Sensory, motor, and pain thresholds for stimulation with medium frequency alternating current
Sensory, motor, and pain thresholds for stimulation with medium frequency alternating current
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DOI：
10.1016/s0003-9993(98)90006-5
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发表时间：
1998-03-01
影响因子：
4.3
通讯作者：
Robertson, VJ
中科院分区：
文献类型：
--
作者：
Ward, AR;Robertson, VJ
目的：探讨不同频率的交流电对正常人感觉、运动和痛觉阈值的影响，建立最优的运动刺激频率，将受试者的不适感降至最低。设计：两组11名受试者的重复测量设计。设置：使用实验室环境。受试者：受试者为符合纳入标准的志愿者。干预：对每个受试者施加20种不同载频的交流电，频率在1~35 kHz之间，均调制在50赫兹。对于一半的受试者，频率按顺序增加或减少(第二次颠倒)，另一半的受试者在每个场合以不同的随机顺序施加频率。主要观察指标：记录每个施加频率的感觉阈值电压。结果：在1 kHz到大约10 kHz之间，感觉、运动和痛觉阈值随着频率的增加而降低。当频率超过10 kHz时，阈值升高。痛觉阈值/感觉阈值的比值在所研究的范围内随着频率的增加而系统性地增加。相比之下，痛阈值/运动阈值的比值在频率为10 kHz时出现明显的最大值。结论：对于舒适的感觉刺激，高频交流电是较好的选择。在大约10 kHz的频率下，疼痛和运动刺激之间的区别最大。这表明，舒适运动刺激的最佳频率接近10 kHz，这是一种最不可能引起疼痛纤维刺激的频率。(C)1998年由美国康复医学大会和美国物理医学和康复学会主办。
Objectives: To investigate the effect of frequency of alternating current on the sensory, motor, and pain thresholds in normal subjects, and to establish the optimal frequency for motor stimulation with minimal subject discomfort.Design: A repeated measures design using two groups of 11 subjects.Setting: A laboratory setting was used.Participants: Participants were volunteers who met the inclusion criteria.Interventions: Alternating current with 20 different carrier frequencies between 1 and 35kHz, all modulated at 50Hz, was applied to each subject on two separate occasions. For half the subjects, the frequency was increased or decreased sequentially (reversed on second occasion), and for the other half, it was applied in a different random order on each occasion.Main Outcome Measures: The voltage at the sensory threshold was recorded for each applied frequency. This was subsequently repeated for motor and pain thresholds.Results: Sensory, motor, and pain thresholds decreased with increasing frequency between 1kHz and approximately 10kHz. Above 10kHz, the thresholds increased. The ratio pain threshold/ sensory threshold increased systematically with increasing frequency over the range examined. By contrast, the ratio pain threshold/motor threshold showed a distinct maximum at a frequency of 10kHz. Marked accommodation to motor and pain fiber stimulation was observed.Conclusions: For comfortable sensory stimulation, a high frequency of alternating current is preferable. Discrimination between pain and motor stimulation is maximal at a frequency of approximately 10kHz. This suggests that the optimal frequency for comfortable motor stimulation, one that is least likely to elicit pain fiber stimulation, is close to 10kHz. (C) 1998 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation.