Petrofsky J S, Stacy R
Petrofsky Center for Rehabilitation and Research, Irvine, California.
Eur J Appl Physiol Occup Physiol. 1992;64(6):487-92. doi: 10.1007/BF00843755.
Endurance for dynamic exercise, cardiac output, blood pressure, heart rate, ventilation, and oxygen consumption was measured in eight individuals with paraplegia at the end of 4-min bouts of exercise on a friction braked cycle ergometer. Movement of the subjects' legs was induced by electrically stimulating the quadriceps, gluteus maximus and hamstring muscles with a computer-controlled biphasic square--wave current at a frequency of 30 Hz. The friction braked cycle ergometer was pedalled at work rates which varied between 0 and 40 W. Measurements were repeated after 3 and 6 months to assess the affect of training. After 3 months of training it was found that endurance increased from 8 min at a work rate of 0 W to 30 min at a work rate of 40 W. Compared to the cardiovascular responses in non-paralyzed subjects, computerized cycle ergometry was found to be associated with higher relative stresses for a given level of absolute work. Mean blood pressure, for example, increased by over 30% during maximal work in individuals with paralysis compared to the typical response obtained for able-bodied subjects. Analysis of the data showed that instead of the 20-30% metabolic efficiency commonly reported for cycle ergometry, the calculated metabolic efficiency during computer-controlled cycle ergometry was only 3.6%.
在摩擦制动式自行车测力计上对8名截瘫患者进行4分钟运动后，测量其动态运动耐力、心输出量、血压、心率、通气量和耗氧量。通过计算机控制的双相方波电流以30赫兹的频率电刺激股四头肌、臀大肌和腘绳肌，诱发受试者腿部运动。在0至40瓦的工作强度下蹬踏摩擦制动式自行车测力计。在3个月和6个月后重复测量，以评估训练效果。经过3个月的训练，发现耐力从工作强度0瓦时的8分钟增加到工作强度40瓦时的30分钟。与非瘫痪受试者的心血管反应相比，发现对于给定的绝对工作量水平，计算机化自行车测力计与更高的相对压力相关。例如，与健全受试者的典型反应相比，瘫痪个体在最大工作量时平均血压升高超过30%。数据分析表明，计算机控制的自行车测力计计算出的代谢效率不是通常报道的自行车测力计的20%-30%，而仅为3.6%。
