McKenzie D K, Gandevia S C
Am Rev Respir Dis. 1986 Nov;134(5):999-1004. doi: 10.1164/arrd.1986.134.5.999.
To determine whether asthma is associated with changes in the maximal performance of skeletal muscles, 20 asthmatic and 20 control subjects performed series of 12 maximal static contractions of 15 s duration separated by rest intervals of 15 s (duty cycle, 50%) with the inspiratory and expiratory muscles and a control limb muscle. Muscle strength of the asthmatics did not differ significantly from that of the control subjects. During the series of contractions the maximal and average sustained inspiratory pressures did not decline in control or asthmatic subjects, whereas for both groups of subjects, the expiratory pressures declined about 15%, and elbow force declined about 30%. However, endurance of the expiratory muscles was significantly enhanced in the male asthmatic subjects, who were more severely obstructed than the female subjects. When tested with a duty cycle of 67%, the inspiratory muscles of asthmatic subjects fatigued significantly less than those of control subjects.
为了确定哮喘是否与骨骼肌最大运动能力的变化有关，20名哮喘患者和20名对照受试者对吸气肌、呼气肌和一个对照肢体肌肉进行了一系列12次持续15秒的最大静态收缩，每次收缩间隔15秒的休息时间（占空比50%）。哮喘患者的肌肉力量与对照受试者相比无显著差异。在一系列收缩过程中，对照受试者和哮喘患者的最大和平均持续吸气压力均未下降，而两组受试者的呼气压力均下降约15%，肘部力量下降约30%。然而，男性哮喘患者的呼气肌耐力显著增强，他们的气道阻塞比女性患者更严重。当以67%的占空比进行测试时，哮喘患者的吸气肌疲劳程度明显低于对照受试者。
