春節(jié)即將來臨，許多人已經(jīng)踏上回家路程，相信不少人都是大包小包回家。你有沒有想過，從第一次背書包上學(xué)到現(xiàn)在，你換過多少種背法？雙肩、單肩、掛在小臂上、拿在手里，或者干脆把東西塞進(jìn)褲袋？
(資料圖)
不同的拿包方式，包的重量，帶子的長(zhǎng)短、角度和物品擺放，都影響身體姿勢(shì)和費(fèi)力程度。多年的錯(cuò)誤拿包姿勢(shì)，可能是你肩、頸、腰背痛的原因，也可能把身體姿態(tài)帶跑偏。以下是健康人的拿包指南，相關(guān)疾病患者請(qǐng)遵從醫(yī)生建議。
本來站得挺直，背上包就歪了丨作者供圖
包的總重量越輕越好，盡量不要超過體重的10%，至多20%。相對(duì)瘦弱的人，更需要減輕負(fù)擔(dān)[1-3]。
因?yàn)椴还茉趺茨?，包的重量越大身體就越歪。不僅頭前伸、身體前傾的角度變大，脊椎中間的椎間盤也會(huì)被壓得更扁。這些會(huì)增加脊柱周圍組織及下肢關(guān)節(jié)的壓力，導(dǎo)致各處疼痛以及關(guān)節(jié)的損傷[4-6]。
背包變重，頭前伸，身體前傾丨作者供圖
如果要帶的東西實(shí)在太重，就改用箱子裝。同等重量下，拉或推箱子時(shí)身體姿態(tài)比背包好，所以舒服也省力，尤其是需要站著久等的情況（箱子拉桿夠長(zhǎng)，站直能拉?。?。但路途中坡道及臺(tái)階多的時(shí)候，背包比拎箱子更輕松[7-9]。
拉箱子時(shí)身體姿態(tài)更好丨作者供圖
除了重量，背包的方式對(duì)身體影響最大。有人嫌棄雙肩背包丑，但兩側(cè)對(duì)稱的姿勢(shì)比單肩背健康。
單側(cè)拿時(shí)，偏在一邊的包會(huì)把身體拉偏，造成脊柱側(cè)彎及高低肩，腿部受力也不均衡，容易出現(xiàn)頭、肩頸、腰背及下肢關(guān)節(jié)疼痛。同樣重量的包，改為雙肩背可以明顯減少這些不舒服[4, 10-15]。
雙肩背包身體左右對(duì)稱，單肩背包身體歪斜丨作者供圖
常有人為了拿東西方便或安全，把雙肩背包掛在胸前。這樣不容易彎腰駝背，但比背在后面時(shí)身體后仰更多，腰部壓力更大。背包站立時(shí)間長(zhǎng)的時(shí)候，可以前后交替，但走動(dòng)的時(shí)候，還是背在身后更舒服[11, 16-20]。
背在后面身體前傾，包在前面身體后傾丨作者供圖
背包時(shí)的肩痛，常與肩帶有關(guān)。寬且有填充物的軟帶比較舒服。兩個(gè)肩帶之間的距離不能太大，角度最好在48°~60°，間距或角度過大會(huì)增加肩部壓力，可能引起肩痛[19, 21, 22]。
左圖肩帶距離及角度合適，右圖角度過大丨pixabay, pxfuel
調(diào)整肩帶時(shí)，首先保證兩側(cè)長(zhǎng)度一致，然后根據(jù)身高調(diào)整肩帶長(zhǎng)短，使包的中心在腰部。如果肩帶過短，把包背在上背部，可能肩頸難受、呼吸不順暢。肩帶過長(zhǎng)，包放在臀部的話，腰容易不舒服，而且走路時(shí)包會(huì)晃動(dòng)，更加費(fèi)力[2, 3, 19-24]。
左圖背包太高，中圖適中，右圖稍低丨作者供圖
如果背包有腰帶，系緊它能將肩壓力減輕近三分之一，并讓背包在步行中更加穩(wěn)定[2, 25]。
系緊腰帶更輕松丨nps.gov
偏要單側(cè)拿包的話，背在肩上更好。因?yàn)榘鼟煸谇氨刍蚰迷谑掷飼r(shí)，人會(huì)不自覺地更駝背、身體晃動(dòng)更多，這樣不舒服也走不穩(wěn)[11, 26]。
單肩背包時(shí)，可以把肩帶調(diào)長(zhǎng)，斜跨著背，這樣比背在一側(cè)好[14]。如果不能斜跨，就把肩帶調(diào)短些，這樣走起路來身體左右兩側(cè)更平衡[27]。
斜跨比單側(cè)背更好丨作者供圖
有時(shí)出門只帶手機(jī)和鑰匙就夠了，這時(shí)不拿包，全部放在衣褲口袋也可以。但帶更重東西的時(shí)候，還是背包省力些[6, 28]。運(yùn)動(dòng)的時(shí)候，把手機(jī)放在腰包，也比臂包更舒服。
往包里裝東西的時(shí)候，需要格外注意重物的位置。首先，盡量把最重的物品固定在離身體最近的地方，比如把電腦插進(jìn)貼近背部的分隔里，不要讓它滑到包的后面。只要包里物品的重心前移5厘米，肩部壓力就會(huì)明顯降低[2, 17, 21]。
電腦隨意放置，重心偏后，固定在分隔中更省力丨作者供圖
其次是重物的高度，站立不動(dòng)或走平路時(shí)，把重物放在背包里偏上的位置比較省力。但上下坡道或臺(tái)階時(shí)，把重的東西放在包里的中下位置，可以走得更穩(wěn)[28-30]。
從超市買了很多東西，放不進(jìn)背包時(shí)，盡量分成兩個(gè)袋子裝，把重量均分到兩只手上。
如果只用右手提，走路時(shí)左腿受力就會(huì)明顯大于右腿，關(guān)節(jié)容易受到損傷，上下臺(tái)階時(shí)影響更大。另外，同樣重量的東西，單手拎時(shí)脊柱所受壓力大于雙手，椎間盤更易受損[13]。
兩只手提購(gòu)物袋，比單手好丨作者供圖
最后，無論怎樣拿包，都記得保持核心穩(wěn)定，把身體擺正。
穩(wěn)住核心，擺正身體丨作者供圖
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關(guān)鍵詞： 雙肩背包 兩側(cè)對(duì)稱的 彎腰駝背
