Triceps

Description

Posterior male upper trunk and arms are rendered with the triceps brachii emphasized bilaterally across the posterior compartment of the arm. Proximally, the long head arises from the infraglenoid tubercle of the scapula, running inferior to the posterior deltoid and forming the medial border of the posterior axillary fold alongside teres major and latissimus dorsi. Lateral and medial heads originate from the posterior humerus (straddling the radial groove) and converge distally into a common triceps tendon inserting on the olecranon of the ulna, positioned posterior to the elbow joint and superficial to the anconeus. Fiber direction and muscle belly contour make the posterior arm volume obvious. Clear separation from the more lateral brachioradialis and posterior forearm extensors helps with orientation. Elbow extension is the headline function, but the long head also contributes to shoulder extension and adduction, so this view helps when teaching why push-ups, dips, and overhead activities load different portions of the muscle. Clinically, the relationships matter: the radial nerve and profunda brachii artery course in the spiral (radial) groove deep to the lateral head, so midshaft humeral fractures or posterior humeral plating can produce wrist drop and posterior arm sensory loss. Distally, appreciating the triceps tendon footprint on the olecranon supports discussions of partial tendon rupture after a fall on an outstretched hand and of posterior elbow approaches that split the tendon or reflect it as part of an olecranon osteotomy. Good landmarks. No guesswork. Use this asset in gross anatomy or kinesiology modules on the posterior compartment of the arm, in orthopedic and sports medicine texts covering humeral shaft trauma and triceps tendon injury, and in rehabilitation materials that cue elbow extension strength testing and progressive loading. Anatomical accuracy verified by SciePro's Medical Advisory Board.