Evaluation of the complexity of the motor task from the point of view of muscle activation





muscle synchronization, muscle coordination, two-joint movements, electromyographic activity (EMG), principal component analysis (PCA), tracking accuracy.


Today, many specialists from various fields, such as physiology, biology, rehabilitation, traumatology and others, are actively researching the functioning of the musculoskeletal system and its relationship with the central nervous system. This is a very relevant topic in today's world, as various factors such as traumatic injury, chronic or hereditary disease, neurological impairment and the aging process have a direct impact on the state of the musculoskeletal system, muscle function and movement coordination. One of our goals is to study the dynamics of two-joint equilibrium muscle contraction in order to determine the final forces created by the right upper limb of a person in the horizontal plane.

We are conducting a study in which the electromyographic (EMG) activity of the muscles of the shoulder and shoulder girdle, as well as the spatial and force parameters of movements that occur during free two-joint efforts, are studied. The purpose of this study is the process and mechanism of central coordination of motor commands sent to the muscles of the shoulder and shoulder girdle during bicondylar movements, especially when performing targeted efforts with the hand, in the presence of visual control.

Synchronization and coordination of the muscles of the shoulder and shoulder girdle during the performance of two-joint movements were studied in an experiment with experimental subjects. By recording the electromyographic activity of 8 muscles and calculating the moments of forces generated by the muscles, it was found that muscle synchronization was more pronounced during elbow flexion, and muscle coordination - during shoulder extension.

The findings of the study indicate that the muscles of the shoulder and shoulder girdle work in a synchronous and coordinated mode during two-joint movements. Muscle synchronization and coordination appeared to be important for precise movement control, with elbow flexion and shoulder extension showing greater accuracy compared to other movements.


Van Vliet, P.M.; Heneghan, N.R. Motor control and the management of musculoskeletal dysfunction. Man Ther. 2006. Jun. 11 (3) 208-13, https://doi.org/10.1016/j.math.2006.03.009

Cheung, V.C.; Turolla, A.; Agostini, M.;Silvoni, S.;Bennis, C.; Kasi, P.; Paganoni, S.; Bonato, P.;& Bizzi, E. (2012, Sep). Muscle synergy patterns as physiological markers of motor cortical damage. Proc Natl Acad Sci U S A, 109(36):14652-6. https://doi.org/10.1073/pnas.1212056109

Dimitra Paggou; Leonidas Stefanis; Efstathios Chronopoulos; Apostolia Ghika; Andreas Kyrozis; Alexia Balanika; Christos Baltas; Constantin Potagas (2023, Jun). Shoulder Dysfunction in Parkinson Disease: Review of Clinical, Imaging Findings and Contributing Factors. J Musculoskelet Neuronal Interact. 23(2). Pp 263-280. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10233223/

Luka Križaj; Žiga Kozinc; Stefan Löfler; Nejc Šarabon. The chronic effects of eccentric exercise interventions in different populations: an umbrella review. Eur J Transl Myol. 2022. 32(4):10876. https://doi.org/10.4081/ejtm.2022.10876

Massimo Sartori; Francesco Negro; Dario Farina. (2020, Apr). Neuro-Musculoskeletal Mapping for Man-Machine Interfacing, 10(1):5834, https://www.nature.com/articles/s41598-020-62773-7

Rossero M; Ciullo AS; Grioli G; Catalano MG; Bicchi A. Analysis of Compensatory Movements Using a Supernumerary Robotic Hand for Upper Limb Assistance.

Frontiers in Robotics and AI. 2020. 7:587759. https://doi.org/10.3389/frobt.2020.587759

Кostyukov A.I.; Gorkovenko A.V.; Kulyk Y.A.; Lehedza O.V.; Shushuiev D.I.; Zasada M.; Strafun S.S. Central Commands to the Elbow and Shoulder Muscles During Circular Planar Movements of Hand With Simultaneous Generation of Tangential Forces. Front Physiol. 2022. 13:864404.


Culham, E.; Peat, M. Functional anatomy of the shoulder complex. J Orthop Sports Phys Ther. 1993. 18(1). Pp. 342-50. https://www.jospt.org/doi/10.2519/jospt.1993.18.1.342

Синельников Р. Д. Атлас анатомії людини в 3-х томах. Том 1. Вивчення кісток, суглобів, зв'язок і м'язів. 2-е вид. HYML 1963

Muceli, S.; Boye, A.T.; d'Avella, A.; Farina, D. Identifying representative synergy matrices for describing muscular activation patterns during multidirectional reaching in the horizontal plane. J Neurophysiol. 2010. 103(3), pp. 1532-42. https://doi.org/10.1152/jn.00559.2009

Boland, M.R.; Spigelman, T.; Uhl T.L. The function of brachioradialis. J Hand Surg Am, 2008. 33(10) , pp 1853-9. https://doi.org/10.1016/j.jhsa.2008.07.019

Buchanan, T.S.; Rovai, G.P.; Rymer, W.Z. Strategies for muscle activation during isometric torque generation at the human elbow. J Neurophysiol. 1989. 62(6), pp 1201-12. https://doi.org/10.1152/jn.1989.62.6.1201

Gribble, P.L.; Mullin, L.I.; Cothros, N.; Mattar, A. (2003, May). Role of cocontraction in arm movement accuracy. J Neurophysiol. 89(5):2396-405, https://doi.org/10.1152/jn.01020.2002

Vereschaka, I.V.; Gorkovenko, A.V. (2011, Nov). Central Activation of the Upper Limb Muscles in Humans Related to Creation of an Isometric Effort: Dependence on the Position of the Point of Force Application within the Operational Space. Neurophysiology. 43, pp 248-250. https://link.springer.com/article/10.1007/s11062-011-9212-6

Zasada, M.; Gorkovenko, A.V.; Strafun, S.S.; Vasylenko, D.A.; Pilewska, W., Kulyk, Yu.A.; Kostyukov, A.I. A New Approach to the Study of Two-Joint Upper Limb Movements in Humans: Independent Programming of the Positioning and Force. Neurophysiology. 2020. 52, pp 397-406. https://link.springer.com/article/10.1007/s11062-021-09896-3

Lehedza O. V. Manifestations of Hysteresis in EMG Activity of Muscles of the Human Upper Limb in Generation of Cyclic Isometric Efforts. Neurophysiology. 2017. 49, pp 220–225. https://doi.org/10.1007/s11062-017-9667-1





Human and Animal Physiology

How to Cite

Evaluation of the complexity of the motor task from the point of view of muscle activation. (2023). Notes in Current Biology, 6(2). https://doi.org/10.29038/NCBio.23.2-14