on my 03, each door has a door check that limits the maximum the door will open, and these also have notches to hold the door at the half and full open positions. Not hard hold, but to hopefully offer enough resistance to keep the door from swinging shut on slight inclines. Also some resistance so the door does fling wide when opened.
On mine these door checks are worn, and offer no resistance or hold anymore. I could replace them, but haven't bothered
Perhaps your 2010 has similar door checks that are worn