Holguin Nilsson, Muir Jesse, Rubin Clinton, Judex Stefan
Department of Biomedical Engineering, State University of New York at Stony Brook, Psychology A, 3rd Floor, Stony Brook, NY 11794-2580, USA.
Spine J. 2009 Jun;9(6):470-7. doi: 10.1016/j.spinee.2009.02.009. Epub 2009 Apr 8.
Loss of functional weightbearing during spaceflight or extended bed rest (BR) causes swelling of the lumbar intervertebral discs (IVDs), elongates the spine, and increases the incidence of low back pain (LBP). Effective interventions for the negative effects of unloading are critical but not yet available.
To test the hypothesis that high-frequency, low-magnitude mechanical signals (LMMS) can attenuate the detrimental morphologic changes in the lumbar IVDs.
STUDY DESIGN/SETTING: Volunteers were subjected to 90d of BR and 7d of reambulation. While retaining this supine position, 18 random subjects received LMMS (30Hz) for 10min/d, at peak-to-peak acceleration magnitudes of either 0.3g (n=12) or 0.5g (n=6). The remaining subjects served as controls (CTRs).
Eighteen males and 11 female (33+/-7y) healthy subjects of astronaut age (35+/-7y, 18 males, 11 females) and without a history of back pain participated in this study.
A combination of magnetic resonance imaging and computed tomography scans of the lumbar spine of all subjects were taken at baseline, 60d, 90d, and 7d post-BR. Back pain was self-reported.
IVD morphology, spine length, and back pain were compared between CTR and LMMS subjects.
Compared with untreated CTRs, LMMS attenuated mean IVD swelling by 41% (p<.05) at 60d and 30% (p<.05) at 90d. After 7 days of reambulation, disc volume of the CTR group was still 8% (p<.01) greater than at baseline, whereas that for the LMMS group returned the disc volume to baseline levels. In contrast to BR alone, LMMS also retained disc convexity at all time points and reduced the incidence of LBP by 46% (p<.05).
These data indicate that short daily bouts of LMMS can mitigate the detrimental changes in disc morphology, which arise during nonweightbearing, and provides preliminary support for a novel means of addressing spinal deterioration both on earth and in space.
太空飞行或长期卧床休息（BR）期间功能性负重的丧失会导致腰椎间盘（IVD）肿胀、脊柱伸长，并增加腰痛（LBP）的发生率。针对卸载负面影响的有效干预措施至关重要，但目前尚未有可用的措施。
检验高频、低强度机械信号（LMMS）可减轻腰椎间盘有害形态学变化这一假设。
研究设计/设置：志愿者接受90天的卧床休息和7天的恢复行走。在保持仰卧位的同时，18名随机受试者每天接受10分钟的LMMS（30Hz），峰峰值加速度幅度为0.3g（n = 12）或0.5g（n = 6）。其余受试者作为对照组（CTR）。
18名男性和11名女性（33±7岁），年龄符合宇航员标准（35±7岁，18名男性，11名女性）且无背痛病史的健康受试者参与了本研究。
在基线、卧床休息60天、90天以及卧床休息后7天，对所有受试者的腰椎进行磁共振成像和计算机断层扫描。背痛通过自我报告。
比较对照组和接受LMMS受试者的椎间盘形态、脊柱长度和背痛情况。
与未治疗的对照组相比，LMMS在60天时使平均椎间盘肿胀减轻41%（p<0.05），在90天时减轻30%（p<0.05）。恢复行走7天后，对照组的椎间盘体积仍比基线时大8%（p<0.01），而LMMS组的椎间盘体积恢复到基线水平。与单独卧床休息相比，LMMS在所有时间点也保持了椎间盘的凸度，并使腰痛发生率降低了46%（p<0.05）。
这些数据表明，每天短时间的LMMS可减轻非负重期间出现的椎间盘形态的有害变化，并为解决地球上和太空中脊柱退化的新方法提供了初步支持。
