Hand preference and risk of injury among the Northern Finland birth cohort at the age of 30.

The aim of this study is to examine two hypotheses. The first hypothesis proposes that left-handers have a higher injury risk than right-handers. The second hypothesis assumes that ambidextrous people have an elevated risk of injury compared with both right- and left-handers. The subjects of this study, 4107 men and 4461 women, were all born in northern Finland with expected dates for birth in 1966. They filled out a questionnaire at the age of 31. In the questionnaire, 7.9% of the men and 6.1% of the women reported themselves to be left-handers, and 1.7% of the men and 0.6% of the women to be ambidextrous. In addition, 71% of the subjects reported having been involved in at least one injury during their lifetime. There was no significant difference in injury involvement between left- and right-handers or ambidextrous people. The right-handers reported even more injuries in several injury types than did the left-handers. However, men using both hands equally had slightly elevated risk of traffic and home injury, whereas ambidextrous women had slightly elevated risk of work injury compared with right-handers.