title: Quantification of Physical Activity and Sedentary Time in Adults with Cerebral Palsy.
abstract: OBJECTIVE
  The purpose of this study was to determine objective and subjective quantification of habitual physical activity (HPA) and sedentary time in ambulatory and nonambulatory adults with cerebral palsy (CP).
  
  
  METHODS
  We recruited a clinical sample of adults with CP (N = 42; 21 women; mean (SD) age, 33.5 (12.3) yr; Gross Motor Function Classification System (GMFCS) distribution: level I (n = 5), level II (n = 9), level III (n = 10), level IV (n = 11), and level V (n = 7). Objective measures of HPA and sedentary time were obtained by using ActiGraph GT3X accelerometers at both hip and wrist sites. Three previously established cut-point values distinguishing light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA) were evaluated across GMFCS levels. The concurrent validity of the self-report Physical Activity Recall Assessment for People with Spinal Cord Injury (PARA-SCI) was assessed for LPA and MVPA intensities in GMFCS levels II-V.
  
  
  RESULTS
  Participants showed little reluctance to wearing accelerometers; one participant reported discomfort. Nonambulatory adults (GMFCS levels IV-V) differed from ambulatory adults (GMFCS levels I-III) for recorded activity counts (hip and wrist sites), minutes of MVPA with each cut-point value, and breaks from sedentary time (all P < 0.05). For the same measures, adults in GMFCS level III also differed from GMFCS level I (all P < 0.05). The PARA-SCI correlated significantly with accelerometer-derived minutes of MVPA per day (r = 0.396; P = 0.014) and per hour of monitoring time (r = 0.356; P = 0.027).
  
  
  CONCLUSIONS
  Our findings support the use of accelerometers to objectively measure HPA and sedentary behavior in adults with CP across the severity spectrum, regardless of cut-point implementation. The PARA-SCI is a valid tool to capture subjectively reported patterns of MVPA in adults with CP who are GMFCS levels II-V.
authors.affiliation: 1CanChild Centre for Childhood Disability Research, McMaster University, Hamilton, Ontario, CANADA; 2Department of Kinesiology, McMaster University, Hamilton, Ontario, CANADA; and 3Child Health & Exercise Medicine Program, Department of Pediatrics, McMaster University, Hamilton, Ontario, CANADA.
authors.forename: Everett A
authors.initials: EA
authors.lastname: Claridge
authors.forename: Patrick G
authors.initials: PG
authors.lastname: McPhee
authors.forename: Brian W
authors.initials: BW
authors.lastname: Timmons
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Martin Ginis
authors.forename: Maureen J
authors.initials: MJ
authors.lastname: Macdonald
authors.forename: Jan Willem
authors.initials: JW
authors.lastname: Gorter
mesh_terms: D056044:Actigraphy / Q000295:instrumentation; D000328:Adult; D002547:Cerebral Palsy; D006233:Persons with Disabilities; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity; D057185:Sedentary Behavior; D013997:Time Factors; D055815:Young Adult