Vrooijink, M.M.A. (Merle) (2017) Open- and closed-loop control during goal-directed reaching movements with perturbations in children 5- to 11-years of age. thesis, Human Movement Sciences.
Full text available on request.Abstract
To interact appropriately with the dynamically changing environment, children must continuously correct their movement patterns, even after a planned movement has been initiated. As a result reaching movements often need to be adapted to reach the goal successfully. A convenient way of studying goal-directed reaching and observe adaptations is by using perturbations. Exposing children to visual perturbations during goal-directed reaching movements, force children to use closed-loop control in order to adjust reaching trajectory to the goal. It is surprising that few studies have investigated the development of reaching in the occurrence of perturbations. In this study, we were particularly interested in age related changes during goal-directed reaching movements in the nature of open- and closed-loop control in response to visual perturbations. Twenty-one healthy university students and forty-seven children, ranging from 5 to 11-years of age, were separated into four groups; 5- and 6-year olds, 7- and 8-year olds, 9- and 10-year olds and students aged 20-25. Participants made ninety goal-directed reaching movements to a target that could switch location to the left or to the right after initiation of the movement. The kinematics acceleration time, deceleration time, time to correction, post correction and pointing errors of the trajectory of the index finger were observed. Time to correction was defined as the moment during movement in which a correction took place away from the initial (central) target toward the new peripheral target. Post correction time was defined as the time needed from time to correction until end of the movement. Results showed that acceleration time did not differ in age groups. This showed that the duration of open-loop control remained the same over age. Deceleration time, time to correction and post correction time decreased linearly over age. It was concluded that open-loop control is present before the age of 5 and develops not by becoming faster but by refinement of the internal model. This refinement of the internal model accounted for a shorter closed-loop phase, because less feedback was needed. As a result the duration of closed-loop control decreased linearly over age. Key words: goal-directed reaching, development, motor control, open-loop, closed-loop, adaptation, perturbations
| Item Type: | Thesis (UNSPECIFIED) |
|---|---|
| Supervisor name: | Golenia, drs. L. and Bongers, dr. R.M. and Schoemaker, dr. M.M. |
| Faculty: | Medical Sciences |
| Date Deposited: | 11 May 2022 10:01 |
| Last Modified: | 11 May 2022 10:01 |
| URI: | https://umcg.studenttheses.ub.rug.nl/id/eprint/3279 |
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