Deltoid Muscle

The deltoid muscle is used in all side lifting movements and any movement of the humerus on the scapula. It is divided into three portions, anterior, middle and posterior, with the fibres having different roles due to their orientation.

Origin - Outer 1/3 of the clavicle
Acromion process
Spine of the scapula

Insertion - Deltoid tuberosity on the humerus

Actions - Anterior portion - Shoulder flexion and internal rotation
Posterior portion - Shoulder extension and external rotation
All fibres - Shoulder abduction

Innervation - Axillary nerve

Daily uses - Lifting

Example stretches - Anterior shoulder stretch
Posterior shoulder stretch

Example strengthening exercises - Lateral raise
Front raise


















Related muscles categories: