Electric Stimulation (EMS)

Introduction
It should be known that I (Chad) had been hooking people up to TENS for 14 years in my physical therapy practice, before I really understood the full rehabilitation potential of EMS. Before coming across the electric stimulation protocol that I use now, I had been using TENS for pain and EMS for patients with nerve damage. Around August or September of 2013, I got really interested in the capabilities of electric stimulation physical therapy for strengthening; I had just read the Charlie Francis training system, found at charliefrancis.com, where Giovanni Ciriani was posting a lot of how-to EMS information, along with having just read the two-part review papers in the Journal of Strength and Conditioning Research on EMS parameters for strength, and EMS for athletes. When reading the research, there were no long term studies with EMS for strength and fitness in normal subjects, with the longest being in the ballpark of 8-12 weeks (generally successful). There were some studies longer than a year, but they were done with spinal cord injury patients (again generally successful), so I figured why not quit lifting weights for a year and try electric stimulation instead?

I knew it wouldn’t be a controlled study and would have a large potential for confounding variables and potential for bias, etc., but I had never heard of anyone doing the same. This way, I figured it would at least give me a general idea of what the new machines were capable of. I also figured that this experiment would help me help others with its’ use. I was able to work through the practical problems of training all major muscle groups with EMS, and help determine what I thought were the best electrode placements, parameters, machines, accessories etc. Being a physical therapist or other rehabilitation specialist without extensive experience regarding what different parameters are, and knowing what they feel like, is like teaching exercise when you don’t even work out.  I know what I know largely because I committed to EMS as my only form of strength training for a full year. Next to exercise, electric muscle stimulation is by far the most effective modality available to physical therapists. If you are a physical therapist and you don’t agree, it’s because you don’t know how to use it. Applied properly, it’s immediately obvious; as Terence McKenna would say, “It doesn’t require any faith.”

 

Conditions EMS is commonly used for in our clinic:

  1. Low Back Pain
  2. Neuropathy
  3. Headaches
  4. Tendinopathy
  5. Plantar fasciitis
  6. Fibromyalgia
  7. Rheumatoid Arthritis

 

Why We Use EMS Instead of TENS

Back Pain

Studies that have compared EMS (parameters designed to increase muscle strength) with TENS (parameters designed to decrease pain) show that the EMS parameters do more to decrease pain. TENS works by gate control theory and is more effective with increased intensity, while EMS, which by nature is more intense than most recommended TENS parameters, should work better. Additionally, these parameters allow for strengthening to occur simultaneously with pain relief.

I think the most intense core strength exercise is done with electric muscle stimulation, which if done properly not only increases muscle strength better than you can with curl ups or planks, but also does a real good job of acutely reducing back pain. I get a lot of results with short term pain reduction and strengthening of the core muscles by using EMS if it is too painful to do regular core exercises. Usually though, I have my patients do both EMS and exercises. Squats and deadlifts, if performed keeping the spine neutral, are two of my favorite spine stabilization exercises.

Check out Chad’s blog to read more about Why We Use EMS Instead of TENS.

Neuropathy

Another study that supports my reasoning towards the use of  EMS vs. TENS, comes from an experiment where researchers were evaluating the efficacy of transcutaneous electrotherapy for chronic painful peripheral neuropathy in patients with type 2 diabetes.  This study didn’t look at function, but rather attempted to lessen/eliminate pain in patients with the painful form of neuropathy (some patients don’t hurt but only have numbness). As noted in the abstract, 83% of those treated with electric stimulation improved and 17% became completely asymptomatic.

My treatments are shorter in duration using biphasic square waveforms and EMS patterns designed to increase strength, but my patients report pain relief similar to the above researchers. The 35 mA used in this study I expect will decrease pain, but I think they would get better results if they increased their pulse width to 450 mA, and intensity as tolerated up to around 60-70 mA.  Also while I have not tried it yet, I suspect an ideal EMS program would not be just one set of parameters, but rather alternate between two or more, with some settings directed at increasing strength, and with others directed more towards improving circulation and cardiovascular benefits.  

Check out Chad’s blog to read more about Why We Use EMS Instead of TENS for Neuropathy.

 

Our Approach:

  1. Decrease pain
  2. To increase muscle mass to help with function
  3. Elicit strong muscle contractions
  4. Pump blood into the area in an attempt to improve circulation

 

1. Low Back Pain

I typically put four electrodes on the rectus abdominus (usually in a diagonal pattern), two electrodes more lateral to better target obliques and transversus abdominis, and just two on the lumbar region, which feels plenty sufficient at high intensity (as much as is tolerable rather than just what is comfortable). I also use a four channel machine so I can stim all the muscles at once rather than having to do the front first and later the back. I do a 10 second on and 50 second off period, 120 Hz , and 300 uS pulse width for 12 minutes. My combination of parameters closely approximates the “Russian Stim” duty cycle used on olympic athletes, also recommended by Charlie Francis as what he used with his sprinters. While perhaps coming across a white noise to patients with low back pain, a therapist understanding the specific EMS parameters is critical to getting an adequate treatment response. EMS performed this way is in fact exercising the muscles very intensely, and the parameters need to be adjusted as you would adjust exercise sets, reps and resistance level when weight training.

My patients report that this immediately decreases pain better than classic TENS patterns, that I used prior, and does more to increase abdominal strength than any conventional exercise I have ever tried; all while the spine is kept in a neutral posture with no external load. I think combining the treatment with exercise for extremity strength and spine awareness is certainly ideal, but I find the EMS to significantly boost both pain reduction and strengthening. The best part is that high quality machines are very affordable, so the treatment can be done at home while watching TV. As such, therapy time in the clinic can be maximized with whole body strength, endurance and spine awareness/motor control exercises.

Check out Chad’s blog to read more information about using EMS for Decreasing Back Pain, Increasing Core Strength, and Improving Endurance.

 

2. Neuropathy

While electric stimulation physical therapy patients usually report immediate relief after their EMS session, ongoing treatment seems to continually lessen symptoms. One patient case, with regards to increased sensation, has been doing the electric stimulation at home every other day for three months, and we plan to retest going forward. The use of a home stimulator is ideal because they often pay for themselves quickly and can make it possible to get the ideal use of at least three times per week, if not daily, that is recommended by research and fine-tuned by experience.

For neuropathy, I really want to try to not just decrease pain, but also increase muscle mass to help with function, to elicit strong muscle contractions, and to pump blood into the area in an attempt to improve circulation.  I think all of these things should help with neuropathic pain. For the lower extremities, I use four large electrodes (4” circular) and right now prefer to place two on the gastrocnemius, one on the tibialis anterior, and one on the sole of the foot. One thing I notice with my lower extremity neuropathy patients is they often need an especially strong stimulator to get a good muscle contraction; so while treatment is provided in the clinic, a lot of what Chad Reilly PT, MPT and his technicians do is help patients decide what kind of EMS/TENS machine and accessories they need, help them program the machine, and teach them how to set up the electrodes for home use.

Check out Chad’s blog to read more about Using EMS For Neuropathy.

External electric muscle stimulation has also been shown to improve pain, burning sensations, numbness, and sleep disturbances in patients with neuropathy.  In the study that revealed these findings, all of these improvements were based on patient reports, which is good, but as of yet nobody that I am aware of has objectively tested sensation to see if it changes. They noted improvement after the second treatment, and greater improvement after the eighth. Symptom reduction was consistent, but less than reported in prior studies. I would expect better improvements with daily or every other day stimulation (as the prior study seems to have had greater results with just 3 treatments on consecutive days), so I think portable but strong electric muscle stimulators patients can use at home would have led to a better outcome.  Also, treatment duration of 60 minutes does not seem to work any better than 30 minutes. Additionally, anecdotal evidence from my office is that just 12 minutes works pretty well, but I’m using a greater intensity of electric stimulation, with electrode pad placement directly over muscles in the painful/numb regions.

So my take home message from this study is daily stimulation is probably better than two times per week, and a really good study would be to objectively test sensation before and after a trail of EMS to see if lost sensation can be restored along with subjective reductions in pain and paresthesias.

Check out Chad’s blog to read more information about how EMS improves pain, burning sensations, numbness, and sleep disturbances in patients with neuropathy.

 

3. Headaches

The treatment of headache pain with the use of EMS is serendipitous, so I (Chad) will add some background information on how I came about it. As shown by some of my blogs posted in the “Headaches” category, in the last year I’ve been especially interested in electric muscle stimulation (EMS) to help recovery by accelerating strength gains better than exercise alone. A number of my knee and back pain patients commented that the EMS helped with pain reduction better than my earlier use of transcutaneous electrical nerve stimulation (TENS), which is basically the same thing as EMS but with shorter pulses and/or lesser intensity; with the intention of TENS typically being to control pain rather than restore muscle.

Around the same time I had a patient come in who had just suffered a stroke, and had severe neuralgia in one of her legs confining her to a wheelchair. She wasn’t able to tolerate any exercise with that leg because it was hypersensitive to pressure, so I figured I would try EMS on it and she would either like it or hate it. Turns out she loved it; it immediately and substantially decreased her pain, was walking later that hour, and had full recovery of leg strength, endurance, and gait in about a month. She asked me if it would work for headaches, so I said I would do some research and this is the first paper I came up with:

Peripheral nerve stimulation for the treatment of primary headache.  Curr Pain Headache Rep. 2013 Mar;17(3):319.

 

4. Tendinopathy

Electric stimulation physical therapy for muscles restores strength and activation in the muscles. In a 2006 study, the use of neuromuscular electric stimulation was used to improve activation deficits in a 62-year-old male patient with chronic quadriceps strength impairments following total knee arthroplasty. When beginning rehabilitation, his left quadriceps strength was 26% weaker than his right and central activation ratio (CAR) of his left quadriceps was 13% lower than his right quadriceps CAR. By the end of the treatment, authors stated: “The patient was able to achieve symmetrical quadriceps strength and complete muscle activation following six weeks of NMES and volitional strength training. An intense strengthening program may have the potential to reverse persistent strength-related impairments following TKA.”

Treatment consisted of reasonably aggressive unilateral leg strengthening with an emphasis on quadriceps for six weeks. On the weaker of his quadriceps they did electric muscle stimulation with two electrodes, 2500 Hz, sinusoidal alternating waveform current at a burst rate of 75 bursts with intensity to the patient’s maximum tolerance.

The researchers used only one channel/ two electrodes on the subjects quadriceps.   They used large electrodes making the electric stimulation more comfortable. However, in my experience they would have had even greater recovery if they had placed four electrodes on the quadricep to recruit a greater number of nerves and subsequent muscle fibers. The additional channel on the same quadriceps doubles the muscle fiber recruitment without the increase in discomfort you would get from further increases in current intensity. Also, if the EMS machine has additional channels you might as well put four electrodes on the hamstrings as well, or any other muscle that tests as relatively weak.  On most good EMS units those additional channels are there, so it seems a shame not to use them.

Check out Chad’s blog to read more about EMS for Strength Restoration.

 

5. Plantar Fasciitis

Unlike most other physical therapy clinics, I prefer to strengthen the intrinsic foot muscles with the use of Electric Muscle Stimulation, which gives the patient a superior intrinsic foot muscle contraction compared to muscle contractions accomplished through typical physical therapy foot strengthening exercises. For those with foot pain, physical therapists, and others treating foot injuries, is that foot intrinsic muscle strength needs to be restored, and I think EMS is the most efficient way to do so. This strength will lessen stress on the foot arch, and help promote optimal recovery from conditions like plantar fasciitis and posterior tibial tendinitis.  It should also go a long way towards preventing more debilitating conditions down the road, such as acquired flat foot deformity.

In my physical therapy clinic, by using the combination of EMS and strength exercises, I am noticing acceleration in the rate of recovery in my plantar fasciitis patients, most of whom have tried various foot stretches and orthotics for months with little or no relief. The 10-50-12 EMS parameters would be almost identical to what world renowned sprint coach Charlie Francis’ favorite duty cycle (10-50-10) used for foot injuries in his sprint coaching book.  I just like to add two extra minutes to my treatment to get the intensity of the machine where I want it.

Check out my blog to read more about EMS for Strengthening Muscles in Patients with Plantar Fasciitis

 

6. Fibromyalgia

A 2013 study tested the effects of a single treatment of TENS with people with fibromyalgia. It suggests that TENS has short-term efficacy in relieving symptoms of fibromyalgia while the stimulator is active. In practical terms it’s not exactly breaking news, as just about every fibromyalgia patient I see already owns one or more TENS machines.  Even so, this is still an interesting study because it showed immediate positive effects on central sensitization.

While TENS had positive effects in this study, in my physical therapy clinic I notice even greater reductions in pain and improvements in function with EMS parameters (electric stimulation parameters designed to increase muscle strength), rather than with TENS parameters.  The benefits of electric stimulation physical therapy over TENS parameters (even for pain) are great enough that I always search for research on EMS first for a given condition. Unfortunately, with fibromyalgia I have yet to find any studies, so you have to take what you can get. Anecdotally though, EMS works so much better that I almost never use TENS anymore.  The difference between them is only a few button pushes on the same machine anyway.

Check out Chad’s blog to read more about Improving Fibromyalgia with TENS/EMS.

 

7. Rheumatoid Arthritis

The outcomes from this multiple-patient case report indicate that Neuromuscular Electrical Stimulation is a viable treatment option to address muscle atrophy and weakness in patients with RA. Patients who completed the NMES and volitional exercise program increased their lean muscle mass, muscle strength, and physical function.

The case report that revealed these results described the use of NMES applied to the quadriceps femoris muscles in conjunction with an exercise program in patients with RA, and explored how changes in muscle mass relate to changes in quadriceps femoris muscle strength, measures of physical function, and patient adherence.

Seven patients with RA (median age=61 years, range=39-80 years) underwent 16 weeks of NMES and volitional exercises. This is an ideal situation for electric muscle stimulation: trying to maintain strength when active exercise might be too stressful, such as during an RA exacerbation. Improvements seem relatively similar to those shown with osteoarthritis and EMS. The EMS parameters used in this study can be found in the link listed below. I would use a longer pulse duration, higher Hz, shortened ramp, and set the on time to 10 seconds. That said, the parameters in this study sound reasonably decent. More electrodes on additional muscles would, I’m sure, lead to additional functional improvements, but the EMPI 300 model used in the study only has two channels. My preference is for four channel units like the EV-906 or Globus Genesy models, simply because you can work more muscles at once either at home or in physical therapy.

Check out Chad’s blog to read more about Using EMS to Help Rheumatoid Arthritis.

 

Case Reports of Past Success Stories

Low Back Pain

I had a patient with low back pain that had a near full recovery of strength, but had a persistent 1/10 pain which was reduced, but not eliminated, when using TENS. I mentioned he might want an electric stim machine for home; I had just started using it for core strength and thought it might help him build strength since his pain level plateaued. After using EMS for 12 minutes to his abdominal muscles and low back, he said he was pain free for the first time. Soon after, I read a study using EMS for low back that I recently blogged on that used similar pad placement and parameters for patients with low back pain. Since then, I have been successfully using that method as part of my treatment for my low back pain patients.

Neuropathy

EMS works exceptionally well for neuropathy/neuropathic pain, and I have seen it immediately eliminate arm tremors in a patient. This patient had gone through a bastion of tests at Barrow Neurological, been diagnosed with conversion disorder, then after a 12 minute EMS treatment the tremors were gone.

Neuropathy, Back Pain, Neck Pain

Another instance is when I was treating a 74 year old patient for poor balance, neuropathy, back pain, and neck pain all with a combination of exercise and EMS. She reported all of her other pain had resolved but she had elbow pain which I diagnosed as lateral epicondylitis/tennis elbow. I didn’t want to spend much time treating the elbow, as I thought it was the least of her worries. I wanted to continue to work on fall prevention with general strengthening, balance training, and agility training. The patient also had a history of dropping light objects, she calls it her “dropsies,” but over the course of her treatment she said it been reduced ~50%. Her muscle strength was much improved, so weakness was not a reason for her dropping objects. Long story short, I decided to add reverse wrist curls to her exercise program and did EMS to her biceps, triceps, and forearm muscles with a hope to further increase UE strength and lessen pain.  After one treatment, the following weekend she reported her dropsies had decreased another 30-40%, which is pretty big improvement over one intervention. The next day I applied EMS to her arm again, but also had her use my hand grip electrode to provide EMS through the palm of the hand.  So, on her next visit I will see what she has to say. Even though I treated the arm reluctantly, I maybe came up with a new understanding and breakthrough with her, which I can hopefully apply to other patients.

When you are using multiple interventions (which is generally the case in physical therapy) to treat a problem, it is sometimes impossible to say what does what and how much it does. Also, there is a lot of overlap between each intervention (strength exercise, balance exercise, coordination exercise, EMS) and what you are hoping to achieve. However, this patient’s rapid response was much faster than one would expect from a single day of exercise and I think it was most likely due to the EMS working on the muscles in the arm and hand and also increasing activation and blood flow in the brain. It’s also interesting that brain activity was seen in a dose response manner; in that more intense EMS causes more of a brain response. This perhaps strengthens neural connections and improves nerve conduction velocity, resulting in improved coordination. I am starting to see this in other studies as well. What’s also interesting is all the areas of the brain that are affected. Electric muscle stimulation applied to the study participants’ quadriceps increased blood flow to the primary sensory cortex, primary motor cortex, cingulate gyrus, thalamus, and cerebellum with blood flow always increasing more so in the brain as intensity levels of electrical stimulation was applied to the study subjects leg muscles.

 

Pad Sizes and Placements

I find you can comfortably get more current into a large muscle by adding electrodes, rather than just turning up the electrodes. Two electrodes (one channel) for large muscles like the quadriceps and hamstrings does not feel like it works the muscle as completely as four electrodes (two channels) on each; however, this depends on the size of the person, how many channels you have available, and how many muscles you want to work at once. Large electrodes are more comfortable than small ones because they lessen the current density going through your skin. Rubber carbon electrodes last a lot longer than sticky gel electrodes, but you do need straps to hold them in place. In my opinion stick on gel electrodes are more trouble than they are worth. Rubber carbon electrodes wet with water and held with good straps feel better, work better, and last a lot longer. I’ve tested all sizes and four-inch round rubber carbon electrodes are my favorite type, and size.  I’ve found that a four-inch wide elastic-velcro strap is best to hold them in place.

Click to view our suggestions of pad placements.

 

Obtaining Your Own EMS Machine

I do think home use of a stimulator is ideal, because they often pay for themselves quickly. I would expect ideal use to be at least three times per week, if not daily. Contact Absolute Physical Therapy to purchase your own EMS machine today! Supplies are limited.