The Comparison of the Effect of Age and Object Location on the Hand Selection in the Reaching Task

The purpose of this study was to investigate the effect of age and object location on the hand selection in reaching task 120 right-handed children, adolescents and adults were selected as aur as a participant. Handedness was determined by Stanley-corn (1992) handedness Questionnaire. The tasks included lifting, reaching, and making actual use of three different objects. After the participants made 6 attempts, the objects location was changed. Each of the participants had to make 18 attempts. Data were analyzed through Two-way ANOVA and the significant level of 0/05 was used for all statistical analysis. The results showed that there is no significant difference in mean frequency of reaching in right hemi space among children, adolescence and adults (p≥ 0/05). But, there is a significant difference in the mean frequency of reaching in middle line crossing and left hemi space among children, adolescence and adulthood) p≤ 0/05). The results also indicated that, Children, compared with adults and adolescents, used non-preferred hand in middle line crossing and left hemi space in reaching objects. In the same way, adults compared with adolescents, used non-dominant hand when reaching objects in middle left hemi space. So, in childhood, it is probable that the consolidation of the dominant-hand has not been established; in adolescence, however, relying on dominant-hand to do the tasks increases. In adulthood, regarding the object location, tendency of using both hands, dominant- and non-dominant hands, increases.