Ergonomic Risk Factors a Study of Heavy Earthmoving Machinery Operators Background Data of Operators & Equipment Evaluated in the Study

ALTHOUGH MANY STUDIES HAVE SHOWN an association between operating heavy construction equipment and symptoms of musculoskeletal disorders (MSDs), little research has been performed that systematically characterizes the exposure of operating engineers to ergonomic hazards. This study evaluated: 1) vibration at the seat/operator interface; 2) transmissibility of vibration in the Z-axis; 3) psy-chophysical ratings of vibration level and vibration discomfort; and 4) postural requirements of the job. Results indicate that the digging operation had higher levels of total weighted acceleration than high-or low-idling conditions. Transmissibility data showed that the seat amplified vibration, particularly in the lower frequencies. Seats demonstrated that they may not be sufficient in protecting operators from long-term effects of vibration exposure. High positive correlation was found among subjective ratings (vibration discomfort and vibration level), but moderate positive correlation was found between subjective ratings and quantitative vibration levels. Postural evaluations revealed that the operators were required to assume awkward postures of the neck, shoulder and trunk while performing their jobs. Work-related injuries and illnesses pose a continuing threat to the health and well-being of American workers. The construction industry has been historically recognized as having higher rates of fatality, injury and illness than other industries (McVittie 285+; BLS). In 1994, an estimated 218,800 lost-workday injuries were reported in the construction industry (BLS). Construction also had the second-highest incidence rate for sprains and strains. Although the industry has made progress since then, injuries and illnesses, including MSDs, continue to be cause for concern. Operating engineers (also known as hoisting and portable engineers) operate and maintain heavy construction equipment, such as cranes, bulldozers, front-end loaders, rollers, backhoes and graders; they may also work as surveyors or mechanics. This equipment is used to: 1) build roads, bridges, tunnels and dams; 2) construct buildings and power plants; 3) remove earth materials and grade earth surfaces , and to replace concrete, blacktop and other paving materials; and 4) construct drainage systems, pipelines and related tasks, such as blasting (Stern and Haring-Sweeney 51+). An estimated 487,000 operating engineers (55 percent union, 45 percent nonunion) are employed in the U.S. and Canada, most of whom are exposed to whole-body vibration, albeit in concert with other occupational risk factors. Past studies have shown that MSDs affect construction equipment operators due to awkward postures (e.g., static sitting), whole-body vibration, work intensity, high-resistance levers and repetitive motions (Kittusamy, et al; Buchholz, et al 23+). It is believed that reducing …