Brackley Heather M, Stevenson Joan M, Selinger Jessica C
School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.
Work. 2009;32(3):351-60. doi: 10.3233/WOR-2009-0833.
Parents, educators and researchers have expressed concern about the long term impacts of children carrying excessive loads in their backpacks on a daily basis. Although many researchers have investigated appropriate weight limits for children's packs, little research has been conducted on the design of children's backpacks. The purpose of this study was to evaluate the changes in children's trunk forward lean (TFL), cranio-vertebral angle (CVA) and spinal lordosis angle (LA) that occurred with high, medium and low load locations during standing and walking. Ten-year-old children (n = 15) completed a repeated measures designed study while carrying 15% of each child's body weight in a typical backpack with only shoulder straps. A special instrumented backpack (IBP) was designed that allowed the weight to be placed in the proper location and continuously measure changes in spinal curvature. TFL and CVA postures were captured on digital video at five intervals including: standing without a backpack prior to a 1000 m walk; standing with a backpack at the beginning and end of a 1000 m walk; and walking with a backpack at the beginning and end of a 1000 m walk. Results indicated that significant changes occurred in TFL and CVA when the backpack was loaded to 15% body weight. The low load placement in the backpack produced fewer changes in CVA from the initial standing baseline measure than the high and mid placements. When all measures were assessed collectively, there were fewer changes in LA in the low load placement. These findings indicate that future backpack designs should place loads lower on the spine in order to minimize children's postural adaptations.
家长、教育工作者和研究人员对儿童每天背着过重的书包所产生的长期影响表示担忧。尽管许多研究人员已经对儿童书包的合适重量限制进行了调查，但关于儿童书包设计的研究却很少。本研究的目的是评估在站立和行走过程中，高、中、低负荷位置放置书包时儿童躯干前倾（TFL）、颅椎角（CVA）和脊柱前凸角（LA）的变化。10岁儿童（n = 15）在背着一个仅带有肩带的典型书包、重量为各自体重15%的情况下，完成了一项重复测量设计研究。设计了一种特殊的带仪器背包（IBP），它能将重量放置在合适位置并持续测量脊柱弯曲度的变化。在五个时间点通过数字视频捕捉TFL和CVA姿势，包括：1000米步行前不背书包站立时；1000米步行开始和结束时背书包站立；以及1000米步行开始和结束时背书包行走。结果表明，当书包重量达到体重的15%时，TFL和CVA发生了显著变化。与高负荷和中负荷放置相比，低负荷放置在书包中时，CVA相对于初始站立基线测量的变化较少。当综合评估所有测量结果时，低负荷放置时LA的变化较少。这些发现表明，未来书包设计应将负荷放置在脊柱更低的位置，以尽量减少儿童的姿势适应性变化。
