Week 13 Anatomy

Arches of the foot.

  •  Medial longitudinal arch
    • Calcaneus, talus, navicular, 3 cuneiforms, 3 metatarsals
    • Talar head is the keystone
    • Tibialis anterior, fibularis longus
  •  Lateral longitudinal arch
    • Calcaneus, cuboid, lateral 2 metatarsals.
  •  Transverse arch
    • Cuboid, cuneiforms, bases of the metatarsals
    • Medial and lateral longitudinal arches form pillars
    • Fibularis longus and tibialis posterior
  • Passive supports
    • Bony congruence/shape
    • KEY: 4 layers of fibrous tissue that bowstring – planta aponeurosis, long plantar ligament, short plantar ligament, spring ligament
  • Active supports
    • Active contraction of intrinsic foot muscles
    • Active contraction of muscles with long tendons coming to foot

 

Layers of the sole

  • 1st : abductor hallucis, flexor digitorum brevis(both medial plantar nerve), abductor digiti minimi(lateral plantar nerve),
  • 2nd Quadratus plantae(lateral plantar- flex toes), lumbricals(lateral 3 lateral plantar), flexor digitorum longus, flexor hallucis longus.
  • 3rd flexor hallucis brevis(medial plantar nerve), adductor hallucis(deep lateral plantar), flexor digitiminimi brevis(superficial lateral plantar)
  • 4th plantar ossei(lateral plantar nerve- adduct and flex at MTP), dorsal interossei(lateral plantar – abduct and flex MTP), fibularis longus tendon, tibialis posterior tendon.

 

Plantar aponeurosis – deep fascia from calcaneus to metatarsals- divided into 3 compartments by intermuscular septa from the skin.

  • Medial compartment – abductor hallucis, flexor hallucis brevis, flexor hallucis longus tendon, medial plantar nerves and vessels
  • Central compartment – plantar aponeurosis, flexor digitorum brevis, flexor hallucis longus and flexor digitorum longus tendons, quadratus plantae, lumbricals, adductor hallucis, lateral plantar nerve and vessels
  • Lateral compartment – abductor and flexor digiti minimi brevis.

 

Blood supply – foot

  • Posterior tibial gives medial and lateral plantar arteries which then reanastamose under metatarsals as deep plantar arch and give digital arteries.
  • Anterior tibial changes to dorsalis pedis which enters the deep plantar arch at 1st webspace.
  • Neurovascular planes
  • Superficial – between 1st and 2nd muscle layers – medial plantar nerve, lateral plantar nerve and artery
  • Deep – between 3rd and 4th

 

Sustenaculum Tali

  • On calcaneous
  • Gives attachment to the plantar calcaneo-navicular (spring) ligament, tibiocalcaneal ligament, and medial talocalcaneal ligament. This eminence is concave above, and articulates with the middle calcaneal articular surface of the talus; below, it is grooved for the tendon of the Flexor hallucis longus;