Left- versus right-hand tracking performance by right-handed boys and girls: examination of performance asymmetry.

This study compared left- versus right-hand performance within healthy, right-handed, 8- or 9-yr.-old boys and girls on a finger-movement tracking task. 38 boys and 38 girls were randomly assigned to use either the left hand first and right hand second or vice versa in tracking a sine wave target with extension and flexion movements of the index finger. The data were analyzed with a three-way analysis of variance with repeated measures followed by pair-wise comparisons with a Bonferroni correction. Analysis yielded a significant hand x test interaction and a significant improvement for subjects tracking with the right hand on Test 1 and left hand on Test 2. No significant change occurred for subjects tracking with the left hand on Test 1 and right hand on Test 2. No interaction was observed with sex as a factor. This study suggests that asymmetry of performance favoring the left hand occurs in right-handed boys and girls during finger-movement tracking.