Research Report
Population: Pediatric
Kristie Bjornson, PT, PhD, Associate Professor, Seattle Children’s Research Institute, University of Washington kristie.bjornson@seattlechildrens.org
Philip Hurvitz, PhD, Research Assistant Professor, University of Washington phurvitz@uw.edu
Cheryl Kerfeld, PT, PhD, Acting Assistant Professor, University of Washington ckerfe@uw.edu
Keywords: Participation, Activity, Walking, Cerebral palsy
Purpose/Hypothesis
Ambulatory children with cerebral palsy (CP) demonstrate significant limitations in their community-based walking activity and participation. Community participation to date has been sampled primarily through questionnaires. We describe a novel combination of accelerometry-based walking activity and global positioning system (GPS) to quantify the walking and community participation of children with CP with/without assistive device at home versus in the community.
Subjects
A total of 6 children with bilateral CP & Gross Motor Function Classification System Levels I=1, II=3, III=2 (5.0-11.1 yrs, 3 girls) participated. There were 4 independent walkers (IW) and 2 assisted walkers (AW).
Materials/Methods
Participants wore the StepWatch (SW) accelerometer on the left ankle and GPS on the other ankle all waking hours for 7 days. SW documented total time and bouts walking/day. Bouts consisted of blocks of at least 3 minutes walking, and were grouped if separated by up to two minutes of non-walking. Synchronized SW & GPS data quantified distance walked and % time at home or in the community walked/day by low (1-30 strides/min), medium (31-60 strides/min) and high (> 60 strides/min) rates. Sustained walking was defined as at least 3 minutes of non-walking (non-walk = 0 strides). Maps of location by stride rates for one day of walking activity of an IW and an AW captures where in the community relative to home the child is walking.
Results
Time walking each day averaged 204.5 (51.4) and 124.3 (12.2) minutes for IW and AW respectively. Distance walked averaged 8.5 (6.2) kilometers for IW and 2.5 (1.6) for AW. Of all walking time, IW averaged 13.6 (3.7) walking bouts with 17.4 (6.5) for AW. Of those bouts, 12.5 and 16 respectively, were in medium stride ranges. IW spent 16.3% of walking time at home and 16.3% in the community, while AW spent 4.5% and 18.5% respectively. For example, an IW displays a broad range of walking relative to home for one day with 4 points of medium stride rate activity which occur at home, school, and baseball fields in the region. In contrast, the AW demonstrates less range of walking activity from home with 1 point of moderate stride rate activity occurring at home and low stride rates at a neighborhood park.
Conclusion
Ambulatory children with CP who are AW demonstrated lower distance and levels of community walking than IW. Synchronized walking and GPS data has potential to quantify community-based walking activity and participation.
Clinical Relevance
Mapping of the combined accelerometry and GPS data allows for qualitative analysis of personal and environmental factors which influence community-based walking activity and participation. This methodology appears sensitive to the expected community mobility levels for IW versus AW. Further work is warranted to validate this novel methodology to other measures of mobility–based community participation.
Citation:
Bjornson, Kristie , PT, PhD; Hurvitz, Philip M., PhD; Kerfeld, Cheryl I., PT, PhD. Community Walking Activity in Cerebral Palsy: StepWatch & Global Positioning System (GPS).. Poster Presentation. IV STEP Conference, American Physical Therapy Association, Columbus, OH, July 17, 2016. Online. https://u.osu.edu/ivstep/poster/abstracts/020_bjornson-et-al/