Bettany-Saltikov J, Cole L
Teesside University, Middlesbrough, UK.
Stud Health Technol Inform. 2012;176:117-21.
Students at school and university settings have been shown to carry heavy loads in a variety of pack systems. Both type and mode of load carriage have been shown to cause significant postural adaptations that can lead to injuries in the shoulder, arms, hands and back. Whilst backpacks have been well researched, there is a paucity of literature on the effects of frontpacks, shoulder bags and hand-held bags on 3D posture and back shape.
The objective of this study was to evaluate the effect of carrying three different types of bag (shoulder, front and handheld), each containing a load of 15% body weight.
The Integrated Shape Imaging System 2 (ISIS 2) was used to evaluate 3 D back shape and posture.
The study involved twenty-five university students. A repeated measures design was used to record the effects of four conditions using no load (reference), a frontpack, a shoulder bag and a handheld bag. Measurements with ISIS 2 were taken 5 minutes post loading. All of the conditions were randomised in an attempt to offset any order effects. Results showed an increase in extension and lumber lordosis angles for the front bag (P<0.001) and an increase in flexion and reduced lumber lordosis in the shoulder and hand held bags (p<0.05). Kyphosis curves were also significantly increased in the hand held bag (p<0.006). Right unilateral load carriage also demonstrated the greatest right volumetric asymmetry.
Bilateral front carriage as supported by previous literature produces a symmetrical shift away from the load. Unilateral carriage however produces an asymmetrical deviation away from the load which results in significant postural deviations and adaptations.
Frontbags may be more suitable for load carriage within the young adult student population as they produce a symmetrical postural deviation in one plane in response to load. The shoulder and handheld bags produce postural deviations in all planes which may cause adverse stress and strain on spinal structures and ultimately lead to pain and progressive postural scoliosis.
研究表明，中小学及大学阶段的学生使用各种背包系统背负沉重负荷。负荷的类型和背负方式均已显示会导致显著的姿势适应性变化，进而可能引发肩部、手臂、手部和背部受伤。虽然背包已得到充分研究，但关于前背包、肩包和手提包对三维姿势和背部形态影响的文献却很匮乏。
本研究的目的是评估背负三种不同类型的包（肩包、前背包和手提包），每种包负重为体重的15%时所产生的影响。
使用集成形状成像系统2（ISIS 2）评估三维背部形态和姿势。
该研究涉及25名大学生。采用重复测量设计记录四种情况（无负荷（参考）、前背包、肩包和手提包）的影响。在负重5分钟后使用ISIS 2进行测量。所有情况均随机安排，以试图抵消任何顺序效应。结果显示，前背包导致伸展和腰椎前凸角度增加（P<0.001），肩包和手提包导致屈曲增加且腰椎前凸减小（P<0.05）。手提包的驼背曲线也显著增加（P<0.006）。右侧单侧负重还表现出最大的右侧体积不对称。
如先前文献所支持的，双侧前背负会产生远离负荷的对称偏移。然而，单侧背负会产生远离负荷的不对称偏差，从而导致显著的姿势偏差和适应性变化。
对于年轻成年学生群体，前背包可能更适合负重，因为它们在负重时会在一个平面内产生对称的姿势偏差。肩包和手提包会在所有平面产生姿势偏差，这可能会对脊柱结构造成不利的压力和应变，并最终导致疼痛和进行性姿势性脊柱侧弯。
