Energy expenditure and muscle activity during lying, sitting, standing, and walking in people with motor-incomplete spinal cord injury

Abstract

Study design: Cross-sectional exploratory study. Objectives: To determine oxygen uptake (VO 2 ), energy expenditure (EE), and muscle activity (MA) during lying (rest), sitting, standing, and walking among ambulatory individuals with spinal cord Injury (SCI) and to compare VO 2 , EE, and MA between individuals with different levels of ambulation. Setting: Rehabilitation institution with a spinal cord injury unit. Methods: A total of 22 adults with motor-incomplete SCI, ten in a low-ambulation group (non-functional or household walker) and 12 in a high-ambulation group (community or normal walker). VO 2 was measured using indirect calorimetry. EE was expressed in metabolic equivalent of task (MET). MA was measured using a wireless surface electromyography device. Results: Mean VO 2 was 3.19 ml/kg/min. During lying and sitting, EE was below 1.5 METs for all participants. During standing, three participants of the low-ambulation group and none in the high-ambulation group showed MET values of >1.5. In the walking condition, all participants showed MET values above 1.5. MA during stance was higher compared to the sitting condition and significantly higher in the low-ambulation group compared to the high-ambulation group. Conclusion: Lying, supported- and unsupported sitting, without moving, appear to be sedentary behaviors for ambulatory individuals with a motor-incomplete SCI (MET values of <1.5 and a lack of MA). Walking, but not standing, is a moderate physical activity (>1.5 METs), which can be used by all individuals with motor-incomplete SCI to interrupt sedentary behavior.