NBC Learn: Exoskeletons and Engineering

NBC Learn logo for the Discovering YOU series - engineer your world. Supported by NSF, Chevron, and ASEE.

We partnered with NBC Learn to share some of our work on exoskeletons to help encourage students to consider a career in engineering. What can be more exciting than musculoskeletal modeling, exoskeletons, horses, and stuffed animals?

Check out the video – a lesson plan will also be posted soon for classrooms to use.

Go team!

Jessica Zistatsis Successfully Defends Her Master’s Thesis

Jessica Zistatsis has successfully defended her Master’s Thesis here at the University of Washington, in Dr. Steele’s Ability & Innovation Lab.

To complete her Master’s in full, Jessica will be submitting and disseminating her thesis, A Passive Pediatric Exoskeleton to Improve the Walking Ability of Children with Neuromuscular Disorders.

To begin watching Jessica’s defense, you may view Part 1 on YouTube HERE, or directly below:

A silly congratulations graphic made by the lab depicting the fictional Godzilla stomping through downtown Seattle, while wearing PlayGait, the pediatric exoskeleton Jessica worked on for her masters. Test within the photo reads, "Congrats on destroying your defense, Jessica!"Our lab could not be more proud! To help celebrate her successful defense, the lab drafted a flyer depicting an empowered Godzilla wearing PlayGait, Jessica’s pediatric exoskeleton. Here’s hoping future children will use their newfound superpowers for good, unlike our friend in this picture!


AA Portnova, G Mukherjee, KM Peters, A Yamane, KM Steele (2018) “Design of a 3D-printed, open-source wrist-driven orthosis for individuals with spinal cord injury.” PLOSOne

Journal article in PLOSOne: In collaboration with the University of Washington Prosthetics and Orthotics Division, a user-centered design approach was used to improve the design and wearability of a passive, wrist-driven orthosis. To read the article in full, click HERE. To access the open-source print files, click HERE.

Orthotists in training assemble the 3D-printed parts of a new wrist-driven orthosis in the top image. The lower image showcases a user gripping a pen in his freshly donned orthosis.Background: Assistive technology, such as wrist-driven orthoses (WDOs), can be used by individuals with spinal cord injury to improve hand function. A lack of innovation and challenges in obtaining WDOs have limited their use. These orthoses can be heavy and uncomfortable for users and also time-consuming for orthotists to fabricate.

Purpose/Methods: The goal of this research was to design a WDO with user (N = 3) and orthotist (N = 6) feedback to improve the accessibility, customizability, and function of WDOs by harnessing advancements in 3D-printing.

Results: The 3D-printed WDO reduced hands-on assembly time to approximately 1.5 hours and the material costs to $15 compared to current fabrication methods. Varying improvements in users’ hand function were observed during functional tests, such as the Jebsen Taylor Hand Function Test. For example, one participant’s ability on the small object task improved by 29 seconds with the WDO, while another participant took 25 seconds longer to complete this task with the WDO. Two users had a significant increase in grasp strength with the WDO (13–122% increase), while the other participant was able to perform a pinching grasp for the first time.

The WDO designs are available open-source to increase accessibility and encourage future innovation.

H Choi, KM Peters, M MacConnell, K Ly, E Eckert, KM Steele (2017) “Impact of ankle foot orthosis stiffness on Achilles tendon and gastrocnemius function during unimpaired gait.” Journal of Biomechanics

Journal article in Journal of Biomechanics:

How does the stiffness of an AFO impact the muscultendon dynamics of the gastrocnemius?


Method combining ultrasound and musculoskeletal modeling to evaluate changes in muscle and tendon length.

Ankle foot orthoses (AFOs) are designed to improve gait for individuals with neuromuscular conditions and have also been used to reduce energy costs of walking for unimpaired individuals. AFOs influence joint motion and metabolic cost, but how they impact muscle function remains unclear. This study investigated the impact of different stiffness ankle foot orthoses (AFOs) on medial gastrocnemius muscle (MG) and Achilles tendon (AT) function during two different walking speeds. We performed gait analyses for eight unimpaired individuals. Each individual walked at slow and very slow speeds with a 3D printed AFO with no resistance (free hinge condition) and four levels of ankle dorsiflexion stiffness: 0.25 Nm / °, 1 Nm / °, 2 Nm / °, and 3.7 Nm / °. Motion capture, ultrasound, and musculoskeletal modeling were used to quantify MG and AT lengths with each AFO condition. Increasing AFO stiffness increased peak AFO dorsiflexion moment with decreased peak knee extension and peak ankle dorsiflexion angles. Overall musculotendon length and peak AT length decreased, while peak MG length increased with increasing AFO stiffness. Peak MG activity, length, and velocity significantly decreased with slower walking speed. This study provides experimental evidence of the impact of AFO stiffness and walking speed on joint kinematics and musculotendon function. These methods can provide insight to improve AFO designs and optimize musculotendon function for rehabilitation, performance, or other goals.



Jessica Zistatsis awarded CoMotion Innovation Fund grant

We are proud to announce that our very own Jessica Zistatsis has been awarded the CoMotion Innovation Fund grant. Jessica’s application process included market research, customer surveys, a lean canvas, and a 10 min pitch to a panel of investors. The CoMotion Innovation Fund will provide $40,000 to support research along with $10,000 for business development assistance through UW CoMotion.

jessicazThis award will support clinical trials with 10 kids with CP trying PlayGaitTM in Spring and Summer 2017 along with two quarters of Research Assistant support.

Jessica also just filed for a provisional patent.
Congratulations, Jessica!