Effect of Rater Background on Objectivity of the Rapid Upper Limb Assessment

Abstract

Insufficient evidence of reliability testing of work-related assessments is a major concern in the field of ergonomics. Objectivity, the ability of a scale or test to be used by raters to come to the same conclusion when examining the same thing, is one type of reliability. This paper presents a detailed exploration of the objectivity of a postural rating scale, the RULA, or Rapid Upper Limb Assessment (McAtamney & Corlett, 1993). Four video tasks were presented to 3 groups of raters. Variables examined were rater years of experience in movement observation, rater experience using the RULA, and rater training in use of the RULA. Objectivity was not identified in any variable. Main effects were present for all variables. Based on the rater sample and the data collected, the RULA cannot be considered an objective tool for communicating or comparing information between raters.