BFRT in Adolescents After ACL Reconstruction

Inclusion Criteria: 1. Adolescent male and female patients, age 12-18 2. Skeletally mature at time of diagnosis, with closed growth plates, as determined via standard clinic x-ray imaging (this specification automatically excludes pre-pubescent children. 3. Underwent transphyseal ACLR with quadriceps tendon autograft with one of three sports orthopedic surgeons at CHOA 4. Completed pre-surgery strength assessment of bilateral quadriceps, hamstrings, hip abductor and hip adductor musculature. 5. English-speaking adolescents and parents of all races and ethnicities (after preliminary data is achieved, PI will coordinate a larger multi-center study that will include all non-English speaking participants. Exclusion Criteria: 1. Skeletally immature patients with open growth plates, as determined via standard clinic x-ray imaging 2. Concomitant procedures performed during ACLR which require weight-bearing restrictions (i.e. meniscus repair, microfracture, multi-ligament knee reconstruction) 3. History of previous knee surgery 4. History of cardiovascular disease (e.g. coronary artery disease, unstable hypertension, vascular endothelial dysfunction, peripheral artery disease, varicose veins) 5. ICD-10 diagnosis of bleeding disorder (e.g. hemophilia or blood clotting disorder) or use of anticoagulants or other medications that may affect blood clotting 6. Inability to adhere to treatment protocol (as described in study procedures, BFR-LLT treatment requirements) 7. Any adverse events intra-operatively or post-operatively that lead to delay in care, including infection 8. Failure to adhere to attendance requirements as detailed below: * Attend first PT visit (PTV) within 5 days post-surgery * Attend a minimum of 20 total PTVs during weeks 1-16 post-surgery