It's Over Serratus anterior

[kay']

The serratus anterior is a muscle that originates on the surface of the upper ribs at the side of the chest and inserts along the entire anterior length of the medial border of the scapula. It plays a crucial role in the movement and stabilization of the scapula, facilitating the upward rotation necessary for the elevation of the arm. It is also involved in protracting the scapula, which is the action of pulling the shoulder blades forward around the rib cage. Weakness or dysfunction in the serratus anterior can lead to conditions like winged scapula, where the shoulder blade protrudes outwards abnormally.

 

[Animecel2D]

When the shoulder girdle is fixed, all three parts of the serratus anterior muscle work together to lift the ribs, assisting with respiration. The serratus anterior, also known as the “boxer's muscle,” is largely responsible for the protraction of the scapula, a movement that occurs when throwing a punch.

 

[Emba]

I have a scapula.