PHYSIOLOGICAL-RESPONSES DURING WHEELCHAIR RACING IN QUADRIPLEGICS ANDPARAPLEGICS

The purposes of this study were: (1) to compare the physiological resp onses during simulated wheelchair racing (SR) between male quadriplegi cs and paraplegics, (2) to test the validity of the SR against a track race (TR) and (3) to examine the relationship between the peak oxygen uptake (peak VO2) and wheeling velocity (WV) during the SR and TR. Se ven quadriplegics (C5-8 lesions) and six paraplegics (T5-L4 lesions) c ompleted (1) an incremental wheelchair velocity test, (2) a SR (1.6 km for quadriplegics and 3.2 km for paraplegics), and (3) an indoor TR o f the same distance. The subjects performed the incremental velocity t est and SR in their personal wheelchairs mounted on a roller system in terfaced with customized software programmed to provide velocity and d istance feedback. Physiological responses were monitored using an auto mated metabolic cart and electrocardiogram. Blood lactate concentratio n [La] was determined from finger prick samples. Peak VO2 and peak hea rt rate (peak HR) were significantly higher in the paraplegics compare d to quadriplegics: 1.90 +/- 0.54 vs 1.07 +/- 0.35 1/min, and 188 +/- 11 beats/min vs 117 +/- 12 beats/min respectively. The paraplegics exe rcised at significantly (p < 0.05) higher percentages of peak VO2 and peak HR during the SR compared to quadriplegics (95% vs 76% and 95% vs 86%, respectively). No significant relationships (p > 0.05) were obse rved between the peak VO2 and WV during the SR and TR in either group. Significant relationships (p < 0.05) were observed between the SR and TR for the race time, WV, HR, and [La] in both groups of subjects. Th ese results suggest: (1) that factors other than peak VO2 influence wh eelchair racing performance in quadriplegics and paraplegics, and (2) that wheelchair roller racing evaluated in the laboratory is a valid m easure of track racing performance in spinal cord injured subjects.