Track displacement with IMU's

I want to use two IMU's in order to track human head position. I have heard it is very hard to track total displacement using one IMU, but all I want to do is calculate the x-displacement between the two IMU's. They will both start at the same position, and as I begin to move one of the IMU's upwards, I just want to know how far left or right the moving IMU is from the starting position. Would I be able to do this accurately with two MPU 6050's?

Thanks!

See http://www.chrobotics.com/library/accel-position-velocity

I read the page, but I would be doing my measurements on a pretty small scale, like deviations of 5cm max. My main goal is to be indicated when the two IMU's are aligned, would that be possible, or would there be too much error involved?

Try it and see.