2. Lumbricals
Origin: Tendons of the flexor digitorum longus
Insertion: Medial aspect of expansion over digit 2-5
Action:
- Flex proximal phalanges 2-5
- Extends middle and distal phalanges 2-5
Innervation:
- Medial one: Medial plantar nerve (S2/3)
- Lateral three: Lateral plantar nerve (S2/3)

Needling
Position: Prone
Palpation: Palpate the tendons of flexor digitorum longus
Technique: Needle just lateral to the tendons (same technique as for interossei)
Caution: Low – higher risk of hitting an interdigital nerve

Video 5.2 Needling lumbricals, original video by Nadine Crocker, CC BY-NC 4.0.