Skip to main content

Unfortunately we don't fully support your browser. If you have the option to, please upgrade to a newer version or use Mozilla Firefox, Microsoft Edge, Google Chrome, or Safari 14 or newer. If you are unable to, and need support, please send us your feedback.

Elsevier
Publish with us
Third Palmar Interosseous Muscle
Muscular System

Third Palmar Interosseous Muscle

Musculus interosseus palmaris tertius

Read more

Quick Facts

Origin: Palmar aspect of fifth metacarpal bone.

Insertion: Lateral aspect of base of proximal phalanx and extensor expansion of little finger.

Action: Adducts little finger at its metacarpophalangeal joint; simultaneously flexes metacarpophalangeal joint and extends interphalangeal joints of little finger.

Innervation: Deep branch of ulnar nerve (C8-T1).

Arterial Supply: Deep palmar arch, perforating branches of deep palmar arch, palmar metacarpal and common palmar digital arteries.

Complete Anatomy
The world's most advanced 3D anatomy platform
Try it for Free

Origin

The third palmar interosseous muscle originates from the palmar aspect of fifth metacarpal bone.

Insertion

The fibers of the third palmar interosseous muscle travel inferiorly to the little finger and insert, via a short tendon, onto the:

- lateral aspect of the base of the proximal phalanx of little finger;

- extensor expansion of little finger.

Key Features & Anatomical Relations

The third palmar interosseous muscle is found in the interosseous compartment of the hand. It is a short, unipennate skeletal muscle. It is located:

- anterior to the fifth metacarpal bone and the fourth dorsal interosseous muscle of hand;

- posterior to the fourth lumbrical muscle of hand.

Actions & Testing

The third palmar interosseous muscle is involved in multiple actions:

- adducts the proximal phalanx of little finger (i.e., draws it towards the longitudinal axial line of the middle finger) at the fifth metacarpophalangeal joint;

- simultaneously flexes the fifth metacarpophalangeal joint and extends the interphalangeal joints of the little finger, which occurs when the fourth lumbrical muscle of hand contracts simultaneously with it.

The third palmar interosseous muscle can be tested by adducting the proximal phalanx of little finger at the fifth metacarpophalangeal joint against resistance (Standring, 2016).

References

Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.

Learn more about this topic from other Elsevier products

Hand Muscle

ScienceDirect image

When hand muscles contract shortly after individuals engage in a repetitive action that forms the basis of their livelihood, neurologists term the disorder occupational dystonia or task-specific dystonia.

Explore on ScienceDirectopens in new tab/window

Complete Anatomy

The world's most advanced 3D anatomy platform

Complete Anatomy