Advertisement

Biological Cybernetics

, Volume 67, Issue 2, pp 143–153 | Cite as

Detection of motor unit action potentials with surface electrodes: influence of electrode size and spacing

  • Andrew J. Fuglevand
  • David A. Winter
  • Aftab E. Patla
  • Daniel Stashuk
Article

Abstract

A model of the motor unit action potential was developed to investigate the amplitude and frequency spectrum contributions of motor units, located at various depths within muscle, to the surface detected electromyographic (EMG) signal. A dipole representation of the transmembrane current in a three-dimensional muscle volume was used to estimate detected individual muscle fiber action potentials. The effects of anisotropic muscle conductance, innervation zone location, propagation velocity, fiber length, electrode area, and electrode configuration were included in the fiber action potential model. A motor unit action potential was assumed to be the sum of the individual muscle fiber action potentials. A computational procedure, based on the notion of isopotential layers, was developed which substantially reduced the calculation time required to estimate motor unit action potentials. The simulations indicated that: 1) only those motor units with muscle fibers located within 10–12 mm of the electrodes would contribute significant signal energy to the surface EMG, 2) variation in surface area of electrodes has little effect on the detection depth of motor unit action potentials, 3) increased interelectrode spacing moderately increases detection depth, and 4) the frequency content of action potentials decreases steeply with increased electrode-motor unit territory distance.

Keywords

Motor Unit Electrode Configuration Muscle Volume Unit Territory Motor Unit Action Potential 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Albers BA, Put JHM, Wallinga W, Wirtz P (1989) Quantitative analysis of single muscle fiber action potentials recorded at known distances. Electroencephalogr Clin Neurophysiol 73:245–253Google Scholar
  2. Andreassen S, Arendt-Nielsen L (1987) Muscle fiber conduction velocity in motor units of the human anterior tibial muscle: a new size principle parameter. J Physiol (Lond) 391:561–571Google Scholar
  3. Andreassen S, Rosenfalck A (1978) Recording from a single motor unit during strong effort. IEEE Trans Biomed Eng 25:501–508Google Scholar
  4. Andreassen S, Rosenfalck A (1981) Relationship of intracellular and extracellular action potentials of skeletal muscle fibers. CRC Crit Rev Bioeng 6:267–306Google Scholar
  5. Armstrong JB, Rose PK, Vanner S, Bakker GJ, Richmond FJR (1988) Compartmentalization of motor units in the cat neck muscle, biventer cervicis. J Neurophysiol 60:21–44Google Scholar
  6. Basmajian JV, (1973) Electrodes and electrode connectors. In: Desmedt JE (eds) New developments in electromyography and clinical neurophysiology, Karger, Basel, pp 502–510Google Scholar
  7. Basmajian JV, De Luca CJ (1985) Muscles alive: their functions revealed by electromyography, 5th edn. Williams & Wilkins, BaltimoreGoogle Scholar
  8. Bodine SC, Roy RR, Eldred E, Edgerton VR (1987) Maximal force as a function of anatomical features of motor units in the cat tibialis anterior. J Neurophysiol 57:1730–1745Google Scholar
  9. Boyd DC, Lawrence PD, Bratty PJA (1978) On modeling the single motor unit action potential. IEEE Trans Biomed Eng 25:236–243Google Scholar
  10. Brook MH, Engel WK (1969) The histographic analysis of human muscle biopsies with regard to fiber types. Neurology 19:221–223Google Scholar
  11. Buchthal F, Guld C, Rosenfalck P (1955) Propagation velocity in electrically activated muscle fibres in man. Acta Physiol Scand 34:75–89Google Scholar
  12. Buchthal F, Guld C, Rosenfalck P (1957) Multielectrode study of the territory of a motor unit. Acta Physiol Scand 39:83–104Google Scholar
  13. Burke RE (1981) Motor units: anatomy, physiology, and functional organization. In: Brooks VB (eds) Handbook of physiology, sect 1, vol II/1. American Physiological Society, Washington DC, pp 345–422Google Scholar
  14. De Luca CJ, Merletti R (1988) Surface myoelectric signal cross-talk among muscles of the leg. Electroencephalogr Clin Neurophysiol 69:568–575Google Scholar
  15. Dimitrova N (1974) Model of the extracellular potential field of a single striated muscle fibre. Electromyogr Clin Neurophysiol 14:53–66Google Scholar
  16. Ekstedt J (1964) Human single muscle fiber action potentials. Acta Physiol Scand [Suppl] 61:1–96Google Scholar
  17. Ekstedt J, Stålberg E (1973) How the size of needle electrode leading-off surface influences the shape of the single muscle fibre action potential in electromyography. Comput Programs Biomed 3:204–212Google Scholar
  18. Fleischer SM, Studer RM, Moschytz GS (1984) Mathematical model of single-fiber action potential. Med Biol Eng Comput 22:433–439Google Scholar
  19. Fuglevand AJ (1989) A motor unit pool model: relationship of neural ontrol properties to isometric muscle tension and the electromyogram. Ph. D. thesis, University of Waterloo, CanadaGoogle Scholar
  20. Gath I, Stålberg E (1975) Frequency and time domain characteristics of single muscle fibre action potentials. Electroencephalogr Clin Neurophysiol 39:371–376Google Scholar
  21. Gath I, Stålberg E (1977) On the volume conduction in human skeletal muscle: in situ measurements. Electroencephalogr Clin Neurophysiol 43:106–110Google Scholar
  22. Gath I, Stålberg E (1978) The calculated radial decline of the extracellular action potential compared with in situ measurements in the human brachial biceps. Electroencephalogr Clin Neurophysiol 44:547–552Google Scholar
  23. Geddes LA, Baker LE (1967) The specific resistance of biological material — a compendium of data for the biomedical engineer and physiologist. Med Biol Eng 5:271–293Google Scholar
  24. George RE (1970) The summation of muscle fibre action potentials. Med Biol Eng 8:357–365Google Scholar
  25. Gootzen THJ, Stageman DF, Van Oostrerom A (1991) Finite limb dimensions and finite muscle length in a model for the generation of electromyographic signals. Electroencephalogr Clin Neurophysiol 81:152–162Google Scholar
  26. Griep PAM, Boon KL, Stegeman DF (1978) A study of the motor unit action potential by means of computer simulation. Biol Cybern 30:221–230Google Scholar
  27. Grieve DW (1975) Electromyography. In: Grieve DW, Miller DI, Paul JP, Smith AJ (eds) Techniques for the analysis of human movement. Lepus, London, pp 109–149Google Scholar
  28. Gydikov A, Trayanova N (1986) Extracellular potentials of single active muscle fibres: effects of finite fibre length. Biol Cybern 53:363–372Google Scholar
  29. Gydikov A, Gerilovsky L, Radicheva N, Trayanova N (1986) Influence of the muscle fibre and geometry on the extracellular potentials. Biol Cybern 54:1–8Google Scholar
  30. Hary D, Belman MJ, Propst J, Lewis S (1982) A statistical analysis of the spectral moments used in EMG tests of endurance. J Appl Physiol 53:779–783Google Scholar
  31. Inbar GF, Allin J, Kranz H (1987) Surface EMG spectral changes with muscle length. Med Biol Eng Comput 25:683–689Google Scholar
  32. Knaflitz M, Merletti R, De Luca CJ (1990) Inference of motor unit recruitment order in voluntary and electrically elicited contractions. J Appl Physiol 68:1657–1667Google Scholar
  33. Lindström L, Magnusson RI (1977) Interpretation of myoelectric power spectra: a model and its applications. Proc IEEE 65:653–662Google Scholar
  34. Loeb GE, Gans C (1986) Electromyography for experimentalists. Univ Chicago Press, ChicagoGoogle Scholar
  35. Lorente de Nó R (1947) A study of nerve physiology, chap XVI. Analysis of the distribution of action currents of nerve in volume conductors. Stud Rockefellar Inst Med Res 132:384–477Google Scholar
  36. Ludin HP (1969) Microelectrode study of normal human skeletal muscle. Eur Neurol 2:340–358Google Scholar
  37. Lynn PA, Bettles ND, Hughes AD, Johnson SW (1978) Influences of electrode geometry on bipolar recordings of the surface electromyogram. Med Biol Eng Comput 16:651–660Google Scholar
  38. McGill KC, Huynh A (1988) A model of the surface-recorded motor-unit action potential. Proc IEEE Eng Med Biol Soc 10:1697–1699Google Scholar
  39. Milner-Brown HS, Stein RB (1975) The relation between the surface electromyogram and muscular force. J Physiol (Lond) 246:549–569Google Scholar
  40. Milner-Brown HS, Stein RB, Yemm R (1973) The contractile properties of human motor units during voluntary isometric contractions. J Physiol (Lond) 228:285–306Google Scholar
  41. Morrenhof JW, Abbink HJ (1985) Crosscorrelation and cross-talk in surface electromyography. Electromyogr Clin Neurophysiol 25:73–79Google Scholar
  42. Nandedkar S, Stålberg E (1983) Simulation of macro EMG motor unit potentials. Electroenceph Clin Neurophysiol 56:52–62Google Scholar
  43. Nandedkar SD, Sanders DB, Stålberg EV (1985) Selectivity of electromyographic recording techniques: a simulation study. Med Biol Eng Comput 23:536–540Google Scholar
  44. Nandedkar SD, Sanders DB, Stålberg EV (1986) Simulation and analysis of the electromyographic interference pattern in normal muscle. Part I: turns and amplitude measurements. Muscle Nerve 9:423–430Google Scholar
  45. Nandekar SD, Stålberg EV, Sanders DB (1985) Simulation techniques in electromyography. IEEE Trans Biomed Eng 32:775–785Google Scholar
  46. Parker PA, Scott RN (1973) Statistics of the myoelectric signal from monopolar and bipolar electrodes. Med Biol Eng 11:591–596Google Scholar
  47. Plonsey R (1964) Volume conductor fields of action currents. Biophys J 4:317–328Google Scholar
  48. Plonsey R (1974) The active fiber in a volume conductor. IEEE Trans Biomed Eng 21:371–381Google Scholar
  49. Plonsey R (1977) Action potential sources and their volume conductor fields. Proc IEEE 65:601–611Google Scholar
  50. Rosenfalck P (1969) Intraand extracellular potential fields of active nerve and muscle fibers. Acta Physiol Scand [Suppl] 47:239–246Google Scholar
  51. Stålberg E (1966) Propagation velocity in human muscle fibers in situ. Acta Physiol Scand [Suppl] 70:1–112Google Scholar
  52. Stålberg E, Antoni L (1980) Electrophysiological cross section of the motor unit. J Neurol Neurosurg Psych 43:469–474Google Scholar
  53. Winter DA (1990) Biomechanics and motor control of human movement. Wiley, New YorkGoogle Scholar
  54. Zipp P (1978) Effect of electrode parameters on the bandwidth of the surface e.m.g. power spectrum. Med Biol Eng Comput 16:537–541Google Scholar

Copyright information

© Springer-Verlag 1992

Authors and Affiliations

  • Andrew J. Fuglevand
    • 1
  • David A. Winter
    • 1
    • 2
  • Aftab E. Patla
    • 1
  • Daniel Stashuk
    • 2
  1. 1.Department of KinesiologyUniversity of WaterlooWaterlooCanada
  2. 2.Department of Systems Design EngineeringUniversity of WaterlooWaterlooCanada

Personalised recommendations