What is the ruling on one who prays the obligatory prayers sitting and does not stand except for the opening takbir while advancing to the front of the row, and what is the ruling on this advancement of his?

It is permissible for a worshipper who is unable to stand or finds excessive difficulty in doing so to pray sitting on a chair or on the ground. He should try to maintain alignment and equality with the row as much as possible. If he is able to stand for the opening Takbir or for reciting Al-Fatiha, then he must do so.