Function

Serratus anterior has a number of functions:

• protraction of the shoulder girdle. This movement is exemplified by the forward elongation of the entire arm when punching.
• rotation or the scapula laterally and superiorly. This action elevates the glenoid fossa superiorly and as such, it is vital for raising the arm above the level of the shoulders. The lower digitiations, which insert into the inferior angle of the scapula, are the key elements for this movement.
• stabilisation of the scapula. Contraction of serratus anterior draws the scapula against the chest wall. This facilitates other muscles which are attached to the scapula to use it as a fixed point for their actions upon the humerus e.g. teres major. Weakness or absence of serratus anterior function can cause winging of the scapula.