Walk-DMC – Kat Steele and Michael Schwartz are featured in GeekWire

A staff member of a gait lab kneels next to a child to apply additional motion detecting markers at Gillette Children's Specialty Healthcare. Another staff member sits behind a desk, observing the instrumentation on the lab computer. Photo taken by Michael Schwartz.

GeekWire, a national technology news resource, has featured Dr. Steele and Dr. Schwartz‘s Walk-DMC in a special series focused on community issues and innovative solutions to societal challenges. Lisa Stiffler reports on the analysis that is used to create Walk-DMC, an assessment tool that uses routinely collected electromyography (EMG) data to identify which kids are the strongest candidates for surgery — and to help develop alternative treatments for children needing a different solution.

“It’s a very complex problem,” said Steele, who is a co-author of a paper explaining the Walk DMC metric published this month in the journal Developmental Medicine & Child Neurology. “You can have two individuals who are walking visually nearly identically,” she said, “but how they’re controlling that motion can be very different.”

To read the full article, click HERE.

EE Bulter, KM Steele, L Torburn, JG Gamble, J Rose (2016) “Clinical motion analyses over eight consecutive years in a child with crouch gait: a case report.” Journal of Medical Case Reports

Sagittal-plane images of child from 6-13 years of age.

Journal article in the Journal of Medical Case Reports:

A case study of crouch gait over 8-years in a child with no surgical interventions.

Sagittal-plane images of child from 6-13 years of age.

Background: This case report provides a unique look at the progression of crouch gait in a child with cerebral palsy over an 8-year time period, through annual physical examinations, three-dimensional gait analyses, and evaluation of postural balance. Our patient received regular botulinum toxin-A injections, casting, and physical therapy but no surgical interventions.

Case presentation: A white American boy with spastic diplegic cerebral palsy was evaluated annually by clinical motion analyses, including physical examination, joint kinematics, electromyography, energy expenditure, and standing postural balance tests, from 6 to 13 years of age. These analyses revealed that the biomechanical factors contributing to our patient’s crouch gait were weak plantar flexors, short and spastic hamstrings, moderately short hip flexors, and external rotation of the tibiae. Despite annual recommendations for surgical lengthening of the hamstrings, the family opted for non-surgical treatment through botulinum toxin-A injections, casting, and exercise. Our patient’s crouch gait improved between ages 6 and 9, then worsened at age 10, concurrent with his greatest body mass index, increased plantar flexor weakness, increased standing postural sway, slowest normalized walking speed, and greatest walking energy expenditure. Although our patient’s maximum knee extension in stance improved by 14 degrees at 13 years of age compared to 6 years of age, peak knee flexion in swing declined, his ankles became more dorsiflexed, his hips became more internally rotated, and his tibiae became more externally rotated. From 6 to 9 years of age, our patient’s minimum stance-phase knee flexion varied in an inverse relationship with his body mass index; from 10 to 13 years of age, changes in his minimum stance-phase knee flexion paralleled changes in his body mass index.

Conclusions: The motor deficits of weakness, spasticity, shortened muscle-tendon lengths, and impaired selective motor control were highlighted by our patient’s clinical motion analyses. Overall, our patient’s crouch gait improved mildly with aggressive non-operative management and a supportive family dedicated to regular home exercise. The annual clinical motion analyses identified changes in motor deficits that were associated with changes in the child’s walking pattern, suggesting that these analyses can serve to track the progression of children with spastic cerebral palsy.

Featured in UWToday: Michael Schwartz and Kat Steele have developed a quantitative assessment of motor control in children with cerebral palsy

A child walking in the motion analysis lab at Gillette Children's Specialty Healthcare. Photo by Michael Schwartz.

Our lab’s director, Dr. Kat Steele, and Dr. Michael Schwartz, from Gillette Children’s Specialty Healthcare, have developed a quantitative assessment of motor control in children with cerebral palsy called Walk-DMC, which could be used to help determine whether or not patients would benefit from aggressive, invasive surgeries to assist in walking and motion. Jennifer Langston reports on the new technique within UWToday. An exert from the article is posted below, but for the full article, read HERE.

“Only about 50 percent of children have significant improvement in their movement after these highly invasive surgeries,” said Kat Steele, a UW assistant professor of mechanical engineering. “Our motivation has really been to figure out how we can push up these success rates.”

MH Schwartz, A Rozumalski, KM Steele (2016) “Dynamic motor control is associated with treatment outcomes for children with cerebral palsy.” Developmental Medicine & Child Neurology

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