J Orthop Res. 2021 Jun 8. doi: 10.1002/jor.25117. Online ahead of print.
ABSTRACT
Previous research suggests more biomechanically demanding tasks (e.g., stair descent, hopping) magnify biomechanical asymmetries compared with walking after anterior cruciate ligament (ACL) reconstruction. However, it is unclear if modifying task-specific constraints, like walking speed also elicits greater biomechanical asymmetries in this population. We examined the effects of manipulating walking speed on ground reaction force (GRF) asymmetries in individuals with ACL reconstruction and uninjured controls. Thirty individuals with ACL reconstruction (Age= 20.6 ± 5.4 yr., body mass index [BMI]= 23.9 ± 3.3 kg/m2 ) and fifteen controls (Age= 23.1 ± 4.5 yr., BMI= 23.6 ± 2.7 kg/m2 ) were tested on an instrumented treadmill at three speeds (100%, 120%, and 80% self-selected speed). Bilateral vertical and posterior-anterior GRFs were recorded at each speed. GRF asymmetries were calculated by subtracting the uninjured from the injured limb at each percent of stance. Statistical parametric mapping was used to evaluate the effects of speed on GRF asymmetries across stance. We found vertical and posterior GRF asymmetries were exacerbated at faster speeds and reduced at slower speeds in ACL individuals but not controls (p < 0.05). No differences in anterior GRF asymmetries were observed between speeds in either group (p > 0.05). Our results suggest increasing walking speed magnifies GRF asymmetries in individuals with ACL reconstruction. This article is protected by copyright. All rights reserved.
PMID:34101887 | DOI:10.1002/jor.25117
