How should a seated workplace with a tiltable chair be adjusted?

For a tiltable office chair, subjective height preferences may be different to those for conventional fixed-seat chairs, due to altered biomechanics. These preferences, with a tiltable chair and associated table, have been investigated with a total of 108 subjects. To determine the shortest possible way to obtain reliable height measurements, a study (n = 10) was undertaken. It was demonstrated that two days of measurement seem necessary, the first day involving both a too-high and a too-low start position, the second day only a too-high one. Preferences were measured for each of four groups, one (n = 21) accustomed to and another (n = 35) unaccustomed to a tiltable seat; a third (n = 23) was composed of children and the fourth group (n = 19) was making large-scale drawings. When accustomed to the seat, the subjects preferred a greater seat height. The children's seat-height preference was relatively equal to that of adults, whereas their preferred relative table height was greater, most evidently so with decreasing age. The greatest relative seat height was preferred in connection with large-scale drawings. For desk work it is recommended that the seat height should be approximately 3-5 cm above popliteal height, including shoe heels, and the table height 4-6 cm above the actual elbow height.