Muscle
Extensor digiti minimi
Additional little-finger extensor
High-yield
Wrist compartment 5 contains the extensor digiti minimi tendon. Its separate muscle belly helps the little finger extend independently.
Overview
This slender muscle gives the little finger a separate route for extension alongside extensor digitorum. Its tendon enters the finger's extensor expansion.
Reference facts
- Origin
- Common extensor origin at the lateral epicondyle of the humerus
- Insertion
- Extensor expansion on the dorsal side of the little finger
- Action
- Extends the little finger, especially its MCP joint; assists extension through its extensor expansion
- Innervation
- Posterior interosseous nerve, commonly C7-C8
- Blood supply
- Posterior interosseous arterial branches
Clinical correlation
Arthritis around the distal radioulnar joint can damage nearby extensor tendons. Rupture may begin with the little-finger extensors and progress toward the radial fingers, a pattern called Vaughan-Jackson syndrome.
Frequently asked questions
What does the extensor digiti minimi do?
Extends the little finger, especially its MCP joint; assists extension through its extensor expansion.
What nerve innervates the extensor digiti minimi?
Posterior interosseous nerve, commonly C7-C8.
Where does the extensor digiti minimi attach?
The extensor digiti minimi originates from the common extensor origin at the lateral epicondyle of the humerus and inserts on the extensor expansion on the dorsal side of the little finger.
What is the blood supply of the extensor digiti minimi?
Posterior interosseous arterial branches.