Evaluation of five steering input devices in terms of muscle activity, upper body kinematics and steering performance during heavy machine simulator driving

Abstract

Work related upper body musculoskeletal symptoms and disorders constitute a major problem for operators of heavy machinery. Steering input devices mediate risk factors of upper body musculoskeletal disorders. Little research has been conducted to compare the multiple commercially available steering input devices in a multi-faceted approach. The present study evaluated five commonly used steering input devices (conventional steering wheel, fast steering wheel, miniature steering wheel, first-order joystick and second-order joystick) in terms of muscle activity, upper body kinematics and steering performance during heavy machine simulator driving. Fifteen healthy males novice to operation of heavy machinery completed five laps on a simulated track with each steering input device. Results showed a generally lower muscle activity when using the joysticks. The conventional and fast steering wheel increased mean wrist and shoulder flexion/extension angles and participants spent more time in wrist flexion/extension angles corresponding to moderate and poor comfort levels. An increased elbow protonation angle was found for the three steering wheels compared to the joysticks. The conventional steering wheel showed slowest track completion time and was subjectively ranked worst. The first-order joystick was ranked highest but also showed the highest amount of steering reversal rates, posing a risk of increased repetitiveness. Overall, the second-order joystick is considered superior ergonomically compared to the other steering input devices evaluated. However, all evaluated steering input devices exceeded muscle activity and/or joint angle recommendations.Relevance to the industry: Compared to steering wheels, joystick steering showed reduced muscular activity and less awkward joint postures, suggesting a reduced risk of developing musculoskeletal disorders in the long term. However, the results warrant efforts to further develop joystick steering resulting in a reduction of exposure level beyond the existing solutions.