Are peak ground reaction forces related to better sprint acceleration performance?

This study aimed to elucidate whether the peak (maximum) ground reaction force (GRF) can be used as an indicator of better sprint acceleration performance. Eighteen male sprinters performed 60-m maximal effort sprints, during which GRF for a 50-m distance was collected using a long force platform system. Then, step-to-step relationships of running acceleration with mean and peak GRFs were examined. In the anteroposterior direction, while the mean propulsive force was correlated with acceleration during the initial acceleration phase (to the 5th step) (r = 0.559-0.713), peak propulsive force was only correlated with acceleration at the 9th step (r = 0.481). Moreover, while the mean braking force was correlated with acceleration at the 20th and 22nd steps (r = 0.522 and 0.544, respectively), peak braking force was not correlated with acceleration at all steps. In the vertical direction, significant negative correlations of mean and peak vertical forces with acceleration were found at the same steps (16th, 20th and 22nd step). These results indicate that while the peak anteroposterior force cannot be an indicator of sprint acceleration performance, the peak vertical force is likely an indicator for achieving better acceleration during the later stage of maximal acceleration sprinting.