The low (book-level) display caused the most strain on muscles and joints, the study published in Human Factors: The Journal of the Human Factors and Ergonomics Society said. Study leader Leon Straker of Curtin University of Technology in Perth and colleagues presented an interactive task to 24 children of normal height, aged 10 to 12. The researchers recorded the children's movements and measured 3-D posture and muscle activity in the neck and upper limb for the high, mid, and book-level displays under conditions that are commonly observed in schools.
''The data collected in this study provide the first detailed description of 3-D head, neck and arm posture, and the associated muscle activity of children reading and entering data with computers and reading and writing with paper, the study authors noted. The researchers believe that the study can prove helpful in developing guidelines for computer use bu children.
Studies conducted on adults are inadequate to address computer-related discomfort in children as they are physically and behaviourally different from adults, they said.