Tibial Nerve Flashcards
What are the roots of the tibial nerve?
L4-S3
What are the sensory functions of the tibial nerve?
Innervates the skin on the posterolateral side of the leg, lateral side of the foot, and the sole of the foot
What are the motor functions of the tibial nerve?
Innervates posterior compartment of the leg
What is the tibial nerve a branch of?
The sciatic nerve
Where does the tibial nerve arise?
At the apex of the popliteal fossa
What is the anatomical course of the tibial nerve?
It travels through the popliteal fossa
It continues its course down the leg, posterior to the tibia.
At the foot, it passes posteriorly and inferiorly to the medial malleolus, through a structure known as the tarsal tunnel
What does the tibial nerve do as it travels through the popliteal fossa?
Gives off branches to muscles in the superficial posterior compartment of the leg
Gives rise to branches that contribute towards the sural nerve
What does the sural nerve do?
Innervates the posterolateral aspect of the leg
What does the tibial nerve do during its course down the leg?
Supplies the deep muscles of the posterior leg
What is the tarsal tunnel covered with?
Superiorly, by the flexor retinaculum
What happens within the tarsal tunnel?
The tibial nerves gives branches to supply cutaneous innervation to the heal
Where does the tibial nerve terminate?
Immediately distal to the tarsal tunnel
How does the tibial nerve terminate?
By dividing into sensory branches, which innervate the sole of the foot
What is tarsal tunnel syndrome?
A condition where the tibial nerve is compressed within the tarsal tunnel
What are the main causes of tarsal tunnel syndrome?
Osteoarthritis
Rhuematoid arthritis
Post-trauma ankle deformities
What do patients with tarsal tunnel syndrome complain of?
Paresthesia in the ankle and sole of the foot, which can radiate up the leg slightly. It is aggravated by activity and relieved by rest
How can tarsal tunnel syndrome be treated?
Conservatively, by anti-inflammatory drugs and changes in footwear.
If thats not successful, the flexor retinaculum can be cut surgically, which releases the pressure
What muscles does the tibial nerve innervate?
All the muscles in the posterior compartment of the leg
What can the muscles in the posterior compartment of the leg be divided into?
A deep and superficial compartment
What muscles are in the deep compartment of the posterior leg?
Popliteus
Flexor hallucis longus
Flexor digitorum longus
Tibialis posterior
What does the popliteus do?
Laterally rotates the femur on the tibia to unlock the knee
What does the flexor hallucis longus do?
Flexes the big toe, and plantar flexes the ankle
What does the flexor digitorum longus do?
Flexes the other digits and plantar flexes the ankle
What muscles are in the superficial compartment of the posterior leg?
Plantaris
Soleus
Gastrocnemius
What does the plantaris do?
Plantar flexes the ankle
What does the soleus do?
Plantar flexes the ankle
What does the gastrocnemius do?
Plantar flexes the ankle and flexes the knee
What does the tibial nerve give off in the popliteal fossa?
Cutaneous branches
What happens to the cutaneous branches of the tibial nerve?
They combine with branches from the common fibular nerve to form the sural nerve
What does the sural nerve do?
Innervates the skin of the posterolateral side of the leg and the lateral side of the foot
How does the tibial nerve supply the sole of the foot?
Via thee branches, the medial calcaneal branches, the medial plantar nerve, and the lateral plantar nerve
Where do the medial calcaneal branches arise?
Within the tarsal tunnel
What do the medial calnaneal branches do?
Innervate the skin over the heel
What does the medial plantar nerve do?
Innervates the plantar surface of the medial three and a half digits, and the associated sole area
What does the lateral plantar nerve do?
Innervates the plantar surface of the lateral one and a half digits, and the associated sole area
How common is damage to the tibial nerve?
Rare
What is damage to the tibial nerve often a result of?
Direct trauma, entrapment through a narrow space, or compression for a long period of time
What does damage to the tibial nerve result in?
Loss of plantar flexion, loss of flexion of toes and weakened inversion
Why is inversion only weakened when theres tibial nerve damage?
The tibialis anterior can still invert the foot
