Jennifer Liaw, a senior principal physiotherapist at the Department of Physiotherapy, Singapore General Hospital (SGH) shares tips on choosing the right school bag for your child.
Ergonomic school bags are generally backpacks marketed to parents who are concerned that their child is carrying a heavy load. By knowing what design elements they should look out for, parents will be equipped to decide whether they should get a normal school bag or pay a premium for a bag marketed as “ergonomic”.
Choosing the right school bag for your child
Weight of school bag
The general guideline from Health Promotion Board (HPB) is for children to carry no more than 15 per cent of their bodyweight. In practice, that would generally mean no more than 3.5kg to 5kg for a child in the first few years of school.
Heavy backpacks representing 30 per cent of the body weight and above may modify posture and gait. A child may develop poor posture or a slouching habit as he or she copes with a heavy and poorly positioned bag. This increases the risk of neck and back pain.
Style of school bag
School bags fall into two general categories: double strap bags (backpacks) or single strap bags (sling bags). As the child gets stronger and more used to the weight of a school bag, carrying up to 20 per cent of the bodyweight across both shoulders, or 10 per cent across one shoulder (sling bag), should not cause any harm.
Carrying more than the recommended load on one shoulder exerts imbalanced forces on the spinal and trunk structures of children who are still growing. Unilateral loading may cause spinal compressions, muscle aches and pain.
A backpack with two shoulder straps, properly fitted, is designed to distribute weight across both shoulders. However, wearing a backpack often leads to awkward twisting of the torso as the child attempts to lift the bag and wear both straps. Putting on and taking off the bag repeatedly may cause muscle fatigue and strain especially when the load is heavy.
9 design elements of a good backpack
Backpack fitted to the torso length. The backpack should rest between the C7 vertebrae which is the first and most prominent bone on the spine when you bend your neck forward, and the top of the hip bone (iliac crest). Rest your hands on your hip with the thumbs on the back. The place where the thumbs rest is where you want the bag to rest. If the bag is longer than the torso, there would not be an ergonomic fit. The torso length determines whether you need a small, medium or large backpack.
Wide, padded straps. Thin straps can cut into the shoulders, making the bag uncomfortable to carry.
Sternum belt. The sternum belt will hold the shoulder straps in place.
Compartments instead of a single top loading opening. Compartments help to organise the contents and hold the items snugly against the torso.
Pockets and magnetic flaps. It makes access to bottles and pencil cases much easier. No need to worry about closing the bag.
Waist belt. It distributes the load across the hips if the load is heavy and adds extra stability, reducing the stress on the shoulders and neck.
Padded and ventilated backrest. This would make carrying the bag more comfortable.
Waterproofing. This is to prevent rain or sweaty backs from ruining the items.
Compression straps. Use the compression straps to keep the load snug and compact against the back.
Are ergonomic school bags worth the price tag?
Most bags advertised as “ergonomic school bags” would have some of the features mentioned above. A simple bag costs about $80 while the models with more features can fetch between $140 and $200. Look out for ergonomic features in regular bags as well. Keep in mind that the more features a bag has, the more it will weigh.
For a primary one child, a lightweight canvas single sling bag may be more manageable than a comparatively heavier backpack, provided the load is within the recommended limit. The child would avoid carrying excess weight due to the backpack itself and would not need to struggle with putting on and taking off two straps.
The sling bag should be carried across the chest with the load positioned on the back, close to the body, not dangling off by the hip, to decrease the risk of backache. If the child is able to comfortably use a backpack and wear it properly, consider using it if the load is at the upper limit.