4. Triceps Brachii

Origin:

• Long head: Infraglenoid tubercle of the scapula
• Lateral head: Posterior aspect of the humerus just above the radial groove
• Medial head: Posterior aspect of the humerus just below the radial groove

Insertion: Olecranon process of the ulna

Action:

• Extends the forearm
• Extends the humerus
• Long head – assists in adduction of the humerus

Innervation: Radial nerve (C6/7/8) innervates all portions of the triceps

Note: Variation does exist and in some cases, the medial head gets innervation from the ulnar nerve and the long head by the axillary nerve

Needling

Position: Variable – prone, supine, side-lying

Palpation: Hard to miss, just inferior to the deltoid on the posterior aspect of the humerus

Technique: Grasp the muscle and needle medial to lateral (or vice versa) threading through the muscle belly

Caution: Low – caution of the ulna nerve when targeting the medial head of the triceps – caution of the radial nerve between the long and medial head of the triceps