Posterior Shoulder Muscle Actions

PT605 Anatomy, Oregon Tech

Upper Trapezius

Scapular elevation, retraction, upward rotation.

Middle Trapezius

Scapular retraction

Lower Trapezius

Scapular depression, upward rotation, retraction, posterior tilt

Levator Scapulae

Scapular elevation, retraction, downward rotation.

Rhomboid (Major, Minor)

Scapular elevation, retraction, downward rotation.

Latissimus Dorsi

Shoulder extension, adduction, internal rotation, scapular downward rotation (when attached)

Teres Major

Shoulder extension, adduction, internal rotation, depresses humeral head to allow for normal shoulder abduction (DHH), holds head of humerus in glenoid fossa (HHH)

Teres Minor

Shoulder extension, adduction, external rotation, depresses humeral head to allow for normal shoulder abduction (DHH), holds head of humerus in glenoid fossa (HHH).

Supraspinatus

Shoulder abduction, depresses humeral head to allow for normal shoulder abduction (DHH), holds head of humerus in glenoid fossa (HHH).

Infraspinatus

Shoulder external rotation, depresses humeral head to allow for normal shoulder abduction (DHH), holds head of humerus in glenoid fossa (HHH).

Subscapularis

Shoulder internal rotation, depresses humeral head to allow for normal shoulder abduction (DHH), holds head of humerus in glenoid fossa (HHH).