1. Plantar Interossei
Origin: Bases and medial sides of metatarsals 3-5
Insertion: Medial sides of bases of 3rd-5th proximal phalanges
Action:
- Adducts digit 2-4
- Flexes metatarsophalangeal joints
Innervation: Lateral plantar nerve (S2/3)

Needling
Position: Prone
Palpation: Palpate between the metatarsals
Technique: Directly perpendicular between the metatarsals
Caution: Low – higher risk of hitting an interdigital nerve

Video 5.1 Needling plantar interossei, original video by Nadine Crocker, CC BY-NC 4.0.