This invention is a minimally-invasive device, including bone-moving members and motion-measuring members, that can help surgeons to obtain objective, quantitative information concerning spinal flexion, extension, lateral bending, decompression, compression and torsion in order to select the best therapy for each patient. The prior art does not offer surgeons the opportunity to objectively and independently measure each of these movements. As a result, currently there is tremendous variation concerning which therapies are selected for which conditions. It is very unlikely that quality is being optimized and costs are being best managed with such high variation in practice patterns. This variation may be greatly reduced by the availability of objective information concerning spinal motion from this device. In this manner, this device can help surgeons to select the optimal therapy, to improve the quality of care, and to reduce the risk and expense of unnecessary spinal procedures and hardware.