The Prevalence of Low Back Pain and Its Relation With Backpack Weight Among Iranian Students

Purpose: Several studies have reported that musculoskeletal disorders and discomforts experienced by children and adolescent students are closely related to the weight of bags or backpacks carried by them. Since students are at growth and spinal development age, attention to the pressures on their bodies is important. These pressures can cause musculoskeletal problems and various growth disorders. This study aimed to investigate the prevalence of Low Back Pain (LBP) and its relation with the backpack weight among students. Methods: This cross-sectional study with non-experimental design was conducted on 2000 elementary and secondary school students (1000 boys and 1000 girls) who were randomly selected from schools in 5 regions of Tehran City, Iran. Students with LBP for more than 6 weeks during the study or during the last 3 years at 3 intervals that each lasted for 1 week or more were listed in a group with LBP and others in a group with no LBP (the control group). The weight of their bags or backpacks was measured over a week, and the average was recorded as the weight of carrying load. The intensity of pain was measured using the Visual Analogue Scale. To examine the prevalence of LBP in students, absolute and relative frequency distribution tests, and for examining the correlation between LBP and weight of backpacks, Independent t test were employed. Furthermore, the Pearson correlation coefficient was used to determine the relationship between the weight of backpacks and the intensity of pain. In addition, logistic regression analysis was used to assess the predictability of LBP based on the backpack weight. Results: Based on the results, 26% of students had LBP (29.6% girls, and 21.8% boys). Mean±SD scores of LBP in girl and boy students were reported as 3.4±2.8 and 2.3±5.8, respectively. According to t test results, there was a significant difference between the two groups in terms of backpack weight both in girls and boys (P<0.05). The Pearson correlation test results showed a significant correlation between the weight of backpacks and intensity of LBP among boys (r=0.26, P=0.007) and girls (r=0.31, P<0.001). Furthermore, results of logistic regression analysis indicated that the variable of backpack weight can predict LBP (B=0.52, P=0.01). Conclusion: The weight of the bags or backpacks carried by children and adolescent students has a significant relationship with the prevalence and intensity of LBP in this age group.