Pteroscapula, also known as serratus anterior, can be subdivided into three groups: upper, middle and lower, which have three different functions.

The main function of the middle and upper part is to make the scapula stretch forward, and the lower part can make the scapula rotate outward. When punching or lifting on the arm, the scapula can rotate upward. This muscle is connected to the scapula, so it can play a stable role in the movement of the scapula.