Why is My girlfriends back is hurting real bad?

My girlfriends back is killing her it tarted yesterday she said it just came out of no where and it felt like a jabbing pain everytime she moved and it went away so we were playing basketball and she had to stop because she was tierd and i told her to go lean against the pole and she did she said that she barely touched it and the pain was breathtaking she littarally fell on the ground she its only on her right side though under her ribs what could we do?