Alena Grabowski, PhD, Biomechanics at CU Boulder talked about the hurdles for developing a better prosthesis
Interview conducted by Ivanhoe Broadcast News in August 2019.
It’s a lot of things we all take for granted, right? The things that you don’t even think about when you’re just walking or running.
GRABOWSKI: Totally.
What got you interested in that?
GRABOWSKI: The pivotal moment for me was working with a guy named Oscar Pistorius. He’s an athlete from South Africa that has amputations below both knees and was a very exceptional 400 meter sprinter who used running-specific prostheses which are made of carbon fiber. And they’re sort of like springs. They store and return energy. And the use of those prostheses allowed him to compete at the highest level at the Olympics.
How’d you guys connect?
GRABOWSKI: I was part of the research team that allowed him to be able to compete.
And that itself in any Olympic athlete or any elite athlete – that is kind of a controversy right now.
GRABOWSKI: Yeah. It remains a controversy. And, in fact, there’s another athlete that’s faster than Oscar who also has bilateral below the knee amputations named Blake Leeper. And it’ll be really fun to see the impact he makes. And so the question still remains, how do prostheses function? Are they better or worse than a biological limb? And we’re doing a lot of research to try to get at that question.
A lot of your research involves just building better prostheses for everyone, not just sprinters, but you’re starting at sprinters.
GRABOWSKI: We do a lot of research on walking as well. There are new powered prostheses. They have a battery, a motor, transmission, electronics within them that allow people with amputations to be able to walk more effectively, which is the basic way we get around. And we work with people that need a walking prosthesis all the way to the fastest sprinters in the world. And I’m really interested in how prostheses affect that whole population. We’ve even got some full studies on kids with amputations, looking at how prosthetic feet affect the way they move.
There hasn’t been a lot of change in the last decade.
GRABOWSKI: For running, no, there hasn’t been a lot of change. For walking, there’s been quite a bit of change. This development of a new powered prosthesis has really changed the market and changed what’s available for people with amputations.
What are the hurdles for developing a newer, better leg to run?
GRABOWSKI: Running’s a little bit trickier than walking because it’s so much faster. So if I were to try to design a running-specific prosthesis that would enhance running, it would be something that had a very lightweight motor, something that allowed very quick feedback, something that was actually connected to the person so the person could actually drive that prosthesis, not just react to it. And so there’s a lot of aspects that would have to be perfect to really make that prosthesis work the best.
So where’s your research right now?
GRABOWSKI: What we’re doing right here today is we’re looking at differences in blades that are used as running-specific prostheses. Right now, we’ve got a blade made by a company called Fillauer. And they’ve got a prosthesis that basically is solid, typical of what is typically used. And then they have another prosthesis they designed that splits the toe of the blade. And I think something like that is going to work better around curves where you really need to have movement in different planes, not just straight forward.
What are you checking out in here today? If you can explain what’s going on.
GRABOWSKI: We’re measuring how different athletes with amputations move – by putting little reflective dots on them. And then we’re also characterizing the force they exert on the ground – so how hard they hit the ground when they go around that curve. And that tells us a lot of information about the kind of technique they can use and then also how fast they can go around the curve.
Why is this so important?
GRABOWSKI: Well, if you can go faster, you’re going to perform better. And you’re going to compete better. And that would probably be a better prosthesis.
The whole idea is to get these young people and everybody just to be normal.
GRABOWSKI: Yeah, get them active, get them able to do anything they want to do.
Do you think that there’s an unfair advantage going in?
GRABOWSKI: Absolutely not. No. I don’t think prostheses at this point provide any sort of advantage to an athlete with an amputation. I think if anything, it’s a disadvantage.
Why?
GRABOWSKI: It’s a spring. It can only store and return energy. It doesn’t have a motor on it. Our biological ankles and feet basically have muscles attached so that we can generate power and go faster by using muscles and tendons in combination. And a prosthesis can’t do that. It also can’t change its stiffness. You just get one prosthesis, and you can’t modify it as you’re running. It’s also not connected directly to the person. The connection is a rigid socket that goes outside the residual limb, so there’s no way for the person to actually control how the prosthesis moves or reacts.
What’s the next step for a prosthetic?
GRABOWSKI: There are probably multiple steps for the next prosthesis. I would say, if we can start to incorporate some sort of a motor in the device, that would be groundbreaking. So that’s something to think about. We’ve done a lot of studies on existing prostheses and trying to optimize those – optimizing their stiffness, optimizing the height and then optimizing the model whether it’s J-shaped, like the prostheses you see today, or C-shaped, which is another type of model.
Where does this come from when you’ve started to now? And where’s it going to go? Like are you excited?
GRABOWSKI: I’m really excited. We’re at a place right now where athletes are very high caliber. And they’re working extremely hard to be able to compete at the highest levels. And I’m hoping that we can start to keep up with them with prostheses and design and trying to basically let them compete at that level with prostheses that are at least equivalent to a biological limb.
I would say they have a different ability. They don’t have a disability. And these people are able to use running-specific prostheses to be able to run. And I think that’s super important in life.
When you watch these two young people today, do they just amaze you?
GRABOWSKI: Definitely.
And you are a runner. Tell me a little bit about that.
GRABOWSKI: I’ve been running since I’ve been walking almost. My mom was a track coach. And so I remember at a young age being able to run with the high school girls and that was so fun. I’ve just really kept up with running my whole life. And now I’m lucky enough to be able to run in the mountains, on the trails.
Do you think it kind of drew you to this, because you know what that feeling is when you’re out there running your 50-mile run?
GRABOWSKI: Definitely. I think I have the opportunity to get up in the morning, grab my running shoes and go out for a run and not think about much of anything else. And I want that opportunity to be available for everyone. So if you have an amputation, I want a person to be able to just pick up their blade and head out the door and not have to think about it.
So what about these athletes? Who are they? And where’d you find them? And how’d you get them here?
GRABOWSKI: Yeah. I know Jessica from working with her on the Paralympic track and field team. I had an opportunity to go out to Chula Vista, which is the U.S. Olympic Training Center and work with a group of sprinters with amputations a couple of years ago. And we did some research with them. And Alex, I’ve never met before until today. So he was recruited by Fillauer, which is sponsoring the study. And that’s how I got to know him a little bit.
END OF INTERVIEW
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