Normative values of two-point discrimination for lower limb dermatomes in healthy young adults and its correlation with gender and body mass index

Abstract

Background and Aim: Two-point discrimination (TPD) is a useful test for assessing cutaneous sensation. Sensory testing devices for testing TPD values have shown to be valid and reliable in the measurement of the functional sensitivity of the hand and its relativity to touch perception. Evaluation of TPD in the lower extremities is debatable because of dearth of information available in the literature about normative values. The aim of this study is to identify the normative values of TPD of lower limb dermatomes in young, healthy individuals and analyze its relationship with body mass index (BMI) and gender. Materials and Methods: A total of 150 participants of the age group 18–25 undergoing graduation program were included in this study. They underwent TPD test for lower limb (L1 to S2) dermatomes, using a baseline esthesiometer. The Spearman's ratio test was used to find the relationship between BMI and TPD values. The Mann–Whitney U-test was used to compare TPD values according to gender. Results: The normative value ranged from 1.46 ± 1.27 to 2.61 ± 1.45 in lower limb dermatomes. The minimum value noted was at the S1 dermatome (left) and the maximum at the L2 dermatome (left). In the sidewise analysis of TPD, the median values of both sides were approximately the same. There was a definite correlation (P < 0.05) between female gender and TPD; however, there was no significant correlation between BMI and TPD. Conclusion: This study suggested that women are more perceptive in appreciating TPD values than men. Moreover, TPD values do not vary according to BMI or right and left sides.

Keywords

• esthesiometer
• cortical sensation
• dermatomes
• sensory examination
• two-point discrimination