So you are 21 years of age, so you will most likely not be sprouting any taller.You are 173CM tall, and 73kg (approx 161 pounds) (approx 5' 7″), and the board is 163cm.Your feet are US sz9 and thebaord is 25cm at the waist.I am sorry to say the board is too big for you. Only slightly, but enough to make a difference. You want a board about 6-10cm shorter and waist width 24.7cm to 24.8cm IMO. On a board like that you will have a MUCH better time on the snow, and hey – that's what it's all about, right?