ABDUCTOR POLLICIS BREVIS
| ORIGIN Tubercle of scaphoid & flexor retinaculum |
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| INSERTION Radial sesamoid of proximal phalanx of thumb & tendon of extensor pollicis longus |
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| ACTION Abducts thumb at metacarpophalangeal & carpometacarpal joints |
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| NERVE Recurrent (muscular) branch of median nerve(C8, T1) occasionally by ulnar nerve |