The effect of a knee brace on muscle forces during single-leg landings at two heights

Abstract Background: The single-leg landing is one of the maneuvers that has been linked to non-contact ACL injuries, and knee braces have been shown to reduce ACL injury incidence. The purpose of this study was to determine whether a knee brace has an effect on muscle force during single-leg landings at two heights through musculoskeletal simulation.Methods: 11 healthy male participants were recruited to complete single-leg landings at 30 cm and 45 cm between the braced and non-braced. We recorded trajectories and ground reaction force using an 8-camera motion capture system and a force platform. The captured data was imported into the generic musculoskeletal model (Gait2392) in OpenSim. Static optimization was used to calculate muscle forces. Results: The gluteus minimus, rectus femoris, vastus medialis, vastus lateralis, vastus medialis medial gastrocnemius, lateral gartrocnemius, and soles muscle forces all showed statistically significant differences between the braced and non-braced. Simultaneously, increasing landing height significantly affected gluteus maximums, vastus medialis, and vastus intermedia muscle forces. Conclusions: Our findings imply that the knee brace may be able to alter muscle forces in single-leg landings to prevent anterior cruciate ligament injury. Additionally, research demonstrates that people should avoid landing from heights due to the increased risk of knee injuries.