hi i am 15 and the last 2 days during gymnastics my middle upper chest has hurt. It only hurts when i am doing like a back walk over or front walk over and during the beginning of practice. It did not bother me on any of the other events and it does not bother me at home. Also i have asthma it is not bad i do not use a inhaler usually and it only affects me during practice. what could be causing this pain? it seems to occur when i bend over.