Ergonomic Assessment of Plastic Syringe Manufacturing Processes

Plastic industry workers are often exposed to repetitive tasks and awkward postures due to mass production, increasing their risk of ergonomic-related injuries. This study aimed to assess these risks in a real plastic syringe injection molding factory, focusing on the injection molding workstation as a case study. Various ergonomic assessment tools were used, including the Cornell Musculoskeletal Disorder Questionnaire, Ovako Working Posture Analysis System (OWAS), Rapid Upper Limb Assessment (RULA), and Rapid Entire Body Assessment (REBA), and Jack Siemens software for posture simulation. The results revealed that workers are commonly experienced pain in the lower back, neck, and shoulders. After implementing ergonomic modifications to the workstation, the assessment tools indicated a significant reduction in risk levels: compression forces on the lower back decreased by 30%, shear forces by 49%, and the percentage of time spent in risky joint angles per work cycle decreased by 3% for the neck, 23% for the back, 3% for the shoulder, 5% for the wrist, and 9% for the elbow. These findings highlight the importance of ergonomic redesign in improving worker health and reducing occupational hazards.