Quadriceps shutdown after ACL reconstruction is one of the biggest barriers we see in the clinic. Even with modern surgical techniques and “aggressive” rehab, too many athletes struggle to get their quad strength back, and that deficit shows up later in gait, loading, and confidence on the field.
A new systematic review and meta-analysis just took a fresh look at neuromuscular electrical stimulation (NMES) as an adjunct to ACL rehab. Does adding NMES actually move the needle on quad strength? Does timing matter? And does any of this translate into better knee function where it counts?
In this week’s podcast, we break down what the authors found, how strong the evidence really is, and how we’re thinking about NMES programming in our own ACL protocols. If you’re working with post-op knees, you’ll want to hear this before you set up your next rehab plan.
To view more episodes, subscribe, and ask your questions, go to mikereinold.com/askmikereinold.
#AskMikeReinold Episode 379: Should Every ACL Get E-Stim? What the New NMES Meta-Analysis Really Shows
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Show Notes
• Evaluation and Treatment of the Knee online course
• Effects of Neuromuscular Electrical Stimulation on Quadriceps Femoris Muscle Strength and Knee Joint Function in Patients After ACL Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials
Transcript
Mike Reinold:
Welcome back, everybody, to the latest episode of The Ask Mike Reinold Show. We are here at Champion PT and Performance up in Boston. We have another journal article review today. We have Anthony Videtto, Diwesh Poudyal, Lenny Macrina, Dave Tilley, Mike Scaduto, and Dan Pope here to review an article being presented by Brendan Gates. And the article is The Effects of Neuromuscular E-Stim on Quad Strength and Knee Function After ACL Surgery, a systematic and meta-analysis. So, cool study out of a group of researchers from China published in OJSM in 2025. Gates, take it away. What did this paper show? And I’d love to hear how this could change our practice.
Brendan Gates:
Yeah, absolutely. Thanks for taking the title out of my hands there. It’s a long one. Appreciate it.
Mike Reinold:
I summarized it too. That was the abbreviated version.
Brendan Gates:
That was good. So, as you had mentioned, this was written by Lee et al in the Orthopedic Journal of Sports Medicine. It was published this year, in 2025. The purpose of this paper was to determine if adding neuromuscular electrical stimulation, or NMES, as an adjunct to standard rehab, improved quadriceps strength and knee function compared to just standard rehab alone. So as Mike said, you can tell from the title, this was a systematic review and meta-analysis of randomized control trials. Essentially, they included RCTs that looked at patients who had undergone ACL surgery, so reconstruction or repair, in clients that were 13 years or older. To be included, these RCTs had to have two groups. An intervention group, which had patients who were using NMES as an adjunct to standard physical therapy, which was their primary intervention. And then a control group, which had clients who were treated with just standard physical therapy alone without any sort of NMES.
Through the 11 studies that were included, there were a combined 202 patients in that intervention group using NMES and normal PT, and then 200 patients in the control group with just PT alone. They pulled data on short-term, less than six weeks, and long-term, greater than six weeks, follow-ups, and they objectively assessed quad strength through isometric or isokinetic testing, and then knee joint function through lysosome scoring, which is patient report outcome measure. And the results were that they found that the NMES plus standard rehab group significantly increased quadriceps strength compared to the PT alone group at both short-term and long-term follow-ups. This study even offered a couple of explanations for why this could be the case, and so they offered two. One was they said that the quadriceps strength gains could likely be attributed to NMES effectively reducing the atrophy of skeletal muscle fibroblasts. And then number two, they said that NMES has a postoperative analgesic effect that promotes the early initiation of functional exercise in patients.
When they looked at the lysosome scores for knee function, they did not find a significant improvement in lower limb function in the NMES group there, but they did find that this quadriceps strength improved in the patients that used NMES as an adjunct to standard PT. As far as clinical implications goes, I think that this article kind of confirms what I think a lot of us practice here at Champion anyway. I think we’re pretty big fans of that Chattanooga NMES machine with the trigger. And so early on, using whatever we can to combat quad weakness, which we know is kind of a lasting issue, as I’m sure the listeners have heard Lenny say a million times on here. If we can use it to help them get a little bit stronger a little bit earlier, and through a rehab, I think it’s a no-brainer to use in our rehab there.
So I think it’s important to note those two things that they said in terms of NMES, is why it’s helpful. So, reducing the atrophy of skeletal muscle fibroblasts… If we can attenuate any sort of atrophy, whether that’s disuse atrophy or postoperative atrophy, I think that’s super helpful. The sooner we can do our quad sets and our straight leg raises and move forward to some weight-bearing activities with good strength, the person’s likely going to have a better outcome. And then the analgesic effect I think was interesting. I’d be interested to hear Dan’s thoughts on this, but I know that Delaware ACL protocol talks about the MVIC that you’re supposed to do in terms of dosing NMES, and I think it’s pretty high. And in research, it might be a little bit different than what we can actually get people to clinically. So essentially, pumping it up as much as they can tolerate, maybe it distracts them from some of the pain of surgery, allows them to get the quad firing a little bit more. And then, like we said before, it gets them to do just more exercises a little bit sooner.
So I’m a big fan. I use NMES quite a bit. I’ll start with some heel pops and the quad sets early on, try to use it with straight leg raises into TKEs. And then even further as an accessory for quad strength, so knee extensions, even pair it with some BFR once they get a little bit further out. So I certainly use it. I think this was cool to see. Interested to hear your guys’ thoughts.
Mike Reinold:
Awesome. Thanks, Brendan. Great summary of everything. I like articles like this. Again, I’ll put this on social media every now and then, but sometimes we love to fight about what not to do. So it’s actually cool to go through an article that talks about what to do, sometimes. I think that’s refreshing. But Dave, what do you got? What were your thoughts on the study? I’d like to hear what you guys think.
Dave Tilley:
I agree. I think it was super helpful to find a good systematic review of stuff that we’re doing that works well. I think for me, and the other study that we’ll talk about in the other episode, I feel this way too. Sometimes when you look at the methods of a bunch of different studies, you want to see exactly what they’re doing in the trenches because, as we know, quote unquote, “Standard physical therapy” is massively different across facilities. So we’re very fortunate, where we have an hour… I can think of some patients where I just happen to have a gap in my schedule after, and our session is an hour and a half long… From the moment they walk in the door, all the way through all the range of motion, all the exercise, all the stuff we’re doing. So I think that sometimes the standard of care in maybe a place that’s a little busier, or doesn’t have access to a lot of space, time, equipment, waits, what they’re doing for sets and reps, especially in the mid to later four, six, eight weeks.
I can think of some times when we’re in the gym for a lot of the program when we’re six weeks out, and we’re modifying things based on their graph choice. But I think standard of care, sometimes I want to know exactly, summarizing a table for me, how many sets, how many reps, were you using, weight, was it closed chain, open chain? Did you have a trigger? Were you doing a timed on 20, 10 kind of situation? Because not everyone has the Chattanooga trigger. So I think in a study that’s interventional, looking at a lot of other places, I want to really have a good table to summarize exactly what exercises, sets, reps, frequency, dosage, because as a clinician, I want to do… If 11 studies say that this combination of exercises is what they use and everyone’s using those things with progressive load, I want to definitely make sure that I’m following that, not just doing body weight, leg raises, or short arc quads.
Mike Reinold:
Yeah. Dan?
Dan Pope:
Yeah. We talked about this relatively recently, like six months ago, because I did look through some of these studies. And I didn’t look through all of the studies mentioned. I think what Dave had mentioned is very important. We have to figure out what the methods are. And I thought that was a really interesting point about the standardized physical therapy. What the heck does that mean? But the other piece is that, how do they use the NMES? And then in a lot of these studies that they’re referencing here, they utilized NMES, and they had the patient do it daily, and they weren’t doing it with exercise always. And some of the studies they just basically had the stim on, and they’re doing, to your point, they’re trying to crank it up, usually as tolerable as they can. For the study at Delaware, I think they’re at 50% MVIC, like post-op date two or three after ACL at 90 degrees.
So that’s extremely high. I don’t know that I’ve ever been able to get a patient that high in terms of how much they can tolerate, but I think that what was nice, reading through some of these studies, is that you don’t have to get that high to get an effect. It’s usually what’s most tolerable. Extra brownie points if you can get that muscle contract. And the other piece is that patients will kind of habituate to it throughout the session, and also from session to session. So get more comfortable over the course of time, it’s less scary and improves. But one of my thoughts, too, is that we probably should be ordering maybe like a NEHAB unit or something along those lines. They use the NEHAB in some of these studies, but these folks were doing this for up to an hour almost daily in a lot of these studies.
And that’s just not what we do at physical therapy. In physical therapy, we’re trying to do so many different things. We’re doing exercise, we’re maybe icing it beforehand, we’re doing blood flow restriction training. We’ve got so many things we could potentially do with these patients that it’s probably worthwhile to see if we can get them a unit, see if their insurance company will cover it, and have them just do it at home. Because, like I said, when we’re in the clinic, we’re doing stim with a trigger. We’re exercising with them. In the majority of these studies, that’s not what they’re doing. They’re basically putting those pads on and having them just hang out or work isometrically. So at least one of my takeaways, when kind of looking through the studies, is we should probably start ordering these for patients right away because it really does seem to have a longer-term outcome, which is really nice.
And we can’t really follow the methodology of the studies in the clinic.
Mike Reinold:
I feel like if we all tore our ACLs, we would all be having an NMES unit at home.
Dan Pope:
Yeah.
Mike Reinold:
You would be probably doing it multiple times a day if it was any of us. So man, they’re not expensive on Amazon. You can get an NMES. We’re peculiar. We like the trigger ones. I think Brendan mentioned the Chattanooga one because it has the trigger. But I actually think from this study, you could argue there’s two ways of doing it. It’s the super high intense, just sit there isometric contraction. And then it’s using it superimposed on exercise. And I think both have validity, and putting them together I think would be very helpful. Especially, to Dan’s point, sometimes it’s hard to get people super high, 50% MVIC. Although I’ve talked to Delaware, I talked to Ariel Giordano about this, and she’s like, “Nope, they do it on all their patients. Immediately post-op. They just do it.”
And I was like, “Well, that’s why my patients like me better than yours.” But to me, I think it just comes down to, though, if you have a nice, strong, visible tetany. And I think this study actually helps us with that. I thought that was pretty good. But what else? Anybody else have anything that they got from this? Anthony, what do you think?
Anthony Videtto:
I just wanted to point out that the other outcome, or at least what I read, was that patients who started less than a week post-op had better outcomes in terms of strength and functional outcomes too. Which just goes to show that getting into PT earlier is so much more beneficial than waiting seven, eight, 10 days, whatever the case may be. Not only for starting some rehab stuff with the PT, but then, we educate patients, like Dan said, on maybe getting an at-home unit. So they’re doing stim in the first week because that shows that yes, functional outcomes, strength outcomes are so much better if we start in that first week than if we were to wait however many days after post-op.
Mike Reinold:
That’s a great one, Anthony. The results actually are pretty high. I think that’s one thing you should take from this article, is that we need to start NMES in the first week if you haven’t yet. Some people are like, “Oh, they’re too sore,” whatever, we’re dealing with range of motion or something like that. I think the effect that we saw in this study is so large that it would be naive not to. So, awesome. Good stuff. Lots of good stuff for this. It’s good to see some evidence. And I think what we can do is we can refine what we do. Think about it. NMES to us, I think, based on this article, I wrote some things down… It’s not optional. It’s something we do on everybody. We want to start super early, like that first postoperative week. We want to use it on everybody as much as we can with high visible tetany. I think that’s important.
And just remember, it’s part of a bigger system. Don’t lose the fact of that. You’re not just doing this, you’re still doing all the other things, but if you can superimpose this on top of exercises, especially early on, the outcomes speak for themselves. So great study. Appreciate it. Thanks for the nice review, Brendan. That was awesome. If you’re liking these episodes, please let us know. We’ve gotten some good feedback on some emails and some posts on social media, and YouTube, and stuff like that. So please, thank you for sending those. We’re going to keep doing these reviews because we think they’re nice. I think we like them too, to be honest with you. Hear how everybody said they did homework to prepare for these? It’s pretty cool.
But anyway, thanks a lot, and we’ll see you on the next episode.
