Influence of age on step activity patterns in children with cerebral palsy and typically developing children.

OBJECTIVE

To document the influence of age on step activity patterns in children with cerebral palsy (CP) and typically developing (TD) children.

DESIGN

Cross-sectional.

SETTING

All step activity data were collected in free-living environments.

PARTICIPANTS

Children with CP (n=27; age, 4-18y; 22 boys, 5 girls; Gross Motor Function Classification System levels I and II) and 27 age- and sex-matched TD children were recruited through public advertisements and contacts with local clinicians. CP and TD participants were stratified into younger (<10y; n=14) and older (10-18y; n=13) age groups.

INTERVENTION

Daily step activity was monitored using a step activity monitor that was individually programmed to account for the gait characteristics of each participant. Step activity data were collected in 1-minute epochs during waking hours on 3 weekdays and 1 weekend day. Stored data were analyzed to yield average values of daily step activity, percentage of inactive time (0 steps) over the entire day, and percentage of total daily active time spent in low step activity (1-15 steps/min), medium step activity (16-40 steps/min), and high step activity (>40 steps/min).

MAIN OUTCOME MEASURES

Daily step activity, percentage of inactive time, and percentage of active time spent in low-, moderate-, and high-intensity step activity.

RESULTS

A significant (P<.05) interaction was observed between age (younger, older) and condition (CP, TD) for daily step activity, percentage of inactive time, and percentage of active time spent in low- and high-intensity step activity. The main effect of age was significant for each physical activity measure except for relative high-intensity step activity, and the main effect of condition was significant for all physical activity measures. Follow-up analyses (P<.025) revealed that older children with CP took fewer daily steps and displayed higher relative levels of inactivity and low-intensity activity and lower relative levels of high-intensity activity compared with older TD children. Older children with CP also exhibited lower daily step activity, demonstrated higher relative levels of inactivity and low-intensity activity, and displayed lower relative levels of moderate-intensity activity compared with younger children with CP.

CONCLUSIONS

Compared with younger children with CP and age- and sex-matched TD youth, older youth with CP generally displayed step activity patterns typified by lower levels of physical activity and a greater degree of inactivity. These findings highlight the need to provide multiple opportunities for adolescents with CP to engage in a variety of physical activities that are appropriate to their needs, abilities, and preferences and that can aid in maintaining functional mobility, health, and quality of life.