Postural benefits for children and adults when using the mouse next to a small keyboard

Abstract

Studies have shown that there are adverse performance and postural impacts when children use standard, adult-sized computer mice; however, the impact of children using adult-sized keyboards has been less rigorously evaluated. The aim of this study was to investigate whether there were any postural and performance differences when children and adults used the mouse next to a standard 104 key keyboard with a numeric keypad compared to a small, more compact keyboard without a numeric keypad. A total of 42 subjects, including 28 adults and 14 children between the ages 6–8 participated in the study. Subjects were asked to perform a series of standardized point-and-click tasks using a standard-sized mouse with both the standard and small keyboard. During mouse operation arm abduction and forearm rotation were measured using overhead photographs, and mouse performance was characterized by measuring movement times and the time it took to press-and-release (click) the left mouse button. Compared to the standard keyboard, both children and adults had less arm abduction (p < 0.10) and external rotation of the forearm (p < 0.05) when using the mouse next to the small keyboard. When comparing children to adults, children worked with significantly more arm abduction with both keyboards; however there were no significant differences between children and adults in internal and external rotation of the forearm. When comparing performance, children took almost twice as long to move the mouse between targets (p < 0.05) and were slightly faster when operating the mouse next to the small keyboard. In addition, compared to adults, it took children twice as long to press and release the mouse button. The study findings indicate that children would benefit from a postural standpoint if computer manufacturers sold, and schools and parents purchased, computers with smaller keyboards. The two-fold difference between children and adults in the time it took actuate the mouse button indicate that mouse button activation forces may need to be lower for children.