Judge The Backrest In Its Existing Position
Metal base office chairs without back height adjustment need a backrest position that suits the person using them. Ask each participant to sit against the backrest and describe where it makes contact. Continue with a typical task, then check whether the user maintains that contact or moves away from it. Record the observation without assuming that every change of posture signals the same issue. The relevant question is how the existing backrest height relates to the user and activity. Since it cannot be adjusted vertically, a mismatch needs further assessment rather than an instruction to raise or lower it.
Distinguish Height From Other Backrest Functions
A backrest can have several characteristics that must be checked independently. Its vertical position, angle, shape and any separate support element are different assessment points. Compare office chairs without treating the absence of one adjustment as evidence about all the others. If movement is available, follow the instructions and identify exactly what changes. Keep the backrest height finding explicit throughout the trial. This prevents a description such as fixed back from obscuring the narrower supplied fact. It also helps colleagues understand which settings users can change and which parts of the seated fit must work as provided.
