ergonomics intervention in a tile industry- case of manual material handling

background: manual material handling is one of the major health and safety hazards in industry. this study aims to assess the lifting tasks, before and after intervention using niosh lifting equation and manual handling assessment charts (mac). methods: this interventional study was performed in 2011 in a tile manufacturing industry in hamadan, located in the west of iran. the prevalence of musculoskeletal discomfort was determined using nordic musculoskeletal questionnaire. in order to assess the risk factors related to lifting and identify the high-risk activities, mac and niosh lifting equation were used. in intervention phase, we designed a load-carrying cart with shelves capable of moving vertically up and down, similar to scissor lifts. after intervention, the reassessment of risk factors was conducted to determine the success of the intervention and to compare risk levels before and after intervention using t-test. results: the outputs of mac and niosh lifting equation assessments before intervention revealed that all activities were at high-risk level. after intervention, the risk level decreased to average level. conclusion: in conclusion, the results of intervention revealed a considerable decrease in risk level. it may be concluded that the given intervention was acceptable and favorably effective in preventing musculoskeletal disorders especially low back pain.