Sometimes a “shoulder” problem isn’t exactly in the shoulder. It may be in the position and movement of the shoulder blade or wing bone called the scapula. Scapular dyskinesia is a term used to describe abnormal scapular position and motion.
Patients with this problem often have a loss of shoulder internal rotation. They may have signs of shoulder impingement. This means some structure in the shoulder complex is getting pinched during motion.
For example, if the scapula is resting too far forward (away from the spine), the head of the humerus can’t slide down inside the socket during upward motion of the arm. As the patient raises his or her arm, the humeral head bumps up against the acromion. The acromion is a ridge of bone across the back of the scapula. It forms a small, protective shelf over the top of the shoulder.
The authors of this article instruct physicians in how to screen the shoulder complex for scapular dyskinesia and core weakness that might cause it. The first step is to visually inspect the scapula for position and balance. If it “wings” out away from the trunk, it’s a sign of abnormal function. This may be caused by muscular inflexibility, weakness, or fatigue or nerve injury.
Three specific tests for core strength and stability are shown. Patient photos of each test along with instructions to carry out the test are included. The scapular assistance test is also pictured and described. These tests help the examiner assess for dyskinesia and its cause.
Using the information gained from the testing procedures, a special exercise program can be prescribed. Muscle weakness and inflexibility can be addressed in the rehab program. The goal is to improve stability and function of the arm.