Sciatic Nerve Flashcards
What is the sciatic nerve?
The sciatic nerve runs from the roots of L4-S3. It innervates the posterior thigh compartment and splits into a tibial and common fibular nerves, which occurs above the popliteal fossa.
What is the tibial nerve?
It innervates the muscles of the posterior leg compartment, and provides innervation to the majority of the muscles of the foot.
What is the common peroneal nerve?
It travels posterior to the tendon of the biceps femoris and crosses the neck of the fibula. It splits into a superficial fibular nerve and deep fibular nerve.
What is the role of the superficial peroneal nerve?
It innervates the muscles of the lateral leg of the fibularis longus and the fibularis brevis and passes between these muscles. It is important for ankle eversion.
In the distal 1/3rd of the leg, it pierces the fascia to become superficial and gives rise to the dorsal intermediate cutaneous branches and dorsal medial intermediate cutaneous branches.
What is the role of the deep fibular nerve?
It supplies the muscles of the anterior compartment of the leg, intrinisc muscles of the foot dorsum, and the web space between the 1st and 2nd toe. This nerve is important for foot dorsiflexion, and injury will result in foot drop so there are issues with the swing phase.
What is the role of the medial plantar nerve?
It innervates 3 and 1/2 toes, similar to the median nerve in the hand. It innervates the 1st lumbricle, abductor hallucis and flexor digitorum brevis and flexor hallucis brevis.
What s the role of the lateral plantar nerve?
Provides innervation to majority of the intrinsic muscles of the foot. It innervates 2nd-4th lumbricles, interossei, adductor hallucis, quadratus plantae and abductor digiti minimis.
The first branch of this is the Baxter’s nerve.
Which nerve is affected by plantar fascilitis?
Baxter’s nerve.
When does the sciatic nerve bifurcate?
Superior border of popliteal fossa.
