In this study, we aimed to examine the electromyography threshold (EMGT) of the respiratory muscle and accessory respiratory muscles. Sixteen healthy men underwent an incremental exercise test at 15 W/minute to the end point. Expired gases and electromyograms of the respiratory and lower limb muscles were measured. The breakpoints for the EMG and expired gas data were analyzed using a segmented regression model. EMGT of the sternocleidomastoid and diaphragm was significantly more delayed than the ventilation threshold (VT) (287.94 s, 288.15 s vs. 185.5 s, p = 0.028 and 0.044, respectively). The EMGT of respiratory muscles and VT were not related, though EMGT of rectus femoris and vastus lateralis correlated with VT (r = 0.854, p < 0.001; r = 0.657, p = 0.011, respectively). EMGT of respiratory muscles may be influenced by multiple factors, such as central command and afferent input of mechanical stimulation from muscles, in addition to VT-induced changes in metabolic dynamics.

在这项研究中，我们旨在检查呼吸肌和辅助呼吸肌的肌电图阈值 (EMGT)。16 名健康男性以 15 W/分钟的速度进行了增量运动测试，直至终点。测量呼吸和下肢肌肉的呼出气体和肌电图。使用分段回归模型分析 EMG 和呼出气体数据的断点。胸锁乳突肌和膈肌的 EMGT 明显比通气阈值 (VT) 延迟更多（分别为 287.94 秒、288.15 秒和 185.5 秒，p = 0.028 和 0.044）。呼吸肌 EMGT 与 VT 无相关性，但股直肌和股外侧肌 EMGT 与 VT 相关（r = 0.854，p < 0.001；r= 0.657，p = 0.011，分别）。呼吸肌的 EMGT 可能受多种因素的影响，例如中央命令和肌肉机械刺激的传入输入，以及 VT 引起的代谢动力学变化。