ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Corbin Rasmussen is an author on ‘ Curvilinear walking elevates fall risk and modulates slip and compensatory step attributes after unconstrained human slips’, published in JEB. Corbin conducted the research described in this article while a PhD student in Nathaniel H. Hunt's lab at the Department of Biomechanics, University of Nebraska at Omaha, USA. Corbin is now a Postdoctoral Research Associate in the lab of Sara A. Myers, at the Department of Biomechanics, University of Nebraska at Omaha, USA, investigating the mechanisms of human balance recovery across commonly encountered walking environments and tasks.

Corbin Rasmussen

How did you become interested in biology?

When trying to pick my undergraduate major, I was torn between two paths. I was a three-sport athlete throughout high school and became very interested in athletic performance and injury prevention as a result, which pointed me toward exercise science. On the other hand, I also loved working with my hands on anything mechanical and therefore thought mechanical engineering could be the right option. I distinctly remember discovering biomechanics as a field after searching Google for ‘how to combine sports science and mechanical engineering’ and was instantly hooked. Viewing humans or animals as these extremely complex yet elegant machines struck me as such an interesting perspective. It seemed like the perfect marriage of my two interests. While I did end up choosing exercise science as my undergraduate major, I sought out any opportunity I could to learn more about biomechanics.

Describe your scientific journey and your current research focus

My scientific journey started as a volunteer research assistant in the Nebraska Athletic Performance Lab with Drs Judith Burnfield and Gui Cesar, where I applied to a university-sponsored undergraduate research program with a project on predictors of leg injuries in American football players (it was Nebraska after all, why wouldn't I study football?). This experience was also my first brush with the tools of the biomechanics trade. I was convinced at the time that athletics was where I wanted to be, but a later stint as a research assistant at Madonna Rehabilitation Hospital under Drs Burnfield and Cesar exposed me to the clinical applications of biomechanics and completely changed my course. I was blown away by the rapid improvements in patients served by our studies and that inspired me to pursue a research career where I could have the same clinical impact. As a master's and PhD student in Dr Nate Hunt's lab at the University of Nebraska at Omaha, I studied human slip recovery during walking over curved paths and sloped surfaces. I became fascinated by the ways in which we so effectively maintain dynamic balance, and I left my graduate studies with far more questions and ideas than I started with. I hope to continue this line of research to address those questions in my future career. I am currently a postdoctoral research associate in Dr Sara Myers' lab developing new therapeutic technology for service members, patients with vascular diseases, and individuals with balance problems, which has allowed me to gain valuable experience with clinical populations and broaden my skills in the technology transfer space.

How would you explain the main findings of your paper to a member of the public?

We turn during walking constantly to navigate around the many obstacles, corners and doorways that we encounter every day. The physics behind turning can increase the odds that you experience a slip and, if you are unable to quickly regain your balance, a fall that could cause severe injury. We investigated how attributes of a curved-path slip, such as the ‘sharpness’ of the turn, which foot slips relative to the turning direction, and the timing of the slip during walking, influence the severity of the slip and the recovery responses used to regain balance. We also examined the role of slowing when turning by making all study participants walk at the same speed during all trials. We found that slips on ‘sharper’ turns beginning closer to step placement of the inside foot relative to the turn are the most destabilizing and most challenging to recover from. Based on our findings, one reason for slowing down when turning may be to reduce the likelihood of slipping in the first place. These results can be used to develop new fall prevention methods that account for a greater range of walking scenarios used in daily life.

The Wearable Apparatus for Slip Perturbations (WASP) assembled on a shod prosthetic foot for presentation.

The Wearable Apparatus for Slip Perturbations (WASP) assembled on a shod prosthetic foot for presentation.

What do you enjoy most about research, and why?

There is so much I enjoy about research that I can't choose just one aspect. To me, there are few things more exciting than trying to push the boundaries of our knowledge. It takes a ton of work to get to that point, but the payoff of learning something new and sharing it with the greater scientific community is well worth the effort. I also enjoy the variety of ‘hats’ needed to conduct research; my tasks on any given day may be more fitting of a writer, teacher, engineer, statistician or graphic designer than what many outside of the research world would associate with a scientist. There has never been a moment when my job felt repetitive or boring. Finally, my research career has allowed me to meet and collaborate with some of the most amazing people from around the globe. Learning about their backgrounds and cultures has been one of the more enriching experiences of my graduate and post-graduate time.

What is the most important piece of equipment for your research, what does it do and what question did it help you address?

The most important piece of equipment is one that we invented ourselves: the Wearable Apparatus for Slip Perturbations (WASP). This device is triggered wirelessly to deliver slips that mimic those you would experience over a patch of ice on the sidewalk: the mechanics of the slipping foot are determined solely by the forces placed on it and the characteristics of the environment. Because WASP is wearable, slips can be delivered in any setting and the timing and location are unpredictable to the wearer. These advantages allow us to expand human slip-and-fall prevention research beyond straight, level walking, which has historically been the focus of this work but does not fully represent how we navigate our daily environments. Specific to our paper in JEB, WASP helped us determine the influence of various curved walking attributes, such as path curvature, slipped foot relative to the curved path, walking speed, and slip onset timing within stance phase, on the fall risk and balance recovery demands posed by realistic slips on non-straight walking paths. We believe this can inform more effective fall prevention strategies in humans and our understanding of robust bipedal balance more broadly.

What's next for you?

In terms of my research, I think WASP will allow us to examine aspects of dynamic balance in the future that were not as accessible before, which could have broader implications for our understanding of comparative biped balance. In humans specifically, these aspects can be targeted clinically in perturbation-based balance training protocols in an effort to reduce fall risk. I am also working in my current postdoctoral role to expand my study of balance to lower-limb amputees through the Veterans Affairs Medical Center in Omaha. My career goal is to start a lab of my own where I can continue my research career and have the same impact on the next generation of biomechanists as my mentors have had on me.

Corbin Rasmussen's contact details: Department of Biomechanics, University of Nebraska at Omaha, 6160 University Drive South, Omaha, NE 68182, USA.

E-mail: [email protected]

Rasmussen
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C. M.
,
Mun
,
S.
,
Ouattas
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A.
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Walski
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A.
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Curtze
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C.
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Hunt
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N. H.
(
2024
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Curvilinear walking elevates fall risk and modulates slip and compensatory step attributes after unconstrained human slips
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J. Exp. Biol.
227
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jeb246700
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