Use of field-based motion capture to augment observational data in ergonomic assessment of aircraft maintenance

摘要

A dramatically increasing trend in the population of aircraft painters with permanent physical limitations was identified among participants in the return-to-work program at a large aircraft maintenance facility. The increase came primarily from painters who had used a full-depth mechanical sanding depainting process. A detailed ergonomic assessment of the process was begun to elicit details of the range and types of risks faced by painters in that shop, and determine what types of mitigation might be utilized to minimize the prevalence of injury. Shoulder injuries represent the biggest area of ergonomic risk for painters. Cervical problems, hand/wrist problems, and lumbar problems make up the majority of the remainder of injuries. The extent, duration, and complexity of the risks involved in the depaint process required more data than the typical observational and psychophysical assessment tools could provide. Inertial motion capture and tool force instrumentation was implemented in combination with the typical ergonomic methods to provide more details as to the biomechanical sources of risk and how this varies throughout the depainting process. The results indicate surprisingly high normal forces on the palm sander, with rapid muscle fatigue and frequent postural substitution evident during overhead sanding. The long duration of this overhead activity, in combination with the evidence of fatigue, implicates the development of risky scapulo-humeral kinematics and end-of-range glenohumeral motion in the etiology of shoulder and cervical injuries. A mix of management and engineering strategies for mitigation resulted from the analysis.