Do Different Visual Conditions Affect Tactile Acuity at Hand in Healthy Young Adults?

Abstract

Background and purpose: Subjects should not see the area tested during the two-point discrimination (TPD) test. Various methods are used in the literature to hide the test area. However, there is yet to be a consensus on which method is the best. This study investigated the tactile acuity of different methods to obscure the line of vision in TPD testing in healthy young adults. Methods: We evaluated the TPD thresholds of the dominant hand's three regions in 30 healthy young adults under four different visual conditions (two eyes open and two eyes closed). Friedman test and Wilcoxon signed rank test were used for statistical analysis. Results: In all areas tested, the distance required to perceive two stimuli was smaller in the eyes open conditions. 46.70% of the participants reported being more comfortable and distinguishing two points more quickly when their eyes were open. Conclusion: Although the threshold values of TPD are within clinically appropriate ranges in all four visual conditions, we suggest performing TPD testing while the patients' eyes are open. Clinicians may obtain more accurate results during TPD tests if subjects are tested with their eyes open rather than closed.

Keywords

• somatosensory function
• tactile acuity
• touch perception
• two-point discrimination
• young adults

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