Dr. Jason Lunden // #FitnessAthleteFriday // www.ptonice.com 

In today's episode of the PT on ICE Daily Show, Endurance Athlete Division Leader Jason Lunden discusses helping patients return to running following ACL reconstruction (ACLR). Jason describes healing & strength benchmarks to use to initiate running, strengthening needed to facilitate return to running, and biomechanical changes that need to be addressed to improve performance.

Take a listen to the episode or check out the full show notes on our blog at www.ptonice.com/blog

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EPISODE TRANSCRIPTION

JASON LUNDEN
Hey, good morning, everyone. Welcome to another edition of PT on ice daily show. My name is Jason London. I am the endurance or the endurance athlete division lead. And I am happy to be chatting with you all today. We'll be talking about return to run following ACL reconstruction. Sorry that I'm on a little late. I just wanted to avoid my dogs going crazy when my daughter was getting picked up. So for those of you who are patiently waiting since seven, thanks for your wait. So we're going to be talking about return to run following ACL reconstruction, covering, you know, why do we care? when that happens and why do we need to be thoughtful about that, what do we look for as our athletes are returning to run, and then how do we address it. So one, why do we care? Well, several different reasons. First and foremost, performance. We want to set our athletes up for success with when they're returning to run and being able to demonstrate good mechanics for performance, but also We do want to be thoughtful of that healing ACL graft and as it is going through the ligamentization phase, we want that to have basically been gone through that full phase before return to run just because of the stresses placed on the ACL with plyometrics, even though running itself in healthy adults should have very low stress on the ACL. And then third, probably the most important piece with really being cognizant of what's going on with their gait mechanics is a high rate of early onset osteoarthritis following ACL reconstruction. And with that, there's been studies looking that have shown that It really comes down to one of the risk factors is patients who under load the operative side seems to be one of the driving factors for early onset arthritis. So it's going to be something that you want to look for.

CHANGES IN MECHANICS FOLLOWING ACLR
So what do we look for in these patients who are returning to run following ACL reconstruction? Well, the main things that we see in the literature and then I would say I see in the clinic as well is, um, I'm jumping ahead here a little bit. But what we want to look for is those patients that are underloading the knee, so decreased knee flexion on the operative side in the sagittal plane at mid stance compared to the on operative side. So any difference greater than two degrees of knee flexion at mid stance is something that we need to address. That patient is underloading that knee. And then the second thing, particularly for patients following a hamstring autograft, semi-T, semi-membranosis autograft, is increased tibial external rotation during stance, which has been shown to be in the literature. Now, I jumped ahead there a little bit.

WHEN CAN WE RETURN TO RUNNING?
You know, when are we actually allowing these patients to return to run? Again, we want the graft to have gone through the ligamentization phase. So that is going to be at four months, anywhere between three and four months. But to be on the conservative side, you would want to wait till to the four month mark. And in addition to that, we don't want to just be timeline based because, you know, assuming that the graft has gone through the ligamentization phase is all done on you know, benchtop research. So we do want to have our objective criterion as well for when these patients are ready to return to run. And so we want, first and foremost, you know, full passive range of motion, minimal to no swelling, and normal walking gait. Those three things, in my mind, should almost always have been achieved by the six-week mark, so it gives you plenty of time before you're even thinking about returning to run. In addition to that, objectively we want them to have a certain level of strength. So we want 90% limb symmetry index, so 90% of what they can do on the non-operative side for hip strength, particularly hip abductor, adductor, and extension strength. And we want 80 to 85% LSI of knee strength, so quad and hamstring strength. Ideally testing all of these with, isometrically using a dynamometer. If not, you know, coming up with other ways with one rep maxes, planks, et cetera, to try to get a little bit of a better sense rather than just your hand doing that isometric hold and rating it a, you know, five out of five. In addition to 80-85% LSI with isometric strength testing for the knee, we want there to be some objective testing too. So we want the athletes to be able to perform single leg squat to 60 degrees with really good form without having to put their contralateral leg down and then do a two minute timed single leg squat max reps in two minutes and comparing that to the contralateral side and wanting that to be at 80 to 85% of what they can do on the non-operative limb. So this is, of course, going to take them some time to achieve. And so generally when that is going to happen is between the three and four month mark. So again, 90% hip strength, 80 to 85% knee strength, both isometrically and objectively.

INITIATING RETURN TO RUNNING
And then when they are returning to run, we're going to start with a walk jog program. where they're going to be jogging for a certain number of minutes and then having a walking interval with that. And gradually ramping up, depending on their experience, to where they are running continuously for 30 minutes. Once they've hit that, then you can have them do a threshold test. And basically, after they've had two successful bouts of running at 30 minutes without pain, having them on that third run of that week going to run as long as they can without pain during the run and for 24 hours after and that would set their threshold in terms of where they're going to be starting out at and then you're going to increase their running volume off of that.

LOADING TO FACILITATE RETURN TO RUNNING
I got a little bit ahead of myself earlier on but what we do want to look for is decreased knee flexion or underloading in mid stance on that operative side or excessive external rotation on that operative side as well of the tibia. And so how do we address that is mainly making sure that for the loading that one that they do have adequate quad strength to accept the load so really working on a lot of eccentric quad strengthening using the extension machine, leg press or or weighted wall sits, and then also doing focused loading patterns. So I really like having them do crouched carries with the knees flexed to approximately 60 degrees. I'm really teaching them to load through that knee that way, as well as doing some supported hopping with a monster band, a pull-up assist band, to really get them to load through that knee.

ADDRESSING GAIT MECHANICS
And as we know from a lot of the literature is, you know, strengthening alone is not going to carry over to the gait mechanics, unfortunately. And so we need to give them some cues while they're running to increase loading and knee flexion at mid stance. Probably the best cue to give them is to try to hit the ground hard when they're running. It's a nice external cue that seems to work better. Otherwise, other things you could try is telling them to try to sink into their stance more when they're running too. And, you know, having them do that in block training. So, you know, a lot of verbal feedback for them or auditory feedback based on how they're they're striking and titrating that over time. For the increased tibial external rotation that really again goes back to hamstring strength particularly medial hamstring strength since that's where the graft was taken for those hamstring autografts and in the study by absorted kick in 2017, they found that those athletes who had less than 85% hamstring strength compared to the contralateral side were more likely to have that tibial external rotation. So again, focusing back to that strengthening of the hamstring, but having to get that carry over for gait too. And what I found is I don't have really good external cue for them, but just having them thinking about when they're coming into flight phase is having them pick their foot up and internally rotating their foot to overcompensate initially, and then gradually that works itself out. So return to run for ACL reconstruction, you know, we're probably getting in the time right now where this has been happening for a lot of you for those athletes who tore their ACL in fall sports. Winter sports, we're probably not quite there yet unless they tore it in early season, but really be thoughtful about the timing of that. Again, thinking of wanting the graft to have gone through that ligamentization phase, so generally around four months, and generally they're not going to be ready until that point anyways if we look at our objective criteria, particularly of the 85% isometric strength of quadriceps and hamstring and being able to get 85% of what they can do on the control at all time with that two minute timed squat to 60 degrees. Again, this is important for performance. important for good outcomes following that ACL reconstruction and most importantly important for trying to decrease that rate of early onset arthritis at the knee following ACL reconstruction. So hope you gained a few pearls here. Working with ACL reconstruction patients is very rewarding and a lot of fun and don't just fall into the habit of When it's time to return a run, just sending them off with a walk jog program. Make sure you're looking at their gait mechanics and addressing that and thinking also about what is that athlete's history of running and what are their goals for running too.

SUMMARY
If you're looking to join us for any of the endurance athlete courses, we are just starting up the second cohort of online and unfortunately that is full for any of those that would want to join. So your next option there is May 7th, I believe. The first professional bike fit cert is coming up here in April, April 20th in Asheville. This is a little bit of a special one. as that the other lead faculty, Matt Keister, and myself will both be teaching that, so it should be a lot of fun. And we're really looking forward to hitting the trails around Asheville for some great biking. And then the first rehabilitation of the injured runner live course is going to be in June in Milwaukee. That one is filling fast, so if you're thinking or sitting on the fence on that, Make sure you sign up for that quickly. We do only have two live courses this year for Rehabilitation of the Injured Runner live, but we will be offering more next year as Megan Peach is moving back stateside and we'll be able to teach with that. I hope you all have a wonderful day. Get outside and do something fun with friends and family over the weekend, and we will catch you all later. Bye. Did you see him? I need to go get ready.

OUTRO
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