Research has often examined the relationship between one or two measures of strength and change of direction (COD) ability reporting inconsistent relationships to performance. These inconsistences may be the result of the strength assessment utilized and the assumption that one measure of strength can represent all "types" of strength required during a COD task. Therefore the purpose of this study was to determine the relationship between several lower body strength and power measures, COD and agility performance. Twelve (n=12) elite female basketball athletes completed a maximal dynamic back squat, isometric mid-thigh pull, eccentric and concentric only back squat, and a counter-movement jump, followed by two COD tests (505 and T-Test) and a reactive agility test. Pearson product moment correlation and stepwise regression analysis were performed on all variables. The percentage contribution of each strength measure to an athletes total strength score was also determined. Our results demonstrated that both COD tests were significantly correlated to maximal dynamic, isometric, concentric and eccentric strength (r = -0.79 to -0.89), with eccentric strength identified as the sole predictor of COD performance. Agility performance did not correlate with any measure of strength (r = -0.08 to -0.36), while lower body power demonstrated no correlation to either agility or COD performance (r = -0.19 to -0.46). These findings demonstrate the importance of multiple strength components for COD ability, highlighting eccentric strength as a deterministic factor of COD performance. Coaches should aim to develop a well-rounded strength base in athletes; ensuring eccentric strength is developed as effectively as the often-emphasized concentric or overall dynamic strength capacity.
Copyright (C) 2014 by the National Strength & Conditioning Association.