Source:http://linkedlifedata.com/resource/umls/id/C2363644
UMD: Electrogoniometers designed to measure angles along or around two orthogonal planes simultaneously. These goniometers may consist of a small-diameter flexible spring with two sets of plastic blocks on each end, with strain gauge mechanisms housed inside the spring that change electrical resistance proportionally to the change in angle between the longitudinal axes of the end blocks, two independent amplifiers, and possibly an electric meter. The end blocks are usually attached to the limb segments with double-sided adhesive tape. Potentiometric double-axis goniometers are also available; they are designed to cause a potentiometer shaft to rotate proportionally to the joint angle being measured. Double-axis electrogoniometers are intended to measure wrist and radial/ulnar movements in two planes; they are used mainly by rheumatologists and physiotherapists to measure wrist flexion and/or extension and radial/ulnar deviation.