What could be the cause of pain on the ribs?

Chest pain: Could be a problem with skin, nerves, muscle, shoulder, lung, heart, or stomach. See your doctor for a more thorough history, physical exam and further evaluation. Maybe you pulled a muscle in your chest.

How long: How long has it been? Rib fracture pain can be seen for months after injury. I tell my patients that with or without rib surgery, they can expect pain from the ribs for around 3 months. If the pain lasts longer than that, you might want to be evaluated - there may be injury from the fracture to the intercostal nerve below the rib, and these can be painful and permanent.