Extensor Indicis Muscle
Table of Contents
Extensor Indicis Muscle Anatomy
Extensor indicis is a narrow, elongated muscle found in the posterior compartment of the forearm. It belongs to the deep extensors of the forearm. Together with supinator, abductor pollicis longus, extensor pollicis longus, and extensor pollicis brevis muscles, it causes the extension of the wrist and fingers. It can be palpated by applying deep pressure over the lower part of the ulna while the index finger is extended.
Origin :
It originates from the posterior surface of distal third of ulna and interosseous membrane.
Insertion :
It inserts into the extensor expansion of index finger .
Nerve supply :
The posterior interosseous nerve innervates the muscle.
Blood supply :
The posterior interosseous and anterior interosseous artery supplies the muscle.
Action :
It extends the index finger at the metacarpophalangeal joint.
Function :
Extensor indicis acts at the metacarpophalangeal and interphalangeal joints to extend the index finger. Unlike most of the other fingers of the hand, the index finger has its own separate extensor, which enables it to extend independently from other fingers. In addition, as it crosses the wrist, this muscle produces a weak extension of this joint.
Strengthening exercise:
Resisted Isometric Finger Extension :
- Start in a seated position
- Place your affected arm on a table with your palm facing down and fingers flat on the table.
- Use your thumb or the table to hold your middle, ring and little fingers bent, keeping your index finger straight.
- Use your opposite hand to resist the index finger from lifting towards the ceiling.
- Try to keep your forearm and wrist on the table throughout the exercise.
- Repeat this exercise for 5-10 times.
Stretching exercise :
Forearm extensor stretch
1 Place your affected elbow down at your side, bent at about 90 degrees. Then make a fist with your palm facing down.
2 Keeping your wrist bent, slowly straighten your elbow so your arm is down at your side. …
3 Hold for at least 15 to 30 seconds.
4 Repeat 2 to 4 times.
Related pathology :
The most common condition affecting Extensor Indicis Propius is Tenosynovitis.
For more hand muscle related post :
