With school bells sounding yesterday for the first time this academic year, medical authorities warned parents about excessively heavy schoolbags which in certain cases may even cause the disfigurement of their children. Andreas Constantopoulos, president of the Greek Pediatric Society, said that pupils’ schoolbags should not weigh more than 10 percent of the child carrying the gear. With primary school children weighing on average between 22 to 35 kilos, the weight of the bag should be between 2.5 and 3.5 kilos. However, research shows that children are often found lugging a bag around every day that weighs between 4 to 7 kilos. The excessive weight, along with incorrect positioning of the bag on the shoulder, can weigh on the spinal cord, cause pain and be responsible for temporary disfigurement of the body, according to Constantopoulos.