About Travis Pollen

Travis Pollen is a Philadelphia-based personal trainer and Ph.D. in Rehabilitation Sciences. He also holds a master’s degree in Biomechanics and Movement Science. His research interests focus on movement screening, training load, and assessing risk of injury for athletes.

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Show Notes

To follow Travis on IG click here @fitness_pollenator

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Assessing risk of injury.

Is it possible? If so, what even consists of an injury?

About This Episode

Travis and Kathryn talk about injury risk factors, whether or not assessments are effective, how to define an injury and active vs. passive range of motion. Travis critiques one of the more popular assessments and shares insights from his rehab science studies. Kathryn brings up the idea of alignment, and Travis talks about how alignment isn’t what we think it is. They also discuss the current theories about closing the gap between active and passive range and how important this actually is.

This interview will encourage you to critically evaluate what you hear about mobility, injuries, and risk factors. This is a really important discussion to be having right now.

Travis speaking assessing risk factor for injury in swimming

Podcast Transcription

Kathryn: 00:03:56

All right Travis welcome to the podcast.

Travis Pollen: Thank you for having me, Kathryn.

Kathryn: Yeah, my pleasure. I’ve been following you online for a little while and if folks are not following you especially on Instagram they should because you make all these wonderful posts. I have picked out a few today that I want to ask you more about. But in case people don’t follow you online or they don’t know who you are. Do you want to take a few minutes and just tell people a little bit about your background and the type of work that you do?

Travis Pollen: 00:04:22

Yes. So I had just completed my Ph.D. and rehabilitation sciences at Drexel University in Philadelphia. So I am a researcher and I’m also a personal trainer. I have been certified since 2013 and I’ve worked in commercial gyms I’ve worked in homes, I worked in some trading studios, I’ve worked online. So that’s what I’m doing now. A combination of research and personal training but rewind sort of to how I got into all this.

00:04:57

Going way back, I was born missing my left my so I am effectively and above the knee amputee. I guess my rehabilitation journey but also my athletic and training journey started in high school when I joined the high school swim team. Long story short I had a seven-year swimming career where I continued swimming in college.

I tried out for the Paralympics in 2012 and all of that sort of led me to personal training because when I finished my undergrad degree, my undergrad degree was in physics. I realized that I didn’t want to pursue higher education or employment really in the realm of physics but I loved to exercise.

I loved all of the stuff that I was doing outside the pool from a strength training standpoint to get me better in the water. So I decided I would become a personal trainer and I did that for a little while before then going back and getting a master’s degree in biomechanics and movement science. Which is pretty much like the perfect hybrid of exercise and physics. Because it’s the mechanics of human movement.

So that was a really good fit for me and it sort of positioned me then to go and pursue the Ph.D. in rehabilitation sciences which is sort of the research side of physical therapy for my dissertation. I looked at risk factors for injury and swimmers. I’m really interested in the way that movement affects injury risk and the way that training load affects injury risk as well as the psychosocial components of an injury risk.

00:06:45

So I did all that for my dissertation and now I am looking for faculty jobs but there’s not a whole lot of openings right now. As you mentioned I’ve been getting more consistent with my Instagram posting. I’m just trying to really focus on bridging the gap between research and practice. Because I feel like there was a lot of stuff that is really important in the research that isn’t known about in practice whether that’s personal trading or rehabilitation.

There’s just a big gap. Then also bridging the gap between rehabilitation and performance. One of the things that I observed through the last few years where I was very involved with physical therapists, collaborating with them, and also athletic trainers and sports medicine and strength conditioning coaches was that there was a bit of a communication barrier between each of those professions. So just trying to figure out how to harmonize those worlds a little bit better is sort of where I see myself in the big picture of things.

00:07:49

And maybe for your listeners sort of how I found you and some of the more general movement practices outside of just a training setting is that I’ve actually been a yoga student since I was 15. So half of my life. I’ve done it sporadically at some times and work consistently at other times but lately or prior to the pandemic I was taking a weekly yoga class at my rock climbing gym. Rock climbing and sort of the main sport that I’m interested in right now.

But I’ve used yoga as a way to facilitate mindfulness and relaxation and kind of balance out the intense training that I was doing in swimming while I was doing that. Now I just continue to enjoy it because I see a lot of parallels between what we do from a training standpoint and then what yoga teachers and yoga students talk about and think about in the way that they look at movement.

00:08:47

And so I have been collaborating a lot lately with Jenny Rawlings who your listeners might be familiar with. That’s been really an incredible experience to learn from her and learn more about the movement and Science of Yoga and kind of contribute my research expertise to some of the work that she does.

Kathryn: 00:09:04

That’s awesome. Actually didn’t know that you were a yoga practitioner. When I follow you online I see so much like strength training and stuff like that and that’s so interesting to hear that you’ve been practicing yoga for all these years as well. I feel like this will be even more helpful for the people who are listening.

Travis Pollen: I hope so. Also, I am definitely not an expert by any stretch of the imagination but I think that having done it for so long. You know on a recreational basis I can at least speak the language of yogis a little bit.

Kathryn: 00:09:39

Yeah totally. So what is the difference between a Ph.D. in rehab science and a Doctor of physical therapy?

Travis Pollen: That is a great question and something that as I’ve been applying for jobs, I understand it but, trying to convey what a Ph.D. in rehabilitation is on my resume and my cover letter is tough. It’s not like you’re an exercise scientist or a kinesiologist or a physiologist. So it’s kind of a vague term. But I can start by saying a doctorate in physical therapy is a clinical degree that you get over about three years.

00:10:17

It involves a lot of classes and then a lot of clinical rotations and that degree prepares you to be a practicing clinician. So practicing physical therapists or physiotherapists as other countries call it. I am not a clinician or a physical therapist. You could say my in the trench experiences as a personal trainer and the research that I’ve done and the degree that I’ve done has been a doctor of philosophy and rehabilitation sciences.

And so that is more of the research side of physical therapy. And so I’ve been involved in research on risk factors for injury in competitive swimmers. I’ve looked at some testing for anterior cruciate ligament return to play. So that’s kind of the two avenues that I’ve been pursuing during in the last four years of my doctorate.

00:11:09

And so basically my degree prepares me to be a teacher a professor at the University and to engage in teaching undergraduate or graduate students as well as conducting research. It doesn’t allow me to be a practicing physical therapist. And so the confusing thing I guess when you look at my resume is that my degree is in rehabilitation science yet I’m not a clinician.

So my niche I guess in teaching would be that I could teach statistics, research methods, exercise biomechanics, like exercise prescription, kinesiology, I could teach evidence based practice. Like helping future physical therapists better understand how to critically appraise research.

00:11:56

The challenge though is that most universities with physical therapy programs are looking for clinicians to teach their clinical classes and maybe they have one person who does those other classes that would sort of fall into my area of expertise.
That’s my challenge right now. I have this PhD but where would be the best fit for me? Because the other thing that I could do would be to teach exercise science, at an undergraduate level.

But my background isn’t actually in exercise science. So I’ve only taken one anatomy and physiology classes and it was at the undergrad level.I’m really not equipped to teach those sorts of classes. I kind of have this broad area of expertise but it doesn’t fit exactly the shape or the norm of what a lot of universities are looking for. It’s been an interesting challenge for me so far and I think we’ll be moving forward as I continue job hunting.

Kathryn: 00:12:49

Yeah, it’s so interesting to hear what people end up doing with these specialized educations.

Travis Pollen: I think the normal trajectory is you do your PhD then maybe you do a postdoc which is one to three years maybe of further research training and grant writing. Then you go and get a faculty position. But I don’t want to deal with all the grant writing. I’m interested in research but I want to do that on the side and kind of focus on teaching if I do go the academic route.

But then there’s this other side of me where I really like working with people in person and I’d like to continue personal training. But I’m a little bit overqualified as a personal trainer with a Ph.D. But at the same time, I really do see there is a need for trainers with advanced research skills to help other trainers learn and just be a really great asset to clients. So I’m happy doing that for now even if I can’t find my dream academic position for how long.

Kathryn: 00:13:48

I want to ask you about injury risk and I know you said you were studying injury risk in swimmers. So if we’re not going to talk specifically about swimmers, what are some of the big factors you’re looking at from a more general injury risk perspective?

Travis Pollen: Yeah. So I did my research on swimmers. I was a swimmer obviously but my interest in athletic injury, mechanisms, and ideology focused on swimmers but it applies more generally to athletes. Also to anybody who is engaging in physical activity. So the biggest risk factor, as I’m sure you’re familiar with and many of the listeners might be, is having a previous injury.

00:14:31

That has been shown in a variety of sports. I found the same thing in my research with swimmers and it isn’t just necessarily if you’ve had a previous shoulder injury then you’re more at risk for another shoulder injury. You could have a previous shoulder injury and be more risk for an injury to the other shoulder or to the hip.

So it can that you’re more at risk for another shoulder injury but it can also just apply more generally. Once you’ve had one injury you’re more likely to have another. That’s sort of the biggest and best thing that we know right now. Or the thing that we know most consistently is that if we’re trying to identify people who are at increased risk of injury, all we have to do is ask them if they’ve had a previous one.

00:15:13

It’s kind of really simple on the one hand but it’s also complicated because now that you’ve had a previous injury we call that a non-modifiable risk factor because you can’t change the fact that you’ve had a previous injury.

You can make sure that that injury has been fully rehabilitated and that you’ve fully recovered compared to your opposite side. Which is often a common competitor from a strength or range of motion standpoint. Or you can look at if you have good normative data for a given test. Let’s say if you’ve had a low back injury and you’re focusing on building back up your endurance in a side plank.

00:15:51

There’s research showing what a normal hold time for a side plank would be that you could then compare to. From an athletic standpoint though the best thing to do actually would be to have pre-injury data on all athletes. So we know exactly how long you can hold that side-plank before you got injured. Then we could test you as you’re going through rehabilitation to see if you are back to where you were at before. Maybe even we want you to get even better than that in the side plank or whatever the test is.

Kathryn: 00:16:22

Could I ask you how you define an injury?

Travis Pollen: Yeah, that’s a super fantastic question because that is like one of the biggest challenges from a research standpoint. It’s hard to compare between studies because a lot of studies define injury differently. So there’s a push lately to just try to get more consistency in the way that injury is defined. I can just give a few examples of how an injury is often defined.

00:16:53

So sometimes it is that the injury in an athletic setting it had to result in time loss. The athlete wasn’t able to train for at least a day or they had to miss a competition. That’s one injury definition. You could then grade that based on how much time the person missed. So if it was one day that’s like a relatively minor injury, if it was 10 days or three weeks we would call that more severe injury. Then you could also define injury based on whether the athlete sought medical attention.

If that athlete went to the athletic trainer’s office or they had a visit with a sports medicine doctor then the injury was severe enough in their eyes to seek medical attention. So those are the two most common definitions and they’re both valid. But the problem with that is if you look at two studies and two studies find different things then you try to compare them. It’s not exactly apples to apples because they were defining injury in a different way.

00:17:56

So it just depends on what your research question is and what the injury patterns look like in the population that you’re looking at and what the norms are for that population. The other side of the coin is who’s reporting those injuries? Are you querying the medical records that the doctor or the athletic trainer took? Or are you directly asking the athletes themselves?

What we find is that the athletes themselves, especially in the case of overuse injuries, tend to report more injuries. If you send them a weekly email and ask them whether they’ve had an injury in the last week. Rather then if you consult the athletic trainer. Sometimes the athletes just aren’t going to the athletic trainer for whatever reason. So that’s another side of the story.

Kathryn: 00:18:45

OK. I think that’s important. Yeah. That’s interesting. I guess I was expecting you to say something like If you have something that hurts then that’s an injury or something like that.

Travis Pollen: So that’s the tricky part, especially with swimming. There have been studies that have shown 9 out of 10 swimmers experience shoulder pain at some point in their career or in their season. If you just base it on the fact they had shoulder pain well then when you’re doing a study you need to separate the people who had pain in the people who didn’t. If almost everybody has pain, that makes it really difficult to tease anything out statistically.

00:19:24

So for that reason, I used a different definition that has never been used before. Which was just if they had pain that interfered with their ability to train for 50% of one practice. Which is well-defined. But how do you define what 50% is? That’s kind of like a judgment call. There were instances where the athlete said that it didn’t affect them that much and the coach thought it did. And so then I had to get to the bottom of that a little bit more. But that’s tricky at first.

When I was writing about it in my dissertation I was calling it an interfering injury. One of my advisers who is overseeing the work said you’re really asking them about pain. You should change that word to pain and not injury. So there’s a there is a subtle difference between those two things.

Kathryn: 00:20:08

Yeah and I guess what that does is also just normalize pain a little bit especially in athletes.

Travis Pollen: Yeah. Which can be good and bad. That’s another thing in the swimming literature. It shows that the pain because it’s so prevalent, a lot of swimmers just consider it a normal part of the training process due to the high volume.

What that does is make them tend to swim through the pain and not sit out because of it. In some situations that can be OK. If somebody is dealing with chronic pain and the exercise aggravates their pain but we know exercise is good for them. If they can stay below a certain threshold of pain, that could have positive implications for their recovery and for their pain levels overall.

00:20:55

But when you’re talking about a swimmer who’s having severe pain and they’re continuing to exacerbate it because they don’t want to miss out on training. They don’t want the coach to know that they’re injured. They don’t want to disappoint their teammates or they don’t want to look weak in the eyes of their teammates.

So many different reasons why they could be continuing to do that. But that can contribute to more long term problems where maybe if you caught it in the first instance and you let it in the bud then it might not be a problem.

Kathryn: 00:21:22

OK. So back to the risk factors. The major risk factor was previous injury. Was there anything else you want to mention?

Travis Pollen: Yes. So the training load was the other really big focus of my work. It is a really hot topic right now in the global sports injury literature. I in particular looked at this ratio called the acute to chronic workload ratio.

Which is a ratio of the amount of training that the athlete had been doing in the most recent week compared to the most recent months of training. So let’s say for the last month you’ve been doing three sessions a week on average and this week you got really gung ho and you decided to do six classes.

00:22:11

If you take the 6 compared to the 3x/week for the last month before that. Six versus 3, it would be double. So your future chronic workload ratio would be 6 divided by 3 equals 2. And there is some research that shows that anything over a ratio of 1.5 increases an athlete’s risk of injury.

It came out in 2016 where they sort of talked about that 1.5 being the danger zone. That’s what they described that as. And over the last maybe two years there’s been a lot of argument back and forth about whether the way that that ratio was derived is mathematically rigorous and what it actually means. We need different types of study designs to sort of validate that further.

00:23:06

There’s a lot of arguing going on about that particular value. But the idea of that I think is pretty well agreed on. Just the premise not to do too much too soon and maybe we don’t even need a mathematical value to associate with that. Maybe we can just understand it conceptually.

Also when you do get down to research and you want to quantify these things then you do need a way to do it. And so that is the way that it’s often being done right now even though it is problematic.

I can say that from my research I did find that athletes were more likely to sustain an injury during weeks in which they’re future chronic workload ratio was high. Like over that 1.5 value. But I also just looked at the raw workload. The number of yards that they were swimming during that week, without comparing it or dividing it by the previous month.

00:24:05

I’ve also found that if you just look at the number of yards that they swam that week, there was a similar relationship. Where if they did a lot of training that week they were more likely to be injured, than weeks in which they did less training. So that is kind of contradictory to that model on which the acute to chronic workload ratio is based. Because the thinking is that as long as you’re accustomed to doing a lot of training over the last month then if you encounter a high workload in the current week, you are probably going to be OK because you’re used to it.

Versus if you have a low chronic workload for the last month and now suddenly you do a higher workload in that week then you’re more at risk. That’s not what I found. I didn’t find that athletes who were better prepared from the previous month were more at risk than just looking at the current week of training.

Kathryn: 00:24:59

Do you think that’s because they got like really well recovered?

Travis Pollen: So that’s definitely part of it and that’s the confusing thing if you just look at the external workload. Which is just the general amount of training that they’re doing. Which says nothing about how the athlete is responding to that training or what their state of recovery is.

00:25:20

I haven’t seen a lot of research that has combined these two things. But I was just talking to a friend who is a strength coach for a college football team. The way that he does it is he not only looks at the training volume but in particular, they also look at the number of yards that an athlete has run above a certain mile per hour.
So that’s really high-intensity training and there’s a certain volume of training that they want to stay below in a given practice or over the course of the week.

But then they’ll also marry that with how the athlete is responding based on fairly frequent vertical jump testing. If you know what an athlete’s average or normal vertical jump height is and the variability of that, then you can see if an athlete comes in today and they’re way below that average, that means that they’re likely under recovered.

00:26:17

We can then look at what they just did well they had a practice or a series of practices where they ran a ton of that high-velocity, high miles per hour. Let’s say it was wide receivers and there were running routes. So if you have both of those things then now we want to seriously consider with this athlete whether they need to take a step back from the training for a few days and try to get them a little bit more recovered.

That’s how it would apply in a high-performance football setting. But it could apply equally to a yoga context where you’re looking at how much of the movement practice you’ve been doing. You can even just ask yourself well how am I feeling today? There are so many things that can go into that. How has your sleep been? How has your nutrition been? How’s your hydration? How is your stress?

00:27:10

If you wanted to, you could quantify those things by taking a daily wellness questionnaire and rate each of those things on a one through five scale. Then look at that over time. Or you could just simply ask yourself or your students “how are you feeling today? If we’re talking about a certain pose like handstands maybe, where we know that going upside down, if you fell over from that you could hurt yourself.

Whether a student decides to do their handstand on that day or just stick to some sort of modified handstand progression, the teacher in a one on one setting could ask the student any of those questions are just simply how are you feeling that day.

And I think that already happens to a large extent. Do you want to do a handstand today? Yes or no. Why would you or would you not feel comfortable doing it today based on all those many factors.

Kathryn: 00:28:02

What you said about the idea of having like the vertical jump test to check in on how people are doing and then kind of gauge from there. I think that is really interesting. Like a cool way of checking in with someone.

Travis Pollen: So that’s one that’s commonly used. Another one that’s commonly used is handgrip strength. I have a handgrip dynamometer that I bought on Amazon for $30 dollars. I’ll use that sometimes. Just a quick squeeze or two on each hand. See how that compares to what I’m usually able to grip and I’ll do that at the beginning of a workout just to see what’s my neurological state today. Am I under ready, I guess you could say, or is my grip really strong today and I’m going to push my training.

00:28:46

You could readily do that in a yoga context. What’s my grip today? Okay, I’m going to do a more rigorous practice or I’m going to do something more restorative because I’m not feeling ready to go today. Or you could take it and realize today you just need a little bit more of a warm-up in the strength training session or in the yoga session before I get to the heavier lifts or the more intense bout. Maybe you just need to ramp yourself up a little bit.

The last one that comes to mind immediately is resting heart rate I’ve actually found that if my resting heart rate is higher than usual I may be a few days away from getting a cold. And this is purely anecdotal I don’t think there’s research on this. Maybe there is?

I know that I’m recovered when my resting heart rate comes back to normal. This is just a very rudimentary way of looking at it because there’s a more advanced metric called heart rate variability that looks at between-beat variability and that can also be a way to gauge how recovered the athlete is

Kathryn: 00:29:57

So one thing that I think is interesting, we’ve been talking about injury risk and so we’ve looked at what an injury is, previous injuries the potential of too much too soon, recovery, nutrition, all of those different things. But in the postural yoga setting, there’s a lot of talk right now about injuries. I think the first thing that comes to people’s mind when you ask them about injury risk is alignment and I don’t hear any of that from you right now?

Travis Pollen: It’s funny that this is coming after all those things because at the beginning of my doctoral journey, that was the primary thing that I was also interested in. It was actually the reason why I chose to study at Drexel with my mentor. Her most recent research with her previous Ph.D. student developed this really comprehensive movement assessment.