Loading of the lumbar spine during backpack carriage

Abstract

Backpack carriage is significantly associated with a higher prevalence of low back pain. Elevated compression and shear forces in the lumbar intervertebral discs are known risk factors. A novel method of calculating the loads in the lumbar spine during backpack carriage is presented by combining physical and numerical modelling. The results revealed that to predict realistic lumbar compression forces, subject-specific lumbar curvature data were not necessary for loads up to 40 kg. In contrast, regarding shear forces, using subject-specific lumbar curvature data from upright MRI measurements as input for the rigid body model significantly altered lumbar joint force estimates.

Keywords:

• Low back pain
• backpack carriage
• lumbar compression
• lumbar shear
• lumbar curvature

Acknowledgment

We would like to thank the institute of radiology in Zürich-Altstetten, Switzerland for the technical support in the MRI measurements.