Lower limb
Lateral plantar nerve
Nervus plantaris lateralis
- Origin
- Smaller terminal division of the tibial nerve within the tarsal tunnel (homologous to the ulnar nerve in the hand)
- Insertion
- Passes obliquely forward with the lateral plantar artery between flexor digitorum brevis and quadratus plantae, dividing into superficial and deep motor branches
- Function
- Motor to quadratus plantae, abductor digiti minimi, all interossei, lumbricals 2–4, adductor hallucis, and flexor digiti minimi; sensory to lateral third of sole and digit 5 plus lateral half of digit 4
- Innervation
- Dominant motor innervation to the intrinsic foot musculature
- Movement & chain
- Controls intrinsic toe spread, metatarsal arch stabilization, and ground adaptation
- Palpation
- Pain reproduction via transverse forefoot compression (Mulder's sign)
- Clinical
- Morton's neuroma (interdigital perineural fibroma classically in the 3rd intermetatarsal space producing sharp burning forefoot pain); Baxter's nerve entrapment (first branch of lateral plantar nerve causing recalcitrant heel pain)
- Segmental innervation
- S1–S2 spinal segments
- In clinical practice
- Mulder's click test; wide-toebox footwear, metatarsal pads, diagnostic ultrasound, and interdigital neuroma excision or decompression
- Region in the model
- Lower limb