After having several heart attacks and being obese I decide to buy a treadmill but when I run I get splitting shin pain how do I fix this?

You need new or . Different shoes that will help properly line up your foot, ankle and knees in order not to strain this area. My best advice is to go to a specialty store, specializing in marathon/ long distance running gear. Have your feet evaluated, then purchase the brand of running shoe that fits your feet properly, then get on that treadmill and start slow!