It’s important to have objective test data to safely progress patients and return them to sport after injuries like ACL reconstruction.
Isokinetic testing is still the gold standard. However, the machines are large and expensive, and they are used much less frequently.
We don’t even have an isokinetic machine at Champion.
Here’s what we do instead.
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#AskMikeReinold Episode 362: Do You Need Isokinetic Testing?
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Show Notes
• Evaluation and Treatment of the Knee Masterclass
Transcript
Student:
So we have a question from Chuck from Toronto. He asks, “I’ve been following you online for many years and have never seen you use an isokinetic machine at Champion. What do you use to test strength after surgeries like ACL reconstructions?”
Mike Reinold:
Awesome. Great question, Chuck. That’s a good observation too. That we’re never really doing that. Man, we used to do isokinetic testing when we had a huge, huge facility, in-house physical therapy with doctors in the same building, that sort of thing, and they were just doing such a high volume of ACLs and stuff. We used to churn those out and do a bunch of testing, and very helpful for return to sport. Locally in Boston, we do have some facilities that do testing for that, that sometimes we have our patients go to or the doctors send them to. I do know there are some people around the country, even in clinics like Champion, that’s cash-based type clinics, have purchased Isokinetic machines. I’ll say, from a business perspective, a couple things. One, super expensive. Two, huge floor space footprint thing, which is always the first conversation we have at Champion. And we have 11,000 square feet, and it’s still the first conversation we have with every single thing that comes to Champion. As you say, what’s our usage per square footage, and how is this going to impact the flow of the facility?
And those are really the two main drivers why we don’t have them. I’ll say, in my pro sport models that I’ve worked in too, we’ve also haven’t had them. So we’ve been in situations where we have them and we haven’t had them for forever. Clearly we don’t think we need them, otherwise we’d buy them. So that’s the real question for us… Okay, all right, what do we do if we’re not doing isokinetic testing? I know we feel good about it, but who wants to start and kind of go over some of our protocols for… You know, they mentioned ACL reconstruction, but really for anything like what we do… Who wants to jump in on this one? Kev, you want to start?
Kevin Coughlin:
Yeah, I’ll start. Yeah, at least for the ACL, we use inline dynamometer testing, and that’s worked really well. I think Dan might know the specific research study, knowing Dan, but I think it’s been validated with the isokinetic testing to be fairly reliable. And I would say, like you had said, Mike, there is a place locally that does isokinetic testing, and when we have patients come in that have had testing there, and we kind of compare the ratios to what we’re getting with our LSIs on the inline, it is fairly similar. So that’s always good to see, and reassuring. We tend to test in the 90-degree position for knee extension, so 90 degrees of knee flexion, and this is because it’s an easier way to calculate the torque to body weight ratio that we like to use for that quad test.
And then we also will test hamstrings at 90 degrees. And then I’ll test hamstrings as well at 60 degrees, usually. Just because oftentimes in that setup, patients don’t feel like they have a great pull of their hamstring from 90. But just to kind of get a comparison at different angles, I think that’s been helpful. And the inline dynamometry just seems so much better than handheld in that position. I can’t imagine doing that, and I know we’ve had some people referred to us that have done that in other places, and the numbers just seem crazy compared to what we get with the inline dynamometry. So it does seem to be fairly accurate, and it’s been good to use.
Mike Reinold:
Yeah, that was not a fun time where we were trying to figure out setups with the push-based dynamometry versus a pull-based, and everybody went through that. Pull wasn’t as common 10, 15 years ago. So these push-based systems, and you’re trying to finagle it against the leg of a table, and I think that’s where people give up a little bit. There’s even publications with push dynamometers that are positioned against a leg of a table and you’re trying to kick… And man, it’s so hard to get your body in the right position. It’s so hard to feel stable. It’s just so hard to keep the dynamometer in place. I think that’s where a lot of people gave up. So we started going more inline just as a profession, quite a bit, and even just some general strain gauges that you can get from Home Depot do a good job with inline.
So that’s pretty neat. They have some better devices now, that are actually built for dynamometry, that you can spend $1,000 or whatever for. We use the Vault Dynamo because it collects data, it puts it up into their cloud platform, and we can assess it over time. We like that. But heck, there’s no reason not to. Now, for this pull, inline-based stuff, you can use that and the Tindeq. And the Tindeq is like 100 bucks or 200 bucks, and you get a pretty good model for assessment right there, just for cheap. So there’s really no need of doing it. But in addition to that, I would say we’re starting to gravitate towards more.
So maybe I’ll throw this at Dan a little bit here too to get his thoughts, and this is something he’s been building out in his head, but we’re doing more than just strength testing anyway, and more than just a simple hop test. We’re using some other equipment now for both vertical, and now even horizontal for stuff. But Dan, you want to give a snapshot on maybe some of the other stuff we do in terms of just inline strength testing? But what else are we doing to document good strength and power progress in our people?
Dan Pope:
Yeah, I think so. I think the big thing that’s different now is the force plate. But before we go into that, I do think you can probably throw in rate of force development for the same handheld dynamometry tests. And I do think they’re a little tough to test, and looking at some studies, it looks like they kind of take a snapshot of that initial press, which is not necessarily standardized from study to study. And I’ve been messing around with it a lot. I think there are some practical issues with it, sometimes with the handheld dynamometers as well. Your queuing has to change a little bit too, but we are finding, with a lot of these individuals, their strength is coming back, but the rate of force development is lagging behind a little bit. And you can measure that with the handheld dynamometer, depending on what you have.
But what we use as well is going to be the force plate, which is pretty cool. And I think we’re still trying to build out the exact tests that we really like to use. But generally speaking, we’ll look at a variety of different types of jumps. So we’re looking at jumps that have a short ground contact time and a longer ground contact time. So, short ground contact time would be 200, 250 milliseconds or less. And a longer ground contact time would be above that. And essentially, we’re looking at a counter movement jump, and we’re looking at double leg as well as single leg. And then we’re looking at a shorter ground contact time. We’re looking at more hop testing. So, hop testing is, think about a pogo jump, just trying to jump as high and as fast as possible. We’re trying to minimize contact time on the ground, but also jump as high as you can.
So, obviously, you want to see symmetry between sides on a hop test. I think that’s going to be important. But it’s also really nice because you can gauge how fast, or if, someone is progressing, and kind of see where their deficits are. If someone has a harder time with the longer ground contact time testing, we can give them more longer ground contact time plyometrics. Or maybe they’re not progressing at all in those capacities, we just have to give them more. Or maybe it’s the short ground contact times.
And what I’ve seen too, and this extends beyond the ACL, but certain joints may regain certain qualities faster. I think one obvious one is like Achilles repair. And the Achilles repair, the hop test looks horrible for a long time. Whereas for post-op ACLs, it looks quite a bit more symmetrical earlier on. So we’re using a lot of that to drive our exercise selection throughout the rehab process, as opposed to just, let’s say, criteria-based progressions, which is obviously important. We’re trying to marry the two. So, when can we start running, when can we start jumping, when can we return to sport, and how do we alter the program with this data? It’s interesting. It’s kind of a fun time in rehab.
Mike Reinold:
Yeah, and I would just add with the force plates too, you can do an isometric mid-thigh pull, or you could do like a cable-resistant squat, which a lot of times we’re doing a belt squat thing with cable attachment there. There are some isometric strength testing that we do on the force plates too. The future is, something that we’ve been starting to build out a Champion now, is also resistance and strength and power metrics in the horizontal plane. So force plates are great, but they’re vertical. So that’s great, but horizontal plane… So we’re using a 1080 sprint, a nice device that can measure output going in a horizontal direction now too. So I think to answer your question, Chuck, and kind of get back to it, isokinetics are great. If you have it, gold standard, why not, right? You should do it. But I think as a whole, I’m very happy and I’m very satisfied with our palette of options that we have between inline dynamometry, force plate strength testing, force plate jump testing, and then horizontal testing. Now with the 1080.
I think we actually have a more 360 view of the person anyway in this fashion, than just relying on isokinetics. So again, do you need isokinetics? No, I don’t think so. And Kevin mentioned it: there’s some studies that show some reliability between the two devices. I think there’s more to it. So anyway, hope that helps, Chuck. Thanks for submitting a question. If you have something like that, head to mikereinold.com, click on that podcast link, and you could submit a question. And please, Apple Podcasts, Spotify, rate, review, subscribe. We’ll see you on the next episode. Thanks.
