I used to be a bigtime heel striker, had shin splints like crazy, basic training and AIT was torture on my shins. For a time I thought I had stress fractures. After I graduated from all my training I investigated POSE and Chi-Running and all that. I tried it the way they suggested and have kind of drifted towards midfoot striking for anything that isn't a sprint. It's become more natural in the last year or 2 but it's been quite an effort. I still hate running but at least I don't feel like my lower legs are splitting!
"And for crying out loud. Don't go into the pain cave. I can't stress this enough. Your Totem Animal won't be in there to help you. You'll be on your own. The Pain Cave is for cowards.
Pain is your companion, don't go hide from it."