Author: Dr. Steele

AccessEngineering featured on UW College of Engineering’s website

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Thanks to AccessEngineering and other DO-IT programs, I don’t feel like I’m pursuing my education alone, or that I have to figure out how to overcome obstacles that others don’t have to by myself.

AccessEngineering, an interdisciplinary universal design program co-led by Dr. Kat Steele at the University of Washington, was featured on the College of Engineering’s news webpage.

Since it’s launch in 2014, AccessEngineering has sought to champion the development of a diverse, well-prepared workforce of engineering graduates and university faculty. One of the key ways that this program seeks to promote this agenda is by increasing general participation of individuals with disabilities in engineering. AccessEngineering also aims to promote their core goals by improving engineering education. The primary means by which this group seeks to enrich the curriculum is by integrating disability-related and universal design content into engineering courses.

Dr. Kat Steele coordinates AccessEngineering at the UW with Dr. Maya Cakmak, an assistant professor in the Paul G. Allen School of Computer Science & Engineering, and Dr. Sheryl Burgstahler, director of UW Access Technology and the DO-IT Center.

To read about AccessEngineering program as posted on College of Engineering website, follow this LINK, or visit the program’s website.

Lab members attend the Society of Women Engineers 2017 Conference

Dr. Steele HuskyADAPT, News, Presentation, Projects, Publications

Momona Yamagami and Karley Benoff attended the Society of Women Engineers (SWE) 2017 conference in Austin, TX. Momona presented on her work with assessing a flexible electrode for long-term electromyography measurements and placed among the top 10 finalists in the graduate research poster competition for SWE. Congratulations Momona!

Momona Yamagami presents her research during a poster session

 

Karley said that SWE 17 was an incredible experience filled with opportunities for professional growth and networking. Here are some of her impressions:

“My favorite guest talk was titled “TECHing While Women and with Disability” where five panelists shared their experiences navigating the engineering world with a disability and/or as an advocate for those with disabilities. Dr. Richard Ladner of the University or Washington CSE department (pictured with Karley below) was one of the panelists. His research on accessible technology, especially technology for the blind, deaf, deaf-blind, and hard-of-hearing, was truly inspiring. The panelists’ presentations provided a unique perspective for approaching user-centered design. I hope to use the lessons learned from the panelists, as well as from all of the SWE 17 attendees I met, to better inform the development of my orthosis project this year. By targeting accessibility and user-centered design, I aspire to develop a universal elbow-driven orthosis that will improve function for users with a wide variety of abilities.

The panelist idea is something HuskyADAPT wants to organize for its club members. Since I am an officer in the club, we are currently trying to plan such an event to better inform design teams and members alike about peoples’ experiences living with disabilities. By understanding what each individual needs, we can better design devices and technology to address what the user wants.”

Karley Benoff with one of the panelists Dr. Richard Ladner of the University or Washington CSE department

 

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

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Journal article in Journal of Biomechanics:

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

Abstract

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.

 

 

A Rozumalski, KM Steele, MH Schwartz (2017) “Muscle synergies are similar when typically developing children walk on a treadmill at different speeds and slopes.” Journal of Biomechanics

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There were minimal changes in EMG signals with walking speed and slope.

Journal article in Journal of Biomechanics:

In collaboration with Gillette Children’s Specialty Healthcare, we evaluated whether muscle synergies change when unimpaired individuals walk at different speeds and slopes.

There were minimal changes in EMG signals with walking speed and slope.Background: The aim of this study was to determine whether changes in synergies relate to changes in gait while walking on a treadmill at multiple speeds and slopes. The hypothesis was that significant changes in movement pattern would not be accompanied by significant changes in synergies, suggesting that synergies are not dependent on the mechanical constraints but are instead neurological in origin.

Methods: Sixteen typically developing children walked on a treadmill for nine combinations (stages) of different speeds and slopes while simultaneously collecting kinematics, kinetics, and surface electromyography (EMG) data. The kinematics for each stride were summarized using a modified version of the Gait Deviation Index that only includes the sagittal plane. The kinetics for each stride were summarized using a modified version of the Gait Deviation Index – Kinetic which includes sagittal plane moments and powers. Within each synergy group, the correlations of the synergies were calculated between the treadmill stages.

Results: While kinematics and kinetics were significantly altered at the highest slope compared to level ground when walking on a treadmill, synergies were similar across stages.

Conclusions: The high correlations between synergies across stages indicate that neuromuscular control strategies do not change as children walk at different speeds and slopes on a treadmill. However, the multiple significant differences in kinematics and kinetics between stages indicate real differences in movement pattern. This supports the theory that synergies are neurological in origin and not simply a response to the biomechanical task constraints.

KM Steele, BR Shuman, MH Schwartz (2017) “Crouch severity is a poor predictor of elevated oxygen consumption in cerebral palsy.” Journal of Biomechanics

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Scatter plot illustrating that there is not a significant correlation between minimum knee flexion angle during stance and oxygen consumption.

Journal article in Journal of Biomechanics:

Does energy consumption during walking increase with crouch severity among children with cerebral palsy?

Scatter plot illustrating that there is not a significant correlation between minimum knee flexion angle during stance and oxygen consumption.Abstract: Children with cerebral palsy (CP) expend more energy to walk compared to typically-developing peers. One of the most prevalent gait patterns among children with CP, crouch gait, is often singled out as especially exhausting. The dynamics of crouch gait increase external flexion moments and the demand on extensor muscles. This elevated demand is thought to dramatically increase energy expenditure. However, the impact of crouch severity on energy expenditure has not been investigated among children with CP. We evaluated oxygen consumption and gait kinematics for 573 children with bilateral CP. The average net nondimensional oxygen consumption during gait of the children with CP (0.18 ± 0.06) was 2.9 times that of speed-matched typically-developing peers. Crouch severity was only modestly related to oxygen consumption, with measures of knee flexion angle during gait explaining only 5–20% of the variability in oxygen consumption. While knee moment and muscle activity were moderately to strongly correlated with crouch severity (r2 = 0.13–0.73), these variables were only weakly correlated with oxygen consumption (r2 = 0.02–0.04). Thus, although the dynamics of crouch gait increased muscle demand, these effects did not directly result in elevated energy expenditure. In clinical gait analysis, assumptions about an individual’s energy expenditure should not be based upon kinematics or kinetics alone. Identifying patient-specific factors that contribute to increased energy expenditure may provide new pathways to improve gait for children with CP.