Ergonomic Design and Evaluation of an Electric Nail Removal Device

Nowadays, musculoskeletal disorders resulting from working with improper hand tools have been known as one of the major concerns in various industries. In the current study, an ergonomic nail removal device was proposed to evaluate the intervention for nail removal activity in the woodworking and carpentry industry. Eleven male workers, who were actively involved in nail removing activity, were asked to perform nailing activity by removing nails driven into the bottom and top of the door as the base points for painting the doors using both the nail removal device and the traditional plier. The Rapid Entire Body Assessment (REBA) and Strain Index (SI) techniques were used to characterize the level of risk. Moreover, nailing task duration and task repetition were measured as important criteria in manual works. According to the SI and REBA risk indices, the final scores for the designed device were estimated at 2 (low-risk level) and 1.5 (safe), respectively, while these values for the traditional pliers were 12 (high-risk level) and 15 (dangerous). Moreover, using the designed electric nail removal device led to a reduction in the repetition and duration of the task. Overall, the application of the proposed device in the nail removal tasks has shown risk indices below the critical thresholds in terms of correcting work posture and reducing strains imposed on workers' upper limbs.