Effect of vibration on tactile sensitivity

Tactile hypersensitivity is a common sequela of traumatic hand injury. Vibration is used clinically to reduce this hypersensitivity. The purpose of this study was to determine if vibration has an effect on tactile threshold and if so to determine the duration of that effect. Mean tactile thresholds were determined for 24 healthy adults by means of a pressure aesthesiometer. The experimental group (6 men, 6 women) received 10 minutes of vibration. Mean tactile thresholds were redetermined at the end of the 10-minute treatment period in the experimental group and after a 10-minute rest period in the control group (6 men, 6 women). Thresholds were also redetermined at 5-minute intervals for the next 20 minutes in all subjects. The experimental group showed a significant change in mean tactile threshold after 10 minutes of vibration (p less than .001). This difference remained at 5 (p less than .001) and 10 (p less than .05) minutes postvibration but not at 15 and 20 minutes. No significant change in mean tactile threshold was found in the control group. The results indicate that vibration does increase tactile threshold in "normal" hands and the effect lasts for at least 10 minutes. The application of this information to the clinical setting is discussed.