Serratus Anterior

The serratus anterior wraps from the ribs around to the front inner edge of the shoulder blade. It protracts the shoulder blade (reaches it forward) and, crucially, holds it flat against the rib cage while rotating it upward during overhead reaching.

When it is weak the inner border of the shoulder blade lifts off the ribs — "winging" — and overhead movement becomes less stable. It works as a team with the lower trapezius to control the shoulder blade from below.

It is trained with press-plus, wall slides, and reaching drills that emphasize keeping the shoulder blade flat and moving smoothly. See the shoulder exercises.