Blood Flow Restriction (BFR) is a specialized technique used by physical therapists to enhance the benefits of low-load resistance exercise. The method involves applying a specialized pneumatic cuff or tourniquet to the most proximal (uppermost) part of a limb (arm or leg) to partially restrict arterial blood flow into the muscle and fully restrict venous blood flow out of the muscle. This creates a local hypoxic (low oxygen) environment in the muscle tissue. The intent of BFR is to safely simulate the physiological effects of high-intensity training while only lifting loads of 20–40% of a one-repetition maximum (1-RM). This low-load stimulus, combined with the metabolic stress created by BFR, triggers a cascade of chemical signals that promote muscle strength and hypertrophy (growth), accelerate tendon and bone healing, and minimize joint stress. BFR is particularly valuable for patients recovering from surgery or injury where heavy lifting is contraindicated, allowing them to gain or maintain significant strength and muscle mass without stressing the healing tissue.