Changes in manual dexterity following short-term hand and forearm immersion in 10 degrees C water.
BACKGROUND
Following accidental immersion in cold water, the chance of survival through the initial short-term period may depend on manual dexterity for survival tasks. We aimed to study the time course of impairment of manual dexterity during the initial stages of immersion.


METHODS
We investigated gross (manipulating harness buckles) and fine (Purdue Pegboard Assembly) manual dexterity of 11 male and 15 female subjects with either no immersion (Control) or after immersion of right and left hand and forearm in 10 degrees C water for 30, 120, and 300 s. Exposure lengths were presented in a counter-balanced order in a single session.


RESULTS
Mean local skin temperature decreased significantly with cold-water immersion, with the amount of cooling proportional to the length of exposure. Buckle test times increased significantly from 9.1 +/- 3.0 s during Control to similar values of 19.5 +/- 11.1 s and 18.14 +/- 12.1 s after 120 and 300 s of immersion. Pegboard scores were significantly lower at 40.2 +/- 7.6 pieces following 300 s of immersion compared with Control and 30 s values of 49.0 +/- 6.4 and 47.2 +/- 6.9 pieces, respectively.


CONCLUSIONS
It is concluded that fine and gross manual dexterity were rapidly and progressively impaired with short-term cold-water immersion. Therefore, efforts must be made to protect the hands/forearms from cold and to ensure survival equipment manipulation requires as little dexterity as possible.
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D003080:Cold Temperature / Q000009:adverse effects*; D005260:Female; D005542:Forearm / Q000503:physiopathology*; D006225:Hand / Q000503:physiopathology*; D006801:Humans; D007035:Hypothermia / Q000503:physiopathology*; D007101:Immersion / Q000009:adverse effects / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D013997:Time Factors