Effects of Early Rehabilitation Using Blood Flow Restriction and/or Surface Electromyography Biofeedback on Quadriceps Activation and Strength After Anterior Cruciate Ligament Reconstruction: A Multicenter Randomized Controlled Trial

Standardized postoperative ACL rehabilitation only. Begins \~2 weeks after surgery; supervised \~3 sessions/week for 6 weeks. Includes progressive range of motion, quadriceps activation/strengthening, functional drills, and return-to-activity progressions delivered per protocol.

Low-load resistance exercises performed with individualized limb occlusion pressure (LOP) determined each session; target %LOP per protocol. Progresses from isometric to dynamic open/closed-chain tasks. Delivered under supervision \~3 sessions/week for 6 weeks; monitoring of tolerance and adverse events per safety LOP.

Real-time surface electromyography biofeedback to optimize quadriceps recruitment during targeted tasks (e.g., isometric contractions, straight-leg raise, sit-to-stand, mini-squat, gait drills). Visual and/or auditory feedback with progressive targets. Supervised \~3 sessions/week for 6 weeks; outcome assessors remain blinded.