1. Apparatus for obtaining proprioception data for a limb or portion thereof of a subject, comprising: a first articulating member having first coupling means for coupling a first limb of a pair of limbs of the subject thereto, the first articulating member moveable in two or more degrees of freedom in 2- or 3-dimensional space and adapted for maintaining the limb in a desired geometry and/or at a desired location and/or for moving the limb through a desired motion in 2- or 3-dimensional space; a second articulating member having second coupling means for coupling a second limb of said pair of limbs of the subject thereto, the second articulating member adapted for being moved by the second limb in two or more degrees of freedom in 2- or 3-dimensional space; wherein the apparatus is configurable to prevent the subject from seeing the first limb or portion thereof and/or the second limb or portion thereof; means for obtaining angular geometry data and/or location data and/or motion data of the first limb in 2- or 3-dimensional space; means for obtaining angular geometry data and/or location data and/or motion data of the second limb in 2- or 3-dimensional space; and means for comparing said data of the first limb with said data of the second limb.