Foot Drop After a Nerve Injury, and Why It Is Not the Same as Foot Drop After a Stroke
We see many people with foot drop, but the cause can vary a great deal and the treatment approach consequently will need to be personalised to the situation. One person has broken a leg; another has dislocated a knee or is recovering from a hip replacement or lumbar spine surgery, and now the foot on that side will not lift. They are catching their toe on every kerb. They have discovered foot drop stimulators online, watched the videos of people walking along a corridor without a brace, and they want to know how to get one.
The videos are genuine. The devices do what they appear to do. But almost every person in those videos has had a stroke, and that difference is not a minor detail. It decides whether that type of device can work for you at all.
I am not a neurologist, and I do not diagnose these problems. Anatomical Concepts supplies and advises on stimulation equipment, and this is a common misunderstanding we hear. So I want to explain what a foot drop stimulator is actually doing, why it may do nothing whatsoever for a peroneal nerve injury, and what does matter in the first few months after that kind of injury.
What the stimulator is actually doing when you walk
A foot drop stimulator is a small unit often worn just below the knee. There are lots of different designs but the principle is the same. It sends short bursts of electrical pulses through the skin to the common peroneal nerve, which passes close to the surface where it wraps around the head of the fibula, the slim bone you can feel on the outer side of the leg. Fire that nerve and the muscles on the front of the shin contract, lifting the foot.
The clever part is the timing of stimulation. A sensor (sometimes a foot contact switch or a "shin tilt" sensor) detects the point in the walking cycle when the foot leaves the ground, and the stimulator fires only during that swing phase. The foot lifts, the toes clear the floor, and the stimulation switches off as the heel lands. It happens on every step, without you needing to think about it
fIt replaces a missing command, not a missing nerve
Here is the part that rarely makes it into the marketing. The stimulator does not create movement out of nothing. It puts an electrical signal onto a nerve and relies on that nerve to carry the effect to the muscle and make it contract. The whole route from the point of stimulation to the muscle has to be intact and conducting.
After a stroke, for example, it usually is. The nerve in the leg is undamaged. What has been lost is the instruction coming down from the brain. The stimulator supplies what we can describe as a replacement instruction, and the intact wiring below does the rest. This is why the official guidance is worded as it is: the relevant NICE guidance is titled "Functional electrical stimulation for drop foot of central neurological origin", and it describes the treatment as being for the effects of upper motor neurone lesions. The words "central" and "upper motor neurone" are doing a great deal of work in that sentence.
A peroneal nerve injury is the opposite situation. The command from the brain is fine. It is the nerve carrying it that has been stretched, crushed or divided. Stimulating above the damage sends a signal into a section of nerve that cannot pass it on to the muscle.
KEY POINT: A foot drop stimulator replaces a missing command from the brain. It cannot replace a missing or injured nerve. If the common peroneal nerve is not conducting between the site of stimulation and the muscle, the device has nothing to work with, and turning the intensity up will not change that.
How the peroneal nerve gets damaged in the first place
The common peroneal nerve is the most frequently injured nerve in the leg, and the reason is anatomical bad luck. Where it curves around the neck of the fibula, it sits close to the skin with almost nothing to cushion it, pressed against bone.
The injuries we hear about most often are:
Direct compression at the fibular neck. A plaster cast or tight bandage, a long operation in an awkward position, prolonged squatting or kneeling, sitting with legs crossed for extended periods, or a long period of bed rest. Significant weight loss can leave the nerve with less padding and make this more likely.
Knee trauma. Dislocation of the knee, ligament injuries, and fractures of the upper fibula.
Orthopaedic surgery. Traction or positioning during hip and knee replacement, and occasionally correction of a knee deformity.
Lumbar spine problems. A compressed L5 nerve root can produce a foot drop that looks identical from the outside, which matters more than most people realise. More on this below.
The reason for listing these is not completeness for its own sake. The cause tells you something about the likely severity of the resulting injury. A nerve that was compressed for a few hours during an operation is a different proposition from a nerve stretched during a knee dislocation, and the outlook for the two is not the same.
Are you sure it is the peroneal nerve?
This is worth raising with your clinician, because the treatment paths diverge if it isn't.
A trapped L5 nerve root in the lower back can cause exactly the same visible problem: a foot that will not lift. But it is a spinal problem, and injecting or decompressing a nerve at the knee will do nothing for it.
There are two clinical signs that help separate them, and they are worth knowing about so you can ask whether they were checked.
The first is turning the sole of the foot inwards, which clinicians call inversion. The muscle doing most of that work is supplied through a different route from the peroneal nerve. So in a peroneal nerve injury, inward turning is usually preserved. If it is weak, that points towards the L5 root instead.
The second is hip abduction, pushing the leg outwards to the side against resistance. This is often the more telling of the two. It is commonly weak in L5 root problems and rarely affected in peroneal nerve injuries.
I am describing these so that you can have a better conversation with your treating physician. Nerve conduction studies and EMG are what settle it, and I have written a full article on reading your own report.
KEY POINT: A foot drop from a trapped nerve root in the back can look identical to one from a damaged nerve at the knee. Weakness when turning the sole of your foot inwards, or when pushing the leg out sideways, points away from the peroneal nerve and towards the spine.
What the outlook looks like
Most people are given no numbers at all, so let me give you the ones that exist.
For closed peroneal nerve injuries, meaning the skin was not opened and the nerve was not cut, published surgical series suggest that around one third recover spontaneously without specific treatment. In the remaining two thirds, some degree of foot drop persists.
That is a mixed message, but of course it is a "rule of thumb" rather than a hard rule. A third is a real chance, and it is a good reason not to despair in the early weeks. It also suggests that for most people, there is a good reason not to simply wait and hope.
In the surgical literature, electrical testing is usually performed three to four weeks after the injury, once the picture has had time to declare itself. Surgery is then considered if there are no electrophysiological signs of recovery at twelve weeks.
Twelve weeks is not a deadline after which nothing can be done, and it does not mean surgery will be recommended in your case. What it means is that around three months there is a decision point at which somebody should be looking at fresh evidence and forming a view, rather than telling you to come back in six months and see how you get on.
KEY POINT: Roughly one in three closed peroneal nerve injuries recovers on its own. The commonly used decision point is twelve weeks: if repeat electrical testing shows no signs of recovery by then, a surgical opinion is worth asking about. If you are approaching three months with no change and nobody has mentioned repeat testing, that is a reasonable thing to raise.
What to do while you are waiting
The waiting period is not empty time, and what you do in it affects what is possible later.
Protect the ankle from stiffening. A foot that hangs down for months will tend to tighten into that position, and a stiff ankle limits what any recovering nerve can achieve. This is because you have muscle imbalance across the joint. Regular movement of the ankle through its full range, and a splint or orthosis that holds the foot at a sensible angle, both matter. If you have been given an ankle-foot orthosis, it is doing a useful job even though it is not treating the nerve or helping muscles get stronger.
Take the falls risk seriously. Catching your toe is how people break wrists and hips. A brace that stops the toe from dropping is unglamorous, but it prevents injuries. There are some devices that are not too bulky and are, of course, easy to use.
Watch the skin. Many peroneal injuries also affect sensation over the top of the foot and the outer shin. Skin you cannot feel properly is skin that can be damaged by footwear without you noticing. Check it.
If you would like to read more about walking safely in an orthosis, we have written about that elsewhere on the site.
Where electrical stimulation does fit
Having explained what a foot drop stimulator cannot do, let me be clear about what stimulation can sometimes offer.
If your injury is partial, and enough of the nerve is still conducting, conventional neuromuscular electrical stimulation may still be able to produce a contraction in the shin muscles. That will not repair the nerve, and it is not a walking aid. What it may do is help maintain the muscle while the nerve regrows, so there is muscle tissue worth reinnervating when the fibres arrive.
We have specialist technology for all types of nerve injury
If the nerve is completely interrupted, conventional stimulation will produce nothing at all, and a different category of equipment entirely is required. That distinction, and how to work out which side of it you are on, is the subject of our main article on peripheral nerve injury and electrical stimulation. We have specialist technology that can help with cases of denervated muscle whether reinnervation is expected or not.
One further point about foot drop stimulators. A meta-analysis by Prenton and colleagues found that functional electrical stimulation and ankle-foot orthoses produce equivalent therapeutic effects on foot drop. The stimulator is not automatically the better choice over a brace.
What I would suggest
If you have a foot drop after an injury or an operation rather than after a stroke, these are the things worth doing, all of them with your own clinical team:
Ask whether your foot drop has been attributed to the peroneal nerve or to the L5 nerve root, and whether inversion and hip abduction were both tested.
If you have not had nerve conduction studies and EMG, ask when they are planned. If your first test was very early, ask whether a repeat is appropriate.
Note the date of your injury and count twelve weeks from it. If you reach that point with no change and no repeat testing arranged, raise it.
Ask what is being done to keep the ankle mobile, and whether the orthosis you have is the right one.
Before buying a foot drop stimulator, ask whether your nerve is conducting well enough for one to work.
At Anatomical Concepts, our role is to help people get the most out of the right rehabilitation technology, assessed and specified for the individual rather than sold off the shelf. In this particular area, that might mean telling someone that the device they had set their heart on is not the right one for their injury, and explaining what would be.
Decisions about your diagnosis and treatment belong with your treating clinicians. What we can do is help you understand what diagnostic test findings mean for the equipment question. This is our expertise.
Further reading
Rasulić L, Nikolić Ž, Lepić M, et al. Useful functional recovery and quality of life after surgical treatment of peroneal nerve injuries. Frontiers in Surgery. 2022;9:1005483. https://doi.org/10.3389/fsurg.2022.1005483
Prenton S, Hollands KL, Kenney LPJ, Onmanee P. Functional electrical stimulation and ankle foot orthoses provide equivalent therapeutic effects on foot drop: a meta-analysis providing direction for future research. Journal of Rehabilitation Medicine. 2018;50(2):129-139.
Bleichner N, Alimusaj M, Heitzmann DWW, et al. Functional electrical stimulation in adults with neurological disorders and foot drop: orthotic and therapeutic effects in short and long term users. Bioengineering. 2026;13(1):71. https://doi.org/10.3390/bioengineering13010071
National Institute for Health and Care Excellence. Functional electrical stimulation for drop foot of central neurological origin. IPG278, January 2009, now HealthTech guidance HTG178. https://www.nice.org.uk/guidance/ipg278
Related articles on our site
Peripheral Nerve Injury and Electrical Stimulation: Which of Three Situations Are You In?
What a Nerve Conduction Study Actually Tells You, and Why It Matters Before Electrical Stimulation
Normal Versus Denervated Muscle: Why the Rules of Electrical Stimulation Change After Nerve Injury