Leg and Popliteal Fossa Flashcards
how many muscles are there in the anterior compartment of the leg?
4
name the 4 muscles in the anterior compartment of the leg
tibialis anterior extensor digitorum longus extensor hallucis longus peroneus tertius (fibularis tertius)
what innervates the anterior leg?
deep peroneal nerve (L4-L5)
what are the attachments of the tibialis anterior?
lateral tibia to base of metatarsal I
what is the general action of the anterior compartment of the leg?
dorsiflexion and inversion at ankle
what is the action of tibialis anterior?
dorsiflexion and inversion of foot
the tendons of which muscle can be palpated on the dorsum of the foot?
extensor digitorum longus
what are the attachments of the extensor digitorum longus?
lateral condyle of tibia and medial surface of fibular to each of the four lateral toes
what is the action of extensor digitorum longus?
extension of lateral 4 toes
dorsiflexion of foot
what are the attachments of extensor hallucis longus?
medial surface of fibular shaft - crosses anterior to ankle joint - base of distal phalanx of great toe
what are the actions of extensor hallucis longus?
extension of great toe
dorsiflexion of foot
what are the attachments of peroneus (fibularis) tertius?
medial surface of fibular
metatarsal V
what is the action of peroneus (fibularis) tertius?
eversion and dorsiflexion of foot
how many muscles are there in the lateral leg?
2
name the 2 muscles in the lateral leg?
peroneal longus
peroneal brevis
(fibularis!)
what is the action of the two lateral leg muscles?
eversion - realistically, prevention of excessive inversion of foot while running
describe the path of peroneal (fibularis) longus
origin: superior and lateral surface of fibula + lateral tibial condyle
tendon descends, passes into foot posterior to lateral malleolus
crosses under foot (like stirrup!) and attaches to medial bones - medial cuneiform and metatarsal I
what is the action of peroneal (fibularis) longus?
everision and plantar fexion
supports lateral and transverse arches of foot
describe the path of peroneal (fibularis) brevis
origin: inferior and lateral surface of fibular shaft
descends into foot posterior to lateral malleolus
attaches to tubercle on metatarsal V
what is the action of peroneal (fibularis) brevis?
eversion of foot
what innervates the lateral leg?
superficial peroneal nerve (L4-S1)
how many muscles are there in the posterior leg?
7
how many muscles are in the superficial layer of the posterior leg?
3
how many muscles are in the deep layer of the posterior leg?
4
name the 3 muscles in the superficial layer of the posterior leg?
gastrocnemius
plantaris
soleus
where do the superficial muscles of the posterior leg insert?
calcaneus - calcaneal tendon (Achille’s heel)
what is the action of the posterior leg muscles?
plantar flexion and inversion
what innervates the posterior leg?
tibial nerve (terminal branch of sciatic)
where do the two heads of gastrocnemius originate?
lateral = lateral femoral condyle medial = medial femoral condyle
what is the action of gastrocnemius?
plantar flexion at ankle
also crosses knee, so flexes there
name the 4 muscles innervated by the tibial nerve
the 3 superficial posterior leg muscles (gastrocnemius, plantaris, soleus) and the popliteus muscle
where does the plantaris originate?
lateral supracondylar line of femur
what is the action of plantaris?
plantar flexes at ankle, flexes at knee, although not vital for either of these movements
where does soleus originate?
soleal line of tibia and proximal fibular area
what is the action of soleus?
plantar flexion
name the 4 muscles of the deep layer of the posterior leg
popliteus
tibialis posterior
flexor digitorum longus
flexor hallucis longus
what is the action of popliteus?
“unlocks” knee by laterally rotating femur
what are the attachments of popliteus?
posterior tibia to lateral condyle of femur
what is the action of tibialis posterior?
inverts and plantar flexes foot
maintains medial arch of foot
what are the attachments of flexor digitorum longus?
medial surface of tibia to plantar surfaces of lateral 4 toes
what is the action of the flexor digitorum longus?
flexes lateral 4 toes
what are the attachments of flexor hallucis longus?
posterior surface of fibula to plantar surface of phalanx of great toe
what is the action of flexor hallucis longus?
flexes great toe
what forms the superiomedial border of the popliteal fossa?
semimembranous
what forms the superiolateral border of the popliteal fossa?
biceps femoris
what forms the inferomedial border of the popliteal fossa?
medial head of gastrocnemius
what forms the inferolateral border of the popliteal fossa?
plantaris and lateral head of gastrocnemius
what forms the floor of the popliteal fossa?
posterior knee joint capsule
what forms the roof of the popliteal fossa?
popliteal fascia and skin
what are the contents of the popliteal fossa?
(medial to lateral) popliteal artery popliteal vein tibial nerve common peroneal nerve
