LL3. anterior/posterior leg Flashcards
action of anterior compartment of leg
dorsiflexion and extension of toes (metatarsal, interphalangeal joint)
Tibialis anterior origin
lateral tibia
Tibialis anterior insertion
medial cuneiform
Tibialis anterior action
inversion of foot
dorsiflexion
anterior leg innervation
deep fibular nerve
Extensor digitorum longus action
extends phalanges
dorsiflexion
Extensor digitorum longus action origin
lateral condyle of tibia/medial fibula
Extensor digitorum longus action insertion
lateral 4 digits
Extensor digitorum longus action position/palpation
positioned laterally and deep to the tibialis anterior
Its four tendons can be palpated on the dorsal surface of the foot
Extensor hallucis longus origin
medial surface of fibula
Extensor hallucis longus insertion
big toe (hallucis)
Extensor hallucis longus action
extends big toe
does everyone have fibilaris tertius?
nope
BLOOD SUPPLY to anterior leg
anterior tibial artery
-> pierces interosseous membrane to become anterior
when does anterior tibial artery become dorsal pedis
after ankle joint -> feel pulse
ANTERIOR TIBIAL STRESS SYNDROME
shin splints
microtrauma to tibialis anterior and periosteum of tibia
general action of lateral leg
eversion and weak plantar flexion
Peroneus (fibularis) longus origin
fibula
cause of foot drop
damage to common fibular nerve
= no dorsiflexion
Which muscle produces eversion at the subtalar joint?
fibularis tertius
the nerve roots of the deep fibular nerve
L4-S1
fibularis longus origin
superior/lateral surface of fibula
lateral condyle
fibularis longus insertion
1st metatarsal and medial cuneiform bone
fibularis longus action
weak plantar flexion
eversion
supports arch
lateral leg innervation
superficial fibular nerve
fibularis brevis origin
interosseus membrane
fibularis brevis insertion
5th metatarsal
fibularis brevis action
eversion
is fibularis brevis or longus more superficial?
longus is superficial to brevis
COMMON FIBULAR NERVE INJURY
- fractured neck of fibula = injures where nerve wraps round ⇒ foot drop
- casts = compresses neck of fibula
muscles of superior posterior leg
gastrocnemius
soleus
plantaris
insertion of posterior superficial muscles
form calcaneus tendon = achilles
innervation of deep posterior muscles
tibial branch of sciatic nerve
blood supply to posterior deep muscles
posterior tibial artery (branch of popliteal artery)
function of superficial posterior muscles
plantarflexion and flexion of toes
function of deep posterior muscles
flexion of toes
Gastrocnemius origin
medial condyle - m head
lateral condyle - l head
Gastrocnemius action
lot of force = plantarflexion (releve)
flexion of toes
flex knee
-> tires easily
gastrocnemius innervation
superficial fibular nerve
Soleus origin
Originates from the soleal line of the tibia and proximal fibula
Soleus action
plantarflexion (releve)
flexion of toes
contraction compresses veins for venous return
-> postural function
Plantaris origin
plantarflexion/knee flexion
popliteus origin, insertion, action
lateral condyle
proximal tibia, above soleus
lateral rotation of femur to allow flexion of knee
Flexor digitorum longus origin
medial tibia
Flexor digitorum longus action
flexion of lateral 4 toes
Flexor digitorum longus insertion
plantar surface of lateral 4 digits
