抄録
The aim of this study was to investigate the effect of touch screen installation position and button size on body posture and workload. Ten students (five males and five females) participated in this study. The subjects utilized a touch screen with different installation height (50, 65, and 80% of stature), tilt angle (0°, 45°, and 90° from the horizontal plane), and button size (a square with a side of 10, 20, and 30 mm). The joint angles during the tasks were measured to calculate the joint moment ratios (JMRs) of seven joints: the neck, shoulder, elbow, wrist, lumber, hip, and knee. The subjective scores of ease of operation and visibility were also measured. The results showed that JMRs of trunk and lower limb were higher than that of upper limb. The smaller button size worsened the JMR and the subjective evaluations. The smaller tilt angle improved the maximum JMR and the subjective evaluations in the range of the lower installation height, whereas the larger tilt angle was preferable in the higher installation height. The optimal installation height and tilt angle for the workload reduction were in 68–74 % and 45°–60° ranges, respectively. It is preferable to decrease the tilt angle for the button size of 10 mm by 6 ~ 8° compared with the size of 30 mm.
