Dr. Andrew Hagen joins the "Off the Field" series to discuss how his lab uses unique functional MRI techniques to study how the brain controls physical movement. The conversation explores how understanding brain activity during exercise can lead to more effective rehabilitation strategies and reduced injury risks for athletes.
Media/Articles Referenced:
Check out our video of the MRI machine at SPARC. It features a tennis ball filled with paper clips to show you the power of the magnet!
Hagen, A. C., Tracy, B. L., & Stephens, J. A. (2024). Altered neural recruitment during single and dual tasks in athletes with repeat concussion. Frontiers in human neuroscience, 18, 1515514.
Melissa: Welcome to Behind the Breakthroughs. I'm Melissa Deuber from the Woodruff Health Sciences Center Library. In each edition, we take a closer look at the research shaping health, healing, and human performance at Emory. Today's episode is part of the Off the Field series, where we explore how science moves from the lab to everyday life. I'm joined by Dr. Andrew Hagen to talk about their work, the questions that drive it, and what it could make possible.
Let's get started. So, tell us a little bit about yourself and what got you into this field of research?
Dr. Hagen: Yeah, good question. I've always been interested in how the brain controls how we move. So, when I was an undergraduate I studied biomechanics, how the body moves and the different mechanics of how that occurs, and then during my PhD I explored neuroscience. Putting them together is really where my passion is.
Melissa: Great. So, if you had to explain kind of what you do on a daily basis to a friend or family member that maybe doesn't work in science or health, what would you say?
Dr. Hagen: Yeah, so we're really interested in combining brain imaging with biomechanics to understand how the brain controls movement and brain-behavior relationships. So, essentially what this looks like day-to-day is I work with an MRI machine that's essentially just a big electromagnet and it allows us to move protons around to take very clear pictures of things in the body.
Specifically, I work with functional MRI, and this allows us to measure brain activity changes, including blood oxygenation. Essentially what happens is neurons in the brain that are consuming more oxygen are generally more active, so we can understand this response. What's unique about our studies is that with our functional MRI signals, we can look at these while people are actually moving in the scanner. So we can quantify their movement quality at the same time as measuring brain activity.
Melissa: I've never heard of someone moving in an MRI, so that's definitely new. What do these techniques let you do or what questions do they let you answer?
Dr. Hagen: Yeah, absolutely. And it is very unique that we can do this, which is super nice. We're only one of a handful of places in the whole world to have this capability to measure movement quality with motion capture while somebody's in an MRI scanner. So what we can do is, historically, people haven't been able to move in the MRI because you have to remain motionless with your head so that we can get a good signal, otherwise noise occurs. So, we have some different techniques that we can use and different devices that allow us to be able to move in the MRI.
And we want to be able to move because that's what things actually look like compared to sports, for instance. A lot of previous MRI research has focused on, you know, imagining walking for instance, or imagining other movements to see how the brain responds, but you and me both know that's not the same as actually doing that. So we want to make this as natural and realistic as we can to understand how the brain's really controlling movement.
So, for instance, what we can do is we have special devices that are compatible with the MRI machine that don't interrupt the magnets, that allow us to do hip, knee, and ankle flexion and extension. So we have like a leg press device that has foot pedals that are on tracks, and then has resistance bands on them so people can move one leg or both legs back and forth. We also have a similar device that's a leg press device with pneumatic pistons on it as well.
So we can very specifically control the resistance that they're getting and the timing of the resistance with air compressors, too. So together, what these devices allow us to do is we can, one, make them move that's more natural, measure the quality of their movement or specifically the mechanics of their movement, and get their brain activity signals all at the same time.
Melissa: That sounds like really interesting stuff. So, what's one thing you wish the general public understood better about how this type of research actually helps people?
Dr. Hagen: Yeah, that's a great question. One, just movement in general makes up so much of our life experience. Moving around in our environment, eating, making facial expressions... right now our mouths moving as we speak, all these are very precise control of the brain to our muscles. So understanding how we move is very important to a lot of things, but specifically in sports and injury, understanding how the brain controls how we move can help us lead to better treatments and better rehab as well.
So for instance, we know now because of research that team members here have done, that people who tear their ACL, for instance (that happens very commonly in sports) actually rely more on the visual system to control their movement compared to their more automatic motor system compared to people that don't have ACL injury. So now when people are trying to play sports again, their demands are going to be greater on the visual system because you need to know where people are, your teammates are, where the ball is, for instance. So we want to be able to rehab that and have that be meaningful to them.
So we can use treatments like neuromuscular training or neurocognitive training to train the brain to rely less on the visual system when they are moving, and this can help us reduce injury risk for the future and get us back to better performance as well.
Melissa: Right. So, is any of this research something that could eventually show up in someone's real life?
Dr. Hagen: Yeah, for sure. For knee injury, for example, some of this stuff already is showing up in physical therapy programs and return to sport programs. So as I mentioned, the neuromuscular and the neurocognitive training is starting to get a lot of evidence now that it's beneficial, and that's based on research that, for instance, my team has done to understand how the brain is controlling movements.
We also want to eventually create more precise rehabilitation strategies. If we know specific brain regions that are involved in this aberrant control of movement, we can have better ideas on how we can rehab those specific brain regions. And even for things like knee pain, if we have a better understanding of what regions of the brain are active during pain or maybe are controlling more painful movements, then we can come up with more precise therapies, even drugs, to improve pain.
Melissa: That sounds like a great result. So, if there is a young athlete or someone recovering from a major injury that's listening to this episode, what's something that you hope that they take away from your work?
Dr. Hagen: Yeah, that's a great question. That's really what really matters in the end of everything. The brain is essential to your recovery, and don't neglect it during your rehab. If you have an injury, we know that the brain learning to control your knee again, for instance, takes much longer than the actual structural healing of your knee. So oftentimes people regain their strength but still have deficiencies of how the brain controls how they move, especially in demanding environments like your sport. There's a lot of things that are taking the attention from your brain away in that case.
So rehab that includes cognitive training, reaction time, and movements like that is really important to prevent more injuries from occurring and even getting you back to your peak performance.
Melissa: Awesome. Well, thank you so much for being here, and thank you guys for joining us for this episode of Behind the Breakthroughs Off the Field. I hope today's conversation offered a clearer look at the curiosity, care, and science behind the work happening at Emory.
If you enjoyed this episode, feel free to explore the rest of the series, where each researcher brings a new perspective on injury prevention and human performance. Thanks for listening and we'll see you next time.