1st Palmar Interossei of the Hand

Parent Structures

• Intrinsic Hand Muscles

Proximal/Superior Attachment

• Shaft of 1st Metacarpal - Medial Side

Distal/Inferior Attachment

• Base of Proximal Phalanx of the Thumb - Dorsal Digital Expansion

Joint Actions

• Agonist
  • 1st Metacarpophalangeal Joint (1st MCP)
    • Flexion

Nerve Innervation

• Ulnar Nerve