Concentric vs Eccentric Full Can Exercise in Partial Rotator Cuff Tears

This study aims to compare the effects of concentric and eccentric full can exercises on supraspinatus muscle architecture in individuals with partial rotator cuff tears. Rotator cuff tears are a common cause of shoulder pain and functional limitation. The supraspinatus muscle plays a key role in shoulder movement and stability, and its structure may be affected in individuals with partial tears. Exercise-based rehabilitation is widely used in the conservative management of these conditions. The full can exercise is commonly prescribed to selectively activate the supraspinatus muscle. However, the effects of different contraction types, specifically concentric and eccentric exercises, on muscle structure and clinical outcomes are not fully understood. In this study, participants will be randomly assigned to either a concentric or eccentric full can exercise group. Both groups will receive a standard physiotherapy program, including therapeutic ultrasound and transcutaneous electrical nerve stimulation (TENS), in addition to the assigned exercise protocol. The intervention will last for 6 weeks, with sessions performed three times per week. Outcomes will be assessed before and after the intervention. The primary outcome is the change in supraspinatus muscle pennation angle measured by ultrasound imaging. Secondary outcomes include muscle architecture parameters, pain intensity, range of motion, muscle strength, functional status, and kinesiophobia. The findings of this study may help improve exercise selection in the rehabilitation of individuals with rotator cuff tears.