- See: Innerv. Musc. Lower Limb
- Plantar muscles of the foot are divided into 4 layers;
- 1st Layer:
- first two layers originate from calcaneal tuberosity and the other two from the metatarsal shafts;
- first subfascial layer consists (from lateral to medial) of the ADM, FDB, & abductor hallucis;
- plantar fascia is comparable to palmar aponeurosis.
- immediately deep to plantar aponeurosis, arising from calcaneus, & sending a tendon to each of lateral 4 toes is FDB, equivalent of FDS of upper limb.
- 2nd Layer:
- muscles of 2nd subfascial layer are (from medial to lateral) tendon of FHL, tendon of FDL, quadratus, & lumbricals
- first two layers originate from the calcaneal tuberosity and the other two from the metatarsal shafts;
- deep to FDL, quadratus, unique to foot, arises from the calcaneus & inserts on the lateral side of tendon of FDL passing obliquely across foot in the same plane.
- 3rd Layer:
- in 3rd subfascial layer are FDM, adductor hallucis, & FHB;
- flexor hallucis brevis splits into medial & lateral tendons, which are inserted into corresponding sides of proximal phalanx of great toe;
- 4th Layer:
- muscles of fourth layer are unipennate plantar & bipennate dorsal interossei, as well as peroneus longus & tibialis posterior;
- lumbricals
Surgical Anatomy of the foot.