Since I retired I have been spending more of my time at home in house slippers or flat shoes with no support.
This appears to have caused me to develop the condition plantar fasciitis, which is pain of the sole/arch of the foot.
P has a manual of runners' common ailments, which he has had need to consult over very many years, and he advised me to try the golf ball treatment.
When the pain starts, it is only intermittent thankfully, I just roll a golf ball back and forth beneath my foot for around 5 minutes and the pain disappears!
A quick and cheap remedy.