Calculated indicator of dynamic axial balance of the body — its reproducibility and repeatability by variation coefficient

Background: Justification. Age-related changes are accompanied by structural disorders not only in the bones of the skeleton, but also in the weakening of sensorimotor systems that regulate the biomechanical functions of the entire musculoskeletal system and in particular the spine. Although visually, the observed balancing disorders are particularly noticeable in the postural functions of balance and the axial skeleton, their quantitative instrumental assessment and diagnosis have not yet been worked out. To date, 3D video gait analysis is a recognized objective research method that allows orthostatics and walking to record and quantify the basic balancing values of the axial skeleton.

Aim: To study the balancing behavior of the axial skeleton in locomotor activity and establish normative statistical guidelines for its balancing characteristics in a three-coordinate space.

Materials and methods: The study involved men (n=10) and women (n=9) aged 18–40, with an average age of 31.1±1.4 years. Qualisys 7+ optical cameras (8 cameras) with passive marker video capture technology recorded kinematic gait parameters. A specially created program determined the values of dynamic axial balance by the amplitude of the projection of the calculated points from the center of the C7 and S2 vertebrae to the reference plane in the sagittal (GA-SVA) and frontal (GA-CVA) planes and the angle range of the projection of the shoulder and pelvis lines in the horizontal (GA-APA) plane.

Results: The stochastic dynamics of the axial balance of the body analyzed in the study approached the normal distribution function with the lowest level of variation in the horizontal plane. The ranges of coefficients of variation of the axial balance of the body during normal walking "on tiptoes" were: in the horizontal plane (APA) — 7.5%–10.0%; in the sagittal plane SVA — 12.4%–18.6%; in the frontal plane CVA — 12.6%–16.9%.

Conclusion: The statistics of reference values of the dynamic axial balance of the body in the age group of 18–40 years with normal walking and with the functional test "walking on toes" are presented. In the locomotor stochastic hierarchy of biomechanical functions of the axial skeleton, the normalized values of the three-coordinate parameter of axial balance (PAB), should be considered the leading diagnostic guideline in assessing motor pathology, since the distribution of its values is constant and may correspond to the rule of sigma deviations.

1. Haddas R, Kosztowski T, Mar D, et all. Balance effort, Cone of Economy, and dynamic compensatory mechanisms in common degenerative spinal pathologies. Gait & Posture. 2021:89(9):67-73. doi: https://doi.org/10.1016/j.gaitpost.2021.04.038

2. Ivanov DV, Kirillova IV, Kossovich LYu, et all. Comparative analysis of the SpinoMeter mobile application and Surgimap system for measuring the sagittal balance parameters: inter-observer reliability test. Genij Ortopedii. 2021;27(1):74-79 (In Russ.). doi: https://doi.org/10.18019/1028-4427-2021-27-1-74-79

3. Rizzato A, Benazzato M, Cognolato M, Grigoletto D, Paoli A, Marcolin G. Different neuromuscular control mechanisms regulate static and dynamic balance: A center-of-pressure analysis in young adults. Human Movement Science. 2023;90:103120. doi: https://doi.org/10.1016/j.humov.2023.103120.

4. Dolganova TI, Aksenov AYu, Ryabykh SO, Garipov II. Methods and Criteria for Assessing Dynamic Sagittal Body Balance (Non-systematic Review). Genij Ortopedii. 2021;27(6):827-833 (In Russ.). doi: https://doi.org/10.18019/1028-4427-2021-27-6-827-833

5. Shulga АE, Zaretskov VV, Ostrovskij VV, et all. Peculiarities of the sagittal balance of patients with post-traumatic deformities of the thoracic and lumbar spine. Genij Ortopedii. 2021; 27(6):709-716. (In Russ.). doi: https://doi.org/10.18019/1028-4427-2021-27-6-709-716

6. Dolganova TI, Aksenov AYu, Garipov II, et all Quantitative assessment of the sagittal and coronal balance of the axial skeleton using 3D motion capture. Genij Ortopedii. 2023;29(3):307-315 (In Russ.). doi: https://doi.org/10.18019/1028-4427-2023-29-3-307-315

7. Byalovsky YuYu, Rakitina IS. Repeatability of the assessment of perception of different values of additional respiratory resistance. Crimean Journal of Experimental and Clinical Medicine. 2022;12(2):21-27(In Russ). doi: https://doi.org/10.37279/2224-6444-2022-12-2-21-27

8. Mamaev AН, Kudlai DА. Statistical methods in medicine. M. Practical medicine. 2022:136 (In Russ).

9. Almarwani M, VanSwearingen J, Perera S, Sparto PJ, Brach JS. Challenging the motor control of walking: Gait variability during slower and faster pace walking conditions in younger and older adults. Arch. Gerontol. Geriatr. 2016;66:54–61. doi: https://doi.org/10.1016/j.archger.2016.05.001

10. Nardone A, Tarantola J, Galante M, Schieppati M. Time course of stabilometric changes after a strenuous treadmill exercise. Archives of physical medicine and rehabilitation. 1998;79(8):920-924. doi: https://doi.org/10.1016/s0003-9993(98)90088-0

11. Aksenov AYu, Klishkovskaya TA, Dolganova TI. Program for analyzing the dynamic balance of the axial skeleton in locomotor stereotypes based on 3D video analysis data. Certificate of state registration of the program of the Russian Federation No. 2022684723; published December 16, 2022. (In Russ).

12. Pesenti S, Pomero V, Prost S, et all. Curve location influences spinal balance in coronal and sagittal planes but not transversal trunk motion in adolescents with idiopathic scoliosis: a prospective observational study. Eur. Spine J. 2020;29:1972–1980. doi: https://doi.org/10.1007/s00586-020-06361-3

13. Zaitsev GN. Methodology of biometric calculations. Mathematical statistics in experimental botany. Moscow, «Nauka» 1973. 256 p. (In Russ).

14. Ferreira F, Gago MF, Bicho E, et all. Gait stride-to-stride variability and foot clearance pattern analysis in Idiopathic Parkinson’s Disease and Vascular Parkinsonism. J Biomech. 2019;92:98-104. doi: https://doi.org/10.1016/j.jbiomech.2019.05.039

15. Kim B, Youm C, Park H, Lee M, Noh B. Characteristics of Gait Variability in the Elderly While Walking on a Treadmill with Gait Speed Variation. Int J Environ Res Public Health. 2021;18(9):4704. doi: https://doi.org/10.3390/ijerph18094704

16. Verbecque E, Vereeck L, Van de Heyning P, Hallemans A. Gait and its components in typically developing preschoolers. Gait Posture. 2017;58:300-306. doi: https://doi.org/10.1016/j.gaitpost.2017.08.012

17. Hasegawa K, Dubousset JF. Cone of Economy with the Chain of Balance-Historical Perspective and Proof of Concept. Spine Surg Relat Res. 2022;6(4):337-349. doi: https://doi.org/10.22603/ssrr.2022-0038

18. De Blasiis P, Caravaggi P, Fullin A, et all. Postural stability and plantar pressure parameters in healthy subjects: variability, correlation analysis and differences under open and closed eye conditions. Front Bioeng Biotechnol. 2023;11:1198120. doi: https://doi.org/10.3389/fbioe.2023.1198120

19. Haddas R, Satin A, Lieberman I. What is actually happening inside the «cone of economy»: compensatory mechanisms during a dynamic balance test. Eur Spine J. 2020;29(9):2319-2328. doi: https://doi.org/10.1007/s00586-020-06411-w

20. El-Gohary TM, Al-Shenqiti AM, Ibrahim SR, Khaled OA, Elkader SMA. Clinical measurements of spinal mobility, static balance, and functional performance in healthy participants: a simple biokinesiological analysis of performance. J Phys Ther Sci. 2019;31(10):771-775. doi: https://doi.org/10.1589/jpts.31.771

21. Dolganov DV, Aksenov AYu, Dolganova TI, Cherepanov ID. Rotational component of the trunk in locomotor stereotypes in healthy children. Russian Journal of Biomechanics. 2025;29(1):144–153 (In Russ.). doi: https://doi.org/10.15593/RZhBiomeh/2025.1.09

22. Haddas R, Sambhariya V, Kosztowski T, Block A, Lieberman I. Cone of economy classification: evolution, concept of stability, severity level, and correlation to patient-reported outcome scores. Eur Spine J. 2021;30(8):2271-2282. doi: https://doi.org/10.1007/s00586-020-06678-z

23. Dubousset J. Three-dimensionality in vertebral pathology: the horizontal plane is hidden in every scoliotic deformity. Russian Journal of Spine Surgery (Khirurgiya Pozvonochnika). 2021;18(2):93-103. (In Russ). doi: https://doi.org/10.14531/ss2021.2.93-103

24. Lee T, Lee M, Youm C, Noh B, Park H. Association between Gait Variability and Gait-Ability Decline in Elderly Women with Subthreshold Insomnia Stage. Int. J. Environ. Res. Public Health. 2020;17:5181. doi: https://doi.org/10.3390/ijerph17145181