Wilson T A, Legrand A, Gevenois P A, De Troyer A
Laboratory of Cardiorespiratory Physiology, Brussels School of Medicine, 1070 Brussels, Chest Service and Department of Radiology, Erasme University Hospital, 1070 Brussels, Belgium.
J Physiol. 2001 Jan 15;530(Pt 2):319-30. doi: 10.1111/j.1469-7793.2001.0319l.x.
The current conventional view of intercostal muscle actions is based on the theory of Hamberger (1749) and maintains that as a result of the orientation of the muscle fibres, the external intercostals have an inspiratory action on the lung and the internal interosseous intercostals have an expiratory action. Recent studies in dogs, however, have shown that this notion is only approximate. In the present studies, the respiratory actions of the human external and internal intercostal muscles were evaluated by applying the Maxwell reciprocity theorem. Thus the orientation of the muscle fibres relative to the ribs and the masses of the muscles were first assessed in cadavers. Five healthy individuals were then placed in a computed tomographic scanner to determine the geometry of the ribs and their precise transformation during passive inflation to total lung capacity. The fractional changes in length of lines with the orientation of the muscle fibres were then computed to obtain the mechanical advantages of the muscles. These values were finally multiplied by muscle mass and maximum active stress (3.0 kg cm-2) to evaluate the potential effects of the muscles on the lung. The external intercostal in the dorsal half of the second interspace was found to have a large inspiratory effect. However, this effect decreases rapidly in the caudal direction, in particular in the ventral portion of the ribcage. As a result, it is reversed into an expiratory effect in the ventral half of the sixth and eighth interspaces. The internal intercostals in the ventral half of the sixth and eighth interspaces have a large expiratory effect, but this effect decreases dorsally and cranially. The total pressure generated by all the external intercostals during a maximum contraction would be -15 cmH2O, and that generated by all the internal interosseous intercostals would be +40 cmH2O. These pressure changes are substantially greater than those induced by the parasternal intercostal and triangularis sterni muscles, respectively.
目前关于肋间肌作用的传统观点基于汉伯格（1749年）的理论，该理论认为，由于肌纤维的取向，肋间外肌对肺有吸气作用，肋间内肌有呼气作用。然而，最近对狗的研究表明，这种观点只是近似正确的。在本研究中，通过应用麦克斯韦互易定理评估了人类肋间外肌和肋间内肌的呼吸作用。因此，首先在尸体上评估肌纤维相对于肋骨的取向以及肌肉的质量。然后将五名健康个体置于计算机断层扫描仪中，以确定肋骨的几何形状及其在被动充气至肺总量时的精确变化。接着计算与肌纤维取向一致的线条长度的分数变化，以获得肌肉的机械优势。最后将这些值乘以肌肉质量和最大主动应力（3.0 kg/cm²），以评估肌肉对肺的潜在影响。发现第二肋间间隙背侧半部分的肋间外肌有较大的吸气作用。然而，这种作用在尾侧方向迅速减弱，特别是在胸廓的腹侧部分。结果，在第六和第八肋间间隙的腹侧半部分，其作用转变为呼气作用。第六和第八肋间间隙腹侧半部分的肋间内肌有较大的呼气作用，但这种作用在背侧和头侧方向减弱。所有肋间外肌在最大收缩时产生的总压力为-15 cmH₂O，所有肋间内肌产生的总压力为+40 cmH₂O。这些压力变化分别明显大于胸骨旁肋间肌和胸骨三角肌引起的压力变化。
