Corpus: Extensor digiti minimi muscle
Definition
The extensor digiti minimi muscle is a slender muscle that belongs to the superficial layer of the extensor muscles of the forearm. Functionally, it is part of the extensor digitorum muscle but has a separate tendon and runs in its own tendon compartment, making it considered separately.
Anatomy
Origin
The extensor digiti minimi muscle originates from the lateral epicondyle of the humerus, medial to the extensor digitorum muscle. Additionally, it has origin surfaces on the septa that separate it from adjacent muscles.
Insertion
The muscle runs approximately in the center on the dorsal side of the forearm and ends in a flat tendon, which extends towards the wrist. This tendon, under the extensor retinaculum and within its own tendon sheath, reaches the back of the hand and attaches at the base of the 5th finger. There, it merges with the dorsal aponeurosis of the 5th finger, attaching to its middle and distal phalanges (Phalanx media et distalis).
Innervation
The innervation of the extensor digiti minimi muscle is provided by the deep branch of the radial nerve, with fibers from segments C6 to C8.
Function
The extensor digiti minimi muscle is responsible for extending the 5th finger (Digit V). Additionally, it aids in ulnar abduction at the wrist.