Carryover effects of treadmill-based footstrike modification gait retraining on overground running biomechanics

Gait retraining has gained attention as a practical intervention to improve running biomechanics and reduce injury risk. This study investigated the carryover effects of treadmill-based gait retraining on footstrike pattern, cadence, and vertical loading rate during overground running. Twelve recreational runners who habitually adopted a rearfoot strike (RFS) pattern participated in an eight-session treadmill-based gait retraining programme aimed at footstrike transition to a midfoot strike (MFS). The programme utilised real-time visual feedback and progressively reduced guidance to encourage sustainable biomechanical adaptations. Biomechanical assessments were conducted on both treadmill and overground surfaces before and after training. Results demonstrated significant reductions in footstrike angle (FSA) (95%CI interval -13.9 to -5.1; Cohen's d = 2.22), vertical loading rate (95%CI -0.49 to -41.56; Cohen's d = 0.76), and increased cadence (95%CI 2.47 to 14.06; Cohen's d = 0.87) during treadmill running. However, only the reduction in FSA transferred to overground running, with only 33% of participants exhibiting an MFS pattern during overground running after training, suggesting limited carryover of other biomechanical changes and highlighting discrepancies between trained and untrained conditions. These findings underscore the potential of gait retraining to modify running biomechanics while emphasising the need for overground-specific protocols to ensure effective transfer of improvements to real-world running environments.