Official reprint from UpToDate®
www.uptodate.com ©2016 UpToDate®

Overview of lower extremity peripheral nerve syndromes

Seward B Rutkove, MD
Section Editor
Jeremy M Shefner, MD, PhD
Deputy Editor
John F Dashe, MD, PhD


This topic provides an overview of lower extremity peripheral nerve syndromes. Peripheral nerve syndromes involving the upper extremities are discussed separately. (See "Overview of upper extremity peripheral nerve syndromes".)


Nerve roots emerge from the spinal column from the L2 to S4 levels through the neural foramina and join to form a complex entity known as the lumbosacral plexus (figure 1). Unlike the brachial plexus, in which the anatomy is delineated through trunks, divisions, and cords, the lumbosacral plexus has only two main components: the lumbar plexus (made up of nerve fibers from the L2 through L5 roots) and the sacral plexus (made up of nerve fibers from the S1 through S4 roots).

The largest nerve that emerges from the lumbar plexus is the femoral nerve, which descends beneath the inguinal ligament before dividing into a number of smaller branches innervating the anterior thigh musculature and skin (figure 2). One pure sensory branch, the saphenous nerve, continues down the medial leg to the arch of the foot. Although the subject of some disagreement, the iliopsoas muscle is innervated by the femoral nerve or a small nerve of its own that travels alongside the femoral. The obturator nerve also emerges from the lumbar plexus, descending more medially than the femoral, exiting the pelvis through the obturator foramen where it innervates the thigh adductors and a small cutaneous area in the medial thigh.

A small nerve, the lateral femoral cutaneous nerve, also has its origin directly from the plexus. It travels lateral to the femoral nerve underneath the inguinal ligament to innervate the skin of the lateral thigh.

Contributions from the lower lumbar plexus and upper sacral plexus give rise to the sciatic nerve. This nerve passes through the sciatic foramen and descends the posterior aspect of the leg until it reaches the popliteal fossa, where it divides into the posterior tibial and common peroneal nerves.


Subscribers log in here

To continue reading this article, you must log in with your personal, hospital, or group practice subscription. For more information or to purchase a personal subscription, click below on the option that best describes you:
Literature review current through: Sep 2016. | This topic last updated: Dec 22, 2014.
The content on the UpToDate website is not intended nor recommended as a substitute for medical advice, diagnosis, or treatment. Always seek the advice of your own physician or other qualified health care professional regarding any medical questions or conditions. The use of this website is governed by the UpToDate Terms of Use ©2016 UpToDate, Inc.
  1. Frymoyer JW. Lumbar disk disease: epidemiology. Instr Course Lect 1992; 41:217.
  2. Komori H, Shinomiya K, Nakai O, et al. The natural history of herniated nucleus pulposus with radiculopathy. Spine (Phila Pa 1976) 1996; 21:225.
  3. Nardin RA, Patel MR, Gudas TF, et al. Electromyography and magnetic resonance imaging in the evaluation of radiculopathy. Muscle Nerve 1999; 22:151.
  4. Katirji MB, Wilbourn AJ. Common peroneal mononeuropathy: a clinical and electrophysiologic study of 116 lesions. Neurology 1988; 38:1723.
  5. Pigott TJ, Jefferson D. Idiopathic common peroneal nerve palsy--a review of thirteen cases. Br J Neurosurg 1991; 5:7.
  6. Sidey JD. Weak ankles. A study of common peroneal entrapment neuropathy. Br Med J 1969; 3:623.
  7. Mont MA, Dellon AL, Chen F, et al. The operative treatment of peroneal nerve palsy. J Bone Joint Surg Am 1996; 78:863.
  8. McManis PG. Sciatic nerve lesions during cardiac surgery. Neurology 1994; 44:684.
  9. Bailie DS, Kelikian AS. Tarsal tunnel syndrome: diagnosis, surgical technique, and functional outcome. Foot Ankle Int 1998; 19:65.
  10. Turan I, Rivero-Melián C, Guntner P, Rolf C. Tarsal tunnel syndrome. Outcome of surgery in longstanding cases. Clin Orthop Relat Res 1997; :151.
  11. Macaré van Maurik JF, Schouten ME, ten Katen I, et al. Ultrasound findings after surgical decompression of the tarsal tunnel in patients with painful diabetic polyneuropathy: a prospective randomized study. Diabetes Care 2014; 37:767.
  12. Yuen EC, Olney RK, So YT. Sciatic neuropathy: clinical and prognostic features in 73 patients. Neurology 1994; 44:1669.
  13. Srinivasan J, Ryan MM, Escolar DM, et al. Pediatric sciatic neuropathies: a 30-year prospective study. Neurology 2011; 76:976.
  14. Kirschner JS, Foye PM, Cole JL. Piriformis syndrome, diagnosis and treatment. Muscle Nerve 2009; 40:10.
  15. Halpin RJ, Ganju A. Piriformis syndrome: a real pain in the buttock? Neurosurgery 2009; 65:A197.
  16. Wong CA, Scavone BM, Dugan S, et al. Incidence of postpartum lumbosacral spine and lower extremity nerve injuries. Obstet Gynecol 2003; 101:279.
  17. Moore AE, Stringer MD. Iatrogenic femoral nerve injury: a systematic review. Surg Radiol Anat 2011; 33:649.
  18. Al-Ajmi A, Rousseff RT, Khuraibet AJ. Iatrogenic femoral neuropathy: two cases and literature update. J Clin Neuromuscul Dis 2010; 12:66.
  19. al Hakim M, Katirji B. Femoral mononeuropathy induced by the lithotomy position: a report of 5 cases with a review of literature. Muscle Nerve 1993; 16:891.
  20. Massey EW. Sensory mononeuropathies. Semin Neurol 1998; 18:177.
  21. Kuntzer T, van Melle G, Regli F. Clinical and prognostic features in unilateral femoral neuropathies. Muscle Nerve 1997; 20:205.
  22. Stewart JD. Other mononeuropathies of the lower limb. In: Neuromuscular Function and Disease, 1st edition, Brown WF, Bolton CF, Aminoff MJ (Eds), WB Saunders Company, Philadelphia 2002. Vol 1, p.1004.
  23. Rogers LR, Borkowski GP, Albers JW, et al. Obturator mononeuropathy caused by pelvic cancer: six cases. Neurology 1993; 43:1489.
  24. Kissel JT, Mendell JR. Vasculitic neuropathy. Neurol Clin 1992; 10:761.