Plantar Surface of Foot

• Bones of the Foot

  
• Deep Fascia & Plantar Aponeurosis

  Deep Fascia:

  Thick central portion

  Weaker medially and laterally

  Plantar Aponeurosis:

  Superficial Ligament formed by central portion of deep fascia

  Proximal attachment to Calcaneus

  Divides into 5 bands distally – continuous  with fibrous digital sheaths

  Vertical intermuscular septae:

  Medial, Central and Lateral compartments

  
• Compartments of the Foot

  Muscles of Dorsum of Foot: Extensor Digitorum Brevis, Extensor Hallucis Brevis

  Lateral Compartment: Muscles of the little toe:

  Abductor Digiti Minimi, Flexor Digiti Minimi Brevis

  Central Compartment: Flexor Digitorum Brevis, Muscles associated with tendon of FDL (lumbricals and quadratus plantae), Adductor Hallucis

  Medial Compartment: Muscles of the great toe: Abductor Hallucis , Flexor Hallucis Brevis

  Interossei: Plantar and Dorsal interossei

  
• Foot – Layer 1

  Abductor Hallucis (1)

  Medial Tubercle of Calcaneus;  Flex. Retinaculum

  → Med. Base proximal Phalanx

  Flexor Digitorum Brevis (2)

  Medial Tubercle of Calcaneus

  → Middle Phalanges of lateral 4 toes

  Abductor Digiti Minimi (3)

  Med. and Lat. Tubercle of Calcaneus      

  → Lat. Base proximal Phalanx

  
• Layer 1

  
• Foot – Layer 2

  Long flexor tendons to the toes:

  FDL and FHL

  Lumbricals *

  Tendons of FDL

  → Med. side of dorsal tendon expansion

  Quadratus Plantae (QP)

  Med. and Lat. surfaces of Calcaneus

  → Lateral side of FDL tendon

  
• Layer 2

  
• Layers 1 & 2

  
• Foot – Layer 3

  Flexor Hallucis Brevis

  Cuboid and Lat. Cuneiform

  → Both sides base Proximal Phalanx of Hallux

  Adductor Hallucis

  Transverse head: Plantar ligament of MTPJoints

  Oblique head: Base metatarsals 2-4

  → Lat. side base Proximal Phalanx of Hallux

  Flexor Digiti Minimi Brevis*

  Base 5th Metatarsal

  → Base Proximal Phalanx of 5th digit

  
• Layer 3

  
• Foot – Layer 4

  Interossei

  3x Plantar Interossei

  Bases and Med. side of Metatarsals 3-5 (unipennate)

  → Med. side of proximal phalanx of 3rd -5th digit

  PAD – Plantar ADduct

  4x Dorsal Interossei

  Adjacent sides of Metatarsals 1-5 (bipennate)

  → 1st on med. side proximal phalanx of 2nd digit

  →2nd-4th on lat. side proximal phalanx of 2nd -4th digits

  DAB – Dorsal ABduct

  N.B. 2nd toe is axial digit of foot

  
• Layer 4

  Tendons:

  -Peroneus Longus *

  -Tibialis Posterior (TP)

  
• Layers 3&4

  
• Plantar Nerves

  Terminal branches of Tibial nerve deep to flexor retinaculum

  Enter foot deep to Abductor Hallucis

  Medial Plantar Nerve:

  Between Abductor Hallucis and FDB

  Lateral Plantar Nerve:

  Between Layers 1&2

  Deep and Superficial branches

  Deep branch between Layers 3&4

  
• Innervation of Muscles of Foot

  Medial Plantar Nerve:

  Abductor Hallucis

  Flexor digitorum brevis

  1st Lumbrical

  Flexor hallucis brevis

  Lateral Plantar Nerve:

  All other muscles

  S2, 3

  
• Cutaneous Innervation of the Foot

  
• Plantar Arteries

  -Terminal branches of Posterior Tibial artery deep to flexor retinaculum

  -Enter foot deep to Abductor Hallucis

  Medial Plantar artery:

  -Muscles of hallux and overlying skin

  -Occassionally: Superficial Plantar Arch

  Lateral Plantar artery:

  -Initially between Layers 1 and 2

  -Deep Plantar Arch between Layers 3 and 4

  -Deep Plantar a. from Dorsalis Pedis

  -Plantar Metatarsal and Digital aa.

  
• Plantar Arteries