Foot drop


The study below tried to compare the clinical effectiveness of ankle-foot orthoses (AFOs) and functional electrical stimulation (FES) and whether or not they were cost effective. The high drop-out rate (38%) made the study inconclusive.

When we, at Barts-MS, did a clinical audit a few years ago we showed that the best predictor of falls was the need to use a walking aid; e.g. walking stick, chair, AFO or FES. Falls in MSers are a major cause of morbidity and in fact mortality and are the 3rd or 4th most common reason why MSers need urgent, or unplanned, hospital admissions. Falls lead to head injuries and frequently cause fractures. For example, in the last 4 weeks, I have seen three patients who sustained fractures as a result of falls; one a fractured scaphoid bone in the wrist, another a fractured ankle and the third a fractured humerus and clavicle.


If you are tripping and/or falling please ask your neurologist or MS nurse to assess you to see if you need a physio assessment to reduce your risk of falls. Prevention is better than having to deal with the consequences of falls.

When it comes to ankle-foot orthoses (AFOs) or functional electrical stimulation (FES) they both do the job equally well. Some people can’t tolerate AFOs (too bulky and unsightly) and others can’t tolerate FES devices (too finicky and/or painful). In addition, to these two options, there is a multitude of other options for MS-related foot drop that are available to you. If you don’t ask you won’t find out.


If you are at risk of falls you need to look into your bone health. This requires a bone density or DEXA scan. MSers are at high risk of having thin bones (osteopaenia or osteoporosis) and may need medication to try and reverse this.

Renfrew et al. The clinical- and cost-effectiveness of functional electrical stimulation and ankle-foot orthoses for foot drop in Multiple Sclerosis: a multicentre randomized trial. Clin Rehabil. 2019 Apr 11:269215519842254. doi: 10.1177/0269215519842254.

OBJECTIVE: To compare the clinical- and cost-effectiveness of ankle-foot orthoses (AFOs) and functional electrical stimulation (FES) over 12 months in people with Multiple Sclerosis with foot drop.

DESIGN: Multicentre, powered, non-blinded, randomized trial.

SETTING: Seven Multiple Sclerosis outpatient centres across Scotland.

SUBJECTS: Eighty-five treatment-naïve people with Multiple Sclerosis with persistent (>three months) foot drop.

INTERVENTIONS: Participants randomized to receive a custom-made, AFO ( n = 43) or FES device ( n = 42).

OUTCOME MEASURES: Assessed at 0, 3, 6 and 12 months; 5-minute self-selected walk test (primary), Timed 25 Foot Walk, oxygen cost of walking, Multiple Sclerosis Impact Scale-29, Multiple Sclerosis Walking Scale-12, Modified Fatigue Impact Scale, Euroqol five-dimension five-level questionnaire, Activities-specific Balance and Confidence Scale, Psychological Impact of Assistive Devices Score, and equipment and National Health Service staff time costs of interventions.

RESULTS: Groups were similar for age (AFO, 51.4 (11.2); FES, 50.4(10.4) years) and baseline walking speed (AFO, 0.62 (0.21); FES 0.73 (0.27) m/s). In all, 38% dropped out by 12 months (AFO, n = 21; FES, n = 11). Both groups walked faster at 12 months with device ( P < 0.001; AFO, 0.73 (0.24); FES, 0.79 (0.24) m/s) but no difference between groups. Significantly higher Psychological Impact of Assistive Devices Scores were found for FES for Competence ( P = 0.016; AFO, 0.85(1.05); FES, 1.53(1.05)), Adaptability ( P = 0.001; AFO, 0.38(0.97); FES 1.53 (0.98)) and Self-Esteem ( P = 0.006; AFO, 0.45 (0.67); FES 1 (0.68)). Effects were comparable for other measures. FES may offer value for money alternative to usual care.

CONCLUSION: AFOs and FES have comparable effects on walking performance and patient-reported outcomes; however, high drop-outs introduces uncertainty.

About the author


Professor of Neurology, Barts & The London. MS & Preventive Neurology thinker, blogger, runner, vegetable gardener, husband, father, cook and wine & food lover.


  • Having used an FES device for some years, my knee started to protest after the years of uneven gait. The physio at the FES centre recommended a Centri Dynamic Walk orthotic. It immediately sorted the knee, preventing hyperextension and because of its slightly upward angle at the toe was as effective as FES had been at preventing footdrop. I had to go several hoops before my own NHS orthotics dept would prescribe it – not for reasons of cost (it’s about £200, I believe) but because they’d never heard of it. It was only because their physio turned out to have done her training alongside the FES physio that she had the conversation and was persuaded. It’s a weightless carbon steel insole with flexible plastic rods extending from the heel to the back of the calf , with a padded thin metal cuff behind the knee. It has transformed my walking and is so very much more convenient and fuss-free than FES.

  • What exactly is meant by AFO here? I thought that orthoses were garments that work something like Kinesio tapes, providing feedback. E.g. with my 2 decades of “PPMS” I find an orthoses in the form of shorts helpful for walking (but sports compression shorts are almost as good).

    I had what the Physiotherapists referred as a splint for footdrop, but it reduced circulation and gave me cramp. It wasn’t theraputic in that it replaced muscle tone, rather than helping rebuild it. On the other hand, I used an FES for some time and it helped me regain function so that I no longer need it.

    • This is the explanation from the methods section:

      “Participants randomized to the usual care group were fitted with a custom-made, solid, ankle-foot orthosis by an orthotist, within four weeks of their initial assessment. The recommendations made by the Best Practice Statement for ankle-foot orthoses following stroke were applied.27 The orthoses were made with 5-mm homopolymer polypropylene, trim lines were anterior to the malleoli and reinforcements added to the ankle section as required. The angle of the tibia was inclined forward, approximately 10° to vertical, and each orthosis was ‘tuned’ by the addition or removal of small heel wedges.”

  • Good article Prof G. I use to trip constantly on the smallest bumps. One reason was one leg was faster than the other. However I consciously decided to change the way I walk by flicking my toes up for every step. Although this works for long distance it’s not a option.

    • It sounds as if you may need a device. The problem with doing what you are doing at the moment is that if you get distracted you are likely to forget to lift your foot and it will catch and put you at risk of falling.

  • What is the meaning of “dropping out”. Do patients simply opt for a wheel chair?

    It’s my impression that orthoses are considered far too rarely when patients pass through EDSS levels 4-6. While the risk of falls is certainly not to be ignored, it should be offset by the additional years of sedentary wheelchair bound life.

    The AFO vs. FES comparisons appear superficial. AFO block calf muscle activity while FES simulate them. The gait of patients whose ankles are blocked by AFO will never resemble those with fine tuned FES calf stimulation.

    Moreover, studies only look at footdrop induced by an impaired peroneal nerve. What about patients with non-responsive hamstrings? FES solutions offer separate stimulation for thighs to lift the knees. What is the AFO equivalent?

    Overall, it appears the potential of good FES solutions is generally undervalued and only correctly leveraged by a select few treatment centers. One of the leading rehabilitation clinics in Germany has a “success rate” of reestablishing mobility with approximately 80% of patients having neurological impairments. One success factor? Systematic screening for possible usage of FES. Why are so few others taking this approach?

    • Re: Dropping out

      Dropping out means dropping out of the study; i.e. they didn’t come back for the follow-up assessment.

      Re: Systematic screening for possible usage of FES. Why are so few others taking this approach?

      I suspect the disincentive here is financial, i.e. the NHS doesn’t have the resources and staff to proactively screen people with MS for assistive walking devices.

  • I tried a carbon AFO, fitted by a prosthetist, for my left foot drop. It helped, but it was uncomfortable. But it was covered by my insurance. (I’m in the US). Then I used the Bioness L300 FES, which you picture. It was better than the AFO. Unfortunately, it was expensive and not covered by my insurance. I appealed the insurance denial twice, using the argument that using the FES would prevent falls. By covering it they would likely saving a lot more than the $3,000 (discounted) cost of the unit by reducing the chance of a fall and a fracture. They didn’t buy the argument. Stupid…stupid!

    But I bought it, anyway. The L300 allowed me to climb a grassy slope using one cane. I got used to the voltage zap each time I lifted my leg, and put up with the nuisance of strapping on the cuff each day and being uncomfortable wearing it for several hours. It was worth it.

    That was about eight years ago. Since then my MS has progressed to the point where I’m using two canes and the L300 doesn’t help as much as it once did. I still use it, however, but I can now walk almost as well, with two canes, as without it. (My left hip flexor, I think, gives me more of a problem than my foot drop).

  • Great post Prof. G.,
    I have both kinds, on both feet from the NHS, and both have good and bad points. My orthotics are blue rockers, carbon fibre and comfy, but straps dig in after a few hours. These always work but I find walking harder than with FES, but my gait is not so good with these now. My FES are ODFS pace models, a bit tricky to set up at first but now easy. Wires can get tangled, electrodes can fall off, and foot switch sometimes a bit sensitive if you change your gait. Main bad point is the faff of putting them on – I use gel to make them stick. Best solution for me us using both together, but it is 40 minutes to set up, and orthotic can move electrodes. I now just use one set or the other, depending on what I am doing. On airplanes I use orthotics which are not comfy fit long flights. My recommendation is to have both and mix and match. Not impressed by FES wireless dongles – more effort that they are worth in my experience, but others live them.

    But I fall over less with fes – it’s not the falling that hurts, of course. But learning to have controlled falls on being able to pick yourself up was something that I had to work on when I set my mind on remaining independent. Clearly, this won’t work for all.

    • Re: “But learning to have controlled falls on being able to pick yourself up was something that I had to work on when I set my mind on remaining independent.”

      Please don’t forget your bone health; DEXA scan and possibly meds to protect your bones from thinning.

  • For those PwMS for whom exercise is possible then Trevor Wicken MS Gym on YouTube has some useful foot drop exercises.
    I’m lucky enough to see a neuro physiotherapist every 6 months. When I first met her about 2 years ago I had pretty bad foot drop. Thanks to the exercises she provided I’m currently free of FD. Also some of the foot eversion movements I find easy to do sitting and watching TV of an evening.
    My physio kindly took a look at Trevor’s MS Gym vids on YouTube and has endorsed what he provides in them for PwMS.

By Gavin



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