An expert talking about ergonomics
How much weight is a small back able to carry around? Quite a lot! It depends on how much a child has to carry and particularly how and how often the weight is carried. The stability of the back has also to do with the training of the muscles. A child that moves a lot and is sporty will have less complaints than a couch potato staying at home all day. How much weight should a school bag have at its maximum? Some studies show that carrying more than 10% of one’s own body weight increases the risk of backache in adolescence. Therefore, an elementary school child should not carry more than 2-4kg. Yet it is not the empty weight of the backpack that counts, but the filled backpack. The most important thing is the distribution of the weight. If there is too much weight on the shoulders, the child tries to compensate it. For example by bowing its back and this might stress the back in the long run. A broad hip belt has the ability to distribute up to one third of the weight to the stable pelvic area – the shoulders are relieved. Isn’t it harmful to the back when my child is running or jumping around and the school bag hits the back, respectively the spin? Depending on the weight and the acceleration several kilos will hit the child’s back. This is at least inconvenient. If it is also harmful has not been studied so far. But children will counteract by moving less. It seems to be reasonable to fix the bag or backpack in such a way that it will move less.
Melanie Gabriel is a qualified physiotherapist who has passed her Master of Science in 2006 at the Philipps-Universität Marburg. Since 2002 she is working as a freelance physiotherapist as well as a lecturer at the University Fresenius and the Philipps- Universität Marburg. In her daily work with children she combines theory and practice and is also acquainted with the needs of schoolchildren.