Assessing the readiness of assembly line workers to adopt the upright posture

Based on a biomechanical model, an upright body posture has an important contribution to the prevention of musculoskeletal disorders and back pain. This study was conducted to determine the relationship between the constructs of theory of planned behavior and the stage of readiness for maintaining correct body posture among the assembly line. In this cross-sectional study, a total of 264 workers from Pars Electric and Kachiran factories with an average age of 35 years and selected by convenient sampling method were investigated in 2009. Data were collected using a questionnaire with appropriate psychometric properties of 5 parts including the demographic information, attitude, perceived behavior control, subjective norms, and intention as well as a staging algorithm for maintaining an upright posture during a 6-month period. The results of analysis of variance (ANOVA) showed that all selected variables shared a significant variance with the stage of readiness and that the discrimination between the stages by the selected variables was successful. Structural equation modeling was indicative of a direct relationship between the intention and the stage of readiness. Also, the subjective norms & perceived behavior control which showed to have direct relationships with intention exerted their effects on stage of readiness through intention mediation (P<0.05). Perceived behavior control, subjective norms, and intention are beneficial to understand the individual differences in stage of readiness for maintaining upright body posture and considering the subjective norms and managerial supportive network is essential to promote safe behavior.