Biomechanics of Human Passive Muscles

Links

URL: http://handle.unsw.edu.au/1959.4/51391

Abstract

This project described the passive biomechanical properties of human gastrocnemius muscle-tendon unit, which is less understood in the literature. Currently most work has been done on the passive biomechanical aspect of human skeletal muscles only examined the elastic behaviour of human skeletal muscles, the effect of the viscous component was not considered. Therefore, the main aim of this project is to characterize the viscoelastic properties of human gastrocnemius muscle-tendon unit by using quasi-linear viscoelastic theory, and further to model both elastic and viscous behaviours of human gastrocnemius muscle-tendon unit in vivo under passive conditions.

The research project consists of four interrelated studies, which include 1) characterize the viscoelastic properties of human gastrocnemius muscle-tendon unit by using quasi-linear viscoelastic theory; 2) characterize the stress-relaxation properties at the human ankle joint, which is important to be determined before applying quasi-linear viscoelastic theory; 3) review current techniques for estimating the muscle-tendon moment arm, and examine the validity of the measurement of gastrocnemius muscle-tendon moment arm length used in this project; 4) explore the intermuscular force transmission between the human medial gastrocnemius muscle-tendon unit and soleus muscle-tendon unit in vivo under passive conditions, which examine the validity of the assumption made in this project. The first study in Chapter 2 reviewed current methodologies to estimate human muscle-tendon moment arms, and examined the limitation of each method. Some recommendations were provided to accurately determine human muscle-tendon moment arms for future studies.

The second study shown in Chapter 3 characterized the stress-relaxation properties at the human ankle joint, this is important for creating robust models of viscoelastic behaviour using quasi-linear viscoelastic theory. It was found the stress relaxation in the relaxed human ankle is minimally affected by changing joint angles. Consequently, a common stress-relaxation modulus can be applied in quasi-linear viscoelastic models of the relaxed human ankle, with minimal error.

Chapter 4 as the third study in this project covers the main study: to characterize the passive viscoelastic behaviours of human gastrocnemius muscle-tendon unit in vivo. The results showed the elastic length-tension curves were not substantially affected by the loading rates used in this study. This suggested the viscous component did not affect the overall passive length-tension curves significantly, this implied a simple musculoskeletal model ignoring the viscous component is sufficient to predict the passive length-tension curves in future studies over the typical loading rated used in the passive testing in this project.

The last study in this thesis examined the intermuscular force transmission between the human medial gastrocnemius muscle and soleus muscle in human in vivo under passive conditions. The results suggested there may be some intermuscular force transmission between these muscles. However, the magnitude remains to be determined and the intermuscular force transmission appeared to be dominated by other sources rather than direct lateral intermuscular force transmission between the muscles.

Cited Works (13)

Year	Entry
1990	Hogan N. Mechanical impedance of single- and multi-articular systems. In: Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990:149-164.
1990	Winter DA. Biomechanics and Motor Control of Human Movement. 2nd ed. New York, NY: Inc., John Wiley & Sons; 1990.
1952	Abbott BC, Aubert XM. The force exerted by active striated muscle during and after change of length. J Physiol. May 28, 1952;117(1):77-86.
1994	Best TM, McElhaney J, Garrett WE, Myers BS. Characterization of the passive responses of live skeletal muscle using the quasi-linear theory of viscoelasticity. J Biomech. April 1994;27(4):413-419.
1994	van den Bogert AJ, Smith GD, Nigg BM. In vivo determination of the anatomical axes of the ankle joint complex: an optimization approach. J Biomech. December 1994;27(12):1477-1488.
2002	Murray WM, Buchanan TS, Delp SL. Scaling of peak moment arms of elbow muscles with upper extremity bone dimensions. J Biomech. January 2002;35(1):19-26.
1971	Huxley AF, Simmons RM. Proposed mechanism of force generation in striated muscle. Nature. October 22, 1971;233(5321):533-538.
1993	Fung YC. Biomechanics: Mechanical Properties of Living Tissues. 2nd ed. New York, NY: Springer-Verlag; 1993.
1969	Isman RE, Inman VT. Anthropometric studies of the human foot and ankle. Bull Prosthet Res. Spring 1969;10-11:97-129.
1990	Alexander RM, Ker RF. The architecture of leg muscles. In: Winters JM, Woo SL-Y, eds. Multiple Muscle Systems: Biomechanics and Movement Organization. New York, NY: Springer-Verlag; 1990:568-577.
1980	Ferry JD. Viscoelastic Properties of Polymers. 3rd ed. New York, NY: John Wiley & Sons; 1980.
1938	Hill AV. The heat of shortening and the dynamic constants of muscle. Proc R Soc Lond B Biol Sci. October 10, 1938;126(843):136-195.
1990	Spoor CW, van Leeuwen JL, Meskers CGM, Titulaer AF, Huson A. Estimation of instantaneous moment arms of lower-leg muscles. J Biomech. 1990;23(12):1247-1259.