User-chair fit index (UCFI): An ergonomic evaluation tool for user-chair compatibility

Abstract

VDT work is associated with a high degree of postural constraint, thus, requires maximum flexibility to be built into the workstation setup so as to compensate for the lack of flexibility in the job design. In workstations where static postures are unavoidable, like a VDT workplace, the risk can be reduced by designing to accommodate the limitations of human anatomy. Work chair has a major role to play in the comfort/discomfort experienced at the workplace. User-Chair Fit Index (UCFI) is an ergonomic tool developed on the lines of the Likert Summated Rating Scale for checking the aptness of the work chair by assessing the fit between user and work chair. UCFI, initially, was developed with 36 items, and was evaluated by a panel of 50 experts i.e. 25 engineers and 25 furniture designers for its appropriateness in measuring the desired construct. The tool with 36 items was administered for pilot study on 200 VDT operators working in IT industry. The item correlation and item differences were computed for item analysis and after dropping items with low t-values, final set of 26 items was selected, which was given to 1000 male respondents in the age group of 25–35 years, working in the IT industry, selected randomly. The final data used for the standardization of the tool was derived from 839 respondents, after eliminating the incomplete response sets. The tool was validated to ensure its dependability in recognizing the fit between the user and work chair in the VDT workplace. The reliability estimates and validity indicate that the scale was highly reliable and valid for identifying the user-chair fit in the VDT workstation. z-Score norms were developed for interpretation of the raw scores.