Careful attention must be paid to anthropometrics when manufacturing seating for diastrophics. It is not a matter of simply downsizing a normal office chair as if manufactured for a child. Little people do not have the proportionality of limbs demonstrated throughout the population at large.

When fitting a little person for a chair, the most important measurement is the popliteal-to-buttock length (back of knee to back of buttocks). In this case study, this person’s popliteal-to-buttock was 8½”. Obviously a standard 18” deep seatpan would prevent her from ever contacting the backrest and getting any lumbar support. Sitmatic manufactured a PS seat at 16” deep, but this would have been still too deep. It was impossible to make the seatpan any shorter because the mechanism underneath the chair, with a 10½” length, would protrude out and hit the occupant in the back of the legs. Sitmatic solved the problem by increasing the backrest thickness 8” by adding multiple layers of foam beneath the contoured top layer.

Because the worksurfaces were at a standard 29” height, Sitmatic originally manufactured a chair with a footring to provide foot support. After trying the chair , we discovered this lady experienced discomfort if her knees were flexed more than 30°. Sitmatic solved the problem by custom bending a footbar to support her feet at the proper angle. A lower seat height cylinder was used to allow easier ingress and egress. An air lumbar was installed to fine tune the lumbar shape. Wide armrest caps, that rotate in, were used to accommodate a narrow elbow to elbow distance.