An ergonomic assessment of an operating engineer: a pilot study of excavator use.
Appl Occup Environ Hyg 1997 Jan; 12(1):23-27
An ergonomic analysis of heavy construction equipment operation was performed. A 54 year old male operating engineer operating an excavator at a highway reconstruction project in Massachusetts was followed for one working day. The different tasks he performed during the day, digging trenches, laying concrete pipe in the trenches, and backfilling the trenches, were analyzed using time and motion techniques. The subject completed questionnaires to rate perceived exertion (RPE), work conditions, and job stress and satisfaction several times during the day. Heart rate was monitored using a portable heart rate monitor. The operator spent considerable time operating hand levers which required fine repetitive motions of both arms. Having to hold the levers in a particular position placed static loads on the shoulders. He also spent extended amounts of time in seated posture; the seat did not provide lumbar support nor did it counter the effects of static lumbar loading. The operator spent 18% of the workday on breaks and 27% in pauses between tasks. Heart rates while performing the tasks increased only slightly above baseline. The RPEs indicated the work load to be very light throughout most of the day. The time weighted average noise exposure of the operator was 77 decibels-A (dBA). When the excavator was moving, noise exposures increased to 92dBA. Job stress ratings in conjunction with the heart rate data indicated that the subject's job was associated with low levels of stress, despite high psychological demands. The author concludes that the most important ergonomic problems faced by operating engineers are repetitive hand/arm motions and awkward static postures. Recommendations include redesigning the control layout to reduce the repetitive hand/arm movements and static loading on the shoulders, and measuring forces required to operate the controls.
NIOSH-Publication; NIOSH-Grant; Musculoskeletal-system-disorders; Ergonomics; Work-analysis; Construction-equipment; Repetitive-work; Equipment-operators; Psychophysiology; Construction-workers; Heart-rate
Cooperative Agreement; Construction
Applied Occupational and Environmental Hygiene
Center to Protect Workers' Rights