Asymmetries of kinematics and kinetics in female and male sprinting.

Abstract

This study examined asymmetries in spatiotemporal (e.g. step length and frequency) and kinetic variables during maximal speed sprinting and aimed to determine differences in the asymmetries between female and male sprinters, and to examine relationships between magnitudes of asymmetries and sprint performance. Thirty-two female and 32 male sprinters, who were of comparable performance levels, performed 60-m sprints. Spatiotemporal and ground reaction force variables during maximal speed phase were measured using a long force platform system. The asymmetry was calculated as a difference between values obtained from right and left sides divided by the mean of the two sides. The magnitudes of asymmetries in step length (4.60% vs. 3.08%), step frequency (4.70% vs. 3.11%), stance time (3.81% vs. 2.12%), vertical impulse (8.41% vs. 5.30%) and braking mean force (13.32% vs. 8.55%) for male sprinters were greater than those for female sprinters. No significant correlation was found between maximal running speed and magnitudes of asymmetries for female or male sprinters. The results demonstrate that the magnitudes of asymmetries in step length, step frequency, stance time, vertical impulse and braking mean force during sprinting could be greater in male sprinters. Moreover, no magnitude of asymmetries could be associated with sprint performance for female and male sprinters. Although it is likely beneficial to be aware that there are greater asymmetries in male sprinting during the maximal speed phase compared to female sprinting as a baseline, the magnitudes of asymmetries can be individually different regardless of performance level.