first off- your shoulders are rounding forward- i'm assuming you're doing too much bench pressing and not enough back work. add in more back work: pullups, barbell rows, chest supported (tbar) rows.. etc , and some scapula work ( FACE PULLS) <- DO THESE UNLESS YOU WANT SHOULDER PROBLEMS!!!!!!!
Secondly- SQUAT
SQUAT
and DEADLIFT
if you wanna get big you gotta hit those movements, heavy and hard..