Topographic and anatomical analysis and finite element modeling of dynamic and biomechanical displacement patterns of the muscular-fascial cases of the neck

Abstract

Introduction. The issues of dynamic and functional anatomy of the neck are of considerable practical and theoretical interest. This is due to the peculiarities of the displacement of the musculofascial layers when changing the position of the head in space, the description of which presents significant difficulties. Particular practical importance has therefore the study of dynamic phenomena of this area as well as the analysis of morphological and biomechanical changes leading to the development of somatic dysfunction of the neck. Aim. Based on the topographic and anatomical studies, as well as with the help of finite element modeling, to study the patterns of displacement of the muscular-fascial layers of the neck when turning the head by 20º and 50º. Materials and methods. The topographic and anatomical study used the results of 18 MRIs, the analysis of which was carried out using the Vidar Dicom Viewer software. To build a finite element model, data from a CT study of a patient were used, which has not any pathological changes in the organs and musculoskeletal system of the neck. As a result of the subsequent processing of the CT study data, a personalized anthropomorphic finite element model of the neck region was constructed, with the help of which a series of virtual topographic and anatomical studies were performed, repeating in general terms the topographic and anatomical part of the work. Results. 1. The values of rotational and angular displacement of all fascia of the neck are nonlinear. 2. The fascia of the neck are displaced relative to each other when turning the head due to the difference in the values of angular displacement. 3. The magnitude of the angular displacement of the 2nd fascia of the neck at the level C2-C3, C3-C4 and C4-C5 when turning the head 20º, as well as at the  level C4-C5  when turning the  head 50º exceeds the  value of  the angle of  rotation of  the head relative to the trunk. 4. The direction of rotational and angular displacement for all fasciae at the level C6-C7 corresponds to the direction of rotation of the head, with the exception of the dorsal part of the 4th fascia of the neck, which at this level, together with the esophagus, shifts in the opposite direction relative to the axis of symmetry. 5. Fasciae located at a greater distance from the  center of  the intervertebral disc are characterized by large values of  angular and rotational displacement. 6. The rate of change in the ratio of rotational and angular displacements is higher at the level of the lower segments. 7. The results of measurements of the rotational displacement of the fascial layers of the anthropomorphic finite element model demonstrate a positive correlation with the data of the topographic and anatomical study. Conclusion. The patterns of displacement of the neck musculofacial layers should be taken into account when modeling somatic dysfunction of the neck, as well as in the process of diagnosis and planning of osteopathic effects.