The scapula, or shoulder blade, is a flat, triangular bone on the upper back. Scapular stabilization is the coordinated action of surrounding muscles that hold the bone firmly against the rib cage during movement. This network of muscles controls the scapula’s position, allowing for smooth arm motion and providing a secure anchor for strength and precision.
The Role of the Scapula in Shoulder Movement
The scapula serves as the foundation for arm movements, and a stable base is necessary for proper shoulder function. This relationship is described as the “scapulohumeral rhythm,” a coordinated motion where for every two degrees the arm moves, the scapula moves one degree. This synchronized action ensures the shoulder socket is correctly positioned to support the head of the humerus (the upper arm bone).
This dynamic stability allows for the transfer of energy from the body’s core through the torso to the arm, an action called the kinetic chain. When reaching for an object, throwing a ball, or swimming, the scapula must upwardly rotate, tilt posteriorly, and rotate externally. This complex movement prevents the bones of the shoulder from pinching the rotator cuff tendons, a source of shoulder pain. The muscles responsible, including the serratus anterior and trapezius, work together to guide the scapula.
Signs of Scapular Dyskinesis
When the muscles controlling the shoulder blade do not function correctly, it can lead to abnormal movement known as scapular dyskinesis. One of the most apparent signs is “scapular winging,” where the inner border of the shoulder blade lifts away from the rib cage. This is more noticeable during movements like a push-up or pushing open a heavy door.
Other indicators can be more subtle. You might notice one shoulder appears lower or more forwardly positioned than the other, a condition known as rounded shoulders. This postural imbalance can be accompanied by pain in the shoulder, neck, or upper back. A clicking or snapping sensation, called crepitus, during arm elevation is another symptom. These issues stem from muscle imbalances, where some muscles become tight while others become weak.
Corrective Exercises and Movements
Regaining control of the scapula involves strengthening the stabilizing muscles through specific, controlled exercises. The goal is to retrain the muscles to hold the scapula securely against the thorax. These movements should emphasize proper form and slow, deliberate execution rather than speed or heavy resistance.
A foundational exercise is the scapular push-up, which targets the serratus anterior muscle. Stand facing a wall with your hands placed shoulder-width apart at chest height. Keeping your arms straight, allow your chest to move toward the wall, squeezing your shoulder blades together. Then, push away from the wall, focusing on rounding your upper back to spread the shoulder blades apart. This movement isolates the action of the scapula without bending the elbows.
Another movement is the prone “Y” lift, which strengthens the lower trapezius muscles. Lie face down on the floor with your arms extended overhead in a “Y” position, palms facing down. While keeping your neck neutral, lift your arms off the floor by squeezing your shoulder blades down and back. Hold for a moment before slowly lowering your arms. Initiate the movement from the mid-back muscles, not by arching the lower back.
To target the rhomboids and middle trapezius, which retract the scapula, band pull-aparts are effective. Stand with your feet shoulder-width apart, holding a resistance band with both hands in front of you at chest height, palms down. Keeping your arms straight, pull the band apart by squeezing your shoulder blades together. Control the movement as you return to the starting position.