Ergonomic evaluation of commercially available operator lifts for farmers with disabilities

Individuals in the agricultural population who are impacted by mobility restrictions resulting from strokes, arthritis, amputations, back injuries, and other medical conditions are capable of safely returning to work through the appropriate application of assistive or rehabilitation technology. The purpose of this study was to develop and administer a systems approach for evaluating ergonomic and safety issues related to the application of commercially available operator lifts used on agricultural and other offroad machinery to provide a means for operators with restricted mobility to gain access to the operator\u27s station. Input from operator lift users, objective analysis and a panel of experts were used to gain a clearer perspective of commercially available operator lift systems. Unstable seats, awkward transfers and the need for fall arresting devices were identified as concerns through on-site visits of operator lift users. Objective analysis methods, including the use of an operator lift users\u27 questionnaire, were used to identify key issues, such as usability of the operator lift controllers and using the operator lifts in emergency situations, which needed to be addressed. An expert panel used lift evaluation tools to identify problems with installation, wiring and troubleshooting related to operator lift systems. Based upon feedback from 60 operator lift users, spinal cord injuries were reported by 42 (75%) of the users. Forty-three (76%) of the users had full use of their upper arms. Only nine (17%) of the lift users were able to access the same piece of machinery after their injury and before they had a lift. Eight (16%) of the 49 individuals that purchased a commercially manufactured lift reported a minor injury or near injury while using their lift. Similarly, one (14%) of the seven individuals that had a locally manufactured or homemade lift reported a minor injury while using their lift. Even though it appeared that the level of safety was the same for commercially manufactured and locally fabricated lifts, commercially manufactured lifts appeared to have fewer hazards associated with them. The findings from this study can be used to justify the safety and applicability of operator lifts in agriculture, aid in the design and fabrication of future operator lifts, and develop an industrial standard on the design, fabrication and testing of operator lifts for use on off-road equipment