Goniometers and torsiometers are ideal for simple, accurate measurement of joint movement in multiple planes. Sensors are lightweight, flexible, and extremely robust, and can be comfortably worn without hindering the actual movement of the joint, undetected under clothing. The devices provide improved mechanical integrity and electrical performance. The gauge mechanism allows for accurate measurement of polycentric joints. Telescopic endblocks compensate for changes in distance between the two mounting points as the limb moves.