KM Steele, ME Munger, KM Peters, BR Shuman, MH Schwartz (2019) “Repeatability of electromyography recordings and muscle synergies during gait among children with cerebral palsy.” Gait & Posture

Journal Article in Gait & Posture:

Repeatability of EMG is similar between typically developing children and children with cerebral palsy.

Background: Clinical gait analysis is commonly used in the evaluation and treatment of children with cerebral palsy (CP). While the repeatability of kinematic and kinetic measures of gait has previously been evaluated, the repeatability of electromyography (EMG) recordings or measures calculated from EMG data, such as muscle synergies, remains unclear for this population.

Research Question: Are EMG recordings and muscle synergies from clinical gait analysis repeatable between visits for children with CP?

Methods: We recruited 20 children with bilateral CP who had been referred for clinical gait analysis. The children completed two visits less than six weeks apart with EMG data collected bilaterally from five muscles (rectus femoris, medial hamstrings, vastus lateralis, anterior tibialis, and medial gastrocnemius). Variance ratio and cosine similarity were used to evaluate repeatability of EMG waveforms between visits. Nonnegative matrix factorization was used to calculate synergies from EMG data at each visit to compare synergy weights and activations.

Results & significance: The inter-visit variance ratios of EMG data for children with CP were similar to previously reported results for typically-developing children and unimpaired adults (range: 0.39 for vastus lateralis to 0.66 for rectus femoris). The average cosine similarity of the EMG waveforms between visits was greater than 0.9 for all muscles, while synergy weights and activations also had high similarity – greater than 0.8 and 0.9 between visits, respectively. These results demonstrate that EMG repeatability between visits during clinical gait analysis for children with CP is similar to unimpaired individuals. These results provide a baseline for evaluating whether observed changes in EMG recordings between visits reflect real changes in muscle activity or are within the range of inter-visit variability.

BR Shuman, M Goudriaan, K Desloovere, MH Schwartz, KM Steele (2018) “Associations Between Muscle Synergies and Treatment Outcomes in Cerebral Palsy Are Robust Across Clinical Centers.” Archives of Physical Medicine and Rehabilitation

Journal article in Archives of Physical Medicine and Rehabilitation:

In collaboration with Gillette Children’s Hospital and University Hospital Pellenberg we examined whether associations between treatment outcomes and muscles synergies are robust between clinical centers.

Objective: To determine whether patient-specific differences in motor control quantified using muscle synergy analysis were associated with changes in gait after treatment of cerebral palsy (CP) across 2 clinical centers with different treatments and clinical protocols.
Design: Retrospective cohort study.
Setting: Clinical medical center.
Participants: Center 1: children with CP (n=473) and typically developing (TD) children (n=84). Center 2: children with CP (n=163) and TD children (n=12).
Interventions: Standard clinical care at each center.
Main outcome measures: The Dynamic Motor Control Index During Walking (walk-DMC) was computed from electromyographic data during gait using muscle synergy analysis. Regression analysis was used to evaluate whether pretreatment walking speed or kinematics, muscle synergies, treatment group, prior treatment, or age were associated with posttreatment changes in gait at both clinical centers.
Results: Walk-DMC was significantly associated with changes in speed and kinematics after treatment with similar regression models at both centers. Children with less impaired motor control were more likely to have improvements in walking speed and gait kinematics after treatment, independent of treatment group.
Conclusions: Dynamic motor control evaluated with synergy analysis was associated with changes in gait after treatment at both centers, despite differences in treatments and clinical protocols. This study further supports the finding that walk-DMC provides additional information, not captured in traditional gait analysis, that may be useful for treatment planning.

Alyssa Spomer and Momona Yamagami Present at a Neurorehabilitation Conference in Spain

Alyssa and Momona attended the Summer School on Neurorehabilitation (SSNR) in Baiona, Spain from September 16th to the 21st. Alyssa gave a podium presentation on a feedback system she is developing that aims to characterize and target altered motor control in cerebral palsy. Momona gave a poster presentation to share her recent quantifications of deficits in motor planning in cerebral palsy. Nice work, Alyssa and Momona!Alyssa at podium presenting "A Feedback System to Characterize and Target Altered Motor Control in Cerebral Palsy".

 

 

Monoma stands in front of her poster "Quantification of Deficits in Motor Planning in Cerebral Palsy", discussing with interested colleagues.

 

Research Experience Undergraduates Present at CSNE

This summer the Steele Lab had the pleasure of hosting three undergraduate researchersJulia Costacurta from Johns Hopkins, Joe Lawler from the University of Washington, and Preston Pan from the 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 Julia, Joe, and Preston for their successful time here in the lab, and for giving polished presentations.

Three undergraduates, in their early twenties, stand arm in arm as they smile for the photo. They are dressed in business casual attire and behind them hangs a series of scientific posters on biomechanics.

Julia’s work explored the impacts of Ankle-Foot Orthoses on transient gait, a period of walking where little is currently known about device dynamics.

Julia Costacurta and her mentor for the 2018 summer, Michael Rosenberg, stand in front of her scientific poster evaluating the impact of ankle foot orthosis stiffness on transient walking.Preston worked directly with Seattle Children’s Hospital to implement algorithms for detecting bimanual hand movement before, during, and after a common therapy used to promote improved motor skills for children with hemiplegic cerebral palsy.

Preston Pan, in a white collared shirt and blazer, stands in front of his scientific poster evaluated a proposed motion tracking algorithm for bimanual movement.

Joe’s focus this summer involved working with the University of Washington HuskyADAPT program. HuskyADAPT is a student-run program in its second year and stands for Accessible Design and Play Technology. Joe’s research question asked, how we can improve upon and further promote an inclusive and sustainable program for assistive technology?