Is it possible to strain sternum? have pain when pressing on left side sternum. had chest x-rays recently and everything is normal. dr said i have slight scoliosis. i normally crack my back by twisting upper body quickly. if thats relevant

Basics: Your ribs articulate (have a joint) with the sternum that is mostly cartilage in youth & middle age. It is possible to have localized irritation/inflammation at any of the sternum points where the ribs join it. These often arise after a simple viral illness or from trauma. Anti-inflammatories may help with discomfort. It is not worth much thought & should pass in time.