The Association Between Shoulder Pain and Rotator Cuff Strength Loss: A Cross-Sectional Study

Abstract

Background: Rotator cuff-related shoulder pain (RCRSP) is the most common shoulder complaint. The interplay between shoulder pain and rotator cuff (RC) strength loss needs further investigation.
Objective: To investigate the association between shoulder pain intensity and RC muscle strength deficits among patients with RCRSP, to clarify whether pain-related inhibition contributes to functional impairment.
Methods: Fifty patients with RCRSP had enrolled to this study from orthopedic physiotherapy outpatient clinic, with mean age of 35 years. They were assessed for shoulder pain and disability using shoulder pain and disability index (SPADI) and isometric RC strength using hand-held dynamometer (HHD).
Results: There was significant, negative, fair correlation between isometric strength of supraspinatus, infraspinatus/teres minor, and subscapularis and shoulder pain and disability (r=-0.29 to -0.41, P<0.05).
Conclusion: Rotator cuff isometric strength deficits were evident in patients with RCRSP and were more closely related to pain. These findings suggest that early rehabilitation may emphasize pain reduction together with active exercises.