Lower back pain (LBP) due to the whole-body vibration exposure is a common health problem among heavy equipment operators in the construction industry. This study utilizes a system dynamics modelling approach to develop a dynamics model of the LBP prevention index in Sri Lankan construction industry to assess the current level of LBP prevention maturity and plan for long-term improvement. The developed dynamics model consists of five key factors, namely (1) personal, (2) organizational, (3) equipment, (4) job-related and (5) social-context, together with their 17 associated items. Both secondary and primary data are used for the model development. Secondary data are extracted from several literature reviews, while primary data are obtained from interviews and observations on sites. The simulation results show that the LBP prevention index reaches the highest maturity level, which is level 5, at 39 years. Personal, job-related and social-context are key factors that enhance the LBP prevention index in the long-term. A construction company should focus more on human aspects than equipment acquisition, as this helps to achieve higher levels of maturity in the long-term. A construction company can use the developed dynamics model to plan for an effective LBP prevention program to enhance the LBP prevention index in the long-term.