A common problem for which patients consult neurologists like me is foot drop. As the name says, they have foot drop and hence are unable to dorsiflex their foot. As a result they are likely to catch their foot on the ground while walking and thus are prone to falls and this brings them to medical attention. Foot drop should be differentiated from frail foot. In foot drop, patients are unable to dorsiflex their foot while those who have a frail foot are unable to dorsiflex as well as unable to planter flex the foot (that is they are unable to pull their foot up or push down their foot as when you press down on a gas pedal).
Foot drop might occur suddenly (acutely) or may be more insidious and the causes for both vary. Before we discuss the causes of foot drop, it is helpful to know a little about the relevant anatomy. The muscle which helps to dorsiflex the foot is called tibialis anterior and it is supplied by a nerve called the peroneal nerve. The peroneal nerve is a branch of the sciatic nerve. The sciatic nerve is formed by the lower lumbar and sacral nerve roots and forms a part of the lumbosacral plexus. The peroneal nerve in the knee area is quite superficial as it cross the neck of the fibula (fibula is one of the bones in the lower leg along with the larger tibia). As the nerve is superficial it is prone to compression across the neck of the fibula.
So lets now discuss some of the common causes of foot drop. If suppose you suffer a fracture across the neck of the fibula, or have a gun shot wound to that area, or during knee surgery the peroneal nerve is accidently transected, you shall develop a foot drop. In all of the above the cause is injury to the peroneal nerve.
But peroneal compression may also occur due to other more subtle causes. One of the most common causes of foot drop is habitual leg crossing. This is most commonly seen in obese persons or in diabetics who lose weight. After weight loss they can cross their legs more easily and may develop a foot drop. Why does this occur you may ask? Well the answer is simple, as I told you before the peroneal nerve is quite superficial and hence prone to compression. When you cross your leg, the nerve may get pinched against the other knee and if you do not relieve the pressure soon, you can develop a foot drop. A common scenario is that the person is sitting with his legs crossed on a long flight, or might have fallen asleep with his leg pressed against the side rails of the bed (this is common in hospitalized patients in the intensive care unit or also when patients are undergoing surgery in the OR), they wake up and find they have a foot drop. The good news is that the prognosis for this type of compression injury to the peroneal nerve is rather good. Once the pressure is released, these patients usually make a full recovery over a few days to weeks and their foot drop goes away.
They can though be other more proximal causes of foot drop. You can have compression or injury to the sciatic nerve or to the lumbosacral plexus (remember I told you, that the peroneal nerve is a branch of the sciatic nerve). Compression of the sciatic nerve may at times be due to a tumor or mass in the pelvis or in the thigh or knee area.
Lower lumbar disc herniation may also result in a drop foot. This is commonly seen in L5 disc herniation. Patients usually present with radicular pain radiating down the leg, though sometimes this may be absent.
Diagnosis and management of foot drop: the diagnosis of foot drop is clinical and depending upon your examination findings, your doctor may or may not order other tests to confirm at what level is the problem. He may order a nerve conduction study and an EMG (needle study, electromyogram) to check for the the sciatic and peroneal nerves. If warranted an MRI of the lower back and of the plexus may be done.
The treatment depends upon the cause. If the foot drop is because of habitual leg crossing, then all what may be needed is to advise the patient not to cross his legs. The recovery is spontaneous. If a mass is the cause then well depending upon what it is, the treatment varies. Patients usually need a ankle foot orthosis or a foot drop splint. This splints the foot up and prevents fall.
I hope this is helpful to some of you.
Personal Regards,
Nitin Sethi, MD
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Tags: ankle foot orthosis, disc herniation, fibula neck, foot drop, foot drop splint, frail foot, peroneal nerve, sciatic nerve
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Hi,
I suffered a L5 disc prolapse in December 2007. Before my operation i noticed i was suffering from foot drop. after the op my foot did not recover but has improved can you help with a prognosis for recovery or any other info that may help
Dear Gary,
a L5 radiculopathy due to a herniated disc is an important cause of foot drop. I am not sure about the kind of surgical intervention you underwent. Was it just a disectomy or was there spinal fusion done too. If the nerve root was just pinched, your recovery should be complete. However if the nerve root was crushed, the recovery may be delayed and at times incomplete. I would advise you to follow up with your doctor. Physical therapy is the key and I would be aggressive about it.
Personal Regards,
Nitin Sethi, MD
Hi Dr.Sethi,I seem to have developed a spontaneous unilateral foot drop on my left side. I have had no injuries and I’m not diabetic. I have R.A.(affecting my hands) and have been prescribed a low dose of Prednisone for the past month. I seem to have noticed a vague sense of fatigue in my left lower leg and foot about 2 weeks ago. I thought it was related to my habit of crossing my legs. Also,I’m an RN.and in my sixth month of alcohol addiction recovery.Can you shed some light ? Thank you. Happy new year to you.
Thank you Michelle and Happy New Year 2009 to you too. While there are numerous causes of foot drop some innocuous and some not so, your history suggests that you have compression neuropathy of the peroneal nerve. As you may know compression neuropathies and pressure palsies (nerve damage due to pressure) such as foot drop and wrist drop occur commonly in diabetics. They are also more commonly seen in people who consume alcohol in excess. This is likely due to multifactorial causes: alcohol acts as a neurotoxin especially when consumed in excess over a long period of time. Also people who drink alcohol in excess usually have marginal diets devoid of vitamins which are needed for healthy nerves. It is possible that your past history of alcohol consumption may have contributed to your foot drop. That and the fact that you have Rheumatoid Arthritis maintained on low dose steroids.
My advise to you would be simple. If this indeed is a compression neuropathy, the natural history is one of spontaneous resolution and improvement. Spontaneous improvement occurs over 2-3 weeks and all you have to do is wear a splint so that you do not trip when you walk. I would also advise you to supplement your diet with at least 2 tabs of a good multivitamin per day (Centrum silver may be a reasonable choice). Physical therapy always helps and should be initiated early rather than late.
If the recovery is delayed or poor, then usually 2 weeks after the index event (the time when you first noticed the foot drop), a nerve conduction study may be carried out (NCV/EMG study). This tells us about the extent of nerve damage and the site of nerve compression and thus aids in prognostication purposes.
My advise to you would be to consult a neurologist whose interest includes neuromuscular disorders. Depending upon your history and clinical examination he may or may not order a NCV/EMG study. Also he would be able to determine the etiology of your spontaneous foot drop. One last word, avoid alcohol completely till your foot drop recovers. Also abstain from smoking. Both act as neurotoxins and potentially may delay spontaneous recovery of nerve function.
Feel free to write again if you have any other questions.
Personal Regards,
Nitin Sethi, MD
Dear Dr.Sethi, Thank you for your response to my questions regarding foot drop.( Dec.31) It was very helpful to me. Unfortunately, I can’t pursue a neuro. workup until I have health insurance,which hopefully will be very soon. I appreciate your professional,intelligent replies to your readers here. I’d like to pose another question to you for any thoughts you may have on this. Do you see any relationship to childhood vaccinations and the onset of autoimmune disorders ? Is is true that the numbers of individuals being treated for many of these disorders have been dramatically on the rise ? Thank you again for your compassionate attention.
You are very welcome Michelle. I hope you are able to see a neurologist soon. As for your question about a possible link between childhood vaccinations and auto-immune diseases, this has been looked at closely by the medical community. We know that acute disseminated encephalomyelitis (ADEM) (a type of demyelinating disease which in all probability has an autoimmune basis) may occur in some individuals after vaccination. There are other anecdoctal reports of diseases like Guillain Barre Syndrome (GBS), a demyelinating disease of the peripheral nervous system occuring after hepatitis B vaccination. I want to stress that these are idiosyncratic reactions (meaning there is no good explanation why the vaccination triggers off the autoimmune destructive cascade in some people and hence there is no way of predicting beforehand who these people may be so as to avoid vaccinating them).
The vaccines on the market today have undergone thorough safety studies, they safe lives and protect against some potentially deadly diseases. I feel the press coverage on this has been a little biased focusing only on the vaccines potential risk of causing some autoimmune diseases. In the U.S.A a lot of media coverage has been towards the potential role if any they play in causing autistic spectrum disorder. None of the studies has confirmed that such an association exists but parents are justifiably scared and at times do not vaccinate their children thus exposing them to potentially deadly diseases like measles.
Personal Regards,
Nitin Sethi, MD
Thank you so much for your response.
You are very welcome Michelle, it is always a pleasure to hear from you. Stay healthy Michelle.
Personal Regards,
Nitin Sethi, MD
Dear Dr. Sath,
In late October I fell unconscious on a hard floor for a number of hours. I was diagnosed with compartment syndrome and underwent fascioctomy in my forearm and calf. Currently, I am suffering with a Volkman contracture in my left hand and a severe foot drop in my left foot. Today, I went for my first EMG. The consultant advised that the damage to my nerve was around my hip / buttock area (I was on my side when I came around). I do not know what the prognosis is for this type of injury causing foot drop, and it will be at least six weeks before I get referred to a neurologist. I am worried that as 3 months have passed and no dorsiflexion can be achieved that it may not return at all. I am currently managing with an AFO and attending regular physion sessions. Thank you in advance. Duncan.
Dear Duncan,
thank you for writing in. I understand your concern well. The nerve conduction and EMG study actually shall be of great well in prognosticating purposes. If it shows evidence of nerve degeneration and changes in the muscles supplied, that would imply that the prognosis is guarded (meaning that recovery may be slow and at times incomplete). On the other hand it may show evidence of nerve regeneration which usually translates into clinical recovery. So I feel a well performed NCV/EMG study shall help immensely.
In the meantime, my advise would be to continue with good and intense physical therapy and follow up with a neurologist.
Personal Regards,
Nitin Sethi, MD
dear doctor
i want to know about late recovery of dorsiflexors in G.B. Syndrome. i know few cases in which very good recovery has occured in all muscle of persons suffering from G.B. Syndrome but no recovery took place in dorsiflexors despite regular physiotherapy. why.
please answer
Dear Mr. Mahmood,
Patient’s with GBS usually do make a full recovery. Some though don’t and are left behind with varying degree of motor deficits. The dorsiflexors of the foot are involved early and sometimes the nerve involvement is severe. We refer to this as axonal degeneration (the axons of the nerves degenerate). Normally in GBS there is only demyelination (the myelin gets stripped off the nerves). Pure demyelinating forms of GBS usually show a full recovery but if there is secondary axonal degeration the recovery may remain incomplete. A nerve conduction study (NCV) shall aid in identifying if axonal degeneration has occured and thus help in prognostication purposes.
Personal Regards,
Nitin Sethi, MD
I am wondering what would be a high mm pressure in the lower leg that would indicate the necessity for fasciotomies? Is there a way to determine how long CS has been present based on the mm level/reading of the pressure test? Thanks.
Thank you for writing in. The need for a fasciotomy is a clinical decision made at the bedside. One can measure the pressure but also has to take into account the presence/ absence of distal pulsations and other such variables. The pressure per se does not correlate with the duration of the pathophysiological process.
Personal Regards,
Nitin Sethi, MD
Dear Dr.Sethi, My husband has a foot drop on the left leg. He started limping about a year ago, but even before he had pain and crums in the leg. He went to see an acupunturist, who took out most of the pain and the crums too. He’s just seen a neurologist, who’s done some tests, but said he can’t confirm anything at the moment, it could be a damaged root nerve, – though he never had any accident – or it can be motor neuron disease. He has to go back in 3 months time to repeat the test and to get another MRI. (the first MRI didn’t show anything, but it wasn’t looked at by a neurologist, only by a rheumatologist)
He seems about the same since the last few month, and he just got that brace which helps him in walking.
But am terrified that it could be a motor neuron disease, and I just wish there was something that could exclude this. Could it be a nerve damage without an accident? Thanks
Dear Esther,
thank you for writing in. Foot drop can have many causes ranging from relatively benign ones like a radiculopathy or neuropathy (damage to a nerve root or the nerve itself either due to trauma, herniated disk or compression) to more serious ones such as motor neuron disease.
Get the opinion of a neurologist. He or she shall be able to rule out motor neuron disease relatively easily. I wish your husband my very best.
Personal Regards,
Nitin Sethi, MD
Dr. Sethi,
I am 23 years old and underwent gastric bypass surgery on December 1st, 2008. I have since lost 96 pounds and counting. A few weeks ago, I began to have numbness/tingling in my calves and feet, but I thought nothing of it and dismissed it to a nerve trying to heal from my surgery. But last Friday, I began having trouble walking. I noticed that I was picking my right leg up higher. Then I began falling. I went to the er and the er Dr. got me an appt with a neurologist that day – who diagnosed me with drop foot. He did an emg (didn’t find out much info from that) and then ordered an MRI and Lumbar Punture. I looked up my symptoms online and found something called Slimmers Paralysis. It fits me perfect, but my Dr. has not said anything about it. But after reading your blog, I know now that it could very possibly be from crossing my legs. I was crossing my legs ALL the time. So, if I stop, my drop foot could possibly just go away on its own without surgical intervention? Please help me as I am desperate for answers. This has been devistating to me. I am a very healthy person and this just doesn’t make sense. Thank you for taking time to read this.
Dear Candace,
thank you for writing in. It is most likely that you have a compression neurapraxia (meaning that you compressed your peroneal nerve and that has led to a foot drop). The most likely cause in your case is the rapid weight loss making your nerves more prone to compression. The good news is that, compression neurapraxia has a benign course and nerve recovery is complete over a few weeks.
I would do the simple things. Wear a splint for the foot drop. Ask your doctor to check you for common vitamin deficiencies such as Vitamin B1, Vitamin B6 and Vitamin B12. If you are deficient in any of these, I would advise supplementation.
I wish you my best. Feel free to write in again.
Personal Regards,
Nitin Sethi, MD
Dear Dr. Sethi,
First I would like to thank you for the information that you provide in your blog. I have been trying to research my condition (foot drop) but have been unsuccessful at finding more information other that what it is.
I had surgery about 6 weeks ago and due to compression on the peroneal nerve at the fibula head I have foot drop. Its been six weeks. I saw a neurologist and I am doing physical therapy 2X a week and I wear an AFO. I am getting frustrated and scared because I see no improvement.
My doctors tell me not to worry and that it will get better, however they don’t seem to be concerned and I wouldn’t be either if I saw that I was getting better.
Please let me know what else I can do to recover.
Thank you,
Sylvia
Dear Sylvia,
Thank you for writing in. You do not mention why you had the surgery and what kind of surgery it was. The rate/speed of recovery of the peroneal nerve depends upon the mechanism of injury to the nerve. if you have compression neurapraxia (meaning that the nerve was compressed but the axons are intact), then the nerve usually recovers quickly and the recovery is complete. If on the other hand the injury is either an axonotmesis (the axons are damaged) or neuronotmesis (the whole nerve is completely cut in two) the recovery is slow and it may be incomplete.
A nerve conduction study and electromyogram (NCV/EMG) study shall help in determing what kind of injury you have suffered and shall also help in prognostication.
Personal Regards,
Nitin Sethi, MD
Hi there, great info!
I have had foot drop for about 3 weeks now with my right leg/foot. A nerve conductor study last week showed peroneal nerve damage and the Doctor said it was from crossing my legs. I am getting a brace this week and have stopped crossing my legs. He said the damage wasn’t terribly bad and hopefully will correct itself. Since I have not been crossing my legs, I have seen no improvement. It’s been about a week. He wanted to see me one more time at the end of this week, just to poke me again and make sure.
My question is, should I be satisfied with that answer? Should I move on and request an MRI or something just to be sure?
Dear Lisa,
thank you for writing in. Yes I think you should be satisfied with the answer. The rate of recovery varies depending upon the mechanism of the injury. Read my answer to Sylvia’s question above. I would repeat the NCV/EMG only if the nerve is not recovering within an appropriate time frame.
Personal Regards,
Nitin Sethi, MD
Hi Dr. Sethi,
Thank you for replying so quickly. The type of surgery I had was a vaginal procedure that had nothing to do with my foot. The surgery took longer than expected and the stirrups pressed against my nerve.
Dr. Sethi,
Its me again. I have had and MRI, EMG, Lumbar Punture, X-Rays, and blood work and everything has come back fine. My Dr. has no idea why I have drop foot and Neuropathy. Is there not a way he can see if I have a compressed nerve? I am getting so desperate. I can’t sleep at night because of the pain in my feet and I see no improvement. My Neurologist told me that we are not going to do anymore tests – that we are just going to wait it out and see what happens within the upcoming months. He said that my age (23) and the fact that I am very healthy otherwise, is a good indication that I will make a full recovery. Should I get a second opinion? He did an EMG and all he told me was that my muscles were good and that he didn’t get a good reading from my nerves because of inflamation. I am sorry to both you again, I am just scared to death. Thank you!!
Dear Candace,
if the foot drop is due to peroneal nerve compression at the fibular head then most of the tests shall come back “normal”. Patients usually make a spontaneous recovery over a few weeks time. I would advise you to avoid potential neurotoxins such as smoking and alcohol. Take a good diet and one tab of multivitamin per day and of course physical therapy should continue.
Personal Regards,
Nitin Sethi, MD
Hello there!
I posted awhile back about my problem with foot drop. I have since had a nerve conductor test which found that I have damage on the outside of my knee that pinpointed between above and below the knee. This is from crossing my legs! I have had an office job for 20 years and it finally took it’s toll. I got fitted for a custom brace with springs at the ankle that keeps my foot at a degree where it won’t drop. I can walk normally although it’s kind of a pain in the butt.
He said it would probably take about 4 months or so to correct (or never), but I needed to stop crossing my legs. The nerve grows back very slowly he said and I probably would wake up one day and the problem will be gone. But the brace is good because it corrects the foot from tending to bend inward, which could eventually become a permanent problem.
It has been almost 2 months and I can now move my toes slightly upwards which is promising. I could not do that before no matter how hard I tried.
My suggestion is to get a nerve test, (not fun), then a brace, it really helps. Good Luck!
Dear Lisa,
thank you for the feedback. I am glad you are improving slowly but steadily.
Personal Regards,
Nitin Sethi, MD
I am so pleased to have found these questions and your answers
I have suudenly developed foot drop and saw my GP who has referred me to a neurologist but I can’t get in to see him for four months. I have been tripping myself up and now lift my foot higher to avoid same – what type of splint would you suggest I notice that my foot has started to turn inward. Would a podiatrist or physio be able to help me – I you think four months is an awfully long time doing nothing
Kind regards
Sallie
Dear Sallie,
thank you for writing in. I am glad you found the information useful. Physical therapy is very important and I shall recommend it without hesitation. Usually an Ankle Foot Orthosis/Foot Drop Splint is prescribed. This keeps the foot in dorsiflexion and prevents you from tripping or catching your toe on the ground as you walk.
I wish you a speedy recovery.
Personal Regards,
Nitin Sethi, MD
Thank you for the quick response – I’m off to make an appointment for some physiotherapy now and investigate an Ankle Foot Orthosis/Foot Drop Splint
Kind regards
Sallie
You are very welcome Sallie, I wish you a speedy recovery.
Personal Regards,
Nitin Sethi, MD
Dr. Sethi,
Thank you again for the useful information. I do feel much better about my condition. I only have one more question (I think). : ) Is it common to have Neuropathy pain when you have foot drop? I have tingling/numbness/pain in both feet 24 hours a day. I was wondering if that too would go away on its own. Thanks for your time.
Thank you Candace for writing in again. The neuropathic symptoms which you describe should resolve as your nerve recovers. You mention that you have these symptoms in both feet. That makes me wonder whether you have a foot drop (peroneal nerve palsy) superimposed on an underlying neuropathy. My advise would be to bring this to the attention of your treating doctor. Some basic tests can rule out most metabolic and nutritional causes of neuropathy.
Personal Regards,
Nitin Sethi, MD
Doctor, My name is Ty Holsey from Texas. On April 23rd I suffered the worst injury I have ever faced. I tore my ACL, PCL, ligaments and cartilage in my knee playing basketball. I did this by dislocating my knee. As a result of that I now have drop foot. I just recently received surgery for this which was May 28th 2009. It has been almost two weeks now since surgery and over a month since my injury. My doctor told me my nerves are bruised and it will take several weeks and possibly months before I can move my foot again if at all. I was heartbroken by that information. I have not received a splint yet, I’m supposed to go back to the doctor June 15th to get my staples removed from my knee and to get a prescription for rehab. I have numbness in my big toe and across my foot, however, the numbness does not go all the way up my leg like I hear some other people saying. Is there any kind of encouragement you can give me? I have been praying so much for this to heal and I pray it will. What is your opinion?
Dear Ty,
thank you for writing in. I am sorry to hear what you are going through. It must be indeed tough. Hope is always there. The recovery from the foot drop depends upon the kind of injury sustained by the peroneal nerve. If the nerve was completely transected (cut through and through) then recovery is usually slow and may be incomplete. On the other hand if the nerve was merely compressed/ stunned, it usually recovers though as your doctor told you it may take weeks to months. A good quality NERVE CONDUCTION STUDY may aid in prognostication purposes.
I would encourage aggressive rehab therapy once the staples are removed. The journey may be long but if you work hard enough, the recovery may be excellent.
Personal Regards,
Nitin Sethi, MD
I have a question regarding my situation,
after my surgery on my lower back (L5) the outcome resulted in a foot drop.( Before surgery i had a lot of pain, curled toes and numbness.) Three months after my surgery my foot condition has not improved and i still foot drop have no mobility in my foot. How can I know if my sciatic nerve was pinched or crushed and if there is any hope for improvement of my condition?
Dear Lucy,
thank you for writing in. A well performed nerve conduction study and electromyogram (NCV/EMG) shall aid in prognostication purposes. It shall help your physician in identifying the degree of nerve damage as well as recovery. I wish you my best.
Personal Regards,
Nitin Sethi, MD