Can drinking lesser water or drink while standing cause pain in knee or feet bones? how much water one must take in a day?

Hydrate: It is good to drink lots of water throughout the day. I believe 64 oz a day is still the recommended amount. However, not being hydrated enough is not a likely cause of foot and knee pain.

Standing drink ok: Drinking standing should not be problem and certainly should not case knee or foot pain. 32 oz of water is average. Some people require more and other less.