Good day! I am in the Navy, and shin splints almost stopped my career!
You must take magnesium! Sometimes we have an over-accumulation of calcium which causes the bones to harden to a point where they can snap from calcification. Start with 50mg once a day. This will make you feel very relaxed - this is normal! Give it a few weeks but the results will worth it. And you must also stretch your shins by training your legs. Get on your knees and sit "Japaneese" style by leaning back as far as you can go. It will get your shins good and stretched. It was a life saver for me.
Oh, and take Apple Cider Vinegar (ACV) 2x a day!