Abstract
Desk sharing in offices has become recently a trend due to the wide spread use of notebook computers. However, they are not always comfortable to use either for reading or typing. We measured the most suitable seating conditions for working with notebook computers. Within the range of heights from the 5th percentile of young females to the 95th percentile of young males, the following optimal conditions were determined. The angles of the keyboard, lower backrest, upper backrest and seat are 10°, 68°, 79° and 10°, respectively. The depth of the middle part is shortened to 354 mm for short user. The depths of both outside sections are lengthened to 378 mm, with inclined lateral supports (maximum angle 35°) for tall user. To allow the display to be comfortably read, the seat height must be 350～410 mm, which is lower than that for conventional office chairs. Evaluations showed that when using this prototype seat in a working environment for 40 minutes, muscle activities in the shoulder and back, and leg swelling were reduced to those when using a conventional office chair, without any decrease in work efficiency. Also, forward tilting of the head decreased by 9° and the shoulder elevation was improved.
