Strength and endurance of the rotator cuff: Normal subjects versus those with shoulder pain

Abstract

This study aimed to develop a method for testing endurance of the shoulder external rotator (ER) muscles and to see if differences exist between shoulder strength and endurance between those with and without shoulder pain. 45 subjects were tested and their maximum ER strength was recorded via hand held dynamometer. Dumbbells representing 25% of the maximum ER strength were used for the endurance test, and time holding an isometric contraction was recorded. Maximum strength and endurance values between groups were then compared. The results show there is no significant difference in ER strength between participants with and without shoulder pain. However, a statistically significant difference in ER endurance between the painful/dominant shoulders of the experimental group, and the non-painful/dominant shoulders of the control group was found.