BackgroundThe biomechanics of barefoot and shod running are different for typically developing children but unknown for children with cerebral palsy (CP). Such differences may have implications for injury and performance.AimsThe primary aims of this study were to compare the lower limb biomechanics of barefoot and shod running in children with CP, and to determine whether any differences were the same in GMFCS levels I and II.MethodsThis cross-sectional study examined 38 children with CP (n = 24 (GMFCS) level I; n = 14 GMFCS II), running overground at 3 speeds (jog, run, sprint) in barefoot and shod conditions. Marker trajectories and force plate data were recorded, and lower limb kinematics, kinetics and spatiotemporal variables were derived. Differences between barefoot and shod running were analysed using linear mixed models.ResultsFor both GMFCS levels, barefoot running resulted in higher loading rates, but smaller impact peaks at all speeds. Barefoot running was associated with greater hip and knee power; less ankle dorsiflexion and hip flexion at initial contact, and less ankle and knee range of motion during stance, compared to shod running, at all speeds. Barefoot stride length was shortened, and cadence increased compared to shod during jogging and running but not sprinting. For GMFCS level I only, barefoot running involved a higher incidence of forefoot strike, greater ankle power generation and less hip range of motion during stance.SignificanceRunning barefoot may facilitate running performance by increasing power generation at the ankle in children with CP, GMFCS level I. Higher barefoot loading rates may have implications for performance and injury.

Background: Previous studies using self-reported physical activity (PA) have shown relationships between psychological constructs of enjoyment and perceived competence, however limited studies have done so using objective measures of PA to confirm these relationships. The purpose of this study was to investigate the relationship between enjoyment, perceived competence and sprint performance with PA levels measured subjectively and objectively.

Introduction: Unstructured physical activity, playground games and the sports that Australian boys participate are dominated by short sprints. With a high association between motor skill competency and higher levels of physical activity, an understanding of factors contributing to spring performance could be advantageous. Research in adults has shown lower limb concentric power and stiffness to correlate to sprint performance, with inconsistent findings regarding the influence of rate of force development (RFD) and peak force (PF) on sprinting. Predictors of sprint performance in pre-adolescent boys is lacking, therefore this study investigated the relationship between lower limb concentric power, lower limb stiffness, RFD, PF and sprint performance in boys.

Taping is often used to manage the high rate of knee injuries in ballet dancers; however, little is known about the effect of taping on lower-limb biomechanics during ballet landings in the turnout position. This study investigated the effects of Kinesiotape (KT), Mulligan's tape (MT) and no tape (NT) on knee and hip kinetics during landing in three turnout positions. The effect of taping on the esthetic execution of ballet jumps was also assessed. Eighteen pain-free 12-15-year-old female ballet dancers performed ballet jumps in three turnout positions, under the three knee taping conditions. A Vicon Motion Analysis system (Vicon Oxford, Oxford, UK) and Advanced Mechanical Technology, Inc. (Watertown, Massa chusetts, USA) force plate collected lower-limb mechanics. The results demonstrated that MT significantly reduced peak posterior knee shear forces (P = 0.025) and peak posterior (P = 0.005), medial (P = 0.022) and lateral (P = 0.014) hip shear forces compared with NT when landing in first position. KT had no effect on knee or hip forces. No significant differences existed between taping conditions in all landing positions for the esthetic measures. MT was able to reduce knee and the hip forces without affecting the esthetic performance of ballet jumps, which may have implications for preventing and managing knee injuries in ballet dancers.

Background: During the 2012 Olympic Games field hockey tournament, the penalty corner drag flick was the most prevalent scoring method. The drag flick is a difficult skill to master requiring a combination of coordination, strength and timing. Consequently, only a select few players acquire sufficient skill to perform a successful drag flick. The multiple repetitions and hours of training required of specialist drag flickers predisposes them to an increased risk of overuse injuries. Anecdotally, drag flickers have a higher prevalence of injury; however, this is yet to be confirmed by a large-scale retrospective analysis comparing injury prevalence between drag flickers and non-drag flickers.

The purpose of this study was to compare the effects of Mulligan's tape (MT) and kinesio tape (KT) with no tape (NT) on hip and knee kinematics and kinetics during running. Twenty-nine female recreational runners performed a series of run-throughs' along a 10-m runway under the three taping conditions. Two force plates and a 14-camera Vicon motion analysis system (Oxford Metrics, Inc., Oxford, UK) captured kinematic and kinetic data for each dependent variable from ground contact to toe off. Comparisons of each dependent variable under three taping conditions were assessed through Statistical Package for the Social Sciences (SPSS; SPSS, Inc., Chicago, Illinois, USA; P-value<0.01) using repeated measure analyses of variance. For each dependent variable with a P-value<0.01, repeated measures with pairwise comparisons and Bonferroni adjustment were conducted to compare the three taping conditions. MT induced a significant reduction in anterior and posterior hip forces, knee flexion angular velocity, knee extensor moments, and hip flexion and extension moments compared with NT and KT (P=0.001). There was no difference in hip or knee, kinematics or kinetics, between KT and NT (P=1.000). MT appears to influence hip and knee biomechanics during running in an asymptomatic sample, whereas KT appeared to be biomechanically not different from NT.