Snapping scapula is a condition where a grinding sensation and a crackling or snapping sound occurs with movement of the scapula (shoulder blade).
The scapula is a broad triangular bone attached to the body by strong muscles. It forms the foundation for movements of the arm.
We tend to think of the scapula as frozen in place. The reality is that the scapula has a large range of movement, and is responsible for more than one-third of shoulder mobility. This movement is possible due to the bursa located between the scapula and ribcage of the thoracic spine.
A bursa is a fluid-filled sac that cushions body tissues from friction associated with movement. When bursa sacs become inflamed, the condition is called bursitis.
Snapping scapula is usually a harmless condition that is caused by grating or rubbing of the scapula against an inflamed bursa or scar tissue under the scapula.
Previous injuries to the shoulder or upper back can lead to muscle strength imbalances that may contribute to snapping scapula syndrome. This condition is usually associated with contact sports or previous injury. If pain is present, it is usually curable with treatment.
Snapping scapula can start when the tissues between the scapula and shoulder blade thicken from inflammation.
The inflammation is usually caused by repetitive movements such as swimming or tennis.
In other cases, the muscles under the scapula have shrunk from weakness or inactivity. The scapula bone then rides more closely to the rib cage. This means the scapula bumps or rubs on the rib bones during movement.
Changes in the alignment or contour of the scapula or ribs can also cause snapping scapula. When a fractured rib or scapula isn’t lined up just right, it can cause a bumpy ridge that produces the characteristic grind or snap as the scapula moves over the chest wall.
Grinding and snapping can also happen if there are any abnormal curves, bumps or ledges on the upper edge of the scapula closer to the center of the back.
Any time there is an abnormality in the bone, one of the body’s possible responses is to form a bursa. The new bursa may then become inflamed, causing the symptoms of bursitis.
Grating, grinding or snapping may be heard or felt along the edge or undersurface of the scapula as it moves along the chest wall. These grinding sensations are also called crepitus. Often, these sensations cause no pain.
Scapula bursitis, on the other hand, is painful whether or not there is any crepitus in the joint. The sore bursa is usually tender to the touch, and the tissue in the sore area often feels thick.
Treatment for snapping scapula syndrome consists of strengthening exercises for scapula stability, and modification of the activities contributing to pain.
Chiropractic adjustment of the thoracic spine and rib cage can often eliminate symptoms. Rarely surgery or corticosteroid injection is required to treat the inflamed bursa.