Abstract: The device concerns a chair (10), which includes an at least partly resilient seat part (12). The seat part (12) of the chair is provided with support elements (14, 15) placed at both sides of the imaginary longitudinal and vertical centre plane (A) of the seat part, which elements are fitted to produce a force and movement that raises the seat part (12) variably and alternatingly. Favourably, the support elements (14, 15) are interconnected so that, when a substantially vertical load is applied to one support element (14/15), said load produces an increasing support force of a direction opposite to said load in the other support element (15/14). Preferably, the support elements consist of interconnected resilient elements (14, 15) so that, when external, substantially vertical loads of different magnitudes are applied to said resilient elements (14, 15), the resilient element (14/15) that is subjected to a higher load produces a force and movement of opposite direction in the other resilient element (15/14).

Abstract: The present invention is for a non-invasive pain provocative means for diagnosing spinal disorders. The device is a hand-held instrument which can be used in any doctor's office to differentiate which intervertebral disc is responsible for a patient's symptoms. The device produces pain by applying vibrations to the spinous process above a degenerated disc. The device has a handle for a user to easily grip, a vibration means located within the handle, and a detachable applicator positioned distally on the handle. The applicator, having many embodiments, is the element of the device which is applied to the patient's spine, in particular, to the spinous processes of the spine. This device can be useful in predicting a problem before an acute episode occurs or in staging the disc degeneration process or in screening people for certain jobs that have a high incidence of disc injury or trauma.