Reproducibility of kinematic motion coupling parameters during manual upper cervical axial rotation mobilization: A 3-dimensional in vitro study of the atlanto-axial joint

Reproducibility of global three-dimensional motion during manual atlanto-axial rotation mobilization: anin vitrostudy

“…The accuracy of the system has been demonstrated in previous studies indicating an error of less than 0.2u with each of the three motion components. 19 In all specimens, the skin, subcutaneous tissue, and muscles were dissected, leaving the muscular insertions and ligaments intact. This dissection is necessary to allow full movement and to prevent uncontrolled coupled motions that might occur due to the fixation of the ultrasound system on the segments.…”

“…A graphical representation as well as a mathematical reconstruction of the calculated angles has been presented previously. 19,22 The definition of the local reference frames used by the Zebris system is based on three markers: L (left), R (right), and F (front). The points L were chosen on metal markers inserted on the left transverse process of the axis and atlas respectively, the points R were on the right transverse processes, and the point F was central on the anterior side of the corpus of the atlas and the arcus anterior of the axis.…”

“…The Euclidean norm is defined as the root of the sum of the squared values of the ranges of each separate motion component. This study analyses previous data 19 from a new point of view.…”

“…It has been demonstrated recently that a combination of an in vitro approach using an ultrasound device for continuous motion registration with manual applied mobilization techniques offers the possibility of combining the strengths of an adequate 3D analysis system with performance of a continuous registration of movements in a test-retest situation with two observers. [17][18][19] At present, this is not possible in an in vivo approach. A previous study using this approach demonstrated that the main axial rotation motion component shows adequate intraobserver reproducibility during an axial rotation mobilization of the atlantoaxial spinal motion segment.…”

“…A previous study using this approach demonstrated that the main axial rotation motion component shows adequate intraobserver reproducibility during an axial rotation mobilization of the atlantoaxial spinal motion segment. 19 However, strong variability was demonstrated between the results of different examiners, and the reproducibility of kinematic parameters, including the range of motion of the coupled motion components, the crosscorrelation, the ratio, and the phase shift, was insufficient overall. The relevance of manual examination and mobilization techniques for decision making in diagnostic or therapeutic settings should be studied in a more clinical context taking into consideration these basic results.…”