Styf J R, Ballard R E, Fechner K, Watenpaugh D E, Kahan N J, Hargens A R
Gravitational Research Branch, NASA Ames Research Center, Moffett Field, CA 94035-1000, USA.
Aviat Space Environ Med. 1997 Jan;68(1):24-9.
Spinal lengthening and back pain are commonly experienced by astronauts exposed to microgravity.
To develop a ground-based simulation for spinal adaptation to microgravity, we investigated height increase, neuromuscular function and back pain in 6 subjects all of whom underwent two forms of bed rest for 3 d. One form consisted of 6 degrees of head-down tilt (HDT) with balanced traction, while the other was horizontal bed rest (HBR). Subjects had a 2-week recovery period in between the studies.
Total body and spinal length increased significantly more and the subjects had significantly more back pain during HDT with balanced traction compared to HBR. The distance between the lower endplate of L4 and upper endplate of S1, as measured by ultrasonography, increased significantly in both treatments to the same degree. Intramuscular pressures in the erector spinae muscles and ankle torque measurements during plantarflexion and dorsiflexion did not change significantly during either treatment.
Compared to HBR, HDT with balanced traction may be a better method to simulate changes of total body and spinal lengths, as well as back pain seen in microgravity.
暴露于微重力环境下的宇航员通常会经历脊柱拉长和背痛。
为了开发一种基于地面的模拟脊柱适应微重力的方法，我们对6名受试者进行了研究，他们均接受了两种形式的卧床休息，为期3天。一种形式是6度头低位倾斜（HDT）并伴有平衡牵引，另一种是水平卧床休息（HBR）。受试者在两次研究之间有2周的恢复期。
与HBR相比，在进行平衡牵引的HDT期间，全身和脊柱长度的增加更为显著，受试者的背痛也更为明显。通过超声测量，两种治疗中L4下端板与S1上端板之间的距离均显著增加，且增加程度相同。在两种治疗过程中，竖脊肌的肌内压力以及跖屈和背屈时的踝关节扭矩测量值均无显著变化。
与HBR相比，平衡牵引的HDT可能是一种更好的方法，用于模拟微重力环境下所见的全身和脊柱长度变化以及背痛。
