閃腰 is because the muscles on back are not strong.

來源: 於 2012-02-14 06:43:53 [博客] [舊帖] [給我悄悄話] 本文已被閱讀：次

That is what I learned from Physical Therapist. And with some excise designed to strengthen the muscles, I am almost 100% recovered from herniated disk.