Scapula is an amazing anatomical structure. It is suspended over the ribs between the spine and the arm by only two ligaments. There isn’t a real joint between the scapula and the trunk. Three layers of muscle and bursae (plural for bursa) support this structure. The bursae are small fluid-filled sacs designed to reduce friction between muscle or tendon and bone. These layers (superficial, intermediate, and deep) form a smooth surface for the scapula to move, glide, and rotate over. Because there is movement but no actual joint, this connection is considered a pseudojoint.
Snapping scapula syndrome is usually the result of overuse of the arm, poor posture during sports activities, or incorrect joint motion. But it also can be caused by a single episode of trauma to the shoulder blade area. Physical therapists treat the pain, muscle weakness, loss of motion, and soft tissue swelling that can occur with snapping scapula syndrome.
Scapular winging symptoms vary from person to person depending on the underlying cause as well as the muscles and nerves involved. Most people with scapular winging have a shoulder blade that sticks out. This can make sitting in a chair or wearing a backpack uncomfortable.
If the winged scapula is the result of nerve damage, it can cause weakness in the muscles of your neck, shoulders, and arms. That weakness can make lifting, pulling, and pushing heavy objects hard.
Scapular winging often affects your ability to raise your arm above your shoulder. It may also be associated with other symptoms, including:
pain or discomfort in your neck, shoulders, and back
a drooping shoulder
Frozen shoulder typically develops slowly, and in three stages. Each stage can last a number of months.
Freezing stage. Any movement of your shoulder causes pain, and your shoulder’s range of motion starts to become limited.
Frozen stage. Pain may begin to diminish during this stage. However, your shoulder becomes stiffer, and using it becomes more difficult.
Thawing stage. The range of motion in your shoulder begins to improve.
For some people, the pain worsens at night, sometimes disrupting sleep.
A less common cause is the development of a benign tumor called an osteochondroma. Bone spurs, scapular or rib fractures, nerve injuries with muscle wasting and weakness, or other types of tumors have also been linked with the snapping syndrome. And any surgery to the upper quadrant (e.g., breast implants or other breast cosmetic procedures, removal of a rib pressing on a nerve) can result in muscular changes that contribute to the development of the scapular snapping syndrome.
No matter what the cause, the effect is a disturbance in the way the scapula moves over the thoracic wall. This altered movement pattern is called scapular dyskinesis or scapular dyskinesia. Diagnosing the problem can be difficult. There’s no one single test or imaging study that clearly shows what’s going on. Sometimes on visual exam, it’s possible to see some postural changes, asymmetry from one side to the other, or an obvious change in the normal scapulohumeral rhythm as the arm is raised up. The examiner also looks at range of motion, strength, and flexibility. If nerve damage is suspected, electrodiagnostic testing can be ordered.
The most common surgical treatments for scapular winging are nerve and muscle transfers. These surgeries involve taking all or part of a nerve or muscle and moving it to another part of the body. Nerve and muscle transfers for scapular winging usually focus on the shoulder, back, or chest.
Another option is called static stabilization. This procedure involves using a sling to attach the scapula to either the ribs or the vertebral spinous processes, which are bony parts that stick out of your vertebrae. There is a risk that the sling will stretch out over time, causing the winged scapula to return.