Considerations for tactile perceptual assessments: impact of arm dominance, nerve, location, and sex in young and older adults.

Purpose: Intact tactile perception is essential to successfully interact with objects. While tactile examinations exist for capturing tactile impairments, recent investigations underscore that these examinations remain insufficient, particularly for adults following a neurological injury. To inform the design of improved tactile assessments, this study comprehensively captures factors that can influence tactile perception in young and older adults who are neurologically intact.

Methods: We examined the impact of arm dominance (dominant/non-dominant), nerve (median/ulnar/radial), location (hand/elbow), and sex (male/female) on thresholds at which electrotactile stimuli could be consciously detected when applied to the skin in 20 young and 14 older right-arm dominant participants.

Results: Significant differences depending on arm dominance were not found in young (p = 0.6781) or older (p = 0.2786) adults. Yet, the nerve tested did yield differing thresholds in young (p < 0.0001) and older (p < 0.0001) adults. In young adults, thresholds were less at the hand than elbow (p = 0.0031). In older adults, the average threshold was greater at the hand than elbow. Importantly, in older adults the threshold at the hand increased with age to a greater extent than at the elbow (p < 0.0001). Thresholds were greater in males than females in young adults (p = 0.0004), whereas no significant sex differences were observed in older adults (p = 0.2560).

Conclusion: This work highlights the importance of addressing numerous factors and their interactions when assessing tactile perception (e.g., arm dominance, nerve, location, sex, age). Findings can inform the design of improved tactile assessments that more accurately capture why impairments arise, including following a neurological injury.