Our lab had a great time sharing our research at the College of Engineering Discovery Days. Our booth was entitled, “The Ultimate Machine” because we think of the human body as a complex system with our brain as a controller/computer and our muscles as our motors. Elementary and middle school students used their neural pathway, from brain to muscle, to control a robot gripper by either relaxing or activating their muscle. 
Projects
MH Schwartz, A Rozumalski, KM Steele (2016) “Dynamic motor control is associated with treatment outcomes for children with cerebral palsy.” Developmental Medicine & Child Neurology
Journal article in Developmental Medicine & Child Neurology:
Kat Steele partnered with Michael Schwartz from Gillette Children’s Specialty Healthcare to investigate the impact of dynamic motor control on varying treatments in children with cerebral palsy.
Aim
To estimate the impact of dynamic motor control on treatment outcomes in children with cerebral palsy.
Method
We used multiple regression on a retrospective cohort of 473 ambulatory children with cerebral palsy who underwent conservative treatment, single-level orthopaedic surgery, single-event multi-level orthopaedic surgery, or selective dorsal rhizotomy. Outcomes included gait pattern, gait speed, energy cost of walking, and the Pediatric Outcomes Data Collection Instrument. Explanatory variables considered were pre-treatment levels of each outcome, treatment group, prior treatment, age, and dynamic motor control computed from surface electromyography using synergy analysis. Effect sizes were estimated from the adjusted response.
Results
Pre-treatment levels had effect sizes 2 to 13 times larger than the next largest variable. Individuals with milder pre-treatment involvement had smaller gains or actual declines. Dynamic motor control was significant in all domains except energy cost. The effect size of dynamic motor control was second only to pre-treatment level, and was substantially larger than the effect size of treatment group for outcomes where both were significant (gait pattern 2:1, gait speed 4:1). The effect of dynamic motor control was independent of treatment group.
Interpretation
Dynamic motor control is an important factor in treatment outcomes. Better dynamic motor control is associated with better outcomes, regardless of treatment. PDF
Sasha Portnova Presents Poster in DC
Sasha Portnova is presenting her research at the 20th Annual Posters on the Hill in Washington DC today, April 20th. Out of 300 received applications, Sasha was one of 60 posters chosen for the presentation. She is sharing her work on: 3D-Printed Wrist-Driven Orthosis for Individuals with Spinal Cord Injury. Congratulations and Go Biomechanics!
Sasha Presents at the Northwest Chapter of AAOP
After presenting her work at the national American Academy of Orthotists and Prosthetists (AAOP) in Orlando, FL, Sasha was invited to present her work locally at the Northwest chapter of AAOP here in Bellevue. Great job sharing about your research, Sasha!
BR Shuman, M Goudriaan, L Bar-On, MH Schwartz, K Desloovere, KM Steele (2016) “Repeatability of muscle synergies within and between days for typically developing children and children with cerebral palsy.” Gait & Posture.
Journal article in Gait and Posture:
Filtering parameters impact the results from muscle synergy analyses.
Abstract: Muscle synergies are typically calculated from electromyographic (EMG) signals using nonnegative matrix factorization. Synergies identify weighted groups of muscles that are commonly activated together during a task, such as walking. Synergy analysis has become an emerging tool to evaluate neuromuscular control; however, the repeatability of synergies between trials and days has not been evaluated. The goal of this study was to evaluate the repeatability of synergy complexity and structure in unimpaired individuals and individuals with cerebral palsy (CP). EMG data were collected from eight lower-limb muscles during gait for six typically developing (TD) children and five children with CP on two separate days, over three walking speeds. To evaluate synergy complexity, we calculated the total variance accounted for by one synergy (tVAF1). On a given day, the average range in tVAF1 between gait cycles was 18.2% for TD and 19.1% for CP. The average standard deviation in tVAF1 between gait cycles was 4.9% for TD and 5.0% for CP. Average tVAF1 calculated across gait cycles was not significantly different between days for TD or CP participants. Comparing synergy structure, the average (standard deviation) within day correlation coefficients of synergy weights for two or more synergies were 0.89 (0.15) for TD and 0.88 (0.15) for CP. Between days, the average correlation coefficient of synergy weights for two or more synergies was greater than 0.89 for TD and 0.74 for CP. These results demonstrate that synergy complexity and structure averaged over multiple gait cycles are repeatable between days in both TD and CP groups.