Effect of age and height on vibrotactile threshold among 1,663 U.S. workers.

Assessment of vibrotactile threshold has gained application in studies of neuropathies induced by toxic substances, compression, and vibration. The effect of age and height on vibrotactile threshold is of interest for its own sake and for the purpose of confounder control. We have studied the relation between finger and toe vibrotactile thresholds and age and height in five studies carried out by the National Institute for Occupational Safety and Health with vibrometry data (N = 1,663). A unique property of the merged data set was its wide age range from 14 to 82 years (mean 42 years). We demonstrate a J-shaped increase in finger threshold value (expressed on a log scale) with age, with no increase up to age 35 and a linear increase thereafter. For finger threshold, height was not an important predictor. The data were sparser (n = 541) for toe threshold but suggested a linear increase with both age and height. While consistent with prior data, this study provides a better understanding of the relation between vibrotactile threshold and age and height than has been available before. The greater effect of age and height on toe rather than finger threshold is consistent with the hypothesis that the length of the nerve increases susceptibility to peripheral neuropathy.