Select bags, they must buy back the bags shoulders, and pay attention to bags of material, size, width of the strap. Dorsal shoulder bag does not recommend, in addition to the body s weight-bearing does not allow children on average, the future is also prone to back pain, spinal imbalance. Second, the material to light, mainly light, canvas, polyester fibers of these materials can be, leather is not recommended. As to the size, need to choose the proportion of children s height, length is about the child s shoulder to the hip joint, the width of the arm swing without prejudice basis. Do not install a lot of things in order, and buy a big bag, the child s spine will cause great pressure.

Strap proposed at least five centimeters wide, must be able to adjust the length, the best there is in the thick pad on the strap design. Bags behind, that is, the back side posted the best but also the thick pad design, in addition to comfort, but also can help absorb the children running, the bags hit the impact body.

Some bags will be in the position of the waist belt plus an auxiliary, is a very good design, this way you can share back and shoulders about 50-70% of the negative weight. In addition, there are many small bag the best sandwich, or separate design, so that when they can carry the weight more evenly spread.

选择书包的时候，一定要买双肩背的书包，并且注意书包的材质、大小、背带的宽度等。不建议购买单肩侧背书包，除了会让小孩身体的负重不平均，日后还容易产生背部酸痛、脊骨不平衡的问题。其次，材质以轻巧、轻便为主，帆布、聚酯纤维这些材质都可以，皮革就不建议了。至于体积的大小，需要根据小孩的身高比例来选择，长度大约是孩子的肩膀到髋关节，宽度以不妨碍手臂的摆动为基准。千万不要为了装很多东西，而买一个很大的书包，对小孩的脊椎会造成很大的压力。

背带建议最少要有五公分宽，一定要可以调整长度，最好在背带上就有加厚垫的设计。书包的后面，也就是贴背的那一面，最好也有厚垫的设计，除了舒适之外，也可以帮助吸收小孩跑步时，书包撞击到身体的冲击力。

有些书包在腰部的位置会加一条辅助带，是非常好的设计，如此一来可以分担背部和肩膀大约百分之五十到七十的负重量。另外，书包最好有很多的小夹层或是分隔设计，这样在背负时也可以让书包的重量比较平均分布。