Back pain, is it due to my athletic training or not?

Patient: Dear doctor,I am 15 years old and I frequently get back pain between my spine and shoulder blade, its roughly 12cm down from my shoulder line and 4cm from my spine, it is incredibly sore to the touch. Pain also occurs mainly when i sit down. I attend Mixed Martial arts classes regularly and have now stopped as it seems to worsen after each class; could this be an injury sustained through training? It only begins to hurt when i either sit down or touch the area (which is roughly the size of a drinks can)

Doctor: