Effect of load distribution of the backpack- a design study

Backpack or school bag weight carried by children has raised concerns in worldwide countries over recent decades. School going children face a major problem because of the heavy weight they carry to school everyday as it leads to many problems such as a bent posture and decreased work efficiency. The prescribed weight to be carried by children has been determined to be 10-15% of their body weight; however literature shows that the majority of them carry up to 30% of their body weight. Design changes were introduced in a standard backpack to see how it would facilitate load distribution over the upper torso such that the load is not concentrated on the trunk alone. Subjects were asked to carry out trials with 0% body weight, 15% body weight with a standard backpack and 15% body weight with the modified backpack with arm straps. ECG data using Biopac MP150 was collected and the results between the three trials were compared. The results show loads of 15% of body weight or above significantly increased the amplitude of the R wave which was lower in case of carrying 15% of body weight with the arm strap. Thus the modified backpack has a potential for efficient load carriage.