The Influence of Hand Immersion Duration on Manual Performance.

Objective: To investigate the effect of hand immersion duration on manipulative ability and tactile sensitivity. Background: Individuals in maritime settings often work with hands that have been immersed in water. Although research has shown that hand immersion duration differentially impacts skin adhesion and tactile sensitivity, the effect of hand immersion on manipulative ability has not been directly tested. Given how critical manipulative ability is for the safety and performance of those working at sea, the effect of hand immersion duration on manual performance was investigated. Method: Tests of manipulative ability (Purdue Pegboard, Grooved Pegboard, reef knot untying) and tactile sensitivity (Touch-Test) were completed following no-exposure, short-exposure, and long-exposure hand immersions in thermoneutral water. Results: Compared to the no immersion condition, the Purdue Pegboard performance was reduced in both immersion conditions (short exposure, -11%; long exposure, -8%). A performance decrement was only observed in the short exposure condition (+15% in time to complete task) for the reef knot untying task. There were no statistical differences in the Grooved Pegboard or Touch-Test scores between exposure conditions. Conclusion: Immersing the hands in water decreases manipulative ability except for when object properties reduce the slipperiness between the hand and object. Application: Manual performance in a wet environment may be conserved by designing tools and objects with edges and textures that can offset the slipperiness of wet hands. To maintain safety, the time requirements for working with wet hands needs to be considered.