Hey all!! Well I am more motivated. I've been running this week in a running machine. I alternated compeltely barefoot running (9 minutes) and min shoes running (6 minutes). I'm very good, and no one injuries, only blisters getting keratinized. I run 180-200 steps/minute. Just running relaxed and not obssesed (?) with the way I run, My organism is cleverer than I am haha.
Today I run 25 minutes aprox, 4 km, with min shoes. the only trouble I had was one blister that is cured yet but, as I told, it need to be keratinized.
No back pain, for the time being.
=)