The ergonomic office chairs selected for inclusion in the study were sourced from various international manufacturers.
All of the chairs included were in widespread
distribution and use at the time of this study. Each chair
was chosen for its differences from the others, whether it
was as dramatic a difference as its fundamental engineering
design or as simple a difference as a variation in the type or
thickness of the seat pans’ foam or fabric. In an effort to
avoid commercialism, no mention will be made of the chair
makes or models. Instead, a brief description of their basic
designs is tabulated with a corresponding ‘‘chair code’’
which is used for chair identification. The chair descriptions
themselves are purposely kept brief and general since
with a sufficient description a knowledgeable ergonomist
could easily recognize many of the chairs. This type of
identification is deemed to be appropriate since the goal of this study was not a detailed investigation of chair design
variables, but rather a comparison of whether basic
differences in chair designs or changes in subject posture
had a greater impact on subject-seat interface pressure
distributions. Table 1 is a list of the chair descriptions and
the corresponding identifier codes used in the experiment.
All chairs had a five-point base, a hydraulic/pneumatic
main support cylinder, a backrest, and armrests.