Understanding the Effects of Selected Backpack Loads Carried for Certain Durations on Peak Forces of Walking Gait in School-Going Boys

Background. Backpacks are commonly used by students to carry their school items. However, increasing backpack loads can lead to negative effects on health and posture, particularly through changes in gait dynamics. Peak forces are a critical variable in understanding gait mechanics, which is significantly impacted by carrying loads. Therefore, it is crucial to investigate the changes in peak forces with varying (increasing) backpack loads and the durations of carrying. Objectives. The study aimed to examine the effect of various backpack loads, carried for different durations, on the forces at first and second peaks of the left and right foot during a walking gait cycle in school-going boys. Materials and methods. The subjects (n = 85) between the age of 10 to 12 years, were randomly selected from Delhi NCR. The force at first and second peaks was measured using a ZebrisInc pressure platform supported by Win FDM-S software (Germany). Five backpack load conditions were analysed, namely, B1 = backpack load of 0 % of body weight (no additional weight in the backpack); B2 = backpack load of 8% of body weight; B3 = backpack load of 12 % of body weight; B4 = backpack load of 16 % of body weight; and B5 = backpack load of 20 % of body weight, at five following recording time, T1 = recording at zero minute of walking; T2 = recording at fifth minute of walking; T3 = recording at tenth minute of walking; T4 = recording at fifteenth minute of walking; T5 = recording at twentieth minute of walking. Statistical analyses included an assessment of the mean, standard deviation, coefficient of variation, and t-ratio. The significance level for the t-test was 0.05. Results. The results indicated that increasing backpack loads led to higher peak forces at both the first and second peaks of the gait cycle. The right foot exhibited elevated forces at the first peak, while the left foot showed dominance at the second peak. Furthermore, prolonged load carriage was also found to increase peak forces. A paired sample t-test revealed significant differences between the first and second peaks, with a mean difference of −14.402 N (p = 0.002) for the first peak and 4.860 N (p = 0.001) for the second peak. Conclusion. The study concluded that higher backpack loads significantly increased the mean of peak forces in walking gait, which may result in postural imbalances and gait asymmetry. These findings suggest a need for regulating backpack loads to prevent potential musculoskeletal issues in children.