Until I reached 44, I had normal arches in my feet. Now I'm flat footed! I wear orthotics, which are great, but of course walking barefoot or in sandels you can't use them. I didn't think you became flat footed; I thought you were born with flat feet. Anyone else had this happen to them?
It is caused by loss of muscle tone. Much of the bulging belly of the aged is due to the same.
It can be overcome through stretching exercises. Stretching a muscle regularly improves its tone.
Take up yoga. I was flat footed when I was young but developed arches through yoga which I started when I was 38. I have good arches and I am 50 this year.