The reliability and validity of a research-grade pedometer for children and adolescents with cerebral palsy.

AIM The aim of this study was to determine the reliability, validity, and optimal placement of pedometers in children with cerebral palsy (CP) who ambulate without aids. METHOD Seventeen participants aged 7 to 17 years with CP (eight males, nine females; mean age 12y 4mo; SD 3y 2mo), who could ambulate without aids, wore four New Lifestyles pedometers (NL-1000) on an elasticized waist belt. Fourteen participants had hemiplegia, two diplegia, and one triplegia; all were classified in Gross Motor Function Classification System (GMFCS) level I (n=8) or II (n=9). Participants completed 3-minute walking and running trials around an indoor course and were videotaped to verify the actual number of steps taken during each trial. Inter-pedometer reliability was determined by comparing pedometer readings using intraclass correlation coefficients (ICCs). Validity was determined by comparing pedometer step counts with video step counts using ICC, t-tests, and Bland-Altman plots. Optimal pedometer placement was determined using Wilcoxon signed-rank tests to compare the percentage error for pedometers positioned on the dominant and non-dominant hips. RESULTS Excellent reliability (ICC 0.88-0.99) and validity (ICC 0.78-0.95) were demonstrated with no significant difference between the video step counts and pedometer step counts. There was no significant difference between the step counts recorded by pedometers on the dominant and non-dominant hips. INTERPRETATION This study showed that NL-1000 pedometers have a high degree of reliability and validity in ambulant children with CP in controlled conditions.