Lifecraft
Shoulder

Shoulder

Posterior Deltoid

Deltoideus pars spinalis

The rear head of the deltoid; dominant in pulling and reverse-fly movements.

Function
Shoulder extension, external rotation and horizontal abduction.
Origin
Spine of the scapula.
Insertion
Deltoid tuberosity of the humerus.

Synergists / Antagonists

Exercises that train this muscle