98 Abductor pollicis longus
![](img/model2/no_98forearm.png)
Origin:
Posterior surface of proximal halves of ulna, radius, and interosseous membrane
Insertion:
Base of 1st metacarpal
Blood Supply:
Posterior interosseous artery
Innervation:
Posterior interosseous nerve (C7, C8), continuation of deep branch of radial nerve
Main Action:
Abducts thumb and extends it at carpometacarpal joint