A COMPARISON OF THREE ARM ERGOMETRY PROTOCOLS IN INDIVIDUALS WITH PARAPLEGIA AND ABLE-BODIED CONTROLS 482

Abstract

Lower body exercise stress tests are used in able-bodied individuals to quantify cardiorespiratory function. To attain valid results, the modality of exercise utilized during the exercise stress test must closely match activities regularly performed by the individual. For this reason, Taylor et al. 1955 standardized exercise stress tests in an able-bodied population performing exercise on a treadmill. In the disabled population, particularly individuals with paraplegia, standardized exercise stress testing using arm ergometry has not been validated. The purpose of this study was to standardized arm crank ergometry exercise testing for a paraplegic and an able-bodied population. Males with paraplegia (T7 - T12) and able-bodied controls between the ages of 20 and 40 years were recruited. Subjects performed three maximal arm crank ergometry tests, 3 Watts/15 sec at 30 RPM (A), 6 Watts/30 sec at 60 RPM (B) and 12 Watts/min at 60 RPM (C). A metabolic cart (system 2900, SensorMedics Yorba Linda, CA) was employed for the measurement of all gas exchange values during the exercise tests. A repeated measures ANOVA was used to determine differences among the protocols, pre-exercise, at anaerobic threshold and at peak exercise, for oxygen consumption (VO2), heart rate (HR), O2 pulse (O2p), ventilation (VE) and work rate (WATTS). No significant differences were found for any variable pre-exercise or at anaerobic threshold. Peak exercise HR was not significantly different among the three test protocols. O2p at peak exercise was significantly lower for protocol A compared with protocols B and C (13.4 ± 4.3 vs 15.3 ± 3.7 and 15.9 ± 4.3 ml/bt, p<0.05, respectively). Peak VO2 was significantly lower for protocol A compared with protocols B and C (1.96 ±.74 vs 2.29±.63 and 2.36 ±.72 L/min, p<0.05, respectively). At peak exercise, absolute workload was also significantly lower for protocol A compared with protocols B and C (109.5 ± 32.6 vs 136.5 ± 36.1 and 132 ± 35.3 watts, p<0.05, respectively). In conclusion, the three arm ergometry exercise protocols elicited similar heart rate and ventilatory responses at peak exercise. The 12 watt/min and the 6 watt/30 sec protocols appear to be metabolically more efficient thus permitting greater physical work capacity compared with the 3 watt/15 sec protocol.