Shoulder and Arm Muscles: Origins, Insertions, Actions

Posted on Mar 12, 2025 in Physiotherapy

Deltoid

Origin: Anterior edge of the collarbone, lateral acromion edge.

Insertion: Deltoid tuberosity.

Action: Horizontal flexion, abduction, extension horizontal.

Supraspinatus

Origin: Supraspinous fossa of the scapula.

Insertion: Superior facet of greater tuberosity.

Action: Produces abduction of the shoulder.

Subscapularis

Origin: Subscapular fossa.

Insertion: Articular capsule of the lesser tuberosity of humerus.

Action: Internal rotation stabilizer.

Infraspinatus

Origin: Infraspinous fossa of the scapula.

Insertion: Middle facet of the greater tuberosity.

Action: External rotation stabilizer.

Teres Minor

Origin: Outer border of the scapula.

Insertion: Greater tubercle of the humerus articular capsule.

Action: External rotation stabilizer.

Teres Major

Origin: Inferior 1/3 edge of the scapula.

Insertion: Lesser tuberosity.

Action: Adduction of the shoulder.

Pectoralis Major

Origin: Anterior surface of sternum and collarbone (1/2), 6 to 7 first ribs.

Insertion: Crest of the greater tuberosity.

Action: Adduction, internal rotation of the humerus.

Biceps Brachii

Origin: Short head: coracoid process; Long head: glenoid.

Insertion: Radial tuberosity.

Action: Flexes the shoulder.

Brachialis

Origin: Anterior surface of the humerus.

Insertion: Tuberosity and coronoid process of ulna.

Action: Flexes the elbow joint.

Coracobrachialis

Origin: Coracoid process of the scapula.

Insertion: Mean portion of the shaft of the humerus.

Action: Flexion and adduction of the shoulder joint.

Triceps Brachii

Origin: Long head: infraglenoid tubercle of the scapula; Lateral head: below radial groove; Medial head: 2/3 and posterior distal humerus.

Insertion: Olecranon and antebrachial fascia.

Action: Extends the elbow joint.

Brachioradialis

Origin: Distal 2/3 supracondylar ridge.

Insertion: Radial styloid.

Action: Flexes the elbow joint.

Supinator

Origin: Lateral epicondyle of the humerus.

Insertion: The radio body, anterior and posterior.

Action: Forearm supination.

Palmaris Longus

Origin: Common flexor medial epicondyle.

Insertion: Transverse carpal ligament.

Action: Wrist flexion.

Flexor Carpi Radialis

Origin: Antebrachial fascia.

Insertion: Base of 2nd and 3rd metacarpals.

Action: Flexion and radial deviation of wrist.

Flexor Carpi Ulnaris

Origin: Humeral medial epicondyle.

Insertion: Internal border olecranon.

Action: Flexion and ulnar deviation of wrist, adduction.

Extensor Carpi Radialis Longus

Origin: Distal supracondylar ridge.

Insertion: Radial edge of the dorsal surface of the base of 2nd metacarpal.

Action: Extension and radial deviation of wrist, abduction.

Extensor Carpi Radialis Brevis

Origin: Common extensor tendon at the epicondyle.

Insertion: Dorsal surface of the base of the 3rd metacarpal.

Action: Extension and radial deviation of wrist, abduction.

Extensor Carpi Ulnaris

Origin: Posterior border of ulna and fascia of forearm.

Insertion: Edge ulnar base of the 5th metacarpal.

Action: Extension and ulnar deviation of wrist, adduction.

Rhomboid Major

Origin: Spines of the second to fifth dorsal vertebra.

Insertion: Medial border of the scapula.

Rhomboid Minor

Origin: Spinous processes of seventh cervical and first dorsal vertebra.

Insertion: Spine of the scapula.

Action: Adduction and elevation of the scapula.

Latissimus Dorsi

Origin: Spinous processes of the last 6 thoracic vertebrae.

Insertion: Intertubercular groove of humerus.

Action: Internal rotation, adduction.