Changes in threshold values of finger vibration sensibility depending on differences in measurement conditions.

Investigations of the threshold of vibratory sensibility were carried out in 90 subjects searching for its relation to age, sex, hand and finger tested. It was found that this sensibility to vibrations of 15 and 31 HZ frequencies was higher in women than in men, in the right hand than in the left one, and in blind subjects than in those with normal vision. On the other hand, in the frequency range from 62 to 500 Hh the vibratory sensibility threshold was higher in women, blind subjects with good vision and in the left hand. In boys the threshold of the vibration sensibility was slightly lower than in men. No differences were found between the vibratory sensibility threshold in the fingertips of the 2nd, 3rd, and 4th fingers of both hands. Application of the stimulus at increasing frequency and intensity was accepted as the best method of determining the threshold of vibratory sensibility. The optimal temperature of the vibrating rod was accepted to be 303.2 K (30 degrees C) and the optimal pressure exerted by it was about 1 N (100g).