Can stress cause painful knots all over your body-not just back and neck? (like arms and chest)

Yes: Stress can cause variety of symptoms, in a variety of body parts and systems. It is often the case that stress response for a given person is like his/her "signature": although it usually differs from person to person, an individual has a typical for him/her stress response. Learning your own unique way of how your body and mind respond to stress can help alleviate these symptoms better.