Abstract

Manual material handling (MMH) task contributes to a large percentage of musculoskeletal disorder cases and injuries in occupational settings. Musculoskeletal disorders (MSD) often involve strains and sprains to the lower back, shoulders, and upper limbs. They can result in exposure of workers to risk factors that eventually turn into costly injuries and lost productivity. Several studies have shown that effective ergonomic interventions can decrease the physical demands of manual material handling tasks thus lowering the occurrence and severity of MSD and occupational injuries. In order to control the nature and severity of these injuries in MMH task, this paper aims to design an ergonomic trolley to assist the tasks of workers. The researchers were able to come up with a design of a 6wheel trolley that has a capacity to carry a load of 100-kg weight. It has a tri-star hub that rotates to overcome uneven floors and stairs that will enable to single handedly transport load safely. In addition, the handle height and handle diameter of trolley was based on anthropometric dimensions of Filipino workers namely standing elbow height and hand grip diameter in order to match the design of trolley to the anthropometric requirements of Filipino users. The 3D design of the trolley was made using Fusion 360 software. After which, the trolley was fabricated using plasma cutter and lathe machine. It was then tested on three different pushing positions (rough surface, elevated surface and staircase) in order to compute for its mechanical advantage. The researchers then analyzed and computed for the actual force that must be applied comparing it to the load that can be transported by six-wheeled trolley. The findings of the study have proved that the newly designed trolley will be able to reduce the risks in manual pushing and pulling operations involving whole-body effort as evidenced by the result RAPP tool analysis.