我的身体变得僵硬，感觉自己好像是混凝土做的，那么牢固，那么坚不可摧。

My body was stiff though, I felt like I was made of concrete, so solid and almost indestructible.

youdao

如果越过了这些界限，美国人的身体会明显变得僵硬，他的态度也会变得冷漠。

When those boundaries are crossed, an American's body will visibly stiffen and his manner will become cool and aloof.

youdao