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Expand your running knowledge, identify running misconceptions and become a faster, healthier, SMARTER runner. Let Brodie Sharpe become your new running guide as he teaches you powerful injury insights from his many years as a physiotherapist while also interviewing the best running gurus in the world. This is ideal for injured runners & runners looking for injury prevention and elevated performance. So, take full advantage by starting at season 1 where Brodie teaches you THE TOP PRINCIPLES TO OVERCOME ANY RUNNING INJURY and let’s begin your run smarter journey.
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On today's rerun, Predicting Future Injuries and Early Detection with Eric Hegadis. Welcome to the only podcast delivering and deciphering the latest running research to help you run smarter. My name is Brody. I'm an online physiotherapist treating runners all over the world, but I'm also an advert runner who just like you have been through vicious injury cycles and when searching for answers, struggled to decipher between common run... myths and real evidence-based guidance. But this podcast is changing that. So join me as a run smarter scholar and raise your running IQ so we can break through the injury cycles and achieve running feats you never thought possible. Eric Hegadis is quickly turning into a very good friend of the podcast. He is a professor, a physical therapist, clinician, scientist and researcher. Last time he was on the podcast was episode 186. The title of the podcast was a comprehensive look at return to running. When we looked at his uh clinical commentary publication that he released in last year, 2021 and talked about training impulse when cross training and overall training volumes, very, very knowledgeable. We just went back and forth talking about a whole bunch of concepts. Um, very like-minded, which I try and get people who voice different type of opinions, but Eric is so well educated on his field and I follow a lot of his work. And so we kind of come to the same conclusions cause I agree with everything that he releases. So today is looking at. injury prediction. And even just last time he was on the podcast, said, Oh, when you want to have me back on, let's talk about predicting injury. And I thought it's a fantastic idea. And he sent me a few publications. The paper that we're going to discuss today is about physical performance tests. And if we can do any physical performance tests to predict injury or increase the correlation of future injury, those types of things, we delve into it like We were just bouncing back and forth with ideas and concepts. And even after the recording, we just kept talking for another 15 minutes or so about injuries. And, uh, he can tell he is super passionate, just as passionate as I am about these particular topics and trying to reach runners and try and dispel a lot of misconceptions and try and disseminate a lot of research because it can be really convoluted, really confusing and just trying to. Decipher and put in a clear message that runners can understand. He's right on board with that. Always love talking to him. He'll definitely be on the podcast again. And let's dive into round two. Eric Hagedes, welcome back to the Run Smarter podcast. Thanks for joining me. Oh, my pleasure to be back. I'm honored to be a repeat offender, so to speak. We had a very nice conversation us back and forth last time you were on. So, uh, looking forward to today, your paper. Let me, I've got the title here. Physical performance tests predict injury in national collegiate athletic association athletes, a three season, a three season prospective cohort study. Um, we've already, I'll probably put in the intro, uh, your credentials because we've already heard it on the first episode that you're on episode 186. I have down here. The title was a comprehensive look at return to running. So people are already familiar with you. So let's dive in. What was the idea and the aim behind this paper in particular? Well, so when I thought about doing this paper, there was a screening tool called the functional movement screen, is well known worldwide, but which everyone was accepting at face value. So in other words, if you get a certain score on this, you're going to get injured. And if you don't, you know, if you do better than that certain score, you're not going to get injured. And I thought that was, that life is rarely that simple. And so what I wanted to do was investigate these physical performance tests. And physical performance tests are just do a deep squat for me, do a one-legged deep squat for me, do a... a plank and see how long you can hold it. Those are physical performance tests. And I wanted to see, and the FMS is composed of physical performance tests. So I wanted to challenge that thought process. And what I really thought I was going to find was that those tests were absolutely worthless, but that's why you do the research because it turns out they weren't worthless. Okay. Yeah. And so you're, you're hoping to find or test out the available screening tools that you had, or did you want to try a screening tool method that was different from the conventional? I wanted to start from scratch because as any good scientist does, there was a lot of literature coming around at that time challenging the original assumptions of the FMS, that being that it actually predicted injury because the only study that said it predicted injury at that time was a study done by the authors of the FMS tool. So it's not an unbiased study. It doesn't mean they did anything untoward. It just means it's not an unbiased study when you've developed a tool. So I really just started from scratch again by saying, OK, let me do a systematic review. And by the way, after I started doing the systematic review, I thought, boy, let's make a PhD out of this. And so I did. But I started doing the systematic review. of every special test that was out there for the lower extremity, hip, knee, foot, ankle, to see do we have any information about any of them being associated with injury. And what I found out was there was one test in one study that said it sort of kind of was associated with injury. So then it gave me license to be creative. So what I did was meet with track and field coaches, um lacrosse coaches, um strength and conditioning coaches, exercise physiologists. And I said, what tests do you think important? What constructs do we want to be able to capture? And we can talk about what constructs are, but what basically what things do you want to capture like flexibility that you think are important? uh so we created a list of them. piloted that list and then got down to a group we thought we could test. How many tests did you end up coming up with in the end? Let's see, I want to say there were probably 15 tests at the end, because we couldn't, you know, with no guidance from the literature, we were guessing and we didn't want to leave anything out that was important. And the athletes that you decided to put these tests through, they were just all collegiate athletes across the spectrum. So track and field sports, uh everything like that. They were no American football players, soccer players, you know, as we call football in the U S uh basketball players, male and female, and about half of them were distance athletes. So that's both a strength and a weakness, right? uh You have to be careful about applying this to every athlete. And it might have been better in retrospect to get only distance athletes than I could have made firm conclusions about athletes. But the strength of it is we had some positive findings with overuse injury in a group of athletes across the spectrum. A large portion of those were running athletes. So it became very appropriate to generalize the findings to distance athletes, to runners. All right. And so how many people did you end up recruiting? And like, was, how was the study designed? So for three years, um, in the pre-season, and this was conventional methodology at the time. And toward the end here, I'm sure we'll get talking about why this isn't good methodology now. And it sounds like, oh, well, how long ago did you do this? This was like, 2012 through 2015. So that's already too long ago. know what I mean? Things just progressed rapidly. so at that time what we did was test every athlete in the preseason and track their injuries all season long. At the end of each season we would correlate our results of our tests with who got injured and who didn't get injured. Okay. And while I was having a look at the paper, it seemed like all of the tests, all of these physical functional performance tests that you put in there were kind of grouped into sort of subcategories. had the active motion, you had power, you had hip stability, you had flexibility, and then you had motion control. And it's nice that you do kind of put them into these pockets. I think, you know, people kind of get flexibility, but for things like active motion, what sort of tests like, what would you, what do you mean when we categorize them into to active motion tests? yeah, that's great question. so active motion was we did an inline lunge. That's just standing with your foot on a starting line and lunging forward as far as you can. And we would measure how far people could lunge. And then we would compare that to the other leg. So there was some symmetry testing involved there. And the other thing in active motion was a lateral lunge. So what we were really testing is sort of your real life hip mobility in essence. Okay. um Hip stability. Would it just be like single leg functional sort of testing and seeing what the control is like through the hips? Yeah, no, that's also a great question. That's actually the motor control group when you do a full squat and a single leg squat to see how pure your movement is there. So in other words, do you have enough strength to keep your leg in a relative line as you do a single leg squat? That relative line means the knee is lined up with the ankle. You know, you're not deviating one way the other. And we would also look at when we ask you to do a single leg or a double leg squat, did you have the strength and mobility to complete that task or did you simply bend forward at the waist, which is a compensatory motion if you don't have good hip mobility. So that was sort of the motor control group. Hip stability was side plank hip abduction, so leg scissoring away from center. and then side plank hip adduction, was leg propped up on a chair and the leg was scissoring toward the center. So they were just really a side plank exercise with some hip motion, so it was a measure of hip strength or hip stability. Okay. So a lot of this is kind of looking for asymmetry and in your motion, in your, your range kind of activities, flexibility, we can kind of get power. that just looking at a single performance like jumping or landing or, um, just over like one or a couple of repetitions? It was yes, exactly correct. It was a triple hop and a vertical jump. Those were the things that were measured to get that power construct, that ability to move. quickly and strongly. When I'm looking at these sort of tests, um because what I do with my athletes is say how much can they squat compared to their body weight or how much can they do a knee extension or a hamstring curl compared to their percentage of their body weight or those particular things then compared to the other side where they're really pushing themselves to kind of physical limits or to capacity or... um endurance, challenging that endurance. Was there anything like that? Any sort of tests involved in, these? Yeah, no, we, we, um, we stuck to body weight, uh, tests because, uh, we thought if these are going to be useful, the average field side or court side coach without access to a weight room, perhaps. just wanted to be able to screen athletes and see did we feel like they were going to be injured or did they need to get on a preseason lifting and movement program or not. And so these were all body weight exercises that we tested with our athletes. Once again, just to see if any coach in the world could do them, whether they were in middle school or elementary school, were they actually useful to those coaches or should we not tell them to be doing those things? Hmm. So very easy to administer and very like if you had, if you somehow found some findings that were linked to injury, it could be very easy to test and, um, And, and test large groups of people. So, so, so if you're a coach and you have a team of 45 athletes or 65 athletes, sometimes like track and field has, can you test all 65 in a day? and so the efficiency of them was the strength of them. But doing what you were doing by having them do like sort of maybe one repetition max and those sorts of things. Um, a good way to go also, we just didn't think every coach had that field side or court side. Yeah. And then the athlete itself would need to be very proficient with those particular movements. You'd need to have like, you can't test a one, one rep max squat for everyone. Cause you know, that's going to be very dangerous for someone to do it unless they're very experienced in the gym. So you want to consider their safety as well. And in the study, you mentioned that you combined the findings of their tests with known risk factors, um, which being age, BMI, gender, um, excessive flexibility and their past history of injury. So you, can you explain exactly how that process works? Like the, are you combining all of those tests and then sort of correlating with other things that you know that might be linked to injury and seeing what the results show? Sure, sure. And this is very traditional methodology and I won't bore the listeners, but in essence, you test each of those factors, each of the new factors that we develop by themselves, but then you want to see on a grander scale, do they actually add anything to what we already know about injury? So in other words, they're There are the one constant about what causes injury is that you had an injury in the past. So if you've had one, you're going to get another one. And same with surgery. If you've had surgery, you're going to get another surgery and you're going to get another injury after that surgery. There's pretty good data to support those things. But there's also some studies that said sometimes gender is a factor, sometimes age is a factor, sometimes body mass index is a factor, and sometimes being hypermobile was a factor, not all the time, but we wanted to take those established sorts of things that were correlated with injury and see if we added our new variables and stuck them in the same formula. Did any of the new variables matter at all or was it actually adding nothing to the literature? So in other words, could you just stick with past injury and age and gender and hypermobility and body mass index and say, yeah, the field test the performance tests don't add anything. So that's a very important step to take in the methodology is make sure that they matter at all on the grand scale of things. And so it turned out that they did, which was surprising. Yeah. Let's dive into the results before just quickly. uh How many uh athletes did end up being included within this study? So how big was that sample size? And yeah, let's delve into the results. So 360 athletes tested over three years. So uh it's a fairly sizable study. em Could you argue that maybe we should have tested thousands of athletes? Yeah, maybe. But that would have taken a lot longer than I had for a PhD, quite frankly. But we thought that was a fairly good sample size. Your time is valuable, Eric. Yes, yes, that's right. so spending six years getting a PhD with a wife and two young kids was not negotiable for me. uh And so then we did the analysis three different ways because a lot of studies have shown that your results depend on how you define injury. So in other words, some people say, well, I'll give a very easy example. A lot of runners get pain after they run or compete. Many of them go out the next day and run. So they haven't missed training and they've been able to compete, but they are in pain. So is that an injury or not an injury? Or is it only an injury if you miss an event or miss training? Or is getting the flu because you've over trained an injury or not an injury? Is the illness count in that? So what we did was say, okay, we're going to injury in the largest sense, we're going to do the analysis with that as the final outcome. We're going to do the second analysis with traumatic injury. So that would be a collision or a fall or, and for those of you who are distance athletes, you'll be thinking, well, I don't really ever collide with anything, but you can go running on a trail. and get an ankle sprain because you stepped on a root or stepped in a hole that you didn't see or hurt the bottom of your foot because you stepped on a rock. We called that a traumatic injury. And then the other ones were the non-traumatic or the overuse injuries. And for the running population, since that's the most common one, that was of special interest to us. Absolutely. And so what did, once you combine all these known risk factors and these physical performance tests in pre-season, what did the results come to? Well, so the results were um good and exciting, but then all of sudden they got super exciting because remember I said that the one thing that we know about injury is if you've had one previously, you're going to get one again. We were certain of that from the literature. More than one study in lots of athletes in more than one sport have said if you've had an injury in the past, you're going to have another injury. Well, when we looked at non-traumatic injuries and included the variable of motor control, so this is your ability to move well in a single leg squat and double leg squat. the previous injury disappeared as a factor that was associated with injury. So that's a big deal because what it means is when we say previous injury is associated with getting injured again, we don't know why that is. So is it because you didn't rehab well enough and that's why you got injured again? Did you permanently damage a tissue that never recovers and that's why you get injured again? Are you psychologically affected by that injury? so that you move differently and that's why you're injured again. We really don't know why past injury predicts a future injury. But the interesting thing was, is it became a non-factor in these overuse injuries when motor control was studied. So I thought that such a simple test to eliminate past injury was a rather remarkable finding. Yeah. Anything else? other of those very exciting findings? Well, so there was another, there were some other correlations with, with injury in general, but I, I'm not sure if I, if I trust those findings, um, cause active motion and hip stability were associated with injury in general. When we talk about injury in general, we're talking about overuse injuries and collision injuries or traumatic injuries, right? So the assumption there would then be that if you have bad active motion and poor hip stability, that you're going to run into a player on a field six months from now and get injured. And I don't think that's a very realistic conclusion. think this, so I think it was a an incidental finding. I was more excited about overuse injuries because of our cohort, which was mostly runners. Um, and, and, the fact that a simple test is something that you might want to use as a tool to say, well, how are they moving? Maybe that's important. Hmm. And so if someone scored quite low in these motion, the motor control tests. So you're looking at double leg squat and you're looking at single leg squat and how effective they are moving through that movement. It didn't matter whether you were injured in the past or how many times you've been injured in the past, the people that had that poor control, poor motor control got injured at the same rate. Is that right? They were more likely to get injured actually. Okay. Yeah. Right. More likely to get injured if they. Scored poorly. Yeah, it didn't matter whether they had injury or didn't have injury. So whether or not they had an injury became, became unimportant. Yeah. It became irrelevant because their, because their motor control was so poor that that was the overwhelming factor. Okay. And since we're now honing in on this particular finding, we maybe go into a bit more detail about the squat, about the double leg and single leg squat for the motor control? So you said it was body weight. Exactly what particular movements or what qualities were you looking for that described where they scored high or scored low on that test? Yeah. So this is great. If you have people out there who want to test themselves in front of a mirror or coaches out there that want to test their athletes, we use a very qualitative method of qualitative in the sense that it wasn't a specific number that had you score good or bad. um What had you score good or bad was your quality of movement. So in other words, we would have people for the double leg squat, we would have them stand, feet shoulder width apart and hands right up over their head like they're signaling goal or American football touchdown. So parallel arms straight overhead. then we would have them squat and we would see, could they keep good lower extremity alignment or did their knees either go outward or inward. Most often the fault was the knees came to the midline. So the knees would start to come together in the middle and touch almost. um There's a couple of reasons for that. As somebody working with athletes, your next step after that screen would be to investigate why that is. You can have poor ankle mobility and that can cause you to move poorly or you can have poor hip strength and that can cause you to move poorly. Or you can just have had an injury in the past and your body has forgotten how to coordinate all the segments of the lower extremity as it moves at the same time. And so it can be any one of those causes and your job is to investigate further. My job as a physiotherapist is to investigate further to see why it is that your movement quality is poor. So that was the double leg squat. The other thing you could do wrong in the double leg squat is We would see people who actually would bend very little at the ankles and the knees, but would simply flex their spine forward in an attempt to get lower. We also saw that as a fault, a poor movement strategy. That was generally people who were not very mobile. um The single leg squat was actually very similar except the hard part about the single leg squat is many people who did well with both legs on the floor when you ask them to stand on one leg and do the same test, arms above the head parallel, standing on one leg watching for all those substitution patterns, many of them who did the double leg squat well fell apart when they did single leg squat. Their movement pattern was very poor. They didn't have the strength stability coordination in one leg bearing the whole body weight. And I'm guessing the, the arms need to stay like fingers pointing towards the ceiling the entire time. could imagine a lot of people squat and their, their arms just come down. They could probably try and get a little bit more movement in their squat. If their arms came down. Yes. I could imagine that would be quite a, a sort of compensation sort of movement as well. Is there, was there kind of like a. A pass rate for how low they needed to squat. Did they need to go to like, did thighs need to reach parallel to the floor or any sort of benchmarks? question. They had to get thighs parallel to the floor if they could. And many could not get anywhere near that. I mean, I definitely couldn't now. Maybe, maybe back in the day, but not now. I'll have to give it a try. And this comes back to, with choosing the body weight exercises like all the listeners could try this as well. They don't need any equipment and they don't need any specific. Yeah. A mirror or a video camera that they can look at later. The other thing you want to look at is the, which we saw was When the knee comes to the midline, the upper body has to rotate toward the knee that's collapsing. That was a very interesting thing. Let me say that again. When you don't have enough motor control or strength and your knee sort of buckles toward the midline, so towards the other leg, there is a compensatory rotation of the trunk toward that buckling knee. When your hands are above your head in parallel, you can actually see the entire body rotate and the arms move so that they're no longer parallel. And then we would go, oh, okay, this was a real subtle sort of knee thing that happened, but wow, look at the rotation of the arms above the head. And so these are, again, easy things for you to do looking in a mirror. videotaping yourself. Yeah. And so feet needed to be shoulder width apart and the toes needed to be facing completely straight. couldn't be turned out. They could be turned out slightly, but not, not a lot. It was okay if they were straight or slightly turned out less, maybe 10 degrees or less turned out. would allow that. Okay. Wow. So what do you, what, what conclusions can you draw? Like if people are poor in these tests and they getting injured or more increase in their likelihood of developing an injury, an overuse injury in the future. conclusions can you draw? What sort of, what do you suspect's happening with the runner with a poor control that's like, why are they getting injured? I guess is a better answer. Oh yeah. So, so I can just tell you from, from 31 years as a physiotherapist, right? What, what do I see in these people who move poorly? Uh, probably the number one, thing I see in distance runners is gluteus medius weakness. So that if you stood on one leg and lifted your leg straight out to the side, that's what the gluteus medius does. It does hip abduction. But the thing is when you're standing on that leg, it is the job of the gluteus medius to keep that knee from buckling to the midline. So what we would see is either poor strength or poor motor control. I can tell you in runners, there's two kind of major muscle groups at the hip. One extends the hip and distance runners were amazingly strong at that. Amazingly strong. So their gluteus maximus, the big muscle that you see that your rear end. Very strong there. And then the gluteus medus was phenomenally weak. And that's because when you do a sport, if you're not careful, When you do a sport where the sole direction is running straight ahead, you develop the gluteus maximus and the gluteus medius is more active when you're cutting or changing direction. Or in a runner, you have to be very diligent about making sure that you strengthen that. And that gives the pelvis stability and gives the knee stability. So that's the number one thing is that gluteus medius weakness. The other thing that I saw is a lack of ankle mobility. When you talk to them they say, oh yeah, I've sprained my ankle several times on a run. uh If you run out of the ability to flex your ankle during a squat, ah and the easy way to test this by the way is if you put a board underneath your heels and all of sudden your squat gets better, it's because you have poor ankle mobility. If you run out of room in your ankle, happens is you pronate your foot, which basically means collapse your arch. When you collapse your arch, your knee also collapses to the midline. In other words, when you look at the knee, it's either a distal cause, ankle mobility, or its approximate cause, or poor motor control based on gluteus medius. That's what I saw most of the time, 90 % of the time. Yeah. And I was trying to look up just as you're answering that there's some work from Chris Brammer in terms of, uh, he observed a lot of contralateral hip drop in runners or in injured runners and found that that was a significant, um, finding when it came to, I think he said every one degree of contralateral hip drop was a, a link to like three times risk of injury. I'll have to look it up, um seems to be very similar to what you're finding in this particular study. Yes. Yeah. think, I think we're, I mean, certainly from uh contact sports and cutting sports, right? There is, there is, to be a strong relationship between that knee buckling to the midline and injury. Um, and you can, you can test it with, what we learned to do is test it with ever increasing difficulty. So this is after the study. Because what we would see is, someone who does well with a single leg squat, we would push them to the next level and we would say, okay, do a straight ahead hop test. And many of them would fail that test. But if they were good at straight ahead hop tests, we would have them do a medial hop test. And then very often athletes who did great at double leg, great at single leg, great at a straight forward hop as soon as we had them hop in a different direction. So immediately their entire knee would buckle to the midline and you knew they were, they were still not at high speed dynamic movement. They still did not have the strength and stability that they needed to move well. And of course running is a high speed dynamic skill. Uh, it's not a slow motion activity. Yeah. I just pulled up that, that Chris Brammer paper now. And the title was, there pathological gait associated with the common soft tissue injury running injuries? And it said like, importantly, every 1 % increase in pelvic drop, there was an 80 % increase in the odds of being classified as injured. So they had injured runners run pain free on a treadmill and, um, witness those sorts of things. And the same thing, contra-lateral hip drop. said that there was a, um I think the knees, like the internal rotation of the The FEMA or internal rotation of the knees, like those sort of characteristics. Um, so yeah, it's always nice to sort of find other publications as well that I guess match, uh, your findings just to help with, I guess, the confidence. And I guess the theory out there. Um, no, you mentioned a little bit, I'm sorry to interrupt you, but that goes back what we said at the beginning, right? When you say the FMS in the beginning was a uh prediction of injury. Well, you want to have more than your group do the study, right? If because then people doubt your results, but if multiple groups are finding this the chances of it being a correct finding a non-errant money or good. So sorry to interrupt you. Please continue. I was just going to mention like you it's important to highlight limitations with studies as well. And every publication, every study has them. Um, can you identify any major sort of limitations with this particular study that we might need to be aware of? Yeah, sure. I mean, again, 2012 is a long time ago now, right? So think of where we have come with wearable sensors. There are watches you wear on your wrist now that are more sophisticated than biomechanics labs 10 years ago. And so the major weakness of this was the studied design, which is anytime you test an athlete in the preseason, and you wait an entire season and again for us our distance athletes were in season year round. I mean they went from indoor to outdoor to cross country seasons. So they're the only athletes, our distance athletes were the only ones who never had an off season. When you wait that long for an injury to happen You really can't use the word predict. You can't say that a poor test predicted injury. You can only say that a poor test was associated with injury three months, six months, one year later. So that's a weakness in the study. uh Prediction of injury has come a long way and maybe we'll talk about that a little bit. already, like within five years, I knew I would do a different screen with people. So not necessarily a prediction, but just a preseason correlation would be better defined. Yes. It's not, um, it's not as strong a word on purpose. Uh, it just means that people who got injured scored poorly. doesn't mean that the fact that you scored poorly predicted you were going to get injured. That's a pretty bold statement. When you look at all that happens to an athlete. I mean, think. Think, especially in a college athlete, of all the things that change in six months or a year, right? You're under lots of stress. Your parents break up. Your girlfriend or boyfriend breaks up with you. You're overtraining and you get another injury. So there's so many things that happen during that time. It's just not a very strong statement to stay to say correlated with. All learning is a journey. I'm already down a different path with a great colleague of mine, Ben Stern, and some others about, can we really predict injury? Now we're working on actual prediction. Right, looking forward to hearing some developments in that area. I had here particular like study takeaways or like practical lessons takeaways the runners could um get from this particular paper. Obviously that finding the tests themselves that the double leg single leg squat looking at the quality is a really nice um takeaway for someone to do. Is there anything else that you? maybe want to highlight to the runners or maybe get them to take away from this these findings? Sure. Yeah. And I'm going to give you takeaways, not only from this study, but then takeaways of, you know, the continued journey of discovery. So what have I learned since 2012, which is a lot, right? Because I'm in the business of trying to learn more so that I can help runners in a better fashion. em So number one, The way you move matters. So you should look at how you move and it's simple to look at yourself in a mirror. Or you can get more sophisticated help by going to uh somebody who understands biomechanics or physiotherapist who understands biomechanics and have your movement analyzed. uh Number two, physical oh isn't the only thing that matters. There's a whole range of psychological um variables that probably are associated, not probably, they are associated with whether you get injured. in other words, um if you are feeling, and this is really about paying attention to yourself and paying attention to your body, be alert, be aware. Because I think we get as runners, you're so used to pain. Because very often when you're training and you're pushing yourself hard, the training is actually painful because you're bound to push yourself. The cardiovascular system is straining because that's what you're doing on purpose. But you do have to pay attention to things like if you are feeling chronically fatigued, you are headed down the path to injury. You're more likely to be injured. If you are feeling stressed, more stressed than usual if you are feeling like your sleep quality is starting to deteriorate. Whether because you're over training or because, hey look, you've been to a, this is my son recently, like for a while there all the kids his age were getting married, so like six weekends in a row, uh they're going to somebody's party for their wedding and kind of, you know, tearing the roof off. Right? then, so too much alcohol, not enough sleep, out too late, you're greater risk for injury if your sleep quality is poor, if your nutrition is bad, if you are noticing great muscle soreness. It is not a weakness to say this is going to be an easy day when you're experiencing all of those things. Plus, you have the addition of the things you wear on your wrist that tell you how did you sleep, what's your heart rate, what's your resting heart rate, what's your hydration level. So there's lots of items out there. Granted the accuracy of them is still improving, but they are still good enough if you are paying attention to say, wow, so my energy level is lower, feel more fatigued. I'm definitely more stressed in my life or because of work. My sleep quality is suffering and I'm super sore after training lately. That should be, that should set off an alarm bell that you need to back down a little bit in your training. Not because you're weak or not because you're not mentally strong enough but because your system is very vulnerable at that time. And so you do not push yourself to your maximum workout when your system is vulnerable. That's how you get injured. I have this, uh, tight rope walker analogy that I'll share with you after this recording, cause people have listened to episodes on that, but I wanted to get your thoughts on your, number one thing that you said there is the way you move matters. And there are some, there are some theories out there that movement doesn't really matter because your body would just get used to it if you train properly. Like if you, if you just don't have any abrupt changes in training, you can have a narrow step width or you could have a internal rotation or you could have a mild hip drop here and there. And if you train within the right parameters and you allow your body to adapt to that, the body would just get used to running in that particular way. And I kind of had a theory is yes, that is true, but gives you very little wiggle room for training changes, like for load changes. You could probably get away with it, but you have to be super careful if you elicit a few of those particular movement patterns and behaviors. But I want to get your particular thoughts around that idea and whether you're thinking something different. no, I could not agree with your theory more. Um, I, so. you know, as somebody who does research, we always talk about, here's the value, whatever that value is, and here's the confidence interval around that. So, I think your theory is dead on. I have a similar theory in that um we have seen, I have seen some people win the New York Marathon whose movement, I thought, was rather abysmal. um That's testament to some other things. You can't discard genetics uh as a thing that contributes to your ability to compete and win. em As well as your belief in yourself. So there's all these psychosocial variables too, em Your body will be that person who moves that way, I believe has a very narrow confidence interval and it is not difficult to push them from a healthy body state into a body state that probably means they're going to get injured. Whereas someone who moves well, that confidence interval is a little larger. You can get away with more perhaps. That's what I think. Yeah, I think we're on the same wavelength there. um I want to ask like just straight up nice and simple as a question. Can we predict injury? Uh, based on your research, based on everything you found, how strong or how confidently can you answer this particular question when it comes to running related injuries? Can we do some things or can we have confidence with predicting injuries? Yes. What a great question. ah Do I believe we can predict running injuries? Yes. Do I believe that technology is allowing us to get closer and closer to say more certain things? Yes. If you ask me today as we sit here on your podcast talking about when I look at you how confident and I gather all this data about muscle soreness and stress and fatigue and all that stuff, how confident am I that you're going to get injured based on the data that I'm gathering. 30 to 50%. Okay. That's pretty good. um better than what definitely better than what we've had in the past. And so it seems like you need more data. You need more accurate data and you need to explore a whole bunch of different, like you said, psychosocial recovery, training loads, um, behavior mechanics, thoughts, um, all those domains. in order to compile it all together to get that level of prediction. Yes, you are dead on and that's the take home message and that's what researchers are working on right now because as you might guess, there are billions of dollars tied up in being able to predict injury, right? If you knew that the greatest runner in the world who is about to run the marathon might get injured this weekend, but next weekend would be able to run better with less chance of injury. might say, look, I know that the Boston Marathon is an important showcase, but you shouldn't run it. And uh what a valuable piece of information. And now change that to What are the big money sports in the world, So soccer or football, American football, rugby. And if you can start telling those coaches, you need to sit your star player this weekend because they're more likely to be injured. As you might guess, there's billions of dollars. we have been waiting for technology to catch up. For what I said in the beginning was the design was flawed. You can't do a test and then wait six months and then and then draw anything more than a loose correlation. What is important though is if you collect real-time data and lots of it, you can analyze that data to be better at predicting. Your listeners will go, a uh very common example of that is if we get uh hurricanes all the time here in the States that come off the eastern seaboard. If you look at how complex of a model that is, it is very difficult to predict where in the United States those things are going to hit a week from now. But when you collect lots and lots and lots of real-time data, you're almost certain where it's going to hit within 24 hours. And so that's the value of those things you wear on your wrist, those data collectors that you have, and then paying attention to them. Yeah. And in terms of like takeaway lessons for the listeners, I think when you talk about all these multitudes, this multifactorial approach to injury prevention and predicting future injury, if it all seems a little bit too overwhelming, um I think some practical takeaways would be, okay, let's focus on some main components, that being like training loads and abrupt changes in training. Uh, but once you've kind of nailed that in, that's not too overwhelming. Then you can move to the next thing, which might be depending on your mileage might be adequate recovery. So sleep, nutrition, hydration, um, stress levels and analyzing that. then once you're kind of comfortable with that and you, you, you've got your head around it, then maybe moving to the next domain, which might be strength training or making sure your hip has good control, mobility, uh, running technique, those sorts of things. And then just moving on. so you're, you're taking in little chunks at a time instead of being so overwhelming that you just go out and train really nearly without any care in the world. Yeah. I think you're dead on. I think that's why you have a coach who can say, this is what we're going to focus on. know, runners almost more than any other sport are really good at cataloging things. I did this investment run on this day and this was my time per mile or per kilometer. Right. And so runners are. excel at that. what you need to start doing then is paying attention to not only mileage and distance and how fast you ran that distance, but if you're suffering from anxiety and depression and you haven't had that treated, that's a factor in whether you get injured or not. And so you have to take care of that. So the athlete Looking at yourself as a whole human being and not a runner is probably pretty important. It's more than just physical variables, although they're important. There are a bunch of other ones that I think a good coach, someone like yourself who is working with somebody can say, Yeah, let's look at this injury that you got here recently and let's examine some of these things a couple of weeks before. Where were you mentally? How sore were you? How fatigued were you? Was your sleep level good? And what you'll find out is they'll say things like, oh, you know what? I had business in the States and so I flew across several time zones, barely got adjusted there, flew back home. eight airplane food. so, you know, and, and all of a sudden something that you just assumed was an unobserved part of your life became very important and why you got injured. Uh, and that awareness is very important for your group to start thinking about all those things. Awareness definitely, because we do encounter those moments in life. If you're traveling, moving house, um, you have like, family dramas, all that stress of work, promotions, you know, you need to look at yourself as a whole and not just analyze purely the running components. So very good to point out. I did want to flip the focus slightly and see if we're talking about injury prediction or injury prevention. Is there any early signs that a runner could pay attention to that might lead to an injury if unaccounted for or ignored? Um, just wanted to get your thoughts on if there were any particular early signs of injury and what you can impart on the listeners. Yeah. So this, so this is early, early data, but we sort of think that when you combine things like fatigue, stress, sleep quality, and muscle soreness, if you examine those four things very closely and all of those are bad, Uh, an injury is coming for you. You said fatigue, sleep quality, muscle soreness. Um, and, um, so fatigue, stress, sleep quality, muscle soreness level of stress in your life. those things, and you'll notice that. A couple of them are psychosocial. couple of them have to do with your physical feeling. Um, so yeah, those, those tend to be the ones that you can monitor pretty easily. And if those are off, you are headed down a path where you're more likely to get injured. I'm definitely seeing the muscle soreness and the fatigue side of things definitely changes your running mechanics as well. Like your. hitting the ground slightly harder and your stance time is slightly, um, slightly longer as well. You just like, you're slapping the ground and a little bit less efficient, which like significantly spikes your training loads as well. And that's just looking at the pure ground reaction force side of things. It's not even looking at your ability to recover or handle tissue loads. Once the running is done, once your body gets into that recovery mode and can effectively sort of negotiate that, but ah Definitely. And I've seen people recovering from injury. If, ah if they avoid running fatigued, they can manage loads quite a lot more. They can, if they integrate some like walking intervals within their running and they're avoiding that fatigued kind of onset, like they're the onset of their symptoms come on either a lot later or not at all, or, you know, less severe. so Even just that aspect alone, I'm seeing a big difference with the runners I'm working with. Um, but yeah, then you're looking at sleep quality and stress. I've got so many podcast episodes on the importance of stress management and recovery, uh, and sleep for recovery. so if someone is, if someone's say falling short on these, if they are getting muscle sores, they are feeling fatigued, their sleep's not great or their stress management's, um, not up to scratch as what they're used to. What do you recommend? What should they do? Are they backing off their training loads in these particular, until these areas are built back up? uh Yes, they should back off their training loads until these areas come back into normal for them, wherever that happens to be. And, you know, we don't know what normal is for lots of people. have, I have friends and a father-in-law who's normal throughout his life is to sleep four hours a night. um I have a daughter who needs 10 hours of sleep a night. If I sleep more than eight, I feel worse, but eight hours seems to be my magic number. I think you need to be wise about your training, which is what is the goal of that? What is the goal ultimately of running? I would say yes to compete, but for many of your non-competitive folks, it is to be healthier and happier. So if you're out there pushing yourself every day even though you're exhausted and your muscles are sore, you can't tell me you're enjoying running. You've taken away the joy of it and you're ignoring it because of some attachment to, I don't know what, some attachment to you have to be tough and you have to endure or it's not. And I would tell you if you are somebody who feels like They train well and then they get injured. Then they train well and then they get injured. This is happening to you where you're getting injured two, three, four times a year. You're probably not paying attention to those non-training variables. You're probably playing very close attention to load and how fast you're doing things and how far you're running, but you're probably not aware at all or in touch with your human system and how it feels and whether you're sleeping well and whether you're stressed and whether you're happy or not happy. I mean, I will always tell my runners and they look at me like I'm crazy sometimes, but that's okay because I'm of an age where I might be. uh I will ask them, it's the last time you smiled when you were running. It's the last time you got that euphoric feeling of, man, it's a beautiful day. And I'm fit and I can push my body and I'm running. a magnificent moment to be alive. Right? Does that happen to you? Or do you just go, are you the, are you staring at your watch the whole time? Yeah. Yeah. Yeah. It's so, it's so well put. I'm glad that you talk about that because so many runners, when they're injured, they just want to. They're like, I'd give anything just to be pain free. If I was pain free running whatever distance, I'd love life. I'd be so happy. This is just what I want to achieve. Then they get there and they, they're not really happy. They, they want to push for the next thing. They want to push to the next thing. It's like, yeah, I'm running pain free. said that, but I'm not running like 10 Ks. That's really where I want to be. And then when they get to 10 Ks, it's like, yeah, but I'm really slow with my 10 K. Like I really want to improve that. And it's just like the next thing that we are quite harsh on ourselves sometimes. I think the classic trait of being a runner is the ability to self motivate, push himself, push themselves, have the next goal, the next goal, the next goal. Um, but exactly right. If you're not enjoying the process, what's the point in doing it? You need to be happy and healthy. And if, if that's not achieved, then you, you're just not training with the right purpose, the right method. And if you are getting injured over and over, it might be some sort of self sabotage. you know, training philosophy that you have, maybe just keep going out too hard because you continue to push yourself. And if you were wise about your training, like you say, and you listen to your body and maybe your body's telling you it's time to have a day load week or rest, or maybe we shouldn't go out that hard, but you're just driven and your, your, um, internal circuits are just constantly trained yourself as, like a habit to continue pushing yourself. Um, Maybe it's worth a change. Maybe it's worth reassessing and making that change in not only your training philosophy, but you know how you approach it and the taking that, that happy, healthy approach rather than performance grinding yourself in type of way. Yeah. Amen. Amen. Well said, Eric, is there any other final takeaways or anything else that we haven't discussed yet or final messages for the listeners as we close up? Yeah, I would say only the last thing might be that um You should not look at cross training as a weakness. um There is a reason we see these faulty movement patterns develop in every sport, but in running specifically. um You shouldn't be afraid to take the load off. You shouldn't be afraid um to go play tennis that day. um You should do some things that probably vary the fact that you're running straight ahead all the time. um Or you know your big break from yourself is to swim which is unidirectional Doesn't involve any change of direction except for flipping at one end of the pool and swimming to the other or I hear runners do aqua jogging which is unidirectional So I would I would say it is not a weakness To not go run that day to have fun doing something else that day is probably okay. And to vary your training is probably very good for the way that you will move and you actually probably run better because you move better. said. Eric, I want to thank you for your time and for your knowledge sharing this all out to the podcast listeners. But, um, just as importantly, if not more importantly, thanks for your time commitment to all the research that you do and the dedication that you put to try and come up with the answers that we're desperately trying to seek and you're helping a lot of runners and a lot of athletes in the process. So thank you for all that you do and thanks for coming on today. Thank you. And my pleasure is always, and also thank you because things like research doesn't get disseminated very well. It takes a long time, right? But podcasts actually, we reach far more people than a research publication. So your ability to spread that word impacts, uh, without any without any criticism from me impacts far more people than my research ever would. So thanks for letting me be here to talk about it. It will reach a larger audience because of that. If you are looking for more resources to run Smarter, or you'd like to jump on a free 20 minute injury chat with me, then click on the resources link in the show notes. There you'll find a link to schedule a call, plus free resources like my very popular Injury Prevention 5 Day Course. You'll also find Run Smarter book and ways you can access my ever-growing treasure trove of running research papers. Thanks once again for joining me and well done on prioritising your running wisdom.