Jared Powell:
Without any further delay, I bring to you my conversation with Rich Willy. Rich Willy, welcome to the show. Yeah,
Rich Willy:
Thanks a lot, Jared. It's super to Be here.
Jared Powell:
No worries, Rich, you're the goat when it comes to bone stress injuries, and I mean goat as in the greatest of all time, certainly one of the, the most revered experts in the world when it comes to bone stress injuries. So it's no surprise that we're gonna talk about bone stress injuries in today's conversation. But we, before we get into that, Rich, who are you mate and what do you do?
Rich Willy:
Thanks, Jared. Really nice introduction. Yeah, my name is Rich Willy. I'm a I'm a physical therapist and I have a PhD in biomechanics and movement science, and I'm an associate professor at the University of Montana, and that's in the United States. So I teach in our physical therapy program. I do research here and I do research on running related injuries. And then I also do a lot of Department of Defense funded work also. And those two groups get a lot of the same injuries and a lot of the same principles kind of apply to both groups. So it's, it's a really nice, easy kinda segue when I move back and forth between those two populations. So besides that, I have a consulting and education business, a Montana running lab. She can find us on Instagram. I do some continuing education for professional organizations and, and, and clinics. I do some consulting with, you know, athletes, kind of, kind of of all levels everything from like recreational runner up to professional runners. And I do a lot of work in professional basketball also.
Jared Powell:
Awesome. Busy and varied life. Sounds good. Do you run personally Rich? What's your exercise choice?
Rich Willy:
Yeah, I mean, well, you know, I used to run a lot. I've been, I've been kind of struggling with a bit of a hip injury last, the last couple years. So I have femoral tabular impingement, and so been dealing with some issues with that that have been kind of limiting my running. But mostly what I do now, I do a lot of cycling, so I do a lot of road cycling and mountain biking, and then I still swam. I as I grew up as a swimmer, so that's my kind of my athletic background. But yeah. Yeah, so I like, I like doing a lot of that and where I live in Montana, it's a really awesome place to do that. I mean, I've got fantastic mountain biking trails, like pretty close to our door, so it's, it's easy to go to to go hit up some trails and yeah, it's a real, I think cycling's a real passion of mine, so it's something that I, you know, that I, I do a lot recreationally and gives me a lot of good time to kind of think about the projects we're working on and, you know, whatever.
Rich Willy:
Clear my head also, of course,
Jared Powell:
Yeah. On those long four hour bike rides, there's, there's tons to think about. What are you are you a fan of road cycling culture as well? Do you get into, do you watch all the monuments and the big road races? Yeah,
Rich Willy:
I mean, I used to do it quite a bit more. I would say not, not as much now as I, as I used to, but back when I used to race a lot, I used to watch 'em and, you know, I still kind of catch the tour a little bit and watch, I really like spring classics, so I always try to catch those, you know, whenever, whenever I can. So, yeah, and I watch, I still watch, you know, a good bit of mountain biking, so when, when cross country's on, I don't watch a lot of downhill, but I'll watch a lot of cross country mountain biking, so, you know, still really still really like that quite a bit. So yeah, I mean, outside of that, I mean, you know, basketball's a real passion of mine. I, my son plays a lot of basketball. I, I still play basketball. I love watching basketball. So I think, you know, sports wise, I think those are kind of the main, main things I like doing. Nice.
Jared Powell:
Who do you support in the NBA?
Rich Willy:
Oh, gosh, that's a, that's a great question. Maybe a better question is like who my son is supporting at the . Yeah. Because I kinda have to go along with that. Yeah, so he's a big Minnesota Timberwolves fan, so yeah, obviously we don't, we don't have an NBA team here in Montana, so. Mm. Yeah, he really likes, I know Minnesota,
Jared Powell:
They're doing all right. They sort of, they've got a star player now, don't they, with an Yeah,
Rich Willy:
They do. Anthony Edwards. Yeah, Uhhuh. Yeah, they've got a, they have a good team, so yeah, I think they're maybe not quite doing as well as they were last year, but they're, they're, they're doing well. I'm sure they'll, they'll make a deep run in the playoffs. Yeah.
Jared Powell:
Yeah. He seems like a generational talent that will hopefully lead the Timberwolves to, have you ever won a championship? The Timberwolves?
Rich Willy:
No. . I know they haven't
Jared Powell:
. Okay, well maybe
Rich Willy:
I haven't. Yeah, yeah, maybe, maybe someday. So, yeah. But yeah, I mean anymore now, I mean, like, you know, like our son, like, he's, like I said, he's a big basketball fan and you know, they're not so much like fans of teams anymore. Like I was, when I was growing, I was a big, I mean, I grew up during, when Michael Jordan would like, during his heyday, so I was a Big Bulls fan, of course, you know, and like, I think anymore now people follow the players more than anything. So if he were to go somewhere, I think he would suddenly become like a New York Knicks fan if he went to the Knicks. So
Jared Powell:
Yeah, I've noticed that as well. I've, I grew up a, a Knicks fan, weirdly , you know, from regional Australia liking the Knicks, and then LeBron came on the scene and I sort of just followed LeBron, you know, and now all of a sudden I'm watching Lakey games, like, so it's, it's very strange, which is different 'cause I'm a big fan of Premier League soccer in the uk, you know, I'm a diehard Arsenal fan, and players come and go, but you support the team. Whereas in NBA it's a little bit different. You can't, the, the players are so, their characters and personalities are so big, they almost outshine the team, so you tend to follow them where they go.
Rich Willy:
Yeah. I think that that kind of encapsulates it pretty well, so, yeah.
Jared Powell:
Yeah. And you are quickly, I wanna touch on, you're from, or living in Montana, and we'll just speak in a moment ago. The town you live in is where Yellowstone, the show is filmed and recorded. That's crazy. It's a, it's a very popular show with some, a very beautiful scenery. And you're saying that's, it's pretty accurate. That's how it looks there. It looks stunning. Yeah,
Rich Willy:
I would say, yeah, whenever I've watched it, I'm like right down the road from where I live. So like the Dutton Ranch or the studio set, I guess, if you would say, I mean, it is an actual ranch. It's just south of where, where I live. And yeah, I would say it looks a lot like that. People don't act like that . It's that's good to know. But it's good. It's certainly looks like that. Yeah, it, it's a, it's a beautiful place to live. So I think it's, it's a good place to raise a family and really huge running community. A lot of ultra runners. We have a lot of professional ultra runners who live here, so I get to work with, with those athletes and you know, a lot of people come here for the outdoors, so it's a, you know, if you're working in endurance sports like I do, it's a great place to live. Yeah,
Jared Powell:
Love it. I've gotta get there one day. I've got some friends in, it just looks like a stunning place. Alright, I could talk about that all day. Let's get into to bone stress injuries though, which is what we're all here for now. Rich is a bone stress injury fundamentally like an overwhelming of the reparative capacity of the bone in response to the stress placed upon it at university, we were taught that it is basically a mismatch between an osteoblastic or and osteoclastic activity within the bone. Is this accurate? How do we define a bone stress injury? Yeah,
Rich Willy:
Yeah, I mean I think, I think before we kinda get that, I do want, do wanna kinda give some props to some people that have really kind of been pretty formative for my, my career. I think like, like Stu Warden's Australian, he's here in the us I think he's been you, I really want to give, give a hat tip to him. Dr. Adam 10 foray for me, Dr. Emily Kraus at, at Stanford. I've really learned a lot, a lot from these people. Brent Edwards, a researcher here as well as a bio mechanist. So, so they've been really helpful with helping me kind of understand how these injuries kind of come about. And you know, for me, I'm a, I've worked as a PT for eight years before I went back for my PhD. I still treat. So I kind of, even though I do research, I always kind of look at it from this kind of clinical lens.
Rich Willy:
And so yeah, like why do, why do people get bsis? I think that's a, that's a great question. I think when you think about bone, it's kind of, you know, we're kind of constantly turning bone over when we're exposing it to load. We're developing like micro damage is kind of always occurring and we're kind of doing this like target of remodeling, which basically means you're just, you know, osteoclast coming in, they're, they're removing, there's micro damage and then there's a bit of a pause and then there's a replacement of that by the osteoblasts that are laying down your bone. And yeah, essentially what happens is that the accumulation of micro damage that is occurring due to repetitive loading is outpacing the amount of damage is so much 'cause there's been a massive spike and, and workload and it's just overwhelming the body's ability to adapt to those loads.
Rich Willy:
Or what can happen is that you can keep the, the loading the same, but you can have an impaired physiology from either hormonal disruption like inadequate fueling, so relative energy deficiency in sport or some other systemic issues. Stress is a big one. So that stress can really impair bones remodeling sleep. Also, then you can get this accumulation of micro damage and if that continues unabated, meaning you're continuing to load after a while you will develop the bone stress injury. We've moved to this term of bone stress injury away from using like stress reaction versus a stress fracture. And it's, the reason for that is that, you know, there's trying to convey that this is 10 from a stress reaction to a stress fracture because a lot of times people be like, oh, I just have a stress reaction and go ahead and run through this injury.
Rich Willy:
But of course if you continue doing that, you're not abating this repetitive loading, then that will progress onto a bone stress fracture. So the preferred term is bone stress injury. And so that'll be a term I'll be using kind of the rest of our conversation today. But, you know, really what, what's happening there is that the, a stress reaction is lower grade bone stress injuries typically just involve some periosteal edema. Once you get to, that's like grade one and grade two would be perote edema plus bone marrow edema. And then grade three is just a little bit more of, of both of those. And then a grade four is when you get to, you actually have cortical disruption in addition to the bone marrow edema and this periosteal edema and that's when you can start to see it in a radiograph typically. So everything before that can't see on a radiograph basically gonna be seen by MRI. And that's why these injuries get missed for a long time because people get some bone related pain, they go off and get imaging, they might just get a radiograph and they're, they're not mm-hmm really visible on radiograph quite yet. Well,
Jared Powell:
Let's go straight to the importance of radiological imaging right now then. So is that the gold standard diagnostic tool an MRI these days for the diagnosis of a bone stress injury? Yeah,
Rich Willy:
It, it certainly is. So I mean it used to be that like before, like two decades ago, I think sometimes people would use bone scans and really, you know, MRI is the standard practice when it comes to being the most sensitive and specific. So it's considered to be the gold standard for diagnosing the injuries. Sometimes people use a CT scan, those are not as good when it comes to like the ity and specificity CT scan can be really helpful when you're looking at like these more complex bone stress injuries such as like a navicular BSI as kind of a classic example of that. So usually like the MRI is used to diagnose it and then a CT scan is really helpful for like visualizing this crack or this micro crack as it's started to close up as it's starting to heal. So sometimes people will use CT scans more for like monitoring healing.
Rich Willy:
But yeah, MRI is really the way to go radiograph, you know, for, I think for non elites and also for sites that are low risk, that's usually the first line of, of imaging, if you will. And then if symptoms continue, most of the time people would then go get an MR. I think for most of the athletes that I work with, because I tend to work with some higher level athletes, we just try to get 'em into getting this MR MRI done as soon as possible. And particularly if it's a high risk site, I mean you just bypass radiograph altogether and just go straight to MR MRI for the high risk sites,
Jared Powell:
Let, you've mentioned high risk and low risk a couple of times. Can we talk can we define high risk versus low risk bone stress injury, please?
Rich Willy:
Yeah, yeah, of course. Yeah, so, so high risk sites are typically sites that where if you have a bone stress injury, it will not heal typically on its on its own. You have to do some pretty drastic measures to do so. It usually means, you know, non-weight bearing for a prolonged period of time may need surgical fixation. And the reason for that is a couple reasons. One would be low blood supply to the region. The second one would be that it's very difficult to control tensile loads across the bone. And bone is designed for compression. So when you're compressing the bone, it you've got a fracture there or like a BSI, it's typically gonna heal. Okay. But if you're applying a lot of tensile forces to that bone site, it's not gonna allow that bone site to heal. So kind of a classic example would be like a fifth metatarsal BSI.
Rich Willy:
So at the base of the, of the fifth, you know, p pro brevis tendon is gonna continue pulling on that bone and because of that, that's gonna be a high risk site. And so, so bone is, bone is kinda the opposite of tendon. It's a good way to kind of think about it is that, you know, tendon is designed to transmit tensile forces and as we know, tendon tends to do quite poorly with compressive loads. So that's how we get like insertional tendinopathies bone's, the exact opposite bone does very well with compression loads, but it does very poorly whenever you're applying any sort of tensile loading to it. And so bone tends to be the weakest with, with those tensile forces. So other kind of classic places of these high risk bsis would be the anterior shaft of your of your tibia. So anterior cortex, bsis, those are, those are very high risk.
Rich Willy:
If you've ever seen someone who has like a spontaneous fracture on tv, like some sports, like there's a, like an MMA like hunter McGregor for instance, he got kicked in his anterior shin and he had some anterior shin pain prior to that. That's a classic example of a spontaneous fracture that can occur. So these high risk sites can go on to develop into a full blown fracture. The other site we see is, that's a kind of real dangerous fracture would be femoral neck. So the superior region of that femoral neck is a site of tension and those also are, are very dangerous and those are kind of immediate surgery. So they need to get some sort of surgical fixation to keep them from progressing onto a full-blown
Jared Powell:
Fracture. Cool. So fifth mat femoral neck and anterior tibia are some high risk locations. What about some low risk?
Rich Willy:
Yeah, I mean the most classic one would be posterior medial tibia. I think that's the most common when you, when you look across bsis, I mean that's the thing we, we often, you know, it's really important to be able to recognize these, these high risk sites, but the majority of bsis and runners and to be in these, these low risk sites. In fact, when you look in in male runners, 75% of all bonet stress injuries are posterior medial tibia and metatarsals. Most often it's gonna be the second metatarsal or maybe perhaps third. The reason why it's the second metatarsal is because it's the, the longest and the skinniest bone or metatarsal that is. And we also push off underneath that, that second metatarsal head. So you've get this bone that is the narrowest and so it bends the most and so it's gonna get the greatest amount of tensile forces on it.
Rich Willy:
So, so those are, those are low risk ones and, and if you manage them quite well, they will typically resolve in about between, depending on like the severity of the grade you might get. Like you might be back to running in this as few as six weeks, maybe a little bit longer than that. So those are, those are typically quite a bit, quite a bit faster. The high risk sites though, so anterior cortex, BSI, so anterior tibial cortex I should say you're looking at versus, you know, six to eight weeks getting back to running, you're looking at more around the lines of like five months. Mm-Hmm. So it's a, it's a big, big difference. Same bone, but just different site for the BSI.
Jared Powell:
Yeah. And so you mentioned the medial tibia. So is that just MTSS what we're talking about there as a low risk bone stress injury? Is, is that what we're calling MTSS these days? Is it just a, a low risk bone stress injury? Yeah,
Rich Willy:
That's a, it's, it remains this point of controversy I would say. I think a lot of people kind of kind of debate that and so there's some, there's two different schools of thought. I think the first one would be that, that it's on, this is MTSS, which is, you know, essentially grade one, maybe grade two BSI, so it's got this PERO edema might have some bone marrow involvement that it's on this continuum to developing into a full blown BSI. Then there's the other school of thought that's like, you know, you're, you're looking at the main difference between a, you know, MTSS and a true BSI is that you have, it's a much bigger footprint. So typically MTSS involves, you know, maybe about 10 centimeters of tenderness along the bone tends to be quite even. It doesn't have like, like a more versus like a, like a true BSI, it might have a very vocal tenderness on the bone, you know, less than five centimeters.
Rich Willy:
And it typically is, you can even like even palpate this like a little bit of a lump on the bone. So again, you've got these two different schools of thought. You've got this idea that it is on the continuum to getting a full blown BSI. And then there's this other school of thought to saying, look, this is a totally different clinical entity. These people who have MTSS typically will not go on to developing a full blown BSI and I would've put myself in that camp. I, I think for most people, medial tibial stress syndrome or shin splints, whatever you wanna call it, it's pretty typical to get if, if you're, if you're new to running, if you're an adolescent runner, it's very common. It's probably one of the most common running related injuries. I think if you know, you, you wanna manage those quite a bit differently, those are gonna be like MCSS.
Rich Willy:
We tend to manage those more with like management of loads improving tissue tolerance in the region. So we try to keep people running, particularly adolescent runners because we wanna do whatever we can to keep them as active as possible for the actual like full blown BSI for those you need to have a period of deloading or relative deloading and that's gonna be a gradual return to activity after that. So we, we manage them quite a bit differently. And so I I I think it's important that people are aware of those differences and how to differentiate between the two of
Jared Powell:
Them for sure. Are you, would you be using MRI to get a, a greater understanding of where they might be on that continuum? Say if somebody come in with a, a run of the mill MTSS presentation, would you be MRI that patient?
Rich Willy:
No, I don't think so. Basically when someone comes in, let's say someone comes in and have f tibial pain, they have pain, they pain with running, pain with loading, they may have pain at rest is pretty typical of any sort of bone related bone stress injury. First thing we'll have 'em do is probably like, like a hop test. So we have 'em do a single leg hop, you know, probably 10, you know, 10 repetitions. So we can try to, you know, replicate this pain. Then we examine the region so we can kind of map out how big this footprint of bony tenderness might be. And the rule of thumb is really nice clinical prediction rule out of Israel. If that footprint of tenderness is more than 10 centimeters for sure it's gonna be MTSS. That's what has like a hundred percent sensitivity that it is not going to be a bone stress injury. If it's less than that you should send them off to get imaging. So anything greater than 10 centimeters, it's MTSS. Anything less than 10 centimeters you should consider getting imaging and that's gonna be MRI. Awesome.
Jared Powell:
And that's irrespective of the irritability of their symptoms. Say for example, they come in and they're limping and they've got this antalgic gait and they're highly disabled by the pain, would you still stick to your guns there?
Rich Willy:
Yeah, I think if someone's like that then I would probably send 'em off to get an imaging and I think, but I mean, you know, most people aren't coming in like that. Most people are, they're like, yeah, it hurts. I I have some trouble bearing weight I can't run. And then we can kind of make some decisions from there. Yeah, you know, usually like those are easy, like the clear cut extreme versions like yeah, those we're gonna send off for imaging for sure.
Jared Powell:
Yeah. Nice. Let's go back to the etiology of a bone stress injury for a bit. We got a bit sidetracked there or I got a bit sidetracked. It's gonna happen a lot. So would you say load, external load is the primary driver or contributor of a bone stress injury in, in most circumstances? Or is it this underlying bone physiology sort of presentation that is more susceptible to just normal loads that is driving bone stress injuries for the most part? Or is it a 50 50 or does it depend on the location of the fracture site?
Rich Willy:
Yeah, it's probably funny. So I go to American College of Sports Medicine, which is our, our big sports medicine meeting here and you know, you've, you've got the group that's looking at low energy availability as relative energy deficiency in support group. And then you've got the, the clinical or the biomechanist group and, and sometimes our talks are running in parallel, so we've got one group then they're running at the same time. And so more so lately there's been a big effort to try to try to combine these sessions and to talk more in a and from a causal standpoint so we're not just isolating risk factors or trying to look at one single mechanism because all these things like cascade into one another. And so, and, and runners they, you know, they often are like, there's such a strong psychological component to these bone stress injuries and we tend to see a lot more like exercise compulsion and dependency in these runners.
Rich Willy:
And so that can drive a couple different things. We can drive your energy availability because you might be exercising more can also drive the amount of energy that you're consuming. And so that can have a big, big role there. And so you're looking at, you're looking at kind of both things I guess is what I'm trying to get at is you can be under fueling and also overloading at the same time. And that's what we see a lot in our, in a lot of our runners. For some runners it's inadvertent under fueling and so, you know, doing a lot of like zone two kind of endurance pace running if you will. And then suddenly they're starting to ramp up for like a half marathon, they start adding in some more like higher intensity work and so their overall caloric expenditure goes up and then they're just not increasing the amount of fueling that they should be doing to replace the calories that are, that you know, that they're, that they're losing along the way.
Rich Willy:
And so they get into this inter like this inadvertent energy deficit if you will. And then because of that they don't have the energy to replace the bone that they're losing. So, you know, I would say when you're looking at the actual bone that's involved though, you can kind of like reverse engineer how they got this injury. So we know that injuries or bone stress injuries that are more proximal, so trabecular type bone, so this is like our spongy type bone that's like in our sacrum femoral neck lumbar spine. If you're seeing an athlete who has bone stress injuries in those sites, you should not be thinking about about biomechanics. You should always be thinking about under fueling and these athletes some sort of systemic issue. And the reason for that is that like trabecular bone is very highly metabolic, so the energy kind of draw from that type of bone is quite high.
Rich Willy:
The bone also turns over a little bit slower. And so because of that, when someone goes to like for instance, then they get like a, like a dexa if you will, you often start seeing low bone density in those sites before you start seeing them in like more distal sites like tibia and metatarsals. So like anytime you see someone who's got an in trabecular sites that has a bone stress injury, you should immediately think that this is relative energy deficiency in sport and and start to rule that out. And I think that for me as a physical therapist, that's not something that I do. I screen for that, but I refer out to a sports medicine physician and also registered dietician who, who can help out with that. So these more like distal sites, so metatarsals tibia for there we start thinking this is probably more gonna be related to biomechanical loading. So we really wanna be paying a lot of attention to that. That doesn't mean that like that low energy availability is not factoring in, but we do know that we're gonna need to pay a lot of attention to biomechanics when there's athlete's making that return to a sport, return to running basketball, what whatever it might be. Yeah.
Jared Powell:
Okay. And so when you are thinking more about biomechanics, are you thinking about changing the way they run? Are you putting an orthotic in their shoe? Are you changing shoes? Are you, what are you talking about with biomechanics?
Rich Willy:
Yeah, I mean I think, I think it's kind of worth taking a step back and like thinking about like what contributes to bone, bone loads or bone forces. So it used to be thought that it was that we were talking about like, like impact forces. So you hit the ground hard, you're impacting the bone and then it's gonna res result in greater bone loads. But really when you look at like let's say the tibia for instance, the contributions to tibial bone loads typically like tibial bone compressive forces when you're running it kind of an endurance pace end up being about nine body weights of force. And you know, we, we all know that when you're running your ground reaction forces ends up being about two to two and a half times your body weight. So you've got nine body weights of tibial bone force of which two to two and a half times your body weight is coming from your vertical ground reaction forces, which means that there's, you know, six and a half, seven body weights of force that's actually missing and that's coming from your plantar flexors.
Rich Willy:
So your muscle forces are the, the, the number one driver when it comes to con like contributing to overall bone forces. And so, so for the tibia it's always gonna be the plantar flexors for the metatarsals it's also gonna be your plantar flexors because those are what's pushing you off the ground. So as you push off more, you're always thinking about plantar flexors navicular, it's gonna be plantar flexors also, but of course posterior tib and you can kind of go the whole way blind for the femur, it's adductor magnus hamstrings, those are gonna be very big contributors there. So when it, when it comes to like controlling biomechanics, I'm thinking about it two different ways. The first thing is how can I progressively load this person with a progressive loading program so I can improve bone health store, you know, bone mass and bone strength.
Rich Willy:
And so we do that by thinking about like for instance for tibia, how can I add progressively add plantar flexor forces into this person's program so we can strengthen the bone up and prepare this person to go back to running. Then when we actually do get them back to running, we're thinking about how can we control those bone forces via controlling plantar flexor forces when they're going back to running. So we would avoid things like running in a zero drop shoe for instance, which is gonna really increase our plantar flexor forces. We'd be thinking about reducing speed work, which is going to, you know, increase plantar flexor forces as well. We might do things like put 'em in a rocker soled running shoe. So a rocker sole shoe is going to reduce the moment arm acting on our planter flexor so the planter flexor forces will come down there as well. So I mean eventually when we get this person back to running, we'll start, you know, weaning that stuff off. We don't want to make it so that they have to run in a certain way or run with a certain shoe forever. Obviously for like an elite runner, they need to get back to running it tracks bikes or something like that, but those are gonna be the last things that're gonna add back in because we know that those are gonna be the most stressful types of running that they might do.
Jared Powell:
Yeah, that makes sense. Broadly what is the role of muscular strength in the perhaps prevention of a bone stress injury or the, the, or the causation of a bone stress injury? So are weak calves, for example, associated with a higher risk of developing a a tibial bone stress injury? Is there any sort of relationship there?
Rich Willy:
Yeah, there is actually. Yeah. And so I think this is a big debate and I can't tell you how I, where I fall on it and, and we know that we know, like for instance, there's actually some really nice work out of out of Australia looking at at at track and field athletes and we know that athletes pound for pound and the same athletes the same height, same mass, same sex doing the same sport. We know that if their calf is one centimeter smaller in diameter or circumference, we know that they have about a four times greater risk of developing a bone stress injury than the person who has a larger calf. So I think there that like the plantar flexors are doing something, they're distributing loads and so forth, that's probably not really what it is. It probably is, is that you've done your homework to get this larger calf Mm, by doing more exercise, you're being exercising consistently and because of that you've got a stronger bone underneath it.
Rich Willy:
So muscle is kind of, has this kind of like synergistic dominance on bone. So we, you know, muscle needs bone to have a place for, for the any for for moment arms for attachment and then bone requires muscle to exert muscle forces on it so it can, you know, have this osteogenic kind of capacity. And then there's a lot of hormonal crosstalk that's also occurring there. So the more that you're loading your muscles, it's not that like it is preventing or controlling loading per se, it's that you're mechanically stimulating the bone and because that the bone's gonna get stronger. So we see this quite clearly in jumping athletes and so when you, when you look at jumping athletes, the hurdlers long jumpers, someone who's jumping off one leg and then they're landing on it on their opposite leg, their takeoff leg always has a larger calf and it always has a larger and stronger underlying tibia underneath that and their landing leg. This just gets back to this idea that like muscle forces are so much more important than our actual, these landing forces are impact forces. The landing leg has a smaller calf and also has a smaller tibia as well.
Jared Powell:
That makes sense. So it's not as, as simple and as reductionist is saying, just simply build up your calf strength to perhaps absorb more force to spare your tibia. It's building up calf strength is perhaps going to build up your bone strength simultaneously as well. Is is maybe just making you a better athlete fitter and and more capable of tolerating the loads that you're putting on your system? Yeah,
Rich Willy:
Exactly. I mean you see the same thing when it comes to like achilles tendon stiffness for instance. Like a bigger calf has a stiffer and larger achilles tendon attached to it and because of that, that tendon is gonna be less likely to develop achilles tendinopathy. You know, we, where it kind of gets a little bit, can you even take a step back further and we look at the military and one of the number one predictors that someone's gonna develop bone stress injury during basic combat training is if they have a slower five kilometer runtime. You might sit there and think like, hey, well aerobic capacity must have this magical protective effect when it comes to reducing our risk of developing a bone stress injury. But really it's just that that person has habitually done the work to be fitter and because of that, when they get to basic combat training, there's not this, they're not gonna experience this massive spike in relative workload that the person who's, I don't know, running a 25 minute 5K versus the person who can run a 20 minute 5K. Yeah,
Jared Powell:
I love that. That's the detail that I want Rich. Thanks for that. I think we've covered that nicely. In terms of the etiology, we've mentioned a little bit of red s we've mentioned the difference between impact forces and muscular forces. What about as a clinician? I, I was kind of brought up in an era where we, we wanted to try and get to a generic number of calf raises in people before they would go back to running. For example, you know, it's the 20 to 25 calf raises, single leg calf raises that they should be able to do. And this was then instituted into sort of every sporting team that I worked with. Is there any evidence that muscular endurance of the calf, which is a good one to talk about, is associated with the development of a bone stress injury or needs to be achieved in order to get back to running from after a bone stress injury? Are there any sort of hard and fast numbers of calf raises that people should or shouldn't be able to
Rich Willy:
Do? Simply No, not at all. So yeah, I mean you see, you see a lot of these like running clearance tests and mm-hmm software people have to do like 30 single leg calf raises or something like that. You know, again it goes back to this idea that, you know, muscle's really cool, but I mean, sure if you can do more calf raises, you probably have a stronger calf. And so because of that your bone's probably a little bit stronger, but when you, when you're looking at like how much bone force is actually being experienced by this tibia or whatever bone, it's not, it's not very high when you're doing a calf raise. So a single leg calf raise ends up being about the thir a third of the bending moment or the, like the bending torque if you will, in the bone where the, in this planter flexor is contracting at bending this tibia backward.
Rich Willy:
It's only about a third of that. So doing a single leg calf raise, whether you do one or you do 30 of 'em, the forces on the this person's tibia is actually quite low. But when you do look at what exceeds the loads on someone's tibia, a single leg hop is what gets it done. So, and you need to do that single leg hop in a very special way. You need to do it like a pogo hop where you're minimizing your contact time, you're getting off the ground very quickly, you're not absorbing the load from your, your hip and your knee, your ankle's doing all the work. And if you do that and you're kind of punching the ground as you're doing your, your pogo type hop, that force, that bending moment exceeds running. Like if you're running, I'm trying to think like kilometers per or or minutes per kilometer, but o off the stick with minutes per mile, if you're looking at running like an eight and a half minute mile, you're, you're gonna be exceeding that quite, quite easily.
Rich Willy:
And even more so if you do a forward single leg hop because the, your planter flexor are responsible for vertical support and also vertical support plus forward propulsion. And so a forward single leg hop is if you really want to be conservative, if you can do a forward single leg hop and you can do 10 reps of that and you don't get any bone pain with that, that person's gonna be able to go back to running. Now if you can do a single leg calf raise and you can do 30, you're, you're not even in close to the loads that someone's gonna be experiencing during running. And so what we see a lot of times when, when people are using like a single leg calf raise is a clearance test to go back to running is that they're prematurely returning to running and it's not unusual for that person to have a big setback because they aggravate the site, they just weren't ready for running yet.
Jared Powell:
Yeah, great point. The test, right, it tests your CARF endurance, it's not really testing what your bone can tolerate. So that's, that's really good. Hey Rich, I've got a question about a building healthy and strong bones. Is that primarily done in your youth? IE if you're a youth athlete, is there, and I assume there's more bone turnover, is there a relationship between being a youth athlete and doing a lot of running and high impact sport and building your bones then? Is that, does that, is that preventative later on in life or can you build healthy and strong bone at any age? Even as we get older into our forties, fifties and sixties?
Rich Willy:
Yeah, I think is an area of kind of fascinating research right now. And, and Dr. Belinda back, you know, who's, who's there in Australia, she's doing some wonderful work when it comes to working with people who have osteopenia and osteoporosis. So I really recommend people kind of checking out some of her work if you haven't already, I would assume most of the listeners are are familiar with that. So what I'll do is I'll kind of focus more on like how can we prevent for bone health And that starts when you're an adolescent and pre-adolescent. So feel like Perry puberty is the most important time. And so like some really nice statistics, if you played basketball as an adolescent, you have half the risk of a bonet stress injury later in life. So 10, 20, 30 years later your risk of developing a bonet stress injury. We see this very clearly in NCAA runners in the United States.
Rich Willy:
We see it also in the military. We see too that if you play soccer that 30 years after you got done playing soccer, that you have a 40 to 60% lower risk of fracture. So these multi-directional sports, they are highly protective against bonet stress injuries. And the reason for that is that you're loading the bone in multiple directions and the forces are higher too because you're jumping and you're sprinting versus endurance. Running this load is quite boring for the bone and the forces aren't terribly high. And so essentially what you wanna have, you wanna have the bones of a basketball player but be a runner. And so that's gonna be the best way to kind of get it done. And if you can do that and you're not specializing in running too early in life, you're gonna have a much more robust skeleton. Where we're starting to see some issues is in runners who start specializing a lot earlier, the, it's really fascinating.
Rich Willy:
Kinda what happens is that first of all their bone is not any larger. I thinking about bone, I'm thinking about tibia 'cause that that's the most studied lower limb bone. It comes to like bone size and bone strength. But tibia is not any larger than someone who's not physically active. So more someone who's more sedentary. But the other thing is that's, that's really quite weird is that their tibia actually changes shape it, it looks much more along and so it's more, it's kind of aligned more front to back. So it's can resist those loads of this tibia bending backward versus the multi-directional athlete, they develop a tibia that looks more like an sase triangle so it's able to tolerate loads from all different directions and that bone and the multi-directional athlete is also quite a bit larger too when it comes to the actual size or girth of it.
Rich Willy:
And that's gonna be a much stronger bone. And so it's very difficult to change bone size as we get older as we get into adulthood. And the reason why that's really important is because it was this polar moment of inertia. The further you, you move the mass of a bone away from the center of it, the stronger the bone is gonna be. And so it's very difficult to change that. And so while you can improve bone density, you know, alter that a little bit in your twenties and thirties, you cannot change, you can't make someone give someone like a, you know, a larger tibia for instance. And so we, we see that there's some really cool paper that came out of the K arm services and they looked at by malleolar width. So they looked at the, the distance between your malleolus and that's a pretty good prediction of lower limb skeletal size.
Rich Willy:
And for every one millimeter that you had a narrower bi malware with, I'm trying to remember the actual statistics, you had a greater risk of a developing a bone chest injury and that's because that that bone size is gonna be a lot smaller. So yeah, you know the best time to do this as an adolescent. So we, we try our pre-adolescent and so we, for us in the adolescents I work with, we work very hard to try to encourage them not to specialize in running until they get to perhaps the age of 16 or 17. And then they can start, you know, thinking more and more seriously about doing the specialization. But it's really important to be doing multi-directional type loading activities earlier. I
Jared Powell:
Love that that fits my bias Rich. I've got a, a strong inclination that kids should be doing lots of different multi-directional sports and shouldn't be specializing in anything until they're mid to late teens. And I think there's evidence for, you know, we look at some of the best sportsmen and women of, of all time and they've often done a lot of different sports in their youth. I know Roger Federer, the tennis player, did a lot of different things in his youth. We see Raffa Nadal did the same sort of thing. I mean runners are perhaps a bit of a different breed. I'm, I'm thinking of the Inger Brits right now who have been trained as, as runners since they were, you know, barely out of nappies, although they were cross country skiers as well. So perhaps they did get a little bit of cross training. But runners seem like a different breed where they run and they run and they run and they've run their whole life and they just keep running and running and running. So if you were treating an adolescent runner sort of per pubescent, would you encourage them to be doing some multi-directional work around their running? Would you like proactively advise their parents that's what they should be doing? Yeah,
Rich Willy:
I mean this is such a, it's a tough topic, tough conversation to have with parents and the athlete, frankly, a lot of times it's the parents who want their kids to specialize and want them to run more year round. And I mean it's like that with all sports like soccer or basketball, I mean it's this like this big push for specialization. There's some really important gender differences there and that's it. Female runners or females tend to specialize in sports a much earlier age than males do. So I think that's might be one of the reasons why we see a higher rate of Patel femoral pain and female athletes because they, we know that sports specialization increases the risk of Patel femoral pain. We know that sports specialization also increases the risk of bone stress injuries and low bone density. And so I just basically show the parents and the the athlete the data.
Rich Willy:
And when you look at athletes who run, who are, who are teenage athletes or pre-adolescent athletes who are running more than nine months a year, 60% of those athletes have z scores of negative one or below. Mm-Hmm. Meaning that 60% of runners who specialize as an adolescent have impaired bone health. Those are pretty important data because those, these are your peak bone building years. And so look, this is kind of what you're setting your athlete up for. And a lot of times, of course everybody, and particularly like teenagers, I soon to be a teenager and they always think that they're exceptional and that they're gonna be the exception to the rule, but the evidence states otherwise. And so there's probably also besides a loading standpoint, there's probably also a very important interaction with relative energy deficiency in sport and that as we specialize more in, in running or you know, a sport that is very much focused on body type and there's an aesthetic to it as well that it probably, I think we're gonna start seeing some papers coming out that there's a higher risk of low energy availability or a relative energy deficiency in sport and the adolescent athlete, particularly the female adolescent athlete who specializes in running.
Rich Willy:
So it, it becomes a little bit challenging because the athlete thinks that they need to specialize to perform at a higher level. Parents often do as well and as much as I can show 'em the data that, as you mentioned earlier, some really ni wonderful paper in general sports medicine that showed that athletes who specialize in high school have greater achievement as a high school athlete but tend to drastically underperform as a college level athlete or as a, as an adult. And one of the things that we see a lot are runners who in, in high school are running the volume that collegiate runners are running. And so when they get to college level, then they actually don't have any place to really grow because they've already been training at that level already. So anyway, so what I try to do is try to work very hard is the best thing you can do is don't specialize.
Rich Willy:
The second best thing you can do is make sure you plan to take some times off, time off during the year. And then when it comes to, and you need to be doing some sort of supplemental loading to do that, you need to try to mimic some of these multi-directional activities. And so for that we, we tend to really recommend a lot of plyometrics for our athletes and we put a lot of the high school athletes that we work with on an, on a this plyometric type program. We also do some lifting when it comes to deadlifts and as well as like heavy back squats so we can try to target the lumbar spine.
Jared Powell:
Yeah. Awesome. Before we get onto the treatment, I've got a bunch to ask you about that. I wanna ask you, do bone stress injuries mainly afflict endurance runners or do are sprinters vulnerable to developing a bone stress injury as well?
Rich Willy:
So what, what we see in endurance runners, you know, we see this, this injury that probably is a combination of, of high repetitive loads plus impaired physiology due to relative energy deficiency in sport or anything else that's going on there. So this would be, there tends to be some, some real physiological drivers when it comes to endurance athletes for sprinters, I would say sprinters and basketball players, soccer players, there certainly can be a low energy availability component to it. It seems like it's perhaps less less of a factor and we're talking about just much greater biomechanical load. So those athletes tend to get different bone stress injuries as well. So when you look at endurance runners, they tend to get a lot of tibial bonet stress injuries. They tend to get a lot of second metatarsal bone stress injuries for basketball for instance. They tend to get, they definitely get some tibial bonet stress injuries, but they tend to get metatarsal bsis primarily, predominantly in the fifth metatarsal.
Rich Willy:
They get a not a lot of navicular bsis for the tibial ones that they get. They tend to be more the anterior cortex bsis. So you have to be very aware that when you're working with basketball athletes or the jumping athletes that you need to be very aware that they're more prone to these higher risk BSI. So basically the fifth navicular, that's a high risk site that we haven't mentioned yet. And also anterior cortex, tibial, BSI, so those, those are ones that we, we tend to pay a lot more attention to. And the reason is, is that those muscle forces are just so high. So we've had some athletes in our lab where we look at these, you know, tibial compressive forces and you look at the average endurance runner, as I mentioned earlier, around nine body weights for someone who is doing a maximal jump, like jumping as high as they can off a single leg, you're talking about 19 or 1819 body weights of, of tibial bone force. So these forces are, are far, far higher when it comes to the jumping athlete.
Jared Powell:
Yeah, they're off the charts. Okay, good. I want to just run present to you a little clinical presentation or a little case study if you don't mind, about a, a differential diagnosis to, to help people try and differentiate between when it might be a bone stress injury or when it might just be soft tissue injury, for example. So let's go to the, the hip and the groin and let's say somebody comes in with sort of a vague ache in their hip slash groin and you are trying as a clinician trying to differentiate between is this e femoral femoral neck bone stress injury or is it some sort of adductor strain or sportsman's hernia or, or FAI presentation or, or something else. You should know, Rich, you've got FAI. When would you start to suspect that this is a bone stress injury rather than some other common athletic injury that can afflict the groin in the hip?
Rich Willy:
For me, I would, I would always look at the demographics of the person, the sport that they're in, if they're an endurance runner and they come in with anterior thigh pain that has a positive fader test, positive singly hop test. That's a bone stress injury until proven otherwise. I think I see what happen a lot is that it kind of masquerades as like hip flexor tightness or adductor tightness. It has a positive fader test, perhaps a positive favor. So a lot of times clinicians might mistakenly think that it is FAI and start treating it like that and then the athletes continue to run on and this bone stress injury is just continuing to develop. So we see that a lot with femoral neck bsis. We see it pubic ramus bsis because you'll get a lot of adductor spasming with them. So they get missed for, you know, for a long period of time. The other big one that gets missed is going to be sacral bsis because those will often mimic piriformis or gluteal deep gluteal syndrome SI joint pain. So those ones in the lumbopelvic region, they're very risky bsis and they get misdiagnosed for a long period of time. And so I look at the person from now if they're a soccer player, you know, I'm gonna be thinking probably more FAI because those are gonna be more the injury. Male soccer player's gonna be more the injury that they're gonna get rather than e femoral neck BSI.
Jared Powell:
And would they be more likely to experience like more consistent aching 24 7 type of pain that's unremitting and isn't sort of mechanically oriented or, or can a bone stress injury be sort of a mechanical experience as well where it hurts in a certain positions and and pain can be minimized by getting into a comfortable position? Yeah,
Rich Willy:
I, you know, I think that's, that's a not, not a bad way to kind of think about it is that when you have an athlete that is complaining of pain at at rest night, pain is classic example of, of a bonet stress injury pain that responds to loading, you know, or that comes on with that I think is you, you, you should start thinking like a bonet stress injury with 'em. So you know, some athletes experience like a warmup phenomenon with soft tissue injuries that we often don't see with bone chest injuries. But I would be careful with that. I would definitely not say that that's a rule. I've seen lots of cases clinically where that doesn't end up happening to be, you know, the case. Mm-Hmm So it's that pain at rest night pain that I would, I would pay really close attention to.
Rich Willy:
What you really worry about and you know, a lot of times, and this goes back to like when we're rehabbing our athletes, we really want to be thinking about they have a bone stress injury. They should not be experiencing any pain during their rehab. And there are two different types of pain that you can get from a bone stress injury. You can get pain in the moment that you're loading it and then you get this delayed pain the next day and the delayed pain the next day. What that is is that is a physiological response to too much loading for the bone. And the bone is responded by increasing periosteal edema or bone or bone marrow edema. And because of that you're increasing your symptoms. And so a lot of times athletes will say, well I get sore the next day after I do that. So it's probably not a BSI but that's actually the pain that you care the most about is the pain that it comes on 24 hours later. And that occurs just for when you're developing A BSI. But also during the rehab process too. You'll only be very, very, very sensitive to that like those reporting of symptoms. Awesome.
Jared Powell:
That's great. Thanks for that. Rich, Rich. Do all bone stress injuries hurt? So can you have an asymptomatic bone stress injury that you just unintentionally pick up on an MRI or my suspicion would be that they all kind of hurt because they're nociceptive, but are there cases where there's a mismatch between having a bone stress injury and the experience of pain?
Rich Willy:
There's a really great paper that was came at Stanford University and they, they did serial imaging of the men's basketball team for their serial MRIs of their, of their feet. And they found that they looked, they looked at them at the very beginning of the season and then they looked at them at the end of the season and of the men on the team they did this over a couple years and Adam ten four A was, was the first author on this paper, but I think he found that about three or four of the players had asymptomatic bone marrow edema and their metatarsals, I think that at least one of them had asymptomatic bone marrow edema in their navicular and a lot of them had asymptomatic bone marrow edema in their OIDs and then they followed them across the season. And some of those people, their bone marrow edema actually went away as the season went on or reduced.
Rich Willy:
More athletes had bone marrow edema by the end of the season. None of those athletes had symptoms. They're all asymptomatic. And so what that tells you is that imaging, we need to be careful with serial imaging, just like all things, right. Sounds should probably should sound quite familiar. Like low back pain and and what have you. Bone marrow edema that's asymptomatic is probably, you know, probably a good portion of people who have that are, it is probably just a a point of like normal bone remodeling. We probably shouldn't get too excited about it. And then I, I think it also speaks to the amount of loads that these athletes are experiencing during the season that they're actually getting this accumulation of bone marrow edema. Now what we don't know are athletes who then continue to go play on, you know, go like for instance in the US like for ncaa, you know at the women's level, you know for women they play all season, then they go through the NCAA tournament, they get drafted, they go right into the WNBA season and start playing right away. So they, a lot of these athletes end up playing in their, their rookie year like a full season. How many of those people go on on to develop A BSI if they can? Mm-Hmm. Because they're continuing to load is a, is a different question so, so anyway, so yeah you can most certainly have asymptomatic bone mar edema that is subclinical and because of that it does not qualify as a true bone stress injury. There's some evidence of that also in runners as well. So clinical presentation is really what matters the most in these athletes.
Jared Powell:
Yeah, good. And so we're using imaging as an adjunct to sort of corroborate somebody's pain experience, not just imaging everybody and trying to pick up bone marrow edema and then diagnosing them with a bone stress injury and then putting them into some management plan. Yeah,
Rich Willy:
Yeah, exactly. And so I think, I think just to kind of build on that just for a quick second and that's that like a lot of times again with professional sports we, we rush people off to get imaging very, very quickly and so someone has foot pain and we get them, you know, say they're an NBA player, they get brushed off to get an MRI on their foot and then they're like Oh look there's some bone marrow edema there, we've got a bone chest injury. But it's really important for the clinician to still do a complete clinical examination, make sure that it's not a soft tissue injury that's actually resulting in this pain rather and it's just a spurious finding of this bone marrow edema.
Jared Powell:
Love it. Thanks Rich. That's a question that's been nagging me for some time. I guess I could have looked it up and researched it but why would I do that when I could talk to you? So thanks for that. Yeah, I think that's gonna help a lot of people. Okay, let's let's briefly we've been skirting around it get into some principles or philosophy of managing a bone stress injury perhaps can we pick one sort of low risk bone stress injury and then perhaps a higher risk bone stress injury? And I'll let you pick which ones you wanna talk about. Maybe a tibia you can even do anterior and posterior whatever you like. And then what, what are some principles that you use to govern how you manage somebody with either of those bone stress injuries?
Rich Willy:
Yeah, so we'll do a posterior medial tibia since that's the most common BSI that people are gonna encounter. You can get 'em graded off M-R-I-M-R, I can be those, the gradients can be somewhat helpful. You only get imaging done for the diagnosis for those you don't need to repeat imaging to clear that athlete to go back to sport. So there's a clinical healing of a bonet stress injury and there's radiological evidence of healing. Those are not important on a, on a low risk BSI to get follow-up imaging. So we just follow them for their symptoms. There needs to be a period of deloading or relative deloading. We'll often put them on bilateral crutches where they're doing like partial weightbearing, maybe a boot. I tend not to use those 'cause it disrupts their gait quite a bit and we have 'em weight bear as tolerate, but the, they have a rule of no pain so they need to deload as much as possible so that and just enough so that they can reduce their pain.
Rich Willy:
We start introducing, as I mentioned earlier, you know, think about the muscle and the, the bone that's involved with it. I mentioned earlier that calf raises are quite a bit lower than their, their loads of running. So we start doing calf raises relatively early in their rehab process and of course we're looking for a pain response there. We start off with doing bilateral calf raises when they can tolerate it. Then we move into single leg and then we start adding some, some resistance to that. I really like the Smith machine. We're doing resistance training because they don't have to worry about balance. And then we start doing some hopping activities. Again, we start off, we always kinda do this model of bilateral first, then go to unilateral.
Jared Powell:
Are you working on strength at that stage to ward off the effects of the partial weight bearing so they don't lose strength or are you trying to increase their strength profile thinking that they need to get stronger to go back to their activity so as it's it's going to help their not get a recurrence?
Rich Willy:
It it is more maintenance. There's a collaborator of mine, Dr. Christie Pop, she has published this fantastic paper a couple years ago and she followed runners after a bone stress injury and did follow up DEXA scans on them and found that after the BSI is diagnosed that athletes lose bone density and not, not only do they lose bone density in their involved limb, they they lose it in their uninvolved limb as well. Mm-Hmm And they don't get back to baseline until six to eight months after the injury. And so what what we're trying to do is we're trying to prevent the loss of bone in the first six months after this injury or particularly the first 12 weeks because when the runner goes back to running is when their bone mass is at its lowest. And so while the injury might have healed overall bone mass is is that it's lowest.
Rich Willy:
And so it's not surprising that one outta three runners will have have a second bone stress injury in the first year after the initial BSI. So we start doing, so the calf raises are not, we're under no, no illusions. We're not strengthening the bone, we're just trying to prevent much loss of bone as possible. The other thing we have to worry about too are or other injuries they might get in the return to run process. So like an achilles synopses is classic example. So we're trying to prevent that from happening for the opposite leg. We start doing hopping exercises in that athlete pretty early, so almost on day one. So we'll have 'em stand in a doorway doing hopping activities there so they can maintain their, their bone mass and so, but yeah, the strengthening exercise is all they're there is just to maintain the muscle as much as possible because what we really care about is getting them to do some jumping activities and if you can maintain the muscle and keep it nice and strong, that means they can jump higher and better and that the bone forces are gonna be greater when we're doing plyometrics, which is what we kind of get into in the second half of the rehab programs.
Rich Willy:
We can get them back to get the back to running as as much as possible or as quickly as possible.
Jared Powell:
Cool. So you're doing some form of weightbearing is tolerated, when do you start to think about getting them off crutches and, and sort of walking around as normal and then when do you start thinking about getting back into running blah blah blah
Rich Willy:
Blah blah? Yeah, we get 'em off crutches as soon as they can tolerate it. Some athletes with like lower grade bsis, they don't ever need to be on crutches if they can walk without pain. But we, we try to get 'em off crutches as as soon as they can walk without pain. And of course as I mentioned earlier, we don't want them to have pain during walking but we also don't want them to have the pain later on in the day or the next day. So as long as they can do that, we get 'em off crutches. Once the athlete can start walking at that stage, we, you know, we, we know that we can get them quite a bit more active at that 'cause it basically when they're walking it's a single a calf raise. So if, if you can walk you can do a single a calf raise and if you can do a single a calf raise repetitively, that means you can do single leg calf raise with some sort of resistance.
Rich Willy:
So once the athlete is doing is walking without an assist device, we get 'em doing some heavy calf raises. Again, we're using pain as our guide. Ultimately what we wanted to be doing is some sort of plyometric and we start those off doing, doing like a bilateral counter movement jump. We do a counter movement jump with that. We'll start off with like 50% of effort. We're doing a counter movement jump because most of the forces for that jump are coming from your hip extensors and your knees. They're not, not coming from your plantar flexors. And so we'll start off doing, we'll have 'em land soft 'cause they're gonna be really using their hips and their knees a little bit and then we'll slowly increase or decrease the amount of time they're on the ground. So reduce that contact time. So we're shifting more and more and more load down to their plantar flexors and then from there we'll get them, we'll reverse this, we'll start back over, we'll go to single leg counter movement jump and then faster turn faster until they're doing basically a single leg pogo hop.
Jared Powell:
Awesome. So what's the value for you of apply metric as opposed to another form of resistance exercise, for example? Yeah,
Rich Willy:
So a couple ones. First bone responds, some bone's a little bit different than than tendon. Both those leg very high magnitude loads tendon as we know, responds very well to heavy slow resistance training because you're getting more strain, you're getting this change in this resting length bone does not respond very well to slow heavy lifting. So you want to be thinking about strengthening the bone differently than you wanna be thinking about strengthening the tendon. So bone responds the best to heavy, fast loading and that's where plyometrics come in. So plyometrics because you're loading the ground very, very heavy and you're also loading it very, very quickly, bending and twisting its bone at a very rapid rate and the bone is gonna, are gonna respond to that. You're getting a lot of osteogenic signaling that that's, it's actually occurring there. So heavy slow resistance, strain or calf raises while they can help provide you with the raw materials to be loading the bone, it's really the jumping that's actually gonna be getting your bones stronger.
Rich Willy:
So we try to get them into doing that really quite early, much earlier than we used to. And the other reason why I really like plyometrics, particularly from an injury prevention and a bone health standpoint is because when you're jumping, you're using your passive structures to store and release energy and your passive structures of course being like your connective tissues, tendons and so forth. So they don't require a lot of energy. And so because a lot of these endurance runners are so close to tipping the balance into a state of low energy availability, if we can do plyometrics with them, we know that the overall energy cost is quite low, but the benefit is gonna be quite good for them. And so plyometrics are typically what we program in for athletes, particularly our adolescent athletes. And we also really like plyometrics a lot for our athletes who have had a history of low energy availability who perhaps some energy deficit issues or like a history of disordered eating because we know that putting them, those athletes on a heavy slow resistance training might trigger them into restricting calories.
Jared Powell:
Love it. Beautiful. Well said Rich. Okay, let's move on to the higher risk bone stress injuries. How would you manage those?
Rich Willy:
Yeah, so those are, those are gonna be a little bit different. So as I mentioned earlier, the low risk bsis are always managed based off symptoms. The high risk bsis are always kind of managed based off where the site is and also the grade of the injury. And so when you're looking at a high risk injury, whether it's a grade four, which is gonna have cortical disruption or it's a grade two, those are always gonna be non-weight bearing initially. So we really wanna reduce loading on them and the reason is it's just very, very difficult to control the tensile loads on the bone and there needs to be a period of non-weight bearing for them. So femoral neck is a great example for those, you know, those are high risk bsis, we put their non-weight bearing for six weeks and then for them you do need to do repeat imaging on them.
Rich Willy:
So it's six weeks, they go back for a second MRI to make sure that there's some evidence of radiological evidence of healing and if there is then we can start putting them onto partial weight bearing from there and then gradually increase their weight bearing and discard crutches usually around 10 weeks or so and progress them from there. But yeah, you wanna be really, really careful with them and so you need to think about managing them quite a bit differently. And you really need to be thinking a lot about the muscle forces that are acting on the bone site bone stress injury site and know the consequences are quite high. We know that someone has e femoral neck BSI and they, they get full displacement of that. We know that over 50% of those athletes will develop avascular necrosis. If you've had surgery on a femoral neck, BSI, we know that that injury has the highest rate of non-return to sport, so it's about 50%.
Rich Willy:
So it's a pretty serious injury. So we wanna be very, very cautious and and really progress them quite slowly. So, but what what we do with them is we, we do the same thing femoral neck, we start off with doing, loading them bilaterally once we are, are able to do that. And the reason is is that single leg stance exercises put a lot of bending and twisting forces on the femoral neck. So we add those in last, we know the femur is the strongest in the sagittal plane for loading. So we start off loading in the sagittal plane and it's the weakest in the frontal and transverse plane. So we add those in last, but yeah, eventually we wanna start doing some hopping with those, those individuals we use the same paradigm. You just need to really slow things down quite a bit.
Jared Powell:
Yep. So once they get off, they get out of the high risk sort of initial phase and they, they had that repeat imaging and things are settling down, then it kind of starts to mimic what you're doing for, for the, for a lower risk bone stress injury perhaps. Yeah,
Rich Willy:
A hundred percent. And like anterior cortex to B-L-B-S-I, it's really pretty much the exact same progression as a medial one, but it's just a lot slower and those require surgery.
Jared Powell:
Well, I love it Rich mate, I'm very conscious of your time. We've asked you a thousand extra questions that I had put in the outline, so apologies for that. You've, you've handled it with absolute class, this has been a masterclass, a tool to force of bone stress injuries. Thanks so much for your time. Is there anything else that you want to add or do you think we've been quite comprehensive in our chat?
Rich Willy:
No, no, I think it's been great. It's been awesome chatting today Jared, so I appreciate it and Oh good. Yeah, thanks a lot. Yeah, this is one of my favorite topics to talk about, so no, thanks for having me
Jared Powell:
On. Fun. No problems. This, it's been an absolute treat for me. So Rich, where can people find you? You're, you have Montana running lab on Instagram, are you on Twitter at all? Do you have a website people can go to? Yeah,
Rich Willy:
Yeah, Instagram is probably the best place to follow me. And then we have, we have a website, so Montana running lab.com. Someone would like to reach out, just [email protected]. So we have a, have an online course goes over running injuries, probably about not quite half of it is on bone stress injuries. So if that's kind of population that you work with, then, then that's gonna be a good course for you to consider. So, but yeah, other than that, feel free to reach out to me mention the podcast and when you email and then I'll, I'll be sure to get back to you quickly.
Jared Powell:
Awesome. And you do a bit, do you travel for teaching? You mentioned you might be coming down under to Australia next year. Do you have anything else on the agenda? Yeah,
Rich Willy:
No, not, not right now. So I have some like private courses I have set up, so, but nothing really big. I don't, I don't tend to do a lot of courses just because I get get stuck in the research lab quite a bit. But yeah, I'll be coming to Australia I think, I think next August or September. So I love, I love coming, it's coming there and so it's, it's really wonderful. I've got a lot of friends there, so it's really awesome to come visit.
Jared Powell:
Awesome. If you're an Aussie and you're listening, I highly recommend it. Otherwise do Rich's online course. As you can tell, he's an absolute expert when it comes to this stuff and he communicates it with simplicity and coherence, which is hard to do, Rich. So again mate, thanks so much for coming on the show and I'll catch you soon. Alright, thank you. Thank you for listening to this episode of the Shoulder Physio podcast with Rich Willy. If you want more information about today's episode, check out our show [email protected]. If you like what you heard today, don't forget to follow and subscribe on your podcast player of choice and leave a rating or review. It really helps the show reach more people. Thanks for listening. I'll chat to you soon. The Shoulder Physio podcast would like to acknowledge that this episode was recorded from the lands of the Ang people. I also acknowledge the traditional custodians of the lands on which each of you are living, learning, and working from every day. I pay my respects to elders past, present, and emerging, and celebrate the diversity of Aboriginal and Torres Strait Islander peoples and their ongoing cultures and connections to the lands and waters of Australia.
