I'm not sure if this is correct, I'm more trying to give you some sort of idea before an actual professional comes to help you but...
I think, do you have variables for your character? like "climbing" or some sort of state that controls/tells the game "the player is currently climbing" ?
Perhaps check if right after he is "done climbing" play the animation of his arms supporting him up.
Maybe place uhm... imagepoints on your ladders at the required places - and when your sprite collides with them have the animation play out?
Maybe when the sprite collides with the top of the ladder, set a thing to prepare him for "Getting up" and make the getting up animation play before you can fully move your character?
I hope I helped, sorry its pretty scatter brained. Here let me fix it a bit...
Try placing an image point near the top of the ladder, when your player is overlapping it, have the animation play of him getting up.