Wheelchair users' perceived exertion during typical mobility activities

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). 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. 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. 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. The current study showed potential for the use of RPE to assess and monitor daily wheelchair propulsion intensity in individuals with paraplegia.