Mine came on after a severe fall on concrete. It affected my left heel, the soles of my feet, both knees, and caused a trigger thumb. Takes well into 11 a.m. for everything to decide to get along. I'm walking gently every other day and have pt exercises given to me before we were shut down in quarantine. Once the quarantine is over, I'll get back to the Nustep machine. It really helps. In the meantime I'm using chiropractic.