Ergonomic Assessment of Floor-based and Overhead Lifts

Manual full-body vertical lifts of patients have high risk for developing musculoskeletal disorders. Two primary types of battery-powered lift assist devices are available for these tasks: floor-based and overhead-mounted devices. Studies suggest that the operation of floor-based devices may require excessive pushing and pulling forces and that overhead-mounted devices are safer and require lower operating forces. This study evaluated required operating hand forces and resulting biomechanical spinal loading for overhead-mounted lifts versus floor-based lifts across various floor surfaces and patient weight conditions. We did not examine differences in how operators performed the tasks, but rather focused on differences in required operating forces and estimated biomechanical loads across various exposure conditions for a typical operator. Findings show that the floor-based lifts exceeded recommended exposure limits for pushing and pulling for many of the floor/weight conditions and that the overhead-mounted lifts did not. As expected, forces and spinal loads were greater for nonlinoleum floor surfaces compared with linoleum floors. Based on these findings, it is suggested that overhead-mounted devices be used whenever possible, particularly in instances where carpeted floors would be encountered.