Smith J C, Mead J
J Appl Physiol (1985). 1986 Mar;60(3):928-34. doi: 10.1152/jappl.1986.60.3.928.
A three degree of freedom description of movement of the human chest wall is presented. In addition to the standard variables representing surface displacements of the rib cage and abdominal wall in transverse planes, the description includes a variable representing axial displacements of the chest wall associated with postural movements of the spine and pelvis. A simple technique was developed for quantifying the axial displacements using a single measurement by magnetometry of changes in the distance between a point on the anterior surface of the rib cage near the xiphisternum and a point on the abdominal surface near the pubic symphysis. It was found that axial displacements produced by either flexion-extension of the spine or rotation of the pelvis in the standing postures can be treated as a single degree of freedom. The chest wall displacements induced over the range of axial displacement examined were as large as those normally accompanying a change in lung volume on the order of 30-50% of the vital capacity. It is concluded, however, that although this additional degree of freedom can cause large chest wall displacements, it probably cannot independently change lung volume. This implies that the system is constrained so that there are only a limited number of independent modes of chest wall movement that are capable of producing significant changes in lung volume. It also suggests that the system is constructed so that lung volume can be relatively independent of certain postural distortions of the chest wall.
本文提出了一种对人体胸壁运动的三自由度描述。除了表示胸廓和腹壁在横向平面上表面位移的标准变量外，该描述还包括一个表示与脊柱和骨盆姿势运动相关的胸壁轴向位移的变量。开发了一种简单的技术，通过使用磁力测量法单次测量胸廓前表面靠近剑突的一点与腹表面靠近耻骨联合的一点之间距离的变化来量化轴向位移。研究发现，在站立姿势下，脊柱屈伸或骨盆旋转产生的轴向位移可视为一个自由度。在所检查的轴向位移范围内引起的胸壁位移与肺活量变化约30%-50%时通常伴随的胸壁位移一样大。然而，可以得出结论，尽管这个额外的自由度会导致较大的胸壁位移，但它可能无法独立改变肺容积。这意味着该系统受到限制，以至于只有有限数量的能够显著改变肺容积的胸壁独立运动模式。这也表明该系统的构造使得肺容积可以相对独立于胸壁的某些姿势变形。
