What action does the serratus anterior perform on the scapula?

The serratus anterior is primarily responsible for protracting the scapula and stabilizing it against the thoracic wall. This muscle originates from the upper eight or nine ribs and inserts along the medial border of the scapula. When the serratus anterior contracts, it pulls the scapula forward around the rib cage, facilitating movement and allowing for proper functioning of the shoulder joint, especially during activities such as reaching and pushing.

Furthermore, the muscle plays a crucial role in upward rotation of the scapula, which is essential for raising the arm above shoulder level. By holding the scapula in place against the thoracic wall, the serratus anterior ensures that the shoulder girdle remains stable during upper limb movements. This stability is critical for maintaining the efficiency of the shoulder complex and preventing injuries.

Understanding the actions of the serratus anterior is important for kinesiology professionals, as it plays a significant role in shoulder mechanics and overall upper body function.