Palmar Interossei

Original Editor -Dr.Neha Duhan(PT)

Top Contributors - Neha Duhan, Chelsea Mclene, Kim Jackson and Rishika Babburu

Description

The palmar interossei or volar are three short, unipennate muscles on the palmar surface of the hand and along with the dorsal interossei muscles. These occupy the spaces between the metacarpal bones. These are attached to the index, ring, and little fingers. They are smaller than the dorsal interossei of the hand. Palmar interossei muscles are strong Adductors of Fingers and assists in flexion of the metacarpophalangeal joints and extension of the interphalangeal joints.

Origin

• The first palmar interossei also known as pollical palmar interosseous and it originates at the media palmar surface of the first metacarpal. It is often considered as rudimentary.
• The second palmar interosseous originates at the medial surface of the base of the second metacarpal.
• The third and fourth palmar interossei originate at the lateral aspect of the fourth and fifth metacarpals.

Insertion

• The 1st interossei inserts into the base of the proximal first phalanx
• The 2nd inserts onto the medial portion of the extensor hood of the first digit as well as the base of the first phalanx.
• The 3rd and 4th interossei inserts into the lateral aspect of their respective extensor hood.

Nerve

The palmar interossei receive nerve supply from the deep branch of the ulnar nerve. The deep branch of the ulnar nerve arises from nerve roots of C8 and T1.

Artery

Palmar interossei muscles receive arterial blood supply from the palmar metacarpal arteries and drains into the palmar metacarpal veins. The palmar metacarpal arteries derive from the deep palmar arch, which is comprised of the terminal portion of the radial artery and the deep branch of the ulnar artery.