What is ALS?
ALS — in full amyotrophic lateral sclerosis — is a slowly progressing disease caused by the gradual destruction of the nerve cells (motor nerves) supplying the voluntarily controlled muscles. The disease typically starts in the limb muscles distant from the trunk and then gradually spreads toward the center.
The process proceeds in steps:
- Muscle strength decreases
- Muscles begin to waste away (atrophy)
- Eventually paralysis develops
- Increasing muscle stiffness (spasticity) and contractures (shortening of the tendons)
- Pain arising from these problems
Quality of life is primarily determined by the progression of muscle weakness. Today the disease is not yet curable by causal therapy, but its symptoms can be slowed and alleviated. Physicians may prescribe drug therapy, and movement therapy and muscle stimulation are of outstanding importance.
Key point
Treatment of ALS relies on three pillars working together: drug therapy + regular physiotherapy + functional electrical stimulation (FES). The peculiarity of FES is that it must adapt to the changing stages of the disease: in early stages classic EMS/NMES is appropriate, while in advanced (denervated) stages selective stimulation is needed. For that reason it is worthwhile to choose a versatile device that provides both.
The three pillars of ALS treatment
The disease requires regular interventions in three areas — together these provide better clinical outcomes:
Medication prescribed by the neurologist is a tool to slow disease progression. Appropriate drugs can moderate disease advancement and treat symptoms (spasms, pain, spasticity) at a symptomatic level. Regular follow-up by the treating physician is essential — both for efficacy and for monitoring side effects.
The more you "neglect" movement, the faster muscle condition can deteriorate. Many people misunderstand what physiotherapy means: IT IS NOT the 10–15 minutes of movement that takes place in the presence of the physiotherapist. The essence is regular repetition at home.
Your physiotherapist will show and teach you movements and exercises suited to your current condition. Every few weeks — taking changes in your condition into account — the exercises to be performed will change. Therefore you need regular consultations.
Home frequency: at least 3–4 sessions daily, each session at least 5–10 minutes. More is better. Without regular movement the muscle condition deteriorates quickly.
Most Hungarian-language medical information sites do not even mention functional stimulation (FES) — yet it could be used successfully if physicians and patients were informed about it.
FES is an electrotherapy method, in essence muscle stimulation, aimed at restoring a specific function or, in the case of ALS, preserving it for as long as possible. Properly applied muscle stimulation according to clinical practice can delay the spread of muscle weakness, relieve stiffness, reduce pain, support urinary and fecal continence, and aid respiratory muscle function.
The combination of FES + physiotherapy yields better results.
Why is ALS stimulation special? – The changing stimulation needs
In ALS the muscle-nerve connection is damaged in a time-varying manner. This is one of the most unique features of the disease and determines what kind of stimulator you need:
| ALS stage | Condition of the motor nerve | Appropriate stimulation | Waveform |
|---|---|---|---|
| Early stage | The nerve is partially functional — muscle weakness and early spasticity are present | Classic EMS/NMES or ETS (synchronized with voluntary attempt) | Biphasic square-wave |
| Intermediate stage | Some muscles' motor nerves are already partly/fully damaged, others remain intact | Both are needed — different program per muscle | Biphasic square + selective (triangle/trapezoid) |
| Advanced stage | The muscle has become denervated and does not receive nerve impulses | Selective stimulation (denervated stimulation) | Long-duration triangular or trapezoid pulses |
Initially NOT selective current! But later it is
At the beginning of the disease, when the motor nerve is still partially functional, ALS corresponds to a central-type paralysis. At this stage you need classic biphasic square-wave EMS/NMES, NOT selective current. Applying selective stimulation to an innervated muscle is unpleasant, painful, and can increase spasticity.
However, as ALS progresses and individual muscles become denervated, THEN selective stimulation becomes the appropriate response. This is assessed by a physiotherapist or neurologist (with EMG testing, time/intensity diagrams), and the stimulator's program should be changed accordingly.
Therefore it is worth choosing a versatile device that provides both types of stimulation. Detailed explanation in the selective stimulation (denervated muscle) pillar article.
Why is a cheap "store-bought" three-thousand forint stimulator not suitable?
Commonly available, inexpensive muscle stimulators mostly deliver a simple square-wave impulse. These are designed for healthy muscle. A muscle supplied by a diseased motor nerve requires very precise impulses, which only a high-quality, medical-grade device can provide. With a poor-quality impulse you are more likely to do harm than good — it's like trying to crack a nut with a 10 kg sledgehammer.
How does FES help manage ALS symptoms?
FES can support people living with ALS in multiple ways. The overview below is worth browsing according to your current symptoms:
Properly set functional stimulation relaxes muscles. It mitigates or at least reduces spasticity and involuntary muscle twitching. These involuntary twitches can occur spontaneously at any time and are especially disturbing if they occur just as you try to initiate a deliberate movement.
Important: stimulation must be adjusted to your condition, the specific muscle, and the treatment goal. Different settings produce relaxation or strengthening — you cannot affect all your muscles identically with the same impulse (or the same program). Modern muscle stimulators have menu systems: after selecting a muscle-relaxing program you can choose the treatment area (forearm, upper arm, trunk, abdomen, glutes, thigh, lower leg) from a list.
Intensity: for muscle relaxation it is enough if the treatment causes barely perceptible twitches — a visible contraction is not necessary. Increasing intensity raises efficacy, but NEVER exceed your pain threshold.
Duration: clinical studies applied stimulation between 60 and 120 minutes daily, divided into several shorter sessions. As a general principle: treat a muscle group (e.g. thigh) for at least 25–30 minutes and at most 90 minutes per day. Preferably in 2–3 short sessions rather than one long session.
When the muscle still has innervation and voluntary movements are possible, you should perform stimulation NOT passively (not only while sitting) but together with the muscle’s characteristic movement through the fullest possible range of motion.
For example, if you are treating the forearm flexors (which assist wrist movement), feel the stimulation and move your wrist through the maximum available range. Bend your wrist as far as you can, then release it during the stimulation pause.
This is beneficial because stiffness is reduced and muscles and tendons relax, allowing pain-free and larger movements. If you stretch muscles and tendons passively (without stimulation), for example by pressing down with your other hand, you may cause micro-injuries that increase stiffness in the long run.
Even in severe ALS it is important to relax joints and muscles. Easier-to-move joints help caregivers position you properly and thereby help prevent pressure sores.
Simply reducing spasticity can make your muscles feel stronger — even before you carry out explicit strengthening treatments!
Another role of muscle stimulation is “teaching” the muscles. Regular stimulation improves the coordinated functioning of muscle fibers and the synchronization of fibers involved in contraction. Stimulated muscles can work more efficiently and precisely, so your movements may become more effective.
Beyond muscle relaxation, it is important that strength-increasing stimulation is planned so you perform it, whenever possible, combined with voluntary movements. Treatments can improve muscle strength, increase resistance to fatigue, and improve coordination.
As long as mobility is preserved, respiratory infections are less frequent. However, if you become confined to a wheelchair or bed, or your trunk muscles are affected, the sitting or lying position compresses the chest. You cannot breathe properly, which significantly increases the risk of respiratory infections.
Weakness of the muscles that move the chest also impairs coughing and hinders airway clearance. One of the most serious problems in ALS is the reduction of coughing ability — therefore FES can be used to assist coughing and to help keep the airways clear.
Strengthening and relaxing the abdominal and trunk muscles can improve breathing for several reasons:
- Looser muscles allow greater chest movement (facilitating lung expansion during inhalation).
- Better coordination of expiratory muscles contributes to improved gas exchange.
- A stronger cough helps clear the airways and may reduce the risk of respiratory infections.
There are also several belt-like accessories available for stimulators that are simply placed on the abdomen or back and simplify treatment.
Pressure ulcers commonly develop in areas exposed to prolonged pressure. Many factors play a role: stiffness, joint contracture, immobility due to paralysis, and circulation impairment caused by pressure on the surface.
Functional stimulation can reduce your risk:
- Reducing stiffness — helps you change positions more often and achieve better positioning.
- Increasing muscle mass — improves "padding," reducing direct pressure on the bones and distributing pressure on the skin more evenly.
- Improving blood circulation — muscle contractions can increase blood flow to the treated area, contributing to skin oxygenation.
If a pressure ulcer does develop, FES can speed up the healing process. Improved blood flow enhances oxygen supply to skin and muscle, which can accelerate connective tissue and scar formation and minimize infection. Healing chances are better the more superficial the layers affected are; the deeper the wound, the slower and more difficult the healing.
With ALS progression, pelvic floor sphincter muscles may also weaken, resulting in incontinence symptoms. Special stimulation of the pelvic floor muscles (via probe or surface electrode placement) can support urinary and fecal continence. This should be planned and initiated exclusively by a urologist, gastroenterologist or physiotherapist specialist — with an appropriate protocol that can be continued at home.
Which device is suitable for people living with ALS?
In ALS the appropriate type of stimulation changes as the disease progresses. Therefore you can choose between two strategies:
- Versatile, "do-it-all" device — a single device usable throughout the disease course (classic EMS + selective stimulation in one).
- Pairing specialized devices — an early-stage device (ETS or classic NMES) + a late-stage device (selective).
Strategy 1 is generally preferable in ALS because you won't need to buy a new device later.
Strategy 1 – Versatile devices (highlighted ALS recommendation)
These devices provide selective stimulation AND classic NMES — so they can be used in both phases of the disease:
Genesy 3000 – professional-level versatile device
The top of the Globus Genesy line. Selective stimulation programs for denervated muscle treatment + extensive NMES programs for training innervated muscles and rehabilitation. Usable throughout the ALS disease course with numerous clinically documented protocols. 4-channel, professional level.
Genesy 1500 – top home-level device
A high-end member of the Genesy line adapted for home use: provides selective stimulation programs AND broad NMES functionality. A suitable choice for ALS because it can be used throughout the disease course — no need to change devices later.
Genesy 600 – entry-mid-range versatile device
The Genesy line’s entry-mid model: contains selective stimulation programs AND NMES functionality. A cost-effective choice for people living with ALS when used according to a physiotherapist’s protocol.
Strategy 2 – Stage-specific devices
In the early stage (intact or partially intact motor nerve):
DuoBravo N – ETS specialist (preferred early-stage choice)
ETS (EMG-Triggered Stimulation) technology can be especially valuable in early-stage ALS. Stimulation is triggered by the patient's voluntary attempt — the coordination of voluntary movement plus stimulation supports motor learning and maintenance of muscle strength. It DOES NOT include selective stimulation programs, so it is insufficient in advanced stages.
Genesy 300 Pro – classic NMES (early stage)
Classic NMES device, specifically suitable for early ALS. It DOES NOT include selective stimulation programs NOR ETS functionality — it will not be sufficient in the denervated phase.
In advanced stage (denervated muscles):
PeroBravo – selective stimulation specialist
In advanced ALS, when some muscles become denervated, the PeroBravo with its advanced, specialized configuration options is particularly suitable for selective stimulation. Triangle, trapezoid and square pulse programs for individual denervated muscles with adjustable parameters. Detailed explanation in the selective stimulation (denervated muscle) pillar article.
Recovering lost muscle strength (EMS rehab) → Frequently asked questions
As soon as possible after diagnosis. Muscle condition deteriorates rapidly as the disease progresses — earlier initiation of stimulation may help maintain muscle strength, mobility and quality of life for longer. After neurologist consultation, a physiotherapist can help set the initial protocol.
At the onset of ALS the motor nerve is still partially functional — the muscle is in an "innervated" stage. Selective stimulation (long triangle/trapezoid impulses) on an innervated muscle causes unpleasant, even painful sensations and can increase spasticity. Classic biphasic square-wave EMS/NMES is appropriate. When the muscle truly becomes denervated (motor nerve destroyed), THEN you may switch to selective stimulation — this is determined by EMG testing by a physiotherapist or neurologist.
Clinical studies applied stimulation between 60 and 120 minutes per day, divided into several shorter sessions. General guideline:
- One muscle group (e.g. thigh): minimum 25–30 minutes per day, maximum 90 minutes.
- For multiple muscle groups: total daily time can be 1–3 hours.
- Divided into parts: 2–3 sessions daily.
The exact protocol should always be determined by your physiotherapist based on your current condition.
No. FES complements physiotherapy, it does NOT replace it. The two methods together can yield better results than either alone. In fact, the best outcomes are achieved when FES is performed in combination with voluntary movements — for example, while the stimulator treats the forearm muscles, you actively try to move your wrist.
Not recommended. Cheap (3–10k HUF) muscle stimulators are designed for healthy muscle and deliver a simple square-wave impulse. ALS-affected muscle, where the motor nerve is damaged, requires very precise impulses. A poor-quality impulse can be harmful. Choose a medical-grade, professional device (such as the Genesy line or the PeroBravo).
Realistic expectation: FES is not a causal treatment for ALS — it does not eliminate or stop the underlying disease. What it can achieve is delaying the progression of muscle weakness by maintaining muscle mass and tone, reducing stiffness, decreasing pain, and improving respiratory and coughing function. Clinical trials have documented these quality-of-life–improving effects. Preserving quality of life and functional ability in ALS is of key importance.
Before you start treatment
FES is generally safe in ALS, but there are conditions when it should not be applied. Always consult your treating physician or neurologist before starting treatment!
When should you be cautious?
- Implanted pacemaker or defibrillator – electrical impulses may interfere with the implanted device
- Selective stimulation at the BEGINNING of the disease – unpleasant on innervated muscle, increases spasticity
- Active cancer at the treatment site – electrical stimulation should be avoided over the affected area
- Pregnancy – gynecological specialist consultation required
- Epilepsy – electrical stimulation may provoke seizures (relative contraindication; specialist consultation required)
- Skin inflammation or open wound at the electrode site – electrodes must not be placed on damaged skin
- Thrombosis, thrombophlebitis at the treatment site – muscle contraction at the affected area may be dangerous
- Severe sensory loss at the treatment site – increased caution required (you may not feel possible skin irritation)
- Severe cardiovascular disease – uncontrolled high blood pressure, recent myocardial infarction
- Use of cheap, industrial-quality stimulators – the diseased nerve needs precise impulses; a simple stimulator is not suitable
Adjunct treatment, not a standalone therapy
Home FES is an adjunct to ALS rehabilitation and does not replace specialist neurological care, medication or physiotherapy. Diagnostics, treatment planning and monitoring are always carried out by professionals. A detailed contraindication list is available in the electrotherapy contraindications article.
Summary – Quick overview
Sources
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