Proximal attachment of short head: Apex of coracoid process of scapula. (Located on the medial aspect of the anterior surface of the upper arm.)

Proximal attachment of long head: Through the intertubercular groove, to the supraglenoid tubercle on the superior aspect of the glenoid fossa of the scapula. (Located on the lateral aspect of the anterior surface of the upper arm.)

Distal attachment: Radial tuberosity and bicipital aponeurosis.

Action: Flexes the elbow joint moving the forearm toward the humerus, and supinates the forearm.

In addition, the long head assists in flexing the shoulder joint, and may assist with abduction if the humerus is externally rotated.

Nerve: Musculocutaneous.

Proximal attachment: Distal one-half of anterior surface of humerus.

Distal attachment: Coronoid process of ulna.

Action: Flexes the elbow joint.

Nerve: Musculocutaneous.

Proximal attachment: Distal two-thirds of lateral supracondylar ridge of humerus.

Distal attachment: Lateral side of base of styloid process of radius.

Action: Flexes the elbow joint, and assists in pronating and supinating the forearm.

Nerve: Radial.

Proximal attachment of long head: Infraglenoid tubercle on the inferior surface of the glenoid fossa of the scapula. (Located proximally on the medial aspect of the posterior surface of the upper arm.)

Proximal attachment of lateral head: Lateral and posterior surfaces of proximal one-half of the body of the humerus. (Located on the lateral aspect of the posterior surface of the upper arm.)

Proximal attachment of medial head: Distal two-thirds of medial and posterior surfaces of humerus. (Located distally on the medial aspect of the posterior surface of the upper arm.)

Distal attachment: Olecranon process of ulna.

Action: Extends the elbow joint.

In addition, the long head assists in adduction and extension of the shoulder joint.

Nerve: Radial.

Proximal attachment: Lateral condyle of humerus, posterior surface.

Distal attachment: Posterior, lateral aspect of olecranon process.

Action: Extends the elbow joint.

Nerve: Radial.

FOREARM

Proximal attachment of humeral head: Immediately above medial epicondyle of humerus (distal aspect, medial supracondylar ridge).

Proximal attachment of ulnar head: Medial side of coronoid process of ulna.

Distal attachment: Middle third of lateral surface of radius.

Action: Pronates the forearm and assists in flexing the elbow joint.

Nerve: Median.

Medial attachment: Anterior surface of distal one-fourth of ulna.

Lateral attachment: Anterior surface of distal one-fourth of radius.

Action: Pronates the forearm.

Nerve: Median.

Proximal attachment: Lateral epicondyle of humerus, supinator crest on the proximal posteriolateral aspect of the ulna and the ligaments of the lateral elbow joint (radial or lateral collateral ligament and the annular ligament).

Distal attachment: Lateral surface of proximal one-third of body of radius covering part of the anterior, lateral and posterior surfaces.

Action: Supinates the forearm.

Nerve: Radial.