Foot Flashcards
Bones of foot
Calcaneus Talus Navicular Cuneiform (x3) Cuboid 5 metatarsals 14 phalanges (2 on hallux, 3 on digits)
Deep fascia of foot
Dorsum of foot-thin and continuous with extensor retinaculum
Sole of foot-plantar fascia
Central part thickens to form plantar aponeurosis
Plantar aponeurosis
Central thickened part of plantar fascia
Consists of longitudinally arranged band of dense CT
Arises from calcaneus posteriorly
Converse entire length of sole
Divides into 5 bands
Passive support for arch of foot (longitudinal arch)
Plantar fasciitis
Plantar aponeurosis inflammation at calcaneus
Pain most severe after sitting and getting out of bed
Running, high-impact exercise, worn-out shoes, overweight
May lead to bony process-“heel spur”-especially from medial calcaneal tubercle
Dorsal foot muscles
Extensor hallucis brevis (1st phalanx)
Extensor digitorum brevis (2nd-4th phalanges)
N: lateral branch of deep fibular N.
Forms a fleshy mass on lateral part of dorsum of foot anterior to lateral malleolus
A: extends toes
Plantar muscles
4 layers
Help maintain foot arches
Stand on uneven ground
Plantar muscle: first layer
Abductor digiti minimi
Flexor digitorum brevis
Abductor hallucis
Plantar muscles: second layer
Quadratus plantae: joins tendon of FDL to calcaneus; assists FDL in flexing lateral four digits
Lumbricals: originate from flexor digitorum longus tendons
Medial aspect of extensor expansion
A: flex MP join, extend PIP and DIP joints
Tendons on second layer
Flexor hallucis longus
Flexor digitorum longus
Plantar muscles: third layer
3 short muscles to first and fifth digits
Flexor digiti minimi brevis
Adductor hallucis: Transverse and oblique head
Flexor hallucis brevis: medial and lateral head cover plantar surface of first metatarsal
Tendons have sesamoid bones that rote to first metatarsal head and tendon of FHL when standing and walking
Opponens digit minimi: not actually a muscle
Plantar Muscles: fourth layer
3 plantar interossei: digits 3,4, and 5 toward 2nd digit
4 dorsal interossei: digits 2,3, and 4 way from midline of digit 2
Tendons found on fourth layer
Fibularis longus and tibialis posterior
Hallux valgus
Foot deformity characterized by lateral deviation of great toe
Surrounding tissues swell and resultant pressure and friction against the shoe cause a bursa to form
Tender and inflamed bursa-bunion
Corns-inflamed areas of thick skin; form over proximal interphalangeal joints
Mallet toe
Flexion in the distal IP joint
Hammer toe
“Hammer like” deformity (usually of 2nd digit)
Proximal phalanx is permanently hyperextended at MP joint
Middle phalanx is plantarflexed at PIP joint
Distal phalanx is extended
Claw toe
Hypertension of MP joints
Flexion of distal and proximal IP joints
Trigger toe
When deformity occurs in the large toe
Extended MP, flexed IP
What causes toe deformities?
Shortened flexor muscles which can override lumbrical function
Nerves on sole of foot
Tibial N. Divides posterior to medial malleolus into
Medial and lateral plantar Ns.
Supply all intrinsic muscles of foot (except two intrinsic dorsum muscles)
Supply plantar skin
Medial plantar N.
Larger of the two branches
Passes deep to abductor hallucis
Runs anteriorly between abductor hallucis and flexor digitorum brevis
Terminates near metatarsal bases by dividing into four sensory branches
Supply medial 3 and a half digits
Lateral Plantar N.
Smaller of the two branches
Passes deep to abductor hallucis
Runs anterolaterally deep to flexor digitorum brevis
Terminates by dividing into superficial and deep branches
Medial plantar N. Innervations
Abductor hallucis
Flexor digitorum brevis
Medial 1 lumbrical
Flexor hallucis brevis
Lateral plantar N. Innervations
Abductor digiti minimi Quadratus plantae Lateral 3 lumbricals Adductor hallucis Flexor digiti minimi brevis Interossei
Foot blood supply
Terminal branches of anterior and posterior tibial arteries Lateral malleolar A. Lateral tarsal A. Dorsalis pedis A. Arcuate artery Deep plantar A.
Dorsalis pedis branches
Arcuate A.
Deep plantar A.
Arcuate A.
Branch of dorsalis pedis A.
Runs laterally across metatarsal bases (deep to extensor tendons)
Gives rise to 2nd-5th dorsal metatarsal As.
Those give rise to Dorsal digital As.
Deep plantar A.
Branch of dorsalis pedis A.
Passes through first interosseous space
Joins lateral plantar A. To form the plantar arch
Gives rise to first dorsal metatarsal A.
Blood supply of plantar aspect of foot
Derived from posterior tibial A.
Divides deep to abductor hallucis
Medial and lateral plantar As.
Medial plantar A.
Passes distally between abductor hallucis and flexor digitorum brevis
Gives rise to media two plantar metatarsal and plantar digital arteries
Lateral plantar A.
Runs with lateral plantar N. (Superficial to quadratus plantae)
Terminates by lining deep plantar A. Forming plantar arterial arch
Gives rise to 3rd-6th plantar metatarsal and plantar digital As.
Foot arches
Formed by tarsal and metatarsal bones Absorbs shock during weight bearing Makes foot adaptable to surface and weight changes Longitudinal arch Transverse arch
Longitudinal arch
Medial and lateral parts
Medial: calcaneus, talus, navicular, three cuneiforms, and medial three metatarsals
Lateral: calcaneus, cuboid, and lateral two metatarsals
Transverse arch
Runs between medial and lateral longitudinal arches
Formed by cuboid, three cuneiforms, and metatarsal bones
Ankle (talocrural) joint
Tibia and fibula and talus
Hinge synovial
Three-sided deep socket formed by two malleoli and inferior tibia
Malleoli grip on trochlea strongest during dorsiflexion
Articular capsule
Foot joints
Many involve tarsus, metatarsus, and phalanges
Only slight movement between them
Transverse tarsal joint
Subtalar joint
Transverse tarsal joint
Two separate joints aligned transversely
Calcaneocuboid joint
Talonavicular joint
Working together permit slight rotation and this add to inversion and eversion at this joint
Transaction across this joint is standard method for surgical amputation of foot
Subtalar joint
Talocalcanean joint
Where talus rests on calcaneus
Inversion and eversion
Fibrous capsule supported by interosseous talocalcaneal L.
