Neck posture and muscle activity with and without head support in a reclined sitting posture when watching IFE

In designing a headrest it is important to define the ideal head position and neck angle. There is literature on the ideal head position, but not in the context of watching IFE in a business class aircraft seat. In this study (n=21) the neck muscle activity (EMG), expected long-term comfort and head/neck inclination were studied in a reclined position (as is possible in business class) when watching IFE in the condition of with and without head/neck support. It appeared that there were no significant differences in EMG between both conditions. However, the posture was significantly different; without head support by a headrest the head was found to be more upright. Expected long-term comfort was rated highest in the condition with a headrest. The fact that no difference was found in EMG indicates that humans tend to look for a head position that is neutral, in the sense of minimal (muscle) effort. Head support in a reclined position may have a positive psychological effect on the user.