Welcome to the American Journal of Sports Medicine's webinar, presented in collaboration with Sports Health. Thank you for joining us. I am Christine Watt, Publishing Manager at AOSSM, and I will be the operator for the webinar today. There is CME available for this online activity. Here are the learning objectives and the disclosures for our faculty and organizers. At the conclusion of today's program, we ask that you complete a brief evaluation to collect CME for this activity. Details will be given at the end of the program and in an email to attendees. At this time, I would like to introduce our moderator, Dr. Tim Gabbitt. Dr. Gabbitt is an accomplished sports scientist and globally recognized performance consultants with PhDs in human physiology and applied sports science. He is also the associate editor for sports science for AOSSM's multidisciplinary journal, Sports Health. And with that, I'll turn the program over to Dr. Gabbitt. Thanks very much, Christine. I'm really excited to be the moderator for this session on injuries in runners. And we've got three really accomplished researchers and practitioners to present to you today. And I'll briefly introduce them. You have their bios, but I want to give you a little bit of information about them that may not be in their bios. Firstly, we have Dr. Brett Torresdale, who will present on training load and injuries. Brett is from the University of Utah. He has a special interest in training load and injuries in marathon runners. It's not his only interest, but it's something that he's done a lot of research in. He's also completed the New York City Marathon three times. And he's got some very unique stories about his approach to preparing for the New York City Marathon. Secondly, we have Dr. Adam Tenford from Harvard Medical School. And Dr. Tenford will present on soft tissue injuries, including the bane of the distance runner, the Achilles tendon or Achilles tendinopathies. So he'll present some information on conservative management of tendinopathies as well. And one of the things that you may not know about Dr. Tenford is he's a highly accomplished runner. A very, very, we would call him a very handy runner, very fast five and 10K time. And when I say fast, we're talking in the 13 minutes for 5Ks in the 28 minutes for 10Ks. And this is pre-supershoe era. So take another 10 seconds per mile off that time and you're getting pretty close to what Adam Tenford could run in the supershoes. And then finally, we have Dr. Barry Bowden, who is an orthopedic specialist from Maryland. He has a background as a competitor in soccer and track sprinting. And he'll be presenting on bone stress injuries. So without any further ado, what I'd like to do is set the scene a little bit for tonight's webinar with three very simple starting slides looking at training strategies for runners. And when I talk about training load, and we know that training load is extremely important for runners, it's how we get to good performances. But when we don't train appropriately, if we ramp up loads really quickly, or we throw excessive training loads at our athletes relative to their capacity, then it also increases the risk of injury. So training load is quite unique in that it can be protective against injury, or it could be predictive of injury. It could be the vehicle that could drive you towards injury or take you away from injury. But training load is not just a matter of the distance that you run, the miles that you run. What we look at with optimal loading with endurance athletes or with any athlete is, for example, if we're training for peak performance, we're loading progressively relative to that athlete's capacity. We want to load a little bit more than their current capacity. We're looking at tissue and system recovery. We're looking at the movement pattern of our athletes. We're making a subjective assessment of injury risk. We're looking at psychosocial resilience. Is our athlete ready for the fatigue that comes with high training loads? We're looking at the temporal stage of recovery and adaptation, and also the adaptive response to training. Now, this is when we have a healthy athlete. These are the things that we're looking for for optimal loading. But a lot of the time, as medical practitioners, you're going to have athletes that are presenting to you in a slightly different state. They're commonly going to be coming to you with musculoskeletal injury. Now, with injury or with pain, the thing I'd like you to keep in mind is that loading is still the same. The principles of loading are still the same. Rehab is simply training in the presence of injury or training in the presence of pain. The principles of loading are going to be exactly the same whether we're talking about peak performance or injury, except the words change a little bit. We're progressively loading based on the pain response. We're looking at tissue vulnerability. Again, we're looking at the movement pattern of our athlete. Are they fearful of going into certain ranges? We're looking at a subjective assessment of re-injury risk, the temporal stage of tissue healing, and the inflammatory response to rehab. Now, whether we're working with healthy athletes or injured athletes, these are the principles that we need to think about. That load is one thing, but load alone and using an arbitrary threshold or a 10% guide or a 10% rule is not enough. We still need to think about the response to load. Now, if the response is positive, given an appropriate amount of recovery time, then we can go back and we can load again. We can expose that tissue or system to a similar dose or a slightly higher dose than the one we just gave. But if the response is negative, then we've got a decision to make. We've got to adjust the program. Now, adjusting the program doesn't mean that we stop loading altogether, but it may mean that we need to regress load slightly before sensibly progressing again. So, whenever you're thinking about optimal loading for your athletes, bringing them back from injury or training for peak performance, we always need to consider the load response. The second thing I'd like to discuss is this interplay between local tissue and sport-specific loading. And the reason why this is important is because runners are obsessed with their Strava miles. It doesn't matter what runner you talk to, they're always interested in – they don't want to stop loading. They don't want to stop running because it'll impact their Strava miles. But load comes in a lot of different ways. Now, if we focus on this graph on the right and just look at the bottom left-hand corner when an athlete is injured, when an athlete is injured, local tissue capacity, the capacity of the injured tissue will fall to the basement. Because it's driven by pain, the pain response. When we're in pain, our local tissue capacity drops. And if we can't load that tissue in a local tissue way and we can't exercise at a local tissue level, then we're not going to be able to load in a sport-specific way either. So, as an example, if you injure your Achilles tendon, that's a local tissue injury, but it impacts sport-specific capacity because it impacts your ability to run. Now, the thing I'd like you to take away here is that there's an interplay between local tissue and sport-specific capacity, and both are important. Even though runners are obsessed by their sport-specific loads, the actual running loads, local tissue loading is critical. But in rehab, if you have a focus just on local tissue loading and you forget sport-specific capacity, then what that means is that there's a gap between being injured and being returned to full performance. So we want to try and bridge the gap where we can. We want to try and restore local tissue capacity, but have regular reminders of sport-specific loading. So we're trying to train around the injured tissue. If we can't run, can we get on a bike and do some circuits or some bike training or some unloaded running on an Alter-G treadmill or in a pool? We don't want – we've already got a local tissue problem. We don't want to create a second problem by allowing sport-specific capacity to fall to the basement. Equally, if you're healthy, don't simply overemphasize sport-specific loading. If you're a runner, you want to do your Strava miles, but make sure you're doing local tissue loading as well. So that involves strength training. It doesn't have to be bodybuilding training. You don't have to be in the gym for lots and lots of hours. Twenty minutes, two to three times a week is enough training to promote local tissue health. My rationale here is that if you can't do things at a low level, if you can't do single leg heel raises 20 times, then there's no way that you're prepared to run a half marathon or a full marathon. We want to build capacity in the local tissue so that it improves your ability to do the sport-specific loading. The best programs have a combination of both. So as a final principle that I'd like you to take away is if you're working with healthy athletes or if you have injured athletes, make sure you prioritize both tissue and system loading. Both of these things are going to give your athletes the best chances of coming back from injury and then staying healthy when they are in good condition. The second thing I'd like you to take away is that if you do need to unload your athletes due to a local tissue injury, then try your best to maintain global load capacity. Try and train around the injured tissue. The third point I'd like to take away, and we can go into more detail on this in question time, but different tissues have different recovery times. So when you load cartilage or tendons or bones or muscles, they all have different response times. So you need to consider the load response times and what is normal for different tissues and different systems. And then the final thing I'd like to emphasize again is to interpret training within an athlete monitoring framework, that yes, you're applying load, but you still need to consider the response. If the response is positive, go back and load again. If the response is negative, you might have to adjust the program before loading again. Okay, I'm going to stop there and I'm going to hand it over to Dr. Brett Torresdale now, who will spend a bit more time discussing training load and injuries. Thanks so much, Tim. And I'm going to be a part of this group today. I'm excited to share with you some of the work we're doing on trying to understand that connection between training load and injuries in runners. And I apologize in advance if my voice sounds a little funny. I came down with something over the weekend, but thankfully, hopefully I have enough time or gas in the tank for 10 minutes of talking. So let me jump into it here. Here are my disclosures. So what we're going to talk about today is running injury pathophysiology, what people have done previously to try to modify training to prevent injury, and what we're doing to try to understand how training load relates to injury among runners. And so we're thinking about how and why runners get injured. We think about, okay, what are the different kinds of running injuries? We have the overuse injuries, which are the majority of what we're talking about. Your tendinopathies, your IT band syndromes, things like that. And then you have your acute injuries, your ankle sprains. And so all of this is related to training load. There's the gradual onset of the overuse injury and then the sudden onset, like a pulled hamstring. And again, we'll talk about how this is related to training load. In terms of why people get injured beyond training load, there's a number of risk factors that have been identified, but a lot of these have been debated. There are some that are non-modifiable. I spend a lot of time thinking about what are the modifiable risk factors as we think about how to prevent injuries in runners. But really, I think training load is this active ingredient, so to speak, because without a training load, none of the other risk factors really aren't going to get you injured. So it's the training load that's the active ingredient, and everything else just affects how your body tolerates or your tissue capacity for that load or a change of load. And so we're thinking about just the load in itself, and then a change of load as being a risk factor. Acute injuries, those are going to be related to just your overall load, your exposure. Those overuse injuries, though, that's related to both your overall load and then specifically the change of load if that change is too fast. Here are the things that folks have done over the years in terms of interventions that have tried to change training load. A lot of it is just within this broader educational guidance for how to prevent injuries in runners or how to stay healthy as a runner. Unfortunately, so far, trying to modify training programs or training patterns have been ineffective at preventing injury. So after reviewing all of the literature on it, the determination that I came up with is not that training load doesn't matter in terms of injury prevention, but we just have to have a better understanding of how training is related to the development of injury. So first thing, where are there a lot of runners training and increasing their training load that could potentially be a subject, a population to study? Well, at the time, I was practicing at Hospital for Special Surgery on the Upper East Side of Manhattan, and every year, 50,000 runners would pass by the hospital just a block away as part of the New York City Marathon. And it turned out the hospital, I realized upon starting my practice there, is a sponsor of the marathon. So I started working through that partnership to do a study of New York City Marathon. So I first wanted to find out what's the study population, but then I thought about where are runners logging their training? And there are a lot of watches that are available, a lot of smartphone apps that people are using. So instead of trying to have runners do something specific for research, I thought maybe we should just tap into what runners are already doing in terms of tracking their training. So with that, we partnered with Strava, as Tim mentioned before, something that a lot of runners are focusing on. And then thought about, okay, how do most runners understand training load? Because if we come up with this complex metric of load, how are we going to communicate that to runners? Maybe there's a way that we could find these patterns of training in a language that runners use and be able to then educate them on how to modify their training using that language. So we thought, okay, load. In the U.S., people talk about that as mileage. Don't hear too many runners in my practice come in saying, well, my RPE on these three training sessions was X, Y, and Z, and I think that's why I got injured. They'll say, no, I increased my mileage from 20 to 30 or to 50, and now I'm injured. So we wanted to make sure that our research was focused on something that is accessible to the everyday runner. And then how do we think about change in load? At least what was out there at the time in the running world was the 10% rule. So don't run more than 10% of what you ran last week. Or the rule of twos, which is don't run too much too often or too hard. And the question is, like, what's too much? And I think the answer is typically, well, too much is however much you were running right before you got injured. And so that's not a really helpful or scientific way to measure training load in runners. So we partnered with a number of folks at Hospital for Special Surgery. These were the co-investigators in 2019. And we recruited runners of the New York City Marathon. We had them send out an email to all the registrants. And asked them to be a part of our study. We enrolled adults who were uninjured. We had them train, log their training using Strava. And then every four weeks in the 16 weeks leading up to the race, we surveyed them for injuries. We then used those established ways to measure that change in training load, one being the 10% rule. Another way to think about it in this acute chronic workload ratio lingo would be a seven-day, seven-day uncoupled rolling average would be your 10% rule. We also looked at the commonly used 728 coupled rolling average as our two ways to assess change in training load and associate that with injury. We enrolled over 700 runners. We had almost 50,000 runs logged during the 16 weeks of training. And what we were able to show in our multivariable regression was that the number of days that your acute chronic workload ratio was over 1.5, which is often cited threshold, was associated with subsequent injury. Not surprising the 10% rule wasn't associated with injury as many marathon training plans exceed that rule throughout the 16 weeks of training. So that's what we published after the 2019 marathon. We thought maybe we could do better. We could maybe go from association to prediction. And so we took another swing at it. And so in 2022, we did another observational study of the New York City marathon, similarly had them recruit on our behalf, emailing everyone who's registered. This time, instead of doing the associative analytics, we used a machine learning algorithm to do the predictive modeling for this. We trained the model on a random 80% of the runners, tested it on the remaining 20%, and used things like their baseline demographics to be predictors and prior week fatigue, happiness, and then their training information that they logged in Strava. We had 643 runners in that study. About half of them reported an injury at one point along the way. Most of them continued training despite that injury. And here's what we found for our training set. Here's how the model performed. We had an area under the curve of 0.79, which is pretty good. And then our test, our holdout subset, the area under the curve or the performance of that predictive model was 0.71, which is pretty good for a predictive model. Not great, but we thought, you know what, that's on 600 runners. We probably could do better, but let's dig into just exactly what were the predictive factors of injury in this data set. And so not surprisingly, that top predictive factor was history of running injury in the past 12 months. That doesn't surprise anyone. But thankfully the next few were modifiable. We can't change the past if you got injured in the past 12 months, but that 728 acute chronic workload ratio was predictive. Same with fatigue in the last week, use of orthotics, max daily distance of running in the past week. All were predictive factors. When we zoomed in on this 7-28 day acute chronic workload ratio, we this time didn't set any arbitrary cutoffs of 1.3 or 1.5. We just put it into the model and had the model figure out what is a meaningful or a predictive value for it. It's interesting that right about 1.3 to 1.4, there's a step up in terms of an increased risk of injury and then again at 2. We saw those two cutoffs. That led us to believe that there is some type of stepwise association with or predictive value of that measure. But like I said, if we're going to really get this model to be helpful or valuable to the broader running population, we're going to need a lot more numbers. We're going to need a better model and we're going to need a bigger boat. That's where thankfully we got grant funding from AMSSM and we assembled this team of AMSSM members and folks who are active in the running community involved in races and doing research. You'll recognize Adam as part of that group. It's been great to work with Adam on it. This was our mission to improve the health of runners and para-athletes by assessing the health and problems of this population, identifying factors contributing to injury, engaging the AMSSM membership, partnering with the running medicine researchers, scientists, and leveraging commonly used training monitoring technology because there's so much data that runners just collect on their own. We need to somehow use that to keep them healthy. This was the first aim was to conduct a modified Delphi study of what are the factors of their health and what things should we track over the course of an observational study of runners that are important. This is what Adam led. He did a great job with this large panel of experts to really distill so much that we want to know about runners and participants of endurance races into these key domains. We published that just this past month. It's available at open access, so check it out. Aim two, this is what we're getting at with collecting more data. This is not only a New York City observational study, but a national study in the US. We've thankfully partnered with Chicago, New York, LA, Seattle, Salt Lake City, and others to conduct this observational study of runners. It's open to anyone, but we just have these large races that have been big partners in recruitment. We're looking at runners, para-athletes, anyone training for a 10K distance or more, collecting their health data in REDCap, training data in Strava. And so we started data collection just this past summer. We're incentivizing them with a random drawing for an award, a gift card. And so far, we've enrolled a lot of, at this point, it's been over 3,000 participants of this study, a lot from Chicago, a lot from New York and Seattle. And we're excited for the spring marathon season to recruit even more. We've established different collaboration opportunities for folks, and we described the different ways for people to get involved who are wanting to not only take care of runners or be involved in races, but help collect the data and help analyze the data. So we have this set up and we're excited that even at AMS this next year, we have, I think we're at five abstracts with presenters from Stanford, Cleveland, Austin, New York, and Utah. So a collaborative effort, and it's been a lot of fun working with all these people. So that's where we're at. So we're going from association prediction, and then hopefully if we have our predictive model dialed in, we'll take that to the next step, which will be prescriptions. So using these predictive analytics to help guide runners so that we have an evidence-based adaptive training plan or program that will help runners avoid injury. So stay tuned for more work from the Runner Health Consortium. And thank you for the time. I'll hand it over to the next speaker. I'd now like to ask Adam to share his slides. He'll present on soft tissue injuries in runners. Thank you so much. And I think the talks by Tim and Brett really kind of set the stage for understanding some of the factors we're thinking about with the concern in this population with running-related injuries. And so I'm really going to be tackling soft tissue injuries, and then Barry will go next to talk more about bone stress injury. So again, my key disclosure is that I do a research study for Achilles tendinopathy with two groups, Federal Funding and Novus, but I won't be discussing any of the proprietary information related to that research. So what I want to do with this talk is to briefly describe the high burden of running-related injuries in these endurance athletes, particularly soft tissue injuries, looking at tendinopathy, particularly of the Achilles tendon, as well as plantar fasciitis, and then talk a little bit on the approach for management and considerations for different interventions that can be effective in treatment of these conditions. So first off, I think it's worth looking back on some of the earlier work, and this was from a systematic review performed by Alex Lopez, who we're really fortunate to have be part of our Delphi that we recently published, and he really kind of set some of our understanding for the overall incidence of injuries in those that are competing in marathon distance. You can see that medial tibial stress syndrome, which isn't a true bone pathology, but is really more of a peristitis, represents up to 20% annual incidence. Achilles tendinopathy and plantar fasciitis are the second and third most common, but as we go down the list, again, you see patellar tendinopathy, you see IT band syndrome, you see hamstring muscle injury. These are all highly represented as injuries, and the estimates for the annual incidence of running-related injuries have been ranging anywhere from 40 to 80% of athletes per year. So we know these injuries occur, the severity does vary, but it is worth noting that from our current understanding, a majority of these injuries are soft tissue related. So let's get into a few of the different conditions, and first off, the terminology is very important. Tendonitis, tendinosis, tendinopathy, these terms are oftentimes interchanged, but it's important to understand what they mean because understanding the underlying pathophysiology helps us to come up with more targeted treatments. So tendinopathy is really, you're never wrong to use that term because it really describes the spectrum of tendon disease and is thought to represent a failed healing response to the tissue, which results in pain stiffness and loss of function. So when we really get into some of the different conditions, very rarely are individuals seeing us in the early stages of a true itis. So a tendonitis would really be a primary active inflammatory process. Most of the time, by the time a reluctant runner is coming in to see a physician due to a number of different concerns, including fears that they're going to be told they can't continue their desired sport, they're oftentimes dealing with a more chronic condition. And the term tendinosis is oftentimes used to describe these more chronic forms of tendon injury, where the histopathological specimens really don't show a whole lot of inflammatory cells. There is probably a component of inflammation, but we're really thinking of this more as a failed healing response. And tendinopathy, again, really represents that full spectrum, thinking from the early stages of an inflammation to the more chronic disrepair of the tendon and disruption of normal type 1 and type 2 collagen to type 3 collagen. So when we get into risk factors, there's a number of different components. The components of training, the fact that they are doing the sport of running does put them at an elevated risk for certain soft tissue injuries. But there's a number of different risk factors. Older age has been shown to be a risk factor for developing tendon injury. It appears that male sex is a greater risk factor for Achilles tendinopathy. And a recent systematic review of looking at sex differences for injuries really concluded that the only conclusive injury more common in male runners is Achilles tendinopathy. And in female runners, it's bone stress injury. When we get into some of the other risk factors, there's a number of factors, including genetics or limb mechanics. And these aren't things that we can necessarily modify. When we get into the extrinsic risk factors, there's certainly the sport and the sport of running will certainly place athletes at an elevated risk for tendinopathies and soft tissue injuries. Differences with training, any change in footwear, whether that's going to a more minimalist footwear or potentially moving towards these performance footwear. There are thoughts that that footwear will modify injury risk. Loading characteristics. And then there are some culprit medications which we know in the sports medicine community to avoid, which include the antibiotic class of fluoroquinolones, particularly when combined with oral corticosteroid. So when we think about the initial strategies for management of tendinopathy, what we're really trying to do is get athletes to a state in which their pain has some initial control so that they can participate in structured rehabilitation with a progressive exercise program. So in the early stages, there is some degree of activity modification, which is required, but we'll get into how much you need to modify it. In Achilles tendinopathy, sometimes we'll use heel lifts or taping. Taping is a reasonable strategy for a number of other soft tissue injuries, whether it's rigid taping that provides a little bit of structural support or more of the kinesio taping, which may give kinesthetic feedback and help these athletes to feel better. Ice heat, honestly, it comes down to what the athlete, what feels better for them. But in general, you know, I use the concept of you warm up and you cool down when you do an exercise. So you're going to use, if you're going to use ice, you're going to use it after a run. And then anti-inflammatories are really controversial because, again, it's thought that the inflammatory milieu is part of the active tissue remodeling status. So going on an anti-inflammatory medication when you're really trying to achieve analgesic benefits, there have been editorials within the past decade suggesting we should really be moving more towards the use of acetaminophen and other other medications that are not in the non-steroidal anti-inflammatory medication group. We need to think also for these runners about what are their biomechanical and strength deficits. And it's not always localized at the tendon level, but it's really thinking through the full biomechanics of running. And if we really break down our sport as much as I love it, it's a series of single leg squats, hops and leanings without falling down. And so if you can really look at that structurally for a runner, when you're evaluating them, oftentimes you can identify not only the challenges they may have doing a heel raise with Achilles tendinopathy, but doing some simple things like balancing on one foot or performing a single leg squat without seeing that lumbopelvic instability that we oftentimes have as athletes. And then we want to think about other strategies that can work with the athlete. And really, we have to think about the time of their training. Are they in a position where they can do some load management or in some of the more extreme cases of the use of orthobiologics, have a period of time for protected status to allow those cell-based treatments to work, such as platelet-rich plasma. Very rarely, though, is surgery recommended for tendinopathy unless it's a more advanced full thickness tear or there's other clear advanced structural deformities. But again, the good news is that most of the time these can be managed through non-surgical techniques. Now, there's always the question that athletes have. They've tried physical therapy in the past and it's always a question like, does this actually work? And we did a systematic review on this a number of years ago, looking at different strategies with outcomes at the three-month mark and then outcomes that go out further to up to 12 months. And the systematic review with network meta-analysis allows for us to compare different clinical trials that used an outcome of interest called the VISA-A. And that's an eight-item questionnaire scored from zero to 100, which helps you to understand symptom severity for the Achilles tendon. Really, what we found in this review, which I'll share with you in a moment, is that exercises are effective. And the initial exercise program, which really changed our load management strategies and is applied to a number of different tendon injuries, is the Alfredson Protocol. And this was based on a study in 1998, where 15 runners who had chronic mid-portion Achilles tendinopathy who would have typically had surgery were recommended to do progressive loading program of heel raises off a stair, and to do three by 15 repetitions with the knee bent and the knee straight twice a day. And then as that got easier to put on a weighted backpack and to continue to load and to push through the pain. And what was found in that initial investigation is that 15 of 15 runners were able to return to running with more minimal pain. This really revolutionized how we approach tendinopathy. And it's oftentimes applied to a number of different tendon injuries. Now, there have been some controversy on whether we achieve 100% success. And I think those that commonly see athletes and put them through an eccentric loading program recognize that we don't always have 100% success rate for the Achilles tendon. It's been estimated probably closer to 60% of individuals with satisfactory results, and then a residual group that are looking for benefits. But the goal of the loading is really the concept that mechanical loading, particularly applying force under lengthening, may provide the right mechanical stimuli to reorganize the diseased collagen making up the tendon and to disrupt neovascularization, which has been proposed to be one of the mechanisms associated with tendon pain. When we did the systematic review, though, and we pulled the different data, we do find in the short term, we don't necessarily see success of eccentric exercises compared to other groups, where there did seem to be a signal in the short term was a high volume injection of corticosteroid combined with eccentric exercises seem to lead to better initial results, with those results starting to fade, but still seen as significant out to the one year mark. Now, why I don't recommend this for runners is that we do know that corticosteroids can suppress collagen turnover even years later. So it's not, it's not my recommended treatment, but from pooled analysis, there is a signal. And there was also a very strong result in an acupuncture study, again, in a non athlete population of receiving acupuncture three times per week for six weeks, which again, you know, it's a very labor intensive treatment option. When we get out to the longer term in this three to 12 months, what we see is that the wait and see approach will lead to functional decrement. And that's why it's, it's actually considered unethical to, to run a clinical trial at this point, where you have a true control group, which is not given an exercise program, because doing anything compared to wait and see will lead to better outcomes. What we see here, though, in this longer term outcome is that the combination of shockwave therapy with eccentric exercises had one of the strongest signals for functional improvement. Now, why do we think shockwave can work? Well, for Achilles tendinopathy, there have been a number of studies, we recognize that it works better for non-insertional versus insertional, and the presence of a Hagelin's deformity is thought to be a less favorable prognosis. There's one study early on from 2005 by Costa in older females, 65 and 67 years of age that weren't athletes, that did sustain tendon rupture, but across all clinical trials for treatment of tendinopathy with shockwave, those are the two major adverse outcomes across all clinical trials, not just in the Achilles tendon, but other tendons. The advantages that I see with shockwave and why it's, it's something that has a lot of enthusiasm in runners and other active populations, is that it's a non-invasive treatment with a largely favorable side effect profile, which oftentimes allows for some degree of activity during treatment. Now, when we think about shockwave or other procedures, we still need to stick to the tenets of an exercise program, and then the consideration of how much can you run, and the initial study by Svivornakal looking at, looking at Achilles tendinopathy, and this was, was earlier in, and I believe AJSM over a decade ago, was she took two groups of athletes. One group was told you can run as long as you keep your pain below five out of ten, but you have to do my exercise program every day. The other group was told you're not allowed to run for the first six weeks, and you're only allowed to do the exercise program. Both groups were followed out to a year, and about 80 percent of individuals had functional improvements of about 32 points on average on the visa A scale, but they did equally well, which means that the, the process of telling everyone when you have an Achilles tendon injury or tendinopathy in general, that you're not allowed to exercise, that is outdated information. Now this, this scale has been further refined by Svivornakal and, and Crosley to a green-yellow-red zone, and this has been validated for the Achilles tendon, and there is some emerging literature suggesting it can be used in other soft tissue injuries. So the goal is that we, we give, we give the runner this scale from zero to ten, and zero to two out of ten pain during or after an activity is, is called the green zone. That is the desirable zone of pain that an individual can experience, and it's thought that that's not causing any increased demand to the tissue. Yellow zone is pain that is in the three, four, or approaching five out of ten range, and again, that's an acceptable zone of pain. So having that type of pain once or twice a week, you know, and for a runner that might be after longer runs or, or more exertion, it doesn't necessarily mean that they're going to tip the tendon back into further excessive inflammation and disrepair. However, athletes and runners should be encouraged not to exercise with pain above five out of ten, And the theory is that pain that's above that threshold may be leading to excessive soft tissue damage and inflammation, which is going to further delay the soft tissue healing. So we really use this green-yellow-red zone model for soft tissue management. And while this is invalidated for the next condition I'll discuss of plantar fasciopathy, I do like to apply this for all soft tissue injuries. So let's get into plantar fasciitis briefly, a degenerative condition of the soft tissue that overlies the plantar aspect of the bone. It's a really impressive structure, which I believe my surgical colleagues have moved away from doing fascial releases because what we recognize is that this fascia extends along the full length of the plantar aspect of the foot out to the five, the five rays of the foot. It helps to work for both static and dynamic stabilization of the foot. It does have some continuity to the Achilles tendon. So I like to joke with some of my patients, a close cousin of Achilles tendinopathy is plantar fasciopathy. I'm sure we've all seen this, but there is anatomical explanations for that. And then we have to think about the fact that there are a number of layers of muscles to make up the medial arch of the foot that also play a role in the dynamic stress that the plantar fascia takes on with each stage of the gait cycle. So the key features we see with plantar fasciitis is pain localized to the heel, oftentimes with associated morning stiffness. We oftentimes will identify pain over the medial calcaneal tubercle, and there may be pain brought on through the medial longitudinal arch with careful palpation or with performing the windlass test. The management for this in brief is very similar to tendinopathy. We're trying to identify ways to get the fascia to be less painful so we can do the exercise program. So night splints are considered. I oftentimes will reserve those for individuals that have a lot of first morning step pain, and the theory is that we oftentimes sleep with our feet in equinovarus, and so applying a night splint will help to keep the foot from being in that relaxed state where it takes on a lot of increased tension with those first morning steps. I rarely recommend long-term use of foot orthosis, and as Brett showed, orthotics may actually be associated with injury, but regardless of your thought process with orthotics, it's worth recognizing this is really a passive way of stabilizing the foot, and it does not inherently address the soft tissue impairments or the strength deficits which are causing the plantar fascia to take on the abnormal stress, so there's really been a move towards more the use of temporary orthosis. I'm also a huge fan of low-dye taping, which is a rigid taping that can oftentimes provide some support of the arch, and I do think a foot core progression is helpful. You can consider other interventions. Corticosteroid injection is one that's commonly used, although a Cochrane review article has concluded that there is a low level of evidence for one month of pain relief with corticosteroid injection. In a separate review that we performed in the journal Life, it does appear that if you are going to do a corticosteroid injection, doing it under ultrasound guidance is more likely to lead to better relief than it is if you do it palpation guided, but the other larger meta analyses comparing corticosteroid to platelet-rich plasma or corticosteroid injection to shock wave show that both platelet-rich plasma and shock wave therapy outperform a corticosteroid injection at three months, and in some cases you can even consider different biological mechanisms of action and complementary treatment with shock wave and platelet-rich plasma to target more advanced cases of soft tissue injury. We published the first reports of this in German Journal of Sports Medicine. The reference is there, but I do think there's going to be a lot of interesting data that's going to come out in the coming years looking at different ways to stimulate localized soft tissue healing. For those not familiar with the foot core, this is really a tenant for management of soft tissue injuries in the foot and ankle, whereas you're going to hear from Barry, you know, management of the number of different bone stress injuries that can happen in the foot and ankle, especially if someone has been immobilized. We really need to think about the fact that the foot, similar to the lumbar spine, has an active and passive subsystem along with neural control mechanisms, and we don't always address this. Even if someone's been immobilized for a few weeks, there can be intrinsic foot weakness, so we don't always fully regain, or high mobility deficit, so I believe any runner who has an injury could probably benefit from meeting with a physical therapist. On the right comes from a technique that we published on Tibialis Posterior Tendinopathy, combining shockwave and foot core exercises, but a couple of key exercises include foot doming, as represented in panel A, which is really raising the medial arch of the foot a few millimeters and really trying to engage those four layers of muscles to make up the medial longitudinal arch. The second is toe yoga, which we also refer to as toga, and it's being able to raise your great toe while keeping your lesser toes on the ground and alternating. The third is toe spreads, sometimes done with toe spacers to get a little bit of kinesthetic feedback, but it's really working on the foot intrinsic strengthening, which can be helpful for a soft tissue injury such as plantar fasciitis. So in summary, these soft tissue injuries, I hope you come away from this talk recognizing they are common, that effective management really is thinking through the multifactorial nature of them to develop a comprehensive approach. The mainstay is physical therapy with an exercise program and load management, and there are a number of interventions, and I favor shockwave, but also non-steroid-based treatments given this population to consider in more refractory cases. So thank you for your attention. Our last presenter is Dr. Barry Bowden, who will present on bone stress injuries. Hey, great. Thanks so much, Tim. Appreciate the invitation to speak tonight. I am going to be talking about bone stress injuries, and I have no disclosures pertaining to this talk. Bone stress injuries are overuse injuries of the bone. They are caused by repetitive sub-threshold loading. There is an imbalance between micro damage, which occurs every time an athlete runs, and the repair process that occurs during rest periods between exercise sessions. And these injuries are most common in the lower extremities because they are weight-bearing bones. Okay, the incidence of bone stress injuries in the general athletic population is less than 1%. However, in runners, it can be as high as 15% to 20%. And in a review of 320 athletes with a stress fracture, the most common location was the tibia, representing approximately 50% of the injuries. And you can see a subtle stress fracture in the x-ray to the right, not so subtle on the MRI where you can see the edema. The next most common bone stress injury is the tarsals, 25%, followed by the metatarsals, the femur, and the fibula. And running was found to be the most common activity causing these stress injuries. In 16% of cases, there was a bilateral stress fracture. So really important to take a good history and physical. The history includes typically an abrupt increase in the intensity or the duration of exercise. Athletes usually have pain with activity, especially weight-bearing, and the pain is often relieved with rest. On examination, they often have point tenderness over the involved bone, especially if it's superficial, but less so if it's a deep bone. Risk factors for bone stress injuries being a female athlete, distance runners, military recruits having oligo or amenorrhea, nutritional deficiencies, hormonal deficiencies, metabolic bone disorders, and a history of a previous bone stress injury. Now, the term female athlete triad has been replaced by the newer term relative energy deficiency in sports or REDS. And this condition is a failure to adequately increase the food intake to balance increases in caloric expenditure. And the causes may be food restriction by the athlete, food availability constraints, or a disordered eating behavior. And this condition results in hypothalamic hypogonadism with decreased estrogen leading to amenorrhea and decreased testosterone. So the best way to think about this is the body recognizes that the athlete is malnourished, is basically going to shut down the reproductive system so you can't get, the female athlete cannot get pregnant. These athletes have a low body weight, low BMI, and a low body fat percentage. So let's review the classification systems. And there are really two commonly used classification systems. One is high risk versus low risk, depending on the location of the stress injury. High risk bone stress injuries occur in the femoral neck on the tension side, as can be seen in this x-ray. They occur in the patella, the anterior cortex of the tibia, medial malleolus, the talus, the tarsal and the vicular, the fifth metatarsal, the base of the second metatarsal, and the great toe sesamoids. And the reason why these are high risk is because the injury usually occurs on the tension side of the bone, making it harder to heal. It's often a hypovascular area of bone, so there's insufficient blood supply. And these injuries, it's more likely to need, they're more likely to need an MRI to evaluate the stage so that proper treatment can be instituted. Early diagnosis, of course, is critical to prevent fracture or non-union. Low risk bone stress injuries occur in the upper extremity to include the clavicle, scapula, humerus, olecranon, ulna, radius, scaphoid, and the metacarpals. They can occur in the ribs, especially in rowers. They occur in the pars interarticularis, in the lumbar spine, especially in gymnasts. They can occur in the pelvis, especially the sacrum and the pubic rami, the femoral neck on the compression side. And we'll talk a little bit more about that in just a minute. The proximal tibia, the calcaneus and the metatarsal shaft. And this is an X-ray of a healing third metatarsal shaft stress injury. The second classification bases these injuries on the structural changes. And it's based on MRI findings. It's a five tier grading system that describes the extent of the structural failure. So for grade one injuries, the athlete is going to be asymptomatic, but a stress reaction is going to be present on imaging. Grade two, the athlete is going to be experiencing pain, but there will be no fracture line. Grade three, there's a non-displaced fracture line. Grade four has a displaced fracture and grade five is a non-union. And what I would recommend is combining these two classification systems. I think that this classification system is good for identifying the stage, but it's also important to know the location of whether it's a high risk or a low risk injury. We often start our imaging with plain films, but these films can be negative at first. This X-ray of the ankle does not show any obvious stress fractures, but these X-rays can be positive two to three weeks after the onset of symptoms. And you can see in the lower X-ray, the healing stress fracture of the fibula. Findings that often appear on a delayed basis in cortical bone, periosteal reaction, cortical lucency, a fracture line. For cancellous bone, the findings are more subtle and they include a band-like area of focal sclerosis without periosteal reaction. Advanced imaging may be necessary to include MRI, CAT scan, or a bone scan with MRI being most frequently used these days and should have a low threshold to use MRI for high risk locations, especially the femoral neck or tarsal navicular stress injuries. So treatment for these injuries is determined based on the stage. And again, whether it's a low risk or a high risk injury, this X-ray is an example of an inferior pubic rami stress injury that is healing. And for the low risk bone stress injuries, these can typically be treated with relative rest. They may need non-weight bearing and or immobilization. Healing usually occurs pretty rapidly in two to six weeks. And once the symptoms subside, these athletes can gradually return to exercise, starting with low impact activities first, such as biking or swimming, and then gradually returning to running. For the high risk stress fractures, these often require non-weight bearing with immobilization if they're caught early. But many of these injuries often require surgery, especially if it's a chronic injury or a high level athlete that wants to get back to activity as soon as possible without taking the chance that immobilization may not correct the problem. So this is an example of an athlete, a gymnast who had a medial malleolus stress fracture, treated her with a cast immobilization for two months, did not heal. So finally ended up fixing it surgically, and it did heal pretty rapidly. What's also really critical when you're treating these injuries is always think about prevention. You want to think about ways to prevent the next stress injury. You don't want to just get the athlete to heal, but you want to make sure that you identify and correct any predisposing factors when possible. And this is a very busy slide, but we're developing an algorithm submitted to Sports Health that's going to describe the different stages and what to do at each stage as far as the workup goes. But always think about training errors. Those are the most common errors, and what can be corrected. Nutritional errors, metabolic problems. Many of these athletes are anemic. They may have a low iron. They may have low vitamin D levels. Endocrine consult may be indicated, especially if the athlete has a high risk injury, a delayed union, or recurrent injuries. So let's review some specific bone stress injuries, starting with the femoral neck stress fractures. And these injuries typically start, there's an insidious onset of groin pain. It's very critical to have a high index of suspicion for these injuries. They're often negative on x-ray. This x-ray did not show any evidence of a stress injury. So have a low threshold to obtain an MRI. You can see on the MRI, the stress injury, the fracture at the inferior aspect of the femoral neck with the surrounding edema. These injuries can usually be treated non-operatively with six weeks of crutches, and then a gradual return to full activity at three months. However, recent data has shown that these injuries may not be as benign as once thought. This x-ray shows an athlete that had a compression-sided femoral neck fracture, had a fall, and it fractured completely. Operative fixation should be considered if the fracture is greater than 50% of the width of the femoral neck, or if the fracture is less than 50% of the width of the femoral neck, but there's a hip effusion present. So the presence of a hip effusion is associated with an eight times increased risk of progression of these injuries. And this particular athlete did require open reduction and internal fixation. The tension-sided femoral neck stress fractures, initial treatment if it's non-displaced is usually prophylactic pinning with three cannulated screws. The reason for this is because untreated tension-sided stress injuries can lead to nonunion, malunion, and even avascular necrosis. If it's a displaced injury, these are treated with open reduction and internal fixation. However, if these injuries are caught early, new data also reveals that non-operative treatment may be successful if there's no fracture line and no joint effusion on MRI. Proximal tibia stress injuries are considered low risk. They're very common in runners. They should be included in the differential of any athlete with medial-sided knee pain, with possible medial meniscus tear or osteoarthritis. The x-ray to the top on the left did not show the stress injury, but the MRI clearly shows a fracture line with surrounding edema. And in the lower x-ray, you can see the band-like sclerosis showing healing bone. So again, they're often negative on x-rays. These can be successfully treated with a four to six week period of rest. The anterior cortex of the tibia stress fractures, these are high risk stress injuries. They occur in the tension side of the bone. It's the hypovascular area. The x-rays may show the dreaded black line as can be seen here on this x-ray. Initial non-operative treatment with non-weight bearing and immobilization may be successful if it's caught early, but it can take a long time to heal. And there is a high rate of complication. So surgical intervention is often indicated by either with a tension band plating or an intramedullary rod. And beware of the asymptomatic anterior cortex stress injury. Some of these injuries become non-unions and the athletes do not have pain. We reported a series of several athletes that were asymptomatic and had a complete fracture during competition, which required surgical intervention. The fifth metatarsal occurs on the cortical aspect of the fifth metatarsal, which tends to heal at a slower rate than the cancellous bone. At the more proximal aspect, it's a hypovascular area. Many of these athletes have a cavovarous foot alignment. Non-operative treatment can be indicated if it's caught early, but there is a high risk of non-union. So surgical fixation with either intramedullary screw or a plate is often indicated. The tarsal and navicular stress injuries are also high risk. They occur in the tension side of the bone. They usually start in the dorsal cortex, usually in the middle third of the bone, which is the hypovascular area. It's important when taking x-rays to obtain an extra oblique x-ray because the navicular sits at a 45 degree internally rotated position. So in order to get a 90 degree angle at the navicular, you really want to externally rotate the foot. However, if this is suspected and it's negative on MRI, patient has pain in the midfoot, they're training for a marathon, get the MRI, and you can see on the right here the stress edema consistent with the injury. A non-operative treatment has been reported to be successful if it's caught early, past immobilization and non-weight bearing, and surgery is indicated if it's a chronic injury, any displacement, or a high-level athlete that wants to return to activity as soon as possible. So in conclusion, the key with these injuries is early diagnosis, especially for the high risk stress injuries, have a high index of suspicion based on the history and the location of the pain, and it's also critical to always be thinking about what can be done to prevent the next bone stress injury, address the risk factors, the training errors, the nutritional disorders, and any metabolic conditions. So thank you very much for your attention, and I'll turn it back to Tim.

sports medicine

runner injuries

training load

injury prevention

tendinopathies

bone stress injuries

load management

exercise programs

technology in sports

athlete health