What should a person do if it is too hard for him when the imam prostrates for a long time?
Question

                If it is too hard for me when the imam prostrates for a long time, what should I do? Should I prostrate with the imam then rise before him, or delay prostrating behind him?.
Praise be to Allah.
    If he cannot prostrate from the time when the imam says the 
    takbeer until he rises, then he should prostrate with the imam, then if it 
    becomes too hard for him to continue prostrating, he may rise a little but 
    stay as close as possible to the ground, and this will not mean that he is 
    differing from his imam. If he cannot prostrate on the ground, then he may 
    prostrate as close as he can to the ground. End quote. 

    Shaykh Muhammad ibn Ibraaheem (may Allaah have mercy on him).