Reliability of Tactile Sensitivity Measurement With Semmes-Weinstein's Monofilaments in Community-Dwelling Adults

Semmes-Weinstein monofilaments (SWMs) are used for the assessment of tactile sensitivity. The aim of this study is to investigate the intra- and inter-rater reliability of the full 20 SWM kit for the assessment of tactile sensitivity at hand level in a large sample of community-dwelling adults.

A consecutive convenience sample of community-dwelling adults was enrolled in an outpatient clinic. By applying stimuli to 5 different locations, according to the dermatomeric levels of the upper limb, a study was designed to test the intra- and inter-rater reliability of the SWM in assessing tactile sensitivity of the hands. Intra-rater reliability was investigated in 2 evaluation sessions; during each session 2 independent examiners performed the test (inter-rater reliability). Test-retest and intra-rater reliability, for each site and for both sides, were estimated with the quadratic weighted kappa index, with 95% confidence intervals. The false-negative responses were also recorded.

A total of 102 participants completed the study. According to the perceived filament, values reached the .70 threshold in terms of inter-rater and intra-rater reliability, except for the dorsal surface of the hand at the base of the thumb in both hands. The number of false-negative responses was 6.1% of all stimuli administered.

The full 20 SWM kit is reliable at the hand level in healthy subjects, when used in groups of individuals. These results are based on a large sample, in a high number of sites. When doing the overall assessment, false-positive responses should be considered.