A possible means of quantifying the surface electromyographic (EMG) signal is to try to relate it to the sarcomere length of the muscle, which is a function of muscle tension. The present work deals with the measurement of sarcomere length in human muscles. Sarcomere length is measured by using a thin sheet of muscle as a diffraction grating and obtaining and photographing its diffraction pattern using a modified light microscope. Samples of human muscle are available only from cadavers in the anatomical position, so a procedure for prediction of sarcomere length at other positions is described. The limitations of working with cadavaric tissue are outlined and discussed, and, for the readers unfamiliar with the structure and physiology of striated muscle, a brief description of this is given.
BendallJ. R. (1973) Postmortem changes in muscle, In The structure and function of muscle, II, 2nd Edition (Edited by BourneG. H.), Academic Press, London.
3.
CuttsA. (1986) Sarcomere length changes in the wing muscles during the wing beat cycle of two bird species, J. Zool., 209, 183–185.
4.
DimeryN. J. (1984) Mechanics of the leg muscles of rabbits (Oryctolagus cuniculus (L) and other mammals, PhD thesis, University of Leeds.
5.
DimeryN. J. (1985) Muscle and sarcomere lengths in the hind limb of a rabbit (Oryctolagus cuniculus) during a galloping stride, J. Zool., 205, 373–383.
6.
EdmanK. A. P.ElzingaG.NobleM. I. M. (1978) Enhancement of mechanical performance by stretch during tetanic contractions of vertebrate skeletal muscle fibres, J. Physiol., 205, 131–145.
7.
EdmanK. A. P.FlitneyF. W. (1982) Laser diffraction studies of sarcomere dynamics during isometric relaxation in isolated muscle fibres of the frog, J. Physiol., 329, 1–21.
8.
EdmanK. A. P.ReggianiC. (1983) The descending limb of the length-tension relation studied in short, length clamped segments of frog muscle fibres, J. Physiol., 341, 41–42.
9.
EdmanK. A. P.ReggianiC. (1984a) The absence of the plateau of the sarcomere length tension relation in frog muscle fibres, Act. Physiol. Scand., 122, 213–216.
10.
EdmanK. A. P.ReggianiC. (1984b) The sarcomere length tension relation of frog skeletal muscle has no plateau, J. Physiol., 353, 62.
11.
EdmanK. A. P.ReggianiC. (1984c) Redistribution of sarcomere length during isometric contraction of frog muscle fibres and its relation to tension creep, J. Physiol., 351, 169–198.
12.
GordonA. M.HuxleyA. F.JulianF. J. (1966) The variation in isometric tension with sarcomere length in vertebrate muscle fibres, J. Physiol., 184, 170–192.
13.
HertzbergS. R.MuhlZ. F.BegoleE. A. (1980) Muscle sarcomere length following passive jaw opening in the rabbit, Anat. Rec., 197, 435–440.
14.
HomsherE.IrvingM.LebacqJ. (1983) The variation in shortening heat with sarcomere length in frog muscle, J. Physiol., 345, 107–121.
15.
HoutzS. J.FischerF. J. (1959) An analysis of muscle action and joint excursion on a stationary bicycle, J. Bone Jt. Surg., 41A, 123–131.
16.
HuxleyA. F.NiedergerkeR. (1954) Structural changes in muscle during contraction. Interference microscopy of living muscle fibres, Nature, 173, 971–973.
17.
HuxleyH. E. (1969) The mechanism of muscular contraction, Science, 164, 1356–1366.
18.
HuxleyH. E. (1971) The structural basis of muscular contraction, Proc. R. Soc. B., 178, 131–149.
19.
HuxleyH. E.HansonJ. (1954) Changes in the cross striations of muscle during contraction and stretch and their interpretation, Nature, 173, 973–976.
20.
IsmailH. M.RanatungaK. W. (1978) Isometric tension development in human skeletal muscle in relation to its working range of movement: The length tension relation of the biceps brachii muscle, Expl. Neurol., 62, 595–604.
21.
IwazumiT.PollackG. H. (1979) Online measurement of sarcomere length from diffraction patterns in muscle, IEEE BME, 26, 86–93.
22.
JensenR. H.DavyD. T. (1975) An investigation of muscle lines of action about the hip; a centroid line approach vs. the straight line approach, J. Biomech., 8, 103–110.
23.
KeynesR. D.AidleyD. J. (1981) Nerve and muscle, Cambridge University Press.
24.
MillP. J. (1982) Comparative Neurobiology, Edward Arnold, London.
25.
MuhlZ. F.GrimmA. F.GlickP. L. (1978) Physiologic and histologic measurements of the rabbit digastric muscle, Archs Oral. Biol., 23, 1051–1059.
NordstromS. H.BishopM.YemmR. (1974) The effect of jaw opening on the sarcomere length of the masseter and temporal muscles of the rat, Arch Oral. Biol.19, 151–156.
28.
NordstromS. H.YemmR. (1972) Sarcomere length in the masseter muscles of the rat, Archs Oral. Biol., 17, 895–902.
29.
PennycuickC. J.RezendeM. A. (1984) The specific power output of aerobic muscle, related to power density of mitochondria, J. Expl. Biol., 108, 377–392.
30.
RackP. M. H.WestburyD. R. (1969) The effects of length and stimulus rate on tension in the isometric cat soleus muscle, J. Physiol., 204, 443–460.
31.
RayneJ.CrawfordG. N. C. (1972) The relationship between fibre length, muscle excursion and jaw movement in the rat, Archs Oral. Biol., 17, 859–872.
32.
RudelR.FerencyZite F. (1979) Do laser diffraction studies on striated muscle indicate stepwise sarcomere shortening? Nature, 278, 573–575.
33.
RudelR.FerenczyZite F. (1980) Efficiency of light diffraction by cross-striated muscle fibres under stretch and during isometric contraction, Biophys. J., 30, 507–516.
34.
WalkerS. M.ShrodtG. R. (1973) I segment lengths and thin filament periods in skeletal muscle fibres of the Rhesus monkey and human, Anat. Rec., 178, 63–82.
35.
WeijsW. A.Van der Weilen DrentT. K. (1982) Sarcomere length and electromyographic activity in some jaw muscles of the rabbit, Acta, Anat., 113, 178–188.
36.
WhiteD. C. S. (1970) Rigor contraction and the effect of various phosphate compounds on glycerinated insect flight and vertebrate muscle, J. Physiol., 208, 583–605.
