Summary
A muscle model is described that uses electromyogram (EMG), muscle length and speed of contraction to predict muscle force. Physiological parameters are the Hill constants and the shape of the twitch reponse to a single stimulus. The model was incorporated in a jaw model of the rabbit and tested by predicting the bite force produced by the jaw muscles during mastication. The time course of the calculated force appeared to match the bite force, measured in vivo by a strain gauge, applied to the bone below the teeth. The variation in peak strain amplitude from cycle to cycle correlated with the variation predicted by the model. The peak amplitude of the integrated EMGs of individual jaw muscles showed an average correlation with peak strain of 0.41. Use of the sum of the available peak amplitudes, weighted according to their effect upon the bite force increased the correlation to 0.46; the model predicted bite forces showed a correlation of 0.57 with the strain. The increase in correlation was statistically significant. The muscle forces were calculated using a minimum number of easily obtainable constants.
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References
Anapol FC, Muhl ZF, Fuller JH (1987) The force-velocity relation of the rabbit digastric muscle. Arch Oral Biol 32:93–99
Armstrong RB, Laughlin MH (1985) Metabolic indicators of fibre recruitment in mammalian muscles during locomotion. J Exp Biol 115:201–213
Basmajian JV, de Luca CJ (1985) Muscle alive. Their functions revealed by electromyography. Williams and Wilkins, Baltimore
Dixon WJ, Massey FJ (1969) Introduction to statistical analysis. McGraw-Hill, New York
Dowling JJ, Norman RW (1988) The prediction of individual muscle forces at the human elbow. In: De Groot G, Hollander AP, Huijing PA, van Ingen Schenau GJ (eds) Biomechanics XI-A. Free University Press, Amsterdam
Hagberg C (1986) The amplitude distribution of electromyographic activity of mastication muscles during unilateral chewing. J Oral Rehabil 13:567–574
Hill AV (1938) The heat of shortening and the dynamic constants of muscle. Proc R Soc Lond [Biol] B76:136–195
Hof AL, van den Berg JW (1981) EMG to force processing III: estimation of model parameters for the human triceps surae and assessment of the accuracy by means of a torque plate. J Biomech 14:771–785
Hylander WL, Johnson KR, Crompton AW (1987) Loading patterns and jaw movements during mastication in Macaca fascicularis: a bone strain, electromyographic, and cineradiographic analysis. Am J Phys Anthropol 72:287–314
van Ingen Schenau GJ, Bobbert MF, Ettema GJ, de Graaf JB, Huijing PA (1988) A simulation of rat EDL force output based on intrinsic muscle properties. J Biomech 21:815–824
Inman VT, Ralston JB, Sanders CM, Feinstein B, Wright EW (1952) Relation of human electromyogram to muscular tension. Electroencephalogr Clin Neurophysiol 4:187–194
Lippold OCJ (1952) The relation between integrated action potentials in a human muscle and its isometric tension. J Physiol 117:492–499
Muhl ZF (1982) Active length tension relation and the effect of muscle pinnation on fiber lengthening. J Morphol 173:285–292
Muhl ZF, Grimm AF, Glick PL (1978) Physiological and histological measurements of rabbit digastric muscle. Arch Oral Biol 23:1051–1059
Olney SJ, Winter DA (1985) Predictions of knee and ankle moments of force in walking from EMG and kinematic data. J Biomech 18:9–20
Otten E (1987) A myocybernetic model of the jaw system of the rat. J Neurosci Methods 21:287–302
Phillips CA, Petrofski JS (1983) Velocity of contraction of skeletal muscle as a function of activation and fiber composition: a mathematical model. J Biomech 13:549–558
Ralston HJ (1961) Uses and limitations of electromyography in the quantitative study of muscle function. Am J Orthod 47:521–530
Schwarz G, Enomoto S, Valiquette C, Lund P (1989) Mastication in the rabbit: a description of movement and muscle activity. J Neurophysiol 62:273–287
Weijs WA, de Jongh HJ (1977) Strain in mandibular alveolar bone during mastication in the rabbit. Arch Oral Biol 22:667–675
Weijs WA, van der Wielen-Drent TK (1982) The relationship between sarcomere length and activation pattern in the rabbit masseter muscle. Arch Oral Biol 28:307–315
Weijs WA, van der Wielen-Drent TK (1983) Sarcomere length and EMG-activity in some jaw muscles of the rabbit. Acta Anal 113:178–188
Weijs WA, van Ruijven LJ (1990) Models of masticatory mechanics: their reliability, resolving power and usefulness in functional morphology. Neth J Zool 40:136–152
Weijs WA, Brugman P, Klok EM (1987) The growth of the skull and jaw muscles and its functional consequences in the New Zealand rabbit (Oryctolagus cuniculus L.). J Morphol 194:143–161
Weijs WA, Korfage JAM, Langenbach GJ (1989a) The functional significance of the position of the center of rotation for jaw opening and closing in the rabbit. J Anat 162:133–148
Weijs WA, Brugman P, Grimbergen CA (1989b) Jaw movements and muscle activity during mastication in growing rabbits. Anal Rec 224:407–416
Winters JM, Stark L (1987) Muscle models: what is gained and what is lost by varying model complexity. Biol Cybern 55:403–420
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van Ruijven, L.J., Weijs, W.A. A new model for calculating muscle forces from electromyograms. Europ. J. Appl. Physiol. 61, 479–485 (1990). https://doi.org/10.1007/BF00236071
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DOI: https://doi.org/10.1007/BF00236071