Episode 421: Dr. Samuel Spinelli - Hamstring Health & Performance

Dr. Samuel Spinelli is a Doctor of Physical Therapy and Certified Strength and Conditioning Specialist (CSCS). He is the cofounder of Rehab Explained and Citizen Athletics. He has helped many professional athletes rehab and prepare for peak performance. He joined the show to share his insights on hamstring performance and health.

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Episode Transcript:

Thanks again for taking some time to come and chat. Yeah, I've been following you for a long time and like, I really listen to your podcast. And when you were mentioning that you were about your hamstring injury during that, um, attempt, I was like, man, that is so unfortunate. So I thought, whatever I could do to help out, yeah, yeah, I think it'll be a fun chat because I think it's, uh, it's something where like, I mean, historically I've been I had been very injury resistant in general through, like, the majority of my running career. I had some ankle issues a few years back that sort of spiraled into a few other issues. And then, um, I actually had like, I think 18 months of running, like perfectly healthy, no issues or anything like that. Um, although I did have a small case of hamstring tendinopathy earlier last year and it was super manageable. And I, I did kind of a lot of the, the basic things you can maybe correct me if I did the right things or not, but I kind of focused on strengthening versus doing too much stretching and things like that, because it seemed like it was more of a stretching issue versus a like, I heard this by doing too much hamstring strength or something like that. So, um, that seemed to work really well and it wasn't something that really interfered with training at all. It's just something I kind of noticed where I mean, to some degree, when you're training 100 plus miles a week and things like that, there's going to be things that feel a little off here and there that you're kind of managing along the way. And that was just sort of one of them, as far as I could tell. Um, but yeah, then during that event itself that was a full strain. So yeah, I had the bruising and everything to go with it. Uh, so, um, not terrible bruising or anything. I didn't even actually notice it until I went into a physical therapist, and she was like, oh, it looks like there is some light bruising back here. You probably did get a strain there at least. And, um, we worked through some stuff and got things going during the offseason and things like that. But, um, yeah, it's always fun to kind of dive into kind of more, uh, kind of specific categories, like an actual specific muscle and kind of how that plays, plays with everything else when it comes to running and fitness in general. Um, yeah. Absolutely. Agree. Cool. Maybe. Let's just kick things off, actually. Um, sure. Just chatting a bit about your background. Kind of what got you into health, fitness and strength and conditioning and all that sort of stuff. Yeah. Um, well, I was just a pretty standard youth individual, got involved in a lot of different sports, and then I found myself entering into the weight room in my high school and just, like, fell in love with it. And then from there, I just progressively got more and more involved in lifting and health and wellness overall. And then I started to go to, uh, I got a job as a personal trainer, just really interested in it. And during the time where I was being trained on how to become a personal trainer, I was mentored, fortunately, by a really well-known personal trainer slash, um, rehab specialist. And during that time he's like, you know what? You seem like someone who should probably go to university and learn more. And basically that same day, I walked across, uh, down the street from where he was and went and signed up for a university program. And, uh, that got me going. And then I went and got a kinesiology degree. And during that time, I started work as a professional strength conditioning coach and just super fortunate and having a ton of really great mentors who. Took me in with open arms and within. Like my first year of getting involved in this stuff, I was able to start working in professional hockey, helping people from the NHL, the NHL's around the world, and I got to learn a lot. And that spiraled into learning, uh, from a lot of really top end strength conditioning coaches and meeting people from all around the world who are specialists in different areas like baseball performance specialists, hockey performance specialist, football, and then sprinting. And with that, uh, there was a pretty common theme that people would have an injury, and then they'd need to refer out to someone who sometimes wasn't always incredibly knowledgeable about, like the mix of the demands that we'd have. And they were, you know, like a rehab specialist, but there's no in-between. And at least at first. And then I started to learn that there were these people out there who, you know, this was a while ago, so it's become more common. But at the time, there's just a few rare individuals who had this ability to blend rehab and performance and be either the bridge or dual roles. And so there were some famous instances of individuals like Charlie Wingrove and Kelly Stewart, who I'm sure you've heard of. And they were a doctor, physical therapy and a strength conditioning coach. And so I was, again, pretty lucky in being able to contact those people directly, just given some connections I had, and ask them about what their recommendations and guidance was. And they all told me I should go get a doctorate. So I live up here north in Canada and you know, there's not a doctorate program here. So I ended up going to the US and selected a program where I was able to. Go and learn what I need to from that role, but then also engulf myself in further strength conditioning environments. So I ended up going to Boston because it's like a giant hub for strength conditioning. And so then being in there, I was able to go and just bounce around a different high end sports performance facility in the greater New England area and just continue diving into everything. And then during that time, I got really deep into research and was mentored by a handful of people who were, you know, kind of leaders in the evidence based community. And they, again, are very wonderful people to give me guidance on how to develop and better understand research, utilization of research flaws and understandings across different areas, things that might be missed, how to better assess research to then implement. And that really spiraled into me sort of growing an online presence. I know, like we met through Twitter, I don't know if you know, but I have like a very large Instagram following. And then I used to be a part of a company which I have sort of like an NDA with, so I can't speak on it who they were, but they're one of the largest rehab companies. And um, I helped build that YouTube platform as well. So I've. Yeah, ended up becoming well known and regarded for the rehab slash performance space. And then since that time, I've now, you know, worked with a few different performance, um, top end facilities for rehab, strength and conditioning. I've been fortunate to travel and teach, consult with top end people. And then, uh, now I live back in Canada, and I have my own performance and rehab facility here. And then I just. Yeah, keep doing the same thing. Awesome. So with your facility, is that mostly just athletes who come across an injury, or is there a lot of just like, hey, let's make sure that doesn't happen in the first place, that sort of stuff too. So it's probably a big mix of both. We're 2200ft² and we cater to, you know, I live in a bit more remote part of Canada, but we have contracts with all the major universities and colleges in the area for the majority of sports teams. So basketball, soccer, rugby, etc.. And then in addition to that we also coach tons of academies. We also work with general health and wellness people. We have a moderate sized senior community that we work with as well. And then on the flip side, whether I'm more functional in house where if someone has an injury, then I work with them less so than people coming in off the street. But then I also get some interesting cases where people have an injury and they're probably for the majority of the time not located in this area, but they end up flying in and staying here for weeks to months on end and working with me directly and then also with my coaches. And so I've had a few cases, most notably a hamstring injury, um, of individuals who came in to just spend a considerable amount of time with me during either their off season or their actual season because they were injured and out. Mhm. Yeah. Yeah, that's interesting stuff. I know like one thing I want to dive into is just kind of the process with dealing with an I'll call it an angry hamstring, uh, because I think a like a lot of times when people think of stuff that's like, oh, it's hurt, I better leave it alone or not do anything with it. And there's the way I usually describe it is whatever you were doing to get the hamstring issue, you likely need to deviate from that. But going to zero is potentially going to cause you as many problems. Maybe not as many, but it's going to cause some additional problems above and beyond what you would typically want to optimally recover and be back to doing whatever it is you want to do sooner rather than later. Yeah, there's very few instances of almost any injury where complete rest is actually a good thing. You know, like we take the examples of a pretty intensive surgical intervention for an injury, like an ACL rehab or reconstruction. And then the rehab for that is like literally day one. We want them to start performing pretty effortful exercises. And it's consistent with, you know, serious hamstring strains where like, now we've got research that's shown that in the case of the hamstring, we can probably encourage people to do some pretty intensive, challenging exercise on almost day one. And it's likely going to be better as long as it's dosed appropriately than doing nothing. Doing nothing is usually a negative overall, whereas it's more of like finding the right balance of what you were doing. Because in a lot of cases, the poison is also the antidote. And so we need to just find the right scaling for it and then possibly other interventions to support and be adjacent to it. Interesting. Maybe let's start kind of from the basics with hamstrings. So at least on the injury front. Um, actually no. Let's actually go. Let's avoid the injury part. At first, let's assume everyone here is listening healthy and their hamstrings are behaving appropriately. Um, if we're doing that, let's just talk a little bit about how the hamstring actually works. Like how does that actually work with the rest of your body to kind of create that forward propulsion that you're looking for? If you're, say, going for a run or something like that? Yeah. So our hamstrings have a few different functions. So we have three primary hamstring muscles, one of which has two heads. With that they cross the hip and the knee. One of the ones that has the two heads that that one head only crosses the knee, which is an important consideration. So when we're looking at the hamstring it helps with hip extension and knee flexion. And then a consideration with that is when we're talking about hip extension, especially in the context of running is it helps to maintain our upright torso positioning. And this is an important factor, particularly when we get to like the kinematics that might be associated with some running in hamstring injuries. So when we're looking at those factors, you know, the leg comes through. What we call the swing phase brings that foot forward. And as we're about to make contact to the ground, the hamstring is undergoing an eccentric lengthening. So it's getting longer and having some level of contraction. And then it contacts the ground and then it starts to go through a concentric contraction. So it's shortening and helping to bring the body forward over the foot. And so it's this combination of hip extension, possibly some knee flexion and moving the center of mass over that contact of contact to the ground. And along with that, at the same time, it also is working to control and maintain our pelvic positioning, which is something that can be neglected and not considered and is an important aspect because the position of your pelvis can play a important role in the length of your hamstring, which the length of any muscle can impact its force generation abilities, but then also its possible predisposition to an injury. Mhm. That's actually an interesting point, because one of the things I was looking at when I was just kind of diving into the hamstring in general, was some one of the videos I was watching, they were explaining that where like if you do have like an issue where you overextended your hamstring and it is like pelvis related, if you don't fix the pelvis first, you're not really like doing anything. You're not necessarily helping yourself by just strengthening and lengthening the hamstring, because it's getting artificially torqued in a way that it shouldn't to begin with. And if you don't fix that first, you're just kind of putting a Band-Aid on it, potentially. Yeah. So I think that's a really good concept. And I came from a, um, time of being like high level non endurance sports. So I think it's like an interesting juxtaposition to this conversation because, you know, like I spent time getting athletes ready for the NFL combine where their goal is to run the fastest velocity possible and they are cranking out some incredible speeds. And if you look at that, like a regular injury for these individuals is a hamstring strain. And part of it is that they're just, you know, running these insane velocities, which is an injury risk for the hamstring. But a part of that is that a lot of these individuals end up having, you know, like a lot of anterior pelvic tilt and pelvic tilt in and of itself isn't necessarily a problem, but the inability of controlling it and having a. Appropriate balance of it during certain parts of your stride can be a risk factor. And, you know, a lot of these athletes can have some incredibly strong hamstrings, like, you know, um, we have access, like at my facility to this thing called a Nord board, which is from a company called vault, and it's got an inline dynamometer built into it so that when athletes do something called the Nordic, we can measure how much force they create. And we have athletes that are putting out absurd numbers on this, you know, just absolute monsters. But they can have this recurring hamstring injury. And so then from there it's like, okay, well, sure, we can make their hamstring even stronger, but if they keep hurting it, there's something else going on that's clearly part of the problem. In some cases it can be running mechanics. Whether it is the pelvis, it could also be over striding. It could be their forward trunk lean. Some of those ones are like key considerations with possible higher demand on the hamstring. And so yeah like we can strengthen it and do some awesome things for it. But if the person is continuously putting themselves in a position to where they just demand the crap out of their hamstring, it is possibly just not fixing the actual problem. Okay, interesting. I want to kind of rewind, just a pinch there and look at like, let's say we're doing something like that. We have these different types of issues that can occur there. Like you mentioned a hamstring strain. I did as well. But it can get kind of escalated from there. Do you want to just walk us through just kind of like what the difference is between, say like maybe a light hamstring strain and then when you get to like the different grades. Yeah. So overall when we're talking about the hamstring, I'll add a caveat to that or an additional factor. So we've got two main types of quote unquote injuries with the hamstrings. Number one is a strain. And then number two is a tendinopathy which you had mentioned you've dealt with before. And so overall the hamstring is a very long muscle. But it also has these tendons that attach it at either end. And so we can have a muscle strain where it happens to the actual muscular part of the belly. Or we can have a tenderness based injury. And then we can have something where it's also in between where the tendon meets with the muscle, because the proximal ten in the top part actually weaves into the muscle and significant detail. And it's less common in the running endurance world. But in the, um, soccer community where they do a lot of kicking, reaching, you know, this terminal hip flexion position with the lengthened foot, that's like a big problem for them. And so when we're looking at something like a muscle strain, that's where the muscle gets injured to some degree. Typically there's three grades. So we've got grade one, two and three grade one. It would be more termed like a stretch where the muscle has been pulled longer than it would like. And this can happen through either a stretching mechanism, like if you slipped on something and your foot stood up in front of you. But it can also happen through a contraction mechanism, such as like you were running really hard and you felt it pull. Then we've got grade two, which is where there's actually some tearing of the muscle. And grade two is this huge spectrum to where you have. Are people going to be able to see the video? Uh, they can on the YouTube side though. So it depends. Yeah. We can tell them to go check the YouTube version for this portion of the interview if you want. Yeah. They're valuable to consider. So like grade one again there's a pull but technically no real tears. But then in grade two we got it. From where there's just one little tear that happens all the way until there's only one main fiber remaining. And so this is grade two, which is just this huge spectrum. And then we've got grade three, which is then where it's literally ruptured entirely. And so this can happen to one of the muscles. It can happen to multiple of the muscles. And it can happen in different parts of the muscle, all of which are actually somewhat valuable considerations in how you might approach them. This is because we can get into the exercise and training side of it, but we can have exercises that bias different muscles. Certain regions of the muscle. But in general, when we're looking at some sort of strain to it, we usually want to, to a degree, identify where it's happening. And that usually comes from having the person, you know, give feedback on, like where they might feel it, might have the person do some sort of contraction, like you might be laying on a bed face down and then bend your leg. And that can tell us where you feel that discomfort. But then we can also do palpation, where we feel along the muscle. And in a lot of cases across different injuries. Palpation isn't always super useful, but in hamstring injuries, it seems to be really valuable to where there's a pretty consistent correlation of the discomfort you have with palpation and your return to functional abilities. And so we can monitor someone's return to function by actually assessing with palpation, seeing the discomfort region and then seeing that region decrease. And that is correlated with someone's return particularly to running. Interesting. Yeah I know. Like with mine specifically. I had like the first part I noticed was kind of down near the base of the hamstring, almost to the where the back of the knee area was to the degree I thought, oh, maybe that's like a little bit of tendinitis or something at first, cause I didn't have it. It wasn't a situation where like, um, I felt it like pop or anything like that. Um, this was actually like, you know, when I was kind of returning to running after originally hurting it when I, when I heard it in the race itself, I didn't really notice anything too drastic in, in the acute sense. I just noticed like a loss of, uh, range of motion eventually to the degree where I couldn't really lift my back heel up without support. And I think my day was basically over at that point. Yeah. And that's what we call, like, protective guarding. Like your body recognizes that something has gone wrong, and now it's trying to minimize your likelihood of making it worse, especially with yours. Did you notice, because I know you had said that there was some bruising that the physical therapist knows later. Was it more to the side, like on the outside of your leg or more towards the inner part? It was actually the bruising actually was maybe a little bit, uh, further up than where I felt the discomfort kind of not square on the belly of the hamstring, but maybe just below that. Uh, and then a little bit kind of trickled down kind of towards, like behind the knee up and towards the upper calf area. And I, I suspected that was more just maybe pulling from it kind of. Yeah. Heading down that direction versus being the point of issue. And then the discomfort you notice when you come back to running was that more on the lateral side or the medial part of your leg? Um. It was more on the medial side. Okay. Yeah. So as far as hamstring injuries go, the most common location is actually like, on the lateral region, it'd be called your biceps femoris. And that's, uh, it's like 70% of hamstring injuries are with the buses femoris. Okay. Yeah. Yeah I remember. Well, I can give you some more details about when I started rehabbing it. Um, the movement that I could feel the most discomfort with, I had some weird things that, like, one was like, if I'd like, laid on my stomach and had, like, a resistance band kind of hooked onto my heel, and I would pull in or like, draw on my hamstring, and that's where I would notice the tightness the most if I would go on like a hip thruster or even do like I could even pick up like a hex bar and and have zero pain. Um, I didn't even notice it. Like I didn't go and just try to, like, drive full force on either of those movements, which I could imagine maybe would have been problematic. But just going through that mechanic with even some loading didn't draw any discomfort. It was really that kind of specific positioning and flexion point that I would get with, uh, um, with that resistance band move that I mentioned. Yeah, I think this comes into a pretty common theme that's not infrequent for a lot of individuals like we are. So the activities you mentioned before, like the hip thrust or the deadlift. Those allow you to perform hip extension, which is like I said earlier, one of the activities that the hamstring does. But when you perform hip extension in those types of actions, you have a lot of other tissues that can really support and perform that as well. Like you've got your glutes involved, you have your spinal extensors. And so like if you have an injury there, they can somewhat, you know, act in a way to mitigate that area, needing to produce as much force, particularly if you do it in certain types of way where the knees bend to a greater degree. Because typically when we perform any sort of hip extension, the knee is bent to greater degrees, like in the hip thrust, there's less involvement from the hamstring. Whereas if you perform knee flexion, pretty much only the hamstrings can do that. And so that's where any sort of knee flexion exercise is very important to use in the rehab process, but also in general for training the hamstrings because it's pretty hard to neglect them that way. Mhm. Yeah. It makes sense that that's why Nordics are so hard to do. Yeah. You're really isolating that muscle I guess. Yeah. Yeah. Nordics are very interesting. Yeah. Yeah. It's, uh, you know, I've been doing more of that stuff now, and I think maybe it was something I probably should have had in my rotation a little more specifically prior. And I may have avoided this altogether, but, um, doing more of the compound stuff, I found both beneficial from a time standpoint, but maybe not isolated enough to really give the hamstring enough reason to stay. Stay up to pace, I guess, is maybe the way to say it. Yeah. No, absolutely. Like, um, I love the general compound exercises, but when it comes to, you know, especially for any sort of running, whether it's, you know, slower or higher velocities, the hamstring is going to benefit from being challenged and loaded through some sort of knee flexion exercise. And, um, you can definitely have some crossover if you pick these quotes unquote, like compound movements that have a more greater bias towards the hamstring, like with an RDL, but with a trap or deadlift or like with a hip thrust. Those unfortunately, can not necessarily challenge the hamstring to a significant level. Mhm. Yeah. Yeah. I like the resistance band. Isolation moves too because they're so adaptable for where the person's at. And he can always go. I mean you could have no resistance band if you wanted to uh and you can kind of scale it up as to where you're at and then maybe get towards the Nordic at some point. Mhm. Yeah, definitely. Yeah. Yeah. Like Nordics are um. No, no, nor can provide a lot of value. Like there's tons of research investigating them obviously, because they don't require any equipment. So then researchers can just implement them anywhere. But they are incredibly hard and that is like a barrier to entry for them. With that said though, there is some specific research investigating that that level of difficulty might be particularly valuable in the context of the hamstring because it gets loaded usually, like for instance, in running at a long muscle length. And so then there's a requirement for it to have or a benefit of having longer muscle fascicles. And the Nordic specifically seems to encourage that because it loads it in a lengthening exercise, because as you fall forward, the hamstring muscle is eccentrically working. And then when you reach that break point where you fall forward, you're loading it to its peak abilities in a more lengthened position, and that can then encourage it to actually get longer and stronger at those lengths. I apologize if you mentioned it when you were describing that before, and I missed it, but when we're thinking of a typical running related hamstring strain or tear, is it typically in that eccentric kind of position where it's. Like stretched and loaded at the same time. Is that basically where these are all coming from for the most part, or are there other parts of the gate cycle that could potentially be a problem for people? Yeah, the vast majority of them are going to occur during that late swing stage. So as the foot is kicking forward just before it makes contact, that's like the most common location of it. And so it's, you know, lengthening out, contracting, getting ready for contact. And then the second stage is actually during the contact phase. And so both of the major times where the hamstring gets injured there, it's at a very long length. Yeah. Mhm. Yeah it would make sense. Uh, that is similar to sprinting then too I would imagine. Yeah. There's like a great video that you can see of Usain Bolt. Sorry. Sorry for Usain Bolt but uh I saw that video. Yeah. Yeah. Um, it's funny because, like, a lot of people don't realize that because, like, by the time you feel the discomfort, you're normally then you've already made contact with the ground and the foot is, um, coming back behind you. So. And some people grabbed their legs at that point and they think that's when they've heard it. But from enough motion analysis videos, it's like very strongly confirmed. It happens just before the foot reaches the ground. Usually. Interesting. Yeah. And then they're moving so fast in those sprint videos, they're unfortunately forced to take a few more strides before they fall to the ground. Yeah, exactly. Um, okay. So when we get to that point where, you know, the injury is there and you're kind of starting to kind of consider what to do next, there's a lot of information online I think about just like managing the pain. And I always look at it and kind of think, I wonder if this is sort of outdated or if this is still best practice. Um, a lot of stuff around icing, a lot of stuff around non-steroidal anti-inflammatory. Uh, I sometimes assume that's more like gen prop, like, okay, this person needs to get about their day and go to work, and they may as well do it with less discomfort. But what are we actually doing? Let's say let's say it's not that case. And it's like an athlete trying to return to sport as quickly as possible. Are there protocols that include those things that make sense, or is that something that you should try to avoid if you can, from a pain tolerance standpoint? Yeah. So I think you hit the nail on the head there. Like, clearly, you know, if this is Joe Blow who's just running on the weekends, then needing to go and get back to work, if that hamstring is driving him crazy, then it might be beneficial to do that, to allow him to get back to work as soon as possible. But on the flip side, the challenge with a lot of these things. So when we talk about icing NSAIDs, a key thing that they're looking to do is decrease inflammation. And you know, you've discussed it before. But inflammation can get a bad rap. And in the initial stage of injury and the inflammatory response is how we actually recover and heal. And so by mitigating it, we can actually have a poorer recovery in the long term. And it can decrease the adaptations that we actually desire and want. So usually the recommendation is that we want to minimize any sort of these like antiinflammatory type things. So icing um, NSAIDs in the first few days. And then once we get past that then it would be more of an option to introduce them because. The inflammatory response, at least from a key standpoint, is going to be the first like three days. And then after that it's likely not necessarily as vital. And we can use these adjunct therapies to start getting back into a return to activities. I still think that unless you have this high necessity to get back literally as fast as possible, because let's say you're a professional athlete who is making your money that way. Outside of those people, they're probably better off not using them too early in that window because like you mentioned, they can skew your pain tolerance. And then sometimes that might encourage you to do more than you might should because you're we often use pain as a guiding idea on, you know, like we might set a pain threshold of, okay, you can do activities up to a three out of ten, but if you alter what that level is, because now you're changing your pain response with either something like a chemical mediator, like an Nsaid, or these other options that skew your nociceptive abilities, then you might end up doing more than you could. And that's possible to then encourage this to actually take longer in the return to activities window. Mhm. Yeah. It kind of makes sense I know like with mine I had, I stayed away from all of that stuff for the most part because I was pretty certain that it wasn't going to be a long term move. That would be beneficial. Um, I did use a fair bit of heat and massage though. That seemed to be something that made it such that once I started kind of starting to test it a little bit and add some running, what I would oftentimes notice is it'd be a little bit of tightness and discomfort and that would more or less loosen up. And then it was just kind of a game of okay, now it's loose. I don't notice it, but make sure I don't push so far today that I start noticing it later in the day or the next morning, more pronounced because I worked it over when it was all loosened up and ready to go. Um, I assume there's probably there's probably some kind of similar like words of caution around that sort of stuff, too, just to make sure you don't artificially put yourself in a position where you're feeling better than than you maybe should, but also making sure you do the proper warmup so that when you do start testing the hamstring again, you don't end up really aggravating it because it's, you know, tight and not ready to go. Yeah, absolutely. Like you said, in general, warming up. And you know, heat massage can be a valuable part of that. Is going to generally decrease injury risk. And I would put that in along with the rehab process. But then if you feel better and are able to do more effortful things and you don't self-regulate and you just go ham afterwards, that's where you would put yourself in a negative position. But you know, like you're saying like you used general guiding principles of like, do I notice an increase in discomfort following the activity? Normally I like to give a 24 to 48 hour window where it's like, okay, we did X today. We were reasonable about it. Do we see a distinct increase in stiffness, soreness or pain in the next 24 to 48 hours if we don't see those factors rise, and we likely did something that was within your tolerance and recoverability? So then we can continue to scale up past that. Whereas if we see that rise, then we probably did too much too soon. So is it more or less ideal for someone who has already gotten that injury to kind of be on an every other day cycle then? So they give themselves that 48 hours between any stimulus at the ad. Yeah, likely, depending upon the severity of whatever you're doing. So in general, if you're performing some sort of activity that's going to be quite effortful and intense, then it's probably a good idea to do that. If we're looking at something that's going to be lower than an effort, like, let's just say that you decided to do some very low intensity isometric contractions. So you're just doing like you're mentioning a knee flexion. So you're laying, raising your leg up and just bringing it in and holding it. And you're not using much resistance on it. That's probably a reasonable thing to do on a more regular occurrence when you're in that early window of injury. And or if you were trying to do some sort of low effort stretching, which I know you mentioned for your own situation, you think like stretching wasn't necessarily a vital role in it, but stretching can be a useful consideration in a lot of these hamstring related injuries, particularly these strains. Maybe not tendinopathy, but at least in the case of hamstring strains. And so then, you know, doing some regular low intensity stretching movements can be beneficial on a daily basis. It would just be, you know, like if today you're going to go do a hard run, you probably wouldn't want to go do another hard run tomorrow. But that's kind of like a general principle of most intelligent programming anyways. Mhm. Yeah. No, that makes total sense. And I should clarify for myself, um, when I had the hamstring tendinopathy stretching didn't seem to be a solution, but with the strain it very much was. I found that that actually helped quite a bit especially you know, what I noticed was I had a couple, a couple days where I probably overdid stuff a little bit too much, and I noticed it rise a bit, and I luckily didn't double down on it the following day, so it didn't necessarily interrupt my return by any large degree. Uh, but when I noticed things really working well, I would probably spend a good 15 20 minutes before going out for a run, just doing some basic kind of like dynamic movements that were not not aggressive, but kind of putting me through the range of motion, um, some light stretching and stuff on the hamstring area. Some of those like resistance bands, hamstring curls and just really getting the area kind of nice and warmed up and, and a little bit more loose. And I would notice like when I would go for a run during that, after something like that, it felt quite a bit smoother and it kind of remained that way over the course of the day then too, especially if I did that kind of session again later in the day so that it would get just a little bit more, um, I think a little bit more action that wasn't really heavy. Loading. Um, there was a very clear, uh, trend for me where if I kept the pace and intensity low, um, and I'm curious to I'm sure you've got, like, some reasoning for this, but, like, if I would go this is relative to kind of like my pacing. But if I were like, like the first week back, if I kept it above an eight minute mile pace, basically no issues. I hardly noticed it at all. But I would notice if I would like. I'd say at the end of the run, just do maybe a couple light strides, or start pushing down into kind of the sevens. I'd start to feel it kind of tensing up a little bit, so I sort of stayed away from that. Then I sort of worked that over the course of a couple of weeks, down to where now I can do that at like a 730, and anything under a 730 felt a little dicey, but I could kind of keep it at that spot. And then I, you know, eventually got that back to, you know, now I've been running like well into the sixes and doing some strides into the fives, uh, with no discomfort at all. But had I done that stuff sooner rather than later, I'm almost certain I would have aggravated it. So, um, maybe we maybe that's a question or a topic in general is like, what is kind of like the pacing or the mechanical changes as you go higher in the intensity spectrum. Actually doing that could create an environment where I seem to be able to do quite a bit of volume if I had wanted to at that low intensity. But if I ramped it up too much, even a little bit would likely be problematic. Yeah. No, absolutely. That makes complete sense for me. Kinematic and kinetic standpoint from running. Like if you look at how most individuals run at slow speeds, there is less of a contribution from your hamstring because we don't have as significant of a stride length. And so one of the primary factors that changes between low to medium speeds to higher speeds, whatever that means relative to someone, is going to be that the stride begins lengthening out. And during that transition point of where the stride begins, increasing hamstring activity jumps dramatically. Like at low speeds, your hamstring isn't a major driver of your forward propulsion like it's predominantly done by your calf. But then as you enter into more effortful speeds and something like a stride where you're going to be opening up more on purpose, the hamstring is going to be kicking up dramatically. And so then what you did as a general approach is pretty in line with some of the ways that have been written out as protocols for return to higher, effortful running, like one of the main protocols comes from this individual named Hickey, who's out in Australia, where they outlined essentially like they set a distance out. Usually it's 100m and then they have people start walking, then they go into the lower for jogging. They don't give people parameters, but it's like 50% pace and then it goes up to um, performing multiple repetitions of that. Then once the person is tolerating it with minimal to no symptoms, then it goes up to 70%. And then gradually, once the person can do 70% with no symptoms, then we go up to 80%. And continuing this format until someone can reach higher levels of intensity with no symptoms because. Intensity as far as running goes. Seems to be the number one factor where the hamstring is going to be demanded to the greatest degree. And like I mentioned earlier on, it's one of those situations where the poison can also be the antidote, where it's pretty conclusive. Now that high velocity is running, some might call it sprinting, but strides could be very similar in this area where those seem to have a protective effect on the hamstring. But they need to be done number one progressively. So not going from zero to high efforts. And then number two pretty regularly. Like I'm not sure if this was an issue for you in your lead up to the race, but a lot of people will end up decreasing a lot of the intensity close to a race, and that could predispose someone like if they start. I know you didn't go and sprint during your race, but you know, like, um, a lot of people during different race events will start to minimize the high velocities that they have before it, and then they start to push it during the race. And that's when the person is actually at like the most significant risk of a hamstring injury. Interesting. Yeah. So keep the strides in at least when you're getting closer to race day. Yeah. Yeah. No. Absolutely. Like a lot of people in the strength conditioning community with these various team sport athletes, they'll have them perform high velocity running essentially every five days to some level, because that seems to be the window. And it doesn't need to be a lot like it can be essentially just a handful of strides done, middle of a session, end of a session. But that appears to have a pretty dramatic effect on decreasing the likelihood of experiencing a hamstring injury. Mm. Interesting. That's really good to know. I know like I mean strides have been something that have been around in the running world for forever presumably. But it's also something where they I mean their like any input they get their kind of popularity phase where now all of a sudden it's like strides every day and or like strides never. And um, you know, right now I think they're getting a lot more popular. But, uh, yeah, generally speaking, I think, like you talk about a fairly low impact input that you can kind of keep around without having to worry about too much like overtraining from them, but maintaining a fairly high level of, uh, um, exposure point to that relative to having to do like a full on short interval session or something like that. Yeah. I think the only problem that can arise with this is like when people are. No coming back to them. We're not doing them as regularly and they go for some good, effortful strides. They might not keep some quality running mechanics while they do it. And so then that's where, like they might in the pursuit of opening up for it, then start over striding. Or they might start excessively, um, anteriorly tilting their pelvis, or they might really heavily forward their trunk. And those things are possible, um, risk factors for that increased risk with the hamstring strain. Interesting. So is it better than to just like it if you're going to reintroduce strides as sort of like a precursor to a speed work development phase, and you've been doing just a lot of longer, slower running for a while. Should the stride be kind of relative to the pace that you've been doing more of than and rather than going from like, you know, that really easy maybe zone one pace and mechanics and intensity to like your full out sprint, do it just as kind of more of like a gradual acceleration where you're going like a certain degree beyond what you previously were doing before, kind of testing out that faster stuff. Yeah, that's a very good concept right there. Yeah. There seems to be a. The primary risk is going to be coming at like that when you reach that terminal, higher velocities. And so if you spend more of the time working initially on the acceleration, you'll probably readjust your gait mechanics as you're doing that. And by then that readjustment window, if you take it, then you'll start to get more comfortable with the technique to run at higher speeds, while also allowing your body to readjust and get comfortable with that loading versus going from zone one to a hard, hard sprint. Mhm. Yeah. No, it makes sense if it follows logic just like what you avoid going from one extreme to the other very quickly is maybe the rule that we can agree upon. Yeah exactly. Um I did want to ask this is maybe a somewhat unrelated question, but I think it's got some some potentially got some similarities. Here is how much, uh, have you kind of dove into, like the super shoe technology with running over the last few years? Have you been exposed to any of that? Oh, yeah. Big time. Yeah. Okay, cool. No, you'll be good for this, then. I'm. I'm really curious about this because I, like, somewhat suspect that my hamstring tendinopathy may have originated from super shoes. And I'm curious if you are able to speak to, like, potential mechanics. I mean, we know these things are changing our mechanics to some degree. Um, you know, the the marketing and all the, you know, the positive is, is that it's going to do it in a way that kind of preserves and allows you to run faster at the end and efficiencies and all these things that come with like the foam responsiveness, the plate in just the shoe, the shoe, the way the shoe kind of interplays with you and the ground. But whenever I hear something like that, where it's like, okay, we're changing something. When you're changing something with someone who's running as much as I am, or as much as some people are out there, that change usually has to be kind of phased in or dealt with very cautiously in the beginning. Have you seen any sort of reason to think that, like, the super shoes would maybe engage with the hamstring differently, or am I thinking about that maybe a little too individual? No, I think that's a pretty reasonable idea. So when we're looking at it like if we say, okay, you're running a seven minute mile and without the super shoe, we look at the distribution of the efforts coming from your hip, your thigh slash knee and then your ankle. What is driving that? I don't know. The exact percentages can vary from person to person. But then if we compare that number to you wearing a super shoe, the super shoe is going to decrease the amount of effort needed at the ankle predominantly. And so then how will you accommodate that? Well, you'll probably have increased demands at the thigh hip. And we see that with a major aspect like changing the drop angle in a shoe to where as the drop angle gets lower, the ankle does more work. And as the drop gets higher, the hamstring slash knee does more work. And so then that follows logic since most of the super shoes have a higher drop. And then in addition to that like with that increased bottom contour surface, it would maybe accommodate you to even extend your shank angle. So like your lower leg to a further degree, which then would mean that your hamstrings at an even greater length. So yeah, I wouldn't be surprised if that's a theme to arise in future years. Mhm. Yeah I think it's interesting. Just in general I think there'll be oh I think we'll see all sorts of, we probably already are, but I think we'll see all sorts of different injuries that come from it. And it might just depend on what I know, like there's people that never use them. There's people that only use them and then there are people who drop them in kind for quality sessions or race specific settings. And it's like, I generally tend to be that middle person where it's like, all right, I think there's obviously some performance potential with these products and, you know, everyone else is going to be using them. So it's like you're sort of giving yourself a disadvantage at this point if you don't engage with the product to some degree, but then it becomes a, you know, a scenario of what's the right dosage of it. So you're not necessarily creating a bunch of imbalances and weaknesses that you don't want to have to deal with down the road, versus getting enough exposure to it so your body can actually tolerate them on competition day, which is probably going to be one of the biggest loading days of your calendar year on top of it, too. So I think there's a lot of, uh, there's going to be probably a lot of interesting stuff in that kind of conversation as to like where to place them and to what degree, and phasing them in and out during different phases of the season and things. I think it probably fits with most stuff nowadays, but it's just one more thing we have to kind of consider. Yeah, no, absolutely. I think that that's very sound logic and it's not exactly like a new concept to try to rotate shoes between different kinds of sessions, but I think people might not consider, you know, like, what are the differences between their shoes exactly? And how does that impact the demands on their body? And like if you have, um, infrequent rotation of these different stimuli, then areas could be specifically not challenged as consistently. And so yeah, like if you are using the super shoe extremely commonly, it might put you in a position to where you're not having as significant bone loading, which then could predispose you to a bone stress injury. It could allow you to leave yourself predisposed to like greater amounts of hamstring demand, especially if you do have forward trunk lean during that. And whereas if you rotate these shoes, it might do a degree work itself out to where you're getting some positive stimulus at these different paces, different demands of running mechanics with different shoe wear, then challenging you in a way like pseudo resistance training while running. Mhm. Yeah. Yeah. I think it's, it's uh there's a lot to go in there. I wonder too, like just in general how much of a difference we would see with runners who have a fairly strategic well positioned strength routine that they do alongside. It's like maybe you're patching up some of those potential imbalances and weaknesses in the gym versus needing to be as aggressive about how you rotate shoes and things like that. Yeah, absolutely. Yeah. Do you. Do you have, like, a sort of like a, I guess, maybe call like a starter kit for. Strength work that you would think an endurance athlete would maybe want to consider as they're kind of piecing things together? Or does it get very specific to the individual? Usually when we're kind of getting into that world? No, I think like there's a handful of consistencies across the entire community, and then the adjustment should be reasonably made from person to person, given, you know, your running mechanics or your injury history. But overall, like most runners should probably be doing some kind of squat esque movement, whether that's a bilateral version like a back squat or a unilateral version like a split squat, and then some sort of knee flexion type exercise, whether that's a leg curl on a machine, a Nordic, and then some sort of calf directed work like a standing calf raise or a it could be a calf raise. And then in conjunction with that, probably some regular exposure to plyometric type movements. And that way you're getting a pretty reasonably well rounded comprehensive stimulus. after those things, like other stuff, can be valuable and important, but they're going to be lower on the totem pole. Like you can make some argument for lateral trunk strengthening with stuff like side planks, slash lateral hip development and then also for hip flexors. But I think that those particularly become more important at longer distances or higher velocities. So like hip flexor strengthening if you I can send you this paper later. Um, but there's one that particularly highlights the different contribution from different muscles depending upon the velocity that runners go. And like this group of researchers absolutely crushed this study that came out earlier this year where they took a lot of high level endurance athletes and then had them run a variety of different paces and did a very detailed analysis of it. And in it, it showed that, you know, like at low velocities, the calf basically reigns king for both producing force and then also absorbing force, but then getting into moderate to higher velocities. The hamstring kicks in significantly. And then at top speeds the hip flexors start to shine a lot as well. So. If someone's not doing something like a half marathon to marathon distance, like the hip flexor might not be drastically important, but at, you know, less than five K racing or racing distances, then it might be more and more important. And there seems to be, you know, that research plus also the research investigating different cross-sectional areas of high level and runners at those places that supports that kind of idea. Um, but then also for ultras, like you talk to a lot of ultra distance runners and you ask them like where was destroyed. In a lot of cases it can be, you know, the side slash in front of the hips and it's like an area that doesn't get trained a lot, usually in a lot of gym routines. Mhm. Yeah. Yeah I think that's interesting. I think like I've you know I've done a lot more like hip flexor strength stuff in recent years because it is one of those things where you're when you're running slower and when you're doing ultramarathons you're just not driving that as much. Maybe the mountain runners are probably exposing themselves to more of it, just because of the nature of the variability of the terrain they're running on, and what's required to go up a 20% incline versus running on a flat track like I do. But, uh, um, it is one of those things where I think, like there's, there's like these small muscles that can be very important in the grand scheme of things that when you're looking at like power weight ratio and bang for your buck, it's like, why not? Why not hit those ones and add them to the routine? But at the same time, you know, as a coach, I work with a lot of people who are like, they're pretty busy. And it's like, you know, you have a certain amount of time to train running wise. And we both kind of know strength work is probably a valuable input. And it's at that point it's like, well, let's make sure we're covering as much ground as we can with the limited time there is there. So I do always like to kind of hear, like what folks like yourself have in mind in terms of which ones are going to likely yield the most result for the least amount of input. So I'm not sending them to the gym for five hours a week when they just want to be out there running. Yeah, no. Completely agree. Like I work with a lot of people who are more in like the quote unquote hybrid space, trying to combine pretty decent endurance with pretty decent strength and similar kind of idea where like, it's the management of trying to optimize the time spent in each of those domains. And so not being excessive in the gym and trying to prioritize the greatest return for that. And that's where. Like those handful of exercises. Kind of raining. Rain King. Mhm. Yeah. No, I appreciate that. I think the listeners will really like to hear that. And I'm sure we'll see some of them putting it into their routine. Awesome. Well Sam, was there anything else you wanted to chat about with uh, hamstring or or fitness related stuff? Oh, man, those are definitely the top things. Like I think a quick summary of, like, if you have some sort of hamstring injury, don't just rest early on, try to do some low level introduction of, you know, loading it and then also some low level involvement of stretching it. You don't need to push those things. It's probably better not to, but then start to gradually scale that up. When you get back into running, do so in a gradual progressive format. Be consistent with it. Monitor your response. Try not to rush it, because there's a good chance that you know that the early window of time is not going to be as long as you think. But if you do something dumb in that window of time, it'll get lengthened out and then just, you know, have a myriad of training exposures as you return to running, going some slow, some fast different varieties of terrains, and then keep training your hamstring. Awesome. Well, thanks so much, Sam. Before. Before I let you go, I want you to let you kind of share with the listeners where they can find you, what you're up to, online socials and all that sort of stuff. Yeah. So the place where I'm most known is on Instagram. If I'm Sam Spinelli and then I'm also growing a new company called rehab Explained. We've got a mastermind where we release content, diving into different injuries, conditions, uh, performance side of things. We have lectures, practicals, helping individuals learn how to work with other individuals as well as, uh, for people who are dealing with an injury, trying to better understand it, constantly updating that and improving it. And then, um, yeah, that's the main option right there. Awesome. Sam, I'll be sure to link that to the show notes too, so the listeners can go and check that out when they're done listening to this. But I appreciate your time. And, uh, I've definitely learned some stuff that I'm going to make sure I stay on top of going forward and keep those hamstrings healthy for 2025. Awesome. It was great talking to you. All right, take care. Sam.