Which muscle is primarily responsible for protraction of the scapula?

The serratus anterior is the primary muscle responsible for the protraction of the scapula. This muscle originates from the upper ribs and inserts onto the medial border of the scapula, playing a critical role in moving the scapula forward around the rib cage. Protraction refers to the movement of the scapula away from the spine, which is essential for actions such as pushing and reaching forward.

The serratus anterior also helps to stabilize the scapula against the thoracic wall, which is particularly important during activities that involve lifting the arms overhead. Its action is often emphasized in exercises targeting functional movement patterns, such as push-ups or overhead presses, where protraction is necessary to maintain proper scapular positioning and shoulder mechanics.

Other muscles listed, such as the rhomboids, levator scapulae, and mid/lower trapezius, have different actions. The rhomboids are more involved in retracting the scapula, while the levator scapulae primarily elevates the scapula. The mid and lower trapezius assist in retraction and depression of the scapula rather than protraction. Understanding the specific action of the serratus anterior is key for both functional movement and rehabilitation contexts.