【英语时差8,16】走路为什么摆臂？-下

But although it happens passively, arm swinging plays an important role in making your stride more efficient. It does this by counterbalancing your torso and hips¹ and keeping them from twisting and bobbing too much. Holding your arms still against your sides while walking requires twelve percent more energy than if your arms are allowed to swing naturally. Forcing your arms to swing in sync with the leg on the same side of your body uses a whopping twenty-six percent more energy than normal walking. Even when walkers had their arms strapped² to their sides, so no muscle control was required to keep them still, they used seven percent more energy than when their arms could swing freely. This suggests that arm swinging is not just a passive byproduct of walking, but actually makes walking easier.

1 hips   

abbr.high impact polystyrene 高冲击强度聚苯乙烯，耐冲性聚苯乙烯n.臀部( hip的名词复数 )；[建筑学]屋脊；臀围（尺寸）；臀部…的

参考例句：

• She stood with her hands on her hips. 她双手叉腰站着。
• They wiggled their hips to the sound of pop music. 他们随着流行音乐的声音摇晃着臀部。 来自《简明英汉词典》

2 strapped   

adj.用皮带捆住的，用皮带装饰的；身无分文的；缺钱；手头紧v.用皮带捆扎(strap的过去式和过去分词)；用皮带抽打；包扎；给…打绷带

参考例句：

• Make sure that the child is strapped tightly into the buggy. 一定要把孩子牢牢地拴在婴儿车上。 来自《简明英汉词典》
• The soldiers' great coats were strapped on their packs. 战士们的厚大衣扎捆在背包上。 来自《简明英汉词典》