Muscles Of The Elbow & Radioulnar/forearm Joints

Front 1

Biceps brachii

Back 1

O: coracoid process of scapula; supraglenoid tubercle; upper lip of glenoid fossa

I: radial tuberosity; bicipital aponeurosis

A: elbow flexion; forearm supination; weak GH flexion

I: musculocutaneous n. (C5, C6)

Hint 1

lacertus fibrosis

Front 2

Brachialis

Back 2

O: distal half of anterior shaft of humerus

I: coronoid process of ulna

A: elbow flexion

I: musculocutaneous n. & sometimes branches from radial n. and median n. (C5, C6)

Hint 2

"true" elbow flexion

Front 3

Brachioradialis

Back 3

O: distal two-thirds of lateral supracondylar ridge of humerus

I: styloid process of distal radius (lateral surface)

A: elbow flexion (in neutral position); forearm supination & pronation

I: radial n. (C5, C6)

Front 4

Triceps brachii

Back 4

O: infraglenoid tubercle of scapula (long head); upper half of posterior surface of humerus (lateral head); distal two-thirds of posterior surface of humerus (medial head)

I: olecranon process of ulna

A: elbow extension; (long head) GH extension, adduction, & horizontal abduction

I: radial n. (C7, C8)

Front 5

Anconeus

Back 5

O: posterior surface of lateral condyle of humerus

I: posterior surface of lateral olecranon process and dorsal surface of ulna

A: elbow extension

I: radial n. (C7, C8)

Hint 5

contracts with triceps

Front 6

Pronator teres

Back 6

O: distal medial condyloid ridge of humerus; medial side of proximal ulna

I: middle third of lateral surface of radius

A: forearm pronation; weak elbow flexion

I: median n. (C6, C7)

Front 7

Pronator quadratus

Back 7

O: distal fourth of anterior side of ulna

I: distal fourth of anterior side of radius

A: forearm pronation

I: median n. (C6, C7)

Hint 7

palmar interosseous branch

Front 8

Supinator

Back 8

O: lateral epicondyle ridge of humerus; dorsal surface of ulna

I: lateral surface of proximal radius (just below the head)

A: forearm supination

I: radial n. (C6)