Pectoralis Major: The Powerful Chest and Shoulder Muscle
The pectoralis major, a prominent muscle in the chest and shoulder region, plays a crucial role in upper body strength and mobility. This thick and fan-shaped muscle originates from the clavicle and sternum and inserts into the humerus. With multiple heads, the pectoralis major is responsible for various movements of the arm.
Serratus Anterior: The Small Shoulder Muscle with Big Functions
The serratus anterior muscle, though small in size, plays a significant role in shoulder movement. It originates from the front of the upper ribs and attaches to the scapula. This muscle can be divided into three sections: the superior, intermediate, and inferior.
One of the primary functions of the serratus anterior is to facilitate arm rotation forward. It accomplishes this by pulling the scapula forward over the rib cage. Additionally, it is crucial for elevating and upwardly rotating the arm.