Is swelling in the feet common a day after shoulder surgery in a healthy individal?

Probably. Most likely yes. After a surgical procedure - especially requiring anesthesia (being put to sleep) - the IV fluids that are given are not quite in the right compartment of the body yet. Therefore, some swelling can be normal. Massive swelling that is asymmetric (is your other leg swollen?) can be a problem after surgery. Blood clots can occur in certain individuals that are post - operative.
Swelling. Yes - as dr lee stated the fluids given during surgery often take a while to be removed.