The influence of water immersion on manual performance

Abstract

Individuals working in ocean environments often have to perform motor skills with wet hands. Although one might assume that manual performance is hindered with wet hands, the influence of hand wetness on manual performance might not be straightforward for two reasons: 1) the curve that describes the relationship between hand moisture and the coefficient of friction is bell shaped (Andre et al. 2009) (i.e. intermediate level of moisture is optimal), and 2) increased skin hydration, from immersions in water, enhances skin adhesion (Derler et al. 2012). The purpose of the current research was to investigate how manual performance is influenced by hand wetness and water immersion duration. To that end, participants performed one sensory and three motor tests (Touch-Test, Purdue Pegboard (30s), Grooved Pegboard Task, Knot Untying Task) in three water immersion conditions (Dry Hands; Short Exposure; Long Exposure). We hypothesized that dry hand performance would be higher than wet hand performance. In addition, we hypothesized that a smaller decrement in performance would occur in the long exposure condition in comparison to the short exposure condition. The results showed that Purdue Pegboard performance was higher with dry hands in comparison to both wet hand conditions. In addition, performance in the knot untying task was higher with dry hands in comparison to the short exposure condition but not the long exposure condition. There were no statistical differences in the Grooved Pegboard scores or the Touch-test scores. Overall, this research demonstrates that manual performance is influenced by hand wetness and immersion time.