Serratus anterior

A muscle that plays a crucial role in shoulder movement and upper limb stability.

The serratus anterior is a fan-shaped muscle located on the lateral side of the thorax. It originates from the upper eight or nine ribs and extends to attach to the medial border of the scapula. This unique arrangement allows the muscle to play an essential role in various upper body movements.

Terminologia Anatomica

musculus-serratus-anterior

System

Muscular system

Function

The primary function of the serratus anterior is to stabilize the scapula (shoulder blade), allowing for the smooth and efficient movement of the shoulder joint. It is especially important in actions involving pushing and lifting, where it helps to keep the scapula firmly against the thoracic wall. This muscle is also crucial during arm elevation, such as when performing overhead movements, as it allows for full range of motion by preventing winging of the scapula. Additionally, the serratus anterior assists in the upward rotation of the scapula, enabling activities like reaching high above the head. In summary, the serratus anterior ensures proper biomechanics of the shoulder girdle, thereby facilitating coordinated movements of the upper limb.

Location

Situated on the side of the thorax, the serratus anterior covers the lateral surface of the rib cage. It stretches from the first rib near the spine, continuing down the lateral aspect of the ribs, forking out into individual slips that insert along the medial border of the scapula. Its positioning allows it to act as a bridge between the rib cage and the scapula, playing a pivotal role in both stability and movement of the shoulder girdle. The muscle can be visualized as 'saw-toothed' due to its serrated appearance created by its finger-like projections, which gives it its namesake.

Did You Know?

The serratus anterior is often referred to as the 'boxer's muscle' because it is heavily utilized in punching movements.
Weakness in the serratus anterior can lead to scapular winging, where the shoulder blade protrudes abnormally away from the back.
Strengthening the serratus anterior can improve overall shoulder stability and reduce the risk of injuries.