Increased external hip-rotation strength relates to reduced dynamic knee control in females: paradox or adaptation?

Authors


Corresponding author: Thomas Bandholm, PhD, Clinical Research Centre(Section 136), Copenhagen University Hospital at Hvidovre, Kettegaard Allé 30, DK-2650, Hvidovre, Denmark. Tel: +45 3632 6344, E-mail: thomas.bandholm@hvh.regionh.dk

Abstract

The purpose of the present study was to examine the relationship between hip muscle strength (abduction and external rotation) and frontal-plane knee control during drop jumping in recreational female athletes. Thirty-three healthy young recreational female athletes were included. Maximal isometric hip abduction and external rotation torque were measured using hand-held dynamometry, and frontal-plane knee control during drop jumping was assessed using three-dimensional motion analysis. Frontal-plane knee control during drop jumping was expressed as the absolute (cm) and relative (cm/cm body height) change in distance between lateral knee markers from foot–ground contact to the time of minimal marker distance during the contact phase of the jump. Greater maximal external hip-rotation torque correlated significantly with greater absolute (r=0.48, P=0.005) and relative (r=0.43, P=0.012) change in knee marker distance during drop jumping. Maximal hip-abduction torque did not correlate with the absolute (r=0.18, P=0.31) or relative (r=0.19, P=0.29) change in knee marker distance during drop jumping. Contrary to our expectations, greater maximal external hip-rotation torque was related to greater change in knee marker distance during drop jumping (reduced frontal-plane knee control) in recreational female athletes.

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