Swanenburg Jaap, Langenfeld Anke, Easthope Christopher A, Meier Michael L, Ullrich Oliver, Schweinhardt Petra
Integrative Spinal Research ISR, Department of Chiropractic Medicine, Balgrist University Hospital, Zurich, Switzerland.
Cereneo Center for Interdisciplinary Research, Vitznau, Switzerland.
Front Physiol. 2020 Sep 2;11:562557. doi: 10.3389/fphys.2020.562557. eCollection 2020.
The objective of this study was to determine the response of the lumbar spinal motor control in different gravitational conditions. This was accomplished by measuring indicators of lumbar motor control, specifically lumbar spinal stiffness, activity of lumbar extensor and flexor muscles and lumbar curvature, in hypergravity and microgravity during parabolic flights. Three female and five male subjects participated in this study. The mean age was 35.5 years (standard deviation: 8.5 years). Spinal stiffness of the L3 vertebra was measured using impulse response; activity of the erector spinae, multifidi, transversus abdominis, and psoas muscles was recorded using surface electromyography; and lumbar curvature was measured using distance sensors mounted on the back-plate of a full-body harness. An effect of gravity condition on spinal stiffness, activity of all muscles assessed and lumbar curvature ('s < 0.007) was observed (Friedman tests). analysis showed a significant reduction in stiffness during hypergravity ( < 0.001) and an increase in stiffness during microgravity ( < 0.001). Activity in all muscles significantly increased during hypergravity ('s < 0.001). During microgravity, the multifidi ( < 0.002) and transversus abdominis ( < 0.001) increased significantly in muscle activity while no significant difference was found for the psoas ( = 0.850) and erector spinae muscles ( = 0.813). Lumbar curvature flattened in hypergravity as well as microgravity, albeit in different ways: during hypergravity, the distance to the skin decreased for the upper ( = 0.016) and the lower sensor ( = 0.036). During microgravity, the upper sensor showed a significant increase ( = 0.016), and the lower showed a decrease ( = 0.005) in distance. This study emphasizes the role of spinal motor control adaptations in changing gravity conditions. Both hypergravity and microgravity lead to changes in spinal motor control. The decrease in spinal stiffness during hypergravity is interpreted as a shift of the axial load from the spine to the pelvis and thoracic cage. In microgravity, activity of the multifidi and of the psoas muscles seems to ensure the integrity of the spine. Swiss (BASEC-NR: 2018-00051)/French "EST-III" (Nr-ID-RCB: 2018-A011294-51/Nr-CPP: 18.06.09).
本研究的目的是确定腰椎脊髓运动控制在不同重力条件下的反应。这是通过在抛物线飞行的超重和微重力期间测量腰椎运动控制指标来实现的，具体包括腰椎脊髓刚度、腰伸肌和屈肌的活动以及腰椎曲度。三名女性和五名男性受试者参与了本研究。平均年龄为35.5岁（标准差：8.5岁）。使用脉冲响应测量L3椎体的脊髓刚度；使用表面肌电图记录竖脊肌、多裂肌、腹横肌和腰大肌的活动；使用安装在全身安全带背板上的距离传感器测量腰椎曲度。观察到重力条件对脊髓刚度、所有评估肌肉的活动和腰椎曲度有影响（P < 0.007）（Friedman检验）。分析表明，超重期间刚度显著降低（P < 0.001），微重力期间刚度增加（P < 0.001）。超重期间所有肌肉的活动均显著增加（P < 0.001）。在微重力期间，多裂肌（P < 0.002）和腹横肌（P < 0.001）的肌肉活动显著增加，而腰大肌（P = 0.850）和竖脊肌（P = 0.813）未发现显著差异。超重和微重力期间腰椎曲度均变平，尽管方式不同：超重期间，上传感器（P = 0.016）和下传感器（P = 0.036）到皮肤的距离减小。在微重力期间，上传感器显示距离显著增加（P = 0.016），下传感器显示距离减小（P = 0.005）。本研究强调了脊髓运动控制适应在重力条件变化中的作用。超重和微重力都会导致脊髓运动控制的变化。超重期间脊髓刚度的降低被解释为轴向负荷从脊柱转移到骨盆和胸廓。在微重力环境下，多裂肌和腰大肌的活动似乎确保了脊柱的完整性。瑞士（BASEC-NR：2018-00051）/法国“EST-III”（Nr-ID-RCB：2018-A011294-51/Nr-CPP：18.06.09）。
