Bizarre observation.
I've an old injury in my right knee, gained when I fell over while out running some years ago. To cut a long story short, I managed to nip the extreme right (lateral) egde of my menical cartilage on my right knee.
If I'm in flat shoes or trainers, I can feel it twinge.
If I'm in high heels, I hardly feel it at all.
It's almost as though the injury is an excuse to crossdress to take pressre off it.
Any physiotherapist types wish to give an explanation as I thought high heels increased pressure on the knees.
I'll add I've pronated feet.
Sue