An investigation of cardiovascular fitness and its training for severely mentally and physically disabled persons

严重精神和身体残疾是指既患有严重精神发育迟滞又患有严重身体残疾的人。相当数量的残疾人长期卧床不起。下体负压(LBNP)可能是刺激心血管功能的可能方法之一。LBNP提供了一种降低压力的方法，通常施加在下半身，并模拟重力的影响。我们开发了下体负压装置，并调查了他们的心血管反应和使用下体负压方法进行训练的可能性。正如之前研究的那样，在下体负压期间，血液会聚集在四肢。此外，外周血管收缩是由压力感受器介导的反射激活的，减少了外周血流量。因此，收缩压不变，而舒张压升高。心率增加以补偿每搏量的减少。我们对正常受试者的结果证实，对下体负压的心血管反应与先前的报道一致。另一方面，在下体负压期间，残疾人的心脏和血管控制不足。也就是说，完全卧床不起的残疾人在下体负压期间的心率没有变化。在日常生活中经历被动坐姿的残疾人表现为心率增快，心率低于正常人。在下体负压分级过程中，两组残疾人的血压均呈递减趋势。重度残障人群的血压降幅大于坐位残障人群。这提示重度残疾人的中枢和外周循环系统功能严重低下或功能障碍。为了维持良好的机能和健康，即使通过被动的模拟体力工作，也有必要让他们参与心血管素质的训练。

Severely mentally and physically disabled persons are those who suffer from both severe mental retardation and severe physical disabilities. A considerable number of the disabled persons are bedridden for a prolonged period of time. Lower body negative pressure (LBNP) may be one of possible methods for stimulating the cardiovascular function. The LBNP provides a mean to apply reduced pressure usually to., lower body and simulates the effect of gravity. We developed the LBNP device and investigated their cardiovascular responses and possibility of training using the LBNP method. As previously investigated, the blood is pooled in lower extremities during the LBNP. Furthermore, peripheral vasoconstriction is activated by barorecepter-mediated reflex reduces peripheral blood flow. Consequently, the systolic pressure does not change and the diastolic pressure elevates. Heart rate increases to compensate decreasing stroke volume. Our results for the normal subjects confirmed that the cardiovascular response to the LBNP agreed well with the previous reports. On the other hand, inadequate control in heart and vasculature during the LBNP was observed for the disabled persons. That is, the heart rate for the disabled persons completely bedridden did not change during the LBNP. The disabled persons experiencing passively sitting posture in daily.living.showed elevated heart rate which was lower in comparison with the normal subjects. The blood pressures of both groups of the disabled persons decreased progressively during the graded LBNP. The depression of the blood pressure for the most severely disabled group was greater than that for the disabled persons with sitting posture. This suggested serious lower function or dysfunction in both central and peripheral circulatory system of the severely disabled persons. In order to sustain good function and health, it is necessary to involve them in training of cardiovascular fitness even by passively simulated physical work.