Episode 195 | One Common Mistake ACLers Make When Working on Knee Extension

What is a team and welcome back to another episode on the ACL Athlete Podcast. First, I just want to stop for a second. I want to say thank you to all of you who have reached out and just said how much they appreciate the podcast and how it’s helped you in your journey. I get messages every single week, and it is awesome to hear how you guys are putting this stuff in play, how it’s been helpful, whether you decided to go in a different route with your physical therapist. Maybe it is finding a second opinion, may be finding some testing for you or just the mindset pieces that I’m hoping that you’re able to pull away from these episodes. Please keep the messages coming. 

As you know, in the show notes, there are opportunities and ways for you to send me a direct comment. It’s nothing where I know what your number is. You can text it directly to me. You can send me a message through Instagram, email, and I get all of these. I read all of them and I replied back to all of them. I just want to say thank you so much because I have so much gratitude towards you guys and this space. And as we just continue to try and move the needle and help as many ACLers and just the whole profession of physical therapists and coaches who are working with this and surgeons, we’re all trying to do the thing. 

I appreciate all of you guys and I’m going to continue to try and put out as much as I can to help you guys through this process and just share my experiences. In that way we can, one day say maybe reinjury rates are dropping and that we can get people back to sports without there being this fear around this injury and there’s better care serving all of you guys. Thank you so much!

Now, onto the episode for today. After an ACL injury and surgery, one of our top goals, if not the number one goal, is to regain knee extension. What I often share with athletes is the heel pop. That is essentially a test for you to be able to do, to assess and see, am I able to do what I need to do with my knee extension? That basically clears two things for us. One is making sure that you have your matching knee extension and that your quads are active to do it. Our goal is hyperextension matching the uninvolved side outside of someone who is extremely hypermobile and has -15 or -20 degrees of hyperextension. And there are other cases as well, but for 95% to 98% of you guys, you are going to be aiming to match your extension as the other side, assuming it has not been injured. The way you can do this is essentially get on the ground, or on a table and you’re essentially going to use your uninvolved side as your target and you’re going to do a quad set. The goal is to try and lift the heel and the foot. You’re almost bringing your toes towards your nose and you’re doing that quad set, which is the staple of every single basic exercise given after a knee injury, but especially after ACL injury and surgery. It’s on that post-op sheet of paper that you get. It’s the number one thing that your physical therapist will give you after a knee issue and especially after surgery and injury. So that quad set is going to be essentially what you’re going to do, and that’s where we’re trying to aim to get that hewl pop. If you do it on your uninvolved side, your heels should kind of lift off the ground and there should be a little bit of space underneath the heel and the floor, or whether it’s on a table that you’re sitting on, but that should allow your quads to activate and your heel comes off the ground. The back of the knee is flush to the ground, ideally. But we are not kicking in with our heels as well, while we’re keeping the back of the knee down and doing a quad set.

Again, as I had mentioned, the goal of this quad set is always two-fold. One is to wake up the quads after this injury and surgery and get them active and firing. We want to wake them up because we know that they can get kind of sleepy in this process, especially after the surgery. And then the other thing is that we’re also trying to regain that full knee extension. So that’s number two for that quad set, and the goal and the purpose of it. I see often that what is overlooked and butchered a lot is this movement, and you think it could be straight forward. But this could be something due to poor guidance on how to do this exact movement. And don’t forget, we’re coming into this with kind of our brain and muscle disconnect, especially with the knee we’re dealing with pain and swelling. There’s a lot of pieces that are in play. 

And I remember from both of my ACLs, immediately after surgery, it was challenging to get that quad set. There’s apprehension. There is the pain, of course. You’re just like, am I going to mess something up? You’re also dealing with inhibition of the knee itself, too. This is something that I think for, especially physical therapists who haven’t gone through a knee injury like this and who have not had to deal with something like this, like an ACL reconstruction and it can easily get overlooked as a very basic exercise. How can you mess this up? And looking at it, sure, but there are so many people where it can be really challenging. This comes back to, is it because of poor guidance on how to do the movement? Maybe it’s the queuing of it, understanding the setup of it. But it can often be overlooked because of the simplicity of it, or maybe the PT doesn’t have enough time to look at the details of it, or how you’re firing and doing the actual quad set. But this is something that I think is important to slow down and make sure you’re doing well and doing it right. 

With that said, the other piece of this too, could be maybe you are getting good guidance on it, but you are dealing as the athlete and ACLer with swelling, with pain, with inhibition, with apprehension about messing something up, or just moving the knee itself. You just had a major surgery, so that’s warranted. And that is totally normal to feel. What I want to make sure with this episode is to point out something that is a common mistake. I see that it doesn’t get discussed very much in this space. I think is just like, hey, work on your quads, work on your extensions, hang it up, do some bag hangs, do all these different exercises. I want to point out some things that I see that can be hopefully helpful for you as an ACLer, especially for those people who—it might not just come back naturally in those first couple of weeks. Dealing with extension, maybe it’s taking its sweet time to get back and the quads are staying a little bit more asleep. So then therefore, this especially applies to you guys because there are people who get extension right off the bat. They don’t have any issues and that’s great for you. But there is also a very large group of ACLers who struggled to get extension back. And that could be for a number of reasons, from the injury to the surgery, to the graft type, to maybe there is a nerve block, to maybe there is some other neurological factors in play. We know that the knee and the quad shuts down through AMI (arthrogenic muscle inhibition). There’s some sort of like weird brain muscle knee connection that it’s almost like the battery has been disconnected. And there’s even a subset of these people. Therefore, I do want to make sure that it’s understood. 

Yeah, we have an expectation to get this ASAP, but it can take some time. I want to make sure that you’re equipped to know one of the things that look out for, especially if you’re someone who maybe doesn’t get the extension back ASAP. You are fighting really hard to work on it, work on these quad sets because I’m sure you will do hundreds and hundreds and thousands of these over the course of ACL rehab, especially if you’re trying to get your knee extension back. 

The common mistake that I see when athletes are especially doing a quad set, specifically, working on this heel pop, trying to get that full knee extension, getting the quads active, is that their hamstrings and glutes can sometimes take over. If someone is having a harder time with extension, the movement itself can be a little bit deceiving to them and potentially the PT too, thinking that they’re getting a good quad set. And that extension, when in reality, they’re actually kicking on their glutes and hamstrings while some quad tone might be showing up. This is especially true for my ACLers who have maybe more of a little bit muscular built, the defined folks where obviously, you’re a little bit leaner. This is something where I noticed where they’ll go to do a quad set or they’re working on this knee extension and it’s something where they’ll start to fire their glutes and hamstrings. I’ll see, they’re kind of hip kind of lift. And when you do a quad set, you’ll kind of see some movement lift in that thigh and in the glute a little bit. But that’s where it’s challenging. We got to make sure we covered the details of this and what’s firing and what shouldn’t be firing. Because what ends up happening is that glute and  hamstring kind of contracts with it and the quad is not completely asleep. Maybe you have been working at it and it’s kicking on a little bit. You feel like you’re doing it because you don’t really know what it should feel like. It’s more of firing at 50% of its capacity. When you’re doing that quad set, you’re feeling it maybe kick on there’s a little bit of tone, there’s a little bit of firmness, but it’s not the same as the other side. But you see the leg lift a little bit in terms of the thigh itself. What I will notice when I observed my athletes is that this is something where, if we don’t correct this, they’re essentially digging a little bit, especially the heels contact with the ground or with the table, they’ll  dig a little bit their heel, or maybe some of their calf, the back of the leg, as they’re trying to fire and push the back of the knee down and is kicking on the hamstrings and glutes. So what is causing is co- contraction. Imagine you’re looking at someone from the side, they’re laying on a table and when they go to do this quad set, they’re trying to essentially keep the back of the knee down while the bottom of the heel lifts and you start to see a gap underneath it where the heel pops up. 

But what ends up happening is that if athletes aren’t queued or if they’re not appropriately corrected on this, they’ll dig the back of that leg down, especially the heel in the back of that calf. And that hamstring and glute, what we’re essentially doing is doing an isometric at our hip. And so that’s creating hip extension. It’s firing our glutes, firing our hamstrings a little bit and it’s co-contracting along with maybe the quads are kicking on a little bit. But the thing is, it doesn’t feel like it’s fully kicking on and it doesn’t feel like the hamstrings and glutes are fully relaxing. This is something that I do see doesn’t get corrected by some ACLers who maybe come to us a little bit later, especially with knee extension issues, maybe an overly tight hamstring and maybe it is something where they’re still limping with their gait. This is something that’s always interesting because maybe they’ve been given the past and move on and start doing straight-leg raises and all the other things that come along in this process. They’re like, “Oh, well, yeah, the extension’s there, but in reality, it’s not.” The same people can sometimes think it’s fine and normal. And they’re the ones who do have this extension and quad-activating issues later on down the road. 

And the other thing that I’ll see too, is that sometimes when I ask them, an ACLer who’s six months out, dealing with extension issues, they might recruit their hamstrings and their glutes whenever they are contracting their quad in certain situations, where it shouldn’t be. The firing patterns, almost the brain knows at that point, “Oh, I need to go into extension. I’m going to fire my glutes and hamstrings and try to kick on my quads a little bit too.”

With that said, I think trying to focus on this isolation piece, and really being able to clean up this error can help a lot with people feeling their quads a little bit better, getting this extension back to matching the other side. This is one thing that I want you guys to look out for, especially if you’re an ACLer who’s listening to this, and you’re struggling with your extension. I’m not saying this is going to solve all of the extension problems in the world for ACLs and knees, but this is something that I see more often than not when someone is not corrected or dealing with extension issues. You want to make sure you get that passive range of motion. Being able to lift it up passively, where it needs to go. But especially with the quad set, being able to make sure that you can lift that heel up and get that heel pop, and not kicking into whatever surface you’re on. 

One of the tricks I like to do with this is removing the tactile sensation behind the heel or behind the calf a little bit where you might be digging in. We’re trying to limit the ability or the input of the hamstrings and the glutes. The way we do that is we need to remove, especially if you’re on a table, you might be  digging your heels down as you’re doing a quad set, trying to activate that quad. What I’ll do is have the athletes actually scoot off until half of their Achilles or even to the top part of their Achilles will be on the table and their heel is actually off the table. What I challenge you to do here is actually do this on your uninvolved side. Have both legs hanging off the table and the back of the Achilles kind of low ankle socks would be. You’re going to essentially lift up the uninvolved side and you should feel that get flushed with the surface and lift that heel up, and you’ll feel that quads contract and squeeze. You’re going to try and do it with the operated side, the injured side and do the same thing and see if you can get that to match up. What I find is that if we remove the heel or that tactile sensation on the back of the heel, then that’s going to help with reducing the activity of the hamstrings and the glutes. 

I did a video on this on IG, showing one of my athletes actually doing that. What we did was actually have him slide off the table a little bit and queued him a little bit, of course, but reducing that tactile sensation made a huge difference. I think this is something that does get overlooked and you might end up getting the right firing pattern. But if you’re not mindful of it or intentional—I’ve seen athletes who—they get at one session and they come back in the next session and they’re still kind of reverting back to that firing pattern. Therefore, we need to clean this up because we want to make sure repetition to repetition is consistent session to session. Especially at home, man, you’re hitting a lot of reps of this stuff.  You are putting deposits into the right type of movements versus choosing to go through it, but maybe it’s not as best as it could be. This is something I want you guys to look out for, especially with the quad set and your knee extension work because there is not a single human who will walk this earth if they have a knee injury, if you have a ACL injury and surgery. You will hear of a quad set or maybe in a different country it might be referred to something else, from a terminology standpoint. But it is one of the most basic exercises given in any single post-op sheet of paper that has an exercise on it. It is going to have a quad set on it. Therefore, we want to make sure if we’re using it, not a bad exercise to get started on it.

 But with that said, we want to make sure we are very intentional about the details and the way we’re executing it, because it could be the difference between you not getting that extension in a couple of weeks and maybe you’re still attacking it three months later, six months later. Just the nuances of this process, I want to make sure I share with you guys and see what I see with my athletes. How we can clean this up. Check out the video. I hope that this is helpful for you. If you have any questions, you have so many different mediums to reach out and find me. If you guys have been getting value from this podcast, I ask you one favor. Please rate us, please share that rating for us and that will be so helpful, whether you’re on Spotify, Apple podcasts, whatever it might be. It goes a long way and it helps us reach more and more ACLers—and that is the goal. How can we shift this landscape and the problems we’re dealing with by continuing to educate. Not only other professionals who are going through this process and being able to work with ACLers, but it’s also you as the ACLer yourself, putting you in the driver’s seat, putting you in control of this process. So that’s what my goal is with this podcast.

I appreciate all of you who have been on this ride with me. If you want a chat, if you need any help, reach out to us. Otherwise, I will catch you guys next time on the next episode. This is your host Ravi Patel, signing off.