Hodges P W, Gandevia S C
Prince of Wales Medical Research Institute, University of New South Wales, Sydney, New South Wales 2031, Australia.
J Appl Physiol (1985). 2000 Sep;89(3):967-76. doi: 10.1152/jappl.2000.89.3.967.
In humans, when the stability of the trunk is challenged in a controlled manner by repetitive movement of a limb, activity of the diaphragm becomes tonic but is also modulated at the frequency of limb movement. In addition, the tonic activity is modulated by respiration. This study investigated the mechanical output of these components of diaphragm activity. Recordings were made of costal diaphragm, abdominal, and erector spinae muscle electromyographic activity; intra-abdominal, intrathoracic, and transdiaphragmatic pressures; and motion of the rib cage, abdomen, and arm. During limb movement the diaphragm and transversus abdominis were tonically active with added phasic modulation at the frequencies of both respiration and limb movement. Activity of the other trunk muscles was not modulated by respiration. Intra-abdominal pressure was increased during the period of limb movement in proportion to the reactive forces from the movement. These results show that coactivation of the diaphragm and abdominal muscles causes a sustained increase in intra-abdominal pressure, whereas inspiration and expiration are controlled by opposing activity of the diaphragm and abdominal muscles to vary the shape of the pressurized abdominal cavity.
在人类中，当肢体的重复性运动以可控方式挑战躯干的稳定性时，膈肌的活动会变为强直性，但也会以肢体运动的频率进行调节。此外，强直性活动会受到呼吸的调节。本研究调查了膈肌活动这些组成部分的机械输出。记录了肋部膈肌、腹部和竖脊肌的肌电图活动；腹内压、胸内压和跨膈肌压力；以及胸廓、腹部和手臂的运动。在肢体运动期间，膈肌和腹横肌呈强直性活动，并在呼吸和肢体运动的频率上叠加有相位调制。其他躯干肌肉的活动不受呼吸调节。在肢体运动期间，腹内压随着运动的反作用力成比例增加。这些结果表明，膈肌和腹部肌肉的共同激活会导致腹内压持续升高，而吸气和呼气则由膈肌和腹部肌肉的相反活动控制，以改变加压腹腔的形状。
