Should we perform open kinetic chain exercises after ACL reconstruction? Current research suggests we should. However, make sure you understand the science.
Here’s how we use OKC knee extension at Champion.
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#AskMikeReinold Episode 264: Open Kinetic Chain Knee Extension After ACL Reconstruction
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Show Notes
Transcript
Student:
So Dave from Instagram asks, “I always enjoy your online content and appreciate your approach to PT. I was wondering if I could ask you a question that has come up with my staff? Do you incorporate open chain knee extension exercises with your ACL patients and when do you start? When do you start to load an open chain knee extension exercise, any parameters you incorporate?”
Mike Reinold:
Awesome, good stuff, Zack. So Dave, great question. I was really excited about this question, because I think Dave nailed it. So I think what’s happening, just like everything else, there’s a lot of buzz online about this and I think as we get to a culture of social media where everybody just likes to debate things all the time, I think we always just hear bits and pieces of this. But I think what’s really happening now is we had two great pieces to the literature in last not even 12 months.
Mike Reinold:
There is a commentary from Lynn Snyder-Mackler in JOSPT, the end of last year, that talked about using open kinetic chain knee extension after ACL reconstruction and saying that we need to do it. And her big thing was it’s safe, it’s effective, and it’s something that we must do in order to get strength back. I think what it was missing though, like Dave kind of says there, is any guidelines. And I think a lot of people could take that the wrong way, right? Like where you can just say, “Wow, Lynn Snyder-Mackler, she’s prolific with ACL research. She’s so smart, she’s so great. She’s saying we need to crazy, we need to go heavy open kinetic chain knee extension.” It was too broad.
Mike Reinold:
So Kevin Wilk just recently, in the International Journal of Sports Physical Therapy, just kind of published another one. It said he kind of agrees with Lynn, but that we have to be careful. We just can’t blindly go blasting away with open kinetic knee extensions. But again, I don’t think Kevin’s paper had parameters either. So let’s talk about that. Who wants to start this one off about … Obviously the question is, do we do open kinetic chain knee extension exercises and then let’s try to establish in this episode maybe the parameters that use at Champion, which are very research based, but who wants to start off?
Dave Tilley:
I mean, I will because I tend to get into the heat of battle on social media with these, and I think people really take a black and white approach to these. They either, “I don’t do it because the doctor says I can’t or I’m taught that I shouldn’t because school.” I definitely have evolved the past, I don’t know, five, 10 years in my thoughts because I tried to dive into the literature and see if there’s anything, anything obvious in anterior tibial translation which is always the argument that you’re putting extra stress on the ACL by going that 30 to zero range of motion. I am struggling to find something concrete to really pull me back. That doesn’t mean I’m being aggressive and doing 50 pound knee extensions two weeks after surgery.
Dave Tilley:
So, in my head, I tend to get a couple weeks out of surgery and let things heal down, especially that anterior knee. I’ll do some, maybe, isometrics. I talked to Eric [Meira 00:06:01] about this. We talked about this lot, doing some isometrics to let the anterior knee kind of get accustomed to a stress on it. And then I like to do some just open chain knee extensions, meaning sit at the edge of the table, if they have the range of motion … Usually at two weeks out, they have 90 degrees. So that’s when I feel comfortable doing it. I’m certainly not going to force it if they’re still struggling range of motion. So range of motion is a checkbox too, right? Swelling’s coming down, range of motion, pain is down. I’ll initiate it maybe with active motion, maybe light ankle weight, and then I’ll progress from there.
Dave Tilley:
But, if I remember from Kevin’s article and just talking from people in general, you got to watch the graft too, right? The patellar versus a hamstring graft is going to be very different in how I treat them. Hamstring grafts, I go a little bit less aggressively because it’s a soft-tissue graft and is not a bone interface attaching to the femur or the tibia. So I don’t want to stretch out the hamstring by putting a little extra stress through it. A patellar tendon and a quad tendon, I’ll probably be a little bit more aggressive than a hamstring. And for a cadaver, which I very rarely see, I don’t even … I tend to just kind of shy away for a while and maybe even wait six weeks, because I just don’t trust cadavers in general. Maybe even wait 12 weeks. I don’t know if that is …
Mike Reinold:
Yeah, and even you just bringing up the different grafts I think is something that’s missing. If you just take Lynn’s paper just in and of itself, it’s like, “Do a lot of open knee extensions, and do it heavy, and do it with everybody.” Right? And it was almost like that we’re crazy if we’re not doing that. And then Kevin was almost trying to give a little bit more parameters that as you start getting to terminal knee extension you put tremendous amount of strain on the patellofemoral joint, on … If you just had patellar tendon graft, right? Or even any strain of the ACL, it comes down to, does it matter type of thing? I think it’s very clear.
Mike Reinold:
One quick question have for Diwesh, and we don’t have to get into this a little bit here, but Dewey … Oh, I forgot to introduce everybody, by the way. I just totally remembered that. But anyway, Dewey, how many people in our gym do open kinetic chain knee extension for quad strengthening?
Diwesh Poudyal:
None, because we don’t have a viable [inaudible 00:08:11]. I get the question though, right? I think is it a necessary exercise, at least from the performance realm? Probably not. Is it a potential exercise that we can use, where you kind of target a little bit more like quad hypertrophy and isolate quads a little bit more? Sure, yeah, great option.
Mike Reinold:
Right, right. I agree. That is a great option too, but there is so many ways to get quad strengthening, that I think that’s a big part of it, that we all do it. So let’s try to set some parameters, right? Let’s get everybody. We’ll have a Champion consensus statement. Poof. Let’s get this published, right? Consensus statement here. So first consensus here. Do we all use open kinetic chain knee extension after ACL reconstruction? All in favor?
Lenny Macrina:
Yes, yes.
Mike Reinold:
So we all agree you can use open kinetic chain knee extension. When should you start? Lenny, would you like to propose two weeks once they have 90 degrees of knee flexion?
Lenny Macrina:
Yes. I think good range of motion, minimal pain, incisions healing. Again, graft choice is going to play into my … At least in my head, I’m a big patella tendon guy. So I see a lot of hamstrings because that’s what they do in Boston. But I think two weeks probably at the earliest just to let things kind of calm down and not stress that anterior knee. And like you mentioned, the [inaudible 00:09:38] joint stresses.
Mike Reinold:
All right, so we’ll say we start somewhere, two, three, maybe even four weeks if we’re trying to go a little slower on somebody else, right? But we’ll say we start two weeks. All in favor?
Lenny Macrina:
Yep.
Mike Reinold:
Right. I was right. So we start at [2-E 00:09:54]. Should we start at 90 to 40? Should we stop at 40? I’m going to start and say yes. Does anybody want to say we should immediately start going to zero?
Lenny Macrina:
I would say we can start it there and just see how the knee responds, and especially if you’re going to do it earlier, and you want to test things out, yes. If you want to buy time, that earlier time, and do it, I’d say yes.
Mike Reinold:
So you get some benefit of open kinetic chain knee extension, but we’re minimizing strain right as the graft is starting to become vulnerable, or really more vulnerable probably.
Lenny Macrina:
And that last 30 degrees of open chain, that 30 to zero, 40 to zero, is again, when the most stress is on the patellofemoral joint.
Mike Reinold:
Right. So more stress on the ACL, more stress on the patellofemoral joint. Probably more stress on the tendon, too, as we get to that point. So lots of things. So we’ll 90/40. Do we start loading open kinetic chain knee extension, right? We definitely want to load it, right? So we do a progressive resistance thing. When do you start going all the way to zero?
Dan Pope:
Six to eight weeks probably.
Mike Reinold:
Oh, on average, right? But what if somebody’s at four weeks and they have full range of motion, no pain. They can do it easily, lock out that knee. Would you start it with no weight?
Dave Tilley:
Yeah, probably no weight [crosstalk 00:11:13].
Lenny Macrina:
I do.
Mike Reinold:
So you want to start it with no weight. So maybe you’re doing 90/40 with the resistance, but then you’re doing it all the way up to zero with no weight?
Dave Tilley:
Because this person probably also doing, if they can weight bear, they’re probably doing zero to 45 close chain. So they’ve experienced-
Mike Reinold:
Definitely, right. Definitely. Yeah, no, I totally agree that they’re going to quad strengthening and they’re going to get terminal knee extension in other ways too, right? So it sounds like we start 90/40, we’ll start loading 90/40, and then we’ll open up the window to zero with no load initially, and then slowly load it, right?
Dave Tilley:
Right.
Mike Reinold:
Does anybody think we should be doing max effort open kinetic chain knee extension? All the way fully straight like on a machine, for example, like we don’t even have at Champion? Is that … Do you know what I mean, like that is good, but I think that was one of the things big things in Kevin’s article. He suggested that we should avoid that for six to nine months. So early, aggressive … That’s aggressive though, Len, I see your face. Open kinetic chain knee extension all the way to zero.
Lenny Macrina:
Yeah, yeah.
Mike Reinold:
Like on a machine, like as heavy as you can. And, to me, I think that was the direct statement that Lynn’s article didn’t have there. I think what he’s saying is like, “Yeah, go crazy, load it 90 to 40, load it up to zero, but don’t load it aggressively for six to nine months all the way up to zero.”
Lenny Macrina:
The only thing I don’t agree with that, I guess is a lot, is I know in Birmingham, and in other places, in an outpatient facility … We don’t have it, but a Biodex is three months out of surgery to test quad and hamstring strength. That’s a max effort open chain full range of motion.
Mike Reinold:
But I think there is a difference between doing it once versus doing daily or three times a week.
Lenny Macrina:
Maybe. I mean …
Mike Reinold:
I know what you’re saying though.
Lenny Macrina:
I just don’t know why at six to nine months we can’t do it. Like where in the literature is this? What is the study?
Mike Reinold:
I mean, you’re never ever, ever, ever going to have a study that tells you the answer.
Lenny Macrina:
Probably not. I just don’t know where it initially came from? What’s the thought? What? The anterior tibial translation and where is that’s from? I’m missing it. There is something out there, like from the ’80s or early ’90s.
Mike Reinold:
This is what Kevin put in his paper, but you have unopposed anterior tibial strain because the hamstrings are not involved in open kinetic chain knee extensions. So you have unopposed anterior strain, you have dramatic in crease in patellofemoral stress as you get going there. It’s a lot harder in there at that terminal knee range of motion. I think those are his two big things. He’s not saying don’t do open kinetic chain knee extension with weight, he’s saying don’t try to max out on it for six to nine months. I kind like his point, right?
Mike Reinold:
I like these two papers together, right? Because I think Lynn’s trying to say we shouldn’t be afraid of this, and I completely agree with that. I think she did a great job with her paper. And I like how Kevin’s saying you can’t say … I think what’s Kevin trying to say is you can’t say that to students and early career professionals because they’re going to go bananas. They’re going to take that too far and he’s trying to say, “Whoa, there are some parameters in it.”
Mike Reinold:
So I guess that’s the only thing. Anybody else want to jump in on max effort loading with open kinetic chain knee extension, when do we get to that? Dan?
Dan Pope:
I was just going to say, whoever does a three rep max knee extension? When does that ever, ever happen?
Mike Reinold:
That’s a good point. That’s a good point.
Dan Pope:
It seems kind of ridiculous to me. So I think it’s kind of challenging to say, “Heavy, heavy, heavy.” What the heck does that mean? If I’m doing sets of 10, am I ever loading heavy enough, even if I am going to failure? I guess, like you said, I don’t think we’ll ever know, but I just don’t know when in a training program you’d be doing under, let’s say, five repetitions in knee extension. Just don’t think that’s where I’d want to get the majority of my strength from.
Mike Reinold:
That’s actually a very solid point. But again, this isn’t a knock towards Lynn’s paper, but there’s no guidance with that. She was just saying we need to do it and we need to do it heavy. You know what I mean? So Dan, you think that’s commonsense, I think a lot of us think that’s commonsense. But I just wonder if not everybody has the experience you have with that, that you realize how you would do that. And I think that was Kevin’s kind of point was kind go easy.
Dan Pope:
Yeah, patience.
Mike Reinold:
Yeah. I mean, I don’t know the answer too, but I like what we do. I think we do moderate strength training all the way to zero with our open kinetic chain knee extension, but the majority of the strength we’re getting is probably not knee extension, right? Again, we don’t even have a machine at Champion, so I mean, we’re doing it with ankle weights. So that tells you, I mean, I think we have good outcomes, right? So I don’t know. All right, I still feel like we need to nail that’s though. So what do you want to propose, Lenny, on how heavy you can go on knee extension and when are you fully cleared to do whatever you want?
Lenny Macrina:
I think what Dan said was going to be my next one, was just can they do eight to 10 reps and get a good burn? And at the end of that 10th rep, are they feeling a good burn in their muscle that they can’t do an 11th rep or 12th rep? That’s, to me, a good parameter of two, three sets of that somewhere in their program. But they’re also squatting and deadlifting and lunging and everything else. People don’t think we’re just talking about open chain stuff. That’s built into the program to isolate the quads, but then we also get the quads in other exercises. Just want to make sure people understand that.
Mike Reinold:
Right. And this is an excellent, again, excellent use of something like blood flow restriction where we can do an exercise with less load because we’re trying to protect stuff. I think Lynn’s paper was excellent because it’s trying to tell people we can’t be afraid of open kinetic chain. It’s not unsafe, it’s not less functional, right, because quad strength’s functional. So she made great points. I think Kevin’s paper actually had excellent points too, where it was like, “Yes, but you have to be smart with how you’re prescribing that.”
Mike Reinold:
Let me try to summarize. So yes on open kinetic knee extension. We usually start about week two just to let the knee heal down, let the incision heal a little bit, make sure they can get some … about 90 degrees of knee flexion, that makes sense. We’ll start 90 to 40 for a little bit, maybe like a couple weeks or so just to kind of get things going. But then we’ll open it up to zero. We’ll start loading 90 to 40, right, and kind of keep the load 90 to 40 initially, but then slowly start opening up that window.
Mike Reinold:
So I’d say probably, what, week 12 maybe? Three months out or so, they’re probably doing whatever you can do with ankle weight type things with open kinetic chain knee extension all the way up to zero pretty easily. Probably from month three to maybe month six to kind of use Kevin’s things, we slowly increase the load on that if you want. But we’re probably avoiding max until we have full graft healing and everything, right? Like a max effort open kinetic chain knee extension which I think Dan’s point is we don’t need that anyway, right?
Mike Reinold:
And Diwesh said we don’t need that, so to Lynn’s point, yes, we need open kinetic chain knee extension, but there’s other things we can more safely do with aggressive weight, right? Like where you have co-contraction of the hamstrings, you’re doing it in a closed chain fashion where it’s a little bit more safe. I don’t know, what do we think? Is that good? Anybody, did we miss anything?
Diwesh Poudyal:
The only thing I was going to leave off with was, at least from the performance end of things, right, when we start thinking about … Because the point about max effort was the one I was really stuck on, and I 100% agree with Dan, we wouldn’t load up a max effort bicep curl or a tricep extension for a set of three, right? We don’t have strength-testing parameters for 3RM bicep curl or tricep extensions. But it’s just like the commonplace to load max effort with the right exercise choice. You could probably take your ACL patients and take them to sets of three, sets of five on squats, really test force pressure for the lower body right? Because eventually they’ve got to get back to sport and all that stuff, but yeah, like a super heavy max effort knee extension just doesn’t make a whole lot of sense to me.
Mike Reinold:
Yeah, love it. Yeah.
Dan Pope:
Like risk reward, what kind of information are you getting with a three rep max versus like a eight to 10 rep max? Is it really worth it to do that?
Mike Reinold:
Right. Yeah, so again, I think you guys … It’s the same thing. I think that was maybe Kevin’s point with Lynn’s … I haven’t talked to Kevin about this, by the way, but just assuming from reading it. I think that was his point, was that we have to be careful. I, personally, as an educator, right, we all educate online. I am more and more cautious of what I put out there because you have no idea how a young clinician is going to take it, right? So you have to be very careful. I’m not kidding, you’re going to see some people on Instagram go bananas with knee extensions. They’ll hook up a chain to a VW bug and try to do knee extensions and try to move the car. You know what I mean? Somebody’s going to do that on Instagram and they’re going to say, “I read this paper that said to do it,” right? So you’ve got to be careful.
Mike Reinold:
Anyway, awesome. All right, great episode. That was a good one. I like it. We went a little over, but that’s good. It was worth it, that was a good one. If you have more great questions like that, hopefully we can shed some light. Maybe a little bit share our practical experience with what’s out in the research, I think that’s kind of why people listen to this podcast. But thanks again, really appreciate it, Dave. Thanks for the great question. Again, if you have another question like that, please head to mikereinold.com, click on that podcast link, and we’ll see you on the next episode. Thanks so much.
