Deltoid

Origin

Clavicle (anterior head), acromion (medial head) and spine of scapula (posterior head)

Insertion

Lateral surface of humerus (nearly half way down)

Joint crossed

Shoulder (glenohumeral joint)

Joint actions

Anterior fibres flex the shoulder and assist in horizontal flexion

All fibres abduct the shoulder (emphasis on medial fibres)

Posterior fibres extend the shoulder and assist in lateral rotation

Exercise example(s)

Shoulder Press, Bench Press, Push Ups, Single Arm Row

Stretch example(s)

Standing Posterior Deltoid stretch