Aircraft passenger comfort based on muscle activation and perceived discomfort during long flights

OBJECTIVE: The purpose of this study was to investigate the comfort of aircraft passengers during long flights and to determine the effects of the seatback angle and the seat pitch on passengers' upper body muscles (neck, shoulder, and lower back) and subjective comfort. METHODS: All subjects sat on an aircraft seat for 2 h with different levels of seatback angle and seat pitch. Subjective discomfort scores and root mean square (RMS) and mean power frequency (MPF) values were used to evaluate muscle fatigue, and all data were calculated for every 15-min interval. RESULTS: Significant increases of MPF for all three muscles were found at 30 min, along with significant increases in the perceived levels of discomfort (PLD) over 2 h. Besides, a 120° seatback angle and a 34 seat pitch resulted in lower PLD values for the lower back and hip areas than smaller ones (significant difference). DISCUSSION: It took around 30 min before pronounced discomfort in the upper body regions occurred during flight. The larger parameters of seatback angle and seat pitch may significantly contribute to the easing of subjective discomfort. Moreover, a decrease in MPF coupled with a concomitant increase in RMS does not appear to be a reliable indicator of discomfort rate. The need for further development of discomfort indicators which are more directly related to muscular activation is recognized.