Upper limb injuries and handedness plasticity.

In a questionnaire survey of 9591 men between 17 and 27 years of age, there was an association between present handedness score and report of an earlier injury causing a temporary shift of hand use. The proportion of weak right-handers was higher among those who reported injuries. Overall, there was no association between left-handedness and injuries. Nevertheless, injuries occurring before the school attendance age, which concerned only a very small fraction of the respondents, were associated with an increased frequency of left-handedness. The data emphasize the plasticity of human handedness, and do not suggest that innate left- or non-right-handedness is a risk factor for accident occurrence.