There appears to be no clear overall mechanical advantage of a habitual FFS or RFS. Switching techniques may have different injury implications given the altered distribution in loading between joints but should be weighed against the overall effects on limb mechanics; adopting an imposed RFS may prove the most beneficial given the absence of any clear mechanical performance decrements.

The kinematic mechanisms associated with elevated externally applied valgus knee moments during non-contact sidestepping and subsequent anterior cruciate ligament (ACL) injury risk are not well understood. To address this issue, the residual reduction algorithm (RRA) in OpenSim was used to create nine subject-specific, full-body (37 degrees of freedom) torque-driven simulations of athletic males performing unplanned sidestep (UnSS) sport tasks. The RRA was used again to produce an optimized kinematic solution with reduced peak valgus knee torques during the weight acceptance phase of stance. Pre-to-post kinematic optimization, mean peak valgus knee moments were significantly reduced by 44.2 Nm (p=0.045). Nine of a possible 37 upper and lower body kinematic changes in all three planes of motion were consistently used during the RRA to decrease peak valgus knee moments. The generalized kinematic strategy used by all nine simulations to reduce peak valgus knee moments and subsequent ACL injury risk during UnSS was to redirect the whole-body center of mass medially, towards the desired direction of travel.

Purpose Determine if balance and technique training (BTT) implemented adjunct to normal Australian football (AF) training reduces external knee loading during sidestepping. Additionally, the authors determined if an athlete's knee joint kinematics and kinetics change over a season of AF. Methodology Eight amateur-level AF clubs (n=1,001 males) volunteered to participate in either 28 weeks of BTT or a 'sham' training (ST) adjunct to their normal preseason and regular training. A subset of 34 athletes (BTT, n=20; ST, n=14) were recruited for biomechanical testing in weeks 1-7 and 18-25 of the 28-week training intervention. During biomechanical testing, participants completed a series running, preplanned (PpSS) and unplanned sidestepping (UnSS) tasks. A linear mixed model (α=0.05) was used to determine if knee kinematics and peak moments during PpSS and UnSS were infl uenced by BTT and/or a season of AF.

This study aimed to develop a 2-dimensional (2D) video screening tool capable of predicting an athlete’s peak 3-dimensional (3D) knee moments during unplanned sidestepping. 2D video-based kinematic measures were simultaneously captured with 3D peak knee moments for 30 female field hockey players (15 junior, 15 senior). Intra- and intertester repeatability of 2D kinematic measures was performed. Then, linear regression models were used to model 3D knee moments from 2D kinematic variables utilizing 80% of the sample (n=24). Regression equations were then validated on the remaining 20% of the sample (n=6). Angular 2D measures had good-excellent intra- (ICC=0.936–0.998) and intertester (ICC=0.662–0.949) reliability. Displacement measures had poor-excellent intra- (ICC=0.377–0.539) and inter-tester (ICC=0.219–0.869) reliability. Significant independent predictors of peak knee moments were dynamic knee valgus, knee flexion angle at foot strike, trunk flexion range of motion (ROM), trunk lateral flexion, hip abduction and knee flexion ROM (P<0.05). Regression equations generated from these models effectively predicted peak knee extension, valgus and internal rotation moments (i. e., were not different from measured values P>0.05, ES<0.4) in the 20% subsample. 2D video-based measurements of an athlete's full body kinematics during unplanned sidestepping provide a reliable, specific, sensitive and cost-effective means for screening female team sport athletes.

Aim To determine if neuromuscular electrical stimulation (NMES) applied to the ankle dorsiflexors during gait improves muscle volume and strength in children with unilateral spastic cerebral palsy (CP). Method Thirty‐two children (15 females, 17 males; mean age 10y 8mo, age range 5y 5mo–18y 1mo) with unilateral spastic CP and a Gross Motor Function Classification System of level I or level II were randomly assigned to either the 8‐week daily NMES treatment group or control group (usual or conventional treatments). Outcomes at week 8 (post‐NMES) and week 14 (carryover) included magnetic resonance imaging for muscle volumes (tibialis anterior, anterior compartment, and gastrocnemius), strength (hand‐held dynamometry for isometric dorsiflexion strength and heel raises for functional strength), and clinical measures for lower limb selective motor control. Results At week 8, the treatment group demonstrated significantly (p<0.05) increased muscle volumes for tibialis anterior, anterior compartment, medial and lateral gastrocnemius, and dorsiflexion strength not only when compared to their baseline values but also when compared to the control group at week 8. At week 14, both tibialis anterior and lateral gastrocnemius volumes in the treatment group remained significantly increased when compared to their baseline values. However, only lateral gastrocnemius volumes had significantly greater values when compared to the control group at week 14. There were no between group differences in the clinical measures for lower limb selective motor control at week 8 and 14. Interpretation Eight weeks of daily NMES‐assisted gait increases muscle volume and strength of the stimulated ankle dorsiflexors in children with unilateral spastic CP. These changes are use‐dependent and do not carry over after the 8‐week treatment period. Gastrocnemius volume also increased post‐treatment with carryover at week 14.