The relationship between multi-joint eccentric strength and change of direction performance : A cross-sectional study on female soccer players

Abstract: Aim: The purpose of this study was to investigate the relationship between a multi-joint eccentric strength test with both change of direction performance and ground reaction force (GRF) of the penultimate foot contact (PFC) in female soccer players. This study also aimed to investigate the bilateral strength and performance differences between the dominant and non-dominant limb. Method: 21 female soccer players volunteered to participate in this study. All participants were free from injury and were currently playing in the 3rd highest league in Sweden. All tests for each participant took place during one visit at the Swedish School of Sport and Health Sciences. Strength measurements were performed on an isokinetic dynamometer that was converted into a motor driven leg press machine. Each participant performed three eccentric contractions at three different speeds (400, 800 and 1200 m/s) with each leg in the dynamometer. To determine change of direction performance, each participant executed three repetitions on each side in a change of direction test. During the change of direction test, force plates collected GRF data from the PFC. Results: Peak propulsive force had a large negative correlation with both eccentric impulse at 400 mm/s (r = - 0,552, p= 0,009) and eccentric impulse at 1200 mm/s (r = - 0,552, p= 0,007) for the right limb. A significant difference in eccentric peak force (p= 0,036) was found between the dominant and non-dominant limb. No significant correlation could be found between eccentric strength at any of the three speed levels and change of direction performance. No correlation could be found between the different GRF components and change of direction performance. Conclusion: Multi-joint eccentric strength did not significantly correlate with change of direction performance. Moreover, eccentric strength did not correlate with the GRF during a change of direction. Collectively, these findings are not in line with previous investigations.