Kinetics analysis on gait termination for children with backpacks / 医用生物力学

ABSTRACT

Objective To understand kinetics characteristics of gait termination for children with backpacks， and compare the difference between planned gait termination (PGT) and unplanned gait termination (UPGT) as well as effects of backpack carrying by children at the moment of gait termination. Methods Twelve boys (age (9.85±1.34) years old, height (140.89±11.57) cm, weight (34.96±9.62) kg) were recruited in this study. The gait termination scene in real life was simulated in the lab by the subjects who were required to carry different backpacks, while the parameters of ground reaction force and center of pressure (COP) during PGT and UPGT were recorded by two 3D force plates. Results There were significant differences in the peak ground reaction force curve between gait termination and normal walking. Meanwhile the peak ground reaction force and COP shifting during PGT and UPGT were both significantly larger than those during normal walking， and the values were increased with the increase of backpack load. The maximum ground reaction force and COP shifting were found during UPGT while the subject was carrying backpack equal to 15% of the body weight (15% BW). Conclusions The change of ground reaction force was useful for gait termination，but children will suffer much more impact force during both PGT and UPGT, and make the control on postural balance more difficult, which could be dangerous with the increase of backpack load. It is advised that children should lighten their backpack loads, which will be helpful to prevent accidental injuries during suddenly external disturbance.