Physical strain of walking in people with neuromuscular diseases is high and relates to step activity in daily life

Abstract

Objective: To determine the physical strain of walking and assess its relationship with daily steps and intensity of daily activity in people with neuromuscular diseases. Design: Cross-sectional study. Subjects/patients: Sixty-one adults with neuromuscular diseases. Methods: Physical strain of walking, defined as oxygen consumption during comfortable walking relative to peak oxygen uptake. Daily step count and daily time spent in moderate and vigorous physical activity were assessed using accelerometry and heart rate measurements, respectively. Regression analyses assessed the relationships between log daily step count and log daily time spent in moderate and vigorous physical activity, and physical strain of walking. Results: The mean (standard deviation) physical strain of walking was 73 (20)% Log daily step count and physical strain were negatively associated (β = –0.47). No association was found with log daily time spent in moderate and vigorous physical activity. Conclusions: The highly increased physical strain of comfortable walking indicates that walking is very demanding for people with neuromuscular diseases and is associated with a reduction in daily step activity. The absence of a relationship between intensity of activities and physical strain indicates that, despite a reduction in daily step activity, strenuous daily activities may still be performed.