Measuring pressure distribution under the seat cushion and dividing the pressure map in six regions might be beneficial for comfort studies of aircraft seats.

Seat pressure maps are often used to evaluate comfort of the users. In this study, we explored the relationships between pressure maps and comfort/discomfort of users in aircraft seats with a focus on a new 6-division method on the pressure maps collected at the bottom of the cushions. An experiment was designed where three cushions with identical shapes but different stiffnesses were prepared. 33 subjects joined the experiment and after sitting on each cushion in 4 postures, they completed comfort questionnaires. Pressure maps on the top as well as the bottom of cushions were collected and analysed. Results indicated that measures on the proposed 6 divisions, especially on the distal posterior thigh regions and regions close to ischial tuberosity of the bottom pressure maps, had larger correlation values to comfort scores compared to other division methods. Practitioner summary: The relations between comfort/discomfort and seat pressure maps collected from the top/bottom of three cushions were studied with 33 subjects in four postures. The distal posterior thigh and ischial tuberosity regions in the proposed 6-division of the bottom pressure maps had larger correlation values to comfort/discomfort compared to other methods.

Comfort and discomfort during smartphone use on a bed.

BACKGROUND: The number of smartphone users is immense. People can do ever more with a smartphone. Smartphones are used everywhere, including in bed and on the sofa. The awkward postures taken in these situations affect comfort and discomfort. In designing a bed, it might be useful to know which position is comfortable for smartphone use on a bed. OBJECTIVE: The objective was to define the most comfortable trunk angle for smartphone use on a bed. METHODS: To study comfort and discomfort, 52 participants were asked to use the smartphone on a bed. The trunk angle of this bed was adjusted to 6 positions from flat to upright and for each angle the comfort and discomfort was recorded. RESULTS: The results showed that the participants prefer a trunk angle range around 120 and 142 degrees. At the best trunk angle 29% of the participants felt comfort in the legs, 25% in the upper back and 16% in the shoulders. However, in this position 36% also mentioned discomfort in the lower back and 24 % in the neck. CONCLUSIONS: For smartphone use a bed is preferable which enables a trunk angle of around 120-140 degrees. For the legs this is comfortable. However, for the neck and upper back the problem of discomfort still needs attention.

Differences and similarities in comfort and discomfort experience in nine countries in Asia, the Americas and Europe.

In order to investigate differences in comfort and discomfort experiences amongst different regions of the world (America, Asia and Europe), a cross cultural study was performed. A questionnaire was sent to participants out in nine countries (Brazil, Canada, the USA, China, Indonesia, Thailand, Germany, Italy and the Netherlands). In total 795 participants completed the questionnaires. All countries score the comfort of a luxurious bed higher than a simple bed, first-class seats higher than economy class and all countries rate the comfort lower when the duration of sitting increases. The study suggests that in the USA and Canada softer beds, hammocks, more luxurious seats and softer pillows are scored as more comfortable compared with the other countries. There are indications that China and Germany prefer a harder mattress than in the other countries. For pillows, the differences between countries are large, which might show that much is influenced by habitude or hesitation to use something new. The Asian countries score the comfort of a brace neck pillow higher, which might be because these participants better realise the benefits better or feel less concerned to wear something that might give the appearance of an orthotic device. Further studies are needed to confirm these suggestions. The study shows that obvious differences are seen in all countries, which makes the construct of comfort internationally comparable. Practitioner summary: In designing and manufacturing globally, it is important to know how different parts of the world experience (dis)comfort. This study did not show large cultural differences amongst nine countries. Some differences emerge regarding pillows, perhaps as differences in sleeping habits play a role. Abbreviations: MANOVA: multivariate analysis of variance; VDA: Vargha and Delaney's A statistic; USA: United States of America.