Triceps Brachii
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The three-headed elbow extensor (long, medial, lateral heads); the long head also assists shoulder extension.
Detail
The triceps has three heads: (i) long head, (ii) medial head, (iii) lateral head (Thompson, 1989). Functions: (1) extension of the elbow, and (2) assist in extension of the shoulder joint (long head). Origins: long head — lower edge of the glenoid cavity of the scapula; lateral head — upper half of the posterior surface of the humerus; medial head — lower two-thirds of the posterior surface of the humerus. Insertion: olecranon process of the ulna.
Exercises by head: Long head — French press (excellent for the long head) and lying triceps extension (more effective lying on a decline bench with an EZ curl bar). Lateral & medial heads — narrow grip bench press and dumbbell kickbacks. All 3 heads — bench/machine dips and one-arm cable push-down with reverse grip. The triceps is reciprocally innervated to relax during elbow flexion (when biceps brachii, brachialis, brachioradialis contract).
Key facts
- Three heads: long, medial, lateral.
- Functions: elbow extension; long head assists shoulder extension.
- Origins: long head — lower glenoid cavity; lateral head — upper half posterior humerus; medial head — lower two-thirds posterior humerus. Insertion: olecranon process of ulna.
- French press emphasizes the long head; narrow-grip bench/kickbacks the lateral & medial heads; dips and reverse-grip pushdowns all three.
Connections
- Extension — elbow extension.
- Biceps Brachii — antagonist (reciprocal innervation).
- Muscle Action Roles (Agonist, Antagonist, Synergist) — agonist/antagonist relationship.
- French Press / Tricep Pushdowns / Narrow Grip Bench Press — training exercises.
Sources
Exercise guides
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Educational content only — not medical advice. Always consult a qualified professional for individualized guidance, especially around injury, pregnancy, or medical conditions.