Treadmill not recommended by Physio?

In a bit of pain again this morning. Not sure if it's due to the gym session yesterday (even though I did take it very easy). I was planning another light session tomorrow morning, but I'll see how I get on.

One thing I forgot to mention from my Physio session is that the Physio mentioned that generally treadmills aren't recommended for running.  I have never come across this before - I had always thought that the general "give" in the treadmill was easier in the joints.  However, he was saying it isn't recommended because the fact that the treadmill comes towards you means it isn't the same action as when running on the road.  I'll need to investigate this a bit further, as I haven't come across this before.  He did say that the best use of a treadmill is stick it on the highest incline setting and walk, which is good for cardio in any case.