A 29 year old male presents with extreme burning and cramping pain upon exertion in the lower limbs. The patient is a competitive marathon runnerand recently ran the New York marathon despite the pain. The patient reports that the pain coincides with the start of physical activity. When the pain was first noticed, it subsided almsot immediately after the completion of physical activity. Over time, the pain has become more acute annd now it takes some time after the cessation of activity for the pain to subside. The patient also reports that recently numbness and and extreme weakness of the calf will result after sustained physical activity.