Effect of strengthening lower trapezius muscle on scapular tipping in patients with diabetic frozen shoulder: A randomized controlled study

Background: The muscle imbalances between upper and lower trapezius muscle activity are related to abnormal scapular motion in patients with frozen shoulder. This explains the importance of rehabilitation of the lower trapezius muscle in addition to common stretching and mobilizing treatment protocols for patients with frozen shoulder. Purpose: This study aims to investigate the effect of additional strengthening exercises of lower fibers of trapezius muscle on the scapular tipping in patients with Diabetic Frozen Shoulder (DFS). Subjects and Methods: Thirty patients with DFS were randomly assigned into two equal groups A and B. Both groups received a traditional physical therapy program, however group B additionally received strengthening exercises for lower fibers of trapezius. Baseline and post-treatment assessment for the scapular tipping were evaluated by using (A-T) distance test. Results: After treatment; mixed design MANOVA revealed significant improvement in scapular tipping (A-T) distance from supine position, supine position with scapula retraction, standing position, and standing position with scapula retraction, for group B more than group A (P<0.05). There were significant improvements in scapular tipping when comparing the post-treatment mean value with pretreatment in group B only (P<0.05). Conclusion: Strengthening of the lower trapezius fibers plus traditional physical therapy program yields improvement in scapular tipping in patients with DFS more than traditional physical therapy alone