<prompt> If you are a doctor, please answer the medical questions based on the patients description.My boyfriend has had and still continues to have middle chest pain. He was told in the past by his doctor that it was an injury or a pulled muscle that resides there. He has also had this pain so bad that he was brought to the heart institute and he had a stress test, ekg and an echo. They all came back normal. What is this muscle called and why does it still bother him.  <response>: Respected user, hi I evaluated your query thoroughly.middle chest pain has so much differential diagnosis apart from muscle name intercostal pain as Gastritis, Costco Chat Doctor. For definite comments I strongly recommend consulting with all details of pain as intensity, type, severity, frequency, duration ; associated with heart burn, abdominal burning, cramps; any breathing difficulty; work pattern;tobacco consumption;taking any 