Generating waist area-dependent ground reaction forces for long-duration spaceflight.
Generating waist area-dependent ground reaction forces for long-duration spaceflight.
复制标题
产生与腰部区域相关的地面反作用力，以进行长时间的太空飞行。
DOI：
10.1016/j.jbiomech.2021.110272
复制
发表时间：
2021
影响因子：
2.4
通讯作者：
Hargens,AlanR
中科院分区：
文献类型：
--
作者：
Ashari,Neeki;Kong,Mitchell;Poudel,Alisha;Friend,James;Hargens,AlanR
长时间的微重力暴露会大大削弱宇航员的骨骼和肌肉。这对宇航员来说是一个关键的生物力学问题，因为他们可能更容易骨折。为了解决这个问题，下体负压（LBNP）是一个产生人造重力的概念，可以帮助在长期太空飞行中加强骨骼和肌肉。负压（定义为低于环境压力）施加在包围身体下半部的腔室内。通过增加负压，在受试者的脚下产生更多的地面反作用力（GRF）。我们假设增加受试者腰部的横截面积（CSA）将在受试者的脚下产生更大的GRF。六名健康受试者自愿参加两种不同的实验条件：1）他们的腰部的原始CSA和2）他们的腰部的较大CSA。在这两种情况下，受试者都以仰卧位（模拟微重力）沿着悬浮，脚下放着体重秤。负压范围为0至50 mmHg，以5 mmHg的增量增加。在-50 mmHg下，原始CSA产生了正常体重的1.18 ± 0.31（平均值± SD）。受试者使用其原始腰部CSA在−45 mmHg下产生约一个体重。在-50 mmHg下，较大的CSA产生的体重为正常体重的1.46 ± 0.31。受试者使用较大的腰部CSA在-35 mmHg下产生约一个体重。这些数据支持我们的假设。这种新技术可以减少对心血管系统的压力，并为航天器中的运动节省能量。
Prolonged microgravity exposure greatly weakens the bones and muscles of astronauts. This is a critical biomechanical issue for astronauts as they may be more prone to bone fractures. To combat this issue, lower body negative pressure (LBNP) is a concept that generates artificial gravitational forces that may help strengthen bones and muscles during long-term spaceflight. Negative pressure, defined as below ambient pressure, is applied within a chamber that encompasses the lower half of the body. By increasing the negative pressure, more ground reaction forces (GRFs) are generated beneath the subject’s feet. We hypothesize that increasing the cross-sectional area (CSA) of the subject’s waist will generate greater GRFs beneath the subject’s feet. Six healthy subjects volunteered to participate under two different experimental conditions: 1) original CSA of their waist and 2) larger CSA of their waist. In both conditions the subjects were suspended in a supine position (simulated microgravity) along with a weight scale beneath their feet. Negative pressures ranged from zero to 50 mmHg, increasing in increments of 5 mmHg. At −50 mmHg, original CSAs generated 1.18 ± 0.31 (mean ± SD) of their normal bodyweight. Subjects generated about one bodyweight at −45 mmHg using their original waist CSA. At −50 mmHg, larger CSAs generated 1.46 ± 0.31 of their normal bodyweight. Subjects generated about one bodyweight at −35 mmHg using their larger waist CSA. These data support our hypothesis. This novel technique may apply less stress to the cardiovascular system and conserve power for exercise in the spacecraft.