position tracking with IMU Sensor

I use a translator, Sorry...

I want to make it look like the one above, so I want to know where my hand is headed (e.g., biting my nails, smoking, etc.) using the IMU sensor. But i heard it's hard implement position tracking. Then what should do?

HELP!!!

I want to know where my hand is headed

If you don't know where your hand is already, it is hard to see how an Arduino will help. But perhaps you could explain that.