Relationship between anthropometric and kinematic measures to practice velocity in elite American 100m sprinters

Abstract

There exists a paucity of anthropometric and kinematic data for elite United States (US) sprinters and further analysis of how these variables correlate with sprint velocity in practice is warranted.The purpose of this investigation was to examine the relationship of anthropometric and kinematic variables and practice sprint velocity of elite sprint athletes when separated by gender.Participants included elite US 100 m sprinters (total: n=38, male: n=19, female: n=19). Inclusion criteria were participation in the 100 m semifinals or finals at the US Outdoor National Championships from 2015 to 2019. Anthropometric data and 300 Hz video during maximum velocity sprinting were collected during a practice session and video was digitized to determine the kinematic variables of interest. Relationships with maximal sprint velocity were assessed using Pearson's correlation coefficient and linear regression analysis.Males showed significant unadjusted relationships between practice velocity and step length (r=0.668; P=0.002), horizontal backward foot velocity at touchdown (r=0.459; P=0.048), and upper leg full extension angle (r=-0.585; P=0.009). Multiple regression analysis found that when adjusting for these three variables, step length was the only significant predictor of practice velocity in males which accounted for 44.6% of the variability in practice velocity in males. The females showed a significant relationship between practice velocity and step length (r=0.629; P=0.004) which accounted for 39.5% of the variability in practice velocity.These results provide researchers and coaches with important information regarding the anthropometric and kinematic variables related to elite top speed sprinting performance.Training focused on increasing step length may be an efficient way to improve velocity in practice.