Effects of Blood Flow Restriction Training on the Upper Extremities: A Scoping Review.

High-intensity training leads to muscle growth in the upper extremities but at the expense of a greater risk of damaging joints, ligaments, or tendons due to this region being more prone to injury. In contrast, low-intensity resistance training implements a low load with high repetition, which is safer but yields less muscle hypertrophy and greater time consumption. Blood flow restriction (BFR) training potentially provides a solution as it achieves the muscle growth and strengthening of high-intensity resistance training while safely performing low-intensity resistance training. This technique reduces venous return and arterial blood flow to the targeted limb, creating a physiological environment to induce muscle hypertrophy, increase strength, and prolong endurance while minimizing tissue stress. This study will analyze literature within the past 10 years on the usage of BFR training in the upper extremities. An extensive search on PubMed was performed using the term "blood flow restriction training upper extremity," which resulted in 98 articles that were narrowed down to 17 based on clinical trials and relevance to upper extremities. Results from this study demonstrate that BFR training enhances muscle hypertrophy and strength in the upper extremity muscles, including the biceps brachii and triceps brachii at low loads. Additionally, BFR training has been shown to promote adaptations in non-occluded muscles proximal and contralateral to the cuff location. Clinical applications include postoperative recovery, rehabilitation of rotator cuff injuries, and treatment of tendinopathies. BFR training offers an effective alternative to high-load resistance training for the upper extremities with promising applications in rehabilitation and injury prevention. Future research is necessary to address long-term effects, optimize protocols, and diversify its applications.