排序方式: 共有1条查询结果,搜索用时 0 毫秒
1
1.
Abdominal muscle fatigue after maximal ventilation in humans 总被引:4,自引:0,他引:4
Kyroussis Dimitris; Mills Gary H.; Polkey Michael I.; Hamnegard Carl-Hugo; Koulouris Nicholaos; Green Malcolm; Moxham John 《Journal of applied physiology》1996,81(4):1477-1483
Kyroussis, Dimitris, Gary H. Mills, Michael I. Polkey,Carl-Hugo Hamnegard, Nicholaos Koulouris, Malcolm Green, and John Moxham. Abdominal muscle fatigue after maximal ventilation inhumans. J. Appl. Physiol. 81(4):1477-1483, 1996.Abdominal muscles are the principal muscles ofactive expiration. To investigate the possibility of abdominal musclelow-frequency fatigue after maximal ventilation in humans, westimulated the nerve roots supplying the abdominal muscles. We used amagnetic stimulator (Magstim 200) powering a 90-mm circular coil andstudied six normal subjects. To assess the optimum level of stimulationand posture, we stimulated at each intervertebral level betweenT7 andL1 in the prone, supine, andseated positions. At T10, we usedincreasing power outputs to assess the pressure-power relationship.Care was taken to avoid muscle potentiation. Twitch gastric pressure(Pga) was recorded with a balloon-tipped catheter. Mean (±SD)baseline twitch Pga measured with the subjects in the prone position atT10 was 23.5 ± 5.4 cmH2O. Within-occasion mean twitchPga coefficient of variation was 4.6 ± 1.1%. Twitch Pga wasmeasured with the subjects in the prone position with stimulation overT10 before and after 2 min ofmaximal isocapnic ventilation (MIV). Twenty minutes after MIV, meantwitch Pga fell by 17 ± 9.1%(P = 0.03) and remained low 90 minafter MIV. We conclude that after maximal ventilation in humans thereis a reduction of twitch Pga and, therefore, of low-frequency fatiguein abdominal muscles. 相似文献
1