Evaluation of an activity monitor for the objective measurement of free-living physical activity in children with cerebral palsy.
OBJECTIVE
To explore the use of an activity monitor (AM) to objectively characterize free-living physical activity (F-LPA) in children with mobility impairment resulting from cerebral palsy (CP).


METHODS
First, a validation study compared outcomes from the AM with video evidence. Second, multiday F-LPA was characterized. Relationships between laboratory measures and F-LPA were explored.


METHODS
The evaluation study was conducted in a laboratory environment. F-LPA monitoring was conducted in the participants' free-living environment.


METHODS
Convenience sample of ambulatory children (N=15; 11 boys, 4 girls) aged 5 to 17 years with CP undergoing gait analysis.


METHODS
Not applicable.


METHODS
Accuracy of the AM for sitting/lying time, upright time, stepping time, and strides taken. Daily volumes of F-LPA of children with CP.


RESULTS
AM outcomes in comparison with video-based analysis were (mean ± SD) 97.4%±2.7%, 101.1%±1.5%, 99.5%±6.6%, 105.6%±15.8%, and 103.8%±10.1% for sitting/lying time, upright time, standing time, stepping time, and stride count, respectively. Participants' daily F-LPA demonstrated considerable variation: mean standing time ± SD, 2.33±.96h/d; mean stepping time ± SD, 1.68±.86h/d; mean steps per day ± SD, 8477±4528; and mean sit-to-stand transitions per day ± SD, 76±49. Laboratory-measured cadence and mobility level were related to F-LPA, but not directly.


CONCLUSIONS
The AM demonstrated excellent ability to determine sitting/lying and upright times in children with CP. Stepping time and stride count had lower levels of agreement with video-based analysis but were comparable to findings in previous studies. Crouch gait and toe walking had an adverse effect on outcomes. The F-LPA data provided additional information on children's performance not related to laboratory measures, demonstrating the added value of using this objective measurement technique.
Bioengineering Unit, University of Strathclyde, Wolfson Centre, Glasgow, Scotland; Medical Physics and Clinical Engineering, St. James Hospital, Leeds, England.
Kit Tzu
KT
Tang
Anderson Gait Analysis Laboratory, Edinburgh, Scotland.
Alison M
AM
Richardson
PAL Technologies Ltd, Glasgow, Scotland.
Douglas
D
Maxwell
Bioengineering Unit, University of Strathclyde, Wolfson Centre, Glasgow, Scotland; WD Spence Prosthetics Ltd, Pitlochry, Perthshire, Scotland.
William D
WD
Spence
School of Health and Life Sciences, Glasgow Caledonian University, Glasgow, Scotland. Electronic address: ben.stansfield@gcu.ac.uk.
Benedict W
BW
Stansfield
D061725:Accelerometry / Q000295:instrumentation*; D000293:Adolescent; D002547:Cerebral Palsy / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D051346:Mobility Limitation; D009043:Motor Activity / Q000502:physiology*
AM; CP; Cerebral palsy; Child; F-LPA; FAQ; GMFCS; Gillette Functional Assessment Questionnaire; Gross Motor Function Classification System; Monitoring; Motor activity; NHS; National Health Service; Rehabilitation; STS; activity monitor; adolescent; ambulatory; cerebral palsy; free-living physical activity; sit-to-stand