A bulging backpack may seem like a sign of a studious adolescent, but a bag loaded with too many textbooks can be an indicator of back, neck, knee and shoulder injuries to come. Each year, thousands of U.S. children are treated for book bag-related injuries, some worthy of a trip to the emergency room. The most common injuries are muscle strains of the neck, shoulder and back, says Abdurrahman Kandil, MD, an orthopedic surgeon. These burdensome bags are also responsible for some adolescent back pain, which can increase the likelihood of chronic back pain in adulthood. A 2017 study of 4,005 children between the ages of 8 and 13 found that 70 percent of subjects carried a bag that exceeded the 10 percent bag weight-to-body weight ratio and 32 percent of the sampled students experienced back pain. There are a number of reasons your child might experience pain or injury due to a book bag - maybe it is packed improperly, worn on one shoulder or just too heavy. Read on for more tips to help keep young ones safe on their way to and from school. Long-term problems with backpacks Back pain and injury in children can be the result of many factors, such as contact sports, poor posture or inactivity, but it may also be caused by carrying a book bag loaded with textbooks and school supplies between classes. Exceedingly heavy knapsacks cause more than a daily nuisance, and can lead to long-term problems. Backpack-related strains arent typically long-lasting, but children who lug heavy packs for a period of time may develop poor posture, which can linger for years to come, according to Kandil. A well-fitting backpack can help alleviate this particular problem, but its not the only risk associated with a heavy book bag. Expert-approved ways to prevent injury Backpack-related injuries arent inevitable, but preventing pain takes a bit of preparation. Buy the right book bag: Its never a bad time to purchase the proper pack, and when youre on the hunt, there are a few features to keep in mind. Backpacks should be lightweight and equipped with a cushioned back and two thick, padded straps. Sometimes we see numbness or tingling associated with very thin straps, Dr. Kandil says. This isnt uncommon if theres a lot of weight focused on a small area of a childs shoulder. Multiple compartments help distribute the weight in the bag, and Kandil recommends investing in a pack with a waist strap, which helps keep the backpack closer to the body and decreases the load on your childs back. Here are some other tips to avoid backpack-related injuries: 1. Pack it properly A lighter backpack is always better, but evenly distributing the weight decreases the amount of strain to the neck, shoulder and back muscles, says Kandil. Utilize all of the bags compartments and if your young one must transport heavy items, like bulky text books, position them in the middle of the bag, near the bottom. 2. Know when its too heavy Even if a book bag is packed to perfection, a heavy backpack can still be dangerous. Weight recommendations for your childs backpack vary between 5 to 20 percent of their body weight. The American Academy of Pediatrics puts a safe load between 10 and 20 percent of a childs total weight, while the American Chiropractic Association suggests no more than 5 to 10 percent. Its best to keep your childs knapsack as light as possible - use the bathroom scale as your guide. Clean it out weekly with your child to help prevent overloading. 3. Sport it just right Encourage your young one to use both shoulder straps and the waist buckle. Tighten the pack so the bottom of the bag sits at the waist. The general recommendation is not to have the lower part of the backpack hanging more than four centimeters below the waistline, Kandil says. He also notes the importance of safely picking up the pack by bending at the knees rather than the waist and using both hands. A rolling backpack may be no more effective at preventing injury, since many children improperly picking up these types of bags to travel up and down the stairs. Using rolling bags in a crowded hallway can also pose a tripping hazard. My general recommendation is to wear an appropriately sized, lightweight, well-padded backpack on two straps with a waist belt, Kandil concludes. The Medical Center of Aurora is a leader in healthcare. Click here to make an appointment with a pediatric doctor.