Hill A R, Kaiser D L, Rochester D F
J Appl Physiol Respir Environ Exerc Physiol. 1984 May;56(5):1294-301. doi: 10.1152/jappl.1984.56.5.1294.
To assess the effects of lung volume and chest wall configuration on electromechanical coupling of the abdominal muscles, we examined the relationship between abdominal muscle pressure ( Pmus ) and electrical activity ( EMGab ) in eight normal subjects during expiratory efforts at lung volumes ranging from functional residual capacity (FRC) to FRC + 2.0 liters. At and above FRC, increases of lung volume did not significantly alter either the Pmus - EMGab relationship or abdominal surface linear dimensions, although expiratory efforts displaced the abdomen inward from its relaxed position. We attribute the constancy of delta Pmus /delta EMG above FRC to the negligible effects of increasing lung volume on abdominal configuration and muscle length. Expiratory efforts performed at lung volumes below FRC resulted in a wider range of abdominal indrawing . Under these conditions the EMGab required to augment Pmus by 30-40 cmH2O increased as the abdomen was displaced inward. This decrease of delta Pmus /delta EMGab appears to reflect muscle shortening, flattening of the abdominal wall, and possibly deformation of the rib cage.
为评估肺容积和胸壁形态对腹肌机电耦联的影响，我们在8名正常受试者从功能残气量（FRC）至FRC + 2.0升的肺容积下进行呼气动作时，检测了腹肌压力（Pmus）与电活动（EMGab）之间的关系。在FRC及高于FRC时，尽管呼气动作使腹部从其松弛位置向内移位，但肺容积增加并未显著改变Pmus - EMGab关系或腹部表面线性尺寸。我们将FRC以上时ΔPmus /ΔEMG的恒定归因于肺容积增加对腹部形态和肌肉长度的影响可忽略不计。在低于FRC的肺容积下进行呼气动作会导致更广泛的腹部内陷。在这些情况下，随着腹部向内移位，使Pmus增加30 - 40 cmH2O所需的EMGab增加。ΔPmus /ΔEMGab的这种降低似乎反映了肌肉缩短、腹壁变平以及可能的胸廓变形。
