The working postures of material handling operators in milk production industry contibute to the musculoskeletal disorders (MSDs) particularly in lower back region of their body. The original posture used in this task resulted in excessive compression (4250 N) and shear forces (5650 N) on the lower back, far exceeding NIOSH (National Institute for Occupational Safety and Health) recommended limits, indicating a high risk of injury. In response, workers were analyzed using simulation tools, which identified the most stressful operations. A new working posture was introduced, adjusting the work height during packet loading, which significantly reduced the compression force to 1890 N and the shear force to 720N, both well below NIOSH's safe limits. This ergonomic intervention not only lowered the physical strain on workers but also demonstrated the potential to create a safer working environment by minimizing the risk of lower back injuries. The study highlights the critical role of ergonomic adjustments in manual labor to protect workers from MSDs, improve workplace safety, and potentially enhance productivity. Future research could further explore the long-term benefits of these changes and their application to other industries with similar ergonomic challenges.

KEYWORDS: Musculoskeletal disorders, NIOSH, Workplace safety, JACK software.