Sciatic nerve  
 
posterior view
 
 
  • The sciatic nerve is formed by the ventral rami of L4-S3.

  • The sciatic nerve is comprised of the tibial nerve and common fibular nerve surrounded by a common epineurium.

  • The sciatic nerve exits the pelvis via the greater sciatic foramen, typically inferior to piriformis muscle.

  • The sciatic nerve provides motor innervation to the muscles of the posterior compartment of the thigh, the "hamstring portion" of adductor magnus and all muscles of the leg and foot.

  • The sciatic nerve provides sensory innervation to the skin of the lateral aspect of the leg (anterolateral and posterolateral), and almost all of the foot (exception is the medial part of the foot that is innervated by saphenous nerve).

  • Injury to the sciatic nerve typically produces: complete motor loss of the muscles of the posterior thigh, leg and foot; sensory loss over the territories described above.