Two- and 3-dimensional knee valgus are reduced after an exercise intervention in young adults with demonstrable valgus during squatting

Abstract

Context: Two-dimensional (or medial knee displacement [MKD]) and 3-dimensional (3D) knee valgus are theorized to contribute to anterior cruciate ligament injuries. However, whether these displacements can be improved in the doublelegged squat (DLS) after an exercise intervention is unclear. Objective: To determine if MKD and 3D knee valgus are improved in a DLS after an exercise intervention. Design: Randomized controlled clinical trial. Setting: Research laboratory. Patients or Other Participants: A total of 32 participants were enrolled in this study and were randomly assigned to the control (n =16) or intervention (n = 16) group. During a DLS, all participants demonstrated knee valgus that was corrected with a heel lift. Intervention(s): The intervention group completed 10 sessions of directed exercise that focused on hip and ankle strength and flexibility over a 2- to 3-week period. Main Outcome Measure(s): We assessed MKD and 3D knee valgus during the DLS using an electromagnetic tracking system. Hip strength and ankle-dorsiflexion range of motion were measured. Change scores were calculated for MKD and 3D valgus at 0%, 10%, 20%, 30%, 40%, and 50% phases, and group (2 levels)-by phase (6 levels) repeated-measures analyses of variance were conducted. Independent t tests were used to compare change scores in other variables (α.05). Conclusions: The intervention reduced MKD and 3D knee valgus during a DLS. The intervention also increased ankle range of motion. Our inclusion criteria might have limited our ability to observe changes in hip strength. © by the National Athletic Trainers' Association, Inc.