ache

我的下背部有些疼痛。

I've got an ___ache in my lower back.

因为一整天坐在书桌前，他的背开始疼了。

His back began to ___ache from sitting at the desk all day.

骑马一小时后，你的肌肉真的会酸痛。

After an hour of horseback riding, your muscles can really ___ache.