Influence of chronological age on reactive strength in 8-13-year-old female figure skaters

Abstract

The purpose of this study was to determine the influence of chronological age on changes in the reactive strength index as an indicator of the ability to shorten the stretch cycle in female figure skaters of young age. We hypothesized that throughout the age period 8–13 years, female athletes experience a gradual improvement in the reactive strength of the lower extremities. The reactive strength index, which is a sports performance indicator and an injury risk indicator, was determined in six age groups of female figure skaters aged 8 to 13 years (n = 350). The results of the Welch ANOVA test showed a significant effect of age on the reactive strength index (F = 14.245, p < 0.001). The post hoc Dunnett test revealed significantly higher values in 11-, 12-and 13-year-old participants compared to 8 and 9-year-olds and in 13-year-olds compared to 10-year-olds. Age was also significant for jump height (F = 37.083, p < 0.001) but not for contact time (F = 1.458, p =.207). The observed increase in the reactive strength index throughout ages 8-13 reinforces the improvement in reactive strength consistent with a few studies in nonathletes and supports the suggestion that the application of the training stimuli that drive the development of the stretch-shortening cycle should begin in early youth. The data also indicate that the improvement in reactive strength was related to the increase in force during the concentric phase, rather than to the shortening of the eccentric and amortisation phases of the stretch-shortening cycle.