Workstation design based on ergonomics in animal feed packing process

Abstract

The intention of this study to design the probability optimized sewing sack's workstation based on ergonomics for productivity improvement and decreasing musculoskeletal disorders. The physical dimensions of two workers were using to design the new workstation. The physical dimensions are (1) sitting height, (2) mid shoulder height sitting, (3) shoulder breadth, (4) knee height, (5) popliteal height, (6) hip breadth and (7) buttock-knee length. The 5 th percentile of buttock knee length sitting (51 cm), the 50 th percentile of mid shoulder height sitting (62 cm) and the 95 th percentile of popliteal height (43 cm) and hip breadth (45 cm) applied to design the workstation for sewing sack's operator and the others used to adjust the components of this workstation. The risk assessment by RULA before and after using the probability optimized workstation were 7 and 7 scores and REBA scores were 11 and 5, respectively. Body discomfort-abnormal index was used to assess muscle fatigue of operators before adjustment workstation found that neck muscles, arm muscles area, muscles on the back and the lower back muscles fatigue. Therefore, the extension and flexion exercise was applied to relief musculoskeletal stresses. The workers exercised 15 minutes before the beginning and the end of work for 5 days. After that, the capability of flexion and extension muscles' workers were increasing in 3 muscles (arm, leg, and back muscles).