Ask Mike Reinold Show

Restoring Muscle Function with Biofeedback

On this episode of the #AskMikeReinold show, I’m joined by Russ Paine to talk about the use of biofeedback in rehabilitation to restore volitional muscle contraction. To view more episodes, subscribe, and ask your questions, go to

#AskMikeReinold Episode 216: Restoring Muscle Function with Biofeedback

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Show Notes


Mike Reinold: Welcome back, everybody to the latest episode of the Ask Mike Reinold Show. I am here today, we’re going to flip the script again, and we’ve been doing this a bunch lately with obviously the COVID pandemic going on and us staying at home. Instead of us all being at Champion and answering your questions with my team there, what I’ve actually gotten to do is to team up with some of my friends and colleagues around the nation and ask them some questions. So instead of you guys listening to my garbage all the time and all my stupid answers, it’s time for me to ask some questions to some of the smart people that I know too.

Mike Reinold: So, today we have a very special guest, my good friend Russ Paine from Houston, Texas. Russ is the Director of Sports Medicine at UT Physicians Sports Medicine Group. I hope I said that well. You guys have probably heard me talk about Russ in a lot of my presentations because a lot of the things that I’ve learned and I’ve done on the scapula and, heck, lots of things on the knee and neuromuscular control rehabilitation, all these things I’ve learned from Russ and people all the time. But Russ, to me, is one of those groups of like godfathers in sports’ physical therapy that have been very influential to me. So if it wasn’t for the pandemic, I feel like we wouldn’t be doing these things, right Russ? But it’s great to have you on the show, so welcome.

Russ Paine: Thanks, Mike. Happy to be here.

Mike Reinold: Yeah, it was awesome. So a few years ago now… It’s been, what? How many years since the mTrigger came out?

Russ Paine: I think we hit the market two years ago.

Mike Reinold: Two years?

Russ Paine: We’ve been developing it for five years, so it’s been on the market for a year and a half, two years.

Mike Reinold: Nice. So, Russ has teamed up with another friend of ours, Brian Prior, that has done some good work with the light care laser and stuff like that. But they’ve teamed up together to come up with a new biofeedback unit called the mTrigger. And if you’ve followed me for some time, I’ve been talking about this now for years with Russ and been trying to help get the word out because what a lot of people don’t know is that people like Russ and I, and a lot of our friends, we use biofeedback a ton, even though it’s not readily available on the market. But we love biofeedback for postop patients, even some of our injured people that didn’t have surgery. But Russ, why don’t we start with that? Tell us a little bit about biofeedback. What happened to biofeedback and why did this fade away? Why is biofeedback not as common as it used to be?

Russ Paine: Well, I’d disagree with you a little bit that it never was a big thing.

Mike Reinold: Right, that’s a good point.

Russ Paine: It was over shadowed by muscle stim. So it didn’t come and fade away, it’s just been gradually building over a period of time. And I was one of the few people that used it. I use a little handheld biofeedback because I just didn’t feel like I was getting results with muscle stim, and I’ve had 13 knee surgeries. So I’ve tried all this stuff to get your quad back and all I put muscle stim on, I said, “Oh, that looks good, but I can’t make my own muscle.”

Mike Reinold: Right.

Russ Paine: So I started using biofeedback and I realized that my patients were getting better so much faster. I’ve seen all pro athletes and I see athletes that have had an ACL reconstruction in the NFL and they’re a year and a half postop and they come to me and they can’t do… They’ve got an extensor lag.

Mike Reinold: Crazy.

Russ Paine: They can’t even do a straight leg raise. And my patients don’t have that problem because we address that in the beginning. Part of the reason is that the devices were expensive too.

Mike Reinold: Right.

Russ Paine: They were two or $3,000 for a device and it really wasn’t that very user friendly. And the muscle stim market was so big. The reason the muscle stim market was so big, it was because it was a rental, reimbursable product and made millions and probably billions of dollars. So tons of money was issued to help support that as a rental product for research. There’s only a few articles on biofeedback because biofeedback got cut loose as a code. The actually code is still there, but most people, most insurance companies don’t reimburse because the psychology and psychiatric group abused that code for relaxation and that type of thing. So insurance company said, “We’re not paying for that.”

Mike Reinold: That’s crazy.

Russ Paine: So now we use the neural muscular code when we use biofeedback. So instead we do therapeutic exercise, manual therapy, and then neuromuscular code is what we use for biofeedback. So that makes senses, there’s really not a code for biofeedback that really works. Even though there is a code, most people don’t reimburse for it. But I think this is a… Since I’ve learned more about it, it’s a new wave concept that’s spreading through to understand the science behind why biofeedback works maybe even better than muscle stim.

Mike Reinold: Right.

Russ Paine: So when you have my device, which is very sophisticated, user friendly people can come in and download the app on their phone and get to work with it. They see the results and people that are really in tune with. Our patients love this device. And it’s up to your creativity, what you can do with it. So it’s all about starting to diminish the atrophy and inhibition that occurs day two postop. I’ll use the biofeedback for day two postop up to three months postop. Every time they come in, they get 10 minutes of quad setting. And our goal is to recruit more motor units.

Mike Reinold: Right.

Russ Paine: And that’s why my patients all do well. That’s one reason.

Mike Reinold: Right. And we all know that people, especially the complicated procedures, the big pain and the swelling in the knees and other joints, we all know that they have a terrible time with volitional control. So it’s funny, you hear other people struggling, or they say like, “Hey, contract that quad. “You’re like, “Yeah, no, I know I’m supposed to contract quad, I can’t. I haven’t been trained to do that well.” So we’ve been big fans of biofeedback just along the way, because I think it’s great that it works for volitional control, but a device like yours, like the mTrigger, it gives you feedback immediately of how much muscle contraction you’re performing. It’s biofeedback, that’s the whole point of it. It’s not just let’s turn on a neuromuscular stem and crank it up as high as we can, but let’s see how much you can press and you can contract.

Mike Reinold: And we know through all the research, that effort goes up when you have an immediate feedback and you see that and you know the outcomes comes back. So it’s great for volitional control. For me, I think a lot of the new grads and students in physical therapy just haven’t been exposed to it a little bit. So we know there’s neuromuscular stem. Why don’t you tell people that maybe haven’t worked with biofeedback much, what’s the difference on the inside between biofeedback and neuromuscular electrical stem, that NMES? What’s happening to the body differently on these two?

Russ Paine: Well, another point to make, just to finish it with one of your point was that patients like to grade themselves too.

Mike Reinold: That’s true.

Russ Paine: They come in and they’re like, “Oh my God, I can’t even make this leg go up hardly at all. I’m only at 300 microvolts.” And then they’d come in the next week, they’re at 1200 microvolts. So that’s another motivational thing.

Mike Reinold: Yeah.

Russ Paine: So the difference, I think, between the two devices is a scientific thing. And we’ve done a little… I did a little lecture that Mike’ll share with you that goes into detail on this, but it’s all about volitional contraction versus electrical muscle stim distally contracting.

Mike Reinold: Right.

Russ Paine: So when you have a volitional contraction, you use your brain. And we now know that there’s a decrease in cortical input in an ACL injured patient or anybody that has a swollen knee. So when you start with the cortex and go through the cortical pathways down to the femoral nerve, you’re involving the entire system. So that’s one thing that’s different. When you put electrodes on your muscle, it’s a distal brain. It’s on your quad. So that’s why you can’t put muscle stim on and wake up with a big muscle or big abs or whatever.

Mike Reinold: Right.

Russ Paine: And so the other thing it does is when you put electrical muscle stim on, this stimulates the largest diameter axons. Okay. So Mike, what is got the largest diameter axon the fast twitch or the slow twitch?

Mike Reinold: That’s type two. Right?

Russ Paine: Right.

Mike Reinold: That’s good…

Russ Paine: Good job.

Mike Reinold: That was pretty good. You got me nervous there, but type two.

Russ Paine: Type two. Okay. So what is the most inhibited muscle fiber type? Is type one or the slow twitch muscle fiber types are the ones that are inhibited the most. And that has been proven several times. So if you just stimulate the fast twitch and don’t get to the slow twitch, you never really start with this volitional order of recruitment. And when you make a volitional contraction, the first muscle fiber top that fires is the slow twitch. So an isometric contraction starts with slow twitch. And if you’re bench pressing or are doing a big squat, you bring in the fast twitch. And that’s a good thing to do because it develops muscle fiber size. But if you don’t start with the proper order of recruitment between slow twitch, to medium fast twitch, to high end fast twitch, then you never establish that hierarchy. And you never really reverse the inhibition.

Mike Reinold: Right.

Russ Paine: So over a period of time, patients start to get a volitional contraction. But have you ever tried to have a volitional contraction with the muscle stim? It’s hard.

Mike Reinold: Right.

Russ Paine: It’s hard to do. And that’s what we tell our people to do. I want you to work with the muscle stim, but they’re like, “Well, I think I’m doing it, but I’m not really sure.” But when you use biofeedback, you get immediate feedback and you start this order of recruitment to go from slow twitch, building up really strong contraction eventually to fast twitch. So that’s the science behind it in a nutshell.

Mike Reinold: Now, what do you do with somebody that is super acute? So they’re just days within surgery and they have zero volitional contraction. Do you ever use some NMES for a little bit to help them get over that hump? Or do you still go right into biofeedback?

Russ Paine: It’s not because I’m prejudice, its because it works. So I haven’t put a muscle stim on a patient in probably, I don’t know, maybe five years.

Mike Reinold: That’s awesome.

Russ Paine: So what I will do in that case is, we’re having them with their knee in full extension, the quadriceps in the shortened position, and they can’t make a muscle. It’s hard to do.

Mike Reinold: Right.

Russ Paine: If you’ve got a swollen, painful knee. Maybe they can do a leg rise. When you do a leg raise, the EMG goes way up. So I’ll shoot them over the edge of the table because they typically don’t have really any range of motion restrictions. In the video, you’ll see, in my presentation, we set a two day postop patients that couldn’t do a raise, couldn’t do a quad set over the edge of the table. And we had one of the top Texans quarterback that you know of that was having difficulty after his ACL. And I said, “Doctor Lowe, man, we’re having a difficulty ….” Sit him over the edge and have him do an active knee extension. So that’s what I do.

Mike Reinold: Yeah.

Russ Paine: Sit them over the edge, and if they can bend to 70 degrees or so, the peak EMG activity of your quad during an active knew extension is between 90 and 30 degrees on an active knee extension is out near full extension, but it’s at 30 degrees. So we do 90 to 40 and they can fire their muscle in that position.

Mike Reinold: That makes sense.

Russ Paine: Another trick you can do is have them in the gravity eliminated position. So just bring their knee up and full extension to a 90 degree position, just like we do with a rotator cuff repair, have them in gravity eliminated and try to hold their limb in that position and have them try to pick their heel up off your hand.

Mike Reinold: That’s great.

Russ Paine: That’s another tool. But the easiest thing to do is sit them over the edge of the table. You’re not going to blow the graft out.

Mike Reinold: No. They can’t even control the quad.

Russ Paine: With no resistance. And you’re not even getting their full extension. Now, if you had them do a 50 pound knee extension machine, maybe.

Mike Reinold: Yeah.

Russ Paine: But with this… That’s why people don’t do because you got so ingrained to orthopedic surgeons brain that knee extensions are bad for ACLs, but it’s not a problem in the acute stage.

Mike Reinold: Right. Yeah, no, I agree. So obvious implications for the knee. Especially ACL. We’re having patients that have quad strength deficits for months down the road. Who knows if we had just layered this on earlier to get volitional control earlier, would strengthen conditioning at the two, three, four, five month mark been much more effective? It’s mind blowing to think what we may have missed.

Russ Paine: It’s a variable that we have not looked at in the past.

Mike Reinold: Right.

Russ Paine: Now, there are EMG devices that were five to $8,000 where you could do a true EMG test, but there’s never been anything that is quick and dirty, that you can look at the neural muscular deficits. And that’s what we’re doing right now. And our goal is to compare our strength deficits that we see when we test them at six months postop in our followup program, and compare those strength test is to the EMG deficits.

Mike Reinold: Right.

Russ Paine: In my patient population, typically around two to three months we’ve gotten rid of the neuromuscular deficits.

Mike Reinold: That’s great.

Russ Paine: But as I said before, people jump the gun, they don’t restore strength and they jumped into functional movements and functional exercise and these swells, they had no e center control, they can’t decelerate and I’m putting them on the biofeedback and they’re fricking 50% deficit in their neural muscular control.

Mike Reinold: Right.

Russ Paine: That’s a variable that I think this is a wave of a mentality that I think people will adopt once they see it and once we publish things that this is one variable that we need to take off the shelf.

Mike Reinold: Right. And you know what it makes sense too, because if you look at how a quad functions, if you can barely do a quad set and a straight leg raise, and then you immediately jump into the gym and start doing some exercise, just because it’s week X, then you’ve missed the boat. But that’s the really neat thing about biofeedback in general though, is it’s not just an exercise tool, but you can quantify, you can quantify the contraction. You can compare side to side, you can look for a neuromuscular deficit. So this isn’t just a tool to rehab with, this is a tool to almost use as part of your evaluation process, too.

Russ Paine: Right. And we spent a little extra money to put in that neuromuscular deficit test because I thought it was important…

Mike Reinold: There you go.

Russ Paine: … To do a two channel biofeedback instead of one channel so we can do that comparison. So the other thing we’re doing in the next year is we’re partnering with a company called BlueJay, and they do home networking with patients, it’s HIPAA compliant. So eventually the patient will be able to download the app on their phone and they’ll have a folder of their EMG data that we can share, and we can pull it up and look at it together. The physician can see that. And this is one thing that if you guys have a mTrigger out there that are listening to this, I’ll put these numbers down in my notes objectively.

Mike Reinold: Right. Sure.

Russ Paine: So instead of saying, “Quads a little bit better, better muscle tone.” I’ll put, “They started at 700 microvolts, now they’re are 1200 microvolts EMG.” So this is an objective criteria that allows us to document a patient’s progress. And the patients love it. They like to see the numbers that they’re getting better.

Mike Reinold: Yeah, no, that’s really neat. And we’ve talked a lot about using it on a muscle group to get a muscle groups volitional control back and to get it stronger down the road. Another neat thing that I do with biofeedback, I wanted to throw at you and then see if you have any other creative things. But the fact that it’s two channel, I like to do certain exercises with two different muscle groups on two different channels. So making it up off the top of my head, but maybe say a hip extension and we have some of the pads on the low back and some of the glutes. And I say like, “Look, I want you to do this bird dog for a hip extension. I want to see glutes and less back.” I want to make sure that we’re doing it right. Or the right core is firing or heck even upper trap, the lower trap ratios. What other neat ways do you use it? Because I’m sure you’re even more creative than I am.

Russ Paine: Well that’s for sure.

Mike Reinold: Good answer. That was good.

Russ Paine: No, you’re Mr. Creativity. So I’ll learn a lot from you. One thing that’s really helpful is to use it with prone planks, for teaching people to do a lumbar stabilization program. So you want to fire your abdominals and your erector spinae together to brace with that.

Mike Reinold: Right.

Russ Paine: And so you teach people neutral spine positioning, you teach them to brace, but they don’t really know whether they’re firing or not. But with the mTrigger you use two channels, you can see exactly what’s going on and you say, “Well, you’re not really firing your abs.” “Well, I think I am.” But I said, “You need to get that… Oh your erector spinae is going down.” So you can use it for that. That’s a really good, I don’t see that many spine patients, I see a few, but the spine therapists are crazy with it.

Russ Paine: Now strength and conditioning is a whole nother ball game. And it’s a really good tool for performance individuals that are strength coaches and also personal trainers. It’s a great tool for them. With regard to the shoulder, posterior cuff and the lower trap are two great sister muscles that work together with different activities. I’ve got a bunch of videos that I think you’ve seen so that we can fire the posterior cuff and at the same time, try to get a posterior sculpting of the scapula. Now Phil Page has used it for limiting upper trap activity along with lower trap, so some people believe that the upper trap maybe like an antagonist of what you’re trying to achieve. So you can use one channel for inhibition, the other channel for contraction.

Russ Paine: Now, another thing we’ve been doing reasonably well, if you have bilateral knee patient, you can use two channels. And the patient can do both of those knees simultaneously during the rest period of one, do the other one. You know me, I’m brutal. The other thing you can do is you can do quadriceps and hamstring contractions, but I don’t do a co contraction. I do 15, 10 seconds of quad, and when the quad relaxes, do a hamstring isometric. We never do hamstring isometrics.

Mike Reinold: Right.

Russ Paine: But hamstrings are a really important muscle group, we forget about that. But it’s really up to your creativity. That’s the beauty of this device is you can think of things to do. And the other fun thing to do is put it on the serratus anterior and try to prove some of these research articles that you’ve seen that this climbing of the wall with your elbows against the wall, what do you call that? I can’t remember. Does that increase your serratus activity? And sure enough, it does.

Mike Reinold: Right.

Russ Paine: What about the dynamic …? Which one’s a better exercise? What about rowing or what about manual resisted external rotation? So you can prove it to yourself. So it’s a fun tool.

Mike Reinold: Right. And everybody’s different. When we look at those studies and we look at a mean of a group of subjects. You may find that one exercise is better than another for a certain person. So the more individualized the better. So awesome. So this is my favorite episode right here, because one, I don’t have to talk the whole time, it’s fantastic to actually ask smarter people questions. But Russ is the man on biofeedback. And this mTrigger device is really amazing and ridiculously affordable. There’s no reason why everybody shouldn’t be using this. I just think people don’t know about it. So hopefully we can get some awareness to this because it’s something that some of the best sports physical therapist I know are using. So the best are using it, I think it’s something everybody should use it.

Mike Reinold: So we learned about the science behind it. We learned about why it’s better than neural muscular stim and some creative ways to use it for a bunch of different things. Thank you, Russ. I appreciate you taking the time out of your schedule and the freaking pandemic that we’re having to do that. So thank you very much.

Russ Paine: Thanks, Mike.

Mike Reinold: Yeah.

Russ Paine: Thanks for having me.

Mike Reinold: Awesome. Yeah. And if you have any more questions like this, even though I asked all the questions, but if you have questions too, you know what to do, go to, click on that podcast link, and you can fill out the form to ask us questions. Be sure to rate and review this on iTunes and Spotify. And we will see you on the next episode. Thanks so much.