what does the medical term called accessory navicular
What makes this matter confusing is that some people have what is called an accessory navicular bone. Essentially, this is an extra bone that is located on the inside portion of the foot, at approximately the arch, and it is in addition to the standard navicular at the top of the foot.
The term navicular bone tends to refer to a bone at the top of the foot, located in close proximity to where foot and ankle meet. While most people will now accept this as the location of the bone, a bone in the wrist, most often called the scaphoid bone, used to be called the navicular too.