Medscape is available in 5 Language Editions – Choose your Edition here.


Foot Drop Workup

  • Author: James W Pritchett, MD; Chief Editor: Vinod K Panchbhavi, MD, FACS  more...
Updated: May 26, 2016

Laboratory Studies

Workup of foot drop proceeds according to the suspected cause. In cases where a cause (eg, trauma) is readily identified, no specific diagnostic laboratory studies are required. In cases where unilateral foot drop occurs spontaneously in a previously healthy patient, further investigation into metabolic causes (eg, diabetes, alcohol abuse, and exposure to toxins) is required. The following tests may be helpful:

  • Fasting blood sugar
  • Hemoglobin A1c
  • Erythrocyte sedimentation rate (ESR)
  • C-reactive protein (CRP)
  • Serum protein electrophoresis/immunoelectro-osmophoresis
  • Blood urea nitrogen (BUN)
  • Creatinine
  • Vitamin B12 level

Radiography and Ultrasonography

If foot drop is posttraumatic, plain films of the tibia, fibula, and ankle are appropriate to uncover any bony injury. In the absence of trauma, when anatomic dysfunction (eg, Charcot joint) is suspected, plain films of the foot and ankle provide useful information.

If bleeding is suspected in a patient with a hip or knee prosthesis, ultrasonography can be helpful.


Magnetic Resonance Neurography

If a tumor or a compressive mass lesion to the peroneal nerve is being investigated, magnetic resonance neurography (MRN) may be considered. MRN has made it possible to produce high-resolution images of peripheral nerves, as well as associated intraneural and extraneural lesions.

MRN can be performed by using a standard 1.5 Tesla magnetic resonance imaging (MRI) system and special phased-array imaging surface coils.[10] Image data are acquired simultaneously from multiple receive-only surface coils. The image data from each coil in the array are combined to form a composite image with an improved signal-to-noise ratio.

Compared with standard MRI, MRN allows faster acquisition of anatomically detailed images, a smaller field of view, higher resolution, and thinner sections. By virtue of these features, MRN images are capable of showing the fascicular organization of normal peripheral nerves, thereby rendering the nerves more clearly distinguishable from other tissue (eg, tumor or blood vessels). In one study, the fascicular structure seen on MRN was found to be functional by using intraoperative electrophysiologic testing; the nonfascicular structures were nonfunctional.

Images can be processed further to allow stacking of axial sections and slicing of data in another plane of section. This is helpful in mapping the longitudinal extent of nerve involvement.



In addition to the metabolic disorders listed above, the differential diagnosis of spontaneous foot drop includes spasticity, dystonia, motor neuron disease, L5 radiculopathy, lumbosacral plexopathy, sciatic nerve palsy, compressive peroneal neuropathy, peripheral neuropathy, and some myopathies.

Electromyography (EMG) is useful in differentiating among these diagnoses. This study can confirm the type of neuropathy, establish the site of the lesion, estimate the extent of injury, and provide a prognosis. Sequential studies are useful for monitoring recovery in patients with acute lesions.

Contributor Information and Disclosures

James W Pritchett, MD Chief of Orthopedic Surgery, Swedish Orthopedic Institute; Active Staff, Swedish Medical Center

James W Pritchett, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American College of Surgeons, Washington State Medical Association, Association of Bone and Joint Surgeons

Disclosure: Nothing to disclose.


Margaret A Porembski, MD Attending Physician, Oklahoma Hand Fellowship

Margaret A Porembski, MD is a member of the following medical societies: American College of Surgeons, American Medical Association, American Society for Surgery of the Hand

Disclosure: Nothing to disclose.

Chief Editor

Vinod K Panchbhavi, MD, FACS Professor of Orthopedic Surgery, Chief, Division of Foot and Ankle Surgery, Director, Foot and Ankle Fellowship Program, Department of Orthopedics, University of Texas Medical Branch School of Medicine

Vinod K Panchbhavi, MD, FACS is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American College of Surgeons, American Orthopaedic Association, American Orthopaedic Foot and Ankle Society, Orthopaedic Trauma Association, Texas Orthopaedic Association

Disclosure: Serve(d) as a speaker or a member of a speakers bureau for: Styker.


John S Early, MD Foot/Ankle Specialist, Texas Orthopaedic Associates, LLP; Co-Director, North Texas Foot and Ankle Fellowship, Baylor University Medical Center

John S Early, MD is a member of the following medical societies: American Academy of Orthopaedic Surgeons, American Medical Association, American Orthopaedic Foot and Ankle Society, Orthopaedic Trauma Association, and Texas Medical Association

Disclosure: AO North America Honoraria Speaking and teaching; Stryker Consulting fee Consulting; Biomet Consulting fee Consulting; AO North America Grant/research funds fellowship funding; MMI inc Honoraria Speaking and teaching; Osteomed Consulting fee Consulting; MedHab Inc Management position

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Medscape Salary Employment

  1. Stewart JD. Foot drop: where, why and what to do?. Pract Neurol. 2008 Jun. 8(3):158-69. [Medline].

  2. Cohen DE, Van Duker B, Siegel S. Common peroneal nerve palsy associated with epidural analgesia. Anesth Analg. 1993 Feb. 76(2):429-31. [Medline].

  3. Pritchett JW. Lumbar decompression to treat foot drop after hip arthroplasty. Clin Orthop. 1994 Jun. (303):173-7. [Medline].

  4. Weber ER, Daube JR, Coventry MB. Peripheral neuropathies associated with total hip arthroplasty. J Bone Joint Surg [Am]. 1976 Jan. 58(1):66-9. [Medline].

  5. Asp JP, Rand JA. Peroneal nerve palsy after total knee arthroplasty. Clin Orthop. 1990 Dec. (261):233-7. [Medline].

  6. Matsui H, Kanamori M, Kawaguchi Y. Clinical and electrophysiologic characteristics of compressed lumbar nerve roots. Spine. 1997 Sep 15. 22(18):2100-5. [Medline].

  7. Blandy JP, Fuller R. March gangrene; ischaemic myositis of the leg muscle from exercise. J Bone Joint Surg Br. 1957 Nov. 39-B (4):679-93. [Medline]. [Full Text].

  8. Weyns FJ, Beckers F, Vanormelingen L, Vandersteen M, Niville E. Foot drop as a complication of weight loss after bariatric surgery: is it preventable?. Obes Surg. 2007 Sep. 17(9):1209-12. [Medline].

  9. Koffman BM, Greenfield LJ, Ali II, Pirzada NA. Neurologic complications after surgery for obesity. Muscle Nerve. 2006 Feb. 33(2):166-76. [Medline].

  10. Kuntz C 4th, Blake L, Britz G. Magnetic resonance neurography of peripheral nerve lesions in the lower extremity. Neurosurgery. 1996 Oct. 39(4):750-6; discussion 756-7. [Medline].

  11. Elfar JC, Jacobson JA, Puzas JE, Rosier RN, Zuscik MJ. Erythropoietin accelerates functional recovery after peripheral nerve injury. J Bone Joint Surg Am. 2008 Aug. 90(8):1644-53. [Medline].

  12. Menotti F, Laudani L, Damiani A, Orlando P, Macaluso A. Comparison of walking energy cost between an anterior and a posterior Ankle-Foot Orthosis (AFOs) in patients with foot drop. J Rehabil Med. 2014 Jun 19. [Medline].

  13. Ring H, Treger I, Gruendlinger L, Hausdorff JM. Neuroprosthesis for footdrop compared with an ankle-foot orthosis: effects on postural control during walking. J Stroke Cerebrovasc Dis. 2009 Jan. 18(1):41-7. [Medline].

  14. Chae J, Sheffler L, Knutson J. Neuromuscular electrical stimulation for motor restoration in hemiplegia. Top Stroke Rehabil. 2008 Sep-Oct. 15(5):412-26. [Medline].

  15. Kluding PM, Dunning K, O'Dell MW, Wu SS, Ginosian J, Feld J, et al. Foot Drop Stimulation Versus Ankle Foot Orthosis After Stroke: 30-Week Outcomes. Stroke. 2013 May 2. [Medline].

  16. van Swigchem R, van Duijnhoven HJ, den Boer J, Geurts AC, Weerdesteyn V. Effect of peroneal electrical stimulation versus an ankle-foot orthosis on obstacle avoidance ability in people with stroke-related foot drop. Phys Ther. 2012 Mar. 92(3):398-406. [Medline].

  17. Chou CH, Hwang YS, Chen CC, Chen SC, Lai CH, Chen YL. FES for abnormal movement of upper limb during walking in post-stroke subjects. Technol Health Care. 2014 Jul 2. [Medline].

  18. Bethoux F, Rogers HL, Nolan KJ, et al. Long-Term Follow-up to a Randomized Controlled Trial Comparing Peroneal Nerve Functional Electrical Stimulation to an Ankle Foot Orthosis for Patients With Chronic Stroke. Neurorehabil Neural Repair. 2015 Nov-Dec. 29 (10):911-22. [Medline].

  19. Miller L, Rafferty D, Paul L, Mattison P. A comparison of the orthotic effect of the Odstock Dropped Foot Stimulator and the Walkaide functional electrical stimulation systems on energy cost and speed of walking in Multiple Sclerosis. Disabil Rehabil Assist Technol. 2014 Mar 17. [Medline].

  20. Aono H, Iwasaki M, Ohwada T, Okuda S, Hosono N, Fuji T, et al. Surgical outcome of drop foot caused by degenerative lumbar diseases. Spine. 2007 Apr 15. 32(8):E262-6. [Medline].

  21. Pritchett JW. Nerve injury following hip replacement; treatment by shortening. Clin Orthop Relat Research. 2004. (418):168-71.

  22. Kim DH, Kline DG. Management and results of peroneal nerve lesions. Neurosurgery. 1996 Aug. 39(2):312-9; discussion 319-20. [Medline].

  23. Nath RK, Lyons AB, Paizi M. Successful management of foot drop by nerve transfers to the deep peroneal nerve. J Reconstr Microsurg. 2008 Aug. 24(6):419-27. [Medline].

  24. Soares D. Tibialis posterior transfer for the correction of foot drop in leprosy. Long-term outcome. J Bone Joint Surg Br. 1996 Jan. 78(1):61-2. [Medline]. [Full Text].

  25. Shah RK. Tibialis posterior transfer by interosseous route for the correction of foot drop in leprosy. Int Orthop. 2009 Jan 10. [Medline].

  26. Rodriguez RP. The Bridle procedure in the treatment of paralysis of the foot. Foot Ankle. 1992 Feb. 13(2):63-9. [Medline].

  27. Johnson JE, Paxton ES, Lippe J, Bohnert KL, Sinacore DR, Hastings MK, et al. Outcomes of the Bridle Procedure for the Treatment of Foot Drop. Foot Ankle Int. 2015 Nov. 36 (11):1287-96. [Medline].

  28. Werner BC, Norte GE, Hadeed MM, Park JS, Miller MD, Hart JM. Peroneal Nerve Dysfunction due to Multiligament Knee Injury: Patient Characteristics and Comparative Outcomes After Posterior Tibial Tendon Transfer. Clin J Sport Med. 2016 Jan 19. [Medline].

  29. Movahedi Yeganeh M. Triple Tendon Transfer for Correction of Foot Deformity in Common Peroneal Nerve Palsy. Foot Ankle Int. 2016 Feb 9. [Medline].

Diagram of ground reaction vector during heel strike.
Common and superficial peroneal nerves, branches, and cutaneous innervation.
Deep peroneal nerve, branches, and cutaneous innervation.
Incisions for Bridle procedure.
Posterior leg with retrieved posterior tibial tendon above ankle. Window in interosseous membrane is labeled with X.
Posterior tibial tendon (C) is pulled through slit in anterior tibial tendon (A) and inserted into second cuneiform. Posterior tibial tendon is anastomosed to anterior tibial tendon and distal stump of peroneus longus (B) that has been rerouted anterior to lateral malleolus.
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.