Effectiveness of a Theory-Based Educational Intervention on Modifying Body Posture of Computer Users in Iran

Computer users are susceptible to musculoskeletal disorders. The association between musculoskeletal disorders especially low back pain and sitting posture in the occupational setting has been confirmed in available studies. The main aim of this study was to determine the effectiveness of an educational intervention on body posture modification and psychosocial mediating variables based on the Theory of Planned Behavior (TPB). In this quasi-experimental study، 75 computer users from Qazvin university of medical sciences who spent at least 20 hours per week at a VDT were selected to receive the ergonomic intervention، and the same number of students from Qazvin international university were assigned to a control group randomly. Both groups were evaluated at the beginning of the study and at a follow-up 3 and 6 months later. The following tools were used; the Rapid upper limp Assessment (RULA) method to assess upper-extremity work-related posture، self administrated questionnaire that evaluated TPB constructs and ergo – knowledge quiz. The tool’s internal consistency reliability، Cronbach alpha reliability coefficient، test–retest reliability، content and face validity were examined. The intervention included two program elements; theory-based brochure، and personalized preventive educational counseling. Data analyzed by χ2، independent t test، repeated measure ANOVA and Kruskal Wallis test. Total tools ’ psychometric value was acceptable. The intervention group had significantly higher scores than controls in ergo-knowledge، attitudes، perceived behavior control، intention، as well as nonneutral posture maintenance as goal behavior (P< 0. 05). At 3 and 6 months follow up، no significant differences were found between the two groups for subjective norms constructs. Intervention failed to improve RULA risk level to low and very low area (1، 2 level) and it only decreased the risk exposure to medium level. Our findings showed that the theory-based ergonomic interventions may improve work-related posture but this effect per se failed to decrease ergonomic risk factors to low level of risk exposure. The results suggest that preventive ergonomic activities would be more successful if educational intervention regarded as a part of multifaceted interventions that include at least two of the following aspects; analysis and elimination of risk factors، engineering and administrative controls.