Use of Varied Definitions of Repetition with the Distal Upper Extremity Tool (DUET)

Defining what constitutes a repetition in performance of a task involving exertions of the upper extremity can be difficult due to highly varied activities. In this paper, we examine three different definitions of repetition with the use of the Distal Upper Extremity Tool (DUET). These definitions include Grips Alone (manipulation of an object by the hands), Reps Alone (wrist deviations), and Grips + Reps (manipulations plus deviations). Validation of the DUET tool was performed against an existing cross-sectional epidemiology study for all three definitions. The log of the DUET Cumulative Damage (CD) measure demonstrated strong and consistent associations with five separate distal upper extremity outcomes using each of these definitions of repetition when controlled for covariates including site, gender, age, and BMI (with significant odds ratios ranging from 1.20 – 2.10). Results suggest that DUET may allow for flexibility in the definition of “repetition” and still successfully identify hazardous jobs.