College students who use heavier backpacks are significantly more likely to suffer low-back pain, compared with their peers who use lighter backpacks. These findings were published in the Journal of Manipulative and Physiological Therapeutics.
As part of the analysis 465 students at Colorado State University completed online surveys. Findings showed that “a 25% increase in the odds of annual low back pain for each 4-kg increase in the estimated usual backpack weight was observed after adjusting for sex, smoking, reporting frequently feeling overwhelmed, and body mass index … .”
However, “there was no evidence of an increased association of annual low back pain with carrying a backpack weight greater than 10% of the students’ body weight compared with those carrying less … .”
“The results of this study suggest that increasing reported backpack weight is associated with increased prevalence of annual low back pain,” conclude the study’s authors. “However, these results do not provide evidence to support the recommendation that the backpack weight necessarily be less than 10% of body weight.”
JMPT – July, 2010;33:432-37.