Statistical analysis of 3D coordinates and distances

Hi all,

I'm evaluating two different techniques of identifying the representation of the motor network within the brain. Both techniques identify the center of gravity of the motor network in MRI coordinates based on physiological output. So what I have is 8 datasets of coordinates for both techniques. The 2 techniques clearly identify different centers of gravity and I would like to quantify this. However, it is hard to determine whether the coordinates/distances are normally distributed due to the limited sample size. I am currently running a t-test on the x coordinate (which is most relevant) and a one-sided t test on the distance (which I'm not sure is accurate). Any advise would be very helpful.