Shoulder muscles anatomy

A list of shoulder muscles with origin, insertion, functions, pain locations and strength tests:

Back Shoulder Muscles

• Trapezius elevates and depresses the shoulder and brings together (retracts) the shoulder blades.
• Deltoid (posterior and middle head) moves the upper arm sideways (abduction), brings it to the body (adduction), extends it backwards and rotates it outwards (external rotation).
• Subscapularis rotates the upper arm inwards (internal rotation).
• Supraspinatus moves the upper arm sideways (abduction).
• Infraspinatus rotates the upper arm outwards (external rotation).
• Teres minor rotates the upper arm outwards and brings it to the body (abduction).
• Levator scapulae elevates the shoulder.
• Teres major extends the upper arm backwards and rotates it inwards (internal rotation).
• Rhomboid major and minor bring together (retract) the shoulder blades.
• Serratus anterior moves the shoulder blades apart (protraction).
• Triceps brachii extends the upper arm backwards and moves it toward the body (adduction).

Front Shoulder Muscles

• Deltoid (anterior head) flexes the upper arm forwards and rotates it inwards (internal rotation).
• Pectoralis minor draws the shoulder blade forwards and downward.
• Coracobrachialis flexes the upper arm forwards.
• Biceps brachii flexes and supinates the forearm and slightly flexes the upper arm in the shoulder.

Sources:

• eHealthStar
• GetBodySmart