Effects of 30 d-6°Head-down Bed Rest on Lumbar Spine and Lumbar Paraspinal Muscles
FENG Jin-sheng
LI Yong-zhi
GUO Li-guo
SHI Hong-zhi
LI Yi-xing
JIN Zhen
WANG Jian
Abstract：Objective To study the changes of entire lumbar spinal height,the lordotic angle,the midsagittal area between adjacent lumbar vertebral bodies and the cross-sectional area of lumbar paraspinal muscles following 30 d-6°head-down bed rest (HDBR.Methods A 30 d-6°HDBR experiment was proposed to simulate weightlessness effects.Fourteen healthy male subjects volunteered to participate in the experiment.All subjects underwent magnetic resonance imaging (MRI)test in supine psoas-relaxed position before and after HDBR.Midsagittal views were used to measure the entire lumbar spinal height,the midsagittal area between adjacent lumbar vertebral bodies and lordotic angle.Axial MR image at the level of the L4-L5 disc was used to determine cross-sectional area of lumbar paraspinal muscles.Results After 30 d-6°HDBR,the entire lumbar spinal height of subjects was higher and the midsagittal areas of subjects were larger than those measured before HDBR (P < 0.01).The cross-sectional area of lumbar paraspinal muscles reduced significantly (P < 0.01).The lordotic angle of subjects did not change significantly.Conclusion Thirty days of HDBR at-6°can affect lumbar spinal stability and function and then result in the changes in lumbar spinal biomechanics.
Keywords：head-down bed restlumbar spinal heightlumbar paraspinal muscleslow back pain
Publication Date：2011-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)