Vibratory perception threshold in the lower extremities. Normative values.

Objective was to obtain normative values for the vibratory perception threshold (VPT) in the lower extremities and study the dependence of VPT on various physiological factors. Thirty healthy volunteers: 10 men and 20 women entered in the study. The VPT for 8, 16, 31.5, 63, 125, and 500 Hz were estimated on the right and left external malleolus using the B&K vibration threshold meter, modified type 1800, and the threshold tracking method. The applied static force could not be controlled. The measurements were repeated twice. VPTs expressed as mean +/- SD were as follows: 8 Hz 109 +/- 3.4 dB, 16 Hz 112 +/- 4.1 dB, 31.5 Hz 116 +/- 6.2 dB, 63 Hz 116 +/- 8.4 dB, 125 Hz 117 +/- 8 dB, 250 Hz 125 +/- 9.3 dB, and 500 Hz 136 +/- 13.1 dB. A nomogram was constructed with reference ranges of VPTs for individual frequencies, from which the profile of vibratory perception thresholds can be seen. Moreover, a global index was calculated as a sum of VPTs for individual frequencies. Its reference value was 840 +/- 52 dB and it varied in repeated measurements by up to 9%. No statistically significant difference of VPTs between the right and left side and between the 1st and 2nd examination was found. A tendency to the increase of VPTs with age was observed, which in males reached statistical significance for frequencies 16, 31.5, 63, and 125 Hz.