I was sent to a podiatrist by my doc, when I realised I had flat feet. As I walked in the podiatrist said, "yeah they're flat .... I bet you have knee problems too."
Damn right. I'd suffered from patella tendonitis for around 15 years into my 30s until this fella made some inserts for my shoes that encouraged me to arch my feet. My tendonitis cleared up in a matter of days. It's to do with knee rotation caused by fallen arches.
I'd been to the docs multiple times about my knee problem before giving up and just tolerating it With pain killers on his advice. It was agonising after and during sport.
That doc probably robbed me of a pro football career. At least that's what I told myself.