Optimizing Plyometric Training for Functional Recovery Post-ACL Reconstruction

While surgical anterior cruciate ligament reconstruction (ACLR) of the knee restores passive stability, studies are showing consistently poor long-term outcomes. Unusually high risks of early-onset osteoarthritis and re-injury, and low rate of return to sport following ACLR all seem to be related to a chronic tendency to land stiff-legged from a jump or hop, which itself may be due to fear of re-injury. Decreased knee bending for force absorption simultaneously decreases performance level and increases risk for injury and arthritic changes. The purpose of the proposed study is to compare a current best-practice plyometric training program to one utilizing body weight support to increase repetition and improve performance in the initial phases. The investigators hypothesize that we will see larger improvements in absorptive capacity of the knee and better confidence in activity immediately following body weight support training, as well as improved retention of training effects after a two-month period.

Participants will undergo treatment 2 times a week for 8 weeks with plyometric exercises deemed to be consistent with best practice delivered at a standard dosage of sets and repetitions.

Participants will undergo treatment 2 times a week for 8 weeks with plyometric exercises deemed to be consistent with best practice with a treatment volume of sets and repetitions that exceeds standard practice. Higher number of practice trials will be completed with body weight support (BWS) to reduce load. Participants will start at 30 percent of body weight and will be slowly weaned away over time.

Participants will undergo individualized practice exercises of jumping, hopping, and cutting tasks consistent with standard published exercises.

Participants will undergo individualized practice exercises of jumping, hopping, and cutting tasks consistent with standard published exercises while their body weight is supported via adjustable harness.

Inclusion Criteria: speak and understand English age between 12-35 years unilateral anterior cruciate ligament reconstruction between 6-48 months prior activity level greater than or equal to level 5 on the Tegner Activity Scale Exclusion Criteria: Weight in excess of 300 pounds (136 kg) contralateral/bilateral ACL reconstruction or an unreconstructed ACL injury history of a posterior cruciate ligament injury lower extremity of back injury or other condition (e.g. cerebral palsy) that has limited their normal activities of daily living within the last 6 months

Elias ARC, Harris KJ, LaStayo PC, Mizner RL. Clinical Efficacy of Jump Training Augmented With Body Weight Support After ACL Reconstruction: A Randomized Controlled Trial. Am J Sports Med. 2018 Jun;46(7):1650-1660. doi: 10.1177/0363546518759052. Epub 2018 Mar 20.