Two Recent BFR & ACL Papers

In episode 65 Johnny makes his triumphant return after defeating Montezuma’s revenge to help the guys breakdown a couple recent publications on BFR and rehab after ACLr. Zac takes the lead on the first of the papers that had a bit of a clickbait title per the fellas assessment. The paper titled, “‘Real world’ clinical implementation of blood flow restriction therapy does not increase quadriceps strength after quadriceps tendon autograft ACL reconstruction” has a number of demographic problems the fellas discuss, and ultimately evaluated one of the least relevant outcome measures by their estimation. Kyle finishes up the breakdown with some alternate and far more accurate title suggestions for the paper. The second paper they discuss was a recent review paper on ACL and BFR. Ben takes the lead breaking down this paper where the fellas have a tough time sorting why some studies were excluded and why at least one was included. Long story short the evidence on BFR use in ACLr rehab is still very limited and a review focusing on most all aspects of that process should be read with a healthy level of skepticism. Find us at: June 26-27: https://convention.nata.org/ June 29-30: https://hockey.eliterehabconferences.com/ July 13-14: https://basketball.eliterehabconferences.com/ Medbridge ACL Series: https://www.medbridge.com/

https://owensrecoveryscience.com/

Transcript

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SPEAKER_02 0:11

I started not giving you the invite though. And then just feel like yeah, guys, I think you've done an invite into a battle.

SPEAKER_04 0:19

Is this what it's gonna be? All right, let's say that now. All right, hi. Welcome back to Orange Cover Science Podcast. I'm back, baby. Johnny Owens is back. I got so many tweets of like what the hell the last podcast was at. Um, text messages like, dude, this was garbage. Can you please come back on? So I'm not crazy. Actually, I got the opposite, man. I had some people like, dude, they don't even need you. Why are you why are you even on this? I heard Ben Ben talked more in that podcast than he's done in every podcast we've had.

SPEAKER_01 0:58

Yeah, we I want to operate time.

SPEAKER_03 1:02

Somebody had to fill in the comedic relief, you know. That was uh that spot wasn't occupied.

SPEAKER_04 1:08

Uh oh, geez. Well, yeah, dude. Well, I almost died, you know. I I had Monazuma's revenge. Um, I lost 12 pounds, and the day of our podcast, I had to go to the hospital and get fluids. Two bags of magnesium, which took five hours because I have to drip it so slow. So, anyways, um sorry I missed you, fellas. Um, you'll be happy to know I put the weight back on. Nice. All right, today we've got uh controversy, baby. Um, we've got a couple papers that have come out on ACL and BFR that I think there's been some Twitter kind of action on it. Um, and there's also been some texts that I've received, like, have you seen this type of thing? One of them that it's kind of almost like a clickbaity type of clickbait type of title, which catches your attention. And that's that's the trend nowadays is to do the sexy title on the paper. But um, we're gonna jump right into it. So the first one, I'm gonna let Z um break it down. He's already brought out his little stats machine and his calculator and has been looking at all the numbers and everything on this. So, Zach, without further ado, man, describe this paper, give us the title, and let's let's get into this bad boy.

SPEAKER_05 2:21

Um, so kind of starts out in um quotations, real world. Uh, and then clinical implement implementation of blood flow restriction therapy does not increase quadricep strength after a quad tendon autographed ACL reconstruction. Um, so uh from there, basically the the question that um these researchers wanted to ask was Does BFR result in increased quadricep strength at different postoperative strength assessments? And does BFR result in significant increases in quadricep strength over time compared to traditional rehabilitation protocols? The purpose um to evaluate the effect of a postoperative rehabilitation plan with the real-world clinical application of blood flow restriction therapy compared with standard rehabilitation without BFR following a quad tendon autograph ACL reconstruction, specifically examining quad quadricep strength parameters over time. Uh, they hypothesize the addition of blood flow restriction therapy would result in increased quadricep strength at postoperative strength measurement time points and a significant increase in quadricep strength over time between repeated strength measurement time points compared with standard rehabilitative uh protocols without blood flow restriction. Woof a lot.

SPEAKER_04 3:55

Yeah, I mean the when I heard real world at first in quotations, I thought it was a BFR study on the cast from Real World from MTV. It was like an M T V thing. Yeah. Who are the people on Real World? There was what's there were so many puck. Um it's been a long time.

SPEAKER_05 4:18

There was like 20-something seasons, Kyle. Come on, Kyle. Oh, there were? Oh, I don't know. Uh so that that's Kyle's more of a VH1 guy. He's real housewives on Bravo guy.

SPEAKER_02 4:32

Oh, definitely not.

SPEAKER_05 4:33

But uh, so so then um kind of getting into the nuts and bolts of this deal was um it was retrospective in design. And so what they did was they looked at um their inclusion criteria were individuals greater than the age of 14 who underwent an ACL reconstruction between 2016 and 2021. Um, they had to receive at least two quantitative um isometric strength measurements. Um, and so from there, there that included 45 individuals in the BFR group, um, and then they had 36 in the um traditional rehab group. Now um they tested three time points, um, and you'll see that there was there's a big drop off in the um in the traditional rehab group between two and three assessments. So again, the BFR group started with 45 individuals getting at least two. 32 of those individuals then had a total of three strength assessments. The traditional rehab group started with 36 um that received the two strength assessments, and then it cut in half, and only 18 went on and had a third measurement um uh performed. So uh exclusion criteria was an ACL reconstruction with a graph choice other than a quad tendon. Um, if they had either incomplete or inadequate post-operative strength measurements, um, different types of ACLs, double bundle, hamstring, patellar tendon, allograph, and such. Uh, if they also had a previous um ACL injury on that side or a contralateral ACL reconstruction, uh osteochondral defects, um, meniscus repairs, partial menasectomies, and then also if they had a lamure procedure or a lateral extraarticular tenodesis. Um, so if they had those done, they were not included in the analysis. Now, um, when you look at individuals who who were enrolled specifically in the BFR group, um it was it was interesting the wording and and how they phrased everything. So BFR therapy was used by some of the physical therapists as a standard modality um with all of their patients, um kind of in this post-operative ACL um rehab, while other physical therapists reserved the use of BFR um for patients who they thought may struggle with strength recovery. Um the BFR was started somewhere between two to six weeks post-operatively. So it kind of sets a stage, right? I mean, you're you're looking at this and you uh, and just so everyone's familiar too, this was a multi-centered trial um within the same hospital system, but they have a ton of different clinics. And so from there, um, numerous therapists, different clinics, different locations, some of which use it as a standard of care. Like, this is what I'm doing. When I get a post-op ACL, we're doing BFR. Others were like, well, you know what? What we're gonna do is we're gonna hold off. And I don't really think I need I have a need for BFR in an acute post-op situation. Um, and they'll then try somewhere in that like two to four or two to six week time period, be like, hey, this individual is struggling, they're not making the progress that I think they should. Then we'll start doing BFR. So you you you it you know, you might say that um some hard gainers were then moved into the BFR group and contributed that to the analysis. Um, and so from there, um it gets interesting too looking at um kind of yeah.

SPEAKER_02 8:43

What do you mean by uh hard gainers?

SPEAKER_05 8:47

So, like a like a hard gainer is gonna be someone who is gonna have difficulty putting muscle back on, whether that's muscle mass or muscle strength. Like they're just going to struggle. Okay.

SPEAKER_04 8:58

Uh so you're essentially saying you Kyle versus me. Yeah, exactly. So you're gonna be a hard gainer. Yeah, I'm a gainer.

SPEAKER_02 9:06

See, well, that I yeah, no, though that's important because I literally thought you meant the opposite. Like these people are really gaining muscle faster, they're gaining it hard, they're moving. So you're basically what you're saying is there's a real strong likelihood, which they which they did mention in their limitation. They mentioned this, yeah. There's a strong likelihood that they had a selection bias, and that the people that were getting added to the BFR group were people that were essentially kind of behind where they would expect them to be.

SPEAKER_05 9:35

They were not moving along, you know, and it's and it gets like they hooked it gets tricky teasing that out because I think without getting too far ahead, one of the limitations is you you um we don't have basically who who the numbers that were enrolled in BFR immediately, and then those who were in the delayed group or or like who moved over afterwards when they when the therapist thought they were struggling persons not really making prior. So we you you don't really know. Um, but when you look at the demographics, right? So every when you look at the mean age, pretty close, like 22 and a b uh 22 years old in BFR group, traditional rehab was 19. But when you look at the the age range, dude, it it runs the gamut, right? I mean, you have 17 to 45 year olds in a BFR group, and in your traditional rehab group, you're looking at 14 to 23. So, you know, much much younger um group. And then you take a look at gender, um uh 26 females were in the uh BFR group. Now that that basically is 57 um of that of the group were females, but then you take a look at traditional rehab, and only 13 um were females. And so now you and that's 37 percent. Um they reported it there there was no significant difference there. Um I I think like maybe it was very, very close uh on the the chi square that they ran. Um they didn't put the p-value in there, but um I would suspect that that difference is is somewhat close to reaching significance. Um I hate not to see in a p-value and just put in non-significant you would uh you know I I think if if you can easily run a chi-square in XL and you will see that that number is close to reaching significance. So, but and then I think then you you look at um time points of uh of assessment for the strength. Um test test point one in the BFR group was at 4.8 months, um, versus traditional rehab was at 5.6. Um, time point two was 7.5 months, uh traditional rehab was eight point six months, and then the final um time point from surgery to strength assessment in the BFR group was 11.1, and traditional rehab was 11.8 months. Um this gets interesting as well because you're you're looking at a four-week difference. Basically, there's a one-month difference between assessments, except for the final assessment.

SPEAKER_04 12:28

Um yeah, the BFR is behind in that one month. So it you know, think about your patient at 18 weeks versus 22 weeks. It's they're they're gonna be different.

SPEAKER_05 12:40

Yeah, that's it, you know. And and I and I think like at least for me, one of the the interval at which I assess strength is every four weeks. Um I mean it's it's it's it's enough time where you're going to get a strength difference. You you should have change and shrink in four weeks.

SPEAKER_04 12:57

When people ask us, you know, how long should I do my BFR or when we send up a trial, it's like, well, we need at least four to six weeks, you know. That's that's kind of the minimum, but you you you would hope at four weeks you're seeing some change. So yeah, that that was a big that's kind of a big problem, even though again, not significant. Um anyone in the rehab world knows a month difference in post-op ACLs is is pretty big deal.

SPEAKER_05 13:21

Yeah, I'm sure like when you when you run you know the the Man Whitney test, uh which is what they use for that, uh you know, you're looking at like literally one number difference. Of of course, like one number is not gonna make a statistical difference like literally going from like four to five is not gonna be statistically significant, but uh man, on the clinical side of things, that that's a that's a pretty significant um gap in time.

SPEAKER_03 13:48

Well, this is where the term real world kicks in. It does does seem very real world. And you know, Zach, I may be jumping ahead of you here, but something that for me makes it again very hard to look at these two groups and compare them is the BFR group, they reported some numbers on the number of sessions before the first measurement, in between the first and second, in between the second and third. And we don't have any of that information on the standard of care group on you know, did they train at the same frequency? Was it more frequent? Uh, you know, what does that what does that look like? Yeah. I mean, so and just a huge variance in uh sessions, you know, for the time point one, you've got uh 18 sessions on average for the BFR group, but that's plus or minus 15 and a half hour. And then for the second measurement, between one and two, you've got eight sessions or plus or minus six and a half. So you might have one and a half sessions, whatever that is, or you know, you might have uh 14 sessions. And that makes uh you know, to me, a huge difference in what that uh that change is gonna be between measurement two and one and two.

SPEAKER_05 14:57

So yeah, it it uh yeah, the the the wide um kind of distribution is is is another you know challenge. Um but then um you know from there, so obviously our independent variables is gonna be the type of rehab, BFR or traditional rehab, dependent variable or variables was isometric strength in a biodex, and then um uh limb symmetry index as well. Uh and so uh you know, just uh challenges with limb symmetry index. Uh if uh I ideally you you want to know what a what the strength was going into the surgery.

SPEAKER_04 15:43

Um so explain LSI for some people that might not know it.

SPEAKER_05 15:47

Yeah, so what a limb symmetry index is is you're literally just looking at um the the difference between your involved and uninvolved side. Basically, there's two different formulas that you can derive that. Very simple, just divide them out, and you can get a limb symmetry index that way.

SPEAKER_02 16:07

Uh and kind of the take a peak peak torque before surgery on the uninvolved side, yeah. Right, and then you're gonna compare your peak torque on your involved side postoperatively to the pre-op uninvolved peak torque.

SPEAKER_05 16:26

And and so when you get your peak torque measurement, you divide the the um bad leg by the good leg, and it's gonna give you a percentage, it's gonna tell you how close the bad leg is to the good leg or the involved side to the uninvolved side, and then you like I people historically would track that. Um, and one of the one of the common cutoffs is you want um a limb symmetry index at the end of rehab at 90%. So you want a 10, like no more than a 10% difference in strength between your involved and uninvolved side. Um I I think there's limitation to the limb symmetry index, and that's why people have moved away from that. Um, and they look north now at peak torque to body weight ratios as kind of where we want to be. Now, a limb symmetry index is is good, but you need a normative value to compare that to because you don't know. I mean, you could have um uh a limb symmetry index of 0.95, but your peak torques are very the person's just very weak altogether. Um, but there's symmetrical other legs weak, yeah. And so I mean, like the the goal is they need to get stronger just all together.

SPEAKER_04 17:45

Um, so um without without the data of the uninvolved limb, LSI is really hard to interpret because it LSI could be improving, but their other legs get weaker, and that's what happened in their last two time points. The non-BFR group got weaker, and their LSI didn't change really. So that means the other leg got weaker as well.

SPEAKER_05 18:09

Yeah, yeah, that that's that's exactly it. Or, um, you know, a side note is there's a bit of a debate, I think, with people as to how hard you should train the good leg because you don't want the good leg to get really strong. I I I'm of the camp of I want the good leg to be as strong as possible. So we always have to leave out a debate.

SPEAKER_02 18:32

I don't know, honestly. Like, I is there a too strong? I would leave that. I'd be like, no, we're training everything as hard as we can.

SPEAKER_05 18:39

Let's yeah, uh, you because you need the good leg to be the reference standard, but then what happens is those people who don't really train the good leg because they don't want it to get too far ahead. When they do start training the good leg, it takes off, and now your limb symmetry index appeared to be close at one point.

SPEAKER_02 18:58

I don't think we gotta worry too hard about those people because I guarantee you they're using like bosu balls and shit when they're rehabbing too. So well, right, you know, like I mean, anyways, back to back to the back to the deal. They got some of those those little egg egg weight shaker Morocca things that shake weights, shake weights, yeah. No, but that's not what the guy calls them, you know, the wet guy.

SPEAKER_03 19:23

Anyway, I know what you mean.

SPEAKER_05 19:24

Um oh you oh, you're talking about gate, yeah, yeah. The wet guy. The wet weapons guy. Yeah, the pulsers. Yeah, there you go.

SPEAKER_02 19:34

Oh, the pulsers, okay. Yeah, all right.

SPEAKER_05 19:36

All right. Uh so now uh from there, moving into the results. So uh the first assessment, um, BFR um MVIC was at 95.6 foot pounds. Um, their traditional rehab group was at 111 uh.2 foot pounds. Uh that that there was a significant difference there between groups at the first time point. We had a limb symmetry index of 68% in the BFR group and an M or a uh limb symmetry index of 78% in a traditional rehab group. That did not reach significance, so there was no significant difference in limb symmetry index between um groups at the first assessment. Now you move into the second assessment. Um, and this was roughly around like eight, nine visits um later.

SPEAKER_02 20:32

And so um I would say if I could interrupt Zach, uh just back to the point we made earlier, the difference between time points here is a month, yeah, and and it shows like hey, there's a significant difference here between these people's peak torque at this time point, you know, just to kind of just to kind of support a month later breaking, and we already know they probably took weaker people, which they said they did in the BFR group, and so this first time point, you know, it's kind of all over the place.

SPEAKER_05 21:05

Yeah. And now, now, so we're at we we moved to uh time point two. BFR group has a peak torque of 118.2 foot pounds. Um, that that was a change compared to the first um assessment point of 22.2 percent. Um, traditional rehab group had a peak torque of 134.3 with a 24% change.

SPEAKER_04 21:35

Um, so those no, I had to look at that again, Zach. That's not the percent change. That's just the difference. Yeah, yeah.

SPEAKER_05 21:43

You're you're you're right.

SPEAKER_04 21:44

That threw me off because I I did percent change and I was like, this does not make sense. These these numbers don't you're you're right.

SPEAKER_05 21:49

I I stand correct. It it is that is the absolute change in peak torque. So um basically it was it went from 95.6 to 118.2. It was A 22.2 foot pound change. And then the uh MVIC group went from 111.2 to 134.3 for a 24.1 foot pound um change.

unknown 22:14

That's the same thing.

SPEAKER_04 22:19

In that first go run.

SPEAKER_05 22:20

And so and that that did not reach significance. Now um looking at limb symmetry indexes at assessment two, um, it was 81%.

SPEAKER_02 22:34

Hang on one second. When we say, because I this is kept confusing me when I'm looking at this. When we say that's not significant, what we're saying is there is no significant difference between your BFR group and your non-BFR group. What we're not saying is it was not it was not a significant difference between biodex one and biodex two. They did not they did not report that information, they didn't tell us if that change is significant. We would assume it is a 20-something percent change. And generally speaking, a 10% change when he's talking to force output is significant, but they did not report whether or not the change from test one to test two within the group was a significant change.

SPEAKER_04 23:19

You've right, it was between groups, that's it.

SPEAKER_05 23:22

And you you would have thought that they would have you would run that. Yeah, yeah.

SPEAKER_04 23:28

Because the first to third, we'll get into that. It was a big difference in the BFR group. Right.

unknown 23:33

Right.

SPEAKER_04 23:34

It's almost 50%.

SPEAKER_05 23:36

And then you you look at a limb symmetry index at assessment two, the BFR group is now at 81%. Um the traditional rehab group was at 90%. Um with a change of it was a 12% um change out of the uh 12%, 12, 12 foot pounds. No, no, no. We're on limit symmetry index now. On assessment.

SPEAKER_04 24:03

It's the same thing. They just added the numbers. They just it was actually a 19% change and a 15% change. So they did the same thing in the LSI. Yeah. I thought it was a percent change.

SPEAKER_02 24:23

Okay.

SPEAKER_04 24:25

No, they just did 81 minus 68.

SPEAKER_02 24:28

Also, this problem is they didn't give us values here. So Zach keeps saying foot pounds just because he knows that's what peak torques reported in, but it's not actually shown.

SPEAKER_05 24:36

Yeah, the the peak torque was never it, they never said whether they use Newton meters or foot pounds.

SPEAKER_01 24:42

Yeah.

SPEAKER_05 24:43

I'm I'm assuming it's foot pounds. Right. Um, just based on your knowledge.

SPEAKER_04 24:48

Yeah, so Zach, they just subtracted the it's the absolute value. So between LSI of one and LSI of two, they just subtracted those numbers. You got 12. The percent change in the BFR group was actually 19.

unknown 25:03

Okay.

SPEAKER_04 25:04

This could get kind of complicated for people. You need graphs or something on this.

SPEAKER_05 25:07

And then um, and then the the the change was um 12 in the uh for the traditional rehab group. So yeah, they went from 78% limb symmetry index to 90%. And then the peak torque values, oh but that did reach significance between groups, um, which was interesting because the assessment one, which was pretty much the same difference, 10% versus 9%, yeah. Didn't reach significance, but then at assessment by a lot too, 0.02. Yeah.

SPEAKER_02 25:52

You know, that's again puzzling how that first one right.

SPEAKER_05 25:57

You didn't reach significance there, but you did an assessment two, and then when you look at the standard deviations, um extremely wide at assessment two, and um for for the traditional rehab group, and um it was much more narrow within that BFR group uh on on the limb symmetry index. Um moving to assessment um three for peak torque, the BFR group had 138.5 foot pounds um compared to 130.7 for the traditional loading group. No significant difference um between groups there. Um limb symmetry index at assessment three was 87% for the uh BFR group and then 91% for the um uh traditional loading group. This is ultimately, I think we talked about uh towards the very beginning and whatnot. One of the challenges with interpreting all this is when you look at their tables, um, so for uh their peak torque um was at in table two, uh assessment two, 134.3, and then assessment three was at 130.7. So they actually, according to this table, got weaker slightly um for the traditional loading group. Uh and but then when you go down to table three, which is just below that, and you look at the change in peak torque between biodex assessment two and three, they report that there was an 8.9 foot-pound increase. Um I I don't know where that that number comes from.

SPEAKER_04 27:54

Yeah, I I was trying to see, does that work through the standard deviation? That that really threw me off as well. Is that number just a T.

SPEAKER_05 28:04

All the all the other numbers pretty much like somewhat checkout? Like if you just do the uh subtraction, the difference between assessments, they they're they're pretty darn close to what's reported, but that's like a um that's gonna be roughly a 12 foot pound difference. Um, when you basically you're saying they gained about nine foot pounds when they actually lost over three foot pounds.

SPEAKER_04 28:32

So makes no sense on that one. So I think I like to just think about percent change, even though that's kind of sometimes a no-no when you're doing the the actual research, but it's easier to digest for me. The BFR group, the first test, they tested them a month earlier than they did the standard of care group, right? So we know that's probably a problem. The BFR group between test one and two got 24% stronger, and the standard care group got 21%. Between tests two and three, the BFR group got 17% stronger, but the standard care group got three percent weaker. But the big dog I think you would look at is okay, well, what was between test one and test three? Um what was the percent change? The percent change for BFR was 45% increase, and it was 18% for the standard of care group. Standard care group started stronger and only improved 18% over that time, where the BFR group increased 45%. Now, again, it's kind of fudged numbers because these time points aren't the same. Yeah, but it still kind of helps when I look at that. And then if you look at the LSI, the between one and two, the BFR group got 19% stronger versus 15% of the non-BFR. Between two and three, the BFR group got seven percent stronger. The non-BFR had no change, basically. And between that first test and the third test, if you look at limb symmetry index, the BFR group improved 28% compared to 17%. And again, LSI is kind of a we don't know because we don't know if the other leg's getting stronger. I mean, we have BFR studies that show this crossover effect in the lower extremity. So it could be that that leg was getting stronger too, and that makes the BFR gains even more impressive because they're chasing a stronger leg. And obviously, the leg got weaker in the standard of care group, the uninvolved leg got weaker because the involved leg got weaker between tests two and three, and the limb symmetry index didn't change. So that means the other leg would have had to have got weaker. So they weren't doing this like comparing it to a pre-op uninvolved test.

SPEAKER_02 30:48

They were, they must have been checking time points bilateral at the time point, which is I think the other thing we do the other thing we do kind of have to remember, especially on the uninvolved, excuse me, not in the control group or the no bfr group, was they lost subs subjects to presumably you would think that yeah, they lost the subjects that were doing better. Yeah, because they just didn't they just didn't come back. So I you know that might be creating a little bit of noise there for us too, which is well, yeah, that's that's in making that group not look good.

SPEAKER_05 31:25

Yeah, I I thought that the um basically again, like with the standard being like if you're gonna base rehab criteria off a limb symmetry index, you get to 90%, and then you basically either you know, depending on who you are or what type of individual you are, go work with a strength coach, or you're good, you know, go do whatever. Um that's what I thought with the basically they lost half their sample um after the second kind of follow-up.

unknown 31:58

Yeah.

SPEAKER_03 31:59

Well, and as we talked about at the beginning, we know the BFR group was at least somewhat heavy with people that were struggling with restoring their strength.

SPEAKER_04 32:09

Yeah, struggling older, more females, significantly more, it sounds like from Zach's test. Um yeah, and they did at least as well. They had their time points measured early, yeah. Um, yeah. So I think our point was because I can already see the next orthopedia conference I speak at. Guys coming up to me, like, hey Johnny, did you see the the real world paper? You know, it doesn't work in the real world type of thing. Um, you know, and and they put that in their in their intro, like all these other trials were in controlled clinic, controlled lab environments. It's like, well, no, they're not. You know, that's where the testing's done, but they're doing the studies in in the clinic. It's it's a it is a controlled standardized planet care and controlled time points, but it's not like it's all done in Jeremy Linicky's lab type of thing.

SPEAKER_03 33:08

Yeah. Well, and they lost me when they said it was real world BFR, but then they said they did or they targeted 30, 15, 15, 15 with 80 occlusion at 30 to 40 percent of a one rep max as their BFR training. And uh that is something that does not happen in the real world unless we're not very good at assessing rep maxes. Uh, because uh if anyone's ever actually done this at 30 to 40 rep max, 80 occlusion and 75 reps don't don't happen ever.

SPEAKER_04 33:41

I think we all we should from now on say we tried to do 80 limb occlusion, but some of the patients couldn't handle it. Yeah, I mean, in our giant femur trial that just finished, I mean we had to document every time we changed the pressure. Um, they have all that data to spin a second paper of like how many people actually were able to do it at these at these different pressures or at that pressure.

SPEAKER_02 34:05

Did y'all did y'all pay attention at all to how they ran their power analysis? And did that red flag you at all? Like, I don't I don't really understand this. It says an a priori power analysis was conducted utilizing data from a previous study comparing knee extension strength in patients undergoing BFR therapy versus those that did not receive BFR. Yeah, they just use they use loops. The reference they gave, the reference they gave. Oh no, it's it's not, it's ANOVA. And it's not even published. It's that paper's not even out. Um, so I don't know. And and and and if you notice, like the the control group had to be 18 patients, which is exactly what it is, you know, in that third time point. I mean, that's their that's their end. They hit that on the number. Um, so you just kind of wonder, like, man, I mean, I think well, Zach, you ran some of these numbers. It's like if there was literally like one more person in that control group or the BFR group doing good or bad, they reached significance.

SPEAKER_05 35:19

Um, yeah, the the the big one was was the the demographics. Um and and and that's the thing, you know, and I mean it's it this is one of the challenges. Like, what is a what's a good peak torque? Like, what what what does a good peak torque? I mean, that's like a bench press. What what's a good bench press number? What's a good squat one RM? I mean, with without having um a literally uh being able to put this into perspective, peak torque doesn't tell us much. I mean, unless you look at an individual that you're testing, and then you can go, oh, this is it, this is the improvement we got in your strength numbers. But again, like you can just take a look at like you take a 180-pound guy, yeah. You you you you take a 180-pound guy and 120 um pound female, or a 120-pound guy, it doesn't even really matter. It's it's body weight, right? And and so you know the goal with ACL rehab, or the goal with quad strength, I'll just say, is you want your strength to be equal to your uh body weight. You're you're not gonna have a 120-pound individual generating 180 pounds of force out of their quad.

SPEAKER_02 36:41

I was gonna say, let's be a little more specific. Should be equal to your body weight. So if you're a 180-pound guy, you should be able to kick isometrically at 180 foot pounds of 20.

SPEAKER_05 37:01

And and that, and that pretty much always it's gonna ballpark to three newton meters per kilogram. There's there's good data uh across the lifespan on that. And and so that that's the big challenge, you know, when when you only have one group has 37 percent of of their participants uh as one gender, uh, and then the other one, you know, 57%. And so uh and I and again, you know, you you take that aspect of it, and then you say, um, we put the the hard gainers or the people that were struggling to increase strength into one group. I mean, it's yeah, I wish I could design studies like that. That's why retrospective that would be like, you know, my real world example is like, you know, it's I'm gonna put the weak people that aren't making progress on someone else's schedule, and I'm just gonna let them deal with those results, and I'm just gonna pad my own uh results.

SPEAKER_04 38:04

Yeah, I mean well, I think we we broke down our thoughts on this. I think we hit the key takeaways. Don't you guys feel good about it? Anything we need to add?

SPEAKER_02 38:17

I bet they got Eddie Chang.

SPEAKER_04 38:20

What's that? I bet they got Eddie Chang's Eddie's presented that paper, and he I think he won an award for it at AOSSM. So I bet they just got his data um from his present when when he was there.

SPEAKER_02 38:31

Yeah, yeah. That was I was just like, because I looked it up, I was searching for it everywhere, trying to find like where did they get this from? Yeah, it's just the OSSM. I I made up some alternate titles for this study because y'all know how I get triggered with titles. So this will be but my first one, honestly, my first one is my favorite because they legitimately could have said this real-world clinical implementation of BFR therapy increases quad strength after quad tendon autographed ACL reconstruction. They they legitimately could have said the exact opposite, and that would have been truthful as well. Um I I also wrote this because they so they I don't know if y'all caught this, but in their uh introduction, they were talking about review papers and they referenced, they said, hang on, let me put it up, let me let me read it, I'll read it verbatim because I don't want to screw it up. Um while rehab protocol, no, that's not it. Currently, limited studies of small sample size, heterogeneous strength outcome measurements have been unable to draw firm conclusions on post-operative strength outcomes undergoing BFR therapy. We would all agree with that, I think. Um, but then they also said within that same as part of the post-op rehab protocol following quad tendon autographed ACLR. There aren't any there aren't any studies published with quad tendon ACLR. Eddie Cheng's group had six subjects because I looked at I went to Clint trials, they had like six subjects that were quad tendon.

SPEAKER_04 40:08

Our DOD trial is only quad tendon. Only quad tendon. Man, how's going up, Johnny? I was bringing that.

SPEAKER_02 40:15

I was like, I've been like, hey Johnny, know anybody doing a quad tendon trial?

SPEAKER_04 40:19

Um so I thought thunder because our thing was like nobody quad tendon.

SPEAKER_02 40:24

They did it because you can use this title. This is the title you can use now, Johnny. The first report of BFR therapy used in the rehab of ACLR via quad tendon autograft. And then I put a retrospective review, but that that was me recycling that. But you can you can steal that because they didn't. Um, I I I thought this could have been an appropriate title. Timing of force testing may influence findings in the early stages of rehab following ACLR via quad tendon autograft. Um I I therapists favor utilizing BFR over standard rehab when managing ACLR via quad tendon. I I mean that would have been fair because they had more subjects substantially in their BFR group. Heterogeneous protocols and samples once again demonstrate the difficulty of rehab trials, could have been another possible title. And then lastly, absolute force measurements and LSIs are not sensitive enough to differentiate the effectiveness of two different rehab protocols following ACLR. I like it. All great titles that would have applied perfectly, and we didn't, and we didn't have to, you know, use I don't know, maybe whatever clickbait title the journal wanted to use.

SPEAKER_04 41:43

I don't know how that if you want to uh write a letter to the editor and suggest new titles, I'll let you do it. Although I think you might have a problem with who the editor is. He's a great person, these are great people.

SPEAKER_03 42:00

Well, I mean, Kyle, we we need to get you uh some more, you know, muscle mag or or meathead terminology to work in there based on the fact that you're asking about hard gainers. Uh we I don't know.

SPEAKER_05 42:14

That's standard terminology. That's that's Jim Bro talk.

SPEAKER_04 42:17

Yeah, we just uh I think Joe Weeder invented it. Uh sorry, Ben, let up roll into this uh our second paper, man.

SPEAKER_03 42:28

Yeah, this uh so we've we've got this review paper, systematic review by Columbo et al. Uh title for this one is the comparison of blood flow restriction interventions to standard rehab after ACL injury. And I'm assuming they titled it after ACL injury as opposed to reconstruction based on the studies that were included. Um this is coming from a group over in the UK, and they were mainly looking at structuring this to examine the effectiveness of BFR versus similar rehab without BFR in patients undergoing ACL reconstruction. So they were primarily looking to assess knee extensor and flexor strength. Um, it also had to have some imaging that was either MRI or ultrasound included. Um, and then they also looked at a tertiary uh knee-specific patient-reported outcome measures. So um this is gonna come to as a shock to everyone here that um there were not that many studies that ended up meeting their inclusion criteria for all these things. Um the imaging requirements may have excluded a few. Um and so there's five studies that met the inclusion criteria, which uh, of course, makes it hard to create any real statistical power and and generalize the results. Um overall, you Got a 130 total participants that were included in this systematic review. 78 of those fit into the BFR. 52 of those would be either sham or control numbers. And we've got two prehab studies, which is again why I'm assuming we've got ACL injury in the title as opposed to just ACL reconstruction. Those were from Zargi and Kaysen's lab. And then you've got three rehab studies that ended up meeting the inclusion criteria. So overall, you know, the the the big findings that they came up with were that the results are unclear as to whether or not BFR can consistently um create increases in knee extensor and flexor strength after ACL reconstruction. They did say BFR may improve the you know knee-specific functional outcomes and patient reported outcome scores, but again, not enough there to say that that's uh consistent. Um and it it's I think uh really what we kind of all expected going into this as far as uh you know, we look at the studies that met inclusion criteria, and uh overall there's not going to be enough there to say we have this clear-cut answer that VFR is the you know best thing post ACL reconstruction compared to the uh you know control or standard of care in these studies that they use. I mean, even in you know, I think uh my bias is uh the Hughes study for leg press after ACL reconstruction is probably the best one of the bunch. And they compared BFR with low load to lifting heavy after an ACL reconstruction and showed that uh BFR was just as good as lifting heavy for making you better at leg press and for making your thigh bigger. And so that's again not not a huge shock that BFR didn't outperform lifting heavy. You know, they did have some improvements in pain, they had some improvements in functional outcome, you know, had some improvements in swelling and faster return range of motion, and it's some little things that seem to kind of say. But those aren't those aren't little. Well, I mean, just as far as like what would create statistical changes in a in a review. Um, yeah.

SPEAKER_04 46:34

And but I think they made it out that like Luke's paper was the winner, pretty much, it sounded like um when they're like looking at this. But yeah, BFR, the low load versus lift and heavy, they both there was no difference between the groups. Great. BFR is pretty equal to lift and heavy, but to have less pain, less swelling, better range of motion, improved functional, improved um self-reported in the BFR group, that's that's kind of the heavy hitters from a clinical side. So I I I I like that.

SPEAKER_02 47:07

And I think that I mean, we're again we're only talking one exercise there, right? So it was like that, yeah, like one exercise made a difference. So I think you know, there's a couple different ways to look at that. Man, all right, what could we get if we included a number of other BFR exercises in just one, but also like just one heavy-loaded exercise created that big of a difference, right? And the irritability of a knee, and that that's that's pretty significant, right? Um statistically, and just from you know the perspective of rehab.

SPEAKER_03 47:40

Right. Well, and then looking at the other studies included here, you know, you've got the two rehab ACL studies from Sargi and Kaysen. Um, so same lab, and one is five exercise sessions in the eight sessions, yeah. In the eight days leading up to an ACL reconstruction, and you only have one exercise being performed there, too. You've got a knee extension to failure with BFR or no BFR, and they only focus in this review at the 12-week time point, you know, which is their last time point. They're looking at you know, muscular endurance with a sustained isometric and blood flow of the quad. And there was no statistical difference between groups there, but the one-month time point, there's a very significant difference between groups. And so, you know, again, it it's maybe there's some picking and choosing of what you know is meaningful uh there, but also it's it's one exercise for five sessions, right?

SPEAKER_04 48:39

And you know, seems like then when you read when you read that paper, you know, you get the kind of spirit, yeah. Yeah, but also the spirit of what they were looking at, they were like, could BFR increase your your blood flow, your capillarization and maintain it post-surgery? Because post-surgery, when you have a reperfusion of the of the tourniquet, you have damage to the vascular beds. And that's you know, some people think that's what really wipes out quad endurance. And so only five sessions, they increased the capillarization by 50% at week four versus the the sham group, it was down 32%. And then the um the quad endurance, I forgot what the numbers were.

SPEAKER_03 49:22

It was uh like a 30%, 30% difference. Yeah, yeah, yeah.

SPEAKER_04 49:27

Drop in the control group, the control group control and the control group didn't lose it at all.

SPEAKER_03 49:31

Right, yeah.

SPEAKER_04 49:32

I mean, that's I it's almost like, dude, if you could get in for five sessions, that first month might be money for your patients because quad endurance is like one of the big issues of where you have instability and and all the things you're nervous about in that first month, that quad being fatigued and something happens on the stair or something. So the spirit of the study, and again, prehab versus post-op is probably going to be so different. I mean, if you look at the system review, two prehab studies, one did five sessions, one did one did three weeks or nine sessions, and then you got one post-reconstruction, which isn't even a BFR study, it's an IPC study, you know, for what eight sessions or something like that for two weeks. Like two weeks. And then you've got the ODA, which so many home-based protocol with here's your cuff, even though they didn't tell us what it was. Thanks for the thumbs up, Ben.

SPEAKER_03 50:24

And uh do anything.

SPEAKER_04 50:26

But then you got but then you got Luke's, which is probably the best one out of the out of all of them. So, I mean, it's just so much heterogeneity between these studies. I don't know how we could get anything from a review on it.

SPEAKER_03 50:37

Yep.

SPEAKER_04 50:41

Yes. So and I think the the um losing my train of thought on the uh what the hell was I about to say, man? Someone take over. I'll remember it. We'll edit all this out.

SPEAKER_03 50:57

Not really. I don't want to stay on your thunder, man. Rely on YouTube, right? No, you you're good, man. I mean, I think it for me, it was just looking at this review there's just not great studies that to pull information from. You know, the the fact that the Iverson and Ota studies met inclusion criteria, and some of the papers that I think we would all consider better rehab papers didn't meet the inclusion criteria because they didn't do MRI or ultrasound as part of the study. You know, Ota, you've got uh a pressure reported, but no cuff width reported in a home study where the exercises are not really loaded very well and not progressed well. And, you know, shockingly, there's no huge differences to be found that are making this review look more meaningful. And then the Iverson paper, you take a cuff that we're all familiar with and you jerry-rig it to put a hand pump on it instead of letting a computer you know pressurize it like it's intended to be. And like you said, you just have basically IPC, you have intermittent inflations at a pressure that actually is something we don't actually know the pressure because it's not well, you know. They generate a cuff, yeah. It's it's not being regulated the way it's intended to be. Um, and you know, again, shockingly, that's not going to create the results that you would uh hope to create. Plus, it's the first two weeks and it wasn't really you know something where they did meaningful exercise along with it. Um so it's uh you know, it's good to break these things down because I think it's it's good to draw attention to the fact that you know we're making statements based off of uh core information, which is not uh you know uh unexplored territory with within the research world. But um, you know, somebody could look at this and say, oh look, you know, BFR is not that great. The review shows us that. So yeah.

SPEAKER_02 52:54

You know, I'm just thinking that that the Zargi paper they didn't do imaging. They that's the that's the five days pre they measured endurance and microvascularity.

SPEAKER_03 53:10

Like they didn't well that's what we focused on. Did they do imaging? No, because they didn't did they use ultrasound to look at the blood flow side of things?

SPEAKER_02 53:19

Maybe that's what they did.

SPEAKER_03 53:21

No, they used nears. Is what I thought.

SPEAKER_02 53:25

Yeah, yeah, because uh like that was the whole thing with that paper for me, because they were trying to show if they could preserve muscle mass, but they didn't actually measure muscle mass. You know, they at least they didn't report it, they had previously shown that it mattered, like endurance mattered, and then they had this hypothesis as to why, which I thought was great, but but then they just didn't go that extra step and measure muscle mass.

SPEAKER_03 53:52

Well, I know their other study did because they reported the tree in the cross-sectional area, right?

SPEAKER_05 53:57

It had to, yeah, yeah, it had to, they they didn't they didn't do any um imaging.

SPEAKER_02 54:03

So I don't understand why that paper got included. So like Lambert got dropped and Connecticut children got dropped.

SPEAKER_05 54:11

I think I think Connecticut also got got dropped because they had Peds in there, um, and that was part of that this systematic review, specifically, I believe, part of the inclusion criteria. There was an age.

SPEAKER_04 54:25

Um where I think they said um one of the things that needs to be looked at is studies with people under 18.

SPEAKER_05 54:35

They couldn't find any 18 to 65 is the 18 to 65 was their deal, and Connecticut Children's had kids under 18.

SPEAKER_03 54:43

Let's just hope that they submitted this before that study was published. Yeah, it's possible. You know, we we do know how long it takes these things to get through reviews sometimes, so it's possible, it's possible, but yeah.

SPEAKER_04 54:57

Well, the Zarging I have an imaging, if that's true.

SPEAKER_05 55:00

Yeah, that's a major like I just pulled, I just pulled it up. And they chose the five session prehab one to confirm, and when you do a search for imaging, there's only one thing that pops up and it's in the references.

SPEAKER_03 55:15

Well, and the other thing is they're looking at nothing, there's nothing for ultrasound.

SPEAKER_05 55:20

Like if you do a a you know, fine, control fine or control F, whatever, uh there ultrasound, nothing comes up.

SPEAKER_03 55:28

Well, it also states that they were looking at you know they're looking at the effectiveness of BFR versus similar in patients undergoing ACL reconstruction, and that other prehab study, the three times a week for three weeks, didn't look at anything after reconstruction. No, it was only prehab, and it was only the time point before surgery. So the fact that that is included in what they're looking at here does not exactly match at all either. That's all over the place. So goodness. So they could have just done a review on on Luke's study and uh said, here's our review on BFR post-aclr.

SPEAKER_04 56:08

Um so well, good stuff. I hope that gives people a little bit of ammunition. If if someone comes at them with these papers and says, why should I do BFR because of this or that? At least you you have a deeper breakdown and kind of our thoughts of why. I I would I would go with the totality of the literature and not a single paper or a systematic review.

SPEAKER_05 56:35

Yeah, yeah. I mean, it's it seems to be good enough for Frank Noyes to uh change his practice in Cincinnati.

SPEAKER_04 56:45

So to only send BF patients out for BFR post surgery, you better be doing BFR.

SPEAKER_02 56:57

All right, gotta be doing it.

SPEAKER_04 56:58

Anything else, fellas?

SPEAKER_02 57:00

Not on this, but you know, hey, we should kind of tease a little bit. So we are now offering ultrasound, uh, introduction to ultrasound courses. Speaking of imaging, yeah. Speaking of imaging, so if you want to just learn how to do this and then do a study and get appropriately included into this review the next time they do it, um we can we can help you get there. Um, we're you check the website to find out where those are gonna be. Um, we're also actively coordinating sites. So if you want to host, send uh Ben Weatherford an email at Ben at Owens Recovery Sites.com.

SPEAKER_03 57:39

I would complain, Kyle, but um basically all all roads lead to my email.

SPEAKER_02 57:44

Um info goes there, big goes, you know, send it to the website goes there, it's it's all going to be he gets the majority of the no dude.

SPEAKER_04 57:52

You can send it to my email. It's been at Owens.

SPEAKER_03 57:57

Yeah, I've got your local rep. His his phone number is uh yeah.

SPEAKER_04 58:02

Uh no, but we're excited about it. We have Stephen Ramsey who's a stud in the ultrasound world. Um, and not only is it to understand how to measure changes in muscle and look at muscle architecture so you can show objectively did they did they make positive changes or going south, also looking at tendon, looking at bone, and maybe even more importantly, a lot of safety measures like how to roll out for DVTs and and other more kind of bigger scary things that you might see in the hospital setting as well. So it's good it's gonna be badass.

SPEAKER_05 58:39

Yeah, it's a pretty good course, and um it's uh it's pretty easy to do, you know, kind of you know, once you kind of figure things out, you know, what you're looking at and and whatnot, you know, obviously the heart and things like that take a lot more time, but on the muscle side of things, uh it's it's pretty easy. You know, you get an ultrasound, literally just you put it on the quad or you know, what have you, and um it's right there. Uh, and then the other thing of it is too, is there's so many different devices out there on the market now that make it a lot more clinic friendly, um, where you don't have to wheel this big card around and and whatnot. Um, you know, literally you have these little devices um with a with an ultrasound probe and an iPad, um, and you're you're good to go. Uh the technology is just continuing to kind of advance too with AI. I mean, some of the programs and what they're coming up with is literally it just it'll tell you, you know, like you it'll sit, you you put in like what you want to image, and it basically directs you how to actually do that. Um and then you know, all your measurements are done through the system. You know, you just draw a line um for your thickness, um uh for pinnation angle. You just you put the angle, put the lines there, it'll give you an angle. So it's it's it's pretty good, man. It's pretty good course.

SPEAKER_04 1:00:10

Yeah. The price point, you don't need that 40,000 for the big GE anymore, it's just a couple thousand bucks, and you can do this on your iPad, which is crazy. It's awesome.

SPEAKER_01 1:00:18

Yeah.

SPEAKER_04 1:00:18

And we're we're even in discussions with one of the companies of getting a more rehab MSK, AI driven for for the for the rehab side type of device, where it even will potentially like be telling you what anatomy you're looking at when you put it on there. So you don't even have time, maybe even have to know what it is. So it's gonna be badass.

SPEAKER_02 1:00:40

This is definitely a direction that the the physical therapy world is going too. I mean, in California, they're starting to look at practice that stuff. Ultrasound is kind of on the list of things to do. The uh the APTA has really kind of done a good job in terms of sort of um coordinating with the physicians' groups so that essentially as a physical therapist, you can hold the exact same certifications as um as a physician. Um, you just have to kind of go through and do all the all the testing and everything. And so that's obviously the goal of these classes that we'll be offering is to at least get you started on that road. There's much much longer road to kind of get there, but we kind of get you started on that, and then obviously more to come in the future for sure on that front.

SPEAKER_04 1:01:27

Speaking of ABTA too, um, they put our podcast up um with the uh going over the VTE clinical practice guidelines on on their website now. Yeah, so that's cool. Um lots of good information. If people haven't listened to that, I think it's worth listening to because the guidelines are very robust and have changed.

unknown 1:01:47

Yeah. Yeah.

SPEAKER_02 1:01:49

All right. And those guidelines are in the in the show notes. Um, if you want to download it. Also, want to mention we are sponsoring um next weekend uh OSU Lower Limb Symposium. It's being run by Matt Bobman's crew, formerly ACL Study Day, now evidence in practice. That's a really comprehensive um conference just on lower limb stuff. Some big, big name heavy hitters. Mark Paterno is going to be there, Laura Schmidt, um, Matt Itherburn, Dustin Grooms, Sue Sigward, and some other big names that um that I don't know. So it's really well put together thing. We're supporting that. We're also supporting elite hockey rehab conference in Colorado, Colorado Springs in June, and Elite Basketball Rehab Conference in Vegas in in July. And then, of course, Ben and I will be at NATA. Zach, you coming to NATA? Or no?

SPEAKER_05 1:02:47

I have not been there yet.

SPEAKER_02 1:02:49

Oh, you haven't been to NATA anyway.

SPEAKER_04 1:02:51

It's in New Orleans this year, man.

SPEAKER_02 1:02:56

Hot and humid, baby.

SPEAKER_04 1:02:58

Um, and I guess speaking of ACL, last thing we keep plugging stuff, but there's so much we've done, I forgot about it. Um, MedBridge did the ACL symposium at the end of last year that Dustin um kind of helped run, Dustin Grooms, and all of our talks are on the Medbridge platform now. If you want to go on, if if you use MedBridge, um, you can go on there and get them, I think, for a limited amount of time. But lots of good ACL information out there. Phil Pliskey and Dustin um uh were two of the folks that helped run that thing. All right, man. I gotta go to a cheer banquet. Oh boy, oh boy, uh huh. You gotta get all dazzed up for you. I didn't realize that would be a sexy cheer, dad, but here I am. So somebody's gonna bear that. There's not a bunch of fights between the high schools, really the moms I'm worried about tonight. So Mexican food, beer, and angry moms. I was gonna say just what I'm doing right now. Great talking to y'all. All right, talk soon. All right, later, later.

SPEAKER_00 1:04:10

Thanks for listening to the Owens Recovery Science Podcast. Owens Recovery Science is a single source for PCs, OTs, ATCs, DCs, MDs, and other medical professionals seeking certification in personalized blood flow restrictions rehabilitation training. Find them online. It's OwensRecoveryscience.com.

SPEAKER_02 1:04:32

One last thing before we get out of here. First, I want to say uh sincere thank you for listening all the way through. But also wanted to remind you that this podcast should not be considered medical advice. It is strictly entertainment. It's a way for us to try to keep up with what is ongoing within the DFR world. If you require some sort of medical attention, medical advice, please seek that from a licensed individual within your state. Thanks, and we'll talk to you soon.