What is snapping scapula syndrome?

Snapping scapula syndrome is a fairly rare condition where the shoulder blade thumps, grates, or snaps as it moves along the chest wall. It can happen when the bursa between the shoulder blade and chest wall becomes inflamed. (A bursa is a lubricated sac that cuts down on friction between muscles, tendons, and bones during movement.) People who have had a fractured rib or shoulder blade sometimes feel grating because the bones may have healed out of alignment. Weak muscles under the shoulder blade can increase the chances of having snapping scapula syndrome because there is less muscle padding between the shoulder blade and chest wall.