Moreover, even though humans have been upright for millions of years, our feet and back continue to struggle with bipedal posture and cannot easily withstand repeated strain imposed by oversize limbs.

而且，就算人类已经直立行走已经几百万年了，我们的脚和背部继续对抗着巨大的压力，这些压力来源于双足直立的姿势和巨大的肢体。