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

Purpose: 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 female; mean age: 33.5 yr, SD 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 level IV-V) differed from ambulatory adults (GMFCS level 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 level II-V.