Hand Lumbricals

• Lumbricals:

  • 4 small muscles in palm of hand (associated with tendons of flexor digitorum profundus)

  
• Lateral 2 and Medial 2 lumbricals both:

  • insert into lateral aspect of DDE on the base of proximal phalanx
  • action = flexion at MCP joint and extension at IP joint
• • lateral 2 lumbricals: unipennate, originate at lateral aspect of lateral flexor digitorum profundus tendon (2nd & 3rd digit), NS is medial nerve
  • medial 2 lumbricals: bipennate, originate at adjacent aspect of flexor digitorum profundus tendon, NS is deep branch of ulnar nerve