Supracutaneous vibrotactile perception threshold at various non-glabrous body loci

Researchers at the University of Nebraska-Lincoln are currently designing a wearable/portable neutron detector. As an alerting mechanism, the device will transmit vibration to the wearer's skin in the presence of hazardous levels of neutron radiation. The present study was designed to help in the ergonomically correct body placement of the neutron detection device while providing numerical values for vibratory thresholds at the surface of various non-glabrous body loci. The aim of the study was to investigate the underlying effects of locus stimulated, amount of subcutaneous fat around a specific body site and gender on low frequency vibration thresholds. Thirty-six participants, who were categorised by both dichotomous body fat group (high or low) and gender, were tested at 24 loci orthogonally located around six body sites: head; neck; upper arm; wrist; waist; ankle. The results indicated that frequency threshold depends significantly on the locus stimulated (p=0.001). The nape of the neck had the greatest sensitivity to low frequency stimulations, while the loci around the waist were least sensitive. Also, body fat significantly affected ability to perceive vibratory stimuli (p=0.048), with the mean frequency threshold of the low body fat group lower than that of the high body fat group. There was no statistical difference in thresholds with gender.