This summer the Steele Lab had the pleasure of hosting three undergraduate researchers – Robin Yan from University of Washington, Ava Lakmazaheri from Olin College of Engineering, and Katherine Chamblin from University of Washington.
After a competitive selection process, students are offered a 10-week internship here at the University to work directly with a research lab on campus. One of the program’s final deliverables is a presentation of their work, both in podium and poster format, to members of the local and scientific community. Congratulations to Robin, Ava, and Katherine for their successful time here in the lab, and for giving polished presentations.
REU Students with their lab mentors
Robin examined biomechanical analyses of typically developing individuals during emulation of cerebral palsy gait and Ava worked on optimizing musculoskeletal models for children with cerebral palsy.
Katherine discussing her work with an interested student
Katherine investigated social communication patterns of children with cerebral palsy and their families after integrating an early-powered mobility device
Five members of our lab – Kat, Michael, Alyssa, Megan, & Nicole – attended ISB 2019 in Calgary, Canada. The International Society of Biomechanics promotes and supports international contacts amongst scientists, the dissemination of knowledge, and the activities of national organizations in the field of biomechanics.
Our work at the conference included:
Kat Steele: ISB presentation on in-clinic EMG monitoring for muscle activity and movement in acute care in the initial days after stroke. Michael Rosenberg: ISB poster showcasing how individuals’ kinematics and muscle activity change in response to ankle exoskeleton stiffness during acceleration from standing. ISB presentation on open-loop modeling of response to ankle exoskeleton torque during walking. Alyssa Spomer: ISB poster highlighting how motor control is impacted when typically developing individuals emulate cerebral palsy gait patterns. ISB poster on understanding how individuals can alter motor control expression using visual biofeedback. Megan Auger: ISB presentation on how muscle coordination strategies in typically developing children and children with cerebral palsy are not accurately captured using standard musculoskeletal modeling optimization algorithms in computer simulation. Nicole Zaino: ISB presentation on spasticity reduction via rhizotomy in children with cerebral palsy and how there was no significant difference in the change in energy consumption when compared to a control group of children with cerebral palsy who had no rhizotomy.
TGCS 2019
Additionally, two members of our lab – Michael & Megan – attended TGCS 2019 in Canmore, Canada prior to ISB 2019. The Technical Group on Computer Simulation (TGCS) is a scientific and technical meeting for investigators and students in all areas of computer simulation in biomechanics. This group was a highly-focused subset of the ISB community, primarily focusing on forward simulation of unimpaired and pathological gait patterns, but also touching on multi-scale simulation, diving, cycling, and wheelchair use.
Michael Rosenberg: TGCS presentation on Dynamic Mode Decomposition for modeling response to ankle exoskeletons during gait.
Five members of our lab – Brandon, Christina, Nick, Michael, & Kat – attended RehabWeek 2019 in Toronto, Canada. This is a unique mega-conference where multiple conferences (ICORR, ACRM, ISPO, RESNA, etc) are hosted at the same time in the same location. Everyone attended common keynotes, poster sessions, and meals. In the morning and afternoon, each conference had their own scientific sessions.
While it was a bit overwhelming to figure out which sessions to attend, it was a great way to get a more diverse audience to provide feedback on your work. For future conferences, I would recommend that students just pick one conference (e.g., ICORR or RESNA) to attend and not bounce between sessions. This lets you more fully engage with a community, have long discussions, and identify common threads across presentations.
Our work at the conference included:
Michael Rosenberg: ISPO presented on how muscle coordination differs when you start to walk compared to steady-state walking. Synergies differ during the first step, but quickly converge to steady-state patterns and there was minimal effect of different AFO stiffnesses.
Christina Papazian: INERS poster demonstrating correlations between FIM scores and muscle activity in acute stroke care.
Brandon Nguyen: ISPO poster on the accuracy and repeatability of using a smartphone to monitor gait for AFO tuning – ISPO Best Student Poster Award
Nick Baicoianu: Developer’s Showcase for HuskySTEPS
Kat Steele: ISPO poster on synergy-based control of predictive simulations of walking.
I also served on the IEEE Women in Engineering panel at lunch on Thursday, which focused on new frontiers in technology that could increase accessibility and inclusion. A lot of the discussion focused on the potential of machine learning, wearable technology, and autonomous vehicles.
You can view our notes and take-aways from the conference in these slides.
We also got to visit with Naser Mehrabi, a former post-doc in the lab, who now works for General Motors. We took the train just north of downtown to visit with him, his wife, and their 9-week-old son. Not only did we get to enjoy some delicious Iranian food, but we also got to get lots of simulation questions answered.
The next RehabWeek will be 2021 in Rotterdam, Netherlands.
Walking takes energy – but for kids with cerebral palsy, walking can be exhausting. The average child with cerebral palsy consumes two times the amount of energy during walking compared to typically-developing peers – that is the equivalent of jogging or climbing stairs!
The reasons for why walking takes so much energy for children with cerebral palsy remains largely unknown. The extra muscle activity caused by spasticity has often been theorized as a large contributing factor. If this was true, we would expect that treatments that reduce spasticity, like selective dorsal rhizotomy, could dramatically reduce energy during walking.
Led by Nicole Zaino, a new PhD student in the lab, and our collaborator Mike Schwartz at Gillette Children’s Specialty we have been investigating this question. By analyzing energy consumption for children with cerebral palsy who underwent rhizotomy and matched peers with cerebral palsy, we were determined that reducing spasticity does not lead to dramatic decreases in energy consumption.
This research has been nominated as a finalist for two awards at the International Society of Biomechanics Conference. This work was selected as one of 5 finalist for the Clinical Biomechanics Award. Nicole will also present as one of the finalists for the David Winter Young Investigator Award. The final awards will be announced at the conference in Calgary the first week of August. Good luck Nicole!
You can learn more about the study and read the preprint on BioRxiv:
Musculoskeletal models of gait with lower dimensional control spaces showed that an individual with reduced number of synergies could not produce an unimpaired gait
Background: Recent studies have postulated that the human motor control system recruits groups of muscles through low-dimensional motor commands, or muscle synergies. This scheme simplifies the neural control problem associated with the high-dimensional structure of the neuromuscular system. Several lines of evidence have suggested that neurological injuries, such as stroke or cerebral palsy, may reduce the dimensions that are available to the motor control system, and these altered dimensions or synergies are thought to contribute to impaired walking patterns. However, no study has investigated whether impaired low-dimensional control spaces necessarily lead to impaired walking patterns.
Methods: In this study, using a two-dimensional model of walking, we developed a synergy-based control framework that can simulate the dynamics of walking.
Results: The simulation analysis showed that a synergy-based control scheme can produce well-coordinated movements of walking matching unimpaired gait. However, when the dimensions available to the controller were reduced, the simplified emergent pattern deviated from unimpaired gait. A system with two synergies, similar to those seen after neurological injury, could not produce an unimpaired walking pattern.
Conclusions: These findings provide further evidence that altered muscle synergies can contribute to impaired gait patterns and may need to be directly addressed to improve gait after neurological injury.
