Episode 180 | Testing Frequency and Structure in ACL Rehab

What is up team and welcome back to another episode on the ACL Athlete Podcast. Today, we’re answering the question: How often should you test in ACL rehab? One key principle we should establish first: testing is very important and very necessary. But a few things I do want to mention about this. There are places that “test” but maybe don’t test the right things. What we need to do is we need to determine what’s important, then measure it, then do something about it and then repeat that cycle, in terms of making sure that’s still important, measure it, change it, impact it. And then it’s kind of this feedback loop, usually via some type of test or assessment, is the way that we’re going to measure it. 

If we’re in school, we’re usually taking tests in order to assess or determine have we taken on the knowledge and have we retained it? Probably temporarily for most of us. But we are taking that knowledge, we are applying it to a test. We get a grade on it, so that helps to measure it, to assess our love of competency of that. This is something that we want to keep in mind with this, because it’s not the other way around with ACL rehab. Just because a test is available, it doesn’t mean we just do it; just because you have force plates available, it doesn’t mean you have to use the force plates. We need to make sure that why we have force plates. Well, we got to figure out what is it that we want to assess that’s important for us to use the force plates for. I know most situations, people don’t have force plates, but this applies to anything. 

What’s the reason we use a goniometer to measure range of motion. Well, it’s because we need range of motion, a certain amount of extension, a certain amount of flection in order to make sure you’re able to walk, run, squat, all the things. It’s a prerequisite needed, so basically we need that range of motion. We need to measure it via a goniometer. Typically, other different like methods, if you will, to measure, but that’s going to help us. If it is sure of what we want, then while we’re going to do something about it, to change it, which is usually a goal. We’re working on range of motion pretty early. We want to make sure that that stuff is the foundation of this, and not just leaning on tests just because it’s a test. We need to connect that meaning to behind what we are testing. 

Matt Jordan has this great framework that I love. It’s determined what matters, measure what matters, change what matters. I’ll repeat that again. Determine what matters, measure what matters, change what matters. It’s not measured determined then change; it’s going to be determined what’s mattering so what’s important, measuring that thing and then changing that thing. And then this kind of this feedback loop we’re always going to make sure is that things still important. We’re going to measure it and then we’re going to change it until it’s no longer relevant or we’ve met this certain KPI or a threshold that we’re looking for. This is rehab and performance in a nutshell, and a foundational framework for us at the ACL Athlete. 

If you look at businesses, this is something that they use to write. It might not be these three steps, but they’re doing it inherently. They’re setting up KPIs for certain targets, whether it’s financial, maybe it’s clients, whatever it might be, maybe it’s for marketing. But you’re going to try and figure out what those metrics are. You’re going to measure it and then you’re going to try and influence those things, especially in the positive direction. You’re also going to influence things if it’s going in the negative direction. This is something that’s really important to help anchor this conversation around how often you should test. 

If your PT, coach, surgeon thinks an MMT or a manual muscle test. If you’ve listened to this podcast before you’ve heard me talk about this, this is where you are seated on a bench or a table, whatever that might be, usually the treatment table. They stabilize one hand on top of your thigh and then the other hand is stabilizing at your ankle and they ask you to kick out as hard as you can. This is called a manual muscle test. We’re basically measuring “strength” that you’re kicking out into that person’s hand. Now, this is not a measure of strength, although there is this thinking that it is a measure of strength. In all honesty, it’s just a convenient way to see if someone can kick into your hand. That’s really it. I think it’s just quick and easy, it’s simple. I think that a lot of people, it just saves time, but it’s not really measuring strength. I think that’s the biggest thing to mention here.

People will literally come to us and say, yeah, I’ve had my strength measured. And then we ask them how, and it’s through this method, if you will. And the funny thing is, is that this was invented during the polio epidemic, whenever people were obviously losing control of certain things. It was just a test to see, can they move that and kick into something or move their arm or whatever that might be. Physical therapy has adopted this five-point scale grading system with it and it’s not valuable for strength. It just lets us know you can kick the thing or move it, but that’s about it in terms of it being a true strength measure and that scale—not helpful. This is something that I think a lot of medical professionals utilize as a quick and dirty test. I just want to make sure that that is clear. It’s not necessarily something that’s going to give you a value to know how strong you are. It’s just basically a measure of like, can you kick out? And then also, how strong is the other person kicking against you and resisting you. Think about the linebacker versus the high school soccer athlete versus the swimmer versus, well, I guess swimmers don’t really tear their ACL… This could be literally anybody who is sitting there, but you think about the variety of populations who are dealing with this injury—different ages, genders, backgrounds of training. And then you got to think about the other person who is actually resisting. That’s going to be the medical professional or whoever’s doing it and it’s basically how strong are they? It’s just this kind of like tug of war. 

My good friend, Wesley Wang, had mentioned is basically like you picking somebody up and guessing how much they weigh. It’s how strong you are. But then also it’s just a general measurement of like how heavy are they? You don’t really know. And it’s always going to be relative to each person in terms of your perception of that. So that’s an MMT. You guys love this lesson on this, even though we are talking about frequency and how often the test, but I think this is important. 

The other thing I’m going to talk about is hop tests. This is something that is used a lot. People say is a return-to-sport test. They’ve done their return-to-sport testing. And all they did was a hop test, single-leg, crossover hop, a six meter hop, side hop maybe, and they’re not returned to sport tests and it’s a problem. I think the thing that I want to share here is that, they are giving this assumption that they’re testing things when they’re really not testing things. I think that’s the main take home here is that we got to make sure we know what’s important and then test that, not just use these tests that maybe have been used in the past. We want to make sure we update that, thinking that model, that framework to make sure it is doing justice for the athlete. I think that’s the biggest thing here with the hop testing, it doesn’t really assess readiness when you actually think about  if an athlete is going to back to play basketball, soccer, ultimate frisbee, skiing, do you think that hopping for a single hop or even like a few hops forward is something that’s just going to give us a good idea of how this athlete is going to move in a dynamic environment and space and be able to do that—it doesn’t. 

When we look at the actual research recently, Kotsifaki, is from Aspetar. She has done so much incredible research and a leading force in this. But has studied the hop test extensively and basically showed any horizontal hop tests for the most part, you can get the same distance, but you can also compensate. It gives you a false sense of how you’re doing. We have to actually look at how the jump looks. The other thing too, is that it doesn’t really measure the function of the knee because a lot of contribution come from the hip and the ankle. I digress but this is something that you probably, you know, maybe have been exposed to maybe not, especially if you’re an ACLer. I think it’s just important to know, is the test valid and reliable? That’s the main point. I want to make sure and making sure we come at this from a very helpful framework and one that is anchored to something that is going to help you moving forward in your ACL rehab process. It’s going to always be based on what we’ve determined is important. 

Some of those buckets being: range of motion, isolated strength, integrated strength, power, reactive strength. And then we’re thinking about dynamic tasks like sprinting, jumping, cutting. There are a lot of different domains that we’re looking at and qualities of athletics that we have to build athletes back up to. It’s not just as simple as a forward jump or even just kicking into someone’s hand. There are a lot of different avenues that we need to look at. We need to have some quantitative aspects and qualitative aspects that we’re measuring from these different movements and measuring that and making sure that that is applying to what we’re doing moving forward. 

Now, let’s talk about how often the frequency of testing, which is why you’re here. I have just complained a little bit about some of the misnomers, but I think it’s important as I always share for you guys to know that there are things in this space that clinicians, coaches, surgeons will say like, oh yeah, you’re good. But we need to make sure it is aligned with research, with the science, with what we know about performance and this ACL rehab process because this can be the difference in athletes going back to sport reinjuring and not, to be completely honest. Also, not to mention the performance level that they come back at. People always feel like they’re off or they’re always having to use the other leg or all of these different things. And a lot of times it comes back to maybe not being tested the right things if they did have some testing played into their process. A lot of times it’s not even there, there’s the gap, but here we are.

Now, let’s talk about frequency. There’s no perfect answer here. If it’s done what you will notice, in a general theme, the most common thing to see is three months, six months to nine months, if you are lucky to get that. And of course, it just depends on what you’re getting at those timeframes.  I know surgeons here and even practices here where they’re like, all right, we’re going to test you at three months, six months, nine months because it just feels like this perfect timeline to give enough time.  That’s the frequency a lot of surgeons will see people in this process. Those are things to kind of keep in mind here. That’s a common thing. It’s also common to be sporadic. It’s very common for it to not be done in a lot of cases, depending on your rehab and physical therapy, your professional experience and if they are doing this very regularly. For the PT-ing and coaching, this does need to be more frequent. It’s very important that I stress this. It will look different with different phases and stages of the ACL rehab process and also what you can actually test at those certain moments. 

Let’s talk about time points. If you’re early post-injury or post-op, we’re going to be focusing a lot more clinical buckets weekly. We’re going to be looking at your range of motion, your flexion, your extension, how’s your gait looking, your effusion which is your swelling, your pain levels, your activities of daily living, maybe things that you were able to do versus not able to do. Those are things that we’re tracking. And we’re looking at these KPIs often, especially in the earlier phases of this, because those are the things that are the main limiters. In terms of strength testing, one thing that we’re going to look at is the uninjured limb, the quad and hamstring during prehab, if you can, as soon as you have the injury itself. I know this is the last thing that you’re thinking of. But if we can get that measure on the uninjured side, as soon as you get injured, that’s valuable because we could use that as a baseline as we move forward. Therefore, if that limb does get de-conditioned, we always have this number that we can always anchor back to based on when you did initially get injured. And so that’s our baseline in a sense. We would want to test that as soon as we can, if possible, or as soon as you see your physical therapist, whether that’s during the prehab process or maybe even post-op. You would want to try and assess that on the uninjured limb ASAP. I think there’s a lot of value in that to let us know, where is this limb at? But we want to make sure, especially if you are early in that process, that you’re not flaring things up. The last thing you want is a knee that’s injured. And then on the other side, your patellofemoral joint, your knee is uncomfortable. You’re dealing with toonies. This becomes a problem and it’s not worth it. So that’s where working with a qualified professional, who knows this stuff is very key. 

Post-op: You are going to be looking at probably around 8 to 12 weeks post-op, depending on the case, progression, pain levels and tolerance, also the graft type and any other particular things done in the surgery will play into this. We might hold things off a little bit. If the athlete has been limited, maybe they’re non-weight bearing for four weeks. This might slow things down a little bit. These are the things that we want to factor in. But a lot of times, athletes in terms of strength testing, the quads and the hamstrings, we just got to always ask, is it worth it? And of course, the further and further we get along in this process, that’s going to become safer and safer as long as we’re not dealing with pain and swelling issues that are dramatically influencing that. Because otherwise, it turns into, instead of a true strength test is just really a tolerance of pain that you can handle. You’re probably stronger, but the pain is the thing that becomes the barrier first, before you actually hit your peak strength. So that’s a tolerance to pain-type test instead. 

What we want to do is make sure we do this progressively. We’ve seen anywhere from 8 to 12 weeks and we will do that with our athletes. It’s important to have a regular cadence to retest. Well, we call serial testing, which can be even weekly. With strength testing, you’re not really going to do that. But with certain other tests, where it’s not as much of a stressful type test, you can do that more regularly. But it can be weekly or a certain cadence of every 2, 3, 4, maybe even every six weeks. In general, there needs to be some level of assessment and testing every four to six weeks. That would be my general rule of thumb. Every four to six weeks, there needs to be some type of assessment, evaluation. Let’s see where we’re at. This informs the plan is working, or potentially not, and future direction of programming based on needs. 

I just tell you this athlete I’m working with. They’re able to get isokinetic testing. They’re kind of leaving it to me of like, hey, when should we get our next isokinetic testing? I was like, well, we want to make sure we get this sooner rather than later, because I want to make sure what we’re doing together is actually targeting the thing that we’re working on, which is trying to get back quad strength. This is something that we want to make sure we have an idea of this versus allowing eight weeks to pass. And maybe it’s there, or maybe it’s so far away, but we’re dividing too many areas, and we’re not tackling the one thing that is the main thing. That’s why regular testing is so valuable because it is going to impact future direction and programming based on the needs and the results of that. 

When we structure this, you can look at this as a testing day. It could look as a testing week, it could look as what we call embedded testing which is where you’re going to just plug this into your programming and into the session without the athlete knowing. Of course, if you are a clinician or a coach, this applies more to you. If you’re an ACLer, it might just be something you plug in knowing this, but you’re just going to have this embedded into your workout. Let’s say for example, I have an athlete on their final week of their training block. I’m going to potentially have them do five repetition maximum of 90 to 45 degree knee extension on both sides and then I’m going to see, okay, well, can we anchor this to RPE 10? Therefore, we’re going to say which basically means go max effort for five reps and you’ve got to find a way that you can roughly do for five reps and no more than that. With that said, we’re going to try and find a way, and we’re going to see what is the discrepancy side to side between doing five reps in that partial range. And that’s allow us to anchor this process by saying, okay, go to failure. So if you’re doing five reps, you’ve warmed up to it on each side. It’s the appropriate timing for this athlete. They’ve been doing heavy knee extensions. We’re going to say, all right, go to five reps on each side, pick away that you feel like you can do and then you’re going to go to failure. If you overshoot that by far, that means you probably pick the wrong way to have been working out the wrong way because it’s too light. If you’re roughly around five reps and you have the weight for each side, then that seems to be more on target and that allows us to anchor this accurately to where the strength is for each side. 

The problem becomes is whenever we overshoot that in a sense where we end up doing 10 reps of the weight or 15 reps of the weight and that becomes a problem because you probably weren’t really working on strength. It was just some endurance stuff and that was time associated that you could have been working on really getting stronger, but that was just because the intensity and the weights weren’t anchored to the right rep, ranges and sets. This is something that I think is very important in terms of being able to do this. I love this with embedded testing because a lot of our athletes honestly don’t know, and it allows us to get a really solid idea where they are with certain movements. And that way we can use that as information moving forward within their programming. This is going to allow us to anchor that process to gauge our dosage more accurately to our top-end strength and to our capacities. 

Serial testing falls perfectly with this because we are just looking to continue to monitor things. It might be certain things like jump testing so that is something that you could probably test weekly, if you really wanted to because it’s not usually as intensive for people. Strength testing could be a little different depending on setup and time sensitivity. The knee cap, is it really sensitive to that? There’s a lot of factors that you have to play into this, but it could be maybe every four to six weeks. It could be every two, three weeks depending on the athletes. It could just be a quick and dirty test that you do at a regular cadence. There is a lot of value in structuring it, but just know you have options there. You can do the testing day, the testing week, embedded testing, allowing it to get anchored that way. They’re serial testing, which is the frequency and flow of it. Those are just different ways to look at it, in terms of structuring along with why I mentioned earlier of the different time points of when and how often the tests.

Now, it’s important to know: don’t test just for the sake of testing, testing influence change. Make it objective, check our biases which is really important. Otherwise, if we’re just like, all right, it’s subjective, just like the MMT where you’re kicking into the hand, it’s like to tell what we want to tell. Our biases play into this. If you have a clinician that’s hoping you getting stronger, maybe they might lighten up a little bit. And you’re able to kick out harder and you’re like, oh cool. You’re stronger. But how do you know because there’s no number associated. This is where numbers are helpful from the ACLer to the clinician, coach, surgeon, the whole team involved. That way, it helps to keep us honest. It helps us to make decisions about moving forward and maybe what are the main priorities for us to work on. But then also what does this timeline roughly look like. If I’ve got an athlete who is nine months post-op, but they’re only hitting 50%, 60% symmetry, that’s a problem. That’s going to let me know, guess what, you still might not be there for quite a minute. And we’re still going to be looking at like 12 to maybe even 14, 15, 16 months because of just where their current baseline is. This is something that we want to make sure that we have targets on. And this comes back to a podcast episode I did on knowing your numbers. I think it’s important to know your numbers and to be able to know what you’re aiming for. If you are an athlete who is in this position and you don’t know your numbers, find out where your numbers are. If your PT says, don’t worry about it, find a different PT, because you need to know these numbers and your PT should care that you know these numbers. Everyone of our athletes that we’re working with, they know where they’re at and so they need to know what they are working towards. Have a regular cadence of a minimum of four to six weeks in my opinion of testing. Outside of that initial injury or post out window, which is a little different where you can’t push it as hard. But once you’re in a place that’s safe and your knee is quiet, it can tolerate some higher level forces. And you’ve been working on knee extension at a lower level and then you’ve been building up to heavier and heavier. Then therefore, you do have somewhat of a green light to be able to start testing and that could be in that regular cadence, as long as it also makes sense within what your goals are and then also with the overall plan. 

To me, rehab and performance training constantly serves as an assessment for our athletes. Seeing how they move, how things feel, the numbers, etc., from the movement prep, the warmup, to the compound list to isolated movements, the positions athletes are in, the dynamic work, there are so many different things that we can look at working with athletes that it gives us such a good idea of where they are. And then anytime we actually do test if we have been working with the athlete, I have a good idea of where they’re going to be at. Honestly, this is how most PTs and coaches should be with their athletes. There can be a surprises here or there of like certain numbers they hit. But it’s super rare if you’ve been staying on track with testing and being able to keep up with watching your athlete and checking in with your athletes. 

To me, three months is too long in between and an opportunity cost because that can waste your time on things that might not be moving the needle or important. You don’t really know because you haven’t really tested or there’s a long time span in between. I’m also just not sure how you would guide your programming if you don’t test, to be completely honest. It feels like you would be shooting in the dark a little bit. It’s like, all right, I think I’m going to work on this. This is probably what the protocol says. This is the normal routine and what PT does. But there are goals you set and short-term, long-term, certain KPIs or criteria we’re aiming for. And this is something that’s going to be really important in terms of what we call exit criteria, which is where we need to make sure we can hit this certain threshold of a number and a certain movement in order to move forward. These build on top of each other, and the only way we’re going to know that is if we test. And if we don’t, then we don’t really know what it is that we’re at. And then therefore, it’s really hard for us to really dial in programming and be as individualized and custom for our athletes we work with. The thing that you hear a lot is: test don’t guess. This is so key, but we got to make sure we test the right stuff. We got to make sure that we structure it in a way that is strategic for our athletes. The other thing too, is that we got to make sure that we dial in the frequency that works best for our athletes based on what phases they’re in, the stages they’re in, to make sure we can continue to drive outcomes that are going to be really impacted by the program design that we give them. 

I hope that this was helpful in terms of the frequency, the structuring, some misnomers about some other tests that can be often used with ACL rehab. If you have any questions, you guys know where to find me. If you’re a clinician and coach, I hope this was helpful. If you’re an ACLer and you’re like, I don’t know what any of this is. I don’t feel like my PT is doing any of this stuff. Then ask them questions. This is something that we don’t do or we’ll get to it. It’s very vague and they don’t really have very specifics on it, then start to question that. Start to see, okay, is this the place I need to be for a long-term? I’m not saying it’s bad. It’s just something that if you are with it with ACL rehab at this point in current day, 2024, you should have testing a part of the repertoire. You should have that very regularly. You should know what your criteria are. You should know what you’re testing. These should all be very dialed in and being done with you in this process versus feeling very sporadic. You should know where this is throughout your entire ACL rehab process. 

If you do have any questions, reach out to me. Otherwise, I will catch you next time. This is your host, Ravi Patel, signing off.