Assessing age differences in touchscreen pointing movements using the method of ballistic movement

To enhance the use of touchscreens for the elderly population, this study tested the ballistic movement method for assessing age-related differences when executing pointing movements. Six old and six young healthy participants performed ballistic movements of specific distances on a modified touchscreen monitor. The measured data of constant errors, variable errors, and movement time were statistically analyzed and fitted using the ballistic movement models. Except that the older participants aimed at approximately 4mm above where the young participants did, no significant aging effect was found on ballistic movement time and endpoint variable errors using analysis of variance. The two ballistic movement models predicted well the measured data of movement time and variable errors, except for the vertical variable error committed by the older participants. The ballistic movement method can reveal detailed differences in age and separately predict motor properties of speed and accuracy, helping design target sizes for specific populations.