Effect of socks on the assessment of vibration sensation.

Objective. To investigate the difference between the measurement of vibration sensation without and with socks. Material and Methods. Fifty healthy volunteers (H group) and 19 patients with diabetic polyneuropathy (PNP group) were included. The sites of measurement were the great toe (GT) and medial malleolus (MM). A standard 128 Hz tuning fork was used in the measurements. Results. Mean duration of vibration sensations without and with socks was as follows: in the H group, 19.4 ± 4.2 and 19.5 ± 4.2 s at GT and 15.1 ± 3.3 and 14.6 ± 3.3 s at MM; in the PNP group, 13.4 ± 3.8 and 12.7 ± 4.1 s at GT and 11.9 ± 3.8 and 11.7 ± 3.4 s at MM. No significant difference was found between the measurements without and with socks, except those found at the MM in group H (P = 0.02). This significant difference was further analyzed in terms of effect size which was concluded to be practically insignificant (Cohen's d < 0.2). Shorter mean vibration duration was measured at MM as compared to GT that could be explained by the damping effect. Conclusions. Wearing socks of moderate thickness does not have any important effect on the duration of vibration sensation. This might be considered as a reflection of the remarkable properties of vibration sensation.