Episode 228 | The One ACL Exercise Everyone’s Told to Do—That I Rarely Prescribe

What is up team? And welcome back to another episode on the ACL Athlete Podcast. Today, we’re getting right into it. I had a call with an ACler recently, where she shared feeling defeated about not being able to do a straight-leg raise at four weeks post-op. She was told by her PT, her physical therapist, her physio, that it’s an exercise she needed to be doing, week one.

It may seem like nothing to the physical therapist, but from an ACLer’s perspective, myself included, being that I had two ACLs. When you’re told this stuff, you take it as, like, okay, this is what I should be doing. And it’s interesting being on the other side as a physical therapist, especially with the number of injuries I’ve had, being a rehab patient myself, but also working with other athletes of different sports, different injuries, and especially ACLs. It is just interesting because from an ACLer’s perspective of doing something like this, it can feel like a Mount Everest, literally. 

I know that that seems extreme here, but especially in those first few weeks post-op, why? Well, you just had a major injury, and let’s even say there have been times since that. Now you’ve had a surgery, a major surgery, a reconstructive surgery where they took that ligament out and they put a new ACL in there. Whether it’s your own, whether it’s a cadaver, there is a new ligament in there. Maybe you’re doing this non-operative; therefore, you are post-injury and you’re trying to still go through this process. But if we’re staying in line with what typically happens, most people do end up having surgery and having an ACL reconstruction. With that said, you had the surgery, a major surgery, and now your quads are shut down from it. You have limits in your range of motion. This brings on a ton of pain and swelling, and you’re also fearful of doing anything to the graft and the knee. Yeah, I get it. Someone probably told you that it’s fine. You’re not going to do anything to harm it. But that doesn’t just necessarily make that go away, especially from someone who’s never been through this injury or recovery. 

I remember going through this, and even my PT was like, you’re not going to harm anything. It still makes you apprehensive. Because when you feel those sharp pains or when you think about just the nature of the injury, and when you think about the surgery itself, it’s just really daunting. It’s people’s first surgery, most of the time, a major surgery. And it’s the thing that you’re just like, I don’t want to mess this up. I don’t want to tear that graft. And it all feels so fragile, no matter what the surgeon says, no matter what your physical therapist says. And I even communicate and educate my athletes on this. But I understand this from the ACLer’s perspective, that that doesn’t necessarily make it go away. Because you’re told to eat healthy doesn’t mean you just change your eating habits. It is just innate in our body, and it is just the way that our logic and our brain work, and the association with this injury, and just some of the fear around it. I get that right. And so with that said, there are just a lot of things that the knee is dealing with.

And then the other additional piece to this is that maybe there was an autograft taken. You had a graft taken from either your quad, patella, or hamstring. An autograft, especially from the patellar tendon or the quad tendon, is going to have a harder time than a hamstring graft or an allograft, in terms of the extensor mechanism, or what we call the thing that extends the knee. It’s not just the quads. You have your patellar tendon, you have your patella, you have the quadricep tendon, you have the quads. It is this whole integration of a system, which we call the extensor mechanism. It all has been impacted, but of course, depending on where the graft was taken, not to mention the surgery itself. That’s where these details are going to matter. 

And another reason why every protocol can’t be blindly applied to every ACL athlete in the same way. And so these are important details for us to know, and for this particular athlete whom I was talking to. They had a quad autograft. She has an even bigger mountain to climb, especially post-op. This is something because of the graft and how it impacts the quads, and regaining extension is even more challenging. Plus, how a straight-leg raise could do more harm to the recovery versus help it.

What you will see is that in 95% to maybe 98% of ACL protocols, there are straight-leg raises, and that’s the go-to on there. After someone does, the starter kit of quad sets, heel slides, the four-way hip raises, maybe there’s some calf raises in there if you could put weight on them, and then you’ll have ankle pumps. And then guess what? There’s going to be a straight-leg raise, I promise you, on at least 90% to 98% of these protocols. Those are probably dated from 2001, and some that I’ve seen that are literally from the 90s. It breaks my heart. It’s given as the PT exercise starter pack without any thought given to any of it, to be completely honest.

I’m not here to say all these things are bad. These are all great things. We implement some of them. I’m not saying you need to throw that out and get all brand-new exercises. But the thing is that we just blindly apply it to everyone when it’s not very feasible to do that in a unique surgery like this. Because of the long recovery process, but also just the unique nuances of each person, the type of injury, the type of graft, and also just how they respond to the surgery itself. And there are so many factors, y’all. This is something that is typically from the PT, or it might be on that sheet of paper the surgeon gives you post-op, for some exercises. These are the most common things. 

I will say I do not prescribe straight-leg raises. I’m going to repeat this. If any PTs are listening to me and they do straight-leg raises, don’t take any offense. I don’t prescribe straight-leg raises for the majority of my ACL athletes. Yeah, shoot me. I don’t think the juice is worth the squeeze, to be completely honest. Don’t get me wrong. There is a time and place. I’m not saying a 100% time and I don’t speak in absolutes here. But with that said, I think that there is a time and place. I’ve given it to people where they might have super sensitive knees and they respond really, really well to straight-leg raises with blood flow restriction training, for example. We can get some load, we can have someone feel their quads a little bit and they have just a very, very tricky graft site. Or maybe they have a tricky anterior knee pain that they’re dealing with. Maybe some weird symptoms in the knee that anytime we go to load the quads in any particular way, it really hurts. We want to add some load and we want to add some fatigue to the quad muscle groups and what do we do? Maybe we throw some BFR on there and then therefore they get a little bit of a stimulus where that quad can work a little bit, with a straight leg raise. This might be one exception here. 

Another situation might be they’re dealing with patellofemoral pain issues that is extremely sharp. We’re trying to find a starting point to add some activation and some load in a safe way. And then there might be certain issues where someone has a very high cartilage sensitivity. Maybe they had a replacement, or maybe they had a graft taken, whatever that might be. There might be a time and place for this depending on the restrictions post-op. But this percentage is super small and likely doesn’t apply to 95% of ACLers. Probably, most of you listening, and most of you listening are probably like, yep, I got a straight-leg raise, or I was told to do straight-leg raises and I’m not here to say that this is wrong. Don’t go running to your physical therapist and say, Ravi says straight-leg raises are bad. I don’t need to do them. But just hear me out on this episode and maybe the cost-benefit of doing straight leg raises. Again, I’m not saying 100% against the movement, it’s just a time and place.

The thing that I hate the most is that it’s what’s been done and we need to change this big time in ACL rehab. It’s the reason why we are where we are with high re-injury rates and low return-to-sport numbers. What’s been done is not working. And for some reason it continues to be done. And I think this is a bigger problem from like a system, education, all these different standpoints that I don’t want to really bore you guys with today. But really that’s the thing that we really need to shift. Instead of just complaining about it, I want to educate you guys on why this might not be the best case scenario for you. And whether you are a physical therapist, athletic trainer, an ACLer listening to this, this is something that I just want to share with you, just my take on it.

My point today is to defend why I don’t think it’s the best exercise for ACLers, especially early in the process. And then once we’re late in the process, it probably doesn’t really have a lot of carryover, but let’s get into it. This is going to be my own personal opinion. As I shared, if you’re doing them, don’t go to your PT and say, we got to stop. Hear me out, and let’s make sure that this is a situation where it can help guide the timing of it and also just understand the potential value of its use if it’s being used in your ACL rehab.

First, I would like to state that no one should be doing them if they are outside of post-op phase ACL rehab. I’ve had people come to us three months out, six months out, still doing them. They might have some issues, sure, but it’s not warranted for their case. And they’re like, I’m still doing straight-leg raises at three months, six months out. They’ve been doing the same exercises for three months or six months y’all, same thing. Straight-leg raises are a very low-level exercise for stages like that. I’m not saying that at the beginning of this process, it’s not challenging because it is. I remember trying to do my first straight-leg raise, and I was trying to own it. I remember it, but I remember my knee kept trying to bend, and I kept fighting it and fighting it. And I was like, oh, I got it. And my knee would be slightly bent as I did it. And later, after working with ACLers and going through this process, I started to realize, wow, like what was the carryover from that? And so we’re going to unpack this a little bit. 

When I hear about people three and six months out doing this, I do die a little bit inside. And don’t get me wrong, this can be a starting point exercise. But it is not a great exercise for building strength. And there’s nothing wrong to use it as an assessment, often used by PTs as what’s called like a quad lag test or a straight-leg raise test. Seeing if you can activate your quads and keep the leg hyperextended and straight as you lift it in the straight leg raise versus maybe there’s a lag where that knee bends a little bit and doesn’t stay straight. What does that tell us? Basically that you cannot keep your knee straight and keep your quads active and access knee extension against gravity as you go to lift it. That’s information for us, yes. What’s happening when you do the straight-leg raise, that’s what’s going to be really important here, and that’s going to help to tackle the importance of using it in ACL rehab or not.

There are two joints that are moving during a straight-leg raise and that are active: hip flexion, knee extension. Those are the two primary movements that are happening. Your hip is flexing while your knee is staying extended. What muscles control this movement, hip flexion? That’s going to be your hip flexors, so your iliopsoas, that’s going to be the iliopsoas major and your iliacus. So these are the primary hip flexors. Then you have your rectus femoris, one of our four quadriceps muscles. This muscle is also a two-joint muscle that crosses the hip and the knee, so it helps to flex the hip. We got hip flexion and extend the knee, so it could do two different things. The TFL and sartorius may also help in hip flexion. There are some other muscles that may help assist with hip flexion, but these are your primary go-tos that are going to be responsible for flexing your hip, aka think about bringing your knee up, and being able to bend your hip. 

And then we have knee extension, so we have your quads. That’s going to be your rectus femoris, as I just mentioned, going from your hip down to the patella. And then you have your vastus medialis that could often be referred to as the end little VMO area, that a lot of people try to isolate. Side note: you cannot isolate this muscle. It’s the innervation of all the muscles and we can’t isolate different ones, with externally rotating and doing a straight-leg raise so that is not a thing, even though that is in the PT world. But the vastus medialis (VMO) is the extension of that. Vastus lateralis is the lateral muscle group of the quads and the vastus intermedius is deep to rectus femoris.

I remember going through the anatomy lab and going through all of this, and I was so fascinated doing dissections and being able to see all these different muscle groups and the interaction, the innervation coming into the different motor points of the quad underneath the muscle. It was super fun, y’all. It just gave such clear insight into the way that our muscle groups are connected and work together, and also separated, and do their jobs. 

Here’s the problem: it’s an end-range exercise for your quadriceps, so you’re not getting much strength development from it, especially with the link tension relationship of the quads being very poor in this position. It means it can’t really produce a lot of force here. When we think about, if we interlock our fingers here, if you take both hands in front of you and you were to just like hold ’em out as if you had like counted to five on both hands, and then if you interlock them between the gaps with each other. So what happens is that with link tension relationships, there is an optimal link tension relationship for every single muscle group. When we are basically interlocking our hands and they’re as tight together with eliminating the majority of the space, that’s not a great link tension relationship. And when we’re at the very edges of it and see a lot of space, there’s not a lot of link tension relationship. We want there to be an optimal overlap here, without cramming each other, to produce the most force. That’s how our muscle groups produce force is through that link tension relationship. We want optimal positions, and that’s typically going to be when your knee is around a 60 to 70 degree range of flexion. That is your strongest position where your quads can produce the most torque and force out of that muscle group.

When we’re at the top of a knee extension and when we’re at the top of a straight-leg raise, we are at a very shortened position of that muscle group. And so then therefore this is not an ideal place to produce a lot of force. That’s an important key factor here because that’s going to also dictate, well, what’s our goal with the exercise? It’s on the list of exercises to do and accomplish. Also, sometimes, given as the goal for you to get off crutches. That’s the biggest thing here, on the protocol. And a lot of times, PTs will utilize it to get you off crutches. The athlete themselves feels forced to do it. I think they’ve got it when they don’t have terminal extension and are just making matters worse, to be completely honest. It just really bugs me whenever it’s especially given in week one, because people are just going to be really challenged with this. Now, don’t get me wrong, there are some people who will get this and it’ll feel great and it’ll go smoothly, and if that’s you, then awesome. But I would say for majority of ACLers, it doesn’t serve them super well because most people aren’t just crushing it, week one, get their heel pop, full, extension, no pain, no issues, and they’re doing it smoothly. The thing is people will often compensate to complete the task. It is a goal-oriented feel good thing.

A lot of times what I see is that people will rotate the leg out externally to bring the other muscle groups to help them flex the hip. They might use some momentum into it, where they rock their body, may extend from the back. They may hike their hips up. And the most common one is typically that someone will try to do a quad set, and then as soon as they go to lift that leg, that knee bends a little bit, and then there’s a little bit of a quad lag, and it might be just ever so slight. It’s not full extension or that hyperextension where you get that heel pop, and it stays there. Typically, what happens is that as soon as you go to lift that leg and it’s unsupported, it’s going to have a slight bend in it. And as soon as that bend hits, that’s going to change the intention of the exercise, and you’re not getting out of it what you need.

The thing that I always want to ask, and we always have to ask this with any type of exercise or movement: What is the goal of the exercise? What is the adaptation we are looking for? Any exercise should always have a goal of some sort of outcome, whether that is looking at the range of motion. Is it going to be based on a skill or position? Is it going to be based on strength? Is it going to be based on some dynamic task? There needs to be some sort of goal associated with this. What adaptation or quality are we trying to get out of this? I like to always ask what problem we are trying to solve with an exercise. Is it the terminal extension range of motion with the straight-leg raise? Is it a quad activation thing? Is it a quad strength thing? Is it hip flexion strength? Most PTs would probably say all the above. I’ll be honest, I bet most PTs don’t really give it much thought because it is typically just the thing that most protocols and PTs have been taught over the years to just give any post-op knee, especially in ACL. Quad sets, straight-leg raises are the number one and number two exercises, I promise you. Short arc quads might be number three. And again, nothing necessarily wrong with utilizing some of those, but time and place, and making sure people are not doing it for too long or too early. 

Let’s break this down based on what I just said. Is it the terminal extension range of motion we’re trying to get? Maybe. But why not pick an exercise that isolates this and keeps the hip out of it? If terminal extension is our main goal, why do we need to complicate it by adding the hip into the mix? Why can’t we just focus on end range extension and really isolating that and nailing that, because that’s the problem, not hip flexion. Quad activation? Maybe. Same point as above. Why not just pick something else that has more bang for our buck and avoid maybe that compensation that a lot of people will deal with? What about quad strength? As I mentioned, this is not an angle you want to build quad strength in the best. It’s a very suboptimal position given the link tension relationship of the quads. As I mentioned, you want to be around 60 to 70 degrees of flexion to really maximize force output and optimal link tension of the quads. Usually, what we will do is we’ll give athletes once they can get comfortably to 60 to 70, or ideally 90, just because it’s a little easier to set up. Because that’s going to help us get in a solid link tension relationship, and easy to gauge, set up, and repeat on their own. We’ll have them do isometrics in these positions versus being focused on doing it in a straight-leg raise position.

Another reason why we give NMES in a 90-degree flex position isometrically? Because that is going to allow us to get the most out of our quads. Yes, we’ll still do it in a heel pop or extended position to work on terminal extension to own that range of motion. But our goal there isn’t “strength” or building force output or torque, it’s more to make sure we can own that range of motion. And you can argue that yes, you could do that with a straight leg raise. But I would argue against it because unless you are locking in that terminal extension, you’re primarily going to be doing more of a hip flexion-based movement than it is beneficial to knee extension.

Now, hip flexion strength? That was the other thing that I mentioned. Why focus on this right after ACL reconstruction would be my question. This is something that the hip is already working overdrive to lag that leg around because your knee isn’t going to do its normal job. The number of times I’ve seen athletes with hip pain or tendonitis because they’ve been doing so many straight-leg raises from their other PTs with a bent knee, and then combining that with moving around on crutches. It doesn’t make sense. We don’t really need to worry about hip flexion strength, especially when we are starting out post-op ACL. 

One day, maybe I’m wrong and change my opinion completely, but for now, I feel very strong about this, and the prerequisites have to be there, aka, we need to make sure end range extension is there and active quad control. Meaning, we need to have a heel pop before doing this movement. And the thing is, most a ACLers don’t. It’s just not there in that first week. It’s not always there in that second week. Are we aiming for that? And do people sometimes get it? Yes. Especially, with nowadays, a lot of people are getting quad grafts. It’s so hard, y’all. It is not as easy as you think because extension range of motion is harder to get back. People deal with more pain and swelling. Their quads don’t want to activate, and they feel that donor site where that’s taken and dealing with AMI (arthrogenic muscle inhibition) with swelling there, with that surgery, with the injury, it’s just not super easy to do. I think it honestly sets our athletes up for failure whenever we are giving them straight-leg raises and asking them to do this, especially if it’s not executed well, and especially if they just don’t have this prerequisites there. If you don’t have your extension back and you can’t pull on it with a strap passively and get there and you can’t squeeze and hold that, then I promise you, when you go to do the straight-leg raise, it’s going to be slightly bent and it’s not going to feel great. We need to make sure we check those boxes if you are going to be doing it.

In my opinion, a straight-leg raise is going to be better as an assessment than it is an exercise itself due to just the nature of the movement itself. And throwing ankle weights on it for weeks and weeks doesn’t help it or make it any better. Usually, by the time someone hits a straight leg raise, it’s time for them to move on to more challenging exercises, of course, with those exceptions that I had shared earlier. If you could find yourself in this position. Getting your extension back or activating your quads and you’re also doing straight leg raises, I think this is actually playing against you. Instead, my suggestion is to isolate these components and work on them on their own. Own them really well. Get your heel pop really solid. Be able to work on activating your quad. Get that terminal extension. Own them. And then yeah, sure you can attempt a straight-leg raise, 

But in reality, you should be moving on to other things, given the poor utility and more downside than upside for the movement and value itself. And I’m going to stress this, especially with people with patellar tendons and especially quad tendons, it’s just going to be a challenge and I don’t think it’s worth it. When a knee is slightly bent and you go into a straight-leg raise that it is not going to really have much carry over and you’re actually going to be putting more stress on your patella, your quadricep tendon and your patellar tendon and you’re not going to get that much quad work and your hip’s going to be working and doing most of the work. Even that isometric knee strength position, we were hoping to get something out of for this movement. There’s no value in it. Therefore, you’re going to put more strain on those tendons and the patella, and that is not going to be super helpful, especially in early post-op when you’re trying to get symptoms to calm down. When you’re trying to get these tendons to behave really well, when you’re trying to get that extension back and when you’re trying to get your quads to wake up, that’s just gonna play against you. 

This is probably something I’ll have PTs come at me because they’ve been giving this out for years and feel as valuable. And, hey, you can do that. But I first challenge you to dive into the value it is providing when we break it down from what we’re hoping to gain from it and the problem we are trying to solve by prescribing it. Please just take a second to think about this exercise, and I’ve given this so much thought over the years because I think about ACL rehab way too much and it occupies way too much brain space, and I just have thought about straight-leg raises. Just through the years, and as I first started, I started giving it to people, and then I was like, man, why am I giving this to people? And I started to realize I was just giving it because that’s what it was typically done. And then I started to realize, oh, maybe we can accomplish these goals in different ways. And maybe it’s also not setting these people up for just doing something 80% when they need 100% to make it truly effective.

I hope that this is helpful y’all. If you have any questions about this, please let me know. Happy to break it down even more. I did not expect to talk this long about straight-leg raise, but I felt terrible for this athlete because she just felt so disappointed. I was like, that’s just a PT situation where they shared something that she needed to accomplish in week one, post-quad tendon. I was like, that’s not happening. And I don’t think it’s valuable. And especially with a quad tendon, we want that thing to behave and be able to mitigate that pain, allow it to just do its thing, especially in the first six to eight weeks. I don’t think it’s valuable, and I think that we can empower our athletes in different ways. I don’t think that this was a strategy to go about doing it. If you feel like you are “failing” because you haven’t hit your straight-leg raise, dump it. And then, therefore, find actual objectives and benchmarks that are going to feel meaningful and exercises that cater to those things that are going to give you the best bang for your buck. I hope that this was helpful y’all. Please, let me know if you do need anything, have any questions. Until next time, this is your host, Ravi Patel, signing off.