The Development of End-State Comfort Planning in an Object Manipulation Task

End-state comfort (ESC) effect defined as the tendency to assume comfortable postures at the end rather than at the beginning of simple object manipulation tasks. This characteristic has been used to assess the behavioral effects of action\motor planning. The aim of this investigation was to assess the developmental trends in motor planning in a group of typically developing male children aged 3 to 10 years (Mean age:6.06±2.25 years; N=97) and compare with a group of male young adults aged 18 to 24 years (Mean age:20.70±2.13 years; N=20). The participants performed a motor planning task (sword task) in which they needed to grasp a wooden play sword and place it into a slot. The percentage of comfortable end postures in both the critical orientations and the control orientations were evaluated. The results revealed an age effect for the percentage of comfortable end postures in the critical orientations, as evidenced by the finding that older children more often showed the ESC effect compared with younger children, and only 10-year-old children reached the same level of sensitivity to ESC as adults. In sum, the study showed that sensitivity to ESC like adults will develop until 10 years of age in children.