Which movement is primarily limited due to shoulder impingement?

Shoulder impingement primarily affects the movement of abduction. This condition occurs when the tendons of the rotator cuff become irritated and inflamed as they pass through the shoulder joint, particularly between the acromion and the humeral head. As a result, when a person attempts to raise their arm above their head—especially during abduction—there is increased pressure that leads to pain and restricted movement.

During abduction, the shoulder joint requires a coordinated movement of the rotator cuff muscles to stabilize the head of the humerus within the glenoid socket, while also allowing for the arm to rise. In cases of impingement, this delicate balance is disrupted, leading to difficulty in raising the arm and often resulting in pain. Patients typically report that lifting their arm contributes to discomfort, especially when the arm is elevated at or above shoulder level.

The other movements—internal rotation, external rotation, and flexion—can also be affected but are not primarily restricted by shoulder impingement. Specifically, internal and external rotations may still be performed, although they might be painful due to the surrounding inflammation. Flexion can occur, but may also trigger discomfort as the shoulder does not function optimally under these conditions. Therefore, while several movements