INFLUENCE OF TRUNK STABILITY AND LEG STRENGTH TRAINING ON VERTICAL TAKE-OFF VELOCITY IN ATHLETES

Abstract

Our objective was to determine the influence of trunk stability training and leg strength training on the performance of vertical jumping as assessed by vertical take-off velocity. Athletes (20 males, 35 females) were randomly assigned to one of four training groups: trunk stability (TS), leg strength (LS), trunk stability and leg strength (TL), and control (CO). Subjects were tested at baseline; after three weeks of training; and at the end of a nine-week training period. A repeated measures ANCOVA was used to examine differences between groups for vertical take-off velocity as determined from a force plate, with baseline take-off velocity and initial body mass as covariates. After three weeks of training, only the TS group had a significantly greater vertical take-off velocity compared to the control group (p < 0.03). After nine weeks of training, however, all three training groups were statistically greater than the control group (p < 0.03) but not different from each other. We conclude that trunk stability and leg strength training are equally effective for later (nine weeks) improvement in vertical jumping ability. Trunk stability training appears to be most effective for early (three weeks) improvement in vertical jumping ability. This finding might imply that improvements in take-off velocity as a result of greater trunk stability might stem from neuro-muscular learning rather than from muscular physiological changes.