出门必备，科学背包指南

春节即将来临，许多人已经踏上回家路程，相信不少人都是大包小包回家。你有没有想过，从第一次背书包上学到现在，你换过多少种背法？双肩、单肩、挂在小臂上、拿在手里，或者干脆把东西塞进裤袋？

不同的拿包方式，包的重量，带子的长短、角度和物品摆放，都影响身体姿势和费力程度。多年的错误拿包姿势，可能是你肩、颈、腰背痛的原因，也可能把身体姿态带跑偏。以下是健康人的拿包指南，相关疾病患者请遵从医生建议。

本来站得挺直，背上包就歪了丨作者供图

(资料图片)

包的总重量越轻越好，尽量不要超过体重的10%，至多20%。相对瘦弱的人，更需要减轻负担[1-3]。

因为不管怎么拿，包的重量越大身体就越歪。不仅头前伸、身体前倾的角度变大，脊椎中间的椎间盘也会被压得更扁。这些会增加脊柱周围组织及下肢关节的压力，导致各处疼痛以及关节的损伤[4-6]。

背包变重，头前伸，身体前倾丨作者供图

如果要带的东西实在太重，就改用箱子装。同等重量下，拉或推箱子时身体姿态比背包好，所以舒服也省力，尤其是需要站着久等的情况（箱子拉杆够长，站直能拉住）。但路途中坡道及台阶多的时候，背包比拎箱子更轻松[7-9]。

拉箱子时身体姿态更好丨作者供图

除了重量，背包的方式对身体影响最大。有人嫌弃双肩背包丑，但两侧对称的姿势比单肩背健康。

单侧拿时，偏在一边的包会把身体拉偏，造成脊柱侧弯及高低肩，腿部受力也不均衡，容易出现头、肩颈、腰背及下肢关节疼痛。同样重量的包，改为双肩背可以明显减少这些不舒服[4, 10-15]。

双肩背包身体左右对称，单肩背包身体歪斜丨作者供图

常有人为了拿东西方便或安全，把双肩背包挂在胸前。这样不容易弯腰驼背，但比背在后面时身体后仰更多，腰部压力更大。背包站立时间长的时候，可以前后交替，但走动的时候，还是背在身后更舒服[11, 16-20]。

背在后面身体前倾，包在前面身体后倾丨作者供图

背包时的肩痛，常与肩带有关。宽且有填充物的软带比较舒服。两个肩带之间的距离不能太大，角度最好在48°~60°，间距或角度过大会增加肩部压力，可能引起肩痛[19, 21, 22]。

左图肩带距离及角度合适，右图角度过大丨pixabay, pxfuel

调整肩带时，首先保证两侧长度一致，然后根据身高调整肩带长短，使包的中心在腰部。如果肩带过短，把包背在上背部，可能肩颈难受、呼吸不顺畅。肩带过长，包放在臀部的话，腰容易不舒服，而且走路时包会晃动，更加费力[2, 3, 19-24]。

左图背包太高，中图适中，右图稍低丨作者供图

如果背包有腰带，系紧它能将肩压力减轻近三分之一，并让背包在步行中更加稳定[2, 25]。

系紧腰带更轻松丨nps.gov

偏要单侧拿包的话，背在肩上更好。因为包挂在前臂或拿在手里时，人会不自觉地更驼背、身体晃动更多，这样不舒服也走不稳[11, 26]。

单肩背包时，可以把肩带调长，斜跨着背，这样比背在一侧好[14]。如果不能斜跨，就把肩带调短些，这样走起路来身体左右两侧更平衡[27]。

斜跨比单侧背更好丨作者供图

有时出门只带手机和钥匙就够了，这时不拿包，全部放在衣裤口袋也可以。但带更重东西的时候，还是背包省力些[6, 28]。运动的时候，把手机放在腰包，也比臂包更舒服。

往包里装东西的时候，需要格外注意重物的位置。首先，尽量把最重的物品固定在离身体最近的地方，比如把电脑插进贴近背部的分隔里，不要让它滑到包的后面。只要包里物品的重心前移5厘米，肩部压力就会明显降低[2, 17, 21]。

电脑随意放置，重心偏后，固定在分隔中更省力丨作者供图

其次是重物的高度，站立不动或走平路时，把重物放在背包里偏上的位置比较省力。但上下坡道或台阶时，把重的东西放在包里的中下位置，可以走得更稳[28-30]。

从超市买了很多东西，放不进背包时，尽量分成两个袋子装，把重量均分到两只手上。

如果只用右手提，走路时左腿受力就会明显大于右腿，关节容易受到损伤，上下台阶时影响更大。另外，同样重量的东西，单手拎时脊柱所受压力大于双手，椎间盘更易受损[13]。

两只手提购物袋，比单手好丨作者供图

最后，无论怎样拿包，都记得保持核心稳定，把身体摆正。

稳住核心，摆正身体丨作者供图

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本文来自微信公众号“果壳”（ID:Guokr42），作者：代天医，编辑：odette，36氪经授权发布。