When i cough or sneeze my right part of my back hurts what could it be?

Muscle strain/spasm: Coughing and sneezing requires an intense and rapid muscle contractions--all of the muscles surrounding your chest wall and around and under the scapula areas. Often the muscle around or under the scapulaes are "strained" from sudden and forceful coughing/sneezing, thus can cause some pain after inflammation kicked in..Good strecthing, motrin/aleve may help. If worse, contact your doc. Good luck.