Kowalzik R, Hermann B, Biedermann H, Peiper U
Orthopaedic Clinic, University of Hamburg, Germany.
Foot Ankle Int. 1996 Oct;17(10):629-34. doi: 10.1177/107110079601701008.
The capability for discrimination of vibratory stimuli of the sole of the foot was tested on 12 subjects (6 men, 6 women). Two vibratory stimuli (sinusoidal impulse: frequency, 200 Hz; amplitude, 0.1 mm; duration, 2 sec) were applied at different sites to the sole of the foot. Subjects were asked whether they detected one or two vibratory sensations. The discrimination threshold was defined as the shortest distance at which two vibrations can be differentiated at repeated trials. In addition, the absolute threshold was measured by one plunger (sinusoidal vibration: frequency, 200 Hz; variable amplitude). The values of the absolute threshold (average value, 1.2 microns) were in accordance with the results of other authors. A decrease of discrimination capability was observed along the longitudinal axis of the foot from distal to proximal parts and was about 15 mm at the big toe and 34 mm at the heel. Discrimination at the medial longitudinal arch was inferior to that at the lateral longitudinal arch. This was also true for inverse vibration in which all subjects showed lower thresholds. No relationship was found with respect to thickness of the skin (measured by ultrasound), side of foot, or gender. Determining factors for vibratory threshold might be the density of the Pacinian corpuscles per cm2 as well as their peripheral and central representation. Anatomical or physical factors (e.g., thickness of the skin, impedance of the deeper tissue) can probably be disregarded.
对12名受试者（6名男性，6名女性）进行了足底振动刺激辨别能力测试。在足底不同部位施加两种振动刺激（正弦脉冲：频率200Hz；振幅0.1mm；持续时间2秒）。询问受试者是否感觉到一种或两种振动感觉。辨别阈值定义为在重复试验中能够区分两种振动的最短距离。此外，用一个柱塞测量绝对阈值（正弦振动：频率200Hz；振幅可变）。绝对阈值的值（平均值1.2微米）与其他作者的结果一致。沿足底纵轴从远端到近端观察到辨别能力下降，在大脚趾处约为15mm，在足跟处为34mm。内侧纵弓处的辨别能力低于外侧纵弓处。反向振动也是如此，所有受试者的阈值都较低。未发现与皮肤厚度（通过超声测量）、足侧或性别有关。振动阈值的决定因素可能是每平方厘米环层小体的密度及其外周和中枢表征。解剖学或物理因素（如皮肤厚度、深层组织阻抗）可能可以忽略不计。
