Functional Resistance Training Improves Thigh Muscle Strength after ACL Reconstruction: A Randomized Clinical Trial

• Published in: Medicine and science in sports and exercise Vol. 54; no. 10; pp. 1729 - 1737
• Main Authors: PALMIERI-SMITH, RIANN M., BROWN, SCOTT R., WOJTYS, EDWARD M., KRISHNAN, CHANDRAMOULI
• Format: Journal Article
• Language: English
• Published: United States Lippincott Williams & Wilkins 01-10-2022
• ISSN: 0195-9131; 1530-0315
• DOI: 10.1249/MSS.0000000000002958

Quadriceps weakness is common after anterior cruciate ligament (ACL) reconstruction, resulting in prolonged disability and increased risk for re-injury and osteoarthritis. Functional resistance training (FRT) combines resistance training with task-specific training and may prove beneficial in restoring quadriceps strength. The primary purpose of this study was to determine if a walking specific FRT program (e.g., resisted walking) improves knee strength in individuals after ACL reconstruction.
Thirty participants were randomized into one of three groups: 1) FRT with a customized knee BRACE applied to the ACL leg, 2) FRT with elastic BAND tethered to the ankle of the ACL leg, or 3) a TARGET MATCH condition where no resistance was externally applied. Participants in all groups received training while walking on a treadmill 2-3 times per week for 8 weeks. Isometric knee extension and flexion strength were measured prior to the start of the intervention (PRE), after the intervention (POST), and 8 weeks after intervention completion (POST-2).
The BRACE group had greater knee extensor strength compared with the TARGET MATCH group at POST and POST-2 (p < 0.05). The BRACE group had greater knee flexor strength than the TARGET MATCH group at POST and POST-2 (p < 0.05) and the BAND group at POST (p < 0.05).
FRT applied via a customized knee brace results in improvements in knee extensor and flexor strength after ACL reconstruction. FRT is a beneficial adjuvant to ACL rehabilitation and leads to better strength compared to standard of care.