XNA Comparing Kinect movement to a Model movement

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C#

Windows

XBox

Kinect

XNA4.0

I am currently working on a Kinect application which allows recording of movements then later be played on an Avatar in XNA.
I know that the movements captured from the Kinect must be adjusted first and be converted to Matrices as bone transformations before applying it to the Avatar Model.
I came across this project and somehow understand how it must be done. http://msdn.microsoft.com/en-us/library/jj131041.aspx#CommunityContent
I can now successfully store these movements into XML and be played by an Avatar Model.

Another feature of the application I am currently working is, while the Avatar Model is performing the saved movements from my XML file I need to compare a player's live movement which is captured from the Kinect.
My idea is I will compare the movement of the Avatar and the player's movement every second on the fly, however I can't figure out how would I compare the Matrix movements of the Avatar to the Kinect's bone position which is in Vector (X, Y, Z).

Any help would be very much appreciated. Thanks! :D