Biomechanical effects following footstrike pattern modification using wearable sensors

Abstract

ObjectivesThis study sought to examine the biomechanical effects of an in-field sensor-based gait retraining program targeting footstrike pattern modification during level running, uphill running and downhill running. DesignQuasi-experimental design. MethodsSixteen habitual rearfoot strikers were recruited. All participants underwent a baseline evaluation on an instrumented treadmill at their preferred running speeds on three slope settings. Participants were then instructed to modify their footstrike pattern from rearfoot to non-rearfoot strike with real-time audio biofeedback in an 8-session in-field gait retraining program. A reassessment was conducted to evaluate the post-training biomechanical effects. Footstrike pattern, footstrike angle, vertical instantaneous loading rate (VILR), stride length, cadence, and knee flexion angle at initial contact were measured and compared. ResultsNo significant interaction was found between training and slope conditions for all tested variables. Significant main effects were observed for gait retraining (p-values≤0.02) and slopes (p-values≤0.01). After gait retraining, 75% of the participants modified their footstrike pattern during level running, but effects of footstrike pattern modification were inconsistent between slopes. During level running, participants exhibited a smaller footstrike angle (p≤0.01), reduced VILR (p≤0.01) and a larger knee flexion angle (p=0.01). Similar effects were found during uphill running, together with a shorter stride length (p=0.01) and an increased cadence (p≤0.01). However, during downhill running, no significant change in VILR was found (p=0.16), despite differences found in other biomechanical measurements (p-values=0.02–0.05). ConclusionAn 8-session in-field gait retraining program was effective in modifying footstrike pattern among runners, but discrepancies in VILR, stride length and cadence were found between slope conditions.