Backpacks Weight and Position Effect on Musculoskeletal Symptoms in Elementary School Ages

Introduction: Low back pain is common in school ages with reported incidence of 24%-37%^1,2 Backpack load is a significant risk factor for developing backache. A general guideline of 10-15% body weight (BW) is accepted to estimate the maximal mass allowed for backpacks.

Purpose: The purpose of the current study was to evaluate the weight of school bags in the elementary school students and to investigate whether the position of the bag affects the risk for developing musculoskeletal symptoms.

Materials and Methods: A prospective cross-sectional study was conducted, and a convenience sample of four community schools was included. Inclusion criteria: 1) students in first to sixth grade 2) ability to carry backpack. Students with neurologic or musculoskeletal disorders were excluded. Students’ body weight was determined with and without their backpacks. The distances between the shoulders level line and superior edge of the bag was measured and defined as Shoulder Distance (SD), and the distances between the thoracic spine and superior edge of the bag was measured and defined as Back Distance (BD). The students were asked to mark on a visual Analog Scale (VAS) to rate the intensity of their shoulders, neck, back and knees pain.

Results: Following our criteria 516 students were included in our study. The backpack load was lower than 15% of the BW in 23% of the cases. However, 58% of the students had backpack load of 15-25% of their BW and in 19% the load was more than 25%. Students with increased BW and SD had significantly increased VAS score for backache (p <0.05).

Conclusions: Our date show that 77& of elementary school students have increased Backpack weights and this requires immediate intervention. In addition, an ergonomic design of the backpack to eliminate the SD may reduce the risk for developing musculoskeletal symptoms.