Okay, I'm not going to surgar coat it for you:
Standing at almost 5'10", sometimes even I would be considered to short for the runway, depending on the designer. The average for runway is 5'11". For editorial print, the cut-off is 5'9". Just about the only thing they'll take 5'6" for, are dept. store catalogs and convenience store ads... they could never use someone that height to display high fashion, Haute Couture, or Prête à Porter, they always want a longer canvas, you see?
-But-
Of course there are exceptions. Kate Moss rose to super model status even being short at 5'6"... but you have to look at that objectively. She did not get to fame wearing couture on the runway...she would have tripped on the dresses. She had the instinctive ability to pose, which is something most models lack, hence even though she was short, a simple classic label like Calvin Klein offered her a contract. Notice alot of the contracts she's ever had... everything with posing... handbags, lipstick. Sometimes she gets designer labels, but they are of the simplier (non-fancy variety) Burberry, Klein, etc. But still, look how well she's done.
With plus size modelling (size 8 - 14) they relax the height a little bit, so the average is about 5'10", both in editorial and runway. I think they may take someone 5'8", but 5'7" is so much on the edge that I don't know about your situation. I think it's case by case. You have to be a very exceptional person to fill the shoes without the height.
All in all, what I'm saying is, yes, there is a "standard", and the industry does not typically like to deviate from it. And while there is nothing you can do about your height, the body is such a workable, moldable thing, that you do have some leeway to become the next exceptiopnal model. Work hard and perservere, you may find just that opening you're looking for.
