One shoe often tells the story first.
The toe is scraped. The rubber is worn down. The other shoe looks almost new.
Then there is the sound: a soft drag across the floor, a foot slap when it lands, or a sudden stumble on a carpet edge that should have been easy to clear.
This is MS foot drop, a gait issue that can occur in multiple sclerosis when ankle dorsiflexion is reduced or poorly controlled during walking [1].
It happens when the front of the foot does not lift cleanly during walking. For people with multiple sclerosis, that small movement can turn stairs, curbs, sidewalks, and crowded spaces into constant concentration tests.
But the important question is not only, “Why is the foot dropping?”
The better question is, “What is happening in the whole walking system that makes one toe start controlling the day?”
The Small Muscle With a Big Job
The tibialis anterior is the muscle along the front of the shin. Its job is to lift the front of the foot upward during walking. This movement is called dorsiflexion [1].
When it works well, the toes clear the floor, and the foot lands in a controlled way.
When MS foot drop interferes with that movement, the body starts finding ways around it.
People may lift the knee higher, swing the leg outward, shorten their steps, stare at the ground more often, or avoid uneven surfaces altogether [1].
These adjustments can help prevent tripping in the moment. But they also take more energy. Over time, walking becomes less automatic and more like a task that needs constant management.
That is why MS foot drop is not just a foot problem. It can affect balance, confidence, fatigue, walking distance, and fall risk [1,2].
Why a Short Clinic Walk May Not Show the Whole Problem
Many people with MS know this frustrating pattern.
You go to the clinic ready to explain the dragging, tripping, or foot slap that has been happening for weeks. Then you walk a short hallway, and suddenly everything looks fine.
After your appointment ends, the foot starts dragging again in the parking lot.
Why is it that this always happens?
A short walking test asks, “Can you walk right now?”
Daily life asks a harder question: “Can you keep walking after heat, fatigue, errands, stairs, stress, and hundreds of previous steps?”
Research on MS walking shows that gait changes can become more noticeable during longer or more demanding walking situations. Even when average speed does not change dramatically, step regularity, stride timing, and walking consistency may worsen over time [3,4].
That is why MS foot drop should not be judged only by a short hallway walk.
Better questions include:
- When does the first toe catch happen?
- Does the foot slap become louder after several minutes?
- Does one knee start lifting higher?
- Does the leg swing outward when fatigue builds?
- How often do near-falls happen outside the clinic?
These details matter because they show how walking changes in real life.
Fatigue and Muscle Fatigability Are Not the Same
In MS, the word “fatigue” can mean many things.
It can mean full-body exhaustion, brain fog, worsening heat-related symptoms, or even sudden exhaustion after feeling completely fine a minute ago.
Researchers often call this perceived fatigue.
Muscle fatigability is more specific. It refers to a measurable decline in a muscle’s ability to produce force after repeated use [5].
This distinction matters because recent PBM research has focused directly on the muscle involved in lifting the foot: the tibialis anterior.
Instead of asking only whether someone “feels less tired,” the study asked whether the muscle could recover force and produce more strength after photobiomodulation.
That is a clearer, more measurable target.
The PBM Study Worth Paying Attention To
In 2024, researchers published a randomized, double-blind crossover study on photobiomodulation and muscle function in people with mild-to-moderate MS [5].
The first phase included 17 participants. After a fatiguing contraction of the tibialis anterior, researchers applied either placebo PBM or active PBM at different doses directly over the muscle.
The high-dose PBM condition showed better force recovery than placebo.
In the second phase, 12 participants used an individually selected PBM dose or placebo for two weeks. After active PBM, average tibialis anterior strength increased from about 162.7 newtons to 185.6 newtons [5].
Put simply, the shin muscle responsible for helping lift the foot recovered force better and became stronger under the tested PBM protocols [5].
This does not mean PBM replaces neurological care or rehabilitation. But it does suggest that the muscle side of MS foot drop may be more responsive and measurable than many people assume.
Why Target the Muscle If MS Starts in the Nervous System?
MS affects the central nervous system. It can disrupt nerve signaling between the brain, spinal cord, and muscles.
But walking still depends on the muscle receiving that signal and turning it into movement again and again.
That is where the tibialis anterior becomes important.
Even if the neurological signal is imperfect, the muscle still needs energy, circulation, recovery capacity, and repeated force production to lift the foot during walking.
PBM research often looks at how red and near-infrared light interact with cellular pathways involved in mitochondrial activity, ATP production, nitric oxide signaling, circulation, oxidative balance, and recovery [6,7].
For MS foot drop, the practical idea is simple:
Support the working muscle so it may perform more consistently with the signal it receives.
Why Whole-Body PBM Is an Interesting Next Step
The 2024 study applied PBM locally to the tibialis anterior. That is important because it gives us a specific muscle story [5].
But MS foot drop does not happen in isolation.
Walking depends on the nervous system, muscle strength, circulation, balance, fatigue, heat sensitivity, sleep, inflammation, and overall physical conditioning.
That is where whole-body PBM becomes an interesting supportive approach.
A whole-body PBM system does not focus only on one small treatment area. It looks at the broader recovery environment around movement, fatigue, circulation, and cellular energy.
For clinics and researchers, this opens a more useful question:
Can targeted muscle findings, like the tibialis anterior PBM study, be connected to broader recovery protocols that support walking function over time?
That is the direction worth exploring.
5 Simple Ways to Track MS Foot Drop Progress
MS foot drop is visible, which means it can be tracked.
Instead of relying only on “I think I’m walking better,” try recording practical changes over time.
- Count toe catches– Track how often your toe catches during the day and what you were doing when it happened.
- Watch shoe wear– Take monthly photos of the top and sole of each shoe. Uneven wear can show dragging patterns.
- Time the first change– Notice how long you can walk before dragging, foot slap, or compensation begins.
- Track near-falls– Include stumbles, trips, or moments where you almost fell but caught yourself.
- Record the context– Write down heat, sleep, stress, illness, exercise, and fatigue level. MS walking changes often follow patterns.
These simple notes can help patients, clinicians, and rehabilitation teams see what a short clinic walk may miss.
One Toe Can Change the Whole Day
MS foot drop may look like one small movement problem.
But one dragging toe can affect walking rhythm, balance, energy use, confidence, and daily independence.
That is why the tibialis anterior study is meaningful. It gives researchers and clinicians a specific muscle target that is directly connected to walking function [5].
The next step is not just asking whether a muscle can become stronger after PBM.
The more important question is whether better muscle recovery can translate into cleaner steps, fewer toe catches, improved walking consistency, and more confidence in daily life.
For people with MS, that is the kind of progress that matters.
Research and Clinical References
[1] Comber L, Galvin R, Coote S. Gait deficits in people with multiple sclerosis: a systematic review and meta-analysis. Gait & Posture. 2017;51:25–35.[2] Abou L, et al. Fear of falling and common symptoms of multiple sclerosis: a systematic review. Multiple Sclerosis and Related Disorders. 2024;84:105506.
[3] Socie MJ, Sosnoff JJ, et al. Changes in gait and fatigue from morning to afternoon in people with multiple sclerosis. Journal of Neurology, Neurosurgery & Psychiatry. 2002;72(3):361–365.
[4] Kalron A, Frid L. Deterioration of specific aspects of gait during the instrumented 6-min walk test among people with multiple sclerosis. Journal of Neurology. 2019;266(12):3022–3030.
[5] Rouhani M, Tolentino M, Lyons JA, Ng AV. Effects of photobiomodulation therapy on muscle function in individuals with multiple sclerosis. Multiple Sclerosis and Related Disorders. 2024;86:105598. doi:10.1016/j.msard.2024.105598.
[6] Ribeiro BG, et al. Systematic review of photobiomodulation for multiple sclerosis. Frontiers in Neurology. 2024;15:1465621.
[7] de Freitas LF, Hamblin MR. Proposed mechanisms of photobiomodulation or low-level light therapy. IEEE Journal of Selected Topics in Quantum Electronics. 2016;22(3):7000417. doi:10.1109/JSTQE.2016.2561201.
