Quantification of Physical Activity and Sedentary Time in Adults with Cerebral Palsy

PURPOSE: 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.