I twisted my ankles a number of times when I was younger, and a doctor told me to wear footwear that offers solid ankle support. I complied with his advice, and stopped twisting my ankles.
My boss (both consulting company and client) initially said I could wear boots if I complied with HR, but changed his mind and has said that the question of whether I may wear boots is decided alone by whether he wants to have an executive ask him why I wear boots. It's not so far as I can tell that he believes that it's not a reasonable accommodation; the question of reasonable accommodation does not appear to be in his mental picture.
I'm a bit concerned for this, partly from wearing shoes at work that won't protect my ankles, partly because of a matter of, "If this is the response I get when I wear boots, what will happen when I need his help for a real problem?"
(When I tried to press the point, he brought in both the recruiters and had a meeting explaining that it is a formal workplace with formal expectations, and they did not think to explain that boots were not appropriate.)
How can I address this problem constructively concerning my physical health and my workplaces need for more professional attire?
--EDIT--
After he brought in the recruiters and made it clear, dramatically, that I was not to wear non-dress footwear to work, I sent an email to the closest public email address I could find to human resources, a media relations address, and requested to be able to wear my workboots for as long as it took for dress boots to arrive. As requested, I worked with my manager to determine an appropriate pair of boots, and ordered them before the end of the day.
A week later than I began, to the day, my recruiter came to my desk and explained that I was fired for contacting HR, as my email had then trickled down, and that was visibility that was not appropriate to his highly visible area. I was told not to have contact with my former company except as mediated by my recruiters.
The next day, the dress boots I ordered arrived. They look great. If only I could wear them to work...