Extensor indicis
From Ganfyd
| Extensor indicis | |
|---|---|
 | |
| System: | Muscle |
| Function: | Extends the metacarpophalangeal joint and interphalangeal joints of the index finger |
| Origin: | Lower part of the posterior shaft of ulna and adjacent interosseous membrane |
| Branches: | |
| Insertion: | Extensor expansion of the index finger |
| Arterial supply: | |
| Venous drainage: | |
| Lymphatic drainage: | |
| Innervation: | Posterior interosseous nerve (C7, C8) |
| Vertebral levels: | |
| Search for Extensor indicis in Gray's. | |
Extensor indicis (extensor indicis proprius) is an extensor of the index finger.
Contents |
Shape
Extensor indicis lies medial to and parallel with extensor pollicis longus. Its tendon passes beneath the extensor retinaculum in the same compartment as the tendons of extensor digitorum. It joins the tendon of extensor digitorum to the index finger over the head of the index metacarpal.
Actions
- Extension of the metacarpophalangeal joint of the index finger
- Extension of the interphalangeal joints of the index finger
Joints Affected
- Metacarpophalangeal joint of the index finger
- Proximal interphalangeal joint of the index finger
- Distal interphalangeal joint of the index finger
Origin
- Lower part of posterior surface of ulna, distal to the origin of extensor pollicis longus
- Adjacent interosseous membrane
Insertion
- Extensor expansion of the index finger via the index finger tendon of extensor digitorum
