ABDUCTOR POLLICIS LONGUS
| ORIGIN Upper posterior surface of ulna and middle third of posterior surface of radius and interosseous membrane between |
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| INSERTION Over tendons of radial extensors and brachioradialis to base of 1st metacarpal and trapezium |
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| ACTION Abducts and extends thumb at carpometacarpal joint |
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| NERVE Posterior interosseous nerve (C6, 7) |