Comparison of Gait Symmetry and Joint Moments in Unilateral and Bilateral Hip Osteoarthritis Patients and Healthy Controls

Patients with unilateral hip osteoarthritis show a characteristic gait pattern in which they unload the affected leg and overload the unaffected leg. Information on the gait characteristics of patients with bilateral hip osteoarthritis is very limited. The main purposes of this study were to investigate whether the gait pattern of both legs of patients with bilateral hip osteoarthritis deviates from healthy controls and whether bilateral hip osteoarthritis patients show a more symmetrical joint load compared to unilateral hip osteoarthritis patients. In this prospective study, 26 patients with bilateral hip osteoarthritis, 26 patients with unilateral hip osteoarthritis and 26 healthy controls were included. The three groups were matched for gender, age and walking speed. Patients were scheduled for a unilateral total hip arthroplasty on the more affected/more painful side. All participants underwent a three-dimensional gait analysis. Gait kinematics and gait kinetics of patients and controls were compared using Statistical Parametric Mapping. Corrected for speed, the gait kinematics and kinetics of both legs of patients with bilateral hip osteoarthritis differed from healthy controls. Bilateral patients had symmetrical knee joint loading, in contrast to the asymmetrical knee joint loading in unilateral hip osteoarthritis patients. The ipsilateral leg of the bilateral patients could be included in studies in addition to unilateral hip osteoarthritis patients as no differences were found. Although patients with bilateral hip osteoarthritis show more symmetrical frontal plane knee joint moments, a pathological external knee adduction moment in the second half of stance was present in the ipsilateral leg in patients with unilateral and bilateral hip osteoarthritis. The lateral adjustment of the knee adduction moment may initiate or accelerate progression of degenerative changes in the lateral compartment of the knee.

EMG-informed neuromusculoskeletal models accurately predict knee loading measured using instrumented implants

<p>We investigated three different methods for simulating neuromusculoskeletal (NMS) control to generate estimates of knee joint loading which were compared to in-vivo measured loads. The major contributions of this work to the literature are in generalizing EMG-informed and probabilistic methods for modelling NMS control.</p> <p>A single calibration function for EMG-informed NMS modelling was identified which accurately estimated knee loads for multiple people across multiple trials. Using a stochastic approach to NMS modelling, we investigated the range of possible solutions for knee joint loading during walking, showing the method's generalizability and capability to generate solutions which encompassed the measured knee loads. Through this stochastic approach, we were able to show that a single degree of freedom planar knee is suited to estimating total knee loading, but is insufficient for estimating the directional components of load.</p> <p> </p>

EMG-informed neuromusculoskeletal models accurately predict knee loading measured using instrumented implants

<p>We investigated three different methods for simulating neuromusculoskeletal (NMS) control to generate estimates of knee joint loading which were compared to in-vivo measured loads. The major contributions of this work to the literature are in generalizing EMG-informed and probabilistic methods for modelling NMS control.</p> <p>A single calibration function for EMG-informed NMS modelling was identified which accurately estimated knee loads for multiple people across multiple trials. Using a stochastic approach to NMS modelling, we investigated the range of possible solutions for knee joint loading during walking, showing the method's generalizability and capability to generate solutions which encompassed the measured knee loads. Through this stochastic approach, we were able to show that a single degree of freedom planar knee is suited to estimating total knee loading, but is insufficient for estimating the directional components of load.</p> <p> </p>

A 2D qualitative movement assessment of a deceleration task detects football players with high knee joint loading

Purpose The deceleration (pressing) is a common situational pattern leading to anterior cruciate ligament (ACL) injury in football. Although mainly assessed for performance purposes, a stronger focus on movement quality might support the screening of at-risk athletes. The aim of the present study was to describe a 2D scoring system for the assessment of the deceleration task and to associate it with the knee joint loading (knee abduction moment) evaluated through the gold standard 3D motion capture. The hypothesis was that lower 2D scores would be associated with higher knee joint loading. Methods Thirty-four competitive football (soccer) players (age 22.8 ± 4.1, 16 females) performed a series of deceleration tasks. 3D motion analysis was recorded using ten stereophotogrammetric cameras, a force platform, and three high-speed cameras. The 2D qualitative assessment was performed via a scoring system based on the video analysis of frontal and lateral planes joint kinematics for five scoring criteria. The intra- and inter-rater reliabilities were calculated for each 2D scoring criteria. The peak knee abduction moment was extracted and grouped according to the results of the 2D evaluation. Results An ICC > 0.94 was found for all the 2D scoring criteria, both for intra-rater and inter-rater reliability. The players with low 2D frontal plane scores and low total scores (0–4) showed significantly higher peak knee abduction moment values (p < 0.001). A significant negative rank correlation was found between the total score and the peak knee abduction moment (ρ = − 0.25, p < 0.001). Conclusions The qualitative 2D scoring system described successfully discerned between athletes with high and low knee joint loading during a deceleration task. The application of this qualitative movement assessment based on a detailed and accurate scoring system is suitable to identify players and patients with high knee joint loading (high knee abduction moments) and target additional training in the scenario of the primary and secondary ACL injury risk reduction. Level of evidence Level IV.

Biomechanical Determinants of Performance and Injury Risk During Cutting: A Performance-Injury Conflict?

Background Most cutting biomechanical studies investigate performance and knee joint load determinants independently. This is surprising because cutting is an important action linked to performance and non-contact anterior cruciate ligament (ACL) injuries. The aim of this study was to investigate the relationship between cutting biomechanics and cutting performance (completion time, ground contact time [GCT], exit velocity) and surrogates of non-contact ACL injury risk (knee abduction [KAM] and internal rotation [KIRM] moments) during 90° cutting. Design Mixed, cross-sectional study following an associative design. 61 males from multidirectional sports performed six 90° pre-planned cutting trials, whereby lower-limb and trunk kinetics and kinematics were evaluated using three-dimensional (3D) motion and ground reaction force analysis over the penultimate (PFC) and final foot contact (FFC). Pearson’s and Spearman’s correlations were used to explore the relationships between biomechanical variables and cutting performance and injury risk variables. Stepwise regression analysis was also performed. Results Faster cutting performance was associated (p ≤ 0.05) with greater centre of mass (COM) velocities at key instances of the cut (r or ρ = 0.533–0.752), greater peak and mean propulsive forces (r or ρ = 0.449–0.651), shorter FFC GCTs (r or ρ = 0.569–0.581), greater FFC and PFC braking forces (r = 0.430–0.551), smaller hip and knee flexion range of motion (r or ρ = 0.406–0.670), greater knee flexion moments (KFMs) (r = 0.482), and greater internal foot progression angles (r = − 0.411). Stepwise multiple regression analysis revealed that exit velocity, peak resultant propulsive force, PFC mean horizontal braking force, and initial foot progression angle together could explain 64% (r = 0.801, adjusted 61.6%, p = 0.048) of the variation in completion time. Greater peak KAMs were associated with greater COM velocities at key instances of the cut (r or ρ = − 0.491 to − 0.551), greater peak knee abduction angles (KAA) (r = − 0.468), and greater FFC braking forces (r = 0.434–0.497). Incidentally, faster completion times were associated with greater peak KAMs (r = − 0.412) and KIRMs (r = 0.539). Stepwise multiple regression analysis revealed that FFC mean vertical braking force and peak KAA together could explain 43% (r = 0.652, adjusted 40.6%, p < 0.001) of the variation peak KAM. Conclusion Techniques and mechanics associated with faster cutting (i.e. faster COM velocities, greater FFC braking forces in short GCTs, greater KFMs, smaller hip and knee flexion, and greater internal foot progression angles) are in direct conflict with safer cutting mechanics (i.e. reduced knee joint loading, thus ACL injury risk), and support the “performance-injury conflict” concept during cutting. Practitioners should be conscious of this conflict when instructing cutting techniques to optimise performance while minimising knee joint loading, and should, therefore, ensure that their athletes have the physical capacity (i.e. neuromuscular control, co-contraction, and rapid force production) to tolerate and support the knee joint loading during cutting.

Functional stretching decreases knee joint loading in male athletes with gastroc--soleus tightness

Background and objective: Tightness of the gastroc--soleus muscle complex is one of the limiting factors of the ankle joint's range of motion (ROM) during daily activities. The aim of this study was to investigate the effectiveness of functional and extra-functional stretching of the gastrocnemius--soleus complex on knee joint loading in athletes with limited ankle dorsiflexion. Material and methods: In this cross-sectional study, 30 male athletes with gastrocnemius--soleus shortness were recruited and randomly divided into three equal-size groups of functional stretching, extra-functional stretching, and a control group. The extra-functional stretching group performed stretching exercises three times per day for eight weeks. The functional stretching group was instructed to change their gait pattern via increased heel strike during daily activities. Results: None of the stretching programs reduced the knee flexion angle in heel contact (p > 0.05). The knee flexion angle was significantly increased in the stance phase in the functional group (p ≤ 0.05). Walking speed was increased significantly in the extra-functional group (p ≤ 0.05). The knee adductor moment and external rotation moment decreased significantly in the functional group (p ≤ 0.05). Conclusion: An eight-week functional stretching program in this study led to a reduction of knee loading in the frontal and horizontal planes in comparison to the extra-functional stretching group, demonstrating the effectiveness of functional stretching in improving knee joint biomechanics during walking.