Relationship Between Anaerobic Sprint Test Performance And Dorsiflexion Range Of Motion In American Professional Soccer

PURPOSE: Within soccer, match and training analyses have revealed that players perform many low intensity aerobic activities, and several high intensity anaerobic activities, such as sprints. Further, high intensity running distance increases with the level of play. The Running Anaerobic Sprint Test (RAST) is a common test to evaluate anaerobic sprinting capacity. Previous research in elite youth soccer has suggested that functional measurements such as lower extremity range of motion may not predict performance well. Additionally, lower extremity stiffness may be associated with sprint speed. However, it is unknown how ankle range of motion influences anaerobic capacity in professional soccer players. Thus, the purpose of this study was to examine the relationship between dorsiflexion range of motion (DFROM) and RAST completion times. METHODS: Fifteen male United Soccer League (USL1) players completed the testing. The RAST was performed outdoors following the warmup phase of preseason practice. This test consisted of six max 35 m sprints with 10 seconds of passive recovery between each sprint. Completion time of the RAST was measured in seconds, with longer time indicating lesser anaerobic capacity. DFROM was obtained for both the dominant and nondominant limbs using the weight-bearing lunge test. Bivariate correlations were used to assess the relationship between RAST time and DFROM with an a priori alpha level of 0.05. RESULTS: Bivariate correlation results revealed a significant positive relationship between RAST time and the dominant limb DFROM (r = .67, p = .004), and the nondominant limb DFROM (r = .59, p = .014). These analyses suggest that higher amounts of DFROM were related to slower RAST times. CONCLUSIONS: The findings of the current study suggest that increased DFROM may be associated with slower RAST times. This would support previous studies on sprint mechanics that have shown increased ankle stiffness observed with increased velocity and efficiency in sprinting. Although it may appear more beneficial to have less DFROM in order to improve anaerobic capacity, reduced DFROM has also been linked to injury risk. Future research should examine how to optimize DFROM without negatively impacting RAST times and vice versa.