TRICEPS
| ORIGIN Long head: infraglenoid tubercle of scapula. lateral head: upper half posterior humerus (linear origin). medial head: lies deep on lower half posterior humerus inferomedial to spiral groove and both intermuscular septa |
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| INSERTION Posterior part of upper surface of olecranon process of ulna and posterior capsule |
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| ACTION Extends elbow. Long head stabilizes shoulder joint. medial head retracts capsule of elbow joint on extension |
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| NERVE Radial nerve (C7, 8) (from posterior cord ), four branches |