Blood Flow Restriction Training in Patients With Rotator Cuff Tendinopathy: A Randomized, Assessor-Blinded, Controlled Trial

Objectives: To investigate the effects of low-load blood flow restriction (BFR) training on shoulder muscle thickness, rotator cuff (RC) strength, and shoulder symptoms in patients with RC tendinopathy. Design: A randomized, assessor-blinded, controlled trial. Settings: Physiotherapy clinic at a university. Participants: Twenty-eight patients were randomized into an 8-week (2 times/week) shoulder rehabilitation, that is, BFR or non-BFR group. Interventions: BFR training. Main outcome measures: (1) RC, deltoid, scapula retractor, and biceps muscle thicknesses and shoulder internal rotation (IR) and external rotation (ER) strengths. (2) Shoulder pain/function. Results: The BFR group had a greater increase in biceps muscle thickness ( P = 0.002) and shoulder IR strength at 60 degrees/s ( P = 0.040) than the non-BFR group. No differences between the 2 groups were observed in other measurements. Significant improvements in supraspinatus, infraspinatus, and scapula retractor muscle thicknesses and in shoulder ER and IR strengths were observed over time in both the groups (all P < 0 .05). Also, shoulder pain decreased and shoulder function increased over time in both the groups (all P < 0 .05). Conclusions: Low-load BFR training resulted in a greater increase in biceps thickness and shoulder IR strength compared with the non-BFR group in patients with RC tendinopathy. However, there was no superiority of either exercise training regarding the RC, scapula retractor, deltoid muscle thicknesses, or improvements in shoulder ER strength and shoulder pain/function. Clinical Trial Registry Name and Registration Number: The study was registered in ClinicalTrials.gov named Blood Flow Restriction Training in Patients with Shoulder Pain and the registration number is NCT04333784.