Today I went back to see the podiatrist.
After I received my temporary orthotic insoles, I wore them all the time – for about four days. By then, my right knee was complaining – a lot. So I guessed that the insoles might be the cause and stopped wearing them for a week (which coincided with some snow). My knee felt better, but didn’t stop hurting altogether. I tried the insoles again (building up from ‘occasionally’ to ‘most of the time’) and it didn’t get any worse, but it didn’t go away, either. When I spoke to my physio last week, she confirmed that orthotic insoles can cause knee pain, and offered a ‘knee assessment’ when I next see her.
After I told the podiatrist this, she told me not to use the orthotic insoles any more. My gait abnormality is relatively minor (and, I suspect, has been present for many years without causing a problem); it would probably have never come to light if my physio hadn’t spotted it. We agreed that the pain I’ve been feeling in the side of my foot is most likely to be due to the Parkinsonian muscular tension (making my toes curl).