Comparison of the posture of school children carrying backpacks versus pulling them on trolleys

Objective: To investigate whether there is a difference in the posture of schoolchildren walking with a backpack versus pulling a trolley. Design: Comparative, controlled, pilot trial. Setting: “Grundschule Fallersleben” – primary school in Germany. Subjects: Thirty-four school children between 6 and 8 years of age. Methods: Initially, neutral posture was measured in a standing position. All children were then asked to walk a predetermined route without intervention for approximately seven minutes. This was followed by walking the same route with either a backpack (n = 19) or trolley (n = 15). Deviations from neutral of the thoracic and lumbar spine (flexion, extension, lateral flexion and rotation) from the final 30 seconds of the imaging sequences were taken and analysed. Results: Compared to unburdened walking, walking with a backpack led to a statistically significant (p ≤ 0.05) increase in thoracic extension (3.91°, 95% CI = 3.35 to 4.46) and right lumbar lateral flexion (2.29°, 95% CI = -3.41 to -1.18), and a statistically significant decrease of lumbar flexion (2.2°, 95% CI = 0.34 to 4.06). In contrast, walking with a trolley increased extension (1.4°, 95% CI = 0.72 to 2.08), right lateral flexion (1.24°, 95% CI = -1.91 to -0.57) and right rotation (3.09°, 95% CI = -3.85 to -2.32) of the thoracic spine, and a statistically significant increase in left rotation (3.57°, 95% CI = 2.58 to 4.55) of the lumbar spine. Comparing the backpack and trolley groups showed to a statistically significant (p ≤ 0.05) increase in thoracic extension and right lumbar lateral flexion in the backpack group. Posture during trolley pulling was characterized by a statistically significant (p ≤ 0.05) increase in right thoracic and left lumbar rotation. Conclusion: Participants adopted asymmetric postures during walking with a backpack and pulling a trolley. However, the trolley group was characterised by spinal rotation which possibly adds an extra source of stress. This suggests that school children should use backpacks rather than trolleys when the weight is within recommended limits