Biomechanical Risk Factors of the Upper Limbs' Musculoskeletal Disorders among Carpet Weavers in Tunisia: Semi-Quantitative Ergonomic Assessment.

Abstract

Musculoskeletal disorders are one of the most common occupational health problems and one of the leading causes of temporary disability. This study aimed to assess the biomechanical constraints of upper limb musculoskeletal disorders associated with Tunisian weavers' tasks. An ergonomic approach was adopted with a representative sample of Tunisian weavers. First, the activity was observed mainly for identifying tasks and sub-tasks. Then, the biomechanical constraints were assessed based on the Borg scale and the software analyses and encoding of the 2,000 images extracted from the activity video recordings. These analyses were done with the ERGOROM software. Four main tasks were identified (warping of the loom, weaving itself, beating up, and finishing). As for the subtasks, the six most important were thread coiling, shedding and picking, beating up the weft, knotting, cutting, and shearing. Semi-quantitative analysis revealed that weavers spent most of their working time in the constrained neck and upper limb postures. Shoulders were in flexion/abduction during 68.6% of the activity and pinch grip was spread over 83.3% of the working time. Furthermore, elbows and wrists were highly concerned by elevated gestural variability scores. The estimated deployed strength was "medium" to "strong" in 50% to nearly 80% of cases. According to the results, in carpet weavers, exposure to biomechanical constraints at risk of musculoskeletal disorders was high for the various joints and parts of the upper limbs. It is, therefore, necessary to carry out interventional studies for the development of ergonomic hand tools and workstations adapted to the traditional weaver activity.