L17: Muscles of the Leg and Foot Flashcards
Muscles in the anterior compartment of the leg (crus)?
- tibialis anterior
- extensor digitorum longus
- extensor hallucis longus
- fibularis tertius
muscles in the lateral compartment of leg?
- fibularis longus
2. fibularis brevis
muscles in posterior compartment of leg?
- Gastrocnemius
- Soleus
- Plantaris
- Popliteus
- Tibialis posterior
- Flexor digitorum longus
- Flexor hallucis longus
what action does the anterior compartment of the leg perform?
- dorsiflex at ankle
- extend toes
origin and insertion of extensor digitorum longus?
origin: anterior tibia and fibula
insertion: distal phalanx 2nd -5th toes
origin/insertion of fibularis tertius?
origin: anterior tibia
insertion: bast of 5th metatarsal
origin/insertion of extensor hallucis longus?
origin: anterior fibula
insertion: distal phalanx 1st toe
tibialis anterior is the strongest ____?
dorsiflexor
origin/insertion of tibialis anterior?
origin: anterior tibia
insertion: base of 1st metatarsal and medial cuneiform
action of lateral leg compartment muscles (fibularis longus/brevis)
- ankle eversion
- weak plantar flexion
Origin of medial head of gastrocnemius?
medial condyle of femur
origin of lateral head of gastrocnemius?
lateral femoral condyle
origin of soleus?
proximal tibia and fibula
origin of plantaris
superior lateral femoral condyle
what are the triceps surae? what action?
- gastrocnemius and soleus
- plantar flexors
origin/insertion of popliteus?
lateral femoral condyle > post proximal tibia
action of tibialis posterior? *
- primary inverter
- dynamic stabiliser of medial longitudinal arch
origin/insertion of tibialis posterior?
posterior tibia > metatarsals 2-4 and all tarsals except talus and calcaneus
origin/insertion of flexor digitorum longus?
posterior tibia > distal phalanx digits 2-5
origin/insertion flexor hallucis longus?
posterior fibula > 1st toe (hallux)
why can’t the tibiofemoral joint act as a pure hinge joint?
- the difference in length of the articular surface area of medial and lateral femoral condyles
- results in some rotation occurring during flexion-extension
what happens to the femur during weight-bearing sit to stand?
- femur rotates medially near full extension = screw home mechanism
comparison of muscle group strength?
plantar flexor muscle mass > dorsiflexors
- greater PF leverage (calcaneal tuberosity)
- plantarflexion > 3x dorsiflexion peak torque
plantarflexion __x> than dorsiflexion peak torque?
3x
inversion strength is equal to?
eversion strength
what does the extensor digitorum brevis extend?
- MTP, PIP, DIP of only toes 2-4
what does extensor hallucis brevis extend?
MTP of the hallux
what is plantar fascia?
- thickening of deep fascia of the foot
- encloses the plantar muscles
origin/insertion of plantar fascia?
- medial process of tuberosity of calcaneus > 1st and 5th metatarsals
- phalanges
- skin
function of plantar fascia?
- stabilisation of skin on sole
- support shape of foot and arches
- twice as strong as any other ligament in the foot
stretch and recoil of plantar fascia and other plantar ligaments can save __% of the cost of running?
17%
