I have been running for four or five years without injury, but this year picked up a nasty attack of ITBS which gives bad knee pain. I understand this to be a very common running complaint, although horribly painful. The reason for relating this is because it seems to have been caused by worn out trainers. I had a pair of Asics running shoes checked on a treadmill before I bought them. Subsequently I've been buying the same make and model from the internet to save on cost, but it seems the manufacturers can make considerable changes over time and this seems to have been so with my shoes.

On top of any changes made by the manufacturers, I'd used my shoes for about 800 miles and when I had them checked during my lay-up from running, I'd developed a horrible over pronation on the afflicted leg. This seems to have been the cause of my problems and I now face a few months building back up to my previous level.

On the whole then;

1. Always get your shoes fitted each time you buy them, and in a treadmill analysis shop. Some do the analysis for free so long as you buy a pair of shoes.
2. Irrespective of the price difference, try to resist buying the same make and model over and over again on the web - if neccessary take them into a gait analysis place once a year, to make sure they are still right for you.
3. Retire shoes after 600 miles, or possibly less.
4. Never attempt to run through an injury - months of recovery are never worth "just finishing the run".

Good luck !

One thing I have found, with people suffering knee pain, is that sometimes runners are advised by well meaning people, to buy support shoes, when in actual fact they don't need them and would be less likely to suffer if they wore neutral shoes.  We must all pronate (when the foot flattens and becomes a loose bag of bones essentially) to absorb shock, so if your shoes stop you pronating too much then your knees will have to absorb more shock than they are really designed to do.  That said, if you pronate the whole way through your gait then you do need some support or better still orthotics made for you particular biomechanics.

A big reason for over pronation is tight muscles.  A good post run, stretching program performed for absolutely every run, can improve knee pain, in those runners who are not naturally supple (that's me and lots of others).

I would be interested to know how people are getting on with Newton trainers, good and bad. Hope this helps.

I'd recommend taking up yoga (specifically Iyengar Yoga) to improve the health of the knees and hips which are most the most common injuries in runners. I have been practising and tecahing yoga for 11 years now and can't remember the last time I had any form of injury from running.

Very good website for information is www.yogaforrunners.co.uk or for a qualified yoga instructor www.iyengaryoga.org.uk