Investigating Strength Effects at the Shoulder Using Blood Flow Restriction

Introduction: The purpose of this study was to assess the effects of blood flow restriction (BFR) on proximal musculature of the upper extremity. This randomized control trial study design used manual muscle testing and one repetition maximum (1RM) as the main outcome measures to test the strength of the pectoralis major, lower trapezius, rhomboid, serratus anterior, and external rotator muscles. Methods: Eleven males completed the following exercises two days per week for four weeks at the student recreation center: bench press plus, scapular retraction, shoulder external rotation (ER), and bent over rows. Six subjects received BFR to their dominant arm and performed four exercises at 20% of their 1RM. Five control (CON) subjects followed the American College of Sports Medicine (ACSM) strength and hypertrophy protocol at 70% of their 1RM. Results: A significant difference was noted in both pectoralis major and lower trapezius strength (p < 0.05) and in 1RM for prone rows for the BFR group. A significant difference was noted in pectoralis major, lower trapezius, and external rotator strength and in 1RM for scapula retraction for the CON group. A significant difference was noted between groups for pre- training for the pectoralis major. Conclusions: Completing BFR at 20% of 1RM produces the same post-training strength gains in the serratus anterior, external rotator, rhomboids, lower trapezius, middle trapezius, and pectoralis major muscles as the implementation of high resistance exercise. Based on the results of this study, lighter weights using a BFR protocol is as effective in gaining strength as using high resistance exercise.