14 DAY TRIAL // All the time children have carried their books and belongings in backpacks they have complained of shoulder and back pain.
A University of California, San Diego (UCSD) School of Medicine-led team found that how loads are distributed under backpack straps may help identify the source of shoulder and back pain in children.
Excessive pressure on the shoulder from too much backpack weight may be causing shoulder pain, and an uneven backpack load may contribute to low back pain.
The researchers hope their study will influence and improve future backpack design.
The research team, led by Principal Investigators Brandon Macias and Gita Murthy, studied five boys and five girls, aged 13 years old.
Each child's backpack was fitted with pressure sensors on the shoulder straps. The pressure sensors are the same type as those that measure standard blood pressure.
The children wore standard identical backpacks first carrying 10% of their body weight, then 20% and finally 30%. Macias says the group decided to study the backpack loads because there have been no studies connecting physiological pain and backpack loading.
With each weight level the children reported increased perceived pain levels. Surface pressures measured by the investigators were higher than the pressure threshold to obstruct normal skin and muscle blood flow.
"The concern of heavy backpacks and back and shoulder pain to parents is not new. However, the objective data that we have published is new and important. The more objective data that the public has, the more educated they become, and perhaps more inclined to change the way children carry backpack," Murthy states.
The research team hopes that parents will help their children avoid using heavy backpacks for prolonged periods and prevent backpack pain and related injuries.
The study concludes that the average backpack load that children are now carrying should be reduced.