Ok I'm back..well intend to be.
Seems The 5k+ should be taken on by people without weak backs..ie ME.
I have been layed up with severe back pain since doing three Stamina runs silly me I'm, 48 slightly overwieght (oh OK a lot) and now it appears I have a weak back............
So i'm going back to general running as per the C25K (normal)
Might even use the treadmill (if wife allows ) as less impact so i'm reading.