Dorsal Interossei

Introduction

Dorsal interossei

Cross section of hand shows the dorsal and palmer interosseous muscles

General

• Four muscles
• Located on the dorsum of the hand

Origin

• Interosseous muscle I
  • Adjacent surfaces of 1st and 2nd metacarpals
• Interosseous muscle II
  • Adjacent surfaces of 2nd and 3rd metacarpals
• Interosseous muscle III
  • Adjacent surfaces of 3rd and 4th metacarpals
• Interosseous muscle IV
  • Adjacent surfaces of 4th and 5th metacarpals

Insertion

• Interosseous muscle I
  • Radial aspect of base of proximal phalanx of digit 2
• Interosseous muscle II
  • Radial aspect of base of proximal phalanx of digit 3
• Interosseous muscle III
  • Ulnar aspect of base of proximal phalanx of digit 3
• Interosseous muscle IV
  • Ulnar aspect of base of proximal phalanx of digit 4

Actions

• Interosseous muscle I
  • Radial abduction of digit 2
• Interosseous muscle II
  • Radial abduction of digit 3
• Interosseous muscle III
  • Ulnar abduction of digit 3
• Interosseous muscle IV
  • Ulnar abduction of digit 4
• Assist in flexion of the metacarpophalangeal joints
• Assist in extension of the proximal and distal interphalangeal joints

Vascular Supply

• Anterior and Posterior Digital Arteries

Nerve

• Ulnar Nerve (Deep Branch, C8-T1)

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Clinical Significance

• Ulnar Claw

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See Also

• Physical Exam Hand
• Hand And Wrist Anatomy
• Hand Pain (Main)
• Wrist Pain (Main)

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