Low-Load Blood Flow Restriction Training as an Alternative to Heavy-Load Resistance Training in Early-Stage Rehabilitation Following Bone–Patellar Tendon–Bone Anterior Cruciate Ligament Reconstruction: A Randomized Controlled Trial

OBJECTIVE: To compare the effects of low-load blood flow restriction training (LL-BFRT) and heavy-load resistance training (HLRT) on quadriceps and hamstring strength, knee pain, joint effusion, and range of motion following bone–patellar tendon–bone (BPTB) anterior cruciate ligament (ACL) reconstruction. DESIGN: Randomized controlled trial. METHODS: LL-BFRT and HLRT included 12 weeks of biweekly strength training. Quadriceps and hamstring strength, measured in Newton-meters per kilogram, was assessed at 60°/s, 180°/s, and 300°/s at baseline and final follow-up. At final follow-up, knee pain, joint effusion, and range of motion deficits were assessed. RESULTS: Of 28 patients, 23 completed the study. Study groups were comparable at baseline. At final follow-up, no significant differences were observed in quadriceps strength at 60°/s (2.7 and 3.1, p = 0.738), 180°/s (2.3 and 2.8, p = 0.387), and 300°/s (2.2 and 2.8, p = 0.387) as well as in hamstring strength at 60°/s (3.2 and 3.1, p = 0.738), 180°/s (3.2 and 2.9, p = 0.738), and 300°/s (2.8 and 2.6, p = 0.738) for the LL-BFRT and HLRT groups, respectively. Similarly, no significant differences were found for knee pain (14.3% and 35.7%, p = 0.380), joint effusion (7.1% and 35.7%, p = 0.444), flexion deficit (7.1% and 28.6%, p = 0.426), and extension deficit (0.0% and 14.3%, p = 0.478). CONCLUSION: LL-BFRT in the early phase of rehabilitation following BPTB ACL reconstruction demonstrated similar muscle strength, knee pain, joint effusion, and range of motion compared with HLRT. These results support LL-BFRT as a safe alternative when HLRT cannot be performed. JOSPT Open 2026;4(2):166-173. Epub 8 January 2026. doi:10.2519/josptopen.2026.0185