The association of ankle dorsiflexion range of motion with hip and knee kinematics during the lateral step-down test

Abstract

STUDY DESIGN: Controlled laboratory study. BACKGROUND: Altered hip and knee kinematics have been associated with several knee disorders, including anterior cruciate ligament tear, patellofemoral pain, and iliotibial band syndrome. Limited ankle dorsiflexion (DF) range of motion (ROM), which has been linked with some of these disorders, has also been associated with altered knee kinematics. OBJECTIVE: To explore the association of ankle DF ROM with hip and knee kinematics during a step-down task. METHODS: Thirty healthy participants underwent a 3-D analysis of hip and knee kinematics during a lateral step-down test, followed by measurement of ankle DF ROM in weight bearing (WB) and non-weight bearing (NWB). Participants were dichotomized using the median values into lowand high-DF subgroups within both WB and NWB. Hip and knee kinematics were compared between the low-and high-DF subgroups. RESULTS: Participants in the low-DF subgroups exhibited greater peak hip adduction (WB, P = .02; NWB, P