Device for measuring lumbar spinal movement

An apparatus for measuring motion of the lumbar spine of a subject about five axes, comprising:

• an articulating enclosure including first and second housing and a third housing remotely connected to said second housing by a connecting means;
• first pivot means joining said first and second housings for relative motion about a first, horizontal axis;
• first plate means pivotally mounted to the first housing;
• said first plate means being adapted to be secured to the back of a subject at the base of the lumbar spine with the first housing vertically aligned under the second and third housing and with the first axis located transversely across the lumbar spine;
• second plate means pivotally mounted to the third housing;
• the second plate means being adapted to be secured to the subject adjacent to the top of the lumbar spine;
• second pivot means operably mounting said first plate means to the first housing about a second horizontal axis that is perpendicular to the first horizontal axis;
• third pivot means operably connecting said connecting means and second housing about a third vertical axis which is perpendicular to both said first and second axis, and coextensive with said connecting means;
• fourth pivot means operably connecting said second plate means and said third housing about a fourth horizontal axis which is parallel to said first axis;
• fifth pivot means operably connecting said third housing to said connecting means about a fifth horizontal axis which is parallel to said second horizontal axis;
• a plurality of sensing means each responsive respectively to relative pivotal motion of each of said pivot means about their respective axis;
• and means for receiving and transmitting to a register, signals produced by said sensing means in response to said pivotal motion.