Low-load exercise with blood flow restriction improves muscle strength and disability in musculoskeletal conditionsLow-Load Exercise With Blood Flow Restriction Improves Muscle Strength

OBJECTIVES: This systematic review and meta-analysis evaluated the efficacy of low-load exercise with blood flow restriction (LLE-BFR) compared with low-load exercise (LLE) and high-load exercise (HLE) in individuals with musculoskeletal (MSK) conditions on muscle strength, disability and pain intensity. METHOD: Systematic review and meta-analysis of randomised clinical trials (RCTs). Methodological quality and risk of bias were assessed using the Physiotherapy Evidence Database (PEDro) scale and the Cochrane Risk of Bias 2 (RoB 2) tool. DATA SOURCE: Six databases were searched without language restrictions from inception to November 2025, with additional studies identified from reference lists. ELIGIBILITY CRITERIA FOR SELECTING STUDIES: RCTs evaluating LLE-BFR versus LLE or HLE on muscle strength, pain intensity, disability and adverse events in people with MSK conditions. RESULTS: We included 45 RCTs (1652 participants), with 44 RCTs (1607 participants) contributing to meta-analyses (mean PEDro score=6.55; most of the included trials were rated as 'some concerns' across one or more RoB 2 domains). Low-certainty evidence indicated LLE-BFR was superior to LLE for muscle strength (standardised mean difference (SMD)=0.82, 95% CI 0.40 to 1.23) and disability (SMD=0.63, 95% CI 0.36 to 0.89). Moderate-certainty evidence showed no clear difference between LLE-BFR and HLE for muscle strength (SMD=0.08, 95% CI -0.20 to 0.35), and very-low certainty evidence showed no clear difference for disability (SMD=0.66, 95% CI -0.16 to 1.47). Moderate- and low-certainty evidence indicated small, unimportant differences favouring LLE-BFR over LLE (MD=4.45, 95% CI 1.21 to 7.71) and HLE (MD=7.71, 95% CI 1.62 to 13.8) for pain intensity, respectively. Very-low and low-certainty evidence suggested no difference in adverse events between LLE-BFR and LLE (risk ratio, RR=0.92) or HLE (RR=1.08); however, adverse-event monitoring and reporting were inconsistent across trials. CONCLUSION: Low-certainty evidence indicates that LLE-BFR improves muscle strength and disability compared with LLE. Moderate-certainty evidence showed no clear difference in muscle strength compared with HLE, while evidence for disability was very low certainty, precluding firm conclusions. Prediction intervals were wide for several outcomes. Although pain reductions favoured LLE-BFR, these effects were small and unlikely to be clinically meaningful, and evidence regarding adverse events remains limited. PROSPERO REGISTRATION NUMBER: CRD42023423638.