) and with peak hip internal rotation was −.68 (P <.001). For knee valgus angular displacement, only peak lateral trunk inclination presented a moderate positive correlation (r =.40, P =.05). This study showed that trunk and hip kinematics are associated with knee valgus, which could consequently lead to increased knee overload in male professional soccer players following a unilateral vertical landing test. [ABSTRACT FROM AUTHOR]

Knee joint contact forces are commonly estimated via surrogate measures (i.e., external knee adduction moments or musculoskeletal modeling). Despite its capabilities, modeling is not optimal for clinicians or persons with limited experience. The purpose of this study was to design a novel prediction method for knee joint contact forces that is simplistic in terms of required inputs. This study included marker trajectories and instrumented knee forces during normal walking from the “Grand Challenge” (n = 6) and “CAMS” (n = 2) datasets. Inverse kinematics were used to derive stance phase hip (sagittal, frontal, transverse), knee (sagittal, frontal), ankle (sagittal), and trunk (frontal) kinematics. A long-short term memory network (LSTM) was created using matlab to predict medial and lateral knee force waveforms using combinations of the kinematics. The Grand Challenge and CAMS datasets trained and tested the network, respectively. Musculoskeletal modeling forces were derived using static optimization and joint reaction tools in OpenSim. Waveform accuracy was determined as the proportion of variance and root-mean-square error between network predictions and in vivo data. The LSTM network was highly accurate for medial forces (R² = 0.77, RMSE = 0.27 BW) and required only frontal hip and knee and sagittal hip and ankle kinematics. Modeled medial force predictions were excellent (R² = 0.77, RMSE = 0.33 BW). Lateral force predictions were poor for both methods (LSTM R² = 0.18, RMSE = 0.08 BW; modeling R² = 0.21, RMSE = 0.54 BW). The designed LSTM network outperformed most reports of musculoskeletal modeling, including those reached in this study, revealing knee joint forces can accurately be predicted by using only kinematic input variables. [ABSTRACT FROM AUTHOR]

(1) This study examined the impact of fatigue and unanticipated factors on knee biomechanics during sidestep cutting and lateral shuffling in female basketball players, assessing the potential for non-contact anterior cruciate ligament (ACL) injuries. (2) Twenty-four female basketball players underwent fatigue induction and unanticipated change of direction tests, and kinematic and kinetic parameters were collected before and after fatigue with a Vicon motion capture system and Kistler ground reaction force (GRF) sensor. (3) Analysis using two-way repeated-measures ANOVA showed no significant interaction between fatigue and unanticipated factors on joint kinematics and kinetics. Unanticipated conditions significantly increased the knee joint flexion and extension angle (p < 0.01), decreased the knee flexion moment under anticipated conditions, and increased the knee valgus moment after fatigue (p ≤ 0.05). One-dimensional statistical parametric mapping (SPM1d) results indicated significant differences in GRF during sidestep cutting and knee inversion and rotation moments during lateral shuffling post-fatigue. (4) Unanticipated factors had a greater impact on knee load patterns, raising ACL injury risk. Fatigue and unanticipated factors were independent risk factors and should be considered separately in training programs to prevent lower limb injuries. [ABSTRACT FROM AUTHOR]

The aim of the study was to verify the effects of foot progression angle (FPA) modification during walking on the internal moments of the ankle and knee joints in individuals with knee osteoarthritis (OA). Biomechanical changes such as increased knee adduction moment (KAM) during walking are known to be involved in the development and severity of knee OA. Although various FPA modifications during gait have been applied to reduce peak KAM, few studies have investigated the effects of applying toe-in or toe-out walking modifications for knee OA on peak KAM and three-dimensional (3D) moments of the ankle joint. Kinetic moment variables were acquired from 35 individuals with medial knee compartment OA. A 3D motion analysis system and two force platforms were used to acquire KAM and 3D moments of both ankle joints during gait. Visual3D was used to obtain final moment data for statistical processing. Repeated-measures analysis of variance with Bonferroni adjustment was used to compare kinetic and kinematic values for each FPA walking condition. There was a significant decrease (p < 0.01) in first peak KAM when walking with an internal rotation foot position compared to normal foot position walking. Also, there was a significant decrease (p < 0.01) in second peak KAM when walking with an external rotation foot position compared to normal foot position walking. Compared to a normal foot position, peak ankle inversion moment of the external rotation foot position walking showed a significant decrease (p < 0.05). There were no interactive effects between FPA condition and limb sides for any KAM values (p > 0.05). The results showed no significant increase in the ankle joint moment value during gait for FPA modification conditions. Thus, the clinical implications of this study suggest that modification of the FPA in patients with OA to reduce KAM does not negatively impact the 3D ankle moments. [ABSTRACT FROM AUTHOR]

Gait analysis offers vital insights into human movement, aiding in the diagnosis, treatment, and rehabilitation of various conditions. Analyzing gait in corridors, rather than in lab, provides unique advantages for a more comprehensive understanding of human locomotion. However, limited dedicated technologies constrain gait data analysis in this context. In this study, a markerless gait analysis system using an Azure Kinect sensor mounted on a mobile robot is proposed and validated as a potential solution for gait analysis in corridors. Ten healthy participants (4 males and 6 females) underwent two tests. The first test (5 trials per participant) took place in the laboratory. Here, Azure Kinect performance was validated against a Vicon system, assessing eight gait signals and 22 gait parameters. The second test (2 trials per participant) was performed in the corridors over a 32‐m walking distance to compare this gait pattern with the one developed within the laboratory. The intrasession Intraclass Correlation Coefficient (ICC) reliability for in‐lab experiments was assessed by calculating the ICC between gait cycles captured in each session per participant. Notably, knee flexion/extension (ICC‐0.95), hip flexion/extension (ICC‐0.96), pelvis rotation (ICC‐0.88), and interankle distance (ICC‐0.98) demonstrated excellent reliability with high confidence. Similarly, hip adduction/abduction showed good reliability (ICC‐0.79), while trunk rotation exhibited moderate reliability (ICC‐0.72). In contrast, both trunk tilt (ICC‐0.24) and pelvis tilt (ICC‐0.41) consistently displayed lower reliability. This was observed for both the Vicon and the Azure systems, highlighting the intricate nature of capturing precise data for these specific signals in both systems. Validity outcomes indicated comparable error rates to literature standards (12.68° $12.68^\circ $ knee flexion/extension, 5.54° $5.54^\circ $ hip flexion/extension, and 3.45° $3.45^\circ $ hip adduction/abduction), with 11 parameters having no significant differences from Vicon. Comparison of in‐lab and in‐corridor experiments show that individuals exhibit significantly longer stride time (1.10 s vs. 1.05 s), lower pelvis tilt (6.83° $6.83^\circ $ vs. 9.39° $9.39^\circ $), and lower minimum pelvis rotation (−5.82° $-5.82^\circ $ vs. −14.61° $-14.61^\circ $) when walking in the laboratory. This study demonstrates promising outcomes in outdoor gait analysis with a robot‐mounted camera, revealing significant distinctions from controlled laboratory evaluations [ABSTRACT FROM AUTHOR]

Objectives: This study aimed to compare three-dimensional kinematic of the trunk, pelvis, hip, and knee during the single-leg squat and hip torque in individuals with and without isolated patellofemoral osteoarthritis (PFOA). Patients and methods: This cross-sectional study evaluated trunk, pelvis, hip, and knee kinematics at 30°, 45°, and 60° knee flexion during the single-leg squat using the Vicon motion capture and analysis system, the Nexus System 2.1.1, and 3D Motion Monitor software. Sixteen individuals (8 males, 8 females; mean age: 49.3±6.2 years; range 40 to 61 years) participated in the study, of which eight were PFOA patients and eight were healthy controls. Isometric hip abductor, extensor, and external rotator torques were evaluated using a handheld dynamometer. Results: The PFOA group exhibited greater hip adduction at 30° (p=0.008), 45° (p=0.005), and 60° (p=0.008) knee flexion in the descending phase of the single-leg squat, as well as at 60° (p=0.009) and 45° (p=0.03) knee flexion in the ascending phase. No significant differences were found between groups for other kinematic variables (p>0.05). The PFOA group exhibited lower isometric hip abductor (p=0.02), extensor (p<0.001), and external rotator (p=0.007) torques. Conclusion: Individuals with PFOA exhibited excessive hip adduction that could increase stress on the lateral patellofemoral joint at 30°, 45°, and 60° knee flexion during the single-leg squat and exhibited weakness of the hip abductors, extensors, and external rotators in comparison to healthy controls. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Knee adduction moment and knee adduction angular impulse enlargement is the main biomechanical risk factor of knee osteoarthritis. According to the survey, a change in the foot progression angle could effectively change the motion mode of patients with knee osteoarthritis. However, the impact of toe-in and toe-out on knee adduction moment and knee adduction angular impulse in young and elderly patients did not reach a consensus. Therefore, this study comprehensively discussed the effect of foot progression angle on knee adduction moment and knee adduction angular impulse in different populations through meta-analysis and provided a reference for the treatment of knee osteoarthritis. METHODS: By June 2022, searches were conducted on Web of Science, EBSCO, PubMed and CNKI databases using “foot progression angle, knee adduction moment, knee adduction angular impulse, gait” as Chinese and English search terms. Self-controlled randomized controlled studies analyzing the effects of toein and toe-out on knee adduction moment bimodality and knee adduction angular impulse were included. The cochrane bias risk assessment tool was utilized to make a quality evaluation of the literature. Stata 15.1 software was used for subgroup analysis to determine the effect of foot progression angle on knee adduction moment and knee adduction angular impulse. Meta-regression analysis was used to further determine characteristics of outcome indicators (knee adduction moment, knee adduction angular impulse) changing with foot progression angle. RESULTS: (1) A total of 15 self-control trials and 2 randomized controlled trials (455 subjects) were included in the meta-analysis. All of the included articles were of medium to high quality. (2) The meta-analysis results showed that the toe-in gait could reduce the first peak of knee adduction moment (SMD=-0.380, 95%CI:-0.710 to -0.060, P=0.022) and knee adduction angular impulse (SMD=-1.470, 95%CI:-2.160 to -0.770, P < 0.001) in young patients. The toe-out gait reduced the second peak of knee adduction moment (SMD=-0.720, 95%CI:-1.010 to -1.440, P < 0.001) in young patients. In addition, toe-in gait could reduce the first peak of knee adduction moment in elder patients (SMD=-0.550, 95%CI:-0.800 to -0.300, P < 0.001), but increase the second peak knee adduction moment of elderly (SMD=0.280, 95%CI:-0.010 to 0.560, P=0.047). The toe-out gait could decrease the second peak knee adduction moment in this population (SMD=-0.510, 95%CI:-0.830 to -0.190, P=0.002). (3) Meta-regression showed that the greater the toe-out in elderly patients, the lower the second peak knee adduction moment. CONCLUSION: (1) Toe-in reduced the first peak knee adduction moment and knee adduction angular impulse in young knee osteoarthritis patients aged 18 to 34 years. Since knee adduction moment and knee adduction angular impulse were associated with medial knee loading and knee osteoarthritis incidence, toe-in gait intervention may be a suitable rehabilitation strategy for young patients. (2) Toe-in increased the second peak of knee adduction moment in older knee osteoarthritis patients over 60 years of age, which may exacerbate knee osteoarthritis in this population. However, the second peak of knee adduction moment during walking in this population decreases as the toe-out increases, contributing to a reduction in medial knee loading, suggesting that older patients may consider using toe-out gait during walking. [ABSTRACT FROM AUTHOR]

Soccer is played by a variety of individuals with varying abilities. The complicated lower limb movements involved within the game often lead to knee and ankle injuries, with anterior cruciate ligament injuries being the most severe with regard to rehabilitation time and ongoing health risks. This research explores the biomechanical kinematics of male and female soccer players on synthetic grass to determine whether trends in lower limb biomechanics over a variety of movements could explain injury risk. Both male and female players (n = 10) aged between 19 and 24 years performed running-based and stationary-start movements. Biomechanical measurements at the hip, knee, and ankle were recorded. Observations showed that specific differences in joint angles were largely dependent on the movements performed; however, for male players, on average, across all movements, 84.6% and 72.6% of the variation in joint angles could be explained by internal/external rotation at the hip and knee, respectively. For female players, internal/external knee rotation, as well as hip abduction and adduction, accounted for 83.6% and 80.2% of the variation in joint angles, respectively, across all the tested movements. This highlights the importance of hip mechanics and knee alignment for players when performing a variety of movements. [ABSTRACT FROM AUTHOR]

BACKGROUND: Strength differences between performance levels remain unclear in female football. Furthermore, the relationship between fulltime training and strength has been unexplored despite increased professionalisation in the sport. OBJECTIVE: The aims of this research were to examine knee flexor/extensor and hip adductor/abductor strength differences between elite and sub-elite female footballers, and then determine the relationship of strength performance to age, years of football experience (FE), and years of fulltime training (FTT). METHODS: 15 elite and 15 sub-elite professional female footballers were tested. The main outcomes were concentric isokinetic knee flexor and extensor peak moment at 60, 180, and 300 ∘ /s, and isometric hip adductor (ADD) and abductor (ABD) force. RESULTS: The elite team had higher absolute (300 ∘ /s: 47.13–49.33 Nm vs 37.33–38.93 Nm, p < 0.05) and normalised (300 ∘ /s: 0.76–0.80 Nm/kg vs 0.59–0.62 Nm/kg, p < 0.05) knee flexor values, and higher normalised ADD (5.64–5.66 N/kg vs 4.98–5.05 N/kg, p < 0.05) and ABD force (5.80–6.00 N/kg vs 5.26–5.39 N/kg, p < 0.05), compared to the sub-elite team. Age, FE, and FTT were correlated to knee flexor values (r = 0.381–0.559, p < 0.05). Additionally, FTT was correlated with normalised ADD and ABD force (r = 0.362–0.546, p < 0.05). CONCLUSION: Sub-elite female footballers may require additional knee flexor and hip strengthening in order to make the step up to the elite level. Those who are younger or have low FTT may also be recommended additional lower limb strengthening ahead of joining a fulltime training environment. [ABSTRACT FROM AUTHOR]

Purpose: Patient-specific alignment in total knee arthroplasty (TKA) has shown promising patient-reported outcome measures; however, the clinical and biomechanical effects of restoring the native knee anatomy remain debated. The purpose of this study was to compare the gait pattern between a mechanically aligned TKA cohort (adjusted mechanical alignment—aMA) and a patient-specific alignment TKA cohort (inverse kinematic alignment—iKA). Methods: At two years postoperatively, the aMA and iKA groups, each with 15 patients, were analyzed in a retrospective case–control study. All patients underwent TKA with robotic assistance (Mako, Stryker) through an identical perioperative protocol. The patients' demographics were identical. The control group comprised 15 healthy participants matched for age and gender. Gait analysis was performed with a 3D motion capture system (VICON). Data collection was conducted by a blinded investigator. The primary outcomes were knee flexion during walking, knee adduction moment during walking and spatiotemporal parameters (STPs). The secondary outcomes were the Oxford Knee Score (OKS) and Forgotten Joint Score (FJS). Results: During walking, the maximum knee flexion did not differ between the iKA group (53.0°) and the control group (55.1°), whereas the aMA group showed lower amplitudes of sagittal motion (47.4°). In addition, the native limb alignment in the iKA group was better restored, and although more in varus, the knee adduction moments in the iKA group were not increased (225 N mm/kg) compared to aMA group (276 N mm/kg). No significant differences in STPs were observed between patients receiving iKA and healthy controls. Six of 7 STPs differed significantly between patients receiving aMA and healthy controls. The OKS was significantly better in patients receiving iKA than aMA: 45.4 vs. 40.9; p = 0.05. The FJS was significantly better in patients receiving iKA than aMA: 84.8 vs. 55.5; p = 0.002. Conclusion: At two years postoperatively, the gait pattern showed greater resemblance to that in healthy controls in patients receiving iKA rather than aMA. The restoration of the native coronal limb alignment does not lead to increased knee adduction moments due to the restoration of the native tibial joint line obliquity. Level of evidence: Level III. [ABSTRACT FROM AUTHOR]

Background: Lateral wedge insoles (both standalone and those incorporating individualized arch support) have been frequently studied for the effects on knee joint loading and pain in people with knee osteoarthritis. It has been shown that many people who use these insoles do not obtain the intended biomechanical effect, and thus may not experience a clinical benefit. The ability to identify biomechanical responders to lateral wedge insoles before research or clinical intervention is an important objective for efficient resource use and optimizing patient outcomes. The purpose of our exploratory, hypothesis-generating study was to provide an initial assessment of variables that are associated with the biomechanical response to lateral wedge insoles in people with knee osteoarthritis. Methods: We collected a number of demographic (age, sex, body mass index, foot posture), clinical (knee pain, foot pain, radiographic disease severity), and walking-related (speed, knee alignment, frontal plane subtalar movement, and foot rotation) outcomes from 53 individuals with painful, radiographically-confirmed knee osteoarthritis. The walking-related outcomes were obtained using equipment both from the research laboratory and the clinical setting. We used logistic regression to generate predictive models to determine candidate variables associated with a reduction in the knee adduction moment during walking – a surrogate for tibiofemoral load distribution, and a known biomechanical risk factor for osteoarthritis progression – with the use of standalone and arch-supported lateral wedge insoles. Three different response thresholds (2%, 6%, and 10% reductions in the knee adduction moment) were used. Results: In general, biomechanical responders were those who walked faster, were female, had less varus alignment, and had less severe radiographic severity. Findings were similar between the standalone and arch-supported lateral wedge insoles, as well as between models using the laboratory-derived or clinically-available measures of walking performance. Conclusions: Our hypothesis-generating study provides valuable information that will inform future research into the efficient and effective use of lateral wedge insoles in the conservative management of knee osteoarthritis. [ABSTRACT FROM AUTHOR]

Introduction: Impaired hip kinematics and kinetics may incite patellar instability. This study tested the hypothesis that hip adduction and internal rotation angles during gait are higher in adolescents with recurrent patellar dislocations compared to healthy controls. Material and methods: Case–control study. Eighty-eight knees (67 patients) with recurrent patellar dislocation (mean age 14.8 years ± 2.8 SD) were compared to 54 healthy knees (27 individuals, 14.9 years ± 2.4 SD). Peak hip, knee and pelvis kinematics and kinetics were captured using 3D-gait analysis (VICON, 12 cameras, 200 Hz, Plug-in-Gait, two force plates) and compared between the two groups. One cycle (100%) consisted of 51 data points. The mean of six trials was computed. Results: Peak hip adduction angles and abduction moments were significantly higher in patients with recurrent patellar dislocation compared to the control group (p < 0.001 and 0.002, respectively). Peak internal hip rotation did not differ significantly. Conclusion: Elevated hip adduction angles and higher hip abduction moments in gait of adolescents with recurrent patellar dislocation may indicate an impaired function of hip abductors that contributes to patellar instability. [ABSTRACT FROM AUTHOR]

Introduction: Poliomyelitis has been considered a statutory notifiable infectious disease in Hong Kong since 1948. Approximately 15% to 80% of patients suffer from post-polio syndrome (PPS) with an increased risk of falling and chronic pain. Most of them relied on the use of knee lock-type orthoses as aids. This study aimed to evaluate the effect of using a custom-fit knee robotic orthosis on their gait performance. Materials and Methods: A case series report was used for this study on a group of individuals suffering from chronic PPS who used orthoses and had a history of falling. A knee robotic orthosis was custom-fit for eight sessions of walking practice. Assessments included laboratory gait analysis, functional measures, and subjective ratings of exertional level. Pain responses were recorded to evaluate the effect of using the knee robotic orthosis on participants' gait performance. Results: Five participants completed the study in using the knee robotic orthosis. All achieved reduction in shoulder tilting and trunk swaying movement on walking at the anterior-posterior and the medial-lateral direction. A total of 80% of the study participants achieved reduction in trunk rotation movement, lower-limb circumduction, and hip hiking movement on the affected side on walking. All study participants were able to demonstrate improvement in their gait symmetry after using the knee robotic orthosis as reflected by the symmetric index improvement of kinematics. The rate of perceived exertion and the visual analog scale of pain in all study participants were reported lower when they used the knee robotic orthosis. However, the 10-m walking time achieved was longer. Conclusions: The knee robotic orthosis had a positive effect on remediating the abnormal kinematics of PPS patients using conventional lock-knee orthosis after eight sessions of training practice. Reduction in the limping gait pattern and improvement in gait symmetry was achieved in using a knee robotic orthosis for walking. The chronic pain response and the physical exertional level on walking were also reduced. However, the walking speed achieved was slower. Clinical Relevance: The application of the knee robotic orthosis for walking assist is new to most of the PPS patients. The positive outcomes achieved merit further research for future clinical practice. [ABSTRACT FROM AUTHOR]

Context: Excessive knee valgus on landing can cause anterior cruciate ligament injury. Therefore, knee valgus alignment may show characteristic energy absorption patterns during landings with lateral movement that impose greater impact forces on the knee joint compared with landings in other alignments. Objective: To investigate the energy absorption strategy in lower-extremities during side steps in females with knee valgus alignment. Design: Controlled laboratory study. Setting: University research laboratory. Participants: A total of 34 female college students participated in this experiment. Interventions: Participants performed single-leg drop vertical jump and side steps. All participants were divided into valgus (n = 13), neutral (n = 9), and varus (n = 12) groups according to knee position during landing in single-leg drop vertical jumps. Main Outcome Measures: Lower-extremity joint angles, moments, and negative works were calculated during landing in side steps, and 1-way analysis of variance and post hoc tests were used to determine between-group differences. Results: Negative works of hip extensors, knee abductors, and ankle plantar flexors during landing in side steps were significantly smaller in the valgus than in the varus group; however, negative work of the knee extensors was significantly greater in the valgus group than in varus group. Conclusions: The findings of this study indicated that landing with knee valgus induced the characteristic energy absorption strategy in the lower-extremity. Knee extensors contributed more to energy absorption when landing in knee valgus than in knee varus alignment. Learning to land in knee varus alignment might reduce the impact on the knee joint by increasing the energy absorption capacities of hip extensors, knee abductors, and ankle plantar flexors. [ABSTRACT FROM AUTHOR]

Background: Aim of the observational study was to assess which of the gait and balance parameters are most affected in Parkinson-plus syndromes patients with falling tendencies as compared to healthy individuals. Methods: Authors studied levodopa-responsive patients of multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) who had falling tendencies early in the disease and healthy controls and evaluated the spatiotemporal gait parameters using BTS G WALK and balance parameters by Limits of Stability test on BIODEX Balance system SD in the Gait and Motion Analysis Lab. Results: In comparison to controls, Parkinson-plus syndromes patients had significantly different gait and balance parameters, apart from stride time and stance time, pelvic obliquity and pelvic tilt, cadence, hip abduction–adduction and hip rotation, foot progression, gait profile score, gait variable hip abduction–adduction, rotation, gait variable flexion–extension and gait deviation index (p-values < 0.05). Also, in comparison to MSA patients, PSP patients had significantly greater values of all static parameters except for swing time, step width, pelvic tilt and rotation, hip rotation and ankle dorsiflexion-plantarflexion, gait profile score of right limbs and all gait variable parameters except for pelvic tilt and hip flexion–extension, foot progression and gait deviation index of right limb. However, balance parameters were similar in MSA and PSP. Duration of disease and duration since falls may not significantly affect gait and balance parameters in Parkinson-plus syndromes patients. Conclusions: Hence, gait differentiates between Parkinson-plus patients and healthy controls and between MSA and PSP patients with falling tendencies and gait and balance parameters may also help in planning rehabilitative strategies. [ABSTRACT FROM AUTHOR]

Clinicians frequently assess asymmetry in strength, flexibility, and performance characteristics as a method of screening for potential musculoskeletal injury. The identification of asymmetry in countermovement jumps may be an ideal method to reveal asymmetry in other lower extremity characteristics such as strength that otherwise may require additional testing, potentially reducing the time and burden on both the athlete and clinicians. The present study aims to examine the ability of asymmetry in both the single-leg and two-leg countermovement jump tests to accurately detect hip abduction, hip adduction, and eccentric hamstring strength asymmetry. Fifty-eight young male elite soccer players from the same professional academy performed a full battery of functional performance tests which included an assessment of hip adductor and abductor strength profiles, eccentric hamstring strength profiles, and neuromuscular performance and asymmetries during countermovement jumps. Bilateral variables attained from both the single-leg and two-leg countermovement jump tests included concentric impulse (Ns), eccentric mean force (N), and concentric mean force (N) computed by the VALD ForceDecks software. Average maximal force (N) was calculated bilaterally for the strength assessments. Asymmetry was calculated for each variable using 100 × |(right leg − left leg)/(right leg)| and grouped into three categories: 0 to <10%, 10% to <20%, and 20% or greater. Analyses were performed for the two higher asymmetry groups. The accuracy to detect strength asymmetry was assessed as the sensitivity, specificity, and predictive values for positive and negative tests. The outcomes from the accuracy assessments suggest that the single-leg countermovement jump concentric impulse variable at the 20% threshold is indicative of a youth male soccer player having hip adduction strength asymmetry while also demonstrating more accuracy and applicability than the two-leg countermovement jump concentric impulse variable. [ABSTRACT FROM AUTHOR]

Background: High tibial osteotomy (HTO) reduces the load distribution of the medial compartment by modifying leg alignment. Knee adduction moment (KAM), a surrogate measure of dynamic loading in the knee joint, decreases after HTO. However, leg alignment does not fully account for KAM. Purpose: To assess the association between the pelvis-knee-ankle angle (PKA), a novel radiographic parameter reflecting leg alignment and pelvic width, and KAM and patient-reported outcomes after HTO. Study Design: Cross sectional study; Level of evidence, 3. Methods: PKA is the angle between the line from the midpoint of the anterior superior iliac spine to the center of the knee joint and the mechanical axis of the tibia. In this study, 54 patients with medial compartment knee osteoarthritis and varus alignment who underwent 3-dimensional gait analysis preoperatively and 2 years after medial open-wedge HTO were evaluated. The primary outcomes were hip-knee-ankle angle (HKA), PKA, KAM peaks, and Knee Society Score (KSS). Single and multivariate regression analysis including PKA and KAM peaks as well as other demographic and radiologic factors was performed. Results: HKA was weakly correlated with the first peak KAM (r = −0.33; P <.01) and second peak KAM (r = −0.27; P =.01) before HTO, but not significantly correlated after HTO. PKA was moderately correlated with the first peak KAM (r = 0.45; P <.01) and second peak KAM (r = 0.45; P <.01) before HTO and with the first peak KAM (r = 0.51; P <.01) and second peak KAM (r = 0.56; P <.01) after HTO. Multivariate linear regression revealed that postoperative PKA was still associated with the KAM peaks after HTO. Only postoperative PKA was correlated with the KSS satisfaction subscale (r = −0.30; P =.03). Conclusion: Although HKA was not correlated with KAM peaks after HTO, PKA was significantly correlated with KAM peaks in patients with varus knee osteoarthritis after HTO. [ABSTRACT FROM AUTHOR]

Using insoles to modify walking biomechanics is of keen interest for the treatment of medial-compartment knee osteoarthritis. So far, insole interventions have focused on reducing the peak of the knee adduction moment (pKAM) and have led to inconsistent clinical outcomes. This study aimed to evaluate the changes in other gait variables related to knee osteoarthritis when patients walk with different insoles to provide insights into the necessity to enlarge the biomechanical analyses to other variables. Walking trials were recorded for 10 patients in four insole conditions. Changes among conditions were computed for six gait variables, including the pKAM. The associations between the changes in pKAM and the changes in the other variables were also assessed individually. Walking with different insoles had noticeable effects on the six gait variables, with high heterogeneity among patients. For all variables, at least 36.67% of the changes were of medium-to-large effect size. The associations with the changes in pKAM varied among variables and patients. In conclusion, this study showed that varying the insole could globally influence ambulatory biomechanics and that limiting measurement to the pKAM could lead to an important loss of information. Beyond the consideration of additional gait variables, this study also encourages personalized interventions to address inter-patient variability. [ABSTRACT FROM AUTHOR]

BACKGROUND: The most commonly used approach for total knee arthroplasty is the medial parapatellar approach, but due to its damage to the quadriceps tendon, it may lead to the weakening of the extensor device in the later stage, thus affecting the long-term functional recovery of patients.OBJECTIVE: To evaluate the advantage of total knee arthroplasty with medial pivot prosthesis through medial subvastus approach. METHODS: Patients with unilateral knee osteoarthritis who underwent total knee arthroplasty with medial pivot prosthesis from August 2018 to October 2019 were enrolled in this study. Of them, 26 patients received medial subvastus approach and 27 patients received medial parapatellar approach. There were no significant differences in age, sex distribution, body mass index, preoperative hemoglobin, visual analogous scale pain score, knee joint score of Hospital for Special Surgery, and knee range of motion between the two groups (P > 0.05). The operative incision length, operative time, the first postoperative straight leg raising time, the first postoperative activity time out of bed and the postoperative hospitalization time were compared and analyzed between the two groups. Postoperative visual analogous scale pain score, knee Hospital for Special Surgery score, and range of motion of the knee joint were evaluated in both groups. RESULTS AND CONCLUSION: (1) The mean incision length, the first postoperative straight leg elevation time, the first postoperative movement time, and the postoperative hospitalization time in the medial subvastus approach group were significantly shorter than those in the medial parapellar approach group (P < 0.05). There was no significant difference in the operative time between the two groups (P > 0.05). (2) At 2 days after surgery, the visual analogous scale pain score in the medial subvastus approach group was significantly lower than that in the medial parapatellar approach group (P < 0.001). At 1 month after operation, there was no significant difference in visual analogous scale pain scores between the two groups (P = 0.474). (3) The knee Hospital for Special Surgery score of patients in the medial subvastus approach group was significantly higher than that in the medial parapellar approach group at 1 and 3 months after surgery (P < 0.001). At 1 year after surgery, there was no significant difference in knee Hospital for Special Surgery score between the two groups (P=0.656). (4) At 1 month after surgery, the range of motion of knee joint in the medial subvastus approach group was significantly higher than that in the medial parapatellar approach group (P < 0.001). At 3 months and 1 year after surgery, there was no significant difference in the range of motion of knee joint between the two groups (P=0.298, P=0.999). (5) The use of medial subvastus approach for total knee arthroplasty does not damage the medial vastus tendon, and the extensor device is retained, which is convenient for the installation of medial pivot prosthesis and intraoperative evaluation of medial pivot movement. It can significantly improve the pain and swelling of the limb after operation and effectively promote the early functional exercise. [ABSTRACT FROM AUTHOR]

One of the recommendations for individuals with knee osteoarthritis (OA) is the use of specific footwear, such as sturdy or cushioned shoes. However, the long-term use effects of using cushioned shoes on the pain and spatiotemporal gait parameters in individuals with knee OA are yet to be reported. We therefore aimed to compare the efficacy of cushioned sport footwear versus sham shoes on motor functions, pain and gait characteristics of individuals with knee OA who used the shoes for 3 months. In a double-blinded study, we provided 26 individuals with knee OA with cushioned sport shoes and 12 individuals with knee OA with similar sport shoes without cushioning for 3 months. The gait analysis, the timed up and go (TUG) test and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) were conducted and the pain levels were measured at the baseline, 1 month, and 3 months after the baseline. We found that the cushioned shoes reduce the amount of pain (based on WOMAC) in the affected knee and increase functionality in the research group, but not in the control group. Gait velocity and cadence were increased in both groups. Gait spatiotemporal parameters and their symmetry were unaffected during the intervention. We conclude that the use of cushioned shoes should be recommended to individuals with knee OA for alleviating pain. [ABSTRACT FROM AUTHOR]

This study examined the effects of obesity on cartilage mechanics and longitudinal failure probability at the medial tibiofemoral compartment, using combined musculoskeletal simulation and probabilistic failure modelling approaches. The current investigation examined twenty obese females (BMI > 30.0 kg/m2) and 20 healthy weight (BMI < 25.0 kg/m2) females. Walking kinematics were obtained via an 8-camera optoelectric system, and a force plate was used to collect ground reaction forces. Musculoskeletal simulation and probabilistic failure modelling were utilized to explore medial tibiofemoral forces and cartilage probability. Comparisons between groups were undertaken using linear mixed-effects models. Net peak cartilage forces, stress and strain were significantly larger in the obese group (force = 2013.92 N, stress = 3.03 MPa & strain = 0.25), compared to health weight (force = 1493.21 N, stress 2.26 MPa & strain = 0.19). In addition, medial tibiofemoral cartilage failure probability was also significantly larger in the obese group (42.98%) compared to healthy weight (11.63%). The findings from the current investigation show that obesity has a profoundly negative influence on longitudinal medial knee cartilage health and strongly advocates for the implementation of effective weight management programs into long-term musculoskeletal management strategies. [ABSTRACT FROM AUTHOR]

To date there is a paucity of information about how different types of conventional running shoes influence lower limb kinematics. The aim of the study was to determine the influence of motion control, neutral, and cushioned running shoes upon lower limb kinematics. Twenty-eight active males completed one test session running in standardized motion control, neutral, and cushioned running shoes on a treadmill at a self-selected pace (2.9 [0.6] m·s−1). Kinematic data were collected using a VICON motion analysis system with hip, knee, and ankle joint angles calculated. Discrete parameters associated with stance phase kinematics were compared between footwear conditions. Significant (P <.05) differences in knee flexion and internal rotation at toe off, and knee adduction range of motion were reported between footwear conditions. Significant (P <.05) differences in ankle joint dorsiflexion and adduction upon initial contact, peak dorsiflexion, eversion and abduction, and inversion at toe off were reported between footwear conditions. The influence of motion control, neutral, and cushioned running shoes on joint function dissipates moving proximally, with larger changes reported at the ankle compared with knee and hip joints. Although significant differences were reported between footwear conditions, these changes were of a small magnitude and effect size. [ABSTRACT FROM AUTHOR]

Gait alterations in those with mild unilateral knee pain during walking may provide clues to modifiable alterations that affect progression of knee pain and osteoarthritis (OA). To examine this, we applied machine learning (ML) approaches to gait data from wearable sensors in a large observational knee OA cohort, the Multicenter Osteoarthritis (MOST) study. Participants completed a 20-m walk test wearing sensors on their trunk and ankles. Parameters describing spatiotemporal features of gait and symmetry, variability and complexity were extracted. We used an ensemble ML technique ("super learning") to identify gait variables in our cross-sectional data associated with the presence/absence of unilateral knee pain. We then used logistic regression to determine the association of selected gait variables with odds of mild knee pain. Of 2066 participants (mean age 63.6 [SD: 10.4] years, 56% female), 21.3% had mild unilateral pain while walking. Gait parameters selected in the ML process as influential included step regularity, sample entropy, gait speed, and amplitude dominant frequency, among others. In adjusted cross-sectional analyses, lower levels of step regularity (i.e., greater gait variability) and lower sample entropy(i.e., lower gait complexity) were associated with increased likelihood of unilateral mild pain while walking [aOR 0.80 (0.64–1.00) and aOR 0.79 (0.66–0.95), respectively]. [ABSTRACT FROM AUTHOR]

This study aimed to compare a biaxial ankle-foot orthosis (AFO) with a lateral wedge insole in terms of the biomechanical and clinical outcomes in individuals with knee osteoarthritis. A cross-over randomized design was used where 31 individuals (25 females and six males, mean age of 52.19 ± 4.12 years) with knee osteoarthritis wore each intervention for two weeks with two weeks washout period. Three-dimensional kinematic and kinetic data and clinical outcomes were collected to evaluate the effects of each intervention on knee adduction moment (KAM), pain, stiffness, and function. Both orthoses significantly improved pain by 17 and 22%, function by 11 and 14%, the first peak KAM by 15.7 and 19.2%, the second peak KAM by 10.4 and 16.7%, and KAM impulse by 14.8 and 22.2%, respectively. However, the biaxial AFO significantly reduced the KAM and improved function compared to the lateral wedge insole (p < 0.01). The results of this study have shown that both orthoses have a potential role in the conservative management of medial knee osteoarthritis. The biaxial AFO proved statistically better at improving function and KAM; though these differences do not seem to be clinically significant. Orthotic interventions have been reported to be effective in the management of medial knee osteoarthritis. Lateral wedge insole and biaxial ankle-foot orthosis (AFO) are effective in the improvement of pain, function, and knee adduction moment (KAM) in people with medial knee osteoarthritis. The biaxial AFO, compared with lateral wedge insole, contributes to statistically more improvement of function and KAM. However, these differences do not seem to be clinically significant. [ABSTRACT FROM AUTHOR]

The inertial measurement unit (IMU)-to-segment (I2S) alignment is an important part of IMU-based joint angle estimation, and the accurate estimation of the three degree of freedom (3-DOF) knee angle can provide practical support for the evaluation of motions. In this paper, we introduce a dynamic weight particle swarm optimization (DPSO) algorithm with crossover factor based on the joint constraint to obtain the dynamic alignment vectors of I2S, and use them to perform the quaternion-based 3-DOF knee angle estimation algorithm. The optimization algorithm and the joint angle estimation algorithm were evaluated by comparing with the optical motion capture system. The range of 3-DOF knee angle root mean square errors (RMSEs) is 1.6°–5.9° during different motions. Furthermore, we also set up experiments of human walking (3 km/h), jogging (6 km/h) and ordinary running (9 km/h) to investigate the effects of dynamic I2S misalignment errors on 3-DOF knee angle estimation during different motions by artificially adding errors to I2S alignment parameters. The results showed differences in the effects of I2S misalignment errors on the estimation of knee abduction, internal rotation and flexion, which indicate the differences in knee joint kinematics among different motions. The IMU to thigh misalignment error has the greatest effect on the estimation of knee internal rotation. The effect of IMU to thigh misalignment error on the estimation of knee abduction angle becomes smaller and then larger during the two processes of switching from walking to jogging and then speeding up to ordinary running. The effect of IMU to shank misalignment error on the estimation of knee flexion angle is numerically the largest, while the standard deviation (SD) is the smallest. This study can provide support for future research on the accuracy of 3-DOF knee angle estimation during different motions. [ABSTRACT FROM AUTHOR]

Backward walking (BW) has been recommended as a rehabilitation intervention to prevent, manage, or improve diseases. However, previous studies showed that BW significantly increased the first vertical ground reaction force (GRF) during gait, which might lead to higher loading at the knee. Published reports have not examined the effects of BW on medial compartment knee loading. The objective of this study was to investigate the effects of BW on external knee adduction moment (EKAM). Twenty-seven healthy adults participated in the present study. A sixteen-camera three-dimensional VICON gait analysis system, with two force platforms, was used to collect the EKAM, KAAI, and other biomechanical data during BW and forward walking (FW). The first (P < 0.001) and second (P < 0.001) EKAM peaks and KAAI (P = 0.02) were significantly decreased during BW when compared with FW. The BW significantly decreased the lever arm length at the first EKAM peak (P = 0.02) when compared with FW. In conclusion, BW was found to be a useful strategy for reducing the medial compartment knee loading even though the first peak ground reaction force was significantly increased. [ABSTRACT FROM AUTHOR]

The proprioceptive neuromuscular facilitation (PNF) techniques such as contract-relax-antagonist-contract and contract-relax have been adopted by the researchers in the clinical area to investigate their efficacy on hemiplegic patient. This study investigated 4-week PNF exercise on the gait impaired hemiplegic participants measured with the Visual gait assessment scale-a 3 sectioned scale. Fourteen male and six female hemiplegic gait impaired participants (mean age 49.1 ± 7.8 years) were recruited into the study and treated for PNF protocol twice a day for 4 weeks. In the swing phase participants shows having decreased internal rotation (25%) and adduction (25%) and increased external rotation (47.5%) and abduction (42.5%) in hip and pelvis, normal knee movement (42.5%), and normal ankle/foot movement (12.5%) in the 4th week of intervention. In the stance phase, the participants show having decreased internal rotation (27.5%) and adduction (32.5%), increased external rotation (40%), abduction (42.5%) in hip and pelvis, normal knee movement (10%), normal ankle/foot movement (50%) in the 4th week of intervention. In the late stance phase, the participants show having decreased internal rotation (30%) and adduction (25%), increased external rotation (30%) and abduction (27.5%) in hip and pelvis, normal knee movement (32.5%) and normal ankle/foot movement (55%) in the 4th week of intervention. It has been seen, there is a significant change in excessive internal rotation, excessive external rotation, excessive abduction, excessive adduction, knee movement, and the ankle/foot movement i.e., p= <0.05. PNF exercise is an effective, easy to apply and potentially risk-free intervention for hemiplegic patients after stroke patients. [ABSTRACT FROM AUTHOR]

(1) Background: Knee osteoarthritis (OA) is a serious orthopedic problem. In this context, the high tibial osteotomy (HTO) is an established surgical procedure to reduce the load and degeneration of the affected compartment. The aim of this investigation was to judge standing steadiness and asymmetry, pain intensity and quality of life among patients who underwent HTO surgery. (2) Methods: Twenty-five male patients with medial tibiofemoral OA finished this 2 year follow-up study. Standing balance was captured using force plates with four uniaxial sensors before, 6 weeks after, 1 year after, and 2 years after HTO surgery. The percentage weight (PW) under the foot at one side, the stability (ST) index and the weight distribution (WD) index were the main outcomes. Comparisons were conducted using repeated measures analyses of variance. (3) Results: Over time, the PW under the foot at the HTO side increased on average (p < 0.001). In terms of standing steadiness, the average ST remained similar over the time points (p = 0.71). The WD index was affected by time (p = 0.003). (4) Conclusions: In order to judge short-term effects, the PW is recommended, whereas long-term effects can be identified either through the PW or the WD index. [ABSTRACT FROM AUTHOR]

Given its apparent representation of cumulative (vs peak) loads, this feasibility study investigates vertical ground reaction impulse (vGRI) as a real-time biofeedback variable for gait training aimed at reducing lower limb loading. Fifteen uninjured participants (mean age = 27 y) completed 12 2-min trials, 1 at each combination of 4 walking speeds (1.0, 1.2, 1.4, and 1.6 m/s) and 3 targeted reductions in vGRI (5, 10, and 15%) of the assigned ("target") limb, with the latter specified relative to an initial baseline (no feedback) condition at each speed. The ability to achieve targeted reductions was assessed using step-by-step errors between measured and targeted vGRI. Mean (SD) errors were 5.2% (3.7%); these were larger with faster walking speeds but consistent across reduction targets. Secondarily, we evaluated the strategy used to modulate reductions (ie, stance time or peak vertical ground reaction force [vGRF]) and the resultant influences on knee joint loading (external knee adduction moment [EKAM]). On the targeted limb, stance times decreased (P < .001) with increasing reduction target; first and second peaks in vGRF were similar (P > .104) across all target conditions. While these alterations did not significantly reduce EKAM on the target limb, future work in patients with knee pathologies is warranted. [ABSTRACT FROM AUTHOR]

This study investigated the effect of a handball-specific fatigue protocol on hip and knee kinematics. Twenty female handball athletes performed three trials of the single-leg landing (SLL), sidestep cutting manoeuvre (SCM), and drop vertical jump (DVJ) before and after the fatigue protocol. Knee and hip angle waveforms were compared using statistical parametric mapping (p < 0.05). During the SLL, the fatigue increased hip adduction (4–7% cycle) and knee abduction (4–9% and 25–27%). For the SCM, hip flexion was reduced under fatigue during 14–29% and 44–68% of the cycle. Similarly, the knee flexion decreased between 7–36% and 53–73%. Besides, during the fatigue state, the athletes reduced the hip abduction between 0–11% of the cycle and increased the knee abduction between 20–23%. During the DVJ task, when fatigued, the hip flexion decreased between 19–44% of the cycle and the knee flexion between 1–16% and 18–77%. The fatigue protocol altered the lower limb kinematics, decreasing knee and hip flexions during the SCM and DVJ and increasing the knee valgus during both single-leg landing tasks. [ABSTRACT FROM AUTHOR]

The knee unloader brace can change loading on knee which may be effective in reducing symptoms and progression of disease in people with knee osteoarthritis. The purpose of this study was to evaluate the effect of a new knee brace during walking in a patient with medial compartment knee osteoarthritis. Two brace types were used: new brace and conventional brace. A pneumatic cuff of novel brace was fitted in the bottom of the medical slipper that was connected to the cuff section of the knee through the tube. After the knee brace is deployed, its force can vary in different stages of the gait. During the heel strike, the weight of the cuff is compressed on the floor, causing the air to flow inside it and entering the volume of air into the knee pad. The results of using this pneumatic knee brace compared with conventional knee braces on a patient showed that in both cases, the open and closed palatal pump, the adduction moment and ROM was decreased in the stance phase. But the three-point knee pressure, however, was less effective in reducing the adduction moment but also reduced the knee ROM. Using novel brace can eliminate the patient's need for painful and costly surgery to reduce the symptoms of osteoarthritis. [ABSTRACT FROM AUTHOR]

This study aimed to determine the effects of zoledronic acid (ZOL) on OA in rats and explored the molecular mechanism of osteoclast activation in early OA. A knee OA rat model was designed by surgically destabilizing the medial meniscus (DMM). Seventy-two male rats were randomly assigned to Sham+phosphate-buffered saline (PBS), DMM+PBS, and DMM+ZOL groups; rats were administered with 100 μg/Kg ZOL or PBS, twice weekly for 4 weeks. After 2, 4, 8, and 12 weeks of OA induction, the thickness of the hyaline and calcified cartilage layers was calculated using hematoxylin and eosin staining, degenerated cartilage stained with Safranin O-fast green staining was evaluated and scored, tartrate-resistant acid phosphatase (TRAP)-stained osteoclasts were counted, changes in subchondral bone using micro-computed tomography were analyzed, and PINP and CTX-I levels were detected using enzyme-linked immunosorbent assay. Using these results, 18 male rats were randomly assigned to three groups. Four weeks after surgery, Wnt5a, RANKL, CXCL12, and NFATc1 protein levels were measured in subchondral bone using western blotting, and mRNA levels of genes related to osteoclastogenesis in subchondral bone were measured using quantitative polymerase chain reaction. Bone marrow-derived macrophages were isolated as osteoclast precursors, and cell differentiation, migration, and adhesion were assessed by TRAP staining and Transwell assays, revealing that DMM induced knee OA in rats. Progressive cartilage loss was observed 12 weeks after OA induction. Subchondral bone remodeling was dominated by bone resorption during early OA (within 4 weeks), whereas bone formation was increased 8 weeks later. ZOL suppressed bone resorption by inhibiting Wnt5a signaling in early OA, improved the imbalance of subchondral bone remodeling, reduced cartilage degeneration, and delayed OA progression. Additionally, ZOL delayed OA progression and reduced cartilage degeneration via a spatiotemporal effect in DMM-induced OA. Osteoclast activity in early OA might be associated with Wnt5a signaling, indicating a possible novel strategy for OA treatment. [ABSTRACT FROM AUTHOR]

Background: Previous investigations on valgus knee bracing have mostly used the external knee adduction moment. This is a critical limitation, as the external knee adduction moment does not account for muscle forces that contribute substantially to the medial tibiofemoral contact force (MTCF) during walking. The aims of this pilot study were to: 1) determine the effect of a valgus knee brace on MTCF; 2) determine whether the effect is more pronounced after 8 weeks of brace use; 3) assess the feasibility of an 8-week brace intervention. Methods: Participants with medial radiographic knee OA and varus malalignment were fitted with an Össur Unloader One© brace. Participants were instructed to wear the brace for 8 weeks. The MTCF was estimated via an electromyogram-assisted neuromuscular model with and without the knee brace at week 0 and week 8. Feasibility outcomes included change in symptoms, quality of life, confidence, acceptability, adherence and adverse events. Results: Of the 30 (60% male) participants enrolled, 28 (93%) completed 8-week outcome assessments. There was a main effect of the brace (p<0.001) on peak MTCF and MTCF impulse, but no main effect for time (week 0 and week 8, p = 0.10), and no interaction between brace and time (p = 0.62). Wearing the brace during walking significantly reduced the peak MTCF (-0.05 BW 95%CI [-0.10, -0.01]) and MTCF impulse (-0.07 BW.s 95%CI [-0.09, -0.05]). Symptoms and quality of life improved by clinically relevant magnitudes over the 8-week intervention. Items relating to confidence and acceptability were rated relatively highly. Participants wore the brace on average 6 hrs per day. Seventeen participants reported 30 minor adverse events over an 8-week period. Conclusion: Although significant, reductions in the peak MTCF and MTCF while wearing the knee brace were small. No effect of time on MTCF was observed. Although there were numerous minor adverse events, feasibility outcomes were generally favourable. Trial registration: Australian and New Zealand Clinical Trials Registry (12619000622101). [ABSTRACT FROM AUTHOR]

Background. Valgus braces are prescribed as a common conservative treatment option for patients with medial gonarthrosis to improve their quality of life. Many studies had reviewed the effects of the valgus braces on patients with medial gonarthrosis, while they mainly focused on the knee adduction moment (KAM), with less attention paid to other parameters such as spatiotemporal and morphological parameters. Objectives. The purpose of this study was to review the effects of valgus braces on the spatiotemporal, kinematic/kinetic, morphological, and muscle parameters. Methods. Based on the selected keywords, a survey of literatures was performed in Web of Science, PubMed, Scopus, and Google Scholar using the PRISMA methods, and the search period was established from January 2000 to March 2022. Results. Thirty-four articles were included. According to the conclusion of these articles, the valgus brace can be used to relieve the symptoms of patients with medial gonarthrosis by decreasing the varus angle, decreasing the KAM, and redistributing the knee compartment loads. However, the effects of valgus braces on other biomechanical parameters (e.g., walking speed, cadence, joint angle, and joint space) had not reached a consensus. Conclusions. The valgus knee brace can effectively relieve the symptoms of medial gonarthrosis through multiple mechanisms, while there is still some confusion about the effectiveness of the valgus brace on the other biomechanical parameters. [ABSTRACT FROM AUTHOR]

Knee osteoarthritis is a progressive disease mediated by high joint loads. Foot progression angle modifications that reduce the knee adduction moment (KAM), a surrogate of knee loading, have demonstrated efficacy in alleviating pain and improving function. Although changes to the foot progression angle are overall beneficial, KAM reductions are not consistent across patients. Moreover, customized interventions are time-consuming and require instrumentation not commonly available in the clinic. We present a regression model that uses minimal clinical data—a set of six features easily obtained in the clinic—to predict the extent of first peak KAM reduction after toe-in gait retraining. For such a model to generalize, the training data must be large and variable. Given the lack of large public datasets that contain different gaits for the same patient, we generated this dataset synthetically. Insights learned from a ground-truth dataset with both baseline and toe-in gait trials (N = 12) enabled the creation of a large (N = 138) synthetic dataset for training the predictive model. On a test set of data collected by a separate research group (N = 15), the first peak KAM reduction was predicted with a mean absolute error of 0.134% body weight * height (%BW*HT). This error is smaller than the standard deviation of the first peak KAM during baseline walking averaged across test subjects (0.306%BW*HT). This work demonstrates the feasibility of training predictive models with synthetic data and provides clinicians with a new tool to predict the outcome of patient-specific gait retraining without requiring gait lab instrumentation. Author summary: Gait retraining is a conservative intervention for knee osteoarthritis shown to reduce pain and improve function. Although customizing a treatment plan for each patient results in a better therapeutic response, customization cannot yet be performed outside of the gait laboratory, preventing research advances from becoming part of clinical practice. Our work aimed to build a model that accurately predicts whether a patient with knee osteoarthritis will benefit from non-invasive gait retraining using measures that can be easily collected in the clinic. To overcome the lack of large datasets required to train predictive models, we generated data synthetically (N = 138) based on limited ground-truth examples, and we provide experimental evidence for the model's ability to generalize to real data (N = 15). Our results contribute toward a future in which clinicians can use data collected in the clinic to easily identify patients who would respond to therapeutic gait retraining. [ABSTRACT FROM AUTHOR]

No objective criteria exist for progressing athletes into cutting manoeuvres following ACL reconstruction (ACLR). The purpose of this study was to evaluate the relationship between a jump-cut task (JC) and the single-limb squat (SLS) in both ACLR and healthy controls. Case-control, laboratory based. Twenty-three participants with a history of ACLR (Age = 21 ± 3 years; Height = 174.5 ± 7.2 cm; Mass = 76.2 ± 9.9 kg) and 23 healthy controls participants (Age = 21 ± 3 years; Height = 173.8 ± 9.2 cm; Mass = 75.0 ± 10.5 kg) were included. Kinematics were collected bilaterally. Correlations between tasks were evaluated for kinematics. Independent sample t-tests were used to evaluate differences between groups for each dependent variable. Peak trunk rotation and medial knee displacement were strongly correlated (p < 0.001, r2 = 0.63), between tasks. ACLR group performed SLS and JC tasks with less sagittal plane motion compared to healthy controls (p < 0.05). Lack of frontal and transverse plane control during SLS resulted in positions of increased lateral trunk flexion, hip adduction, and medial knee displacement during JC. The SLS may be considered for use as a clinical predictor of JC during rehabilitation following ACLR. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients with mild knee osteoarthritis are prone to induce pain and aggravation of arthritis during daily gait walking. At present, the changes in the biomechanical behavior of the internal knee joints of such patients under the gait flexion angle are not very clear. There are few reports in the literature. OBJECTIVE: Based on the proven finite element model of the mild osteoarthritis knee joint, according to the change of gait cycle and knee flexion angle, to simulate the knee flexion behavior at four angles of 0°, 10°, 20°, and 30°, and to study the stress distribution characteristics and contact area changes of femoral cartilage, tibial cartilage, and meniscus. METHODS: The material properties of the finite element model of the mild osteoarthritis knee joint were defined. The boundary conditions and the axial load were determined under different knee flexion angles. By analyzing the Mises stress, Tresca stress, and contact area of the non-bone tissue in the tibiofemoral joint, the biomechanical behavior changes inside the knee joint were studied. RESULTS AND CONCLUSION: The results of finite element analysis showed that as the knee flexion angle increased, the peak Mises stress and the peak Tresca stress on the meniscus, femoral cartilage, and tibial cartilage showed a relatively increasing trend. The total contact area of the tibiofemoral joint showed a decreasing trend, and the medial meniscus subluxation caused the lateral peak to be larger than the medial peak. Meanwhile, the contact area of the medial compartment decreased and the contact area of the lateral compartment increased. When the knee flexion angle reached 20° and 30°, the peak of Mises stress and the peak of Tresca stress appeared. Results showed that when the knee flexion angle of the mild osteoarthritis knee joint changed, the internal stress and contact area change characteristics changed because of the medial meniscus subluxation. The medial contact area decreased; the peak stress increased; and the lateral contact area increased. The peak stress increased and the increase was greater than the inside. The breakdown of the internal load balance of the joint may increase the risk of articular cartilage degeneration and promote the aggravation of knee osteoarthritis. [ABSTRACT FROM AUTHOR]

This study aimed to identify the clinical and biomechanical factors of subjects with excessive foot pronation who are not responsive (i.e., "non-responders") to medially wedged insoles to increase knee adduction external moment. Ankle dorsiflexion range of motion, forefoot-shank alignment, passive hip stiffness, and midfoot passive resistance of 25 adults with excessive bilateral pronation were measured. Also, lower-limb angles and external moments were computed during walking with the participants using control (flat surface) and intervention insoles (arch support and 6° medial heel wedge). A comparison between "responders" (n = 34) and "non-responders" (n = 11) was conducted using discrete and continuous analyses. Compared with the responders, the non-responders had smaller forefoot varus (p = 0.014), larger midfoot passive internal torque peak (p = 0.005), and stiffness measured by the torsimeter (p = 0.022). During walking, non-responders had lower angle peaks for forefoot eversion (p = 0.001), external forefoot rotation (p = 0.037), rearfoot eversion (p = 0.022), knee adduction (p = 0.045), and external hip rotation (p = 0.022) and higher hip internal rotation angle peak (p = 0.026). Participants with small forefoot varus alignment, large midfoot passive internal torque, stiffness, small knee valgus, hip rotated internally, and foot-toed-in during walking did not modify the external knee adduction moment ("non-responders"). Clinicians are advised to interpret these findings with caution when considering the prescription of insoles. Further investigation is warranted to fully comprehend the response to insole interventions among individuals with specific pathologies, such as patellofemoral pain and knee osteoarthritis (OA). [ABSTRACT FROM AUTHOR]

BACKGROUND: Dynamic knee valgus (DKV) is a known risk factor for acute and chronic knee injuries and is more frequently diagnosed in females. A real-time single-leg squat test (SLST) could screen for DKV to prevent injuries. OBJECTIVE: To compare the differences in lower extremity strength and range of motion (ROM) in female soccer athletes with and without DKV during an SLST. METHODS: Eighteen subjects with DKV (DKV group) and 18 subjects without DKV (control group) during a single-leg squat were included. Hip strength (flexion, extension, abduction, adduction, internal rotation, and external rotation) was measured with a hand-held dynamometer. Hip ROM (internal and external rotation), and ankle ROM (dorsiflexion with the knee flexed and extended) were measured. Independent t-test was used to compare the averages of the groups. RESULTS: There were significant differences in hip abduction to adduction strength ratio (DKV: 1.48 ± 0.3, control: 1.22 ± 0.26, p < 0.01) and ankle dorsiflexion with knee flexed (DKV: 17.22 ± 6.82, control: 21.22 ± 4.55, p < 0.05) and extended (DKV: 10.14 ± 4.23, control: 14.75 ± 3.40, p < 0.001) between the groups. CONCLUSION: The hip abduction to adduction strength ratio and gastrocnemius and soleus flexibility may be associated factors in dynamic knee valgus and therefore should be assessed and treated, if indicated, as a possible preventive measure in female athletes with this variation. [ABSTRACT FROM AUTHOR]

Background: Adipokines gene polymorphisms are speculated to be associated with the risk of knee osteoarthritis (OA), but evidence remains conflicting. This study therefore aimed to examine whether associations exist between adipokines gene polymorphisms and knee OA by considering the evidence collected from eligible studies through a meta-analysis.Methods: A systematic search was performed on PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), and Wanfang up to March 31, 2020. Meta-analysis was carried out by focusing on the associations between adipokines gene polymorphisms and knee OA with the allele model, dominant model, and recessive model.Results: The present meta-analysis included 5 eligible studies for ADIPOQ rs1501299 with 1,021 cases and 1,097 controls, 3 eligible studies for ADIPOQ rs2241766 with 549 cases and 544 controls, 3 eligible studies for LEPR rs1137101 with 808 cases and 856 controls, 2 eligible studies for VISFATIN rs4730153 with 339 cases and 680 controls and 2 eligible studies for VISFATIN rs16872158 with 339 cases and 680 controls. Significant association was observed between LEPR rs1137101 and knee OA in the overall population (recessive: OR = 0.40, 95% CI 0.21-0.79). Limited data revealed that associations may exist between ADIPOQ rs2241766 and knee OA in Asians (dominant: OR = 1.35, 95% CI 1.03-1.78), between VISFATIN rs4730153 and knee OA in Asians (allele: OR = 0.58, 95% CI 0.41-0.83; dominant: OR = 0.57, 95% CI 0.39-0.83), and between VISFATIN rs16872158 and knee OA in Asians (allele: OR = 1.84, 95% CI 1.26-2.68; dominant: OR = 1.94, 95% CI 1.31-2.89).Conclusions: Adipokines gene polymorphisms may be associated with knee OA. The association was observed in LEPR rs1137101 in the present study. In addition, limited data revealed that associations may also exist in ADIPOQ rs2241766, VISFATIN rs4730153 and VISFATIN rs16872158.Prospero Registration: CRD42020187664. [ABSTRACT FROM AUTHOR]

The aim of this study was to propose a tread swing mechanism for lower-limb strength training devices and to confirm its effects. In the standing position and for training the lower limbs, if the tread-surface angle is inappropriate, the posture of the knee joints gets affected, and knee adduction/valgus moments, which result in knee stress, get generated. The target training exercises are the front-back leg scissors and open-close leg triangle exercises. With regard to the swing of the tread, it is necessary to realize a pitch/yaw rotation and a roll/yaw rotation for the former and the latter exercises, respectively. As a result, knee joint stress can be reduced by moving the center of pressure (COP). The proposed mechanism has a further differential mechanism that utilizes the difference between the pulley diameters. The translational movement force of the tread is transmitted as the torque of the swing motion for the pitch, roll, and yaw through the effects of a differential mechanism. The rate of the swing angle can be changed by adjusting the pulley diameter. As a result of evaluating the effect of exercises using a manufactured device, it was confirmed that the tread performed a predetermined swing motion. It was also confirmed that the COP position changed. Therefore, it is expected that knee joint stress will reduce. Rehabilitation and strength training that result in small knee joint stresses and generate large muscle load are in great demand for people experiencing knee joint failure. [ABSTRACT FROM AUTHOR]

Background: Gait speed is recognized to correlate to knee kinematic alterations. Clinically, patients with knee diseases tend to walk slowly compared to healthy controls. Hence, gait speed may serve as a confounding factor in the kinematic characteristics of patients during gait compared to healthy controls.Research Question: Whether and how gait speed affects six degrees of freedom (6DOF) knee kinematics remains unclear. The current study was designed to explore whether and how decreased gait speeds affect 6DOF knee kinematics.Methods: Thirty subjects (15 males and 15 females) were recruited for this study. A three-dimensional gait analysis system was used to assess the 6DOF knee kinematics of subjects at gait speeds of 4.0 km/h, 3.5 km/h, 3.0 km/h, 2.5 km/h, 2.0 km/h, 1.5 km/h, and 1.0 km/h. Kinematics of gait cycle (GC) were assessed at all gait speed levels.Results: Decreased adduction angle (0.5-3.2 °, p < 0.05), increased external rotation (0.6-3.3 °, p < 0.05) and decreased flexion angle (1.5-17.4 °, p < 0.05) were found during most GC as gait speed level decreased. Greater anterior tibial translation (0.9-2.6 mm, p < 0.05), greater proximal translation (0.4-2.4 mm, p < 0.05) and decreased lateral tibial translation (0.5-3.0 mm, p < 0.05) were found during most GC as gait speed level decreased. Gender was also found to have great effects on 6DOF knee kinematics (p < 0.05). Interactions between gender and gait speed were also found (p < 0.05).Significance: Our findings suggest that additional attention should be paid when dealing with kinematic comparisons of GC between controls and patients with significantly different gait speeds or genders than controls. Kinematic alterations induced by gait speed may raise concern for patients with knee diseases who struggle to walk faster than their normal speed. This may enhance our knowledge of the relationship between gait speed and 6DOF knee kinematics. [ABSTRACT FROM AUTHOR]

Objective: To describe the variability in: (1) the contributions of 3D hip and knee kinematics to the dynamic knee valgus (DKV) movement pattern during a single limb squat in women with patellofemoral pain; and (2) the 3D strategies used to reduce DKV following an intervention. Methods: Secondary analysis of a feasibility study investigating a movement training intervention. In 23 participants, 2D knee frontal plane projection angles (FPPA) and 3D hip and knee frontal and transverse plane angles at peak knee flexion were calculated during a single limb squat at pre- and post-intervention, and the change in 2D and 3D angles computed. 3D angles at pre-intervention were summed for each participant to create cumulative bar graphs. Similar graphs were created for change in 3D angles. For visual comparison, graphs were ordered by increasing knee FPPA or change in knee FPPA. Results: The knee FPPA decreased from a mean of 7.2 degrees (SD: 7.1) to a mean of −8.9 degrees (SD: 8.9) following the intervention. A large portion of DKV, and change in DKV, was due to hip adduction and knee lateral rotation, yet participants with similar knee FPPA and change in knee FPPA displayed variation in all 3D components and change in 3D components. Conclusion: People who demonstrate similar observed movement patterns during a weight-bearing task may use different 3D strategies for execution. [ABSTRACT FROM AUTHOR]

Knee pain is the most common and debilitating symptom of knee osteoarthritis (OA). While there is a perceived association between OA imaging biomarkers and pain, there are weak or conflicting findings for this relationship. This study uses Deep Learning (DL) models to elucidate associations between bone shape, cartilage thickness and T2 relaxation times extracted from Magnetic Resonance Images (MRI) and chronic knee pain. Class Activation Maps (Grad-CAM) applied on the trained chronic pain DL models are used to evaluate the locations of features associated with presence and absence of pain. For the cartilage thickness biomarker, the presence of features sensitive for pain presence were generally located in the medial side, while the features specific for pain absence were generally located in the anterior lateral side. This suggests that the association of cartilage thickness and pain varies, requiring a more personalized averaging strategy. We propose a novel DL-guided definition for cartilage thickness spatial averaging based on Grad-CAM weights. We showed a significant improvement modeling chronic knee pain with the inclusion of the novel biomarker definition: likelihood ratio test p-values of 7.01 × 10–33 and 1.93 × 10–14 for DL-guided cartilage thickness averaging for the femur and tibia, respectively, compared to the cartilage thickness compartment averaging. [ABSTRACT FROM AUTHOR]

BACKGROUND: Total knee arthroplasty is an effective method for the treatment of end-stage knee osteoarthritis. The key to total knee arthroplasty is to restore the accurate lower limb alignment and good flexion and extension space balance. Gap balance technique and measurement osteotomy technique are two classical osteotomy methods, which methods to choose is still controversial. OBJECTIVE: To compare radiographical manifestations of gap balance technique and measurement osteotomy technique in total knee arthroplasty patients, and analyze application effect of gap balance technique in total knee arthroplasty patients. METHODS: Clinical data of 118 patients with total knee arthroplasty were retrospectively analyzed, including 42 males and 76 females, aged 53-72 years old. According to intraoperative osteotomy methods, they were divided into gap balance group (61 cases) and measurement osteotomy group (57 cases). In 12-month follow-up, X-ray films were taken to measure the coronal hip-knee-ankle angle, lower line force angle and femoral flexion angle. Visual analogue scale score and American knee society knee score were used to evaluate the pain degree and knee function. This study was approved by the Ethics Committee of Guiyang Fourth People’s Hospital. RESULTS AND CONCLUSION: (1) The gap balance group had local infection in three cases. The measurement osteotomy group had local infection in four cases, rejection in one case, and immune reaction in one case. There was no significant difference in complications between the two groups (4.92%, 10.53%, P > 0.05). (2) In 12-month follow-up, knee flexion 90° stress angle of medial and lateral tibiofemoral joint was lower in the gap balance group than that in the measurement osteotomy group (P < 0.001). Coronal hip-knee-ankle angle and lower limb alignment were smaller in the gap balance group than those in the measurement osteotomy group (P < 0.001). Maximum femoral flexion angle was larger in the gap balance group than that in the measurement osteotomy group (P < 0.001). (3) In 12-month follow-up, visual analogue scale scores were lower in the gap balance group than those in the measurement osteotomy group (P < 0.001). American knee society knee score was higher in the gap balance group than that in the measurement osteotomy group (P < 0.01). (4) Results showed that gap balance technology help to maintain a good lower limb alignment and flexion extension gap space, relieve the pain and improve the knee function during total knee arthroplasty. [ABSTRACT FROM AUTHOR]

Background: Lateral wedge insoles (LWI), standalone or with medial arch support (supported-LWI), have been thoroughly investigated for their effects on modifying gait biomechanics for people with knee osteoarthritis. However, plantar pressure distribution between these insole types has not been investigated and could provide insight towards insole prescription with concomitant foot symptoms taken into consideration. Methods: In a sample of healthy individuals (n = 40), in-shoe plantar pressure was measured during walking with LWI, with or without medial arch support (variable- and uniform-stiffness designs), and a flat control insole condition. Pressure data from the plantar surface of the foot were divided into seven regions: medial/lateral rearfoot, midfoot, medial/central/lateral forefoot, hallux. Plantar pressure outcomes assessed were the medial-lateral pressure index (MLPI) for the whole foot, and the peak pressure, pressure-time integral (PTI), and contact area in each plantar region. Comfort in each insole condition was rated as a change relative to the flat control insole condition. Repeated-measures analyses of variance were calculated to compare the plantar pressure outcomes between insole conditions. Results: Regionally, medial rearfoot and forefoot pressure were reduced by all wedged insoles, with the variable-stiffness supported-wedge showing greater reductions than the standalone wedge. Lateral rearfoot and forefoot pressure were reduced by both supported-LWI, but unchanged by the standalone wedge. In the midfoot, the standalone wedge maintained pressure but reduced regional contact area, while both supported-LWI increased midfoot pressure and contact area. All LWI increased the MLPI, indicating a lateral shift in plantar pressure distribution throughout the weightbearing phase of gait. Comfort ratings were not significantly different between insole conditions. Conclusions: Regional differences in plantar pressure may help determine an appropriate lateral wedge insole variation to avoid exacerbation of concomitant foot symptoms by minimizing pressure in symptomatic regions. Lateral shifts in plantar pressure distribution were observed in all laterally wedged conditions, including one supported-LWI that was previously shown to be biomechanically ineffective for modifying knee joint load distribution. Thus, shifts in foot centre of pressure may not be a primary mechanism by which LWI can modify knee joint load distribution for people with knee osteoarthritis. [ABSTRACT FROM AUTHOR]

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