口腔护牙托对上臂三角肌肌力作用的研究

目的：探讨口腔护牙托对上臂三角肌肌力的作用，考察其促进提高运动成绩的可能性。方法：以软质树脂材料，采用直接法分别为8名受试者制作定制护牙托，测试戴托受试者平卧推举5kg重物紧咬时的三角肌前束部和嚼肌的肌电值。将该值经系列转换器输入计算机，进行信息数值化处理并输出肌电积分数值。结果：受试者评价该种护牙托的固位，舒适性和保护性均佳，戴护牙托举重5kg紧咬时的上臂三角肌肌电测试值为1．1600，不戴护托时的测试值为0．6125。前者比后者有明显提高，差异有显著性（P＜0．01），戴护牙托与不戴紧咬时嚼肌的肌电测试值分别烟0．3825和0．2138，前者比后者亦有明显提高（P＜0．01）。结论：戴口腔护牙托紧咬提高嚼肌的肌力，进而反射性作用于上臂三角肌，使该肌的肌力亦得以增强。

The effect of mouthguard on strength of the musculus deltoideus

OBJECTIVE: To investigate the effect of mouthguard on strength of musculus deltoideus and to observe the possibility of its improving sports ability. METHODS: The custom mouthguards were fabricated respectively for 8 subjects with soft resin by direct method. The activities of the musculus deltoideus and masseter were tested by means of electromyograph (EMG), while the subjects lay, made maximum voluntary biting with mouthguard and pressed 5 kg. The EMG potentials were transferred to a computer. The data were handled and the integral values of EMG were exported. RESULTS: The subjects set a great value on the mouthguard's comfort, retention and protection. The EMG values of the musculus deltoideus and masseter of the subjects biting with mouthguards were 1.1600 v/s and 0.3825 v/s, and the values of those biting without mouthguards were 0.6125 v/s and 0.213 8 v/s, respectively. The muscular strength of the former was significantly improved compared with that of the latter (P < 0.01). CONCLUSIONS: Wearing a mouthguard and maximum voluntary biting can enhance the masseter force and reflectively improve the musculus deltoideus strength.