School backpack weights: a survey of students in Ghana, Guatemala and the USA.

Cross-sectional studies were conducted in conveniently selected schools in Ghana, Guatemala, and the USA to quantify and compare the percentage of body weight carried by students in their backpacks as well as assess parental knowledge of the backpack weights and contents. Mean backpack weights varied significantly by country and increased significantly with increasing student grade. In the USA, girls significantly carried heavier backpacks (p <.0001). The backpack loads represented an average of 7.7% (95% CI = 7.4-8.0), 9.7% (95% CI = 9.2-10.2), and 9.4% (95% CI = 9.1-9.8) of student body weights in Ghana, Guatemala, and the USA, respectively. No student in Ghana carried a wheeled backpack in contrast to 6% and 2.8%, respectively, in Guatemala and the USA. In Ghana, 4.1 and 73.6% of parents were reported to be aware of their children's backpack weights and contents, respectively, compared to 21.9 and 57.5% in Guatemala, and 7.7 and 55.3% in the USA. Backpack loads respresent a significant percentage of the body weights of students in all three countries. The vast majority of parents are unaware of their child's backpack weight.