Pelvic obliquity and rotation influences foot position estimates during running and sidestepping: "It's all in the hips"

Pelvic obliquity angles were hypothesised to influence mediolateral (ML) foot position estimates during sporting manoeuvres. Pelvic angles and ML foot position estimates during the weight acceptance phase of sidestepping and straight-line running tasks were obtained from 31 amateur Australian Rules Football players using three different kinematic models. ML foot position was calculated: 1) in the global reference frame, 2) in the pelvis reference frame and 3) in the pelvis reference frame following correction for changes in pelvic obliquity. Significant differences in ML foot position were observed between all three models in both task conditions (p < 0.05). Correcting for changes in time varying pelvic obliquity during running and sidestepping tasks is an important modelling consideration for the reliable measurement of ML foot position when investigating injury and/or stability.