The serratus anterior muscle is a broad, flat muscle located in the lateral region of the chest. It originates at the medial border of the scapula (shoulder blade) and inserts into the anterior (front) surfaces of the upper eight or nine ribs. The serratus anterior muscle is one of the muscles that make up the chest wall, and is commonly known as the "boxer's muscle" because it is visible on the sides of the chest when the arms are raised.

The main function of the serratus anterior muscle is to protract (move forward) the scapulae, and upwardly rotate them. This movement is essential for activities such as reaching overhead, and helps to provide stability and support for the shoulder joint. The serratus anterior muscle also helps to stabilize the scapulae, and assist in abduction (movement away from the midline of the body) of the arm.

In everyday life, the serratus anterior muscle is used in many activities that involve protraction and upward rotation of the scapulae, such as reaching overhead or pushing against a heavy object. It is also used in activities that require stability and support for the shoulder joint, such as carrying a heavy backpack or lifting a heavy object.