Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle-activation patterns during a squat

Authors

Elisabeth Macrum, University of Richmond
David Robert Bell, University of Wisconsin-Madison
Michelle Boling, University of North FloridaFollow
Michael Lewek, The University of North Carolina at Chapel Hill
Darin Padua, The University of North Carolina at Chapel Hill

Document Type

Article

Publication Date

1-1-2012

Abstract

Context: Limitations in gastrocnemius/soleus flexibility that restrict ankle dorsiflexion during dynamic tasks have been reported in individuals with patellofemoral pain (PFP) and are theorized to play a role in its development. Objective: To determine the effect of restricted ankle-dorsiflexion range of motion (ROM) on lower extremity kinematics and muscle activity (EMG) during a squat. The authors hypothesized that restricted ankle-dorsiflexion ROM would alter knee kinematics and lower extremity EMG during a squat. Design: Cross-sectional. Participants: 30 healthy, recreationally active individuals without a history of lower extremity injury. Interventions: Each participant performed 7 trials of a double-leg squat under 2 conditions: a nowedge condition (NW) with the foot flat on the floor and a wedge condition (W) with a 12° forefoot angle to simulate reduced plantar-flexor flexibility. Main Outcome Measures: 3-dimensional hip and knee kinematics, medial knee displacement (MKD), and ankle-dorsiflexion angle. EMG of vastus medialis oblique (VMO), vastus lateralis (VL), lateral gastrocnemius (LG), and soleus (SOL). One-way repeated-measures ANOVAs were performed to determine differences between the W and NW conditions. Results: Compared with the NW condition, the wedge produced decreased peak knee flexion (P .05). Conclusions: Altering ankle-dorsiflexion starting position during a double-leg squat resulted in increased knee valgus and MKD, as well as decreased quadriceps activation and increased soleus activation. These changes are similar to those seen in people with PFP. © 2012 Human Kinetics, Inc.

Publication Title

Journal of Sport Rehabilitation

Volume

21

Issue

2

First Page

144

Last Page

150

Digital Object Identifier (DOI)

10.1123/jsr.21.2.144

PubMed ID

22100617

ISSN

10566716

E-ISSN

15433072

Citation Information

Macrum, Bell, D. R., Boling, M., Lewek, M., & Padua, D. (2012). Effect of limiting ankle-dorsiflexion range of motion on lower extremity kinematics and muscle-activation patterns during a squat. Journal of Sport Rehabilitation, 21(2), 144–150. https://doi.org/10.1123/jsr.21.2.144