Risk factors and prevalence of work-related musculoskeletal disorders in metropolitan bus drivers: An assessment of whole body and hand-arm transmitted vibration

Abstract

BACKGROUND: Metropolitan bus drivers have higher prevalence of work-related musculoskeletal disorders (WMSDs) due to their nature of work and working environment. OBJECTIVE: To identify the prevalence of WMSDs and associated risk factors and to conduct real-time testing to evaluate Whole Body Vibration (WBV) and Hand-Arm Vibration (HAV) in buses based on the ISO standards to assess the vibrations levels at different speeds. METHODS: Participants in this study were 370 full-time male bus drivers from the north and south zones of 13 depots of Bengaluru Metropolitan Transport Corporation (BMTC), Bengaluru, south India. Information regarding WMSDs symptoms during the previous 7 days and 12 months were collected by Modified Nordic Musculoskeletal Questionnaire (MNMQ). WBV and HAV testing was performed and vibration levels were compared with ISO-2631-1 (1997) and ISO-5349-1-2001 standards. It was found that 68.7% of participants reported WMSDs. RESULTS: Several individuals and work-related factors were found to be statistically significant with WMSDs. From the Gini impurity measure, vibration and road types (Asphalt pavement and Rough road) were considered as vital risk factors associated with WMSDs. CONCLUSION: From the WBV and HAV evaluations, it was found that for buses on asphalt pavement at > 60 km/h, the vibration level was higher compared to a lower speed. The vibration level exceeded the Exposure Action Value (EAV) on rough roads at all speeds (20km/h, 40km/h and 60km/h) and in several situations considered based on assumptions the vibration level exceeded the Exposure Limiting Value (ELV).