Somatosensory feedback from the limbs exerts inhibitory influences on central neural drive during whole body endurance exercise
Somatosensory feedback from the limbs exerts inhibitory influences on central neural drive during whole body endurance exercise
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DOI：
10.1152/japplphysiol.90456.2008
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发表时间：
2008-12-01
影响因子：
3.3
通讯作者：
Dempsey, Jerome A.
中科院分区：
文献类型：
--
作者：
Amann, Markus;Proctor, Lester T.;Dempsey, Jerome A.
Amann M，普罗克特LT，Sebranek JJ，Eldridge MW，Pegelow DF，Dempsey JA.在全身耐力运动中，肢体的躯体感觉反馈对中枢神经驱动产生抑制作用。J Appl Physiol 105：1714-1724，2008.首次发表于2008年9月11日; doi：10.1152/japplphysiol.90456.2008。- 我们调查是否从收缩肢体肌肉的体感反馈施加抑制的影响，在闭环自行车运动中，受试者自愿决定他的第二次由第二中央电机驱动器的中央命令的确定。8名训练有素的自行车运动员进行了两次5公里的时间试验，没有（5 K（对照））或腰硬膜外麻醉（5 K（Epi）; 24 ml的0.5%利多卡因，椎间隙L3-L4）。使用叠加抽搐技术在休息时确定随意四头肌肌肉激活百分比。硬膜外利多卡因使试验前最大随意股四头肌力量（553 +/- 45 N）降低22 +/-3%。通过硬膜外利多卡因，自主股四头肌激活百分比也从97 +/- 1%降至81 +/- 3%，并且在5 KEpi后没有变化，表明在整个试验期间存在持续水平的神经损伤。在整个比赛中，功率输出降低了9 +/- 2%（P < 0.05）。我们发现硬膜外利多卡因的三种显著作用支持了运动肢体的体感反馈在整个高强度闭环自行车运动中作为中央命令的决定因素的实质性作用：1）显著增加股外侧肌的相对整合EMG; 2）尽管可用于激活的快缩肌纤维数量减少，但踏板力相似; 3）与减少的二氧化碳产生和心率不成比例地增加通气，与功率输出和氧气消耗不成比例地增加血压。这些研究结果表明，在高强度闭环耐力运动过程中，有意识和/或潜意识地确定中央电机驱动的大小，从收缩运动肌肉的体感反馈的抑制作用。
Amann M, Proctor LT, Sebranek JJ, Eldridge MW, Pegelow DF, Dempsey JA. Somatosensory feedback from the limbs exerts inhibitory influences on central neural drive during whole body endurance exercise. J Appl Physiol 105: 1714-1724, 2008. First published September 11, 2008; doi: 10.1152/japplphysiol.90456.2008. - We investigated whether somatosensory feedback from contracting limb muscles exerts an inhibitory influence on the determination of central command during closed-loop cycling exercise in which the subject voluntarily determines his second-by-second central motor drive. Eight trained cyclists performed two 5-km time trials either without (5K(Ctrl)) or with lumbar epidural anesthesia (5K(Epi); 24 ml of 0.5% lidocaine, vertebral interspace L3-L4). Percent voluntary quadriceps muscle activation was determined at rest using a superimposed twitch technique. Epidural lidocaine reduced pretime trial maximal voluntary quadriceps strength (553 +/- 45 N) by 22 +/- 3%. Percent voluntary quadriceps activation was also reduced from 97 +/- 1% to 81 +/- 3% via epidural lidocaine, and this was unchanged following the 5KEpi, indicating the presence of a sustained level of neural impairment throughout the trial. Power output was reduced by 9 +/- 2% throughout the race (P < 0.05). We found three types of significant effects of epidural lidocaine that supported a substantial role for somatosensory feedback from the exercising limbs as a determinant of central command throughout high-intensity closed-loop cycling exercise: 1) significantly increased relative integrated EMG of the vastus lateralis; 2) similar pedal forces despite the reduced number of fast-twitch muscle fibers available for activation; 3) and increased ventilation out of proportion to a reduced carbon dioxide production and heart rate and increased blood pressure out of proportion to power output and oxygen consumption. These findings demonstrate the inhibitory influence of somatosensory feedback from contracting locomotor muscles on the conscious and/or subconscious determination of the magnitude of central motor drive during high intensity closed-loop endurance exercise.