Assessing sprint technique with shoe-mounted inertial sensors

Negative foot speed (i.e., the speed of the backward and downward motion of the foot relative to the body at ground contact) is a strong predictor of sprinting performance. Inertial measurement units (IMUs) are becoming a popular approach for assessing sports performance. The primary aim of this study was to use IMUs to investigate the relationship between negative foot speed and top running speed attained during a sprint on an outdoor track. Seventeen participants performed 80-meter track sprints while wearing a shoe-mounted IMU. Anteroposterior and vertical components of negative foot speed were extracted from the IMU. For the mean peak stride speed of 7.98{+/-}0.78m/s, the adjusted R2 values were 0.27 and 0.42 versus the anteroposterior and vertical components of negative foot speed, respectively. In conclusion, our findings support the common coaching tip of increasing negative foot speed to improve sprint speed. In addition, the results of this study support the use of IMUs for quantifying sprinting technique with actionable metrics.