Portable Powered Orthotic Devices and Movement Simulators

Hsiao-WeckslerElizabeth T. Hsiao-Wecksler

Department of Mechanical Science and Engineering
University of Illinois at Urbana-Champaign

We are developing and understanding capabilities for portable powered orthotic devices (single-joint robotic exoskeletons). My group is interested in addressing issues of bulk, weight, control, and runtime, which are significant barriers for these devices. We have developed the first fully untethered portable powered ankle-foot-orthosis (PPAFO) which uses pneumatics to provide power-assisted ankle motion control. PPAFO efficacy is being assessed in persons with Parkinson’s disease, multiple sclerosis, and post-stroke conditions. Recent work addresses two new projects. One is exploiting the compact and lightweight nature of pneumatic soft robotics to develop powered upper extremity orthoses. We are focusing on developing arm orthoses for use during gait with pediatric Lofstrand crutch users. The other new project is developing simulators that can mimic muscle impairments seen with brain lesions (spasticity, clonus, cogwheel rigidity, and lead pipe rigidity). This project will develop upper extremity simulators so physical therapy and medical students can experience those behaviors; it is a collaboration with faculty in Physical Therapy and Mechanical Engineering at Bradley University in Peoria.


  1. Shorter, K.A., G.F. Kogler, E. Loth, W.K. Durfee, and E.T. Hsiao-Wecksler, “A Portable Powered Ankle-Foot-Orthosis for rehabilitation,” Journal of Rehabilitation Research & Development, 48(4): 459-472, 2011. http://www.rehab.research.va.gov/jour/11/484/pdf/shorter484.pdf
  1. Boes, M.K., M. Islam, Y. D. Li, and E.T. Hsiao-Wecksler. “Fuel Efficiency of a Portable Powered Ankle-Foot Orthosis,” IEEE 13th International Conference on Rehabilitation Robotics (ICORR 2013), Seattle, WA, June 24-26, 2013. http://dx.doi.org/10.1109/ICORR.2013.6650445
  1. Petrucci, M.N., C.D. MacKinnon, and E.T. Hsiao-Wecksler. “Modulation of Anticipatory Postural Adjustments of Gait Using a Portable Powered Ankle-Foot Orthosis,” IEEE 13th International Conference on Rehabilitation Robotics (ICORR 2013), Seattle, WA, June 24-26, 2013. http://dx.doi.org/10.1109/ICORR.2013.6650450



Liz Hsiao-Wecksler is an Associate Professor and Willett Faculty Scholar in the Department of Mechanical Science & Engineering at the University of Illinois at Urbana-Champaign. She is an affiliate in the Departments of Bioengineering, Industrial & Enterprise Systems Engineering, and Neuroscience; the Beckman Institute; the Center on Health, Aging and Disability; and the multi-institutional NSF Engineering Research Center for Compact and Efficient Fluid Power. Her research addresses locomotion biomechanics and assistive device design & development, with a focus on investigating and improving movement control and function in able-bodied and disabled populations. Her research program has been supported by grants from agencies such as the NSF, NIH, and Dept. of Homeland Security; has published over 50 peer-reviewed journal papers and extended conference proceeding papers, and 100 conference abstracts/presentations; is currently prosecuting 3 U.S. patents; graduated 8 Ph.D., 21 M.S., and over 80 undergraduate students; and created 1 small business.