#305 We Debate Footstrike Myths!

Hello everybody and welcome to the Doctor of the Running Podcast where we a group of doctors of physical therapy discuss the art and science of running and the stuff that we put on our feet. Today at the round table we have Dr. Matthew Klein, the founder of this fun little shindig. We also have Dr. David Solis and myself, I'm Nathan Brown. As always, this podcast is powered by our partner, Rabbit and Rabbit is a fantastic running apparel company and so if you're looking for anything for summer, gear that's really lightweight and also gives you some sun protection, you can check out what they've got going on. If you want 10% off your first order this month, we have a monthly code, so in the month of August you can use the code AUGDR10 and that'll get you 50% or sorry 10% off any order or more than $50, that will get you a little bit of a discount. But I think what would be really interesting, I don't think we've talked about this yet together is some of the stuff going on in the running world and performances particularly thinking about Josh Kerr and the mile. What was your, David, can you just fill people in on kind of what happened for anybody who hasn't been following competitive running and then we can do some reflection on it? Yeah, I mean, not to be overlooked by Cooper Luke and Houseco and 52 and negative splitting the eight to win the USA is like earlier today, that's crazy. Anyways, Josh is, yeah, he's amazing, he's always been a guy that's a go-getter and a very aggressive runner, he was an NCAA collegiate record holder at one point, back when he was running at New Mexico, I think at that time he ran 334 or 335, I can't remember exactly what he ran. He likes to get after it and I think one thing that was really refreshing to see going into this race was the sheer level of respect he had for that record and the level of work that he knew he had to do and the places that he knew he had to be in order to have a realistic shot at getting it. And I think with a lot of races and previous world records that have gone down, I vaguely remember Kerr Goucher talking about this a little bit where it's like you have these people where they're having a great season, they're in a really good shape, they start thinking about it and they're like, you know what, maybe I'll take a crack at the record and that wasn't the case at all with Josh, it was like, no, this entire year is centered around me getting this, it's not about like, oh, I'm in shape for maybe getting a gold medal this year and because I'm in shape, maybe I'll take a toss at this. It was very, very intentional in that build and whether it be the track work, the tempo work, like it was just, he was dialed in and anyone who was following that journey and looking at what he was doing, there was a couple workouts there along the way where the math is starting to math and you're looking at it and you're like, oh no, like he's got a real chance. Like this is something where like he is genuinely in shape to make this happen and he probably could have even gone a little faster. I mean, he looked great. You know, he was an uncharted territory where it's like he's going as fast as he'd ever gone and he saves per lap. Yeah, dude. Like he's circling the math on it. It's crazy. Like he's, I can't imagine splitting a 150 in the middle of a race and continuing to go. I've never even run a 150, you know, like, I'm going, yeah, yeah, 150 in the eight and then doing it again, right, like splitting 55s for the first two and then I think he got it down to 54 for the, for the next two or 55 54 cooking, he said, the one for people who don't know, he set the one mile world record. What was his time? Yeah. 342, 342. 342. So that's, yeah, that's crazy. What was it before that? Does anyone know? 343. 343. Oh, I hit him a garage. Yeah. Yeah. He still has the 15 too. If Kurt goes for it, it's 326, oh, I believe, yep. But his, I'm like, I mean, he put it down, you know, there's a reason why no one's touched it in 27 years. Right. That includes Yaka being a Briton, that includes Bernard the God, that includes Asbell Kiprop. There's like been so many good mylers that we've had the pleasure of watching who have not got it, you know, and it's, it was a steep, steep record. I put it up there with the David Rudisha 800 from London. It's, it's that good to run that 342 and to do it the way he did it. I think it just looked so commanding and so poised and so ready. You know, he, he was not running out of fear. He was just executing at that point and, um, yeah, I don't know. I, I don't really know if I have much to say beyond that. I think he did him and his coach, um, Mackie, like, the Brooks Beast, I've been doing a good job over the last couple of seasons. I think across all of their middle distance disciplines, I'm looking at, like, let's say Brandon Miller and the 800 have been running phenomenal over the last couple. He won the last like three races. He's run, right? And, well, yeah, he's no longer there. But, um, just the whole middle distance crew there are solid. And they've just done a good job of developing and I feel like they didn't quite rush it. They got him to a point where he was within striking distance. Once he was within striking distance, then it was like, do we want to go for this? Yeah, let's do it. And then just dedicate the entire year, right? And then it, because like he's peaking for that race, he's not peaking for world championships, right? Like, it was meant to happen there and then. And I think that's what's unique about that world record attempt slash success. It wasn't just like, let's go for it on this day. And after a gold medal or something, because you do see that sometimes too, where they keep racing after they get a medal, then they go for it. So peaking well before the medal opportunity and going for it at London, at home, you know, he's from the UK. So although I don't think he's from England, though, I think he's Scottish, right? I somehow can correct me on that if I'm wrong. I don't actually know. But he's, but UK doing it on the UK ground was pretty special and the stadium was super injured. That's the loudest I think I've ever heard a track stadium. I think maybe the second loudest was when Mofera won in that same stadium in London in the 5K and 10K. I think might be the last time I heard a stadium get that loud at a track meet. So yeah, very cool, huge, huge record and just massive effort. I think anyone who ran the 1500 in the mile knows how special that record is. And I remember like, even Kyle Merber was like getting emotional, you know, on the podcast with the city's mag team, also former NCAA record holder. And it's just like seeing that record go down is really the change, like a generational effort. So it's cool. I think it's, it's great. Did I answer the question? I feel like I just went on like a long rant, not even a rant, just appreciation. I guess. I love it. Appreciation. Yeah. Moment. Yeah. Yeah. Yeah. I feel like, I mean, because you still got like yard and a goose, right? You still have Cole Hawker. You have frickin' a fork it from like Germany. He had an excellent race too. I don't want him to get forgotten like just so many people that are really, really stepping up in the 1500 in mile. It's cool to watch right now. Yeah. Matt, do you have any reflections on it? Yeah. I think the two things are shoes and training that haven't been mentioned in a big shout-out. The reason I know this is because he posted about it on LinkedIn, but Brian Conrad and the whole Brooks team, I mean, good job, along with Josh Kerr, obviously a good job. Very unique shoe design that's kind of cool to kind of go, "Oh, that's interesting." Like that, it seems like, and I haven't held it or looked at it, very rockered, super spike type design, which is really interesting. So hoping we get to see more of whatever that is or like they learn some really cool lessons. Unfortunately, I didn't get to go to world congress of biomechanics, which just happened when this releases a few weeks ago. And that was in Vancouver, Canada, and had some really cool people. One of the individuals I work with, Robin, who's our engineer at George Fox, got to go up and see some cool stuff. So I'm going to pick a brain more about some of the things that she saw. Not sure if they got to talk about that, but yeah, good jobs to the team. I mean, it's a huge effort to do that. I think what's really interesting to me is talking about training more than the shoes is some of the interviews with Josh Kerr and Danny McAid are talking about, you know, consistency is really important. You don't try to do those like super, that one off super workouts. It doesn't come from one workout. It comes from slowly stacking over time. And when you're talking about adaptability and what we respond best to from training, it's not a single workout. Like a single workout can ruin you if you do it too hard. But it's being able to put workout consistent workout after workout for workout and letting your body adapt, seeing, okay, how does it respond? Is it getting better? Is saying the same? And just taking it as far as you need. And David's point going, yeah, you only have one thing to peak for. Yeah, you can build a whole season, a whole year around just going, taking these incremental steps and just hope that people realize how long it gets. It takes to get to this point because you just got to make sure you're slowly stacking the right things, don't overdo it, make sure you've got enough recovery, make sure your body is able to adapt the training. Yeah, my big take away is remembrance that the fact that this tough. takes time. And if you rush it, that's where you don't get it, you get hurt. Your body doesn't get better from some crazy workout. It gets better from consistency. So I think about that from a like training rehab, what kind of standpoint, just reflecting on what actually gets people better is just patients in consistency. I will say to also a variety of and intensity of stimuli, because he raised pretty much exclusively to 800s going into that race, which makes sense. Yeah, get that top end speed, make that 55 feel as easy as possible. I mean, he peed in the eight that season, you know, as well. And he's not traditionally a strong 800 runner. I think he got down to 145, which is very respectable, but it's not going to get you a podium at worlds, you know. So it's like, you got to get down to that pace and really have a feel for it. And then once you have a feel for it, slow it down just a little bit and lock in for four laps, you know, and that's what he did. Nathan, what'd you learn? What are your thoughts? Honestly, not much more than what y'all have shared. I am a person that doesn't follow competitive track and field that closely. So my learning about it is through you all because we talk all the time in our group chat. So, you know, I learn about when things happen from you all. And then I hear your reflection. So I don't have anything to add. I just always find it amazing. Yeah. Cool. Yeah, that was definitely one for the record books. No pun intended. That was quite impressive. Yeah. Well, let's start talking about what we have in for testing now. So this is our infrotesting segment. We talk about the different, you know, shoes, gear, whatever that we've been using lately and kind of what what we've been thinking. So Matt, do you want to go first? Yeah, I have a variety of things. Most of them I actually talked about. I'm going to save the exciting one for last that I'm really enjoying that I just held up. Still getting miles on the SC Elite version six. We'll get that review out. Hopefully this week, although by the time it comes out, it already be out. I have really enjoyed this shoe for very different reasons. I'll do a comparison review at some point with version five, but it's very different. I have liked this a lot more for shorter distance stuff for long distance stuff. Just found it a little bit too narrow in the heel and midfoot and a little bit too squirrely for me, but picking up the pace. Five K type effort has been really, really nice. So very different shoe than it was in the past. I have like 70, 80 miles on the Clifton Pro and wasn't that excited about this shoe when we started putting miles on it. But, you know, Nathan, I think we got to get this review out and I can join you if you want. But I really, if this is my left shoe, nowhere, it's doing great. That is like almost unheard of. No offense for a hook issue because hook is typically in my experience. Don't have gray outsole or mid-solder ability and this is holding up super well. I do think it is aptly named that it is a faster snappier version than the Clifton. So make sense. Do you think it aligns with other models from different companies that say pro? No, I don't think so. It should be the Clifton semi-pro is probably what it should mean. There we go. But no, it should just be called the Clifton and then they get rid of the actual Clifton. Maybe. Yeah. I mean, the only challenge is that I do not enjoy this shoe as much for walking. And so Clifton definitely is that, and again, we've talked about this before a lot of, there's a lot of classic running shoes that really more people buy for walking than running, especially in the US. And the Clifton, inline Clifton is definitely that more versatile walk run shoe. This is just that little more uptempo. It's been very nice, especially for long runs. I'm going to gush about this shoe again, even though it's low enough drop that it is annoying my Achilles a little bit. But I still, the Spectre Elite from Topo is one of my top super shoes this year. It's the ATPU foam is really fun. Great long distance shoe. I did this 10 mile progression on this morning, keeping down to six minute pace by the end. It was, it's really good. Again, my top distance racer and the outsole is still there, which is great. Despite having destroyed an outsole in quite a while. Yeah. I don't know what's happening. So my final one, which isn't, is a partial running shoe is the Adidas Adi Zero Dropset, which when this is being sent to us, I'm like, Dropset Pro. Dropset Pro. Thank you. I was just like, why do we really, and I really enjoy this? I have, with my Achilles rehab, I've been doing extensive amount of palmetrics and starting to lift a little bit more. I'm, I'm really enjoying this shoe. Midsel underfoot is really nice. I don't like the tapered toe box, but security everything else. I can understand why this might be a good choice for a high rocks or multi sport type event. I think that was going to be one of the things that I think is important. It's like, well, they didn't create this as a running shoe. What did they call this shoe for? Well, this is purpose in the desert. They're still running, though. I mean, they got 10K of running in a high rocks. Yes. I mean, yeah, but it's not just pure running. Right. Yeah. It's not, it's not a, it's got to be able to run, but it's got to be able to do functional training. Right. It's not a, it's not a great running shoe. It can't, it is a running shoe. It can run. So there's enough of a bevel there. It's a little bit flatter. It kind of feels like a little bit more of a lifting shoe. I will also say that trying to lifts, it's not the greatest lifting shoe out there, but it seems to hybrid this stuff, which again is enough that it's like, oh, this really, this, this works. And it balances a lot of those things fairly nicely. The wide platforms, great. A lot of times I really suggest that people do not lift in running shoes. Running shoes are really not designed for a lot of the forces associated with lifting. They're not designed for things with lateral movement. I've done some lateral hopping in the shoe as part of my plyographic. And it's great. So if you want that kind of all around there, I think this is such a better option than a lot of what we've had where a lot of people were doing these kind of events either in pure running shoes or pure lifting shoes. And neither one of those has a, like you shouldn't be running in a lifting shoe. They're not designed for that. You shouldn't be lifting in a running shoe. It's not for that. This blends it really well. And they've been multi, there's been multi sport athletes for a while now. So yeah, it's good. Just the toe box doesn't mean to be so narrow. That's my only complaint. But outside of that midsole feels great. And the transition's been good and good like frontal plane. I'm not going to say like stability, like arch support, but like stable platform to like be able to handle a lot of emotions. It's been really nice. Yeah. That's awesome. David, what about you? What do you got? Yeah. So I'll continue with the Dropset Pro trainer. Definitely feels like a training shoe, like in terms of like the category training shoe. I know we say trainer all the time for running. But like most people when they think of a training shoe, they think of something like this or like a Reebok Nano or like the Nike Metcon, like it kind of in that category of shoes. But I agree. The light strike pro midsole is nice. They have this encasing on it. I don't know if it's EVA or what it is, but it's like it basically creates a little bit of a cradle around the side gives you a little bit more of a stable platform, medially and laterally. And I can attest. It does feel pretty good side to side from what I've tried so far. I haven't run in it yet. I still need to run in it. But I have done a couple other things. I agree with you on the forefoot taper. It's a little bit tight up front where I'm like, especially for a lifting shoe, people really like wide toe boxes and having good volume there. So it's a little bit uncharacteristic there. But the bevel is not too bad. You know, especially when you need a flatter geometry, like, it's like just enough to do okay with running. And they got some energy rods in there too just to make it a little bit of a different platform. But I won't go on more about that one. We've already covered that. I'll briefly go over the SCLE version six because you went in over that too. We've actually had different experiences for me. This is something where I'm like, I could wear this for 26, like pretty easily, I think maybe the most easily out of any of the super shoes so far this year. Yeah, it feels great at easy and rhythmic paces for me. Like it feels like a marathon shoe and not that it can't go fast. You know, I just feel like I don't get as much umph out of it as I do. And like, let's say the hyperwarp pure or even the DV8 Elite like from Puma, like if I'm trying to go fast for 5K 10K, the weights there though. I mean, it's sub seven ounces. Like it's super light. It's got good cushioning. It is a good foam. Like so you totally can run a 5K and 10K in it. I just feel like the way I interact with the plate and the geometry, it feels better at longer like efforts for me. And I think the wide forefoot is nice with that. The collapsible kind of like midline heel groove there feels good for that. Like it just likes, I like to get into rhythm in this. It's not one of those shoes where I like to be aggressive and I'm like really pushing off that forefoot in it. So I don't know. It's a really nice shoe though. I think right now it's in the potential conversation of a top three super shoe this year for me. It's kind of a funny one because I feel like I wish the foam just wowed me a little bit more. I think from a responsive and bounce standpoint, but everything else checks very, very well. And the weights there and everything else is there. And if I truly had to run a marathon tomorrow, it would be on the list. I'd have to look and narrow things down and go, okay, what am I going to actually pick? It for especially releases this year, it's it's 1,000% on the list. So yeah, I've been enjoying it. And then the other one here that we haven't talked about, this is the Solomon Arrow Blaze 4. I did a 10 mile earn it just the other day. It's a nice shoe. You know, it's kind of that lightweight versatile trainer for Solomon. It's that beaded TPU that you've seen in the arrow glide as well. Good traction underfoot. You got the conser grip here the forefoot and then kind of the like outer rim that thick out so rubber I'm going to try and put it up to the camera there and then you've got kind of a little bit of a groove here. Now this sheet does have a pretty narrow midfoot. I feel like however they did the shaping of this shoe and the change in the upper, it feels more secure than the three, thankfully. I had a hard time with the three just because of the instability in the midfoot. I will not say the issue is stable in the midfoot but it's a little bit better than the three. So I would just like them to work on that midfoot stability honestly, if there's a way they could figure that out like, but it's light, it's versatile. I got it down to like 540s, just fine. And I had no issues like it actually felt pretty good. So it's just a lightweight versatile trainer. I think there's probably better ones out there right now. But it has a lot of potential to be, you know, on the top of the list, I think it's just not there yet. And it's a more narrow fit too. You can feel it kind of like squeezing the lateral side of your foot a little bit. However they did the wrappings on the inside. And the tongue is not gusseted. So I don't know why I'm feeling that so prominently. I think it's just the way the shaping is, like the lower volume. And then the last one on the list here. Actually got two more, but it's, this will be super, super fast. Review coming out, we've talked about this before. Plenty of times Adidas Terra X or Graphic SL wrote the review. It'll be coming. We have our new website now. So like things are starting to get released again. So that was more delayed because of those reasons, not because of anything else. But SE Rebel from New Balance is the other one. Sub-8 ounces, performance trainer, lightweight, super trainer, like Infinion midsole as well, same as like the SELE, but it's a four millimeter drop, so it's 40, 36. I actually love this shoe. I think this shoe has been a massive home run for me. It's like, we talk about shoes that you just kind of want to grab off the shelf. And this is like the one that it makes running more fun. It really does for me. I think, however, I integrate, like where the plate, like pittets is right where I land or not where I land, but like right where I strike like through my forefoot when I'm transitioning at that point. And I just fall right off into the next step, but not so sharply that I can't actually use the forefoot either. So it's like snappy and bouncy, but it's soft in the heel, really firm and snappy in the forefoot. It's like kind of what I've been wanting out of a shoe. So it's really fun. It's a unique experience. You know, I can totally see someone hating it, but I do really like it. - It reminds me of the feeling of the plate. Reminds me of the Skechers M-Strike. - Little bit, is anybody else notice it? Am I just crazy? - I haven't ran in mind yet. I have a half size up coming. It's too small for me, so I haven't ran. - I think it's like the abruptness of that transition where M-Strike felt very prominent. - Yeah. - I don't know that it feels like M-Strike to me, but I can see where you're getting that. - Yeah. - 'Cause it is so obvious, right? You have that like soft heel, and then it's like snappy over in the forefoot. - Yep. - Yeah, and I think however I land, like the geometry works really well for me, where like that soft heel, I literally just load into the plate in a smooth way. But I think if you don't land into that plate in a smooth way, it could probably be pretty jarring. - Yeah. Cool. - Nathan, what do you got? - Not much, nothing new for me in this last week. I've gotten more miles in the on cloud monster three hyper. I've gotten miles in on the topo cyclone, or sorry. Yeah, no. Oh my gosh, what's it called? - Spectre. - Spectre, oh my gosh. - Yeah, that's okay. - Topo Spectre three, which when I did that, it did continue to require my febularis muscles to work more. It's just a little squirrely through the midfoot, so I could feel that afterwards. I have to limit how long I go on that shoe, I love the ride, but my current status doesn't match it 100%. And then I just wanted to give a shout out to another topo shoe, the ST6. It's my favorite lifting shoe. I just could do jumping stuff, cutting stuff, 'cause I do some multi-directional work right now. It's got a low platform. I think it's like 15 or 16 mils, zero drop. Just super great, love that shoe. So that's pretty much it for me. Nothing too exciting right now. So as always, our infertesting segment is fueled by scratch labs. If you wanna check out any of their stuff for in-run, pre-run, post-run, fuel, nutrition, et cetera, et cetera, you can go to scratchlabs.com. You can use the code Docs of running for 20% off your first order. I, Matt's gonna eat some right now. - On air, he's gonna, yeah. - We all have it, 'cause I-- - We all have, yeah, he was pre-recording. He was eating some and I was like, you know what? - I brought my dad. - I want some chewies. - Sorry about that, everybody. But they made a big bag of their energy chews. So I actually use a more pre-run, like as like a snack a bit before, just to get something in my belly, 'cause I run so early. So that's been nice. - Yeah, it's nice to not have the big bag and not have to like open one of the smaller ones, be like, and like gonna eat all of these, like how much do I want to be able to like adjust that is really, really, really nice. So, love the bag. - All right, so the main segment for today, we are gonna be revisiting a topic that continues to be one that people talk about with their friends. They talk about it a lot with their PT's as a PT. People ask these questions all the time. I think that social media loves to continue to push certain messaging about this topic. And we've talked about it in the past, but it's been years since we've visited this. And so we're gonna be talking all about footstrike. The goal of today is to talk about what footstrike is, first, very quick flyover. Then we're gonna talk about common myths related to it. And then start to think about what sort of features of shoes might be something that you could think about. The first part is gonna be pretty cut and dry. We know what footstrike is. We have some running myths that are related to some literature and experiential and things like that. The last part when it comes to shoes, there's a bit less of the literature, a little bit more about applied biomechanics and some things. So it's not a perfect one for one. - A bit less? - A lot less. - A lot less, maybe none. So it's gonna be a neat conversation from that aspect. So before we start talking about running myths, let's get some nomenclature down and talk about what footstrike is. So when we talk about footstrike, we're referring to that moment when you are coming out of flight phase and your foot first contacts the ground. Typically there are three different places that your foot can touch the ground first. Sometimes they delineate into four. So I'm gonna talk about all four and then we'll be able to jump into some common myths about footstrike. So when you think about footstrike, you can either land near the ball of your foot which is considered a four footstrike. You can land with kind of equal distribution between the ball of your foot and your heel. They would call that a mid footstrike. You're landing in the middle. Then you can land more on the heel of your foot. They call that a rear footstrike. And then if you land very far onto your heel, they call that a heelstrike. So some researchers delineate between rear footstrike and heelstrike and we can talk about that a little bit later, but those are the four categories. The three most common are gonna be rear footstrike, mid footstrike, four footstrike. In the more hardcore biomechanics literature, they usually delineate between two and there was a lot of arguments about this going, you're either a heel striker or a four foot striker and there aren't any variations. So be aware that you will see variation in the literature, you'll see variation online, how people talk about this. So it just really depends on who you are talking to. I don't think either one is wrong just people have different opinions. So if you see something different, no, it's not like people have jumped ahead with a lot of opinions and not really done some of that foundation of work of like, "Oh, how do we categorize?" So people just jump ahead with things. So you may also see two. - Yeah, and then they might even say, you're either like a heel striker or a rear foot striker or a non-rear foot striker. - Yes, the other, yeah. - Yeah, it's like, you're this or you're not that. - You added an extra letter to the abbreviation instead of say, do you usually RFS or FFS? And now they went RFS or RFS. - And RFS. - And RFS. Why are you just looking for a different work? Why? - And we might get there, but I think that part of that is they're looking at what are the biomechanical implications between a rear foot strike and a non-rear foot strike, and then they basically found like, mid and four foot have some more similarities than differences, and so creating three categories doesn't necessarily matter if the landing mechanics don't change the demands on the body. But we might get there in a little bit more detail, we might not. - I know. - Where we wanted to start though are some common myths about foot strike. So I have six or seven of them here, and I'm gonna give the myth, and then y'all can kind of dig into that myth a little bit more, and maybe why it exists, and why it's a myth. - And the goal this, by the way, isn't to like poo-poo on anyone. We are presenting you with current best evidence, like the stuff is done in the last few years, it was not super old literature, it's very up-to-date, new, systematic review meta-analysis, taking all the stuff together, and to be fully honest with you, a lot of research papers I've seen recently, and even a few that I have been a editor on, or not editor, but a reviewer for, in today's world, we'll still get this stuff wrong. And they're like, Well, I'm like, that's you have no evidence to support that the current literature says this. So no judgment. We're just presenting to you what the best evidence is now. It's not low. It's pretty good level. So these first two myths are two sides of the same coin. So I'm going to put them together and then we can talk about it. The first myth is that heel striking is bad. And the second myth is that forefoot striking prevents injuries. So why are those myths? Why are those perpetuating? And how do we know that they're actually myths? Matt, do you want to start us on this one? Yeah. So a lot of this has been perpetuated by four quote unquote form experts or a lot of the individuals in the barefoot natural running thing, which the idea that some of this they pulled from Daniel various amount of areas, but Daniel Lieberman and some studies like, oh, you know, we have this one small observational study going to Kenya and seeing that a bunch of people forefoot strike. And that must be more natural, but they failed to also note that there was variety among the landing mechanics in a variety of places. And but a lot of them were like, oh, it's more natural than your forefoot, because that better utilizes the Achilles tendon and the gastroaxalius complex. You're going to be more elastic. And if you're if you're heel striking, when you land on your heel, biomechanically there, so when you land, if you look at ground force or ground reaction forces, which is the impacts, like it's when you run out through a plate, for example, that picks this forces up, the ground reaction force is the opposite reaction. You have to have an equal and opposite reaction for every force that's applied. When you hit the ground, the ground reaction force is the opposite force that goes back into your body. And when you look at this on a graph, when you land, you have this kind of curve where it picks up really quick, you kind of peak, and then as you go to push off, kind of decreases in a way. Okay. So when you rear foot strike, there's there's an impact peak where just that imp, there's this extra peak at the beginning of that increasing curve. And a lot of people were like, oh, that's extra. That must be what causes injuries. Rear foot striking must be bad. But the problem with that is they made those assumptions. And then Nate is holding that down below, going, yeah, that with a non-rear foot strike, that curve is smoother. Well, they made a lot of assumptions. And then when they actually started studying, hey, is that impact peak related to injuries? The answer was no. It wasn't. There was not like, there was awful. There was no correlate. It wouldn't even correlate to injuries. And then they went, well, okay, so now they're actually studying this. And we don't see a relationship between that impact peak and running injuries, which it could make sense, right? You have this extra little peak, right? Maybe extra force theoretically would potentially put your risk for injuries. But then they found, hey, that's not actually related to injury risk. And they did a bunch of different, like longitudinal studies looking at it and no relationship, no statistical significance, not even close, actually. And so then they went and got, all right, well, as scientists, let's look at big populations and try to figure out, is there a relationship between running injuries and foot strike? And the answer was no. There is no different in injury rates. How many people get injured between those that have rear foot strike, foot strikes, and non-rear foot strikes? There's no difference, not even remotely stats aren't even remotely close. And so if you're looking for in and to take that even a step further, changing movement doesn't seem to reduce injury rates across the whole population. And they've done it. There's additional systematic going, hey, if you change your cadence, if you change your this or you change that across the entire population, it doesn't change that, maybe in some small subsets of populations. But that's not going to reduce your injury risk. And unfortunately, it's not a panacea. Unfortunately, that's what a lot of social media, so, oh, what's the one thing that's going to fix it? Sorry, life is complicated. And this is not any different. Now, there are different injury types between the two or three or four, because depending on where you land, you are loading different structures. So there, those relationships do exist. They're not that strong, but at least it's, you know, there's some significance there. So regardless of your foot strike type, you're not going to have better or worse rates of injuries compared to someone who doesn't, right? There's going to be some unique outliers, obviously. But what is going to be different is what tissues are getting loaded and potentially injury risk associated with specific tissues. And then you can extrapolate that, but we don't have the evidence for this. And this is, I guess, there was a problem going, hey, you know, if I, this is how I run, these are the tissues I might want to make sure are really durable and make sure I built some resilience there. But that's probably as far as I could say. So no, there is no injury benefit to one versus the other. There was some early evidence that one was actually more efficient that rear foot striking was more efficient than the other one, because then we'll get to that later. And we'll get to that later. But there's some stuff recently that's kind of also muddled that and that also might not be true. Yeah. So so David, can you talk a little bit about those differences in injury types? So four foot strikes may experience X, Y and Z injuries, whereas heel strike may experience others. Can you break that down a little bit? Yeah. So Matt touched on this a little bit already kind of talking about the Achilles getting loaded more when you're in a more planner flex position landing on the four foot there. But I'll start with the rear foot. I think it's a little bit more obvious like when you're landing at your heel, your foot is transitioning downwards towards the ground. Something's got to put the brakes on that so that your foot doesn't just slap and nail the ground. So in doing so, what gets loaded a little bit more from a rear foot strike is going to be your tibialis anterior on the front of the shins. And then you're also going to have a little bit more like proximal stability things kicking up both at the glutes and in your quadriceps. So the way the loading profile ends up being a lot of times you might be a little bit more predisposed to having some anterior on the front kind of like shinspin type pain, the front side of the knee like a runner's knee type presentation. And again, this is not exclusive like if you heel strike this will happen. It can totally happen on both sides, regardless of what foot strike you have. But just kind of more commonly, yeah, or like proximal kind of like glute knee kind of tendonitis type stuff or glute max. And then if we're looking on the four foot strike, you're a little bit more forward when you land. And now your foot is in more in a planar flex position. It's going to load more of those posterior structures now. So you're killies, your calf complex. You get a lot of strains there. Get a little bit of quicker heel rise sometimes. So you can see some hamstring strains depending on like if people aren't quite used to being at speed or like if they just they're getting earlier heel rise, they're transitioning cadence or something. But that can happen. But that's probably what I would see the most on the four foot would be like that gastroxoleus complex and proximal hamstring probably. Yeah. The other areas I might add just from a normal impact factor is you are probably going to see more like went from a bone stress injury in the foot. You're probably going to see more calcaneal stuff and a heel striker because four foot strikers don't load that as much. Just as you may see some more four foot kind of bone stress stuff says moid stuff to the small bones under the big toe or metatarsal type injuries and bone stress injuries with those who land a little bit farther forward. But they can happen. I have seen the opposite. I'm like, how do you get this? Runner is getting hurt. Yeah. That's essential. Yeah. I will, I will also, we'll also note David made anyways of getting hurt. Yeah. David made a great point about like the anterior shin splint type symptoms just because the antibus working. Four foot strikers can also get this because their shin splints is a catch all term. You can get shin splint type symptoms from anterior or posterior structures because we actually know that ground reaction for like the impact into the bone that you get when you land is nowhere near as high as the impact forces from your muscles contracting on the bone. So one of the other contributors can be of this can be soleus pose tip which attack directly on the back of that tibia. We found, hey, actually four foot strikers can also get that as well. We just notice more of that shin splint type symptoms that we generally associate with like I do that with antib but we have to realize both groups have things that can pre-expose to those symptoms but absolutely. And by four different topics. Are you team tib ant or antib? Tib ant is what I say. I'm tib ant. What did I say? You said antib. I mean, neither is wrong. Right. I mean, technically what is wrong now, what I keep saying is peronials where it should be fibular muscles now. So I've gotten get out of here, pranius longus for life. The cranes more anatomically correct verbage. print. Get out of here. No one clature from anonymous and somebody can correct me in comment. But I believe it is fibularis but I can't help but say peronials. Anyway, sorry. So if I were to summarize, you know, the myth is that heel striking is bad. It's not, especially when it comes to injuries. It's not. The other side of a coin is that forefoot striking does not prevent injuries. The injury rates are the same between them. What is different is typically the injury profile. So if you are listening to this, that's the big takeaway. injury rates are the same injury profile. might look different. All right. Myth number two is that all or most elite runners, though, aren't going to forefoot strike. David, do you want to take a look? Oh, yeah. Yeah, I mean, I said, like 98 or 99% of runners, he'll strike. It depends on the study that you look at, but it's like anywhere from like 70, 75% up to the 90s that a lot of people. Yeah, even even within the elite distance runners, that's what I was going to say. That's including elites. Yeah, still see it gets it. There's a little bit. There's a lot. I would say there's more vary in the literature. There's more variation. Not necessarily one more than the other, but it's more variation elites in the recreation runners. It's much more. Yeah, when you said most a lot of people refer to strike. And also a lot of the people that think they forefoot strike are rearfoot strikeers. We are awful at telling exactly how detecting how we land. And there's actually a couple of research studies on how bad we are. It was like 50% of people were right in that study. It was like half the people got it wrong. Less than that. It was even more than that. That like, it was just awful. That's variable. You know, I can even feel it on myself in the middle of a run where it can be variable, depending on the grade, depending on the type of footing you're running on, depending on a lot of different things, pace you're going, right? Like if I'm going a lot on 100, chances are, I'm probably a little bit more on my forefoot. If I'm running a 5K, you bet your bottom running through my rear foot. Like, I can't sustain that on my forefoot, nor do I want to. So it's, yeah, it's just definitely variable. And you see it amongst the elites as well. You know, you can use Ken and Ace of Akele as an example, but it really isn't unique to him. It's everyone does it. But yeah, I would encourage you next time you're watching an elite race. Well, like Yakub, he's on his heels too, right? In the 15 in the mile. I'm pretty sure. Yeah, I was just watching a training video of him because he's running again. But yeah, I mean, a lot of these guys, you know, some of the fastest people on the planet, you know, do rear foot strike, even at faster distances. It's not exclusive to speed. It's not exclusive to, you know, your ability level or distances that you're running or footing and stuff like that. It's just variable things change. So this kind of leads us into our next myth is that running economy is directly determined by your foot strike pattern. And so Matt, you had started alluding to this. What did you want to say about it? So that basically means you're more efficient if you have a forefoot strike. That was kind of the myth. Yeah. Some of the, some of the recent, or earlier recent literature was like, oh, that's actually not true when you actually do true economy running economy testing with the whole view that, you know, the original thoughts and some of the original evidence was that rear foot striking was actually more efficient just because it supposedly used less musculature, right? Compared to the very expensive gastroxolius complex being used with forefoot striking, maybe being a little bit better for the sprinting shorter faster stuff, which kind of makes sense. More recent literature has suggested that it's actually very specific to the individual and one across like it's as you said, I'm going to keep using this word. It's not a panacea. It's very unique to each person. Your experience is where you are now. What we do know is super inefficient is trying to change things. And it takes a very long time for your nervous system either a adapt to it for it to be become permanent and for it to become your quote unquote normal like it can take years. There's some evidence that to safely transition between foot stripes can take anywhere from like six to nine months and even then it may not be natural. So whatever your body is kind of figuring out that doesn't necessarily means the best thing there are obviously outliers of people are going actually this, you know, for you, this might be a better way to load, but across the population. One is not necessarily better than the other. Whatever is uniquely optimized for your body, which will be completely different is probably one of the better things. But between the two, not major running economy differences across the population. I think something that Matt said there just to highlight a little bit further is that and we're going to get into changing foot strike later. But when we run, we use part of our brain that basically activates a continuous motion. And then there's some level of thoughtlessness that comes with the activity of running. You don't have to think about your running form. You just do it. It's happening and then you can talk with your friends or you can zone out and think about the world. That's a lot why people love running. You can just zone out and go. When you change running, you have to focus on it. And there's an energy cost to focus. And that's where there's studies that demonstrate a long period. And I think that the even for cadence retraining, it was like four to six weeks where you had decreased running economy, even with a more quote unquote biomechanically efficient gate, because it took the mental toll, there was a there was an energy cost to that focus. And eventually your body can adapt or sorry adopt a new pattern that it activates for that run. But it takes a long time and that between is going to be challenging. I think of it akin to like a baseball player trying to change their swing. Their batting average goes down as they change their swing. And then it might come back and get better. And that is kind of the same pattern that you might see with with running. It's also we saw that last MLBC is in at the start with the torpedo bats. That's a great example. Yeah. When you introduce something new, people have to learn how to optimize it. And that takes a while. And how long that takes can vary. But a lot of people will take a long, long time, which is why I will say clinically changing footstrikes is one of the last options, because a like time wise and then bang for your buck, there's a lot of other interventions that I can do that will improve symptoms resiliency and get people back to what they want a lot quicker. That is a last possible thing. You got to be in this. This is going to take a while, you know, kind of thing. Changing movement is very hard. Yeah. I don't care what you see on social media. Motor control. You can't motor control is what this one thing took away my injuries. Yeah. Cool. You're an outlier. That's nice. As we're halfway through these myths, I want to reiterate something Matt said early on. What it may sound like is that we are poo pooing on forefoot striking. But we're not. What we're doing is bringing up myths that we've encountered a lot of clinicians and that we encounter on social media. And I have never had a patient come to me who was kind of naturally a forefoot striker saying, I'm going to change my footstrike to rearfoot striking because there's so many benefits and forefoot striking is going to injure me. But I have heard the flip of that 10 million times that they come in with an Achilles injury. They said, I've been changing my footstrike to go into forefoot strikes. I know the heel striking is bad. That has that conversation as a clinician has happened for me countless times. And so just remember we aren't out here trying to stop people from forefoot striking. We are just trying to level the plane feel a little bit because of what the evidence has to say. So let's move on to our next myth. And it's that changing your footstrike is a easy fix for your pain. So if you have knee pain, you should switch to a forefoot strike. Or if you have Achilles pain, you should switch to a rearfoot strike. They're I mean, I mean, I mean, like could it bring the pain down in the short term? Sure. Yeah, I don't know if it's I don't know if it's advisable. I have used this as a brief technique going, hey, this reduces your symptoms at the moment. Cool. If you absolutely have to keep running, this is something you can work on. How much you're actually doing is going to be variable, but you're basically changing loads. However, that's not going to fix the problem. If you're coming in with an injury, you need to get that injury to heel and you need to rehab it properly. I can't promise you if you change your footstrike or the pain goes away that you've actually restored completely the function in that area. If you've restored the ability of the area to handle load, to appropriately generate like a force in the area to generate power. I can't promise you, it's a breed like David said, I think you put that hit the nail on the head. It can be a great way to modulate symptoms, but it is not going to fix the problem because you're still a lot of running injuries are a load management problem. You're not recovering enough. You're you're you're over training, you're, you know, a variety of sometimes crap just happens. And so not consuming enough gummies. Yeah, I'm not consuming enough scratch gummies. So learning and there's no magic fix is just like, okay, so you have an injury. How how significant is it? Do we need to stop training? You know, what do we need to do to get you back to where you're going? Right? That's it. There's not a one quick fix. It's a unique evaluation of the human being in front of you, understanding the unique position of where they are and where they need to be. And it can be a great it's part of the running course that I teach with a buddy of mine. We do teach like movement changes that you can do to try to modulate symptoms, but that should not be the end all be all. It's just a brief symptom modulator, but there's an underlying tissue injury that that you need to appropriately address. And I think that the language of the myth is that Again, that foot straight. changes are an easy fix. They're not. They're the hard fix. They're a hard fix. And they don't address the underlying problem. So yes, you can shift forces around. But if you just do that willy nilly, you could be overloading something else that you don't have prepared. And so I think that it's risky to just go about changing your foot strike because you think it's going to decrease your injury risk. That is not an easy fix. We talked about how much your brain has to actually change its pattern. We look talk about loading rates and patterns between four foot rear foot strike. Just not it's not an easy fix. It's a challenging fix. So there are there are easier movements to change like if you're having knee related symptoms being like a slight forward lean has much better evidence for kind of changing loads. But if you're trying to change the end of a distal extremity like that it's there's a lot of nerve input in that area. And now as Nate mentioned you're trying to do something that's a repetitive type thing that we the neuro professors I work where they're going to get really mad at me because it's more complicated than this. But we often call this a spinal level activity meaning a lot of the repetitive stuff is going to spinal cord and back like just and it's obvious. It's more like we're almost almost reflexive. When your brain gets involved with that especially with an area that has and your feet are included with so much innovation it's not easy. Your body's like screw this. This is hard. I want to go back to what's easy. Yeah. Those are called the central pattern generators. Right. So it's like a central pattern generated automatic. Yeah. Continuous movement. Okay. I've got one more myth for you to stop saying I need to stop saying spinal level because that's like not correct. But it's not completely incorrect. Yeah. It's it's a lot of it. Well, the neural folks talk about it. They're too many smart. This is going to be just ravaging in the comments. No. Instead of ravaging bring us the knowledge. Bring it on. Okay. And this last one David you had touched it on it already. But I think the last myth is that my foot strike never changes. I'm always a forefoot striker. I'm always a rear foot striker. You had talked about a few things already David. You talked about speed. You talked about hills. Is there anything else that you want to bring up on that front that foot strike never changes as a myth? That's a rain. I mean, have you ever run on a trail before? Yeah. Like you're not going to land the same every step. Yeah. You just aren't depending on yeah terrain turns hills speed the foot where you're wearing. If you're in a track spike versus a big fluffy hookah like there's different things that can change how you interact interact with the ground underneath you. And yeah, foot strike is variable and it can vary based on many different things. And sometimes it could just be how you feel that day. Let's say you're super tired and you're just not quite as springy as you normally are. You might be running a little bit more like posterior a little bit more laid back like sometimes that can happen. And even within a race, you could even within a race within one race. All the time. Even get tired. They start doing this. Yeah. Yeah. Some of the most elite runners in the world what you will notice them. This is the challenge with a lot of bi mechanic studies is they will take somebody when they're fresh at a single point in time. But when you actually watch someone as they fatigue or throughout a full race, what a lot of the elite athletes do and you will see this across road across trail is they will adapt and use whatever's not fatigue just to be able to shift load like somebody that's a forefoot striker. Some of the best people actually shift to a rear foot strike is like, hey, as this set of this movement or these structures get fatigued, I'm going to shift and use these other ones and just go back and forth as I need. The other thing is and David's totally right as terrain varies. You absolutely should land differently. You need to be adaptable and you'll see this again for cross country athletes Kennedy to be Kaley is a great example of that who he would do whatever he needed to get forwards. And I need to be very careful because I'm going to extrapolate from a group here. And so sometimes doing this isn't always the best. But in the geriatric literature, we actually see that those people who use only one movement pattern actually do worse and have greater risk for falls and typically lower gate speed than those were able to actually use a variety of movements and you see some adaptability like you want to see people do a couple different things and be adaptable because that means you're going to adapt to terrain to loss of balance, to a fatigue. And so you see again not as well documented as opposed to the geriatric literature, but you should use a variety of things. You should use what you need to that's most efficient at that moment. Yeah. That's great. And I actually did a running analysis on somebody two weeks ago now in our running clinic. And they were a four foot striker on one side and a rear foot striker on the other. So even within a runner, they may demonstrate different strength patterns. So it's all on the table. It's all it's all fine. It can all be good. And also be very careful. There's going to be some people are like, oh, that asymmetry is going to cause it. It's the same thing with asymmetries. They do not necessarily predict injury. The literature on that has been very challenging. So that may happen for a reason that we don't know. So before you, if there's no problems, I'd be very careful about changing things. Yeah. It only matters if it does. Yep. All right. So let's move on to this next part for our last segment here. We want to talk now not just about these footstrike myths, but now you may know that you are a rear foot striker or you are a four foot or midfoot striker. And you're thinking about footwear selection. I think one of my top pieces of advice is like, find other people who are testing a bunch of shoes who match your footstrike. So on our team, we have Andrea. It was a four foot like mid to four foot striker. People who are also doing that, listen to her experience with different shoes that she's putting on. I would just deviate you that way. I know like, Kofuzi is also a four foot striker. He'd be another person that you could go see what it's his experience running in this shoe. But what we want to do first is talk about features of shoes and maybe shoe examples. For if you're a four foot striker, these things may be of benefit to match what the demands are of running rear foot the same thing and maybe some examples of shoes. What do y'all got for that? Yeah, I mean, well, so we all have our own like preferred movement pathway that we go through. And I think that's important to bring up because that changes the individual characteristics. You may be looking for in a given shoe and a specifically with a client, like you tend to like shoes that have a little bit of bias that kind of roll you inwards, right? Yeah. And so like I actually have an audio pro for here just to show like a kind of immediately kind of bias you that way a little bit. There's different things you can find in your own personal mechanics that for medium lateral movement that reflects some of those things. I know with Andrea, she tends to be a little bit more in that supinated position. She likes a lot of lateral soul flair. I'm super sensitive to that. So there's a perfect example where like if it goes too far lateral for me, it's not working, but she might love it, right? And that's regardless of heel or four foot strike. So I think just kind of finding your own unique pattern first and kind of getting an idea for what you like and finding a reviewer that matches kind of your strike pattern a little bit or at least preferences can be huge. But when we're talking about the rear foot, specifically like most people are going to land on the lateral side of that heel. And so I actually grabbed the on cloud runner because they have a posterior lateral bevel. I think that's a pretty solid example where it's rounded a little bit more on that lateral side. It comes up just a little bit higher. It creates a bias that eases that transition when you land on that lateral calcaneous and you're now moving into pronation. It makes it less jarring. So if there is like a big heel flair on there, you're going to land prematurely. It's going to feel a little clunky. Might be a little sloppy. The idea is to make that smoother. And so that's when they create an asymmetry on purpose, right? In the shoe to just ease that transition. That's one of the bigger ones to look for. A lot of people will do fine with central bevels and things like that. Finding what grade of bevel you like. Some people really don't need that much of a rounding. Like maybe they are more in the mid foot, four foot. Maybe they are rear foot, but they're not aggressively rear foot. And I think if she's like, let's say the magnify where it's like got a little bit of rounding, but it's not super aggressive. Same thing in the four foot. When we're looking at the four foot, you know, I think finding that one's a little bit more trickier because I think there is that natural rounding of where you push off. And we talked about this with the SC Rebel a little bit earlier where I think it really aligns with my mechanics where my met heads just like land on it perfectly. And I just transition right off the front where someone else, if it doesn't line up with their mechanics, it's going to feel awful. And that's regardless of a four foot or a heel foot strike, but more of a sagittal motion type of thing. But I think you got to find how what works for you essentially. And I think with the four foot strikers too, there's a little bit of an added element where that position is already a stiffer position on your foot usually when you're landing. It's just a little bit more of a rigid lever arm. And so some people actually tend to like more flexible options. That's when you look at like the barefoot kind of population where it's like more lower profile. So you use flexible designs and a lot of people who tend to gravitate towards four foot strikes. Some of them do really like those designs. Some people do like stiffer plates and just finding what works for you from a transition standpoint. But we've talked about this at length with other things too, but just making sure you have good mobility and good other requirements for some of these types of shoes. Because if you don't have, like, if you have Alex Rigidis, like running at something super flexible and just jam in the crap out of that great toe, probably isn't great either, even if it lines up with the other checkboxes. So that's kind of a long winded and roundabout answer, but I hopefully got that across well. I think that was great. And I think one of the things you said that was so poignant in the beginning was right now we're talking about footstrike, but the reality is that that is less of a determinant of the shoe that you're going to want than all of the other factors that ultimately result in the comfort filter. So it's like footstrike isn't going to be exact. However, you also brought up some really important things about like where you land and then what that may lead towards. So I don't know how good this will be, but I, and there's some errors in this. But what I drew, this is for people watching, I will describe it. What I drew is basically a, you know, pathway of center of pressure as you're moving from strike to toe off. And so when you look on the picture of the, the rear foot striker, you're going to be landing on the back outside of the heel. So post your lateral heel. If you're having thought about this much, usually I have runners come in and they're like, I know I wear that part of rubber and they're almost like ashamed. Like I mean, I know I'm landing on my heel and it's not good for me. That's another whole thing that I hear from people. It's okay. But you land on the post your lateral heel, which is why David said the post your lateral bevel can be helpful. And then you kind of slide up to the mid foot and then towards the big toe and toe off over the big toe. When you're a mid or four foot striker, you're landing on the outside, but up the, up the chain up towards that mid or four foot depending on how far you land. Then you kind of move backwards that center of pressure moves backwards on the foot a little bit towards the heel and then it goes up to the toe. So I think that when I think about that pattern, I really care about what's happening in the shoe at that initial point of contact. So depending on who you are and what your needs are, if you are a rear foot striker, that bevel is going to matter a lot more. You're going to need one that matches your, your needs and your preferences. If you're a mid or four foot striker, you're going to really care about what that sole flaring is doing on the outside. Because for some people, too much sole flare is going to throw you into pronation, which again, pronation is not bad, but it might throw you into pronation more than you can handle. Whereas somebody is going to want that lateral stability, like Andrea wants some lateral stability. So it's really going to depend on some of your specific needs, but an area of the shoe to pay attention to is where you're landing and whether it's beveled or has the appropriate amount of sole flare for you. A person who's a mid or four foot striker won't care if there's a posterior heel flare because they're not going to land on it. Whereas for me as a rear foot striker, that's going to matter. The other thing that I think is interesting is if you can notice for the mid four foot strikers, they're really not hanging out in the heel, but they do, depending on how forward they land, they might be landing for some of these shoes that are rockered. They might be landing beyond the start of the rocker. And then they have to rock back up that rocker because they go backwards in their center of pressure and then go forward. And I think that there's been times when I've worked with people who are four foot strikers or even just talking to Andrea, where some of these early rockers, she almost like lands on the rocker, since she can't really like use it. So I'm thinking about it's hard for her to go fast in the topo specter. Why can't I think of it? Yeah, specter, right? Specter. Specter three. Yeah, the specter three. That one's hard for her to go fast and I think part of it is because it's such a abrupt transition onto that rocker. She's landing on that rocker and then can't just like get rhythm because she can't move off to on. She's just like on it and it feels awkward. And so I think that's another important thing is to pay attention about how early does a rocker start for you if you're a mid to four foot striker and does that influence where you land. Because if you're landing on it, it might feel more challenging to really maximize the use of that shoe. Matt, what do you think? Yeah, I just want to emphasize that that probably the two really major things are where three. Where is the cushioning technology? Like I would bet, I need to ask. Did she get the new Nova Blast? Do you remember? I don't. I don't know. I'm very curious because that that shoe, I feel like if you land farther forward, it feels so much better than if you're a rear foot striker. So again, where is the cushioning? And we have such better options down the past. All the cushioning systems were always in the rear foot. Now we have a better spread of like, Hey, there's actually some decent midsole height to the four foot or there's some little more stuff in the four foot that makes it unique, which is great. So knowing where things are and how you're going to interact with them, that's kind of the key. Soul flair. So again, how much is in the four foot? How much is in the rear foot? It's going to vary depending on you and where you land. So someone, some people may really like a lot of soul flair in the four foot. Other people may not, right? They may land and either that's an abrupt landing and other shoes. If it collapses well, that it might actually ease your transition and depending on whether it's curved or not. And then as Nate said, and David, the rocker. So like a real a heel bubble is going to be more important to a rear foot striker, which makes sense because he's that transition in in the same way. How the rocker is done for a four foot striker is important because in Nate hit this on the head with Andrea, I think that if that is too large of a rocker, if you land up there, you're landing almost like in the rocker, which is a four foot striker. And somebody can correct me wrong. Sometimes that just feels weird. I've had people describe that as like it feels like like I'm there's like extra distance. I have to go to hit to like land in the shoe. And then towing off like you're just kind of in this weird transition. There's nothing to rock with. You're just like on it. You're just like that's a better way of saying it. And so some people may some four foot strikers, like especially a little farther up, may do better with a little bit later rocker so they can actually transition through it rather than transitioning in it. So, and of course, there is going to be different variations of that. So knowing the cushioning in the area that you land, knowing how like the soul flare effect you and then how do you interact with that geometry is going to be different for different people. Fantastic. Well, we know that talking about foot strike pattern is one that can be a bit contentious just because of, you know, longly held beliefs about this stuff. And we would love to hear other people's opinions about what they've learned about foot strike. And just because the evidence doesn't say this truth for everybody, it doesn't mean that there's not going to be really amazing stories of someone switching their foot strike and it really changing their experiences. A runner like those things are going to happen. And so we don't want to devalue or make those invalid either. But if you have things that you want to contribute to the conversation, we invite you to do so. You can comment below. We're all just trying to learn alongside one another in these kinds of spaces. Before we sign off, either of you have anything else that you want to add about foot strike or shoes that you specifically think are good for a certain foot strike pattern. More long lines of caution of hey, if you're doing okay, this is not a priority of something that's going to keep you injury free. There's a lot of other things out there. And also be aware when we talk about foot strike, we're only talking about like the foot, you're forgetting about the knee, the hip. And there's other, there's a lot of different movements that go into running. It is so much more than how you're landing. And how your foot is landing, how your foot's position when you're landing. And I am a little bit more of the belief that it's very multifactorial, but a lot of how your foot gets set up to land is very much affected by what's happening up higher, not necessarily the other way around. So just because again, swing phase, a lot of that's coming from hip and knee. And what happens there is also going to set you up, not to poop it, but just saying if you're looking for things that are improve your performance, improve like injury reduction, those are going to be things like adequate street sleep, stress management, eating enough, training smart, recovering appropriately between training sessions, not over-training. Those strength training, improving tissue resiliency, those are the things that are either going to reduce injury risk, or the patients that we talked about with Josh Kerr to go just the time of putting in healthy, consistent training over long periods. That's what's going to get you faster, not necessarily some small change. But if you are that person that you find that loading differently is really the only thing you got that keeps you going, that's great. That's fine. I'm not here to poop it just saying. If the big things you really want to focus on, for most people, this isn't it. David, you have anything you want to add? I think that was good. Perfect. Well, thank you everybody for joining us. If you want to join in on the conversation, you can always follow us on YouTube and join in the comment section, or you can email us at [email protected] and we look forward to continuing the conversation.