Evaluation of physical and environmental working conditions of underground coal mines within the framework of ergonomics

This study evaluated the physical and environmental working conditions of underground coal mines and the occurrence of musculoskeletal symptoms (MSS). The data from 236 miners were collected and analysed by using the chi-squared test, Fisher's exact test, and the Mann-Whitney U test. Results showed that mine design was inappropriate (e.g., lack of appropriate tools and inadequate working conditions, etc.). Miners had to deal with excessive job demands (e.g., inappropriate work pace, high manual material handling (MMH), and repetitive tasks). Most miners (85.5%) experienced pain/discomfort in at least five body regions. Low back (82.6%), upper back (80.9%), shoulder (77.5%), knee (67.8%), and ankle/foot (62.3%) complaints were the most frequently reported symptoms. The low back symptoms were associated with MMH tasks, shoulder symptoms were associated with poor lighting conditions, and ankle/foot symptoms were associated with inappropriate work pace, inadequate space, pushing/pulling/dragging tasks, and bending/twisting activities. The findings help to understand the working conditions of miners and highlight the need for multifaceted interventions to improve the workstation design and work organisation.