Early Intervention

ME Hoffman, R Abuatiq, K Bokowy, AL Fiss, J Looper, KM Steele (2026) “Up and down: analyzing physical activity and posture with wearable sensors during partial bodyweight supported play for young children with down syndrome”

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Journal Article in Developmental Neurorehabilitation

Children with Down syndrome commonly experience delays in motor milestones, such as pulling to stand and walking, due to musculoskeletal factors associated with DS like hypotonia and ligament laxity

Aim: Understanding how to support age-appropriate motor exploration while increasing movement, physical activity and upright time is essential for optimizing developmental and health outcomes in young children with Down syndrome. Open-area partial bodyweight support (PBWS) systems can help support motor development, but no study has objectively reported motor behavior changes, such as increased leg activity or time spent upright.  

Methods: This randomized, multisite crossover trial included children with Down syndrome who could sit independently but were not yet walking. Each child completed nine 30-minute play-based sessions with and without PBWS. Physical activity and posture were measured using shank-worn accelerometers, capturing the percentage of time spent in high physical activity and upright. Nonparametric Mann-Whitney U tests compared outcome measures between PBWS and non-PBWS conditions.

Results: Fifteen children (mean age: 19.4 months, range: 12–31 months) completed study procedures. Across all participants, high physical activity did not noticeably increase from the first to last session. The median change was −5.0% (IQR: −13.4- +9.05%) with PBWS and −2.53% (IQR: −13.7- +12.9%) without PBWS. Time spent on feet showed a median increase of +2.38% with PBWS (IQR: −0.96 – +12.24) and a decrease of −1.08% without PBWS (IQR: −7.70 - + 1.02%). A statistically significant difference between conditions (p = .042) indicated greater improvements in time on feet during PBWS sessions versus without.

Interpretation: PBWS did not increase time spent in high physical activity, but did support increased upright posture over time. These findings suggest PBWS systems may provide a supportive environment for practicing upright postures in early motor development for children with Down syndrome.

(A) The enriched exploratory play space with the PBWS system (B) Actigraph GT3X+ triaxial accelerometers were placed on a child’s right shank. (C) This study used a randomized crossover study design. Nine children had PBWS assistance first, and 6 children second. Each intervention period lasted 3 weeks. (D) The accelerometers were used to calculate physical activity and upright posture.

HA Feldner, K Keithley, KA Ingraham, A Fragomeni, N Zaino, A Sinclair, AN Meltzoff, PK Kuhl, KM Steele (2026) “Learning powered mobility: caregiver perceptions of young children’s capabilities and device impact”

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Journal Article in Disability and Rehabilitation: Assistive Technology

Self-initiated mobility experiences are critical for young children with disabilities and may be augmented through powered mobility.

(A) A child participant driving the Permobil ® Explorer Mini (photo courtesy of the IMPACT Collaboratory). (B) Specifications of the Explorer Mini device.

Aim: The purpose of this study was to understand caregiver perceptions of powered mobility intervention following a 12-session trial of a novel powered mobility device.  

Methods: Ten caregivers (4 M/6F) of children with cerebral palsy (Gross Motor Function Classification System IV-V) and other developmental disabilities (21.8 ± 5.9 months). Children participated in 12 in-lab driving sessions (exploratory or goal directed) using the Explorer Mini (Permobil AB, Sweden). Exit interviews were conducted with caregivers at the final visit, transcribed verbatim, coded inductively, and analysed until themes emerged.

Results: Four themes emerged from the data: (1) Changing views of capability and adaptability; (2) Emerging autonomy; new skills in and out of the device; (3) Clear need and benefit with some drawbacks; and (4) Lingering stigma and uncertainty 

Interpretation: PM trial positively shifted caregiver’s perceptions of both PM in general and their child’s capabilities, with a desire for greater access to PM at home to support development. These beliefs remained juxtaposed with lingering stigma for some caregivers about PM devices, and a stated desire for more modifiable PM options for children with different positioning or access needs.

Congratulations to Dr. Mia Hoffman – 2026 Graduate School Medal Recipient!

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Huge congratulations to Dr. Mia Hoffman, recipient of the University of Washington’s 2026 Graduate School Medal – awarded to doctoral graduates whose research and civic engagement drive real social change.

Mia’s dissertation grew out of a simple question: how could a toddler with cerebral palsy play alongside her sibling? That question led to the Switch Kit, a low-cost, customizable system that helps children with motor disabilities engage in play, co-designed with families, clinicians, and speech-language pathologists. Her leadership of HuskyADAPT helped bring adapted toys to families across Washington State.

Mia earned her Ph.D. in Mechanical Engineering, co-advised by our own Dr. Kat Steele and Dr. Heather Feldner, and was also named to this year’s Husky 100. She’s headed to Ohio State for a postdoctoral fellowship, and eventually hopes to launch her own lab focused on mobility, accessibility, and play.

Congratulations, Dr. Hoffman – we can’t wait to see what’s next!

Read the full feature from the UW Graduate School.

Mia has long straight blonde hair and is wearing a white and black striped blazer on a balcony

Neuromechanics & Mobility Lab at the 2026 Undergraduate Research Symposium

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Congratulations to the Neuromechanics & Mobility Lab undergraduates who presented their research at the University of Washington’s 29th Annual Undergraduate Research Symposium on May 15! From oral presentations to posters, our students shared work spanning early mobility, gait analysis, and neuromodulation — proud moment for the whole lab.

Oral Presentations

Early Intervention Providers’ Perspectives on a Switch-Accessible Play Kit Analyzed Through an Interdependence Framework Alisha Bose (mentored by Mia Hoffman)

Muscular Coactivation Analysis in Toddlers with Hypotonia Spencer Hensley (mentored by Mia Hoffman)

Poster Presentations

Real-Time Bayesian Estimation of Steady-State Oxygen Consumption During Clinical Walking Trials for Neuromuscular-Impaired Individuals David Green (mentored by Mackenzie Pitts)

Object Detection Optimization for Movement Tracking of Young Children Using Mobility Aids Katie Leija (mentored by Mia Hoffman)

Effects of Bodyweight Support on the Gait Deviation Index of Children with Cerebral Palsy Alyssa Miller (mentored by Ally Clarke)

Evaluating the Effects of Transcutaneous Spinal Cord Stimulation on Perceived Walking Performance and Exertion in Children with Cerebral Palsy Quinn Mundell (mentored by Madeleine McCreary)

Huge thanks to the graduate student mentors who supported these projects, and congratulations to all our presenters on a fantastic symposium!

Introducing Dr. Mia Hoffman!

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Congratulations to Dr. Mia Hoffman on earning a Doctorate in Mechanical Engineering!

Dr. Hoffman’s PhD dissertation was titled “Pathways to self‑initiated mobility: Adoption and use of mobility aids by young children with developmental disabilities.” Her work advanced understanding of how early mobility supports can promote exploration, participation, and development for children with disabilities.

Congratulations and best of luck as Mia moves forward as a President’s Postdoctoral Scholar at The Ohio State University, working with Dr. Jill Heathcock in the School of Health and Rehabilitation Sciences in the College of Medicine!