When you carry a bag on your back, the load on the lower back increases significantly, for example, a study in the Clinical Biomechanics Journal compared the differences in forces in the lower back under varying backpack loads. The results showed:
- Walking with a load of 15% of body weight caused a 26.7% increase in the load of the lower back.
- Walking with a load 30% of body weight caused a massive 64% increase in the load on the lower back.
- They also noted that walking with a heavy bag caused a compensatory trunk flexion posture (bending or forward leaning posture).
What is the ideal weight of a school bag?
There is a little conjecture as to how much a bag should weigh. The Chiropractic Association of Australia suggests that children should limit the weight they carry in their bags to only 10% of their body weight. That’s only around 4-5kgs for a 40-50kg student. On the other hand, The American Academy of Orthopedic Surgeons recommend that the weight of a child’s backpack should be no more than 10-15% of a child’s weight. The American Physical Therapy Association suggests 15-20%. If you can limit your child’s school bag to as close to the 10% mark as possible, I think you are heading in the right direction.
Tips to help prevent problems associated with heavy school bags
The first step is to pick up your child’s bag and see how heavy it actually is and how it is packed, as this can make a difference. You can then see how their bag matches up to the following tips.
Tips on the ideal bag:
- A must is to have a bag with 2 padded shoulder straps. A single strap bag will only create imbalances.
- The bag should have a padded back.
- Ideally the bag should have a waist strap to help distribute the weight of the bag to the pelvis and not just hang off the shoulders.
- The bag should be no wider than the child’s shoulders.
- Ideally the bag shouldn’t hang below the waist.
Tips on packing and wearing the back pack:
- Make sure the bag is packed correctly so that heavier items are placed closer to the spine.
- Try to distribute the weight as evenly as possible.
- When wearing the bag, make sure they use both shoulder straps. Slinging the bag over one shoulder is not ideal.
- Adjust the straps so that the bag sits snuggly to the back and doesn’t hang below the waist. If your bag has a waist strap, make sure it used.
- When the bag is lifted make sure proper lifting techniques are used.
- Make sure your child is not having to lean forward to carry the bag. If they are, it is most likely too heavy for them.
When your child comes home from school, check out their bag and see how it fits with the tips above. If you need to, make changes to ensure minimal risk of problems in the future. If your child is having any problems or complaining of pain make sure you get them assessed by a chiropractor or health professional. Small changes made now can make significant changes in the future. We offer FREE spinal assessments of children, so if you have any questions or your child is complaining of a sore back, we may be able to help. Make sure you contact us and arrange a time for a spinal assessment. We are here to help.