An evaluation of manual materials handling in highway construction work

Construction work is generally described as strenuous but few systematic characterizations of physical load have been published to date. PATH (Posture, Activities, Tools and Handling) is an ergonomic assessment method used to measure the frequency of exposure las a proportion of observations) to manual materials handling (MMH) activities and other exposures for construction and other non-routinized work. Observations of loads handled, body postures, tools and materials handled and hand grasps are available for further description of MMH activities. PATH has been used to characterize manual handling by iron workers tin concrete reinforcement work), carpenters tin form construction) and laborers tin the construction of utilities pits) during highway construction operations. Of these trades, the iron workers were the most frequently observed in heavy MMH activities (involving at least 13.5 kg), and they often lifted in twisted or laterally bent trunk postures. Heavy MMH activities by laborers most frequently involved the handling of boards used to construct the pit walls. Little heavy MMH (at least 22.7 kg) was observed in the carpentry tasks. NIMH requirements varied greatly among tasks within each construction operation, demonstrating the importance of a task-based assessment of MMH exposures. Analysis of subsets of data on the iron workers and the carpenters showed that, in some cases, task and worker were important sources of variance. For almost all variables, the error term (interpreted primarily as day-to-day differences in exposure) was the largest source of variance. Therefore,an evaluation of multiple workers over long time periods for specific tasks is necessary for a reliable characterization of MMH requirements and other ergonomic exposures in highway construction work.