The assessment of spine mobility is an important parameter to define its functionality. In the last decades a lot of research has been carried out mainly through radiographic investigations; non invasive methods demonstrated not to be sufficiently accurate, not to allow free movement, not to provide metameric assessment and suitable for everyday clinical practice. The aim of this study is the development of a new experimental non invasive protocol, called Zoom on mobility of the spine (ZooMS) to assess the mobility of lumbar spine, from the 11th thoracic to the sacrum bone and the pelvis, with the possibility of identifying the metameric contribution of each rotation around all the axes correlated to the global movement.We developed a dedicated non invasive methodology based on optoelectronic techniques for 3D target recording to be applied to the functional evaluation of the mobility of the lumbar spine in young healthy males. Ten subjects participated in the method validation, performing free rotations (flexion/extension, lateral bending and axial rotation) from standing to the maximum excursion and back.The comparison of the range of motion (RoM) with those presented in literature was satisfactory, although some differences were shown (above all in axial rotation, which however gives the minor contribution to the mobility of the lumbar spine). The validation of the protocol was successful in terms of intraoperator, interoperator and circadian remarking, the 3 factors eventually affecting its repeatability.The RoM of the whole lumbar spine and of each functional unit, together with the pattern of movement may so represent an innovative and important aspect in clinical applications
