I don't know if it the same as some of you describe but my right foot is turned inward and rotated to where I walk mostly on the outer edges of it. I have right sided PD. This has progressed to where I have what is called a tailor's bunion as the old time tailors would sit on their stools and turn the foot under them. It has become very painful, my foot is deformed and it has progressed to where I now have pain in the tarsals or larger bones of my foot due to my weight being carried on the edges of my foot. I have been to a podiatrist with no recommendations because it was said that this would simply recurr as PD progressses that he was not aware of any treatment.
I wear out the sides of my shoes before the bottoms!!! I don't get spasms, it's just always turned inwards, oh well..