2. Lumbricals

Origin: The tendons of flexor digitorum profundus

Insertion: Extensor expansion near the metacarpophalangeal joint

Action: Flexion of the metacarpophalangeal and extension of the interphalangeal joints

Innervation:

  • First two lumbricals – Median nerve (C8/T1)
  • Third and fourth lumbricals – Ulnar nerve (C8/T1)
Lumbricals.
Figure 11.4 Lumbricals, adapted by Uwe Gille from the original image by Henry Gray and Henry Vandyke Carter (Public domain).

Needling

Position: Various (supine/prone or sitting) with arm supinated

Palpation: Palpate between the metacarpals

Technique: Needle between the metacarpals approximately ½-1 cun deep

Caution: Low – interdigital nerves are vulnerable when needling these muscles

Needling lumbricals.
Figure 11.5 Needling lumbricals, original image by Nadine Crocker, CC BY-NC 4.0.

Video 11.2 Needling lumbricals, original video by Nadine Crocker, CC BY-NC 4.0.

License

Icon for the Creative Commons Attribution-NonCommercial 4.0 International License

Sinew Channel Needling Copyright © 2026 by Nadine Crocker is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License, except where otherwise noted.