Guinea pig soleus and gastrocnemius electromyograms at varying speeds, grades, and loads.
Guinea pig soleus and gastrocnemius electromyograms at varying speeds, grades, and loads.
复制标题
豚鼠比目鱼肌和腓肠肌在不同速度、等级和负荷下的肌电图。
DOI：
10.1152/jappl.1982.52.2.451
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
V. Edgerton
中科院分区：
文献类型：
--
作者：
K. Gardiner;P. Gardiner;V. Edgerton
The purpose of the study was to describe changes that occur in the usage of fast-twitch and slow-twitch guinea pig hindlimb muscles, as estimated using chronically implanted electromyogram (EMG) electrodes, during voluntary locomotion under various conditions. Guinea pigs, in which fine wire electrodes were implanted in soleus (SOL) and lateral gastrocnemius (LG) muscles, were exercised at various speeds (13.4, 26.8, 40.2 m/min), grades (0-30%) and in some conditions loads (50-150 g) on a motor-driven treadmill. Bipolar EMG signals were rectified-averaged (RA-EMG) and analyzed for burst duration, amplitude, and the integral of each burst (IEMG). For each condition and muscle, total IEMG/min (IEMG/step x steps/min) was calculated and expressed as a percent of the maximum IEMG recorded. With increasing speed at 0% grade, the ratio of LG to SOL IEMG, each expressed as percent of maximum, remained constant at about 0.82. An increased stepping rate of 150 (at 13.4 m/min) to 225 (at 40.2 m/min) steps/min was accompanied by a 37% decrease in burst duration in LG and SOL. When the treadmill belt speed was increased from 13.4 to 4.02 m/min at 30% grade, the LG/SOL ratio increased from 0.83 to 1.03, whereas burst duration decreased by 49% (SOL) and 51% (LG). Soleus IEMG did not change significantly with increases in speed or grade; LG IEMG increased significantly with speed at 10% grade and with grade increase at the highest speed (40.2 m/min). These data provide some insight into how modifications of work load on a treadmill affect overall muscle activity and may assist in the interpretation of training-induced muscle biochemical alterations previously noted by other investigators.
