A protruding shoulder blade, known as scapular winging, occurs when one or both shoulder blades lift away from the back. This visible condition can cause concern or discomfort. This article explores its common causes and when to seek medical guidance.
What a Protruding Shoulder Blade Means
A “winged scapula” describes the appearance when the inner border or lower angle of the shoulder blade lifts away from the rib cage, creating a wing-like projection. This is often noticeable during arm movements like pushing or overhead activities.
The scapula, or shoulder blade, is a flat bone connecting the upper arm to the collarbone, playing a role in shoulder movement and stability. A network of muscles coordinates its movements and secures it against the chest wall. When these muscles weaken or become paralyzed, they cannot hold the scapula flat, leading to its protrusion and affecting shoulder function.
Common Reasons for Scapular Winging
Scapular winging primarily results from issues affecting the nerves or muscles responsible for stabilizing the shoulder blade against the back. Damage to specific nerves can impair the muscles they control, leading to weakness or paralysis.
The long thoracic nerve innervates the serratus anterior muscle, important for holding the scapula against the rib cage and enabling overhead arm movement. Injury to this nerve, often from trauma, repetitive stretching, or viral infections, can cause the medial border of the scapula to protrude, particularly during pushing motions.
The dorsal scapular nerve controls the rhomboid muscles, which stabilize the scapula. Damage to this nerve can cause subtle winging where the scapula rotates laterally.
The spinal accessory nerve supplies the trapezius muscle, which helps elevate and rotate the scapula. Injury to this nerve can lead to shoulder drooping and scapular winging.
Beyond nerve damage, general muscle weakness or imbalance in the muscles surrounding the shoulder blade can also contribute to scapular winging. Weakness or imbalance in these muscles, whether from overuse, lack of exercise, or atrophy, can prevent the scapula from being held properly, leading to abnormal movement or protrusion.
Shoulder girdle instability or injury can also indirectly lead to scapular winging. Conditions like rotator cuff tears or shoulder dislocations can alter shoulder biomechanics, straining scapular stabilizing muscles. This can lead to muscle fatigue and abnormal scapular movement.
Prolonged poor posture, such as a slumped or forward-leaning head and shoulders, can create muscle imbalances over time. This sustained strain can weaken the muscles that keep the scapula flat, making it more prone to winging. In some instances, scapular winging can also be present from birth due to anatomical variations or underlying muscular dystrophies.
When to Consult a Healthcare Professional
If you notice a shoulder blade visibly sticking out or experience associated symptoms, consult a healthcare professional. This is important if winging is accompanied by pain, numbness, or weakness in the shoulder, arm, or neck. Seek medical attention if the condition affects daily activities, limits range of motion, appeared suddenly after an injury, or progressively worsens.
During a consultation, a healthcare professional will conduct a physical examination, review your medical history, and may use diagnostic tools like electromyography (EMG) or imaging studies to identify nerve damage or muscle pathology.
Addressing a Winged Scapula
The approach to addressing a winged scapula depends on its underlying cause. Physical therapy is a key part of the treatment plan for many individuals. Therapists design exercise programs to strengthen weakened muscles (e.g., serratus anterior, rhomboids) and stretch tight ones, restoring muscle function and improving scapular stability.
Pain management strategies, including anti-inflammatory medications or applying ice/heat, can alleviate discomfort. Bracing or taping techniques may provide temporary support, offering relief and facilitating physical therapy.
Surgical intervention is a last resort, reserved for severe cases where conservative treatments fail or when there is nerve damage or muscle dysfunction. Procedures range from nerve or muscle transfers to, rarely, static stabilization like fusing the scapula to the ribs.