Hip External Rotator Strength Is Associated With Better Dynamic Control of the Lower Extremity During Landing TasksMalloy, Philip J.; Morgan, Alexander M.; Meinerz, Carolyn M.; Geiser, Christopher F.; Kipp, KristofJournal of Strength & Conditioning Research: January 2016 - Volume 30 - Issue 1 - p 282–291 doi: 10.1519/JSC.0000000000001069 Original Research Abstract Author Information Abstract: Malloy, PJ, Morgan, AM, Meinerz, CM, Geiser, CF, and Kipp, K. Hip external rotator strength is associated with better dynamic control of the lower extremity during landing tasks. J Strength Cond Res 30(1): 282–291, 2016—The purpose of this study was to determine the association between hip strength and lower extremity kinematics and kinetics during unanticipated single-leg landing and cutting tasks in collegiate female soccer players. Twenty-three National Collegiate Athletic Association division I female soccer players were recruited for strength testing and biomechanical analysis. Maximal isometric hip abduction and external rotation strength were measured using a hand-held dynamometer and expressed as muscle torque (force × femoral length) and normalized to body weight. Three-dimensional lower extremity kinematics and kinetics were assessed with motion analysis and force plates, and an inverse dynamics approach was used to calculate net internal joint moments that were normalized to body weight. Greater hip external rotator strength was significantly associated with greater peak hip external rotation moments (r = 0.47; p = 0.021), greater peak knee internal rotation moments (r = 0.41; p = 0.048), greater hip frontal plane excursion (r = 0.49; p = 0.017), and less knee transverse plane excursion (r = −0.56; p = 0.004) during unanticipated single-leg landing and cutting tasks. In addition, a statistical trend was detected between hip external rotator strength and peak hip frontal plane moments (r = 0.39; p = 0.06). The results suggest that females with greater hip external rotator strength demonstrate better dynamic control of the lower extremity during unanticipated single-leg landing and cutting tasks and provide further support for the link between hip strength and lower extremity landing mechanics. Program in Exercise Science, Department of Physical Therapy, Motion and Biomechanics Analysis Laboratory, Marquette University, Milwaukee, Winconsin Address correspondence to Philip Malloy, firstname.lastname@example.org. Copyright © 2016 by the National Strength & Conditioning Association.