The extensor digiti minimi is a superficial muscle which lies on the posterior (dorsal) aspect of forearm. It is long, thin, and spindle-shaped, being located directly under the skin. It arises from the lateral epicondyle of humerus, the lateral ligament of elbow, and the antebrachial fascia. Then it stretches downwards and slightly obliquely, switching over to the ulnar aspect of forearm (little finger side).
In the distal portion of ulna, it becomes a tendon, which gets lodged in the synovial sheath of the extensor digiti minimi tendon. Once it has left this sheath, it joins the extensor digitorum tendon to be inserted into the base of the distal phalanx of little finger.
Action/Function
It extends the little finger.
Innervation
It is supplied by the radial nerve (C5-C6-C7-C8).
Blood Supply
The extensor digiti minimi muscle gets oxygenated blood from branches of the posterior interosseous artery, which arises from the common interosseous.
Below, superficial muscles of posterior compartment of right forearm, with the extensor digiti minimi clearly labeled.