The effects of normal human variability and hand activity on sensory testing with the full Semmes-Weinstein monofilaments kit.

The first part of this study aimed to determine the effect of human variability on assessment using Semmes-Weinstein monofilaments. Fifteen healthy subjects were tested using a full monofilament kit of known calibration. When the subjects were retested, they responded to a different filament 48% of the time. The second part of the study aimed to determine the effects of vigorous hand activity on sensation, as measured with Semmes-Weinstein monofilaments. Forty randomly selected healthy subjects were assessed before and after they performed a brief, standardized gripping activity. After hand activity, the subjects responded to a different filament 53% of the time. In both parts of this study, the changes in monofilament results were random in direction and magnitude. The number of changes did vary between test sites, the radial nerve sites being most variable and the ulnar nerve sites least variable. It is concluded that the results of testing with the five smallest monofilaments in the full Semmes-Weinstein kit were not reliable in normal subjects and that they did not detect change in sensory function in normal subjects.