Denervated muscle rehabilitation with the RISE Stimulator
Introduction to the RISE Stimulator
We are finding there is a growing interest in using electrotherapy to treat denervated muscle. There are many clinical benefits of doing this and given equipment like the Stimulator RISE, it is very easy to do. Clients can do this safely at home given guidance and support.
Denervated muscle refers to a muscle that has lost its nerve supply or connection to the nervous system. Nerves play a crucial role in controlling muscle movement and function by sending electrical impulses to the muscle fibers. When a muscle becomes denervated, it loses this connection, which can lead to muscle weakness, atrophy (shrinkage), and even loss of muscle function over time.
This can occur as a result of various conditions or injuries that damage the nerves supplying the muscle, such as spinal cord injury, stroke, peripheral neuropathy, or certain neuromuscular diseases. Electrical stimulation is one treatment option that can help to restore muscle function in denervated muscle by providing artificial electrical impulses to stimulate the muscle fibers.
The video below is from Anatomical Concepts DIrector Derek Jones who describes the rationale and process of using the RISE Stimulator in some detail. You can review the video and the transcript is shown below
Video Transcript - Training Protocols with the Stimulator RISE
Hello, this is Derek Jones from Anatomical Concepts. In this video, we're going to take a look at the new stimulator RISE and how to use it. And in particular, we're going to be focusing on operation with denervated muscle.
The new stimulator RISE has replaced the original stimulette Den2X unit both products were from Dr.Schufried Medtechnic in Austria, and were created for electrotherapy of denervated muscle. What we've found is that the Stimulator RISE. Has a much nicer user interface and some additional features that make the product somewhat safer and easier to use.
So called denervation injuries matter because of their effects on muscle tissue. There's a loss of muscle bulk over time and a loss of tissue quality. And this can result from an injury to the spinal cord or to a brachial plexus, or indeed any of the peripheral nerves.
What we know is that when untreated, denervated muscle will lose bulk with connective tissue and fat, there's a loss of mitochondria and there is a loss of the muscle's ability to contract with serious long-term effects that damage skin, circulation and bone health.
Not so many years ago, you could have quite reasonably questioned the value of electrical stimulation for cases of complete denervation. However, extensive research has shown that the muscle structure can be preserved or indeed restored with electrical stimulation and that has excellent longterm health benefits.
It will result in reduction of complications and improved appearance. When there's a potential for re-innervation, the muscle structure will remain capable of contracting because you're preserving the structure of both the muscle and the nerve.
In the past, parts of Europe such as Austria for a long time successfully used electrotherapy to treat denervated muscle. In many other countries there was some concern about the safety and the efficacy of trying to do this. The RISE study was a multinational multicenter and 10 year long study, that showed that it was possible to safely and successfully rescue completely denervate d muscles . Particular protocols and specially designed equipment were used. I'm not going to give you a review of the history of electrotherapy, but there are a couple of things that we should revisit in order that we can better understand some of the terminology that I'm going to touch on in describing the waveforms from the RISE unit.
I don't want to spend a lot of time going into the technical details of electrotherapy, but there are a couple of terms that we will use to describe the effect on muscle of different types of wave forms. One of those terms is Twitch and the other is Tetanic and basically by varying the character of the stimulation it's frequency, how long the pulses last and the height the magnitude of each pulse, then we can have different effects on the muscle. Also, the type of wave form will have an effect. Typically whether the wave form is rectangular in form or whether it has a ramp type of appearance. When we're working with denervated muscle, we're interested in producing two types of muscle contraction, as I've said, Twitch contractions, and Tetanic contractions using wave forms of these types.
If you refer to the wave form on the left, you'll see thatit has a frequency of approximately two Hertz, the wave form on the right has a frequency of approximately 20 Hertz, but notice the pulse widths. In both of these wave forms, the pulse widths are of the order of milliseconds. This is because we're working directly to make muscle fibers contract.
If we were working, let's say with conventional. FES where the nerve structures are intact. We would be using pulse widths of microseconds. These pulses are significantly longer because they must work directly with the muscle fibers. Something else to consider is that pulses are not delivered in one continuous train, they're delivered in modulated bursts.
The pulses build up, are sustained and then decay. And then there's a surge interval when pulses are not delivered at all,.We can take a look at the essence of the protocol for using the RISE stimulator. If you like, we have two goals in mind. The first goal is to improve the excitability of the muscles and the second goal is to strengthen and develop the muscle. Obviously the first stage goal improving the excitability of the muscles is necessary simply because denervation will have affected the nerves and the structure of the muscle. So that over time that muscle will tend to lose its ability to contract that's why emphasis is placed on reversing that. By working with Twitch contractions, we're able to encourage the nerve and muscle structures to normalize and be capable of contracting again.
Once we have helped the muscle structure to reorganize and restructure we can strengthen and develop that muscle and that's where we can improve the overall muscle bulk and tissue quality, which is what will reduce the risk of long-term complications and lead to improved appearance. Strengthening and developing the muscle is done with these tetanic contractions. A tetanic contraction is one where we're encouraging a sustained and strong contraction of the muscle and that builds its strength. You'll note here that we're referring to den120 and den40.
Now these are just particular descriptions that are used within the RISE hardware to describe the wave forms for eliciting twitch or tetanic contractions. What's really nice about the RISE hardware is that the developers have taken the outputs from research and mapped the most important waveforms to particular keys on the hardware so that you and I can touch a key and have the wave form available for you straight away. So for example, if we want to access the den120 form, which will produce a twitch contraction in the muscle, we can use PS one or PS five - the difference between those two keys being actually the length of the session.
In the same way. If we wanted to access the den40 protocol, which is about producing a tetanic contraction in the muscle, again, we have that at the tips of our fingers. I should point out though that whilst these keys are pre-programmed with starting values, we may quite often have to adjust the values to suit the individual case to some extent. So if we take a look at what the RISE screen looks like on the left-hand side, we can see an image showing that the wave form PS one has been selected.
We see a summary of the wave form parameters on the left and the session length shown at five minutes. If we press PS one again, we have an ability to make greater detailed changes. This is great when we're assessing or determining a program for an individual. Once we've determined the program, of course, the whole unit can be set in what's called home user mode so that the user can't make settings accidentally.
So to summarize this part, we've described how the den120 waveform produces a Twitch contraction in the muscle and that's responsible really for restoring the tissue its ability to contract as well as the nerve structure - and den40 waveforms are responsible for strengthening what has been recovered. Now ideally, we want to use both the emphasis in the beginning tends to be with den120 and switching to den40 over a period of time. So we'll strengthen what has been recovered over time.
Quite often people think of small electrodes being used with functional electrical stimulation the placement and size of those, perhaps not being critical because you're relying on the intact nerve structure to make the muscle contract. However, with denervation, it's important to cover as much of the muscle as possible without the electrodes touching or overlapping. We're never going to be using adhesive electrodes, we use a conductive rubber and wet sponge combination, and we use the largest electrodes that we can placing them on the part of the body so that they're not touching, but covering as much of the effected muscle as possible.
The placement of electrodes can look a little unusual. Here we see on the left placement being used on the lower leg with two possible combinations. In one situation, one electrode is placed on the pretibial muscles and on the dorsum of the foot and in the other leg, we can see the electrode is placed on the calf muscle and on the plantar surface of the foot.
On the right we can see large electrodes, the sponge and carbon rubber combination being used on the thigh muscles. So here is an example of a twitch contraction protocol. You can see one electrode placed on the pretibial muscles and the second one on the dorsum of the foot. And you can see the Twitch effect, which is influencing the whole of the lower leg and the intrinsic foot muscles.
In this view, you can see the Twitch contraction effect with two large wet sponge and carbon robot electrodes placed on the thigh and the den120 protocol at work. And here's an example of stimulation of the calf and under surface of the foot. In each case it's really important to have good contact with the tissue and the blue elastic wraps are being used for that purpose.
Now, after a period of using the den120, the Twitch protocol, to reconstruct muscle and nerve, what you've done is you've increased the excitability of the muscle so that it can now be strengthened using the den 40 or similar protocols and using the den 40 protocol to produce a strong muscle contraction means that you can progress to carry out resistance training using ankle weights, for example, on a number of repetitions to develop strength over time.
Here's a less typical example of denervated flank muscles. In this case, two large electrodes are placed over the affected muscle tissue with the elastic wrap, holding those in place. So largely the principles are very much the same as the examples we've seen up to now. In the case of brachial plexus injuries, we suggest using something like this shoulder wrap to keep the electrodes snug and in place against the muscle tissue.
One important factor in electrotherapy is the dose to use - how often, what type of wave forms and how intense. It's difficult to be precise about this because not every combination of frequency and intensity has been researched -that being the case we tend to stick with, what's been researched. And then we vary the advice based on the user's response in practice.
As an example of a stimulation approach this slide looks a little complicated, but let me summarize it by saying that at the beginning, what we're aiming to do is make the muscle more responsive and we're going to be using Twitch stimulation. Over time, as the muscle [00:16:00] becomes more reactive, we want to make that muscle larger and stronger so we'll be using to tetanic stimulation.
In the long-term we can either keep going or reduce the amount of time and effort it takes to so we can preserve what is being gained. We generally are advising clients that we'll need to spend at least five days per week per muscle group. Ideally.
This slide elaborates on the stimulation plan and protocol. Im not going to talk through all of this, if you would like a copy, just contact us and we'll arrange for you to have this as a download.
The RISE system is really easy to use the stimulation parameters built into it are based on research. We have to [00:17:00] modify them to some extent to suit a particular individual, but the process works if you stick to it.
The most important factor, especially in the early days of application is just to use the system five or even six days per week. Asking for help and getting reviews, certainly at six month intervals is a good step to take. To support users of this product we have a range of setup notes, assessment forms, and so on that can be deployed. If you need anything, just ask and we'll be happy to help. If you'd like any further information about the RISE stimulator or indeed any of the other products that we deal with, please contact us at the address above either by email or phone, love to hear from you.