Using Dynamic Simulations to Investigate Muscle Forces during the Sit to Stand Transfer and Stair Climbing

By: Elena Caruthers

Noon – 1 pm E100

Abstract: While activities of daily living such as rising from a chair or climbing stairs are performed with relative ease by healthy adults, they are considered to be some of the most challenging activities in the home, especially for the elderly and those with lower limb pathologies such as knee osteoarthritis. Current rehabilitation strategies used for these populations are not 100% effective as some patients do not have significant improvements in pain or the ability to rise from a chair or climb stairs. In order to potentially improve and inform targeted intervention programs, the role of individual muscles needs to be investigated further. I will describe the utility of experimental tools such motion capture, which has been used for movies like Avatar, and how they can be used in joint with dynamic simulations to study the behavior of individual muscles, including estimating individual muscle forces produced during a task. I will also discuss the work my collaborators and I did to investigate muscle forces generated when rising from a chair or during stair climbing in a young, healthy population and how these results can be used in the future to help inform current rehabilitation strategies for populations that experience difficulty completing those tasks.

Bio: Elena Caruthers received a B.S. degree in engineering (with a mechanical emphasis) and a B.A. in dance from Hope College in 2012. She is currently pursuing her doctoral degree at The Ohio State University in Mechanical Engineering, working for Dr. Robert Siston in the Neuromuscular Biomechanics Laboratory. While at Ohio State, she was awarded the National Science Foundation Predoctoral Fellowship in 2013 and was selected to be an instructor for mechanics of materials at Ohio State through the Future Faculty Program in the 2015-16 school year. Her research interests include lower limb muscle function during activities of daily living in healthy and pathological populations as well as engineering education.

Due to the engineering expo, we will have our next meeting one week from today!

Impulse and Foot Placement Control in Human Running

By: Nidhi Seethapathi

Noon – 12:30pm E525

Abstract: Constant-speed human running is not exactly periodic. For instance, the body states of the person during the flight phase fluctuate about a mean value. Despite these noise-like deviations, people are able to run without falling down. Here, we examine how these natural state fluctuations are controlled using ground reaction forces and foot placement during running. We use natural step-to-step variability to infer such control. We find that most of the deviation in the sideways and fore-aft speed at mid-flight is nullified by a corrective impulse in the following foot-strike. In achieving this, people modulate the negative part of the ground reaction force more than the positive part. Further, we find that foot placement is used a control more in the sideways direction than in the fore-aft direction. The methods and results in this work can be used to better understand how such a controller for running differs in professional runners who are more practiced.

Join us on Wednesday for the first meeting of Student Lecture Series! Enjoy pizza and soda while we discuss recent changes, followed by a presentation by Mike Adams – Applications and Materials for Solid State Energy Conversion.