What position is the player in, assuming the effect goes off and the player is conscious?
Until the APG content is added to the PRD, you're more likely to get help on APG questions when you reproduce the content in question. I assume you're referring the the determination magic armor ability.
I'm not sure what you mean by "position." Are you asking if the character falls over (as it would if it were rendered unconcsious)?
I think you have to assume the healing from the determination ability is triggered immediately upon having fewer than 1 hit point. Thus there is no status change to the character, so long as the character remains above 0 hit points after the healing. If after applying the healing from determination the character would *still* end up with negative hit points, the character drops and begins dying as normal. (And if after the healing the character has 0 hit points, it's staggered as normal.)