Skeletal muscle contraction in protecting joints and bones by absorbing mechanical impacts
We have previously hypothesized that the dissipation of mechanical energy of external impact is a fundamental function of skeletal muscle in addition to its primary function to convert chemical energy into mechanical energy. In this paper, a mathematical justification of this hypothesis is presented. First, a simple mechanical model, in which the muscle is considered as a simple Hookean spring, is considered. This analysis serves as an introduction to the consideration of a biomechanical model taking into account the molecular mechanism of muscle contraction, kinetics of myosin bridges, sarcomere dynamics, and tension of muscle fibers. It is shown that a muscle behaves like a nonlinear and adaptive spring tempering the force of impact and increasing the duration of the collision. The temporal profiles of muscle reaction to the impact as functions of the levels of muscle contraction, durations of the impact front, and the time constants of myosin bridges closing, are obtained. The absorption of mechanical shock energy is achieved due to the increased viscoelasticity of the contracting skeletal muscle. Controlling the contraction level allows for the optimization of the stiffness and viscosity of the muscle necessary for the protection of the joints and bones.
Keywordsbiomechanics acoustical testing skeletal muscle muscle viscoelasticity muscle contraction skeletal system
Unable to display preview. Download preview PDF.
- 3.A. Sarvazyan, in Handbook of Elastic Properties of Solids, Liquids and Gases, Vol. 3. Elastic Properties of Solids: Theory, Elements and Compounds, Novel Materials, echnological Materials, Alloys, and Building Materials, Ed. by M. Levy, H. E. Bass, R.R. Stern, and V. Keppens, (Academic, 2001), Ch. 5, pp. 107–127.Google Scholar
- 4.A. P. Sarvazyan and C. R. Hill, in Physical Principles of Medical Ultrasonics. Ed. by C. R. Hill, J. C. Bamber, and G. R. TerHaar (Wiley, 2004), Ch. 7, pp. 223–235.Google Scholar
- 6.T. A. Krouskop, D. R. Dougherty, and F. S. Vinson, J. Rehabil. Res. Dev. 24, 1 (1987).Google Scholar
- 31.J. J. Ballyns, D. Turo, P. Otto, J. P. Shah, J. Hammond, T. Gebreab, L. H. Gerber, and S. Sikdar, J. Ultrasound Med. 31, 1209 (2012).Google Scholar
- 38.D. T. Kirkendall and W. E. Garrett Jr, J. Athl. Train. 36, 328 (2001).Google Scholar
- 39.A. I. King and D. C. Viano, in Biomechanics: Principles and Applications, Ed. by D. J. Schneck and J. D. Bronzino, (CRC Press, 2002), 1st ed., Ch. 6, pp. 107–118.Google Scholar
- 42.V. I. Deshcherevskiĭ, Biorheology 7, 147 (1971).Google Scholar
- 44.L. D. Landau, E. M. Lifshitz. Course of Theoretical Physics, Vol. 6. Fluid Mechanics, (Pergamon Press, 1987), § 81.Google Scholar