I've been having shin pain and lower back pain since I started running again post christmas. A little background; never been a natural runner but last year was running 4-5 miles quite happily. Then I started weight training and packed on a stone and a half of lean muscle to take me to 15.5 stone (5ft 9", 38 yrs old). Picked up the cardio to do some cutting and had the pains when running. Thought it was shin splints and running style. Having seen a sports masseuse, it turns out my leg weight training has been having an effect. I make sure I get the technique right when I'm at the squat rack etc but it appears the stronger glutes have overcompensated for the weaker ones resulting in pelvic stability problems. This has caused my back pain as my hips and pelvis move far too much when running. My arches have dropped and my feet are now flatter and pointing out further meaning I'm over-pronating and overusing the outer shin muscle, causing shin pain. So, not what I thought but I now have some exercises to do and will be looking at motion control running shoes. Should be sorted hopefully in a few weeks. Thought I'd post this in case it helps others.