Limits of two-point discrimination ability in the lower limb in young adult men and women.

The purpose of this study was to determine the limits of two-point discrimination ability in the lower limb in a sample of healthy, young adult men and women. Eleven different areas of skin were tested with a commercially available compass-type instrument to determine the shortest distance at which two simultaneously applied, nonpainful, light-touch stimuli could be perceived. Mean two-point discrimination values in the lower limb ranged from 43.6 mm for skin overlying the medial surface of the leg to 6.6 mm on the plantar surface of the tip of the great toe. The results also demonstrated interindividual variation in two-point discrimination for a given area of skin. In the majority of skin areas tested, mean values obtained from men and women were essentially the same. In several of the test areas, however, women were significantly better than men in their two-point discrimination ability. The observed intraindividual and interindividual variation suggests that although two-point testing is a useful clinical tool, caution is necessary when interpreting the results from patients with alterations in cutaneous sensibility.