Effects of Coordination and Strength Training on the Lower Extremity Inter-Segmental Coordination of Instep Kicking

The purpose of this study was to determine the effects of coordination training and strength training on the lower extremity inter-segmental coordination during instep kicking for novices. Thirty-two male college students with no soccer-specific training experience participated and were randomly assigned to either a coordination training group, a strength training group, or a kicking training group. Both the coordination and strength training groups also performed the same kicking training as the kicking training group. Each participant executed exercise training three times a week for eight weeks. The instep kicking test was performed before and after the three training sessions. Two-way ANOVAs were conducted to determine the training effects on the kicking performance and the inter-segmental coordination. The maximum ball speed significantly increased for all three training groups (<i>p</i> < 0.001, effect size = 0.638). In contrast, improvements in kicking accuracy were specific to the coordination training group (<i>p</i> = 0.001, effect size = 0.326), with no significant changes observed in the strength (<i>p</i> = 0.052, effect size = 0.138) or kicking groups (<i>p</i> = 0.953, effect size < 0.001). The time spent percentage of the knee-ankle shank-phase coordination pattern in the leg-cocking phase was significantly increased (<i>p</i> = 0.003, effect size = 0.268), but the time spent percentage of the hip-knee thigh-phase in the back swing phase significantly decreased after the three trainings (<i>p</i> = 0.031, effect size = 0.150). A significant reduction in the relative activity of the tibialis anterior and gastrocnemius muscles occurred exclusively after coordination training (<i>p</i> = 0.024, effect size = 0.188). This study confirms that coordination training provides a unique contribution to skill acquisition in novices, specifically enhancing kicking accuracy and neuromuscular control, whereas improvements in maximal ball speed were generic to all training types.