CARDIORESPIRATORY AND PERCEPTUAL RESPONSES TO ARM CRANK AND WHEELCHAIR EXERCISE USING VARIOUS HANDRIMS IN MALE PARAPLEGICS

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 ± 53 yrs) performed three discontinuous exercise tests (ACE = arm crankergometer; WERG = wheelchair roller ergometer) and two 1600-m performance-based track trials (TRACK) under simulated race conditions. There were no significant differences in HR, V02, V£, HLa, or category-ratio ratings of perceived exertion (RPE) using different handrims during wheelchair propulsion at 4 km/h-1. In contrast, at 8 km/h-1 subjects demonstrated a 13% lower steady state V02 (p <.05) using the 10-in handrims, coincident with a 23% lower V£. Steady state HR during WERG at 8 km-h'1 using the 10-in (124.4 ±3.9 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 V02 or V£. 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 23-23 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 (113 mmol), paralleling a similar difference in the laboratory. Although these data demonstrated few significant differences ofphysiologic responses between trials using different handrims, there was a tendency for a lower metabolic stress using the smaller handrims. © 1990 Taylor and Francis Group, LLC.