I've got flat feet. I used to get terrible pain when in my knees when I walked up and down the stairs. Wore insoles with arches for a few months, a few sessions of physio and I was fine.
I remember the physio told me to sit flat on the floor and put a towel round my foot and use it to pull my foot towards me so I was stretching the back of my leg.
I don't know if that's what stopped the pain or a coincidence but I've been ok since. Oh and I was told to wear a shoe with a bit of a heel to give yourself an arch.



