Patient C came to the clinic complaining of pain in her left calf. Her calf is swollen and hurts even when at rest. Before coming into the clinic, Patient C had been running track. All of a sudden, she felt tightness and pain in the back of her calf. The X-ray shows no breaks or fractures, and an MRI shows no nerve damage. Based on Patient C’s history, which diagnosis is most logical?

What facts support your diagnosis?