Third palmar interosseous muscle
Musculus interosseus palmaris tertius
- Related terms: Palmar interossei (3)
Definition
Third palmar interosseous muscle | |||
Origin | From the lateral side of the palmar surface of the fifth metacarpal bone (little finger) | ||
Insertion | Proximal phalanx and extensor hood (extensor expansion) of the 5th digit (little finger) | ||
Innervation | Deep branch of the ulnar nerve (C8, T1) | ||
Action | Adduction of the little finger | ||
The third palmar interosseous muscle arises from the radial side of the fifth metacarpal bone. It inserts into the radial side of the base of the proximal phalanx of the little finger and its extensor hood, enabling adduction of the little finger towards the middle finger.
The palmar interossei also assist in flexion at the metacarpophalangeal joints and extension at the interphalangeal joints via their insertion into the extensor expansion.
References
Valenzuela M, Bordoni B. Anatomy, Shoulder and Upper Limb, Hand Palmar Interosseous Muscle. [Updated 2025 Apr 27]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537165/
