Children require less gait kinematic adaptations to pull a trolley than to carry a backpack

To transport school materials, trolleys have been proposed for children as an alternative to carrying a backpack. However, there is limited evidence comparing the adaptations associated with carrying school trolley versus backpack. This study compared the effects of carrying a backpack and pulling a trolley on gait kinematics in children. Fifty-three students were evaluated. Children walked at self-selected speeds across a walkway with no bag (control), carrying a backpack with the 15% of child́s body weight (%BW) and pulling a trolley with the same load. Spatiotemporal gait parameters and 3D kinematics of lower extremities and thorax were computed. No significant differences were obtained in spatiotemporal parameters between pulling a trolley and control. Carrying a backpack resulted in larger kinematics gait alterations than pulling the trolley compared to control. In conclusion, pulling a school trolley (15%BW) was more similar to not carrying a bag than carrying a backpack of the same load during level walking.