A unique study conducted by researchers at University of California on the backpack load of a number of middle school children in the U.S. reveals that it is much higher than that required for comfort and safety. It has even warned about the possibility of back pain as a result of the excessive pressure over the shoulders.
Alarmingly, more than 7000 school-going children present in the emergency room for treatment of injuries related to backpacks or book bags according to a survey conducted by Consumer Product Safety Commission.
In order to minimise the side effects and avoid chronic back pain, the research committee has come up with four suggestions. Backpacks should be positioned high on the back, backpack straps should be over both shoulders, weight in the backpacks should be minimized, and backpacks should have wide straps.
The researchers studied the distribution of weight from school back over shoulders and with specific reference to back pain among 10 school going children, aged 13. The participants were fitted with sensors attached to shoulder straps. The children were monitored while carrying standard, identical backpacks accounting for 10, 20 and 30% of their body weight in succession.
Increase in weight of the backpack was directly associated to pain levels. More specifically, backpack weights of 20% of the body weight were sufficient enough to have adverse effects on the skin and local blood flow. Children commonly carry backpack loads equal to 22 percent of their body weight.