This condition is a compression of the suprascapular nerve which can cause instability in the shoulder joint that can lead to more severe problems. The suprascapular nerve is a motor nerve that controls the functions of two of the main muscles on the shoulder blade.

The suprascapular nerve can become compressed because of an injury or from repetitive stress placed on the shoulder, particularly during athletic activities such as baseball and volleyball. Pressure may also be placed on the nerve from a cyst or tumor that has developed in the shoulder.

Symptoms can vary from pain, weakness in the supraspinatus and infraspinatus muscles, or atrophy of these muscles.

Treatment options can include rest, anti-inflammatory medications, stretching and conditioning exercises, and physical therapy. Severe cases may require surgery.