Wheelchair users' perceived exertion during typical mobility activities

Abstract

Study Design: Each participant performed a series of wheelchair exercises equivalent in intensity to minimal functional speed (1 m s-1), functional walking speed (1.3 m s-1), a relatively challenging speed (1.6 m s-1) and a self-selected speed. Each participant also completed a graded exercise test (GXT) to volitional exhaustion (VO2peak). Objectives: The purpose of this study was (1) to assess the physical capacity of wheelchair users as they undertake typical mobility activities and (2) to investigate how closely the components of a differentiated model of perceived exertion mirror wheelchair users' own perception of exertion. Methods: Eleven (eight males and three females) spinal cord-injured or congenitally impaired wheelchair-dependent participants volunteered for the study. Differentiated ratings of perceived exertion (RPE-arm and RPE-respiration) and oxygen uptake (VO2) and heart rate were recorded during each exercise. Results: The mean comfortable speed at which the participants propelled their own wheelchairs on the wheelchair ergometer was 1.1±0.2 m s-1. Speeds of 1 m s-1 and 1.3 m s-1 are typical of everyday functional propulsion. The corresponding RPE-respiration and RPE-arm ranged from 7 to 13 on the Borg scale; the %VO2peak measured in these trials ranged from 37 to 80% VO2peak. For propulsion intensities used in the present study - low, moderate, high and graded exercise intensity - no difference could be observed between RPE-respiration and RPE-arm. There were no significant differences between RPE-arm and RPE-respiration at the termination of the GXT. Conclusion: The current study showed potential for the use of RPE to assess and monitor daily wheelchair propulsion intensity in individuals with paraplegia.