You clearly need to work on your slow shuffle if you can't even get it over 5min/km.
Must admit I was surprised when I looked at my watch. I really was trying. I think I’m running so little that my legs are always pretty fresh... certainly felt like I had a short stride and no knee lift.
Doesn’t make much difference if I can’t do it without it hurting anyway. Not exactly in shape for a long run, or any sort of race.
You've always had a short stride (for your height) and no knee lift! 5mins per km does not in any way qualify as slow shuffle. You may label it 'Slower than Normal Run'. Sheesh. Some perspective Fletch. ;-)
I can never really manage >5min/km for easy runs either.