Physical Strain of Walking Relates to Activity Level in Adults With Cerebral Palsy

Objective: To gain insight into underlying mechanisms of inactive lifestyles among adults with spastic bilateral cerebral palsy (CP) with a focus on aerobic capacity, oxygen consumption, and physical strain during walking at preferred walking speed, as well as fatigue. Design: Cross-sectional. Setting: University hospital. Participants: Adults (N=36), aged 25 to 45 years, with spastic bilateral CP, walking with (n=6) or without (n=30) walking aids. Interventions: Not applicable. Main Outcome Measures: Physical strain during walking was defined as oxygen uptake during walking, expressed as percentage of peak aerobic capacity. Participants with spastic bilateral CP walked their preferred walking speed while oxygen uptake was measured using a portable gas analyzer. Peak aerobic capacity was measured during maximal cycle ergometry. An accelerometry-based activity monitor measured total daily walking time. Regression analyses were performed to assess the relation between aerobic capacity, oxygen uptake, and physical strain of walking on the one hand and total daily walking time on the other hand. Results: Neither aerobic capacity nor oxygen uptake during walking was related to total daily walking time (r(2)=.29, P=.10 and r(2)=.27, P=.16, respectively). Physical strain of walking at preferred walking speed was inversely related to total daily walking time (r(2)=.44, P<.01). Conclusions: Physical strain during walking is moderately related to total daily walking time, implying that people with high physical strain during walking at preferred walking speed likely walk less in daily life. Archives of Physical Medicine and Rehabilitation 2013;94:896-901 (C) 2013 by the American Congress of Rehabilitation Medicine