Andersen T Bull, Essendrop M, Schibye B
Department of Sport Science, University of Aarhus, 8200 Aarhus N, Denmark.
Eur J Appl Physiol. 2004 Apr;91(4):488-92. doi: 10.1007/s00421-004-1040-6. Epub 2004 Feb 11.
Sudden loading of the spine is not only considered a risk factor for the development of low-back pain but also enables an evaluation of the stability of the spine when conducted under laboratory conditions. In the present study the upper spine was pulled in the anterior direction and the stiffness as well as activity in the erector spinae muscle was measured with different pre-tension in the erector spinae. The results showed that increased activity in the erector spinae prior to loading led to increased stiffness (stiffness coefficients from 297 Nm rad(-1) to 438 Nm rad(-1)) and a decrease in the extra neural signal input to the muscles to maintain the stability. It is therefore clear that increased tension in the erector spinae muscle will create a larger stability of the spine to anterior perturbations. However, contracting the muscles around the spine increases the load on the spinal structures. In 34% of the experiments a silent period in the electromyographic signal was present after loading in the period when the torso was moving in the anterior direction. This phenomenon is discussed.
脊柱的突然加载不仅被认为是下背痛发展的一个风险因素，而且在实验室条件下进行时，还能对脊柱的稳定性进行评估。在本研究中，上脊柱向前方牵拉，在竖脊肌不同预张力下测量其刚度以及竖脊肌的活动。结果表明，加载前竖脊肌活动增加导致刚度增加（刚度系数从297 Nm rad⁻¹增加到438 Nm rad⁻¹），并且维持稳定性的肌肉额外神经信号输入减少。因此很明显，竖脊肌张力增加会使脊柱对前方扰动具有更大的稳定性。然而，脊柱周围肌肉的收缩会增加脊柱结构上的负荷。在34%的实验中，在躯干向前移动期间加载后，肌电信号出现了静息期。对这一现象进行了讨论。
