Sacral accelerations predict whole body kinetics and stride kinematics during running

We developed models to predict peak vertical ground reaction force (vGRF), vertical impulse, and contact time (tc) from running speed and a waist-mounted accelerometer. 25 collegiate cross country athletes ran at 3.8-5.4 m/s while we measured vGRF and sacral accelerations. We low-pass filtered acceleration data with a 5Hz or 10Hz cut-off and compared each models’ predictive capability. Using a 5Hz cut-off better predicted vertical impulse and tc, while a 10Hz cut-off better predicted peak vGRF when the models were used on 4 new athletes. These models predicted peak vGRF, vertical impulse, and tc with 2-4% mean absolute error.