Why my back hurts when i breath deep ? and it is also hurt when i move body suddenly.

Muscles..: It seems that for some reason your muscles are suffering a spasm or have been hurt somehow. Signs of pain triggered by movement or expansion of your thoracic cage when you take a deep breath( which stretches your muscles as a result) are consistent with this. Ice the area for 15 mins 3 times a day and if not allergic take anti inflammatory meds( like ibuprofen). If worse or not better see your dr.