Methods and criteria for assessing dynamic sagittal body balance (non-systematic review)

Radiography of the spine makes it possible to assess disorders in the global sagittal balance of the spine only in statics. Therefore, the assessment of the dynamic sagittal balance according to the data of three-dimensional (3D) gait analysis including the balance of the trunk in general (in the sagittal and frontal planes) and the lumbosacral area, in particular, and determination of the compensatory mechanisms employed by the patient while walking due to the body segments and limbs, is getting more topical. Foreign publications on these topics in the last decade in the search resources of PubMed, e-Library, Cochrane Library and Scholar Google are not numerous, and there are no domestic ones at all, that, in turn, requires an independent detailed study. Purpose Primary analysis of the literature with the identification of methods and criteria for assessing the dynamic balance of the body. Materials and Methods In preparation of the review, the search and information resources of PubMed, eLibrary, Cochrane Library and Scholar Google were used. In the resources of the scientific e-Llibrary, there are no publications on the sagittal dynamic balance, that, in turn, requires an independent detailed analysis. Results and Discussion The postural model that considers the trajectory of movement of the center of mass (CoP) below foot was used to assess the dynamic sagittal balance. It is possible to evaluate the compensatory mechanisms for maintenance of dynamic sagittal balance basing only on the data of three-dimensional (3D) analysis of gait motions. Compensated / decompensated condition of the dynamic balance was defined according to the data of the ground reaction in 3 planes, the motions of the chest with regards to the pelvis, and according to the evaluation of the frontal vertical alignment (CVA-G) and sagittal vertical alignment (SVA-G). Conclusion The standard medical block for 3D gait analysis allows to perform quantitative estimation of compensatory mechanisms for sagittal imbalance, such as in-phase / antiphase coordination pattern of the trunk with regards to the pelvis; the compensated / decompensated condition of the dynamic balance according to the Ground Reaction data in three planes; and compensatory mechanisms, manifested in the parameters of the kinetics and kinematics of the lower limb joints. Assessment of dynamic sagittal balance is carried out in laboratories, where there is a software with an additional calculation option. Two main directions were proposed for its formation, taking into account either the maximum approximation to the X-ray criterion, or to the anatomical position of the center of mass.