BUT!!! If you are going barefoot during martial arts and your heels begin to hurt on the bottom (or the inside bottom) then, that may be Plantar Fasciitis. If that begins to happen, get to the Podiatrist or Otho fast!!! Because the longer you put it off, the worse it will be, and the harder it will be to get rid of!!!
Also, no, I do not think that working through the pain is a good idea!! That will only aggrivate the spur or Plantar fasciitis.
hope this helps! Kelus (Janet)