Movement control and maturation in elementary-grade children.

Serial tapping by 5-, 7- and 9-yr.-old boys and girls, as measured by Fitts' Law, was recorded. 60 Ss performed a reciprocal tapping task and were assessed developmentally via hand-wrist X-rays. No significant relationship was found between the fine motor task and skeletal age. The results of the motor task suggest an improvement in movement time, with age, due to an ability to plan subsequent movements rather than simply an increase in speed of arm movement.