There is strong evidence linking an athlete's movement technique during sidestepping with anterior cruciate ligament (ACL) injury risk. However, it is unclear how these injurious postures are influenced by prior movement. We aim to describe preparatory trunk and thigh kinematics at toe‐off of the penultimate‐step and flight‐phase angular momenta, and explore their associations with frontal‐plane risk factors during unplanned sidestepping maneuvers. We analyzed kinematic and kinetic data of 33 male Australian Football players performing unplanned sidestepping tasks (103 trials). Linear mixed models tested for reliable associations between ACL injury risk during weight acceptance of the execution‐step, with preparatory kinematics and angular momenta of the trunk and thigh during the penultimate‐step. Multi‐planar flight‐phase trunk momenta along with hip abduction angle at penultimate‐step toe‐off were significantly associated with peak knee valgus moments during the execution‐step (R2 = .21, P < .01). Execution‐step trunk lateral flexion was significantly predicted by frontal and sagittal‐plane preparatory trunk positioning at toe‐off of the penultimate‐step (R2 = .44, P < .01). Multi‐planar flight‐phase trunk momenta as well as multi‐planar trunk and hip positioning at penultimate‐step toe‐off were associated with hip abduction during the execution‐step (R2 = .53, P < .01). Preparatory positioning of the trunk and hip, along with flight‐phase trunk momentum adjusting this positioning are linked to known ACL injury risk factors. We recommend that during the penultimate‐step athletes maintain an upright trunk, as well as minimize frontal‐plane trunk momentum and transverse‐plane trunk momentum toward the sidestep direction to reduce risk of ACL injury during unplanned sidesteps.

Frontal plane postures during the ultimate step of sidestepping are linked to increased anterior cruciate ligament injury risk. However, there is a lack of research detailing the kinematic strategies present in the penultimate step. This study, therefore, investigated penultimate and ultimate step kinematics of planned sidestepping (pSS) and unplanned sidestepping (upSS) to further understand the effect of planning time on known ultimate step kinematic and kinetic differences.Sixty male amateur Australian Rules football players performed three trials of straight-line running (RUN), pSS, and upSS in a randomized order. Mediolateral foot placement and three-dimensional joint kinematics for the knee, pelvis, and trunk were measured at final foot contact of the penultimate step and initial foot contact of the ultimate step. Peak knee moments were measured during the weight acceptance phase of the ultimate step. In pSS, at the penultimate step final foot contact, the support foot was placed across the midline of the center of mass, in the frontal plane, contralateral to the sidestep direction. Greater trunk lateral flexion toward the sidestep direction and greater negative pelvic lateral tilt were observed in pSS compared with upSS and RUN. Differences between pSS and upSS frontal plane kinematics at penultimate step final foot contact suggest preparatory reorientation strategies are likely constrained by the amount of planning time available. As there are clear differences in preparatory kinematics, we recommend that planning time be considered when training and assessing sidestepping maneuvers and planned and unplanned maneuvers not be treated as interchangeable skills.

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The aim of this study was to determine the effect of delivery stride length on the performance outcomes of ball release speed, accuracy and ball release height within a large cohort of elite male cricket fast bowlers. Data for this observational, cross-sectional study were collected from national under 19, senior state and international level players over a four-year period. No statistically significant differences were found between the three stride length groups (short, medium and long). However, a functional difference in accuracy was evident between short and long stride length groups, with the long stride length group being less accurate (effect size (ES) ¼ 0.8; ES confidence interval (CI) ¼ 0.2-1.4). Therefore, it can be concluded, given the results of the current study and previous injury-related research, that in no way is it advantageous for bowlers to have a stride length that exceeds the recommended 75-85% of standing height.