DEVELOPMENT OF A METHOD FOR PREVENTING ORTHOSTATIC HYPOTENSION DURING PROLONGED STATIC STANDING

开发一种预防长时间静态站立期间直立性低血压的方法

• 批准号: 05680083
• 负责人: INAMURA Kinsaku
• 金额: $ 0.38万
• 依托单位: SHIZUOKA UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05680083/
• 关键词: Countermeasure; Orthostatic hypotension; Prolonged static standing; Muscle pumping; Cardiac output; Postural sway; 静脈還流

To develop a method for preventing orthostatic hypotension using voluntary muscle contraction, 30 healthy young males aged from 18 to 23 years were required to maintain upright standing for 30 min. Front-back sway of foot pressure center (postural sway) by a platform stabilometry, and cardiac parameters by an impedance plethysmography were measured during the experiments. Control condition was static standing with as little movement as possible. Experimental conditions were (A) static standing with repetitive voluntary muscle contractions in the lower abdomen at the timing of a backward shift in postural sway, (B) standing with the repetitive muscle contractions in the middle abdomen at the timing of a backward shift, (C) standing with the repetitive muscle contractions in the calf and lower abdomen at the timing of a forward shift, and (D) standing with the repetitive muscle contractions in the calf at the timing of a forward shift and the contractions in the abdominal muscles at the timing of a backward shift. Results of the cardiac parameters for 20 min in the experimental conditions were compared with the ones in control condition.In the condition (A), mean values of stroke volume in 43% of the subjects increased. The ones in 40% of the subjects increased in condition (B). The ones in 50% of the subjects increased in condition (C). The ones in the 62% of the subjects increased in condition (D). Increase ratio of stroke volume in these subjects in condition (D) was 10.1% . This increase was statistically significant (p<0.01). Increase ratio of cardiac output was 12.6%.These results may signify that the voluntary muscle contraction in condition (D) is regarded as the most effective method for enhancing the muscle pumping. We concluded that the voluntary muscle contraction in the calf and abdomen synchronized with postural sway is expected to be useful as a countermeasure to orthostatic hypotension or syncope in prolonged static standing in humans.

为了研究一种利用随意肌收缩预防体位性低血压的方法，我们要求30名年龄在18岁至23岁之间的健康年轻男性保持直立站立30分钟。在实验中，通过平台稳定仪测量足压中心的前后摆动（体位摆动），并通过阻抗容积描记仪测量心脏参数。控制条件是静止站立，尽量少运动。实验条件为：(A)静态站立，下腹部肌肉在姿势摇摆时向后移动时重复收缩；(B)站立，中腹部肌肉在向后移动时重复收缩；(C)站立，小腿和下腹部肌肉在向前移动时重复收缩。(D)站立时，小腿肌肉在向前移动时的重复收缩和腹部肌肉在向后移动时的收缩。将实验条件下20 min的心脏参数与对照组进行比较。在(A)条件下，43%的受试者的平均脑卒中容量增加。40%的受试者在条件(B)中增加了。50%的受试者在条件(C)中增加了。62%的被试在条件(D)上增加了。D组脑卒中容量增加率为10.1%。这一增加有统计学意义（p<0.01）。心输出量增加率为12.6%。这些结果可能表明，状态(D)的随意肌收缩被认为是增强肌肉泵送的最有效方法。我们的结论是，与姿势摇摆同步的小腿和腹部的随意肌收缩有望作为人类长时间静止站立时直立性低血压或晕厥的对策。