leg LOs

Question 1

crural fascia

Answer 1

• separates the compartments of the leg
  
  • anterior crural intermuscular septum: anterior fibular border, separates anterior and lateral compartments
  • posterior CIS: posterior fibular border, separates posterior and lateral
  • transverse CIS: separates superficial and deep posterior compartment

Question 2

extensor retinacula

Answer 2

• part of talocrural fascia, stabilizes tendons around ankle
• superior ER: distal tibia to distal fibula
• inferior ER: calcaneus to navicular and medial maleolus

Question 3

fibular retinacula

Answer 3

• part of talocrural fascia
• commonly injured - tendons sublux over lateral maleolus
• superior fibular FR: lateral malleolus to calcaneus (superior to ankle joint)
• inferior fibular FR: inferior extensor retinaculum to calcaneus
  
  • over fibularis longus and brevis tendons
• flexor retinaculum: medial malleolus to calcaneus, forms tarsal tunnel

Question 4

anterior compartment of leg

Answer 4

• contents: tibialis anterior, extensor hallucis longus, extensor digitorum longus, fibularis tertius
• actions: ankle dorsiflexion/inversion, toe extension
  
  • fibularis tertius: ankle eversion
• innervation: deep fibular nerve
• blood supply: anterior tibial artery

Question 5

lateral compartment

Answer 5

• contents: fibularis longus, fibularis brevis
  
  • tendons run posterior of lateral malleolus
• actions: eversion, plantar flexion
• innervation: superficial fibular nerve
• blood supply: fibular artery

Question 6

superficial posterior compartment of leg

Answer 6

• contents: gastrocnemius, soleus, plantaris
  
  • gastroc + soleus : triceps surae
  • gastroc and plantaris cross both knee and ankle
• actions: ankle plantar flexion, weak knee flexion
• innervation: tibial nerve
• blood supply: posterior tibial artery

Question 7

deep posterior compartment of leg

Answer 7

• contents: popliteus, flexor digitorum longus, flexor hallucis longus, tibialis posterior
• actions: ankle plantar flexion/inversion, toe flexion, knee flexion
• innervation: tibial nerve
• blood supply: posterior tibial artery

Question 8

common fibular nerve axon function

Answer 8

• lateral sural: S/PS to skin over lateral aspect of leg
• deep fibular: S/PS/M to tibialis anterior, extesnor hallucis longus, extensor digitorum longus, and fibularis tertius
• superficial fibular: S/PS/M to fibularis longus, fibularis brevis

Question 9

tibial nerve axon functions

Answer 9

• sural: S/PS to skin over lateral leg and foot
• muscular: S/PS/M to gastroc, soleus, plantaris, popliteus, tibilais posterior, FDL, FHL
• medial plantar
• lateral plantar

Question 10

path taken by common fibular nerve

Answer 10

• deep to proximal fibularis longus, curves lateral to neck of fibula
  
  • splits deep to fibularis longus
• superficial fibular nerve begins at bifurcation to fibularis longus and brevis muscles
• deep fibular nerve approaches interosseous membrane, between tibialis anterior and EHL, descends with anterior tibial artery

Question 11

path taken by tibial nerve

Answer 11

• joins with popliteal artery and vein
  
  • travels with artery
• down the back of the leg, splits into medial and lateral plantar nerves