16. anatomy of the leg and foot Flashcards
Function of the foot?
Supporting body weight
Stability/standing
Locomotion/propulsion (lever)
Shock absorption
Bones of the leg
Fibula and tibia Lateral and medial condyles Superiro tibifibular joint Tibial tuberosity Interosseus membrane Lateral malleolus on fibula medial malleolus on tibia inferior tibiofibular joint
joints between fibula and tibia
superior tibiofibular joint
inferior tibiofibular joint
Bones of the foot
Tarsals: Calcaneus Talus cuboid Navicular Cuneiforms
Metatarsals
Phalanges
features of posterior of foot
calcaneal tuberosity (heel) sustentaculum tali (extension of calcaneus over talus) Sesmoid bones under D1 metatarsal
Movements of the foot
Dorsiflexion/extension
Plantarflexion/flexion
Eversion
Inversion
Supination (feet together - inversion/adduction)
Pronation (feet apart - eversion/abduction of front of foot)
Joints of the foot
Ankle joint - dorsiflexion/plantarflexion
Intertarsal joints (e.g. subtalar and transverse tarsal) - invert/evert, supinate
Metatarsophalangeal joints - extension/flexion, limited abduction/adduction
Interphalangeal . joints - extension and flexion
Ankle joint
extension/flexion
Intertarsal joint
Invert/evert
Supinate/pronate
metatarsophalangeal joints
extension/flexion
limited abduction/adduction
interphalangeal joints
extension/flexion
Ankle
articulation between talus and tibia/fibula
synovial hinge joint
What structures stabilise the ankle?
The lateral ligament - lateral malleolus to talus/calcaneus
Medial/deltoid ligament - medial malleolus to talus/calcaneus/navicular
Clinical implication of lateral/medial ligaments of ankle
Injury to lateral ligament (usually anterior talofibular ligament)
Subtalar joint
Between talus and calcaneus (+ navicular)
Allows inversion/eversion during locomotion
Transverse tarsal joint
Allows eversion/inversion and pronation/supination
between calcaneus and talus AND cuboid and navicular
Important for standing on uneven ground
Plantar aponeurosis
- thickening of deep fascia
- protects underlying structure
- supports longitudinal arch
starts at calcaneus with longitudinal bands to to toes
Clinical significance of plantar aponeurosis
plantar fasciitis (inflammation due to overuse)
Arches of the foot
longitudinal and transverse arches
Function:
shock absorbers during locomotions
Act as springboards
Distribute weight to calcaneus and ball of foot
Longitudinal arches
Lateral and medial longitudinal arches
Lateral - calcaneus, cuboid, lateral metatarsals
medial - medial metatarsals, cuneiform, navicular, calcaneus
Lateral much less defines than medial
What support the longitudinal arches?
long tendons, intrinsic plantar muscles, intrinsic ligaments and plantar aponeurosis
Clinical implication of longitudinal arches?
Fallen medial longitudinal arch can lead to pes planus (flat feet)
Transverse arch
supported by long tendons (mainly fibularis longus)
Fibularis longus
long tendon supporting the transverse arch
Muscle compartments
Anterior - extend/invert foot- deep fibular nerve
Posterior - flex/invert foot - tibial nerve
Lateral - evert foot - superficial fibular nerve
Deep fibular nerve supplies
anterior muscle compartment which extends/invert foot
Tibial nerve
Posterior muscle compartment which flexes/inverts foot
Superficial fibular nerve
lateral muscle compartment - evert foot
Anterior compartment of leg
Three muscles
Extend (dorsiflex) and invert foot
Origin: tibia and fibula
Insertion: extensor retinaculum
Supplied by deep fibular nerve
Anterior leg muscles
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Tibialis anterior
origin: tibia and fibula
insertion: extensor retinaculum
Extends/inverts foot
supplied by deep fibular nerve
Extensor digitorum longus
origin: tibia and fibula
insertion: extensor retinaculum
Extends lateral 4 toes (not big toe)
Supplied by deep fibular nerve
Extensor hallucis longus
Origin: tibia & fibula
Inserts: extensor retinaculum
Extends great toe
Supplied by deep fibular nerve
Anterior compartment of leg
Extensor digitorum longus - middle and distal phalanges
Tibialis anterior - medial cuneiform and 1st metatarsal
Extensor hoods - dorsal digital expansions
Extensor hallucis longus - distal phalanx of great toe
Posterior compartment
two groups
Superficial - flex (plantarflex) foot and leg
Deep group - flex (plantarflex) and invert foot and flex toes
Superficial group of posterior compartment of leg
Flex (plantar flex) foot and leg
gastrocnemius - origin: condyles of femur
soleus - origin: tibia and fibula
plantaris - origin: femur
supplied by tibial nerve
gastrocnemius inserts into tendo calcaneus
Deep group of posterior compartment of leg
Flex (plantar flec) and invert foot and flex toes
Origin: tibia and fibula
Mirrors anterior compartment
Tibialis posterior - inverts foot
Flexor digitorum longus - flexor of lateral 4 toes - corsses tibialis posterior
Flexor hallucis longus - flexor of great toe
Insert into flexor retinaculum
Flexor digitorum longus
Flexes lateral 4 toes
to distal phalanges (crosses flexor hallucis longus)
Tibialis posterior
inverts foot
to medial cuneiform and navicular
Flexor hallucis longus
flexes great toe
to distal phalanx of great toe
Enters groove on talus and calcaneus
Lateral compartment of leg
Evert
Superficial fibular nerve
Origin: fibula
Fibularis longus (everts and plantar flexes foot)
Fibularis brevis
Fiburalis longus
Everts and plantar flexes foot
Origin: fibula
Inserts: Medial cuneiform & 1st metatarsal
fibularis brevis
everts foot
Origin: fibula
inserts: 5th metartarsal
Lateral ong tendons of the foot
Lateral: Extensor retinaculum containing extensor digitorum longus and extensor hallucis longus
Fibular retinaculum containing fibularis longus/brevis
Medial:
Tibialis anterior in medial side of extensor retinaculum
Tibialis posterior, flexor digitorum longus, flexor hallucis longus in flexor retinaculum
Intrinsic muscles of the foot
Many layers
dorsal extensors - 1 layer
plantar flexors/abductors/adductors - 4 layers
Blood supply
popliteal artery -> anterior tibial artery -> posterior tibial artery -> fibular artery
Tarsal tunnel
Flexor retinaculum Contents: Tibialis posterior Flexor Digitorum longus posterior tibial Artery/Vein tibial Nerve flexor Hallucis longus
Tom, Dick And Very Naughty Harry
Clinical relevance: pulse
Median/lateral plantar arteries
Lateral plantar artery
Forms deep plantar arch
Posterior tibial artery -> medial plantar artery and lateral plantar artery
Dorsalis pedis artery
Anterior compartment: anterior tibial artery goes to dorsalis pedis, anastomosis with deep palmar arch
Sits beside the extensor hallucis longus tendon
Nerve supply to the leg
supplied by the terminal branches of the sciatic nerve
Tibial - posterior compartment
Deep fibular - anterior compartment
Superficial fibular - lateral compartment
Tibial nerve
Tibial nerve
Posterior tibial artery
Tibial nerve enters tarsal tunnel
Give the medial and lateral plantar nerves
Motor: posterior compartment of leg and plantar intrinsic muscles
Clinical: tarsal tunnel syndrome
Common fibular nerve
common fibular nerve to superficial and deep fibular nerves
anterior tibial artery runs down the front
Motor: deep - anterior compartment of leg and dorsal intrinsic muscles
Superficial - lateral compartment of leg
Clinical: trauma to common fibular nerve (foot drop)
Cutaneous nerve
Medial/lateral plantal nerves (tibial) supply sole of foot
