Cardiorespiratory and Perceptual Responses to Arm Crank and Wheelchair Exercise Using Various Handrims in Male Paraplegics

Abstract

The purpose of the present study was to determine the effects of 10-in [025–m] versus 16-in [0.41-m] wheelchair handrims on cardiorespiratory and psychophysiological exercise responses during wheelchair propulsion at selected velocities. Fifteen male paraplegics (27.0 ± 5.5 yrs) performed three discontinuous exercise tests (ACE = arm crank ergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, VO₂, V_E, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km-h¹. In contrast, at 8 km-h⁻¹ subjects demonstrated a 13% lower steady state VO₂ (p < .05) using the 10-in handrims, coincident with a 23% lower V_E Steady state HR during WERG at 8 km-h⁻¹ using the 10-in (124.4 ± 39 b.min⁻¹) or 16-in (130.6 ± 4.6 b.min⁻¹) handrims were not significantly different. There were also no significant differences between ACE or WERG conditions during maximal effort for VO₂ or V_E. However, HRpeak during ACE was 7% higher than HRpeak during WERG16 (183 ± 15 b.min⁻¹ vs. 171 ± 12 b.min⁻¹, p < .05), and whole blood HLa during ACE was also significantly higher (by 2.3-2.5 mmol; p < .05) compared to WERG. There were no significant differences for HR, performance time, or RPE between trials using different handrim diameters during the 1600-m event. In contrast, HLa was significantly lower using smaller handrims (9.9 mmol) compared with larger handrims (11.3 mmol), paralleling a similar difference in the laboratory. Although these data demonstrated few significant differences of physiologic responses between trials using different handrims, there was a tendency for a lower metabolic stress using the smaller handrims.

Key Words:

• wheelchair exercise
• cardiorespiratory response
• paraplegic
• handrims