After graduating and suffering from shin splints I visited my local running shop, had a gait analysis done and jeez.... no wonder I had shin splints!
What I thought were a good pair of running shoes were absolutely useless. My initial impact is pretty standard, but the roll inwards during my step was horrifying to watch in slow motion, actually looked like my ankles were about to dislocate. I was assured that a lot of people suffer from this, and a decent pair of shoes would resolve it.
OK the shoes were expensive at £120, but they were in the sale, and I got the cost of my gait analysis back so ended up paying £80. Still a lot of money in my book, but, and here's the value for money bit, after three weeks of no running, I'm back upto 4k with no pain at all. I'm going to slowly work back to the 5k and maintain there for a month or so before I go any further, but this rather long post is just to promote the advantages of proper running shoes over generic trainers.
Who would have thought that something as simple as putting one foot in front of the other repeatedly would be so scientific!!