Seven Reasons to Add Stim2Go to the Bike You Already Own After Spinal Cord Injury

FES CyclingStim2Go

23 Sept

Many people have a motorised passive-active bike at home. They use it for a year or two, usually a MOTOmed or a THERA-Trainer, and they use it most days. Their legs go round. The question is whether their legs are getting anything from it beyond going round, and whether the electrical stimulation they saw on the bike in the spinal unit gym could ever come home.

Passive cycling does beneficial things, and adding synchronised electrical stimulation provides a measurable step on top. And the part that has changed recently is that the stimulator no longer has to arrive bolted to a new bike. For many years, we worked with the RehaMove system, which integrated an 8-channel stimulator with a version of the MOTOmed bike. We were always aware that the total cost of the system meant that many people could not adopt it. And as the stimulator needed to communicate directly by cable with the bike, we were restricted to one or two models of MOTOmed. Why should they give up the bike that they were already using and replace it with one that happened to support FES cycling?

Things have changed now with the arrival of Stim2Go. The bike you already own, whatever the make, is the awkward part of an FES cycling system, and you already have it. Let's see whether adding Stim2Go would be worth it.

What a passive bike is already doing for you

Before we look at the case for adding anything, let's consider the machine you have. A motorised bike that moves your legs for you is not doing nothing. A 2019 systematic review by Phadke and colleagues pulled together eleven studies of passive leg cycling after spinal cord injury and found that repeated sessions produced medium to large effects on leg blood flow, joint range, reflex excitability and spasticity. In 2022, Soriano and colleagues measured what ten minutes of passive cycling did in eleven people with cervical injuries: blood pressure, stroke volume and ventilation all rose a little, and the lining of the blood vessels responded better afterwards. People who own these bikes describe the same things in their own words. For example, legs that feel warm, ankles that no longer swell, bowels that behave.

What passive movement does not do is work the muscle. Kakebeeke and colleagues tested this directly in 2005. They found that thirty minutes of passive cycling in ten people with complete injuries produced no measurable change in the force their leg muscles could generate, although six of the ten felt their legs were looser. That is the limit. The circulation and the range are real benefits. However, the muscle is untouched, because nothing is asking it to contract.

KEY POINT: A passive-active bike on its own improves circulation, joint range and, for many people, the 'feel' of their legs. It does not build or preserve muscle, because the muscle never does any work. Everything that follows is about adding that missing piece to the bike you have.

Reason 1: your bike, whatever the make, can now become an FES bike

Stim2go contains movement sensors that can be used to trigger stimulation as required for an FES bike.

Until recently the stimulator was tied to the bike, either by cable, as with the RehaMove, or built into the ergometer, as with the RTI models. If you owned a different bike, the answer was a new bike.

The Stim2Go from Pajunk takes a different route. It is a 185-gram unit that straps to the thigh and contains motion sensors. It identifies the pedal cycle from the movement of your leg and fires each muscle channel at its programmed point in the stroke. Nothing physically connects it to the bike. As far as I can establish, no other commercially available system synchronises stimulation to the pedal cycle without a physical connection to a specific validated trainer. (Hasomed withdrew the RehaMove from the European market at the end of 2023, although its product pages are still live and I still get asked about it.)

So a MOTOmed, a THERA-Trainer or another passive-active bike that you already own can be the base of an FES cycling system. What the bike ideally needs is controllable pedal resistance, so the stimulated contraction has something to push against. In addition, you need secure foot fixation, because a stimulated leg with no sensation will otherwise leave the pedal, and spasm handling, both of which should be built in.

The cheap motorised pedal exercisers sold online will work with the stimulator, but the common ones lack adjustable resistance, don't support the leg properly, and rely on straps that reviewers report break. I would not put a stimulated, insensate leg on one.

Reason 2: the same session becomes exercise instead of movement

The clearest picture of what stimulation adds comes from a 2018 study by Tørhaug and colleagues in Norway. Fifteen people with spinal cord injury did three sessions in random order. They carried out arm cranking alone, arm cranking with their legs moved passively on a bike, and arm cranking with their legs driven by FES on the same bike. In the eight people with injuries at or above the sixth thoracic level, adding passive leg movement raised peak oxygen uptake by 19 per cent over arms alone, and swapping passive for stimulated cycling raised it a further 16 per cent. Passive is good. Stimulated provides more with the same bike and same session length.

In the seven people with injuries below T6, neither passive nor stimulated legs added anything measurable in a single session, so the size of this effect depends on where your injury is. And the fitness gains are task-specific. Hooker's group showed in 1992 that peak oxygen uptake during stimulated cycling rose by 23 per cent after three to four months of training, with no change when the same people were tested on an arm crank. When van der Scheer and colleagues graded the whole literature in 2021, they rated the evidence for aerobic fitness as low. The exercise stimulus in a session is real. How much of it turns into fitness you can use elsewhere is less certain because it depends on how you choose to exercise.

Reason 3: muscle health, which passive cycling cannot give you

This is the strongest reason on the list. The 2021 systematic review by van der Scheer and colleagues covered 92 studies and 999 adults with spinal cord injury. For muscle health, meaning size, strength and tissue quality, they rated the evidence as high, the only outcome in the review to earn that grade.

The size of the gain varies a great deal between people. A 2022 review by Bekhet and colleagues found muscle cross-sectional area increases from under 6 per cent to 75 per cent across 33 studies, averaging around 26 per cent. In a controlled study from Stockholm, Sköld and colleagues measured 1,300 cubic centimetres of new lower-limb muscle after six months of stimulated cycling in men with complete tetraplegia, against no change in a comparison group. And in a 2023 randomised trial from Gorgey's group in Virginia, the participants who spent their first twelve weeks on passive movement training gained muscle only once stimulated cycling was added.

The footnote is that if muscle size is the only goal, stimulated cycling is probably not the best tool. Two reviews, Fenton in 2023 and Dolbow in 2024, conclude that stimulated resistance training of the thigh, with the leg lifting a weight rather than pedalling, produces the largest and most consistent gains in mass. Which is one reason I would rather people owned a stimulator that can do both. A great advantage that Stim2Go brings is that we can augment many forms of exercise with stimulation, taking us far beyond what FES cycling can do.

KEY POINT: Adding stimulation to the bike is the difference between muscle that is passively moved and muscle that works. The evidence for muscle gain from FES cycling is the strongest in the field, graded high across 92 studies, though the size of the gain varies widely between individuals and a stimulator that can also do resistance work such as the Stim2Go provides the potential to do more.

Reason 4: the early window

If you are reading this in the first months after injury, or on behalf of someone who is, this reason matters more than the others. Baldi and colleagues followed 26 people from about fourteen weeks after injury. Those who did no electrical stimulation lost 21 per cent of their lower-limb lean mass and 27 per cent of their gluteal lean mass over the next six months. Those who did stimulated cycling did not lose it, and by six months had slightly more than they started with. A third group who did stimulated contractions without cycling, with nothing to push against, lost muscle much like the controls.

A 2023 systematic review by Ibitoye and colleagues put conditions on that finding. They found that the benefit to muscle and bone was clearest when stimulation started within about three months of injury, at 30 minutes or more per session, three or more times a week, and was kept up. Dudley-Javoroski and Shields showed why the window matters, measuring between 15 and 35 per cent of bone density lost at the knee in the first year alone. Adding stimulation to a bike as soon as possible after injury is a different proposition from adding it three years later.

Reason 5: spasticity and high tone, and what to expect

The evidence on spasticity itself needs a comment because clinicians give contradictory advice about it. The one study that directly compared stimulated and passive cycling was small. Krause and colleagues put five people through a single session of each, at the same speed and for the same time, and found the leg swung more freely after the stimulated session (a 68 per cent improvement on the pendulum test against 12 per cent after passive), while the clinical stiffness score did not change. A 2021 meta-analysis by Fang and colleagues found a reduction in stiffness scores only after twenty or more sessions, and pooled mostly uncontrolled studies. The more recent review, Couper and Smith in 2025, calls the evidence inconclusive. In the van der Scheer review, increased spasticity was itself an adverse event in four of 203 participants. My own experience is that many people feel looser for a day or so after a session, and that this builds with regular use. In seeing hundreds of people over the years, I've yet to find anybody for whom spasms or spasticity absolutely stop them from using an FES bike. Changes to stimulation parameters, passive cycling before engaging FES, and other tactics can be used to manage this problem.

Reason 6: what it costs

When NICE looked at the RT300 FES Cycling system in 2019, the company's own figures were £14,995 for a six-channel leg cycle, £495 for delivery and set-up, £495 a year for servicing and £528 a year for electrodes, all excluding VAT, with an expected eight-year life. The current UK price is unknown to us but is likely higher now. It's an integrated system, so it includes a bike.

If you already own the passive-active bike, you won't pay for that part again. The Stim2Go is around £7,500 at the time of writing, with everything you need, including support to get you going. We don't anticipate annual service and similar costs. We will give a formal written quotation to anyone who asks. Electrodes are a running cost on every system, ours included.

Two things on funding come up constantly. VAT relief depends on HMRC's test of whether an item is designed solely for use by a disabled person, which a programmable stimulator meets more clearly than an exercise bike does, so ask the supplier rather than assuming. Where funding does come from, in my experience, is interim payments in a compensation claim arranged through a case manager, and, occasionally, a personal health budget, where the local NHS team agrees it meets an identified need.

Reason 7: one stimulator that is not only for the bike

Stim2Go can support many types of exercise and augment them with NMES

The last reason is brief because I have covered it in detail before. The same unit that drives the bike can be set up for sit-to-stand practice, for arm and hand exercises triggered by your own movement, for pain, and for transcutaneous spinal cord stimulation, and much more. If your budget will stretch to one piece of equipment, a unit that changes job as your needs change is less likely to end up in a cupboard. The one exception is denervated muscle, where the nerve supply to the muscle has been lost, as in some injuries at the base of the spine and in most peripheral nerve injuries. Standard stimulators used with FES bikes cannot cause that muscle to contract; a different device is needed.

What adding stimulation will not do

There are three claims you might see made for FES cycling that I do not think the evidence supports.

It will not restore walking. No trial has shown that stimulated cycling improves walking compared with passive cycling. Yaşar and colleagues followed ten people with incomplete injuries who could already walk through four months of stimulated cycling and found their motor scores improved, but their walking measures did not reach significance.

It will not reliably rebuild bone in adults. The one study to show a partial reversal of bone loss, Frotzler and colleagues in 2008, required nearly four hours of cycling a week for a year, found the gain only at the knee end of the thigh bone, and reported variation so wide that some participants must have lost bone. The largest controlled trial, Eser and colleagues in 2003 with 38 people, found no significant effect. The one randomised trial comparing stimulated and passive cycling, in children, found no difference in bone. Mohr and colleagues showed a 10 per cent gain at the shin after a year that disappeared once training dropped to one session a week. NICE's own briefing on FES cycling records no change in bone density.

It does not appear to fix blood sugar or inflammation over a realistic course. Small early studies found encouraging signals; the 24-week randomised trial by Gorgey's group found no change in insulin, glucose or inflammatory markers in either arm.

And benefit stops when you stop. Frotzler's follow-up found that a year after people gave up cycling, only 22 per cent of the muscle they had gained was still there. The one person who kept going at two or three sessions a week kept almost all of it. Kakebeeke's group documented fitness gains of over 100 per cent in one person that fell away as the training volume dropped.

KEY POINT: Stimulated cycling is a commitment to exercise, not a course of treatment. The muscle you gain is lost again within a year of stopping, the bone evidence in adults is weak and dose-hungry, and walking is not on the list.

Any cautions

Autonomic dysreflexia is the first concern for anyone with an injury at or above T6. Tawashy and colleagues screened twelve people for a stimulated cycling programme and had to stop or modify training in four of them because of blood pressure responses, two of them severe and appearing within a minute of the stimulation starting. The threshold they used, a systolic rise of more than 40 mmHg or a reading above 150, is a sensible one for a first session, and the Soriano study I mentioned earlier found that passive cycling alone can trigger it too. It is a reason to start with someone taking your blood pressure, not a reason never to start.

Skin over areas without sensation needs checking after every session. In our experience, at the energy levels generated by these stimulators, any redness dissipates quickly once the session stops. People with a pacemaker were excluded from almost every trial. The safety record I have quoted comes from studies that mostly excluded people with severe osteoporosis or a previous fracture around the hip or pelvis, so it says little about them. The one published femur fracture in this literature happened during a maximal strength test with the knee locked at 90 degrees, not during cycling, but the lesson about not loading a fragile bone against a fixed joint stands. And if you have preserved sensation, the stimulation may simply be uncomfortable at useful intensities, which is something to find out at an assessment rather than after a purchase.

In conclusion

If you own a passive-active bike and are wondering about adding stimulation, three things are worth doing with your own clinical team first. Take the make and model of the bike and your injury level to your physiotherapist or spinal unit and ask directly whether stimulated cycling is appropriate for you. You can check with your clinical advisers or us about any contraindications to using stimulation. And if you were sent home and started to use a bike recently, ask the question now rather than later, because in our experience starting active exercise early is the best option.

What we do at Anatomical Concepts is assess before we recommend: a conversation about your injury and your goals, a look at the bike you have, a trial session on it where practical, and, if it makes sense to go ahead, setting the stimulation programmes to your legs and your bike's spasm settings, training you or your carer to run it, and a follow-up visit after about six weeks. For people who do not have a bike, the THERA-Trainer Tigo models are the ones we typically supply and train on, but a large part of the point of this article is that you can use other models of bike too.

Decisions about treatment sit with your clinicians, and I would always rather you went to them first.

If you would like to talk it through, with no expectation that it leads to a purchase, please get in touch. Sometimes the answer is that your bike and a stimulator would suit you well. Sometimes it is that something else should come first. Either is a useful answer.

Seven Reasons to Add Stim2Go to the Bike You Already Own After Spinal Cord Injury

What a passive bike is already doing for you

Reason 1: your bike, whatever the make, can now become an FES bike

Reason 2: the same session becomes exercise instead of movement

Reason 3: muscle health, which passive cycling cannot give you

Reason 4: the early window

Reason 5: spasticity and high tone, and what to expect

Reason 6: what it costs

Reason 7: one stimulator that is not only for the bike

What adding stimulation will not do

Any cautions

In conclusion

Further reading

Related articles on our site

Anatomical Concepts.
Every Body Better.

Seven Reasons to Add Stim2Go to the Bike You Already Own After Spinal Cord Injury

What a passive bike is already doing for you

Reason 1: your bike, whatever the make, can now become an FES bike

Reason 2: the same session becomes exercise instead of movement

Reason 3: muscle health, which passive cycling cannot give you

Reason 4: the early window

Reason 5: spasticity and high tone, and what to expect

Reason 6: what it costs

Reason 7: one stimulator that is not only for the bike

What adding stimulation will not do

Any cautions

In conclusion

Further reading

Related articles on our site

Two Levels at Once: Stimulating the Neck and Lower Back Together

Anatomical Concepts.Every Body Better.

Anatomical Concepts.
Every Body Better.