Forces Loaded on the Back of Manual Material Handling Tasks' Workers of Food Industries in Malard Using"3D Static Strength Prediction Program”

Manual Material Handling tasks can cause fatigue in the short term and increase physical workload and musculoskeletal injuries in the long term. The present study was conducted to determine the amount of forces entered to the lower back in workers with manual material handling tasks. This descriptive-analytic study was conducted on 100 workers in food industries in Malard city in 2017. The Nordic questionnaire was used to determine the frequency of musculoskeletal disorders. The 3DSSPP was also applied to determine the amount of forces entered to the lower back of manual material handling tasks workers. Data analysis was conducted using SPSS (version 23) we found that 24percent of workers had discomfort in at least one of their nine musculoskeletal muscles. The results of 3DSSPP showed that 30 and 34 percent of the compressive forces entered into L5/S1 and L4/L5 discs, respectively. In addition, the shearing force loaded on the L5/S1 disc was also found to be higher than the permissible limit eight percent of the participants. No significant relationship was found between the frequency of musculoskeletal disorders and the amount of compressive and shear forces entered to the lower back of workers. Based on NIOSH recommended limits, the amount of compressive and shear forces entered to the lower back in 3DSSPP showed that in 30 percent of manual lifting load tasks, the risk of injury to the lower back was moderate and this risk was low in 70 percent of tasks