on (one's) feet

1. Literally, standing upright. We've been on our feet for over an hour—let's find somewhere to sit for a while.

2. In a healthy or stable condition, usually after a period of illness or misfortune. I was out with the flu for a week, but I'm back on my feet now. After bringing in some new management, the business is finally on its feet again.

3. Quickly and extemporaneously. This job requires you to think on your feet and make decisions at the drop of a hat.

on your ˈfeet

1 standing up: Working in a restaurant means that you’re on your feet all day long.
2 (of a business, etc.) in a strong position again after a period of difficulty, uncertainty, etc: Only our party’s policies will really get the country on its feet again. ♢ The company seems to be back on its feet now.