Can Blood Flow Restriction Therapy Improve Strength and Muscle Cross-Sectional Area for Shoulder External Rotators Better Than Exercise Alone?

This 8-week study will investigate whether the application of blood flow restriction (BFR) therapy augments rotator cuff strength in untrained individuals. This is a RCT with subjects randomized to a BFR or a non-BFR group. Both groups will perform the same training program 2 times a week over 8 weeks with one group performing the lower extremity exercises under occlusion (i.e., BFR applied to the proximal thigh of the dominant leg).

Prior to starting the study the subjects will have their strength assessed by a blinded physical therapist using a hand held dynamometer. The muscles assessed will be the: quadriceps, the hamstrings, the supraspinatus, and the external rotators of the shoulder. Another blinded physical therapist will assess the cross-sectional area of the quadriceps and the supraspinatus tendon using ultrasonography. These tests will be repeated at the conclusion of the study.

Subjects' training weight will be 30% of their 1 repetition max (1RM). 1RM will be determined using hand held dumbbells for the shoulder exercises and machines (knee extension, knee curl machines) for the lower extremity exercises.

Subjects will be randomized to either the BFR or non-BFR group. Subjects in the BFR group will perform the lower extremity exercises under occlusion (i.e., BFR applied to the proximal thigh of the dominant lower extremity). Both groups will perform 4 sets of each lower extremity exercise for 30/15/15/15 reps. After completing the lower extremity exercises the subjects will perform the shoulder exercises (scaption, sidelying external rotation) for 3 sets of 15 repetitions each. The shoulder exercises will not be performed with BFR in either group.