Muscle Function: Extends the elbow. Long head assists in adduction and extension of the shoulder.
Palpation: Long, medial and lateral muscle bellies can be individually palpated on the posterior arm. Palpate just proximal to the olecranon.
Gravity-lessened Test: Position ““ patient seated or supine with shoulder and elbow flexed to 90º. Stabilize ““ forearm and hand to eliminate effect of gravity. Resist ““ extension of the elbow (in the direction of elbow flexion).
Alternate Gravity-lessened Test: Position ““ patient seated with shoulder abducted to 90º; elbow flexed to 90º. Stabilize ““ arm on a table close to shoulder height. Patient extends elbow by sliding forearm on the table. Resist ““ extension of the elbow (in the direction of elbow flexion).
Possible Substitutions: No true substitutions. Careful not to let effect of gravity give illusion of active elbow extension.
Origin of Long Head: Infraglenoid tubercle of the scapula.
Origin of Lateral Head: Lateral and posterior surface of the proximal ½ of the humerus and the lateral intermuscular septum.
Origin of Medial Head: Distal â…” of the medial and posterior surface of the humus below the radial groove and intermuscular septum.
Insertion: Posterior surface of the olecranon process of the ulna and the antebrachial fascia.
Origin: Posterior surface of lateral epicondyle of humerus.
Insertion: Lateral side of olecranon process and superior ¼ of posterior surface of ulna.