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Flashcards in Tibial nerve Deck (31):

nerve roots, sensory and motor function?

Sensory: skin of posterolateral leg & lateral side of foot, sole of foot
Motor: posterior compartment of leg


how does tibial nerve arise?

a branch of sciatic nerve, from the apex of the popliteal fossa, the tibial nerve travels through popliteal fossa to the superficial posterior compartment of leg (muscles)
gives rise to sural nerve (posterolateral sensory of leg)


describe the course of the tibial nerve down the leg to the foot after popliteal fossa

posterior to tibial - supplying deep muscles of leg
then travels posterior inferior to tarsal tunnel


how do you have nerves supplying cutaneous innervation to heel?

at the tarsal tunnel, the tibial nerve branches off to supply cutaneous innervation of heel


how does innervation of the foot arise?

distal (away) to the tarsal tunnel, tibial nerve terminates, dividing into sensory branches which innervate the sole of the foot


what is the tarsal tunnel covered by?

flexor retinaculum


Clinical: tarsal tunnel syndrome
what is it?

tibial nerve compressed within tarsal tunnel (posterior & inferior to medial malleolus)


causes of tarsal tunnel syndrome?

osteoarthritis (bone loose mass)
rheumatoid arthritis (inflammation of joints)
post-trauma ankle deformaties


What are the presenting symptoms of tarsal tunnel syndrome?

parasthesia of the ankle foot, can radiate to leg
aggregating factors: activity
relieving factors: rest


Treatment for tarsal tunnel syndrome?

anti-inflammatory drugs & changes in footware
surgical decompression of flexor retinaculum (by cutting it)


Name the deep muscles of the posterior compartment of the leg innervated by the tibial nerve

1. popliteus
2. flexor hallucis longus
3. flexor digitorum longus
4. tibialis posterior


Name the superficial posterior muscles of the leg

1. plantaris
2. soleus
3. gastrocnemius


Which muscles does the tibial nerve innervate?

all muscles of the posterior compartment of the leg


What is the action that the superficial muscles of the posterior leg carry out?

plantaris, soleus, gastrocnemius
plantar flexes the ankle


What is the function of the popliteus?

to laterally rotate the femur on the tibia to unlock the knee
this begins flexion to unlock the knee


What is locking the knee?

when the knee is in full extension, the femur slightly medially rotates on the tibia to lock the knee joint in place


What is the function of the flexor hallucis longus?

to flex the hallux (big toe) and to plantar flex at the ankle joint


What is the function of the flexor digitorum longus?

to flex the other 4 digits and to plantar flex the ankle


What is the function of the tibialis posterior?

inverts foot with tibialis anterior and plantar flexes the ankle


What is the function of the plantaris?

plantar flex ankle


What is the function of the soleus?

plantar flex the ankle


What is the function of the gastrocnemius?

plantar flexes the ankle and flexes the knee (cross 2 joints)


How does the sural nerve arise?

branches from the tibial nerve in the POPLITEAL FOSSA combine with branches from the common fibular nerve (the other branch of the sciatic nerve)


What does the sural nerve innervate?

sensory nerve innervating skin of posteriolateral side of leg and lateral side of foot


Which 3 branches of which nerve supplies the sole of the foot's sensory?

1. medial calcaneal branch (middle of calcaneus - heel of foot)
2. medial plantar nerve (medial side of sole of foot)
3. lateral plantar nerve (lateral side of sole of foot)

all branches of the tibial nerve


Does the sural nerve innervate the sensory of the foot?

a small area of plantar, proximal lateral foot
next to medial calcaneal branch


What does the medial calcaneal branch innervate? where does it arise from?

arise from tarsal tunnel and innervate skin over heel


What does the medial plantar nerve innervate?

plantar surface of medial 3 1/2 digits and associated sole area


What does the lateral plantar nerve innervate?

plantar surface of the lateral 1 1/2 digits, and associated sole area


Clinical: damage to tibial nerve
how does it occur?

rare, often through direct trauma, entrapment through narrow space or compression for a long period of time


What does damage in the tibial nerve result in?

loss of plantar flexion (all superficial muscles and deep flexors), loss of flexion of toes (flexor digitorum & hallucis longus) and weakened inversion (tibialis anterior still works)