I remember the incident well… I was lining up for class after a wet school lunch hour, when one of the school ‘nerds’, shuffling along on his way to class (no doubt delayed by a busy lunch hour fulfilling his library assistant duties), rounded a corner, slipped on a wet patch of floor and lost control. His backpack, seemingly twice his weight, spun him round, throwing him onto his backside, the momentum skittling him into a galvanised rubbish bin that couldn’t have been more strategically placed. Like a bowling ball smashing into pins, the rubbish bin and its content of uneaten lunches, packed lovingly by hundreds of mothers, exploded and the poor guy was left lying there, dazed and humiliated. As fast as it had happened, he picked himself (and his pride) up and hurried off down the corridor toward his classroom. The whole class was in hysterics – we had had our entertainment for the afternoon. Hopefully, he packed his bag a little lighter next time.
However, the reality of heavy school bags really isn’t that funny. The US Consumer Product Safety Commission reports that backpack-related injuries sent more than 7,000 people to the accident and emergency department in 2001 alone.
A study published last year showed that there is a dramatic increase in the prevalence of back pain during adolescence, from less than 10 per cent during pre-teenage years to up to 50 per cent in 15 to 16-year-olds. It found that heavy backpacks carried by adolescents strongly contributed to the development of back pain. Those most at risk were of the female gender and those with a larger body mass index (the overweight).
The average school backpack tends to be 17 per cent of the child’s body weight. This is equivalent to a 60kg adult carrying 10kg, or two five-litre bottles of water. On top of this, over one-third of students carried more than 30 per cent of their body weight at least once a week. That’s four five-litre bottles of water!
The American Chiropractic Association and American Academy of Pediatrics both recommend limiting the backpack’s weight to no more than 10 per cent of the child’s body weight and urge the use of ergonomically correct backpacks.
The effects of carrying heavy backpacks may also pose a serious threat to your child’s spinal development and future overall health. Carrying a backpack with one strap results in a change in gait and posture, with lateral (sideways) spinal bending and shoulder elevation. There is evidence to show that the longer the load remains, the longer it takes for a curvature or deformity of the spine to correct itself. What is not known yet is how much of this stress it takes before some deformity remains.
Not only does carrying a heavy backpack put a large strain on their developing bodies, it also increases the chance of falls and injuries. Students carrying 25 per cent of their body weight on their backs demonstrate problems with balance while performing normal activities, such as climbing stairs, which, in turn, increases their risk of falls. In contrast, packs weighing 15 per cent of the student’s body weight enable them to maintain their balance reasonably well. Those carrying five per cent of their body weight are shown to be much more effective in maintaining balance while performing everyday tasks.
As a parent, there are numerous things you can do to ensure your child is not overloaded, wears his/her backpack correctly and avoids undue strain on his/her developing body:
1. Make sure that the weight of the backpack does not exceed more than 10 per cent of your child’s body weight. See what your child needs to carry and what he/she can leave either at home or at school. Maybe he/she can alternate who takes a particular book with a classmate, so he/she only carries that particular book half as often.
2. Avoid using backpacks or sports bags that have only one strap.
3. Ensure that your child wears both straps on his/her shoulders and the load is well balanced. The heaviest items should be packed so that they are closest to the body, ideally positioned mid-back. Lighter items can be further away.
4. Adjust the straps so the backpack doesn’t hang more than 10cm below the waist-line. The backpack should sit close to the body and not be pulling away at the shoulders (it could be the wrong size for your child).
5. A good backpack should have a waist strap. This should be used and fastened snugly. The purpose of this strap is to distribute the load between the shoulders and hips, so that around 80 per cent of the load is carried on the hips (where your body’s natural centre of gravity is).
6. Have your child examined regularly by a chiropractor, so that any potential spinal or postural problems can be addressed and corrected.
If it’s time to get a new school bag:
• Take your child, together with what would normally be packed in the bag, so you can check that it is comfortable when loaded.
• The bag should fit close to your child’s body. Bags come in different sizes, just like shoes, so find one that fits. The straps should hug the backs of the shoulders, not pull away. With the shoulder and waist straps fastened, there should be almost no lateral movement of the bag. You can test this by gently pulling down on the (loaded) backpack and, at the same time pull, the backpack from side to side. Your child should sway with the movement and the bag should not come free.
• Bigger is not necessarily better. The larger the backpack, the more your child will carry, and the heavier it will be.
• You tend to get what you pay for, but shop around. Outdoor stores generally have a good range of durable bags and the staff should be trained to find a bag that fits your child.
The backpack I purchased in the middle of high school cost a small fortune at the time, but it has survived all I’ve thrown at it, along with a lifetime at university. It’s a little worse for wear but I still have it today, many years on.
Dr. Mark Lane has clinics in Portimão and Almancil. He can be contacted on 916 666 480 or by email at [email protected]
