I am using Kinect (Xbox One) and OptoTrack cameras for human gait analysis. If I place the kinect in frontal plane of the subject, it is giving 3-D values (X,Y, and Z direction) for each joint. Again, it is giving different 3-D values for each joint if I place it in sagittal or transverse plane. Whereas OptoTrack gives 3-D values for each joint which represent sagittal, transverse and frontal plane data of each joint irrespective of camera positions.

Hence, I want to know, does the 3-D values returned by the kinect placed at Sagittal/Frontal/Transverse plane, represents anatomical plane data (like OptoTrack)? If so, then why it is giving 3-D data in each plane? Does OptoTrack anatomical plane data and Kinect 3-D data is same?