Muscles of the Elbow and Forearm

Brachioradialis

Originates on the lateral supracondylar ridge on the humerus and inserts on the styloid process of the radius. It is effective in elbow flexion.

Brachialis muscle

Sometimes called the "workhorse" of the elbow joint. This muscle has no attachment to the radius, therefore no role in supination and pronation. It originates at the distal half of the humerus on the anterior surface and inserts on the coronoid process and ulnar tuberosity of the ulna. Action is elbow flexion.

Prime movers in elbow extension

Triceps

Triceps brachii

Commonly called the "triceps" derives its name from its three heads. The long head attaches at the infraglenoid tubercle of the scapula, the lateral head, inferior to the greater tubercle on the posterior humerus, and the medial head at the posterior surface of the humerus. It inserts at the olecranon process of the ulna and is effective in elbow extension.

Pronator teres

Gets its name partially from its action of pronation of the forearm. It originates at the medial epicondyle of the humerus and coronoid process of the ulna. It inserts at the lateral aspect of the radius at its midpoint. It is also assistive in elbow flexion.

Biceps Brachii

Has two heads and is located on the arm and is most commonly referred to as the biceps. The long head originates on the supraglenoid tubercle of the scapula and the short head originates at the coracoid process of scapula. It inserts at the radial tuberosity of the radius. Actions include elbow flexion and forearm supination.

Supinator

A deep muscle that wraps around the elbow joint laterally from the posterior surface to the anterior surface. It originates at the lateral epicondyle of the humerus and adjacent ulna and inserts on the anterior surface of the proximal radius. Its action is forearm supination.

Anconeus

A small muscle that originates on the lateral epicondyle of the humerus and inserts lateral and inferior to the olecranon process of ulna. It is not a prime mover in any joint action but assists in elbow extension.

Pronator quadratus

Also gets it name from its action of pronation of the forearm. It originates at the distal 1/4 of the ulna and inserts at the distal 1/4 of the radius.

Prime movers in elbow flexion

Biceps, Brachialis, and Brachioradialis

Prime movers in forearm supination

Biceps, Supinator

Prime movers in forearm pronation

Pronator teres and Pronator quadratus