Extensor digiti minimi (EDM) muscle

Extensor digiti minimi (EDM) muscle is a muscle of the superficial layer of the posterior compartment of the forearm, and with other extensor muscles arises from a common extensor tendon attached to the lateral epicondyle of the humerus. The EDM represents a medial group of superficial extensor muscles. The EDM passes under the extensor retinaculum near the wrist and passes through the 5extensor compartment of the wrist. It is one of the extrinsic muscles of the hand.

Summary

• origin: lateral epicondyle of humerus
• insertion: tendon of extensor digitorum muscle for the 5 digit
• arterial supply: radial recurrent artery, posterior interosseous artery
• innervation: posterior interosseous nerve (C7 and C8), a continuation of the deep branch of the radial nerve (C7, C8)
• action: extension in metacarpophalangeal joint and wrist joint