Well, you know that "ambulant" means to walk. Ambulant in another format. Medically related (E.G. "...his flow is quite unfair tothe service and Sir E. Phipps rightly complained of these ambulant amateurs.")
Use it's (with the apostrophe) only when you mean "it is" or "it has." For example: It's time to go. (It is time to go.)It's been a long time. (It has been a long time.) Use its (without the...