Knee Recording Joint movement (Knee)

Hello Everybody

I currently working on a project related to measuring the movement of the human knee. I am hoping to measure range of motion and orientation but I want to take things slow and work on it piece by piece to ensure I dont get to far ahead of myself. First off i would just like to ask a few technical hardware questions before i start soldering writing code.

So I have looked at accelerometers and gyroscopes as well as stretch sensors in combination with a tilt sensor for the actual record of movement of the joint.

I would like to work with an arduino pro mini because of the size and portability if possible

  1. can you attach the accelerometer signal pins to digital pins? or do they only work with analog pins?
  2. is there a better way to record this type of data

This sounds like the sort of thing to do some inital leg work on [sorry for the pun],

http://www.google.com/search?q=electronic+goniometer&hl=en&tbo=u&tbm=isch&source=univ&biw=990&bih=867&sei=3bLrUPqXK4WSiAL92IGIDw

hey jus try using a potentiometer with some mechanical changes this will be really effective .
i had already tried this to find the angle of a robotic arm.
The change in resistance can be noted at each angle.