Abstract
Background: Anterior cruciate ligament (ACL) injuries have been studied using a variety of methods and tools. However, each is hindered by specific limitations with respect to its application. Aim: To assess the combined effects of external moments and muscle activations on ACL loading using serial, forward dynamics (FD) simulations of single leg, hyperextension landings in OpenSim. Methods: The FD tool of OpenSim was iteratively run using different combinations of knee-spanning muscle activation levels, internal rotation and valgus knee moment magnitudes. A regression was conducted on the data in order to predict ACL loading under different conditions. Results: A purely abduction moment leads to greater mean ACL loading than a purely internal rotation moment or any combination of the two. Additionally, the generalized boosted regression model using both external moments and certain knee muscles identified the internal rotation moment as the most important variable in predicting the ACL load (R2 = 0.9; p < 0.0001). Conclusion: This study demonstrated a novel and practical application of an OpenSim musculoskeletal model that supports the ACL injury mechanism of landing with low knee flexion angles, high muscle forces of the Quadriceps muscles and an external knee valgus moment, though further investigation is needed.
Highlights
Ruptures of the anterior cruciate ligament (ACL), one of the most serious injuries in sports, affect female athletes at an incidence rate 2.2 times higher than males [1]
About two thirds of Anterior cruciate ligament (ACL) injuries occur during a knee valgus or varus injury mechanism [3], and the mechanics of the landing and cutting maneuvers that may result in these injuries are thoroughly studied [4,5,6]
The combination of 0 N*m of internal rotation moment and 150 N*m of valgus moment resulted in the highest mean loading for both bundles (a: 667.0 ± 99.1 N, p: 1382.1 ± 168.5 N), while the combination of 90 N*m of rotation and 0 N*m of valgus resulted in the lowest mean loading for both bundles (a: 369.9 ± 65.9 N, p: 921.1 ± 118.1 N)
Summary
Ruptures of the anterior cruciate ligament (ACL), one of the most serious injuries in sports, affect female athletes at an incidence rate 2.2 times higher than males [1]. The multi-planar loading of the knee with abduction and internal rotation moments has been shown to result in higher ACL strains compared to that of uni-planar loading [8]. These findings have been used in motion capture studies to identify potential risk factors for ACL injury [5,6,9]. Aim: To assess the combined effects of external moments and muscle activations on ACL loading using serial, forward dynamics (FD) simulations of single leg, hyperextension landings in OpenSim. Methods: The FD tool of OpenSim was iteratively run using different combinations of knee-spanning muscle activation levels, internal rotation and valgus knee moment magnitudes. Conclusion: This study demonstrated a novel and practical application of an OpenSim musculoskeletal model that supports the ACL injury mechanism of landing with low knee flexion angles, high muscle forces of the Quadriceps muscles and an external knee valgus moment, though further investigation is needed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
