Evaluation of Spatio-Temporal Gait Symmetry during Unilateral and Bilateral Backpack Carrying with Different Weights Using VBT Algorithm

The purpose of the present study was to examine the effect of unilateral and bilateral backpack carrying with different weights on the spatio-temporal gait symmetry in healthy adults.

Totally, 17 healthy females with the mean age of 21.73 years volunteered to participate in the study. Participants completed carrying unilateral and bilateral backpack with loads of 0, 5, 10, and 15% of their body weight. Then, their gaits were assessed using a 3D motion analysis system with six cameras. Also, the spatio-temporal parameters of the gait and step time and step length symmetry indices were calculated using Velocity-Based Treadmill (VBT) algorithm and coding in MATLAB. Data were analyzed using paired sample t-test and repeated measures ANOVA (p<0.05).

The results of the present study showed that with increasing backpack weight, stance, swing and double support duration increased and the step length and cadence decreased. Evaluation of the symmetry index showed that the symmetry decreases with increasing load exerted to the body and leads to asymmetry of lower extremity. It was also found that unilateral backpack carrying affects the symmetry index more than bilateral backpack carrying; the difference when carrying backpack with 15% of the body weight was found to be significant.

According to the results obtained in the present study, it is recommended that to improve symmetry, the backpack weight should not exceed 10% of their body weight and backpack should be carried bilaterally.