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Patients with hallux valgus are known to alter lower limb joint kinematics during gait. However, little information is available about gait changes following hallux valgus surgery. We aimed to longitudinally investigate lower limb kinematic changes at the mid and terminal stances of gait after hallux valgus surgery. This prospective observational study included 11 female patients (17 feet), who underwent first metatarsal osteotomy. Gait analyses were performed preoperatively and 1- and 2-year postoperatively using a three-dimensional motion capture system. Toe-out angle, ankle, knee, and hip joint angles during gait were calculated from the recorded data. The spatiotemporal parameters and these angles at the mid and terminal stances of gait were statistically compared between preoperative and postoperative periods. All spatiotemporal parameters remained unchanged postoperatively. The toe-out angle was significantly greater at 1- and 2-year postoperatively. The ankle pronation angle, the knee abduction angle, and the hip adduction angle at the mid and terminal stances of gait were smaller postoperatively compared to the preoperative. These angular changes showed a similar trend at 1 and 2 years postoperatively. However, the postoperative changes of the sagittal joint angles were relatively small. Hallux valgus surgery can affect the toe-out angle and the lower limb coronal kinematics at the mid and terminal stances of gait in patients with hallux valgus. However, surgical correction of hallux valgus deformity did not directly improve the gait characteristics in patients with hallux valgus. • Kinematic effects of ankle, knee, and hip joints during gait in bunion surgery. • Preoperative and 1- and 2-year postoperative gait analyses by a motion capture system. • Bunion surgery changes toe-out angle and lower limb coronal kinematics during gait. [ABSTRACT FROM AUTHOR]

Early diagnosis and treatment of osteoarthritis of the thumb allows for early interventions that may mitigate osteoarthritis progression and decrease severity later in life. Early identification of motion changes is limited by the clinical reliance on single planar measurements using goniometry. Multi-planar measurements using motion capture can provide insights into joint function and pathophysiology that cannot be obtained from single-plane goniometry measurements. Thus, the goals of this research were 1) to determine differences in thumb motions across three groups of participants (young healthy (n = 23), older healthy (n = 11), and those with carpometacarpal osteoarthritis (n = 24)) and 2) to determine if multi-planar motions provided additional movement information in comparison to standard planar measures. In this study, a motion capture system was used to collect standard clinical ranges of motion and complex multi-planar tasks. Differences in motion patterns due to aging and osteoarthritis were identified. Motions tested included palmar adduction-abduction, radial adduction-abduction, metacarpophalangeal flexion-extension, interphalangeal flexion-extension, functional adduction-abduction, opposition, and circumduction. Results indicated that motion capture was capable of detecting changes in carpometacarpal mobility that were not detected using standard approaches. Our results suggested that use of multi-planar measurements have the potential to identify changes that are indicators of early stages of osteoarthritis. Early indicators are clinically useful as they will enhance patient treatment by permitting the application of treatment approaches sooner, potentially leading to reduced overall functional deficits. • Multi-planar motions have the potential to be early indicators of osteoarthritis • Motion capture detects motion changes that cannot be detected using goniometry • Distal thumb joint motion changes may manifest prior to significant carpometacarpal motion loss [ABSTRACT FROM AUTHOR]

While body-powered prostheses are commonly used, the compensatory strategies required to operate body-powered devices are not well understood. Kinematic assessment in addition to standard clinical tests can give a comprehensive evaluation of prosthesis user function and skill. This study investigated the movement compensations of body-powered prosthesis users and determined whether a correlation is present between compensatory strategies and skill level, as measured by a standard clinical test. Five transradial body-powered prosthesis users completed two standardized upper limb tasks. A 12-camera motion capture system was used to obtain three-dimensional angular kinematics for eight degrees of freedom at the trunk, shoulder, and elbow. Range of motion was compared to a normative dataset. Pearson's correlation was used to assess the relationship between the Activities Measure for Upper Limb Amputees and range of motion for each degree of freedom. Participants displayed a statistically significant (P <.05) increase in range of motion at the trunk for both tasks. Shoulder flexion/extension range of motion was significantly reduced (P <.05) compared to normative values, but shoulder abduction/adduction range of motion did not show a consistent difference compared to norms. Skill level was correlated with range of motion for specific degrees of freedom at the trunk, shoulder, and elbow. Body-powered prosthesis users compensated with trunk movement and showed reduced motion for shoulder flexion/extension, with relatively normal shoulder abduction/adduction. Skill level was correlated with angular kinematic strategies, which may allow targeting of specific therapeutic interventions for reducing compensatory movements. • Compensatory strategies of body-powered prostheses users are not well documented. • Users of transradial body-powered prostheses compensate mainly with the trunk. • Shoulder and elbow flexion/extension is significantly reduced compared to norms. • Higher skill level linked to reduced trunk flexion and increased axial rotation • Higher skill level also linked to more normal shoulder and elbow flexion ranges [ABSTRACT FROM AUTHOR]

Osteoarthritis after anterior cruciate ligament reconstruction has been linked with changes in gait. Individuals with reconstruction demonstrate gait changes after exercise, however there is no information on altered gait after exercise based on sex. The purpose of this study was to examine the association of sex on changes in running gait after exercise in individuals with reconstruction compared to healthy. Forty females (22 reconstructed) and 22 men (11 reconstructed) ran before and after exercise. Triplanar lower extremity kinematics and kinetics were measured on the involved limb. Data were reduced to 0–100% of gait. Change scores were calculated for each 1% with 90% confidence intervals. Mean differences were calculated for all significant differences. After exercise, females with reconstruction increased knee valgus (1.81°), knee external rotation (2.02°), lateral trunk flexion (1.24°) and trunk rotation (2.15°) compared to healthy females. Females with reconstruction increased knee extension moment (0.07 Nm/kg), knee abduction moment (0.08 Nm/kg), hip extension moment (0.14 Nm/kg) and hip internal rotation moment (0.04 Nm/kg) compared to healthy females. After exercise, males with reconstruction decreased knee varus (−4.83°), hip adduction (−1.99°), and hip internal rotation (−4.44°), however increased lateral trunk flexion (1.94°) compared to healthy males. Males with reconstruction increased knee extension moment (0.07 Nm/kg), knee adduction moment (0.31 Nm/kg), knee internal rotation moment (0.13 Nm/kg), hip flexion moment (0.17 Nm/kg), and hip external rotation moment (0.05 Nm/kg) compared to healthy males. Males with reconstruction increased hip loading while women with reconstruction increased trunk motion post-exercise. Sex should be considered when evaluating response to exercise after reconstruction. • We compared gait after exercise after knee ligament reconstruction between sexes. • Changes in sagittal kinematics after exercise are similar to healthy controls. • Women with reconstruction increased frontal and transverse motion post-exercise. • Men maintained pre-exercise frontal and transverse plane loading post-exercise. [ABSTRACT FROM AUTHOR]

Repeated exposures to larger lateral trunk-pelvic motion and features of knee joint loading likely influence the onset of low back pain and knee osteoarthritis among persons with lower-limb amputation. Decreased hip abductor strength can also influence frontal plane trunk-pelvic motion and knee moments; however, it is unclear how these are inter-related post-amputation. Twenty-four participants with unilateral lower-limb amputation (14 transtibial; 10 transfemoral) and eight uninjured controls walked at 1.3 m/s while full-body biomechanical data were captured. Multiple linear regression and Cohen's f 2 predicted (P < 0.05) the influences of mediolateral trunk and pelvic ranges of motion and angular accelerations, and bilateral isometric hip abductor strength on peak (intact) knee adduction moment and loading rate. There were no group differences in hip strength, peak knee adduction moment or pelvis acceleration (p > 0.06). The combination of hip strength, and mediolateral trunk and pelvic motion did not predict (F (5,29) = 2.53, p = 0.06, adjusted R2 = 0.27, f 2 = 0.08) peak knee adduction moment. However, the combination of hip strength and trunk and pelvis acceleration predicted knee adduction moment loading rate (F (7,29) = 3.59, p = 0.008, adjusted R2 = 0.45, f 2 = 0.25), with peak trunk acceleration (β = 0.72, p = 0.008) and intact hip strength (β = 0.78, p = 0.008) significantly contributing to the model. These data suggest increased hip abductor strength counteracts increased lateral trunk acceleration, concomitantly influencing the rate at which the ground reaction force vector loads the intact knee joint. Persons with lower-limb amputation perhaps compensate for increased intact limb loading by increasing trunk motion, thereby increasing demand on hip abductors to attenuate this preferential loading. • Hip abductor strength influenced moment loading rate in intact knees rather than peak moment. • Frontal plane trunk motion is associated with knee adduction moment loading rate. • No differences by presence or level of limb loss (transtibial vs. transfemoral) • There is interplay between proximal and distal outcomes after limb loss. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a clinical problem affecting an estimated 27 million adults in the United States, with the only clear treatment options being pain management. Cycling is an integral component of exercise for individuals with knee osteoarthritis, while the joint reaction forces during cycling remain unknown. Thirteen subjects with medial compartment knee osteoarthritis and eleven healthy subjects performed a cycling protocol with a neutral pedal and four pedal modifications. Six hundred muscle-actuated inverse-dynamic simulations (24 subjects, 5 trials in each of 5 conditions) were performed to estimate joint reaction force differences between conditions. Subjects with knee osteoarthritis had many significant changes among them was a reduction in knee adduction-abduction moment by 45% (5° lateral wedge), 77% (10° lateral wedge), 54% (5° toe-in) and 58% (10° toe-in). Conversely the healthy subjects had no significant changes in the knee adduction-abduction moment for the lateral wedge conditions and the 5° toe-in but did decrease by 18% for the 10° toe-in condition. When comparing the cohorts across the different pedal conditions, the data showed many significant differences among the groups. This study showed that while cycling in different pedal modifications, the knee osteoarthritis subjects had more beneficial changes in their knee adduction-abduction moment compared to the healthy subjects with the lateral-wedge modification resulting in the greatest impact on the subjects with knee osteoarthritis. Both groups had greater contact forces at the hip and ankle across pedal modifications compared to neutral. For the knee, subjects with osteoarthritis mostly decreased their knee contact forces but the healthy subjects mostly increased these forces with all pedal modifications. • The knee osteoarthritis cohort saw increases in the hip and ankle contact forces. • The healthy subjects saw no significant decrease in the adduction-abduction moment. • The healthy cohort was affected more negatively than the osteoarthritis cohort. • The healthy subjects saw more increases in the contact forces across all joints. • The osteoarthritis subjects saw decreases in joint contact loads at the knee. [ABSTRACT FROM AUTHOR]

Excess body mass is thought to be a major cause of altered biomechanics in obesity, but the effects of body mass distribution in biomechanics during daily living tasks are unknown. The purpose of this study was to determine how increasing body mass centrally and peripherally affects lower extremity kinematics, kinetics, and muscle activation when transitioning from stair descent to level gait. Fifteen normal weight volunteers descended a staircase at a self-selected pace under unloaded, centrally loaded, and peripherally loaded conditions. Spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and mean electromyography amplitude were calculated using 3D motion analysis. Both central and peripheral loading reduced gait velocity. Peripheral loading increased time spent in stance phase, increased step width, and reduced step length. At the hip joint, peripheral loading reduced peak hip extension and adduction angle. Conversely, central loading reduced peak hip flexor moment. Both central and peripheral loading increased peak knee flexion angle, but only peripheral loading increased peak knee extensor moment. Central and peripheral loading increased mean electromyography amplitude of the medial gastrocnemius, but only peripheral loading increased mean electromyography amplitude of the semitendinosus and the vastus medialis. Increasing mass centrally and peripherally differently affects spatial-temporal gait characteristics and lower extremity joint kinematics, kinetics, and electromyography when transitioning from stair descent to level gait. Body mass distribution may be an important factor for obesity-induced biomechanical alterations and should be considered when developing biomechanical models of obesity. • Increasing body mass, regardless of distribution, reduces stair descent velocity • Adding mass to thighs, but not the trunk, negatively impacts spatial-temporal parameters during stair transition • Hip and knee kinematics and kinetics are differently affected by adding mass to the trunk and thighs • Adding mass to the thighs, but not the trunk, increases EMG activity of the knee flexors and extensors • Distribution of mass is an important determinant of kinematics, kinetics, and muscle recruitment during stair transitions [ABSTRACT FROM AUTHOR]

The purpose of this study was to measure the three-dimensional range of motion of adjacent, unfused joint or joints after different arthrodesis of hindfoot. Sixteen fresh frozen cadaver feet were immobilized in the non-weight bearing position. The three-dimensional coordinates of markers in tarsal were measured in six directions (involving dorsiflexion-plantarflexion, eversion-inversion, and adduction-abduction) before and after single (involving subtalar joint, talonavicular joint, and calcaneocuboid joint) and double (talonavicular and calcaneocuboid joints) arthrodesis with a three-dimensional coordinate instrument. The range of motion of the joint was calculated with the least square method and matrix transformation. We found that the range of motion of joints in all direction was reduced significantly after any combination of selective arthrodesis (all p < 0.001). After arthrodesis of the subtalar joint, the motion of talonavicular joint was reduced by 72%, and that of calcaneocuboid joint by 36%. After arthrodesis of talonavicular joint, the motion of subtalar joint was diminished by 36%, and that of calcaneocuboid joint by 51%. After arthrodesis of calcaneocuboid joint, the motion of subtalar joint was decreased by 21%, and that of talonavicular joint by 42%. After double arthrodesis, the motion of subtalar joint was reduced by 62%. In single arthrodesis, subtalar arthrodesis had the greatest effect on the motion of unfused joints, and the least was the calcaneocuboid arthrodesis. The motion of the subtalar joint was eliminated more than half after double arthrodesis. The data provide a biomechanical rationale to ascertain the clinical implication of the arthrodesis. • Before arthrodesis, the motion from larger to small is talonavicular, calcaneocuboid, and subtalar joint. • In single arthrodesis, subtalar arthrodesis has the greatest effects on the motion of other joints. • In single arthrodesis, calcaneocuboid arthrodesis has the least effects on the motion of other joints. • The motion of the subtalar joint was eliminated more than half after double arthrodesis. [ABSTRACT FROM AUTHOR]

An increased external knee adduction moment has been identified as a factor contributing to the progression of medial knee osteoarthritis. Interventions that reduce knee adduction moment may help prevent knee osteoarthritis onset and progression. While exercise interventions have been commonly used to treat knee osteoarthritis, whether exercises can modulate knee adduction moment in knee osteoarthritis patients remains unknown. This systematic review and meta-analysis aimed to determine if exercise interventions are effective in reducing knee adduction moment during gait. Study reports published through May 2023 were screened for pre-specified inclusion/exclusion criteria. Nine studies met the eligibility criteria and yielded 24 effect sizes comparing the reduction in knee adduction moment of the exercise intervention groups to the control groups. Moderator/experimental variables concerning characteristics of the exercise interventions and included subjects (e.g., sex, BMI, type of exercise, muscle group targeted, training volume, physical therapist supervision) that may contribute to variation among studies were explored through subgroup analysis and meta-regression. The effect of exercise intervention on modulating knee adduction moment during gait was no better than control (ES = -0.004, P = 0.946). Sub-group analysis revealed that the effect sizes of studies containing only females (positive exercise effect) were significantly greater than studies containing both males and females. Exercise may not be effective in reducing knee adduction moment during gait. Clinicians aiming to decrease knee adduction moment in patients with medial knee osteoarthritis should consider alternative treatment options. Exploring the underlying mechanism(s) regarding a more positive response to exercises in females may help design more effective exercise interventions. • Exercises may not reduce knee adduction moment in knee osteoarthritis patients. • Type, muscles targeted, or volume does not alter exercise effects on knee loading. • Women may benefit more from exercises in reducing knee adduction moment than men. • Exercise benefits for osteoarthritis patients are not from knee loading modulation. [ABSTRACT FROM AUTHOR]

The effect of pain on lower limb biomechanics during walking has been found to be sex specific for certain joint diseases. However, it is not known if sex is an effect-modifier in people with hip pain. Therefore, the aim of the study was to determine the differences in lower limb biomechanics between men and women with hip-related groin pain during functional tasks. 65 male and 23 female football players with hip-related groin pain were recruited. Biomechanical data were recorded during walking and the single-leg drop jump. Hip, knee and ankle joint kinematics and kinetics were calculated. Differences between men and women were assessed using statistical parametric mapping. Walking: Men with hip-related groin pain walked with lower hip flexion and internal rotation angles during stance compared to women. During different sections of stance, men also displayed a lower hip adduction angle and 'external' adduction moment, a lower knee flexion angle and 'external' flexion moment, as well as greater 'external' dorsi-flexion moment and impulse. Single-leg drop jump: Men with hip-related groin pain displayed a lower hip flexion angle during early stance, and greater 'external' knee flexion and ankle dorsi-flexion moments. The impulse of the 'external' dorsi-flexion moment was also greater for men compared to women. Men and women with hip-related groin pain display differing lower limb biomechanics in both low and high impact tasks. Sex may therefore be a potential effect modifier in people with hip-related groin pain. Future research in this area should incorporate sex-specific analyses. NA. • Men and women with hip-related groin pain have differing lower limb biomechanics. • Ankle joint biomechanics were consistently different between groups across tasks. • Sex may be an effect modifier in hip-related groin pain biomechanics. [ABSTRACT FROM AUTHOR]

Abstract Background Contra-lateral knee joint function in individuals with moderate knee osteoarthritis is not well understood, despite the functional burden of bilateral osteoarthritis on end stage clinical management. The purpose of this study was to determine whether co-activation and joint biomechanics are altered in the contra-lateral limb compared to age-matched controls. Methods 20 Individuals with moderate knee osteoarthritis and 20 asymptomatic individuals walked on an instrumented dual belt treadmill at a self-selected speed. Surface electromyography of the knee joint musculature, including quadriceps, hamstrings and gastrocnemius muscles, normalized to maximum voluntary isometric contractions, as well as sagittal plane motion and sagittal and frontal plane moments were collected. Co-contraction indices were calculated and discrete variables from motion and moment data were extracted. Two-sample t -tests and 2-sample mixed model ANOVAs were performed with alpha <0.05. Findings Contra-lateral knee muscle co-activation differences were not found between groups (p > 0.65). Peak knee adduction moment (0.41 Nm/kg vs. 0.32 Nm/kg) and knee adduction moment impulse (0.14 Nm s/kg vs. 0.10 Nm s/kg) were higher in the contra-lateral limb compared to the asymptomatic group respectively, whereas the sagittal motion (9.8° vs. 14.4°) and moment ranges (0.66 Nm/kg vs. 0.86 Nm/kg) during stance were less dynamic (p < 0.03). Interpretation The contra-lateral limb was functioning differently biomechanically despite no changes present in muscle co-activation. Findings suggest biomechanical changes are occurring without greater demand on the neuromuscular system to preserve contra-lateral joint function in moderate knee osteoarthritis gait. A greater focus should be made to address biomechanical abnormalities in both knees of individuals with moderate unilateral symptomatic knee osteoarthritis. Highlights • Contra-lateral co-contraction not different from asymptomatic controls • Greater contra-lateral knee adduction moment compared to control • Sagittal plane moments and angles less dynamic in contra-lateral knee • Contra-lateral knee function abnormal, but not enough to alter co-contraction [ABSTRACT FROM AUTHOR]

Background Abnormal knee mechanics may contribute to early cartilage degeneration following anterior cruciate ligament reconstruction. Anterior cruciate ligament graft geometry has previously been linked to abnormal tibiofemoral kinematics, suggesting this parameter may be important in restoring normative cartilage loading. However, the relationship between graft geometry and cartilage contact is unknown. Methods Static MR images were collected and segmented for eighteen subjects to obtain bone, cartilage, and anterior cruciate ligament geometries for their reconstructed and contralateral knees. The footprint locations and orientation of the anterior cruciate ligament were calculated. Volumetric, dynamic MR imaging was also performed to measure tibiofemoral kinematics, cartilage contact location, and contact sliding velocity while subjects performed loaded knee flexion-extension. Multiple linear regression was used to determine the relationship between non-anatomic graft geometry and asymmetric knee mechanics. Findings Non-anatomic graft geometry was related to asymmetric knee mechanics, with the sagittal plane graft angle being the best predictor of asymmetry. A more vertical sagittal graft angle was associated with greater anterior tibial translation ( β  = 0.11 mm deg , P  = 0.049, R 2  = 0.22), internal tibial rotation ( β  = 0.27 deg deg , P  = 0.042, R 2  = 0.23), and adduction angle ( β  = 0.15 deg deg , P  = 0.013, R 2  = 0.44) at peak knee flexion. A non-anatomic sagittal graft orientation was also linked to asymmetries in tibial contact location and sliding velocity on the medial ( β  = −4.2 mm s deg , P  = 0.002, R 2  = 0.58) and lateral tibial plateaus ( β  = 5.7 mm s deg , P  = 0.006, R 2  = 0.54). Interpretation This study provides evidence that non-anatomic graft geometry is linked to asymmetric knee mechanics, suggesting that restoring native anterior cruciate ligament geometry may be important to mitigate the risk of early cartilage degeneration in these patients. [ABSTRACT FROM AUTHOR]

Background To determine the influence of femur and tibia rotations in the transverse and frontal planes on patella cartilage stress. Methods Patella cartilage stress profiles of six healthy females were obtained during a squatting task using subject-specific finite element models of the patellofemoral joint (45° of knee flexion). Input parameters for the finite element model included joint geometry, quadriceps muscle forces, and weight-bearing patellofemoral joint kinematics. The femur and tibia of each model were then rotated to 2°, 4°, 6°, 8°, and 10° along their respective axes beyond that of the natural degree of rotation in weight-bearing. The process was repeated for internal rotation, external rotation, adduction, and abduction. Quasi-static loading simulations were performed to quantify average patella cartilage stress. Findings Incremental femur internal rotation beyond that of the natural rotation resulted in progressively greater patella cartilage stress (41–77%), whereas incremental tibia internal rotation resulted in a decrease in patella cartilage stress (7–10%). Femur and tibia external rotation resulted in a mild increase in patella cartilage stress, but only at 10° (9%). Incremental femur adduction resulted in an increase in patella cartilage stress, but only at 10° (43%). Femur abduction and frontal plane tibia rotation in either direction had no influence on patella cartilage stress. Interpretation Femur internal rotation and adduction resulted in the greatest increases in patella cartilage stress. In contrast, tibia rotations in the transverse and frontal planes had minimal to no influence on patella cartilage stress. These results emphasize the need for clinicians to identify and correct faulty hip kinematics in persons with PFP. [ABSTRACT FROM AUTHOR]

Background Investigate differences in multi-segment foot kinematics between controls and participants with chronic ankle instability during running with a midfoot striking pattern and to evaluate the effect of Low-Dye and High-Dye taping. Methods Three-dimensional multi-segment foot kinematics of 12 controls and 15 participants with chronic ankle instability were collected while running barefoot, and in both taping conditions. Ranges of motion occurring at each joint, each sub phase of stance, were compared between groups and between taping conditions (0-dimensional inference). Kinematic data were also compared using one-dimensional statistical parametric mapping. Findings The symptomatic group demonstrated while barefoot running a significantly decreased rearfoot dorsiflexion range of motion during the peak impact phase as well as a less dorsiflexed position from 6 to 12% of the running cycle. During the absorption and generation phase, the symptomatic group also showed a significantly increased rearfoot dorsiflexion and adduction motion as well as an increased midfoot inversion motion. In the peak impact phase of both taping conditions, a decreased midfoot inversion motion was found. The High-Dye taping resulted in a decreased rearfoot plantarflexion motion whereas the Low-Dye caused a decreased midfoot inversion motion. Interpretation Persons with chronic ankle instability seem to have altered rearfoot and midfoot kinematics while running with a midfoot striking index. High-Dye taping seems to have better therapeutic features than Low-Dye taping. [ABSTRACT FROM AUTHOR]

Background Recent studies highlight the need for understanding movement control of adjacent joints when evaluating knee function following anterior cruciate ligament (ACL) injury. However, while short-term adaptations to lower-extremity joint coupling have been studied, little is known about any potential long-term adaptations in neuromuscular control displayed by ACL-injured individuals. The aim of our study was to determine whether coordination variability of the hip-knee joint couplings during the one-leg hop is altered about 20 years after injury in two ACL-injured groups compared to healthy knee controls. Methods Seventy persons performed one leg hops ~23 years after ACL injury and following different treatments: 33 participants treated with physiotherapy in combination with ACL-reconstruction (ACL R ); 37 participants with physiotherapy alone (ACL PT ). They were compared to 33 matched controls. A vector coding procedure was used to create joint couplings for knee and hip angles on all the cardinal planes for the Take-off and Landing phases. The standard deviation of each coupling was computed as a measure of coordination variability. Findings Both the ACL groups differed significantly from controls on their injured side with ~50% higher knee abduction-adduction/hip internal-external rotation variability during the Take-off phase; ~33% higher knee abduction-adduction/knee flexion-extension variability and greater knee abduction-adduction/hip flexion-extension variability (ACL R 50%; ACL PT 80%) during the Landing phase. There were no major differences between injured and non-injured sides in any group. Interpretation Increased variability in lower-extremity joint couplings has emerged as a conspicuous feature of ACL injured persons in the very long term compared to non-injured controls, independent of treatment. Further research of the processes leading to alterations in movement variability using longitudinal studies would facilitate better understanding of the functional adaptations leading to knee dysfunction in the short- and long-term after ACL injury. [ABSTRACT FROM AUTHOR]

Background Despite the large number of cross-sectional studies on gait in subjects with knee osteoarthritis, there are scarcely any longitudinal studies on gait changes in knee osteoarthritis. Methods Gait analysis was performed on 25 women with early and 18 with established medial knee osteoarthritis, as well as a group of 23 healthy controls. Subjects were asked to walk at their comfortable speed. Kinematic and kinetic data were measured at baseline and after 2 years follow-up. Findings Results indicated that the early osteoarthritis group, similar to established osteoarthritis group, showed significantly higher maximum knee adduction angles compared to the controls during the early stance phase of gait. None of the kinematic or kinetic measures, changed over two years in the early osteoarthritis group. In the established osteoarthritis group, at the time of entry, an increased first and second peak knee adduction moment, as well as higher mid-stance knee adduction moment and knee adduction moment impulse, were present compared to the control and the early osteoarthritis groups. Mid-stance knee adduction moment and knee adduction moment impulse, further increased over two years only in the established osteoarthritis group. For all three groups, the peak knee flexion angle during the stance phase decreased significantly over time. Interpretation Increased maximum knee adduction angle during stance phase was the only alteration in the gait pattern of subjects with early knee osteoarthritis compared to the controls. This suggests that, unlike in the later stages of the disease, gait is rather stable over two years in early osteoarthritis. [ABSTRACT FROM AUTHOR]

Background The contact biomechanics of the trapeziometacarpal joint have been investigated in several studies. However, these led to conflicting results and were mostly performed in vitro. The purpose of this study was to provide further insight on the contact biomechanics of the trapeziometacarpal joint by in vivo assessment of healthy and osteoarthritic subjects. Methods The hands of 16 healthy women and 6 women with trapeziometacarpal osteoarthritis were scanned in positions of maximal thumb extension, flexion, abduction and adduction during three isometric tasks (lateral key pinch, power grasp and jar twist) and in thumb rest posture (relaxed neutral). Three-dimensional surface models of the trapezium and first metacarpal were created for each thumb configuration. The articular surface of each bone was measured in the neutral posture. A computed tomography-based proximity mapping algorithm was developed to calculate the distance between opposing joint surfaces, which was used as a surrogate for intra-articular stress. Findings Distinct proximity patterns were observed across tasks with a recurrent pattern reported on the volar aspect of the first metacarpal. The comparison between healthy and arthritic subjects showed a significantly larger articular area, in parallel with a significant joint space narrowing and an increase in proximity area in arthritic subjects. We also observed severe articular deformations in subjects with late stage osteoarthritis. Interpretation This study has increased our insight in the contact biomechanics of the trapeziometacarpal joint during tasks and positions of daily life in healthy and arthritic subjects, which might contribute to a better understanding of the occurrence mechanisms of degenerative diseases such as osteoarthritis. [ABSTRACT FROM AUTHOR]

Background Sex and body mass may influence knee biomechanics associated with poor total knee arthroplasty (TKA) outcomes for knee osteoarthritis (OA). This study aimed to determine if gait differed between men and women, and overweight and class I obese patients with severe knee OA awaiting TKA. Methods 34 patients with severe knee OA (average age 70.0 (SD 7.2) years, body mass index 30.3 (4.1 kg/m 2 )) were recruited from a TKA waiting list. Three-dimensional gait analysis was performed at self-selected walking speed. Comparisons were made between men and women, and overweight (body mass index (BMI) 25.0–29.9 kg/m 2 ) and class I obese (BMI 30.0–34.9 kg/m 2 ) participants. Biomechanical outcomes included absolute and body size-adjusted peak knee adduction moment (KAM), KAM impulse, peak knee flexion moment, as well as peak knee flexion and varus-valgus angles, peak varus-valgus thrust, and peak vertical ground reaction force (GRF). Findings Men had a higher absolute peak KAM, KAM impulse and peak GRF compared to women, and this sex-difference in frontal plane moments remained after adjusting for body size. However, when additionally adjusting for static knee alignment, differences disappeared. Knee biomechanics were similar between obesity groups after adjusting for the greater body weight of those with class I obesity. Interpretation Men had greater KAM and KAM impulse even after adjustment for body size; however adjustment for their more varus knees removed this difference. Obesity group did not influence knee joint kinematics or moments. This suggests sex- and obesity-differences in these variables may not be associated with TKA outcomes. [ABSTRACT FROM AUTHOR]

Background Biomechanical deviations long (approx. 5 years) after anterior cruciate ligament reconstruction have not been quantified in males, despite their distinct risk profile as compared to females. These deviations can indicate altered joint loading during chronic, repetitive motions. Methods Cross-sectional study, comparing kinematic and kinetic variables between 15 male anterior cruciate ligament reconstructed patients and 15 healthy controls. During walking and running gait, measurements were taken of impact dynamics, knee and hip sagittal plane angles and moments, and knee varus angles and adduction moments. Findings Comparing affected limbs to control limbs, significantly lower maximum ( P = 0.001) and initial ( P = 0.003) loading rates were found during running, but not in walking. Hip angles were lower for affected limbs of patients compared to the control group ( P = 0.039) in walking, but not during running. Between-limb comparisons showed important differences in symmetry of the affected patients. Maximum force during running was higher in the unaffected limb ( P = 0.015), which was linked with a higher loading rate ( P = 0.008). Knee flexion angle was reduced by 2° on average for the affected limb during running ( P = 0.010), and both walking and running knee and hip moments showed differences. Knee varus angle showed a 1° difference during walking ( P < 0.001), but not during running. Knee adduction moment was significantly lower (more valgus) during both walking and running. Interpretation Male anterior cruciate ligament reconstructed patients demonstrate persistent, clinically important gait asymmetries and differences from healthy controls long after surgery in kinematics, kinetics, and impact biomechanics. [ABSTRACT FROM AUTHOR]

Non-level transfers are some of the most demanding tasks for manual wheelchair users. Safely performing these transfer tasks may be needed for maintaining long-term upper limb health. This cross-sectional study aimed to examine the influence of gender on the head-hip technique and lead arm kinematics during multi-height transfers in manual wheelchair users. Motion analysis was used to obtain lead-arm shoulder kinematics (flexion/extension and abduction/adduction) and trunk flexion during level, uphill, and floor-to-table transfers in full-time manual wheelchair users. Twelve male (N = 12) and fifteen female (N = 15) manual wheelchair users with a mean age of 23 ± 5 years and no signs of shoulder pain participated in the study. Lead-arm shoulder flexion and abduction increased as vertical displacement requirements increased during the various transfer tasks (p < 0.01). Women displaced greater trunk flexion during level transfers at approaching significant levels (p = 0.07). During uphill transfers, women displayed significantly greater trunk flexion than men (p < 0.05). Manual wheelchair users use unique kinematic requirements when using the head-hip during level and non-level transfers. Women may be at decreased risk of chronic shoulder pain due to a greater use of the head-hip technique during non-level transfers. Nonetheless, more research that integrates kinetics and strength assessments during non-level transfer biomechanical analyses is needed to better understand technical requirements of non-level transfers in manual wheelchair users. • Non-level transfers are essential tasks of daily living for manual wheelchair users. • Understanding shoulder and trunk biomechanics may help in teaching transfers. • Increased shoulder abduction and flexion may be needed to complete non-level transfer. • Women engage in greater trunk flexion than men during non-level transfers. [ABSTRACT FROM AUTHOR]

Background Individuals who suffered a lower limb injury have an increased risk of developing knee osteoarthritis. Early diagnosis of osteoarthritis and the ability to track its progression is challenging. This study aimed to explore links between self-reported knee osteoarthritis outcome scores and biomechanical gait parameters, whether self-reported outcome scores could predict gait abnormalities characteristic of knee osteoarthritis in injured populations and, whether scores and biomechanical outcomes were related to osteoarthritis severity via Spearman's correlation coefficient. Methods A cross-sectional study was conducted with asymptomatic participants, participants with lower-limb injury and those with medial knee osteoarthritis. Spearman rank determined relationships between knee injury and outcome scores and hip and knee kinetic/kinematic gait parameters. K-Nearest Neighbour algorithm was used to determine which of the evaluated parameters created the strongest classifier model. Findings Differences in outcome scores were evident between groups, with knee quality of life correlated to first and second peak external knee adduction moment (0.47, 0.55). Combining hip and knee kinetics with quality of life outcome produced the strongest classifier (1.00) with the least prediction error (0.02), enabling classification of injured subjects gait as characteristic of either asymptomatic or knee osteoarthritis subjects. When correlating outcome scores and biomechanical outcomes with osteoarthritis severity only maximum external hip and knee abduction moment (0.62, 0.62) in addition to first peak hip adduction moment (0.47) displayed significant correlations. Interpretation The use of predictive models could enable clinicians to identify individuals at risk of knee osteoarthritis and be a cost-effective method for osteoarthritis screening. [ABSTRACT FROM AUTHOR]

Background Gait instability often limits post-stroke function, although the mechanisms underlying this instability are not entirely clear. Our recent work has suggested that one possible factor contributing to post-stroke gait instability is a reduced ability to accurately control foot placement. The purpose of the present experiments was to investigate whether post-stroke gait function is related to the ability to accurately abduct and adduct the hip, as required for accurate foot placement. Methods 35 chronic stroke survivors and 12 age-matched controls participated in this experiment. Participants performed hip oscillation trials designed to quantify hip abduction/adduction accuracy, in which they lay supine and moved their leg through a prescribed range of motion in time with a metronome. Stroke survivors also performed overground walking trials at their self-selected speed. Findings 28 of the 35 stroke survivors had sufficient active range of motion to perform the prescribed hip oscillation task. In comparison to controls, these 28 stroke survivors were significantly less accurate at matching the abduction target, matching the adduction target, and moving in time with the metronome. Across these stroke survivors, a multiple regression revealed that only paretic hip abduction accuracy made a unique contribution to predicting paretic step width and paretic step period, metrics of gait performance. Interpretation The present results demonstrate that the ability to accurately abduct the hip is related to post-stroke gait performance, as predicted from a model-based gait stabilization strategy. Therefore, interventions designed to improve lower limb movement accuracy may hold promise for restoring post-stroke gait stability. [ABSTRACT FROM AUTHOR]

Background Strengthening of the hip and trunk muscles has the potential to change lower limb kinematic patterns, such as excessive hip medial rotation and adduction during weight-bearing tasks. This study aimed to investigate the effect of hip and trunk muscles strengthening on hip muscle performance, hip passive properties, and lower limb kinematics during step-down task in women. Methods Thirty-four young women who demonstrated dynamic knee valgus during step-down were divided into two groups. The experimental group underwent three weekly sessions of strengthening exercises for eight weeks, and the control group continued their usual activities. The following evaluations were carried out: (a) isokinetic maximum concentric and eccentric work of hip lateral rotators, (b) isokinetic hip passive torque of lateral rotation and resting transverse plane position, and (c) three-dimensional kinematics of the lower limb during step-down. Findings The strengthening program increased concentric ( P < 0.001) and eccentric ( P < 0.001) work of hip lateral rotators, and changed hip resting position toward lateral rotation ( P < 0.001). The intervention did not significantly change hip passive torque ( P = 0.089, main effect). The program reduced hip ( P = 0.002), thigh ( P = 0.024) and shank ( P = 0.005) adduction during step-down task. Hip, thigh and knee kinematics in transverse plane and foot kinematics in frontal plane did not significantly modify after intervention ( P ≥ 0.069, main effect). Interpretation Hip and trunk strengthening reduced lower limb adduction during step-down. The changes in hip maximum work and resting position may have contributed to the observed kinematic effects. [ABSTRACT FROM AUTHOR]

Background: Gait adaptations, including toe out gait, have been proposed as treatments for knee osteoarthritis. The clinical application of toe out gait, however, is unclear. This study aims to identify the changes in Knee adduction moment in varus knee deformity assessing toe out gait as an alternative to high tibial osteotomy, and if any change in dynamic loading persists post operatively, when anatomical alignment is restored. Methods: Three-dimensional motion analysis was performed on 17 patients with medial compartment knee osteoarthritis and varus deformity prior to undergoing high tibial osteotomy, 13 patients were assessed post-operatively, and results compared to 13 healthy controls. Findings: Pre-operatively, there was no significant difference between natural and toe out gait for measures of knee adduction moment. Post high tibial osteotomy, first (2.70 to 1.51% BW·h) and second peak (2.28 to 1.21% BW·h) knee adduction moment were significantly reduced, as was knee adduction angular impulse (1.00 to 0.52% BW·h·s), to a healthy level. Adopting toe out gait post-operatively reduced the second peak further to a level below that of healthy controls. Interpretation: Increasing the foot progression angle from 20° (natural) to 30° in isolation did not significantly alter the knee adduction moment or angular impulse. This suggests that adopting a toe out gait, in isolation, in an already high natural foot progression angle, is not of benefit. Adopting toe out gait post-operatively, however, resulted in a further reduction in the second peak to below that of the healthy control cohort, however, this may increase lateral compartment load. [ABSTRACT FROM AUTHOR]

Background: The elevated vacuum suspension system has demonstrated unique health benefits for amputees, but the effect of vacuum pressure values on gait characteristics is still unclear. The purpose of this study was to investigate the effects of elevated vacuum levels on temporal parameters, kinematics and kinetics for unilateral transtibial amputees. Methods: Three-dimensional gait analysis was conducted in 9 unilateral transtibial amputees walking at a controlled speed with five vacuum levels ranging from 0 to 20 in Hg, and also in 9 able-bodied subjects walking at self-preferred speed. Repeated ANOVA and Dunnett's t-test were performed to determine the effect of vacuum level and limb for within subject and between groups. Findings: The effect of vacuum level significantly affected peak hip external rotation and external knee adduction moment. Maximum braking and propulsive ground reaction forces generally increased for the residual limb and decreased for the intact limb with increasing vacuum. Additionally, the intact limb experienced an increased loading due to gait asymmetry for several variables. Interpretation: There was no systematic vacuum level effect on gait. Higher vacuum levels, such as 15 and 20 in Hg, were more comfortable and provided some relief to the intact limb, but may also increase the risk of osteoarthritis of the residual limb due to the increased peak external hip and knee adduction moments. Very low vacuum should be avoided because of the negative effects on gait symmetry. A moderate vacuum level at 15 in Hg is suggested for unilateral transtibial amputees with elevated vacuum suspension. [ABSTRACT FROM AUTHOR]

The precise role of the acromioclavicular and coracoclavicular ligaments during shoulder motion is unclear. We evaluate changes in the stress-strain distribution of the acromioclavicular joint's ligaments during different shoulder passive motion positions. A 3D acromioclavicular joint model was reconstructed. A constitutive hyperelastic model was used for the ligaments. The kinematics of the shoulder girdle was taken to simulate shoulder abduction (Motion 1) and horizontal adduction (Motion 2). A computer-generated quasi-static and non-linear finite element model was used to predict the 3D stress-strain distribution pattern of the acromioclavicular ligament and the coracoclavicular ligament complex. In motion 1, from 20 to 90° the peak von Mises stress was found in the conoid (4.14 MPa) and the anteroinferior bundle (2.46 MPa), while from 90 to 120° it was found in the conoid and the trapezoid. However, there were no significant differences between the mean stress values between anteroinferior bundle and trapezoid throughout the motion (p = 0.98). In Motion 2, from 20 to 80° the maximum equivalent elastic strain was found in the anteroinferior bundle (0.68 mm/mm) and the conoid (0.57 mm/mm), while from 80 to 100° it was higher in the conoid (0.88 mm/mm) than in the anteroinferior bundle (0.77 mm/mm). The coracoclavicular ligament complex demonstrated a high stress-strain concentration during simulated passive shoulder abduction. Additionally, it was shown that the acromioclavicular ligament plays an important role in joint restraint during passive horizontal adduction, changing the primary role with the trapezoid and conoid at different motion intervals. • The conoid ligament is the primary stabilizer in shoulder abduction. • Anteroinferior bundle is a secondary restrictor up to 90° of shoulder abduction. • Trapezoid is primary stabilizer up to 80° of shoulder horizontal adduction. • The anteroinferior bundle and coracoclavicular ligaments switch roles in adduction. • Superoposterior bundle has a minor stabilizer role in both motions. [ABSTRACT FROM AUTHOR]

Background : Varus thrust, defined as an abrupt increase of the knee varus angle during weight-bearing in gait, has been shown to be present in patients with moderate to severe knee osteoarthritis and is considered to be one of the risk factors for progression of symptomatic medial knee osteoarthritis. We evaluated the presence and magnitude of varus thrust and its relation with the Knee Adduction Moment in women with early medial knee osteoarthritis, and compared it to that in a group of controls and in a group of subjects with established medial knee osteoarthritis. Methods : Twenty-seven women with early medial knee osteoarthritis, 20 women with established medial knee osteoarthritis and 24 asymptomatic controls were evaluated. Varus thrust was estimated as an increase of the knee varus angle during the weight-bearing phase of gait at self-selected speed, assessed by 3D motion analysis. Findings : Varus thrust was significantly higher in both early and established osteoarthritis groups compared to the control group ( P < 0.001), but not different between osteoarthritis groups. While the knee adduction moments were higher than controls only in the established osteoarthritis group, the magnitude of varus thrust was significantly correlated with the second peak knee adduction moment. Interpretation : Higher varus thrust was found both in early and established stages of knee osteoarthritis, suggesting that problems with dynamic stabilization of the knee are present early in the development of knee osteoarthritis. This highlights the necessity of considering dynamic alignment in rehabilitation already in the early stages of the disease. [ABSTRACT FROM AUTHOR]

Background Leg length discrepancy greater than 1 cm increases odds of progressive knee osteoarthritis in the shorter limb. Methods Biomechanical data of 15 knee osteoarthritis participants were collected while they walked under two conditions: (1) control — wearing thick sandals; (2) short limb — wearing a thin sandal on the osteoarthritic limb and a thick sandal on the contralateral limb. The thick and thin sandals had 1.45 cm of thickness difference. The knee osteoarthritis limb was analyzed for both conditions. Ankle, knee, hip, pelvis and trunk kinematics and moments were measured with a motion and force capture system. Principal component analysis and mean hypothesis' tests were used to compare the conditions. Findings The short limb condition reduced rearfoot plantarflexion in loading response and increased plantarflexion in late stance (p < 0.001), increased ankle dorsiflexion moment (p = 0.003), increased knee flexion angle in loading response and delayed knee flexion in late stance (p = 0.001), increased knee extension moment in loading response and increased knee flexion moment in terminal stance (p = 0.023), reduced hip extension moment in early stance and reduced hip flexion moment in late stance (p < 0.001), reduced knee adduction moment (p = 0.015), reduced hip adduction angle (p = 0.001) and moment (p = 0.012) and increased pelvic (p = 0.023) and trunk (p = 0.001) external rotation. Interpretation Mild leg length discrepancy affects the entire kinetic chain of individuals with knee osteoarthritis during gait, increasing knee sagittal plane loading, which helps to explain why mild leg length discrepancy accelerates knee osteoarthritis progression. Mild leg length discrepancy should not be overlooked in knee osteoarthritis individuals. [ABSTRACT FROM AUTHOR]

Hip torque ratios are considered a useful measure for patients with hip pain. However, evidence regarding this measure for patients with femoroacetabular impingement syndrome is scarce. The primary aim of this study was to compare hip external-internal rotation and abduction-adduction torque ratios between patients with femoroacetabular impingement syndrome and asymptomatic individuals. The secondary aim was to compare hip torque ratios between the asymptomatic group and femoroacetabular impingement syndrome patients grouped according to the severity of symptoms and functional limitations. Hip abduction-adduction and external-internal rotation torque ratios of 134 individuals with femoroacetabular impingement syndrome and 134 asymptomatic matched controls was assessed through isokinetic testing. Severity of symptoms and functional limitations was assessed through the iHOT-33. Mann Whitney U and Kruskall-Wallis tests were used to compare hip torque ratios between asymptomatic individuals and patients with femoroacetabular impingement syndrome and to patients with femoroacetabular impingement syndrome with different severities of symptoms and functional limitations. No differences were identified in hip abduction-adduction (U = 7659.5, p = 0.192) and external-internal rotation (U = 8787.5, p = 0.764) torque ratios between patients with femoroacetabular impingement syndrome and asymptomatic individuals. Hip abduction-adduction torque ratio was higher (p = 0.0127) in patients with a severe state (median = 1.80, IQR = 0.61) when compared to asymptomatic individuals (median = 1.52, IQR = 0.45) (moderate effect size, r = 0.45). Patients with severe symptoms and functional limitations related to FAI syndrome presented greater hip abduction-adduction torque ratio than asymptomatic individuals, suggesting a decreased adduction torque capacity relative to abduction torque in this subgroup of femoroacetabular impingement. • Hip transverse plane muscle imbalance is absent in femoroacetabular impingement. • Hip torque ratios can discriminate a severe femoroacetabular impingement state. • Greater abductor relative to adductor torque in severe femoroacetabular impingement. [ABSTRACT FROM AUTHOR]

To differentiate gait strategies per knee osteoarthritis and self-reported walking difficulty during self-selected regular and fast gait speeds. We hypothesize that knee osteoarthritis gait characteristics during self-selected regular and fast gait speeds will be most accentuated by the osteoarthritis and walking difficulty group, followed by osteoarthritis and no walking difficulty, and least in the control group. Prospective study of community-dwelling older adults (n = 39) who walk at functional speeds (≥1.0 m per second) were age and sex matched across the three groups. Gait strategies including knee excursion and moments, muscle activation and co-contraction, and limb dynamics (linear acceleration and jerk) were compared between groups during self-selected regular and fast gait speed trials. Significant group differences were defined as P < 0.05 and an effect size greater than small. Based on walking difficulty, adduction moments (P -range = 0.00–0.03; effect size range, r = 0.42–0.52) and lateral quadriceps-gastrocnemius co-activations (P = 0.01; r = 0.36) were significant during regular gait speeds; and extension (P = 0.03;d = 0.59) and adduction (P-range = 0.00–0.02;d = 0.86; r = 0.40) moments were significant during fast trials. Per knee osteoarthritis presence, adduction moment(P = 0.01; r = 0.49), medial-quadriceps (P = 0.00;d = 1.04; r = 0.61), lateral-hamstrings (P = 0.04;d = 0.55), medial-gastrocnemius (P = 0.02; r = 0.40), medial quadriceps-hamstrings (P = 0.02; r = 0.38), medial quadriceps-gastrocnemius (P = 0.00; r = 0.56), and all limb dynamics (P = 0.00–0.01;d = 1.13–1.18; r = 0.35–0.47) were significant during regular gait speeds. Extension excursion (P = 0.02;d = 0.63), adduction moment (P = 0.01;d = 0.85) and medial-quadriceps (P = 0.01; r = 0.38) were significant during fast trials. Many gait strategies during regular speeds that differ per walking difficulty and knee osteoarthritis attenuated at fast speeds. Perhaps gait training at fast speeds for those with knee osteoarthritis related walking difficulty is biomechanically and functionally beneficial. • Self-report walking difficulty is associated with greater knee adduction moment. • Strategies to limit adduction moment may improve walking ability. • Fast walking dampers knee osteoarthritis and walking difficulty strategies. • Fast walking maybe beneficial for knee osteoarthritis and walking difficulty. [ABSTRACT FROM AUTHOR]

Background Several hypotheses have been proposed to explain the pathomechanisms underlying patellofemoral pain (PFP). Concurrent evaluation of lower limb mechanics in the same PFP population is needed to determine which may be more important to target during rehabilitation. This study aimed to investigate possible differences in rearfoot eversion, hip adduction, and knee flexion during stair ascent; the relationship between these variables; and the discriminatory capability of each in identifying females with PFP. Method Thirty-six females with PFP and 31 asymptomatic controls underwent three-dimensional kinematic analyses during stair ascent. Between-group comparisons were made for peak rearfoot eversion, hip adduction, and knee flexion. Pearson's correlation coefficients were calculated to evaluate relationships among these parameters. Receiver operating characteristic curves were applied to identify the discriminatory capability of each. Findings Females with PFP ascended stairs with reduced peak knee flexion, greater peak hip adduction and peak rearfoot eversion. Peak hip adduction (> 10.6°; sensitivity = 67%, specificity = 77%) discriminated females with PFP more effectively than rearfoot eversion (> 5.0°; sensitivity = 58%, specificity = 67%). Reduced peak hip adduction was found to be associated with reduced peak knee flexion (r = 0.54, p = 0.002) in females with PFP. Interpretation These findings indicate that proximal, local, and distal kinematics should be considered in PFP management, but proximally targeted interventions may be most important. The relationship of reduced knee flexion with reduced hip adduction also indicates a possible compensatory strategy to reduce patellofemoral joint stress, and this may need to be addressed during rehabilitation. [ABSTRACT FROM AUTHOR]

Background Unanticipated cutting tasks which do not allow for pre-planning of a movement have been reported to promote knee mechanics which may increase the risk of anterior cruciate ligament injury. Fatigue has also been reported to have similar effects. Athletes must often perform unanticipated tasks when they are fatigued. Previous studies have reported that the effects of anticipation become more prominent as an athlete progresses through a fatigue protocol. However, the protocols previously utilized may not mimic the demands of sports participation. Methods Three-dimensional knee joint kinematics and kinetics were collected from 13 female athletes while they performed a run-and-cut task, before and after completion of an intermittent shuttle run. Trials were further divided (pre-planned, unanticipated) to assess the effects of anticipation. Findings There were no significant interactions between the effects of fatigue and anticipation for the peak knee angles or moments of the knee joint in any plane. Subjects did demonstrate a 68% increase in their peak knee abduction angles following completion of the intermittent shuttle run. Anticipation also had a significant effect on the mechanics of the knee in all planes. Most notably, there was a 23% increase in peak knee abduction angles and a 33% increase in the peak internal knee adduction moments. Interpretation Both fatigue and anticipation promoted knee mechanics which are associated with an increased risk of knee injury. However, it does not appear that their effects combine when athletes are at a level of fatigue which is thought to reflect sports participation. [ABSTRACT FROM AUTHOR]

Background Lateral hip pain during walking is a feature of gluteal tendinopathy but little is known how walking biomechanics differ in individuals with gluteal tendinopathy. This study aimed to compare walking kinematics and kinetics between individuals with and without gluteal tendinopathy. Methods Three-dimensional walking-gait analysis was conducted on 40 individuals aged 35 to 70 years with unilateral gluteal tendinopathy and 40 pain-free controls. An analysis of covariance was used to compare kinematic and kinetic variables between groups. Linear regression was performed to investigate the relationship between kinematics and external hip adduction moment in the gluteal tendinopathy group. Findings Individuals with gluteal tendinopathy demonstrated a greater hip adduction moment throughout stance than controls (standardized mean difference ranging from 0.60 (first peak moment) to 0.90 (second peak moment)). Contralateral trunk lean at the time of the first peak hip adduction moment was 1.2 degrees greater ( P = 0.04), and pelvic drop at the second peak hip adduction moment 1.4 degrees greater ( P = 0.04), in individuals with gluteal tendinopathy. Two opposite trunk and pelvic strategies were also identified within the gluteal tendinopathy group. Contralateral pelvic drop was significantly correlated with the first ( R = 0.35) and second peak ( R = 0.57) hip adduction moment, and hip adduction angle with the second peak hip adduction moment ( R = − 0.36) in those with gluteal tendinopathy. Interpretation Individuals with gluteal tendinopathy exhibit greater hip adduction moments and alterations in trunk and pelvic kinematics during walking. Findings provide a basis to consider frontal plane pelvic control in the management of gluteal tendinopathy. [ABSTRACT FROM AUTHOR]

Our objective was to investigate kinematic and kinetic characteristics and changes in muscle function in individuals with patellofemoral osteoarthritis compared to healthy individuals. Searches were performed of the Medline, Embase, Web of Science, The Cochrane Library, LILACS, and SciELO databases until May of 2022 for observational studies comparing individuals with patellofemoral osteoarthritis to a control group. The PRISMA guidelines and recommendations of the Cochrane Collaboration were followed. The GRADE approach was used to analyze and synthesize the level of evidence. Fourteen studies were included, involving a total of 594 participants (360 with patellofemoral osteoarthritis and 234 controls). The level of evidence for pelvis, hip adduction and knee abduction angles at 45° of knee flexion during the single-leg squat, and knee flexion angle during the task of walking was very low. Regarding muscle strength, the level of evidence for isometric strength of the hip abductors, extensors and external rotators, and concentric strength of the knee extensors and flexors was very low. It was not possible to synthesize any type of evidence for kinetic, electromyography, or muscle volume variables. The level of evidence was very low for all synthesized evidence for kinematic and muscle strength variables. However, individuals with patellofemoral osteoarthritis have lower isometric strength of the hip abductor muscles. Further studies with adequate adjustment for confounding factors, such as the non-inclusion of individuals with osteoarthritis in the tibiofemoral compartment concomitant to patellofemoral osteoarthritis, are needed to gain a better understanding of the clinical characteristics of patellofemoral osteoarthritis. • The level of evidence was very low for all synthesized evidence for kinematics. • The level of evidence was very low for all synthesized evidence for muscle strength. • Kinetics evaluation is heterogeneous to date. [ABSTRACT FROM AUTHOR]

Background Lateral foot wedges represent a biomechanical intervention aimed at reducing medial knee loads. However, the effects of varying wedge amounts on biomechanical variables and orthotic comfort have not been systematically studied. Further, arch height may influence the comfort of laterally wedged devices. Therefore, the primary purpose of this study was to examine the effect of incrementally increasing lateral wedge amounts on knee adduction moment parameters and subjective comfort. The secondary purpose was to relate arch height measures to the comfort of the devices. Methods Twenty-five healthy subjects underwent three-dimensional instrumented gait analysis testing using seven inclinations of lateral wedging (0°, 2°, 4°, 6°, 8°, 10°, 12°). Subjects reported comfort level for each orthotic condition. Arch heights were measured in standing and sitting, and rigidity index and stiffness were calculated. Findings The knee adduction moment decreased with wedge amounts up to 6°, but more aggressive amounts did not yield additional reductions. Comfort ratings did not change from baseline until wedge amounts exceeded 8°. In addition, arch height measures, arch rigidity index and stiffness did not relate to the comfort of the orthotic device regardless of the wedge amount. Interpretation Knee adduction moment decreased with mild wedge amounts while maintaining comfort. Wedge amounts greater than 6° yielded little additional mechanical benefit and amounts greater than 8° compromised comfort. It appears that 4°–6° of lateral wedging are optimal in regard to desirable biomechanical change and comfort level in healthy individuals. [ABSTRACT FROM AUTHOR]

Background The primary aim of this study was to compare knee and hip dynamic muscle strength of individuals with femoroacetabular impingement (FAI) syndrome scheduled for hip arthroscopy with healthy controls. Our secondary aim was to compare hip and knee muscle strength between male and female patients with FAI syndrome. Methods One hundred and thirty-four individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy and 134 healthy controls matched for sex and age (within 5 years range) underwent an isokinetic assessment of knee extension and flexion and hip abduction, adduction, external rotation and internal rotation dynamic muscle strength. Two MANOVAs were conducted to compare isokinetic peak torque and total work between groups and sexes. Findings Individuals with femoroacetabular impingement syndrome demonstrated lower values of all variables representing knee and hip isokinetic peak torque and total work measures when compared to healthy controls, with differences ranging from 0.09 Nm/kg (95%CI: 0.06–0.12 Nm/kg) to 0.64 Nm/kg (95%CI: 0.49–0.79 Nm/kg). Female participants from both FAI syndrome and control group showed less knee and hip muscle strength compared to male participants. There was no significant interaction between group and sex regarding knee or hip isokinetic peak torque and total work (p > 0.05). Interpretation Individuals with femoroacetabular impingement syndrome scheduled for hip arthroscopy present impairments in knee or hip dynamic muscle strength when compared to controls. Female participants present less knee and hip muscular strength compared to male participants, these between-sex differences are similar for both FAI syndrome and control group participants. • Participants with femoroacetabular impingement presented knee and hip strength impairments. • Deficits in knee muscle strength presented larger between group effect sizes than in hip strength. • Isokinetic total work measures were able to discriminate muscle strength impairments. • Muscle strength impairments were regardless of sex. [ABSTRACT FROM AUTHOR]

Hip muscle weakness and altered hip biomechanics during walking are often observed in people with femoroacetabular impingement syndrome, although little is known about biomechanics during higher impact tasks. The aim of our study was to explore relationships between hip muscle strength and hip biomechanics during running in people with femoroacetabular impingement syndrome, including exploring sex as an effect-modifier of this relationship. Forty-two adults with unilateral femoroacetabular impingement syndrome (20 females; age 18-50 years; alpha angle ≥60°) completed assessments of hip muscle strength and hip biomechanics during running. Strength was assessed using a hand-held dynamometer for the hip flexors, extensors, abductors, adductors, internal rotators, and external rotators. Hip biomechanics were assessed during overground running (3–3.5 m/s) using three-dimensional motion capture and a force plate. Linear models assessed the relationships between hip strength and hip biomechanics of the symptomatic limb, controlling for body mass and running velocity along with an interaction term (strength*sex). A significant negative relationship was observed between hip external rotator strength and hip frontal plane range of motion (i.e., excursion), independent of sex (estimate = −0.039, 95%CI −0.071 to −0.008, P = 0.02). Four sex-specific interactions were observed, with a significant positive relationship between hip external rotator strength and peak hip extension moment in women (estimate = −0.413, 95%CI −0.713 to −0.114, P = 0.01) but not in men. We found significant relationships between hip external rotator strength and stance phase running biomechanics, providing further understanding on two impaired physical measures that may inform exercise-based management strategies in femoroacetabular impingement syndrome. • Hip weakness and altered movement exist with femoroacetabular impingement syndrome. • Associations between muscle strength and running biomechanics were explored. • Stronger hip external rotators were associated with less hip frontal plane motion. • Significant sex-specific interactions were observed in some associations. • Our results may help to inform exercise-based management strategies. [ABSTRACT FROM AUTHOR]

Walking can be a challenging task for individuals with knee osteoarthritis and many older adults. The purpose was to determine the immediate effect of a frontal plane perturbation bout during walking on knee biomechanics and muscle activation patterns in these groups. 44 asymptomatic older adults and 32 individuals with knee osteoarthritis were recruited. Sagittal and frontal plane knee biomechanics and muscle activation levels were calculated and recorded during treadmill walking. After a baseline collection at 6-min, a random series of unexpected medial/lateral walkway surface perturbations were delivered over approximately 24 min. Data was collected immediately after the perturbations. Discrete measures extracted from biomechanical waveforms, and principal component analysis to analyze muscle activation were utilized to determine time effects and interactions using analysis of variance models (alpha = 0.05). After the perturbation bout, sagittal plane range of motion was significantly increased in the osteoarthritis group (Effect Size = 0.24) and in both groups peak knee adduction moment (Effect Size = 0.10) and difference between peak flexion and extension moments (Effect Size = 0.16) were significantly increased. Muscle amplitudes in both groups were significantly reduced (PP1-scores) after perturbation bout, whereas significant time-based gait cycle activation pattern alterations identified by PP2- and PP3-scores were related to group and muscle assignment. Perturbations were tolerated by all participants, resulting in significant alterations to biomechanical outcomes and muscle activation levels and patterns. Demand on the knee joint was not increased after perturbations. Gait perturbation training in these groups may be feasible using a frontal plane perturbation bout. • Osteoarthritis and asymptomatic groups responded similarly to gait perturbations. • Minimal changes to knee biomechanics after gait perturbations. • Reduced and less prolonged muscle activation after gait perturbations • Results support investigations in gait perturbation training for knee osteoarthritis [ABSTRACT FROM AUTHOR]

Abstract: Background: The metabolic cost and cognitive demand of altering natural gait have not been well studied. The purpose of this investigation was to assess three modified patterns – toe out, ipsilateral trunk lean and a medial weight shift at the foot – on the basis of 1) medial knee joint load reduction, 2) metabolic cost of performance and 3) subject perception of task difficulty. Methods: 12 healthy individuals underwent 3 dimensional motion analysis and metabolic testing to assess the gait mechanics and energy expenditure of natural gait and the three experimental gait patterns, performed to a self-selected moderate degree. Walking speed was controlled. Perceived workload was assessed using the NASA Task Load Index. Findings: Trunk lean significantly reduced first peak knee adduction moment (↓32%, P <0.001) as well as KAM impulse (↓35%, P <0.001), but was costly in terms of energy expenditure (↑11%, P <0.001) and perceived workload (↑1178%, P <0.001). A moderate toe-out pattern significantly reduced the second peak knee adduction moment (↓32%, P <0.001) and KAM impulse (↓14%, P =0.026), but had no effect on the first peak. Conversely, toe-out was least demanding in terms of additional energy expenditure (↑2%, P =0.001) and perceived workload (↑314%, P =0.001). Medial shift did not reduce knee adduction moment. Interpretation: The prioritization of joint load reduction versus additional metabolic and cognitive demands could play a substantial role in the clinical decision making process of selecting a modified gait pattern. [Copyright &y& Elsevier]

Abstract: Background: Only very few publications dealing with shoulder arthrodesis after bone resection procedures and no biomechanical studies are available. The presented biomechanical analysis should ascertain the type of arthrodesis with the highest primary stability in different bone loss situations. Methods: On 24 fresh cadaveric shoulder specimens three different bone loss situations were investigated under the stress of abduction, adduction, anteversion and retroversion without destruction by the use of a material testing machine. In each of the testings a 16-hole reconstruction plate was used and compared to arthrodesis with an additional dorsal 6-hole plate. Findings: The primary stability of shoulder arthrodesis with a 16-hole reconstruction plate after humeral head resection could be increased significantly if an additional dorsal plate was used. However, no significant improvement with the additional plate was detected after resection of the acromion. Of all investigated forms, arthrodesis after humeral head resection with additional plate showed the highest and arthrodesis after humeral head resection without additional plate showed the lowest force values. The mean values for forces achieved in abduction and adduction were considerably higher than those in anteversion and retroversion. Interpretation: There are no consistent specifications of arthrodesis techniques after resection situation available, thus the presented biomechanical testings give important information about the most stable form of arthrodesis in different types of bone loss. These findings provide an opportunity to minimize complications such as pseudarthrosis for a satisfying clinical outcome. [Copyright &y& Elsevier]

Abstract: Background: Laterally wedged insoles have controversial effect in treating medial compartment knee osteoarthritis. This study examined the effects of unilateral and bilateral use of insoles having medial arch supports and of different inclinations on the frontal plane external hip, knee, subtalar moments and pelvic alignment. Methods: Kinetic and kinematic gait parameters were collected from 21 patients with primary medial knee osteoarthritis. The insoles'' inclinations were 0, 6 and 11°, where each of the 6° and 11° was used once unilaterally and another bilaterally while the 0° was used bilaterally as a control. Findings: The Multivariate Analysis of Variance revealed significant increase in the external subtalar eversion moment using either of the 6° or 11° laterally wedged vs the 0° non-wedged insole conditions (P =0.003). Moreover, there were significant increases in the external eversion moment using the 11° vs the 6° insole conditions (P <0.05). However, there were no significant differences for the remaining tested variables (P >0.05). The bivariate correlations revealed significant negative correlations between the subtalar eversion and knee adduction moments (r=−0.409, P =0.000) and the subtalar eversion and hip adduction moments (r=−0.226, P =0.049), and positive correlation between the hip and knee adduction moments (r=0.268, P =0.019). Interpretation: The non-significant reduction in the external knee adduction moment may question the efficacy of using wedged insoles having medial arch supports in treating patients with medial knee osteoarthritis. Additionally, using such insoles did not produce appreciable mechanical effects on remote articulations as the hip and pelvis. [Copyright &y& Elsevier]

Abstract: Background: Osteoarthritis affects the whole body, thus biomechanical effects on other joints should be considered. Unloading knee braces could be effective for knee osteoarthritis, but their effects on the contralateral knee and bilateral hip joints remain unknown. This study investigated the effects of bracing on the kinematics and kinetics of involved and contralateral joints during gait. Methods: Nineteen patients with medial compartment knee osteoarthritis were analysed. Kinematics and kinetics of the knee and hip joints in frontal and sagittal planes were measured during walking without and with bracing on the more symptomatic knee. Findings: The ipsilateral hip in the braced condition showed a lower adduction angle by an average of 2.58° (range, 1.05°–4.16°) during 1%–49% of the stance phase, and a lower abduction moment at the second peak during the stance phase than the hip in the unbraced condition (P <0.05 and P <0.005, respectively). With bracing, the contralateral hip showed a more marked peak extension moment and lower abduction moment at the first peak (P <0.05), and the contralateral knee adduction angle increased by an average of 0.32° (range, 0.21°–0.45°) during 46%–55% of the stance phase (P <0.05), compared to no bracing. Interpretation: Unloading bracing modified the contralateral knee adduction angle pattern at a specific time point during gait. It also affected the frontal plane on the ipsilateral hip and the frontal and sagittal planes on the contralateral hip joint. Consideration should be provided to other joints when treating knee osteoarthritis. [Copyright &y& Elsevier]

Abstract: Background: Arthroscopic partial meniscectomy patients are at increased risk of developing knee osteoarthritis. This population, particularly those with weaker quadriceps, have larger-than-normal knee adduction moments, which tend to load the medial tibiofemoral joint. Larger knee adduction moments predict progression of knee osteoarthritis and may contribute to the increased risk in meniscectomy patients. Increased muscle activity to support these large moments may further elevate articular loads. We examined a) the muscle activity while walking in a meniscectomy and control population, and b) the relationship between knee strength and muscle activity. Methods: Gait patterns and knee extension strength were assessed in 89 male arthroscopic partial meniscectomy patients and 30 age-matched healthy controls. Surface electromyography was recorded during walking from ten muscles that cross the knee. Findings: Compared to controls, the meniscectomy group displayed greater muscle activity while walking, with increased hamstrings activation, yet no difference in directed co-contraction. While controlling for age, no differences were found between meniscectomy subjects with weak and normal knee extension strength, in hamstrings activity, quadriceps activity or directed co-contraction. Interpretation: The generalised increase in non-directed muscle activity in the meniscectomy group may provide enhanced muscular support of larger-than-normal knee adduction moments. Higher levels of antagonist co-contraction may increase muscle forces and, subsequently, joint articular loads, contributing to the increased risk of developing knee osteoarthritis following arthroscopic partial meniscectomy. [Copyright &y& Elsevier]

Abstract: Background: Osteoarthritis is a common musculo-skeletal problem accompanied with muscle weakness. Muscle weakness may be readily improved by resistance training. Greater muscle strength has been associated with a lower knee joint loading rate. Methods: We conducted a single-blind randomized controlled trial of 54 female patients with osteoarthritis in at least one knee, according to the American College of Rheumatology clinical criteria. Patients were randomized into a 6-month high intensity progressive resistance training or a sham-exercise program. The primary outcomes were first peak knee and hip adduction moment measured using three-dimensional gait analysis at self-selected habitual and maximal speeds. Secondary outcomes were sagittal plane knee and hip moments, peak muscle strength, gait speed, and self-reported knee osteoarthritis symptoms measured by the Western Ontario and McMaster Osteoarthritis Index (WOMAC). Findings: Six months of high intensity resistance training did not change the first peak knee or hip adduction moment at either habitual or maximum walking speeds (P >0.413) compared to the sham-exercise. However, the second peak hip adduction moment (P =0.025) and WOMAC pain score (P <0.001) were reduced significantly in both groups over time, but there was no group effect. The changes in the second peak hip adduction moment were inversely related to the changes in the WOMAC pain score (r =−0.394, P =0.009). Interpretations: Muscle strength training in women with osteoarthritis, while effective for reducing osteoarthritis symptoms, appeared to operate through mechanisms other than improved knee or hip joint loading, as paradoxically, improved symptoms were related to decreases of hip adduction moment in late stance. [Copyright &y& Elsevier]

Background: Trunk lean over the stance limb during gait has been linked to a reduction in the knee adduction moment, which is associated with joint loading. We examined differences in knee adduction moments and frontal plane trunk lean during gait between subjects with knee osteoarthritis and a control group of healthy adults. Methods: Gait analysis was performed on 80 subjects (40 osteoarthritis). To define lateral trunk lean two definitions were used. The line connecting the midpoint between two reference points on the pelvis and the midpoint between the acromion processes was projected onto the lab frontal plane and the pelvis frontal plane. Pelvic tilt was also measured in the frontal plane as the angle between the pelvic and lab coordinate systems. Angles were calculated across the stance phase of gait. We analyzed the data, (i) by extracting discrete parameters (mean and peak) waveform values, and (ii) using principal component analysis to extract shape and magnitude differences between the waveforms. Findings: Osteoarthritis subjects had a higher knee adduction moment than the control group (α =0.05). Although the discrete parameters for trunk lean did not show differences between groups, principal component analysis did detect characteristic waveform differences between the control and osteoarthritis groups. Interpretation: A thorough biomechanical analysis revealed small differences in the pattern of motion of the pelvis and the trunk between subjects with knee osteoarthritis and control subjects; however these differences were only detectable using principal component analysis. [Copyright &y& Elsevier]

Background: Matrix-induced autologous chondrocyte implantation is a technique for repairing articular cartilage defects in the knee. Despite reported improvements in pain, little is known about the recovery of knee biomechanics during walking gait. Methods: A randomized controlled study design was used to investigate knee biomechanics during gait in 61 patients following matrix-induced autologous chondrocyte implantation, in conjunction with either ‘accelerated’ or ‘traditional’ approaches to post-operative weight-bearing rehabilitation. Gait analysis was performed at 3, 6 and 12months post-surgery in both patient groups, and two matched, unaffected control groups for comparison. Findings: The spatiotemporal and ground reaction force parameters were similar between patient groups and their respective control groups at all time points. When compared with controls, both patient groups demonstrated significantly reduced knee extension moments up until, and including, 12months. The traditional group demonstrated a significantly reduced knee adduction moment at 3, 6 and 12months, and a significantly reduced knee flexion moment at 3months. There were no differences in these knee moments between the accelerated patient group and controls. Interpretation: Overall, a higher level of gait dysfunction was observed in patients who underwent traditional rehabilitation. Future research is needed to investigate the recovery of normal gait following matrix-induced autologous chondrocyte implantation, and its effect on repair tissue development. [Copyright &y& Elsevier]

Background: An increase in the knee adduction moment is one of the risk factors of medial knee osteoarthritis. This study examined the relationship between knee adduction moment and self-reported pain and disability. We also investigated the influence of pain on the relationships between knee adduction moment and gait performance and disability. Methods: Thirty-eight Japanese women with medial knee osteoarthritis participated in this study (66.37years (41–79years)). Gait analysis involved the measurement of the external knee adduction moment impulse in the stance duration and during 3 subdivisions of stance. The total, pain and stiffness, and physical function Japanese Knee Osteoarthritis Measure scores were determined. Findings: The pain and stiffness, physical function, and total scores were positively correlated with the knee adduction moment impulses in the stance duration, and initial and second double support interval, and single limb support interval. The knee adduction moment impulse during the stance duration was related to the pain and stiffness subscale and gait velocity. The pain and stiffness subscale was related to the physical function subscale. Interpretation: Our results suggest that increasing in the knee adduction moment impulse, a proxy for loading on the medial compartment of the knee, is related to increased pain during weight-bearing activities such as walking, thereby restricting walking performance and causing disability by reducing gait velocity. Thus, the reduction in the knee adduction moment impulse during gait may result in pain relief and may serve as a conservative treatment option with disease-modifying potential. [Copyright &y& Elsevier]

Background: People with tetraplegia often have extensive paralysis of the hand yet retain crude hand function. Their hand function is dependent on manipulating wrist position with the neurally-intact wrist extensor muscles to change the passive tension in paralysed thumb muscles. This moves the thumb in relation to the paralysed index finger enabling basic grasp. The aim of this study was to quantify the effect of wrist position on thumb flexor and adductor torques generated in paralysed hands of people with tetraplegia. Methods: Thumb flexor and adductor torques were measured as the wrist was passively moved from a fully flexed to a fully extended position in 10 people with tetraplegia who had paralysis of all thumb muscles. The relationships between thumb torques and wrist angles were quantified with torque–angle curves. Findings: There was a consistent curvilinear relationship between wrist angle and both thumb flexor and thumb adductor torques. Thumb flexor torques were greatest and thumb adductor torques were smallest when the wrist was fully extended. Interpretation: Wrist position influences the thumb flexor and adductor torques generated in the paralysed hand. This is probably due to the effect of wrist position on the passive tension of the thumb muscles spanning the wrist. These findings have implications for people with C6 and C7 tetraplegia who rely on the passive torques generated by the paralysed thumb muscles for hand function. [Copyright &y& Elsevier]

Abstract: Background: Individuals with medial knee osteoarthritis often present with varus knee alignment and ambulate with increased knee adduction moments. Understanding the factors that relate to the knee adduction moment in healthy individuals may provide insight into the development of this disease. Thus, this study aimed to examine the relationships of both static and dynamic lower extremity measures with the knee adduction moment. We hypothesized that the dynamic measures would be more closely related to this moment. Methods: Arch height index, hip abduction strength and two static measures of knee alignment were recorded for 37 young asymptomatic knees that varied from normal to varus-aligned. Overground gait analyses were also performed. Correlation coefficients were used to assess the relationships between the static and dynamic variables to the knee adduction moment. Hierarchical regression analyses were then conducted using the static measures, the dynamic measures, and the static and dynamic measures together. Results: Among the static measures, the tibial mechanical axis and the distance between the medial knee joint lines were correlated with the knee adduction moment. The best predictive static model (R 2 =0.53) included only the tibial mechanical axis. Among the dynamic variables, knee adduction and rearfoot eversion angles were correlated with the knee adduction moment. Knee adduction and rearfoot eversion, together, were the best dynamic model (R 2 =0.53). The static and dynamic measures together created the strongest of the three models (R 2 =0.59). Conclusions: These results suggest that dynamic measures slightly enhance the predictive strength of static measures when explaining variation in the knee adduction moment. [Copyright &y& Elsevier]

Abstract: Background: Compared to matched controls, knee osteoarthritis patients walk with altered, kinematics, kinetics and muscle activity. Studies of osteoarthritis patient gait have focused on individual measures, and findings from these studies differ due to differences in patient levels of disability and age. Therefore, aims of this study were to examine kinematic, kinetic and muscle co-contraction gait variables within a single osteoarthritis patient group, and to determine if alterations in these variables are related to pain, symptom and function measures. Methods: Thirty asymptomatic controls and 54 patients with radiographic evidence of knee osteoarthritis participated. Self-perceived measures of pain and symptoms, and gait (knee joint angles, moments and muscle co-contraction) were analysed and compared. Findings: Osteoarthritis patients had greater self-perceived pain and symptoms on the questionnaires. Gait differences in the knee osteoarthritis patients were greater knee flexion at heel strike and during early stance along with reductions in the peak external knee extension moment in late stance. Co-contraction ratios highlighted greater lateral muscle activation in osteoarthritis patients, which were correlated with the magnitude of their adduction moments. Larger adduction moments were related to lower self-perceived pain and symptoms. Interpretation: Osteoarthritis patients use predominantly lateral muscle activation during stance which may aid in stabilising the external knee adduction moment. Kinematic alterations in knee osteoarthritis patient gait occur without alterations in knee joint moments. Our results also suggest that adduction moments are lowered to reduce the patients’ pain and symptoms. [Copyright &y& Elsevier]