Reliability of the Distal Upper Extremity Tool (Duet)

Abstract

Musculoskeletal disorders (MSDs) are medical conditions affecting muscles, tendons, vertebrae, and nerves. These disorders, particularly those affecting the upper extremities, are a significant concern for industries due to their prevalence and the high costs associated with treating them. Several ergonomic exposure assessment tools are available for assessing occupational exposure to physical risk factors associated with upper extremity MSDs. A promising observational risk assessment tool that applies material fatigue failure theory to address MSDs of the distal upper extremity is the Distal Upper Extremity Tool (DUET). For occupational safety and health practitioners to use an exposure assessment tool most effectively, it must be reliable. Although DUET’s cumulative damage measure showed strong associations with upper extremity outcomes using data collected in a cross-sectional epidemiological study, the tool’s reliability has not been assessed. The objectives of this dissertation were to 1) complete a thorough reliability analysis of DUET; 2) investigate the tool’s usability and identify potential improvements to improve rater reliability; and 3) introduce a mobile application version of DUET and evaluate its usability. Results indicated that the web-based version of DUET suffers from usability weaknesses, leading to poor inter- and intra-rater reliability among both expert and novice users. Consequently, a mobile application was developed to address these weaknesses. While the mobile application showed improved performance over the web-based version, the improvements were modest. The primary finding of this dissertation is that DUET has poor reliability, requiring additional development and evaluation. Practical implications and recommendations for future work are discussed.