Time and frequency domain analysis of electromyogram and sound myogram in the elderly

  • F. Esposito
  • A. Veicsteinas
  • C. Orizio
  • D. Malgrati
Original Article


The aim of this work was to evaluate the influence of the ageing process on the time and frequency domain properties of the surface electrical and mechanical activity of muscle. In 20 healthy elderly subjects (10 men and 10 women, age range 65–78 years) and in 20 young controls, during isometric contractions of the elbow flexors in the 20%–100% range of the maximal voluntary contraction (MVC), estimations were made of the root mean square (rms) and the mean frequency (MF) of the power density spectrum distribution, from the surface electromyogram (EMG) and sound myogram (0SMG) signals, detected at the belly of the biceps brachii muscle. Compared to the young controls, the MVC was lower in the elderly subjects (P < 0.05); at the same %MVC the rms and the MF of EMG and SMG were lower (P < 0.05) in elderly subjects; the rms and MF of the two signals increased as a function of the effort level in all groups. Only in the 80%–100% MVC range did the EMG-MF level off and the SMG-rms decrease; in contrast the young controls, at 80% MVC the high frequency peak in the SMG power spectrum density distribution was not present in the elderly subjects. The results for MVC and %MVC can be related to the reduction in the numbers of muscle fibres in aged subjects. In particular, the lack of fast twitch fibre motor units (MU), attaining high firing rates, might also explain the result at 80% MVC. In 80%–100% MVC range the two signals rms and MF behaviour may have been related to the end of the recruitment of larger MU with high conduction velocity, and to the further increment of MU firing rate in the biceps brachii muscle beyond 80% MVC, respectively. Thus, the coupled analysis of the EMG and SMG with force suggests that in the elderly subjects the reduction of the number of muscle fibres may have co-existed with a MU activation pattern similar to that of the young subjects.

Key words

Muscle sound Surface electromyogram Soundmyogram Isometric exercise Ageing 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Aniansson A, Hedberg M, Henning G-B, Grimby G (1986) Muscle morphology, enzymatic activity, and muscle strength in elderly men: a follow up study. Muscle Nerve 9:585–591Google Scholar
  2. Arendt Nielsen L, Mills KR (1985) The relationship between mean power frequency of the EMG spectrum and muscle fibre conduction velocity. Electroencephalogr Clin Neurophysiol 60:130–134Google Scholar
  3. Barry DT, Geiringer SR, Ball RD (1985) Acoustic myography: a non invasive monitor of motor unit fatigue. Muscle Nerve 8:189–194Google Scholar
  4. Basmajian JV, De Luca CJ (1985) Muscles alive. In: Butler J (ed). Their functions revealed by electromyography. Williams and Wilkins Waverly Press, BaltimoreGoogle Scholar
  5. Bilodeau M, Arsenault AB, Gravel D, Bourbonnais D (1991) EMG power spectra of elbow extensors during ramp and step isometric contractions. Eur J Appl Physiol 63:24–28Google Scholar
  6. Bilodeau M, Arsenault AB, Gravel D, Bourbonnais D (1992) Influence of gender on the EMG power spectrum during an increasing force level. J Electromyogr Kinesiol 121–129Google Scholar
  7. Bilodeau M, Cincera M, Gervais S, Arsenault AB, Gravel D, Lepage Y, McKinley P (1995) Changes in the electromyographic spectrum power distribution caused by a progressive increase in the force level. Eur J Appl Physiol 71:113–123Google Scholar
  8. Bishop CW (1984) Reference values for arm muscle area, arm fat area, subscapular skinfold thickness, and sum of skinfold thickness for American adults. Jpn: J Parenter Enteral Nutr 8:515–522Google Scholar
  9. Borkan GA, Hults DE, Gerzof SG, Robbins AH, Silbert CK (1983) Age changes in body composition revealed by computed tomography. J Gerontol 38:673–677Google Scholar
  10. Brooke MH, Engel WK (1969) The histographic analysis of human muscle biopsies with regard to fiber types. Neurology 19:221–234Google Scholar
  11. Brown WF, Strong MJ, Snow R (1988) Methods for estimating numbers of motor units in biceps-brachialis muscles and losses of motor units with aging. Muscle Nerve 11:423–432Google Scholar
  12. Burke RE (1981) Motor units: anatomy, physiology and functional organization. In: Brookhart JM, Mountcastle VB, Brooks VB, Geiger SR (eds) Handbook of physiology, the nervous system, vol. II. Motor control, 1. American Physiological Society, Bethesda, pp 345–422Google Scholar
  13. de Koning FL, Binkhorst RA, Kauer JMG, Thijnsen HOM (1986) Accuracy of an anthropometric estimate of the muscle and bone area in a transversal cross-section of the arm. Int J Sports Med 7:246–249Google Scholar
  14. Doherty TJ, Vandervoort AA, Taylor AW, Brown WF (1993) Effects of motor unit losses on strength in older men and women. J Appl Physiol 74:868–874Google Scholar
  15. Frontera WR, Hughes VA, Lutz KJ, Evans WJ (1991) A cross-sectional study of muscle strength and mass in 45- to 78-yr old men and women. J Appl Physiol 71:644–650Google Scholar
  16. Gordon G, Holbourn AHS (1948) The sounds from single motor units in a contracting muscle. J Physiol 107:456–464Google Scholar
  17. Grimby G (1988) Physical activity and effects of muscle training in the elderly. Ann Clin Res 20:62–66Google Scholar
  18. Grimby G, Danneskiold-Samsoe B, Hvid K, Saltin D (1982) Morphology and enzymatic capacity in arm and leg muscles in 78–81 year old men and women. Acta Physiol Scand 115:125–134Google Scholar
  19. Howard JE, McGill KC, Dorfman LJ (1988) Age effects on properties of motor unit action potentials: ADEMG analysis. Annu Neurol 24:207–213Google Scholar
  20. Ikai M, Fukunaga T (1970) A study of training effect on strength per unit cross-sectional area of muscle by means of ultrasonic measurement. Int Z Angew Physiol 28:172Google Scholar
  21. Jorgensen F, Lammert O (1976) Accelerometermyography (AMG) II. Contribution of motor unit. In: Komi P (ed) Biomechanics University Park Press, Balitmore, pp 159–164Google Scholar
  22. Keidel M, Keidel WD (1989) The computer-vibromyography as a biometric progress in studying muscle function. Biomed. Technik 34:107–116Google Scholar
  23. Klitgaard H, Mantoni M, Schiaffino S, Ausoni S, Gorza L, Laurent-Winter C, Schnohr P, Saltin B (1990) Function, morphology and protein expression of ageing skeletal muscle: a cross-sectional study of elderly men with different training backgrounds. Acta Physiol Scand 140:41–54Google Scholar
  24. Kukulka CG, Clamann HP (1981) Comparison of the recruitment and discharge properties of motor units in human brachial biceps and adductor pollicis during isometric contractions. Brain Res 219:45–55Google Scholar
  25. Larsson L, Grimby G, Karlsson J (1979) Muscle strength and speed of movement in relation to age and muscle morphology. J Appl Physiol 46:451–456Google Scholar
  26. Lexell J, Henriksson-Larsen K, Winblad B, Sjostrom M (1983) Distribution of different fiber types in human skeletal muscles:effects of aging studied in whole muscle cross sections. Muscle Nerve 6:588–595Google Scholar
  27. Merletti R, Lo Conte LR, Cisari C, Actis MV (1992) Age related changes in surface myoelectric signals. Scand J Rehabil Med 24:25–36Google Scholar
  28. Orizio C (1993) Muscle sound: bases for the introduction of a mechanomyographic signal in muscle studies. Crit Rev Biomed Eng 21:201–243Google Scholar
  29. Orizio C, Perini R, Veicsteinas A (1989) Muscular sound and force relationship during isometric contraction in man. Eur J Appl Physiol 58:528–533Google Scholar
  30. Orizio C, Perini R, Diemont B, Maranzana Figini M, Veicsteinas A (1990) Spectral analysis of muscular sound during isometric contraction of biceps brachii. J Appl Physiol 68:508–512Google Scholar
  31. Orizio C, Perini R, Diemont B, Veicsteinas A (1992) Muscle sound and electromyogram spectrum analysis during exhausting contractions in man. Eur J Appl Physiol 65:1–7Google Scholar
  32. Orizio C, Solomonow M, Baratta RV, Veicsteinas A (1993) Influence of motor units recruitment and firing rate on the soundmyogram and EMG characteristics in cat gastrocnemius. J Electromyogr Kinesiol 4:232–241Google Scholar
  33. Orizio C, Esposito F, Veicsteinas A (1994) Effect of acclimatization to high altitude (5050 m) on motor unit activation pattern and muscle performance. J Appl Physiol 77:2840–2844Google Scholar
  34. Oster G (1984) Muscle sounds. Sci Am 250:108–114Google Scholar
  35. Sadoyama T, Masuda T, Miyata H, Katsuta S (1988) Fibre conduction velocity and fibre composition in human vastus lateralis. Eur J Appl Physiol 57:767–771Google Scholar
  36. Sanchez JH, Solomonov M, Baratta RV, D'Ambrosia R (1993) Control strategies of the elbow antagonist muscle pair during two types of increasing isometric contractions. J Electromyogr Kinesiol 3:33–40Google Scholar
  37. Zhang YT, Frank CB, Rangayan RM, Bell GD (1992) A comparative study of simultaneous vibromyography and electromyography with active human quadriceps. IEEE Trans Biomed Eng 39:1045–1052Google Scholar

Copyright information

© Springer-Verlag 1996

Authors and Affiliations

  • F. Esposito
    • 1
  • A. Veicsteinas
    • 1
  • C. Orizio
    • 1
  • D. Malgrati
    • 2
  1. 1.Cattedra di Fisiologia Umana, Dipartimento di Scienze Biomediche e BiotecnologieUniversity of BresciaBresciaItaly
  2. 2.Casa di Riabilitazione e Cura “Domus Salutis”BresciaItaly

Personalised recommendations