The aim of this study is to investigate the effects of shoulder eccentric exercise training on shoulder mobility, rotator cuff strength, pain and dysfunction, scapular kinematics and muscle activation in symptomatic overhead athletes with posterior shoulder tightness.

Overhead athletes commonly have posterior shoulder tightness due to repetitively high tensile loading during overhead throwing. However, intervention studies focused on posterior shoulder tightness in people with subacromial pain are still limited. Additionally, eccentric exercise was thought to improve the eccentric strength and neuromuscular control of posterior shoulder muscles to endure repetitively eccentric loading, which may improve posterior shoulder tightness and decrease the risk of subacromial pain. Nevertheless, no previous study investigated the influence of eccentric exercise on posterior shoulder tightness in overhead athletes. The aim of this study is to investigate the effects of shoulder eccentric exercise training on shoulder mobility, rotator cuff strength, pain and dysfunction, scapular kinematics and muscle activation in symptomatic overhead athletes with posterior shoulder tightness.

Inclusion Criteria:

• Participate in overhead sports over 4 hours per week
• Age between 20 to 50 years old
• Glenohumeral joint range of motion deficit: Shoulder internal rotation loss more than 15 degrees compared to the non-dominant side and total arc of motion loss more than 5 degrees or/and horizontal adduction range of motion lo more than 15 degrees compared to the non-dominant side
• Shoulder impingement syndrome criteria

Exclusion Criteria:

• History of shoulder dislocation, fracture and operation
• History of direct contact in upper extremities or cervical region in the past one month
• Shoulder pain or neurological symptom caused by cervical problem
• VAS more than 5 during shoulder elevation
• Receive treatment for posterior shoulder tightness in the past 3 months