Global Upper Body Assessment (GUBA) - A new Tool to Identify the Indicators That will lead to the Occurrence of Musculoskeletal Disorders of Light Weight Loads in Seated Position Based Body Mass Index and Postural Strategy

Abstract

Musculoskeletal disorders (MSDs) are increasingly prevalent in industrialized countries, and have a major financial impact. Their prevention requires new ergonomic tools to better understand and assess the risks. The objective was to propose the Global Upper Body Assessment (GUBA) tool for investigating indicators that will lead to the occurrence of MSDs in the workplace, in daily life or at home. GUBA was applied to interaction tasks with handheld digital devices weighing from 0 to 1 kg in a sitting position, with or without support for the upper limbs. The GUBA tool was developed in three stages: 1) modeling to quantify joint parameters, joint torques and reaction forces from subject’s BMI, mass handled, and postural strategy; 2) development of risk scales; 3) computation of the GUBA score. A set of abacuses has been created to enable the user to directly read the GUBA score and the corresponding MSD risk level. The abacuses are very easy to use: simply select the abacus for the situation (sitting with or without support), choose the table corresponding to the mass handled, identify the user's BMI, choose the postural strategy, and finally read the GUBA score at the end of the line. Key words: Musculoskeletal disorders; ergonomic assessment; posture; joint load; support; smartphone; handheld digital devices.