Prophylactic knee bracing alters lower-limb muscle forces during a double-leg drop landing.
Anterior cruciate ligament (ACL) injury can be a painful, debilitating and costly consequence of participating in sporting activities. Prophylactic knee bracing aims to reduce the number and severity of ACL injury, which commonly occurs during landing maneuvers and is more prevalent in female athletes, but a consensus on the effectiveness of prophylactic knee braces has not been established. The lower-limb muscles are believed to play an important role in stabilizing the knee joint. The purpose of this study was to investigate the changes in lower-limb muscle function with prophylactic knee bracing in male and female athletes during landing. Fifteen recreational athletes performed double-leg drop landing tasks from 0.30m and 0.60m with and without a prophylactic knee brace. Motion analysis data were used to create subject-specific musculoskeletal models in OpenSim. Static optimization was performed to calculate the lower-limb muscle forces. A linear mixed model determined that the hamstrings and vasti muscles produced significantly greater flexion and extension torques, respectively, and greater peak muscle forces with bracing. No differences in the timings of peak muscle forces were observed. These findings suggest that prophylactic knee bracing may help to provide stability to the knee joint by increasing the active stiffness of the hamstrings and vasti muscles later in the landing phase rather than by altering the timing of muscle forces. Further studies are necessary to quantify whether prophylactic knee bracing can reduce the load placed on the ACL during intense dynamic movements.
Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Australia.
Katie A
KA
Ewing
Auckland Bioengineering Institute, University of Auckland, New Zealand; Department of Engineering Science, University of Auckland, New Zealand.
Justin W
JW
Fernandez
Gait, Balance & Falls Research Group, Institute of Sport, Exercise and Active Living, Victoria University, Melbourne, Australia.
Rezaul K
RK
Begg
Department of Medicine (Royal Melbourne Hospital), The University of Melbourne, Melbourne, Australia.
Mary P
MP
Galea
Department of Mechanical Engineering, Melbourne School of Engineering, The University of Melbourne, Australia. Electronic address: pvlee@unimelb.edu.au.
Peter V S
PVS
Lee
D000070598:Anterior Cruciate Ligament Injuries / Q000517:prevention & control; D001915:Braces; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D009068:Movement; D009132:Muscles / Q000502:physiology*; D013177:Sports; D055815:Young Adult
ACL injury; Injury prevention; Knee bracing; Muscle force; Musculoskeletal modeling