Validity and Reliability of the Modified RULA (mRULA) among Public and Private Office Workers

Abstract

The Rapid Office Strain Assessment (ROSA) is a valid and reliable simple observational tool specifically for computer workers however it does not include muscle/force loads as compared to the Rapid Upper Limb Assessment (RULA), which is the most commonly used tool regardless of occupations. A modified Rapid Upper Limb Assessment (mRULA) has been developed specifically for computer use among office workers, however, its validity and reliability has weak evidence from only a small pool of currently available studies. This study primarily aims to determine the validity and reliability - namely the external validity, internal consistency, and inter- and intra- rater reliability - of the mRULA in the assessment of ergonomic risk factors among public and private office workers. Secondarily, this study aims to compare the ergonomic risk between office workers in public and private companies. This study is a quantitative psychometric study. Data were obtained through video method of participants from the selected public and private companies in their respective office workstations. Two assessors used both ROSA and mRULA tools for two trials. Results determined the external validity thru Pearson Correlation Test based on ROSA, internal consistency thru Cronbach alpha, inter-rater reliability thru Wilcoxon Signed Test, and intrarater reliability thru the Intra-Class Coefficient of mRULA and compared public and private companies thru Mann Whitney U Test. significant difference, either in the public company (Z = -6.218, p value = .000) or in the private company (Z = -2.211, p value = .027), was found between ROSA and mRULA while approaching moderate internal consistency (Cronbach alpha = 0.536) was found.