The effect of using frontal shoe orthotics and plyometric training on selected functional measurements in junior high school football players

Abstract

Plyometric training incorporates quick powerful movements involving an active pre-stretching (eccentric muscle contraction) prior to concentric contraction. It has been claimed that the effect of plyometric training could be enhanced using a frontal shoe orthotic due to increased overload created by this appliance. However, no study to date has examined this claim. Therefore, the purpose of the present study was to determine whether the use of the Jumpsole, a frontal shoe orthotic, will enhance the effect of plyometric training on vertical jump, 40 yard dash time, and calf circumference. Thirty five healthy eighth and ninth grade males participating on the same junior high school football team volunteered to participate in this study. A stratified sampling technique was used to ensure similarity on a weight and position basis between a control group (18 males) and experimental group (17 males). The control group completed the 6-week training program without the Jumpsole shoe orthotic. The 6-week training program consisted of 45 min to 1 h sessions performed bi-weekly utilizing acceleration activity, skipping, lateral cone hops, bounding, jump rope, and depth (box) jumps. Vertical jump, 40 yard dash time, and calf circumference were measured before and after the 6 weeks of training. A two-way multivariate analysis of variance with repeated measures on one factor and appropriate follow-up repeated measures univariate analyses revealed that the only significant difference occurred between the pre-test and post-test (irrespective of influence of whether the subjects were in the experimental group or the control group) for the dependent variable vertical jump. These results indicate that, although the plyometric training program was effective for enhancing vertical jump, the training program did not improve speed of running or size of calf muscle. Additionally, the use of the frontal shoe orthotic in an attempt to enhance the plyometric training program was not effective.