Lower Limb 3 Flashcards
Musculature of leg split into what three compartments?
Anterior
Posterior
Lateral
What are the anterior leg muscles?
Tibialis anterior
Extensor digitorum longus
Extensor hallucis longus
Fibularis tertius
What is the action of tibialis anterior?
Dorsiflexes ankle, inverts the foot
Where does tibialis anterior insert?
Arch of the foot
What is the action of extensor digitorum longus?
Dorsiflexes ankle, extends the four digits
What is the action of extensor hallucis longus?
Dorsiflexes ankle, extends the big toe
What is the action of fibularis tertius?
Dorsiflexes ankle, everts the foot
What nerve supplies the anterior leg compartment?
Deep fibular nerve
What does the sciatic nerve divide into?
Common fibular and tibial nerve
After the external iliac artery crosses what structure does it become the femoral artery?
Inguinal ligament
Where does the femoral artery become the popliteal artery?
When it passes the knee
What does the popliteal artery divide into?
Anterior tibial and a trunk which gives rise to the posterior tibial artery and the fibular artery
What is the arterial supply to the anterior leg?
Anterior tibial artery
What is the course of the anterior tibial artery?
Runs length of the leg into the foot where it becomes the dorsalis pedis artery
Where does dorsalis pedis run?
Midway between the malleoli
What muscles are in the lateral compartment of the leg?
Fibularis longus and fibularis brevis
What structure does fibularis longus go behind?
Lateral malleolus
What is the action of fibularis longus and brevis?
Plantarflex and evert the foot
What nerve innervates the lateral compartment of the leg?
Superficial fibular
Where can the superficial fibular nerve be seen?
Next to the superficial muscles of the lateral compartment
Injury to the fibular nerve leads to what?
Foot drop
Reasons for injury: fractured fibular neck, stretched (e.g. knee joint injured)
Affects all the muscles of the anterior and lateral compartment –> unable to dorsiflex –> footdrop
What muscles are on the dorsum of the foot?
Extensor hallucis brevis
Extensor hallucis brevis
What nerve innervates the muscles on the dorsum of the foot?
Deep fibular nerve
What kind of joint is the ankle joint?
Synovial hinge
What is the anatomy of the ankle joint?
Tibia and fibular bound together by strong tibiofibular ligaments - this forms a bracket shaped socket, covered in hyaline cartilage known as the malleolar mortoise
Body of talus fits snugly into mortise
Socket articulates with the pulley shaped trochlea of the talus bone
What bones articulate in the ankle joint?
Distal end of the tibia and fibular articulate with the superior end of the talus bone
When is malleolar grip tightest?
Dorsiflexion of the ankle
When is the ankle joint unstable?
Plantarflexion of the ankle
What forms the lateral malleolus?
Fibula
What forms the medial malleolus?
Tibia
What are the ankle joints?
Medial (deltoid) ligament - consists of 4 ligaments that fan out from the medial malleolus
Lateral ligament - weakest - 3 components
What is an ankle sprain?
Torn fibres of ankle ligament
Usually inversion in jury
What movements occur at the ankle?
Dorsiflexion
Plantarflexion
What are the dorsiflexors of the ankle?
Anterior compartment - tibialis anterior, extensor digitorum longus, extensor hallucis longus
What are the plantarflexors of the ankle?
Posterior compartment - gastrocnemius, soleus, posterior tibialis, plantaris
What types of joints are the tibiofibular?
Proximal - synovial plane
Distal - syndesmosis (fibrous)
Interosseous membrane spans the length of the tibia and fibula
