Engineering to enhance human mobility, play, and exploration
Congratulations to Jessica for being acknowledged by the Department of Mechanical Engineering for her academic achievements and potential for success within her masters studies.
Jessica is dedicated to creating a pediatric exoskeleton which promotes improved walking patterns during daily life, outside of therapy sessions. This fellowship will allow Jessica to devote more time towards her research and studies. Congrats!
Here at the Ability & Innovation Lab we are fortunate to partner with amazing families and people who are our user experts for feedback and ideas when creating new devices and designs. Jayna and her family are fantastic partners in the design project for Jayna, alongside our undergraduate students. The second prototype is now underway to improve the comfort, donning and doffing, and applicability of Jayna’s elbow-driven device to enable the use of her left arm during two handed tasks.
UW Together presents Jayna’s story HERE.
Interested in how technology can be used to make a difference in pediatric rehabilitation? A video cast from the National Center for Medical Rehabilitation Research (NCMRR) discusses the topic in Bethesda MD. The workshop is organized by the Motion Analysis Laboratory and supported by the National Science Foundation and the National Institutes of Health.
The workshop on August 9th, 2016 brought together a group of experts in rehabilitation to discuss how technology can help us to address pressing needs in pediatric rehabilitation. To follow all of the talks this past week and listen to “Can Technology Make a Difference in Pediatric Rehabilitation?”, follow this link, CLICK HERE.
Peer-reviewed paper at IEEE Engineering in Medicine & Biology Annual Conference:
Can we estimate upper-extremity force production from electrocorticographic recordings?
Abstract: Neural correlates of movement planning onset and direction may be present in human electrocorticography in the signal dynamics of both motor and non-motor cortical regions. We use a three-stage model of jPCA reduced-rank hidden Markov model (jPCA-RR-HMM), regularized shrunken-centroid discriminant analysis (RDA), and LASSO regression to extract direction-sensitive planning information and movement onset in an upper-limb 3D isometric force task in a human subject. This mode achieves a relatively high true positive force-onset prediction rate of 60% within 250ms, and an above-chance 36% accuracy (17% chance) in predicting one of six planned 3D directions of isometric force using pre-movement signals. We also find direction-distinguishing information up to 400ms before force onset in the pre-movement signals, captured by electrodes placed over the limb-ipsilateral dorsal premotor regions. This approach can contribute to more accurate decoding of higher-level movement goals, at earlier timescales, and inform sensor placement. Our results also contribute to further understanding of the spatiotemporal features of human motor planning.
Journal article in Prosthetics & Orthotics International:
How does the operating length of the gastrocnemius vary with different common AFOs in children with cerebral palsy?
Background: Many individuals with cerebral palsy wear ankle foot orthoses during daily life. Orthoses influence joint motion, but how they impact muscle remains unclear. In particular, the gastrocnemius is commonly stiff in cerebral palsy. Understanding whether orthoses stretch or shorten this muscle during daily life may inform orthosis design and rehabilitation.
Objectives: This study investigated the impact of different ankle foot orthoses on gastrocnemius operating length during walking in children with cerebral palsy.
Study design: Case series, within subject comparison of gastrocnemius operating length while walking barefoot and with two types of ankle foot orthoses.
Methods: We performed gait analyses for 11 children with cerebral palsy. Each child was fit with two types of orthoses: a dynamic ankle foot orthosis (Cascade dynamic ankle foot orthosis) and an adjustable dynamic response ankle foot orthosis (Ultraflex ankle foot orthosis). Musculoskeletal modeling was used to quantify gastrocnemius musculotendon operating length and velocity with each orthosis.
Results: Walking with ankle foot orthoses could stretch the gastrocnemius more than barefoot walking for some individuals; however, there was significant variability between participants and orthoses. At least one type of orthosis stretched the gastrocnemius during walking for 4/6 and 3/5 of the Gross Motor Functional Classification System Level I and III participants, respectively. AFOs also reduced peak gastrocnemius lengthening velocity compared to barefoot walking for some participants, with greater reductions among the Gross Motor Functional Classification System Level III participants. Changes in gastrocnemius operating length and lengthening velocity were related to changes in ankle and knee kinematics during gait.
Conclusion: Ankle foot orthoses impact gastrocnemius operating length during walking and, with proper design, may assist with stretching tight muscles in daily life.
Clinical relevance: Determining whether ankle foot orthoses stretch tight muscles can inform future orthotic design and potentially provide a platform for integrating therapy into daily life. However, stretching tight muscles must be balanced with other goals of orthoses such as improving gait and preventing bone deformities.