Skip to main content
Log in

Relationship between force and integrated EMG activity during voluntary isometric anisotonic contraction

  • Published:
European Journal of Applied Physiology and Occupational Physiology Aims and scope Submit manuscript

Summary

The surface electromyogram (EMG) was recorded for the extensor carpi radiales of normal human subjects during voluntary isometric anisotonic contractions as well as the force generated by the muscle. The relationship between force and instantaneous integrated EMG could not be fitted by a single linear function or a parabola.

The muscle was then considered as a system (a) presenting a maximum force and (b) in which the EMG activity represented the input and the contraction force the output, that is F=f(iEMG) and not, as is usually done, iEMG=f(F). In addition the summed iEMG from the beginning of the contraction was used since the actual force depends on all preceding events. These findings led to testing for a non-linear and asymptotic function relating F to iEMG. A double exponential function:

$$F = a[1 - \exp {\text{ (}} - b\sum \Delta iEMG)] + d[1 - \exp {\text{ }}( - c\sum \Delta iEMG)]$$

could account for the two mechanisms by which the force of a voluntary contraction is increased.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  • Adrian ED, Bronk DW (1929) The discharge of impulse in motor nerve fibers, part II. J Physiol 67: 119–151

    Google Scholar 

  • Aubert X (1956) Le couplage energétique de la contraction musculaire. Editions Arscia, Brussels

    Google Scholar 

  • Basmajian JV (1974) Muscles alive. 3rd edn. Williams & Wilkins Co., Baltimore

    Google Scholar 

  • Bottomley A, Kinnier Wilson AB, Nightingale A (1963) Muscle substitutes and myoelectric control. J Br Inst Radio Eng 26: 439–448

    Google Scholar 

  • Bouisset S (1973) EMG and muscle force in normal motor activities. In: Desmedt JE (ed) New developments in electromyography and clinical neurophysiology, vol 1. Karger, Basel, pp 547–583

    Google Scholar 

  • Brandstater ME, Lambert EH (1973) Motor unit anatomy. In: Desmedt JE (ed) New developments in electromyography and clinical neurophysiology, vol 1. Karger, Basel, pp 14–22

    Google Scholar 

  • Buchthal F, Erminio F, Rosenfalk P (1959) Motor unit territory in different human muscles. Acta Physiol Scand 45: 72–87

    Google Scholar 

  • Burke RE, Levine DN, Tsairis P, Zajac FE (1973) Physiological types and histochemical profiles in motor units of the cat gastrocnemius. J Physiol 234: 723–749

    Google Scholar 

  • Clamann HP, Gillies JD, Skinner RD, Henneman E (1974) Quantitative measures of output of a motoneuron pool during monosynaptic reflexes. J Neurophysiol 37: 1328–1337

    Google Scholar 

  • Close R (1967) Properties of motor units in fast and slow skeletal muscles of the rat. J Physiol 193: 45–55

    Google Scholar 

  • De Luca CJ (1979) Physiology and mathematics of myoelectric signals. IEEE Trans Biomed Eng, BME-26: 313–325

    Google Scholar 

  • De Vries HA (1968) “Efficiency of electrical activity” as a physiological measure of the functional state of muscle tissue. Am J Phys Med 47: 10–22

    Google Scholar 

  • Freund HJ, Budingen HJ, Dietz V (1975) Activity of single motor units from human forerarm muscles during voluntary isometric contractions. J Neurophysiol 38: 933–946

    Google Scholar 

  • Gillies JD (1972) Motor unit discharge patterns during isometric contraction in man. J Physiol 223: 36P-37P

    Google Scholar 

  • Gordon AM, Huxley AF, Julien FJ (1964) The length-tension diagram of single vertebrate striated muscle fibers. J Physiol 171: 28P-30P

    Google Scholar 

  • Grillner S, Udo M (1971) Recruitment in the tonic stratch reflex. Acta Physiol Scand 81: 571–573

    Google Scholar 

  • Inman VT, Ralston HJ, Saunders JB de CM, Feinstein B, Wright EW Jr (1952) Relation of human electromyogram to muscular tension. EEG Clin Neurophysiol 4: 187–194

    Google Scholar 

  • Kernell D (1966) The repetitive discharge of motoneurones in muscular afferents and motor control. In: Granit R (ed) Nobel symposium. Almquist and Wiksell, Stockholm, pp 351–362

    Google Scholar 

  • Komi PV, Viitasalo JHT (1976) Signal characteristics of EMG at different levels of muscle tension. Acta Physiol Scand 96: 267–376

    Google Scholar 

  • Kuroda E, Klissouras V, Milsum JH (1970) Electrical and metabolic activities and fatigue in human isometric contraction. J Appl Physiol 29: 358–367

    Google Scholar 

  • Lind AR, Petrofsky JS (1979) Amplitude of the surface electromyogram during fatiguing isometric contractions. Muscle Nerve 2: 257–264

    Google Scholar 

  • Lippold OCJ (1952) The relation between integrated action potentials in a human muscle and its isometric tension. J Physiol 117: 492–499

    Google Scholar 

  • Mac Phedran AM, Wuerker RB, Henneman E (1965) Properties of motor units in a homogenous red muscle (soleus) of the cat. J Neurophysiol 28: 71–84

    Google Scholar 

  • Maton B (1973) Influence du temps d'intégration sur la relation entre l'EMG de surface intégré et la force au cours de la contraction isométrique, isotonique. Electromyogr Clin Neurophysiol 13: 307–318

    Google Scholar 

  • Maton B (1977) Fréquence et recrutement des unités motrices du muscle biceps brachial au cours du travail statique chez l'homme normal. J Physiol (Paris) 73: 177–199

    Google Scholar 

  • Maton B, Bouisset S, Métral S (1969) Vomparaison des activités électromyographiques globale et élémentaire au cours de la contraction volontaire. Electromyography 9: 311–323

    Google Scholar 

  • Métral S, Lemaire C, Monod H (1974) Force length integrated EMG relationships for submaximal isometric contractions. In: The control of upper extremity of prothesis and orthesis. CC Thomas, Springfield, IL, pp 13–22

    Google Scholar 

  • Milner-Brown HS, Stein RB (1975) The relation between the surface electromyogram and muscular force. J Physiol 246: 549–570

    Google Scholar 

  • Milner-Brown HS, Stein RB, Yemm R (1973a). The orderly recruitment of human motor units during voluntary isometric contraction. J Physiol 230: 359–370

    Google Scholar 

  • Milner-Brown HS, Stein RB, Yemm R (1973b) Changes in firing rate of human motor units during linearly changing voluntary contractions. J Physiol 230: 371–391

    Google Scholar 

  • Moritani T, De Vries HA (1978) Reexamination of the relationship between the surface integrated electromyogram (IEMG) and force of isometric contraction. Am J Phys Med 57: 263–277

    Google Scholar 

  • Olson CB, Carpenter DO, Henneman E (1968) Orderly recruitment of muscle action potentials. Arch Neurol 19: 591–597

    Google Scholar 

  • Pertuzon E (1971) Relation force-longueur isométrique du muscle humain en contraction maximale. CR Soc Biol 165: 328

    Google Scholar 

  • Pertuzon E (1972) La contraction musculaire dans le mouvement volontaire maximal. Thèse Doctorat d'Etat, Lille, p 210

  • Petrofsky JS, Lind AR (1978) Metabolic, cardiovascular, and respiratory factors in the development of fatique in lifting tasks. Am Physiol Soc 45: 64–68

    Google Scholar 

  • Rack PMH, Westbury DR (1969) The effects of length and stimulus rate on tension in the isometric cat soleus muscle. J Physiol 204: 443–460

    Google Scholar 

  • Scherrer J, Bourguignon A (1959) Changes in electromyogram produced by fatigue in man. Am J Phys Med 38: 170–180

    Google Scholar 

  • Scherrer J, Monod H (1960) Le travail musculaire local et la fatigue chez l'homme. J Physiol (Paris) 52: 419–501

    Google Scholar 

  • Stephens JA, Taylor A (1972) Fatigue and maintained voluntary muscle contraction in man. J Physiol 220: 1–18

    Google Scholar 

  • Tanji J, Kato M (1973a) Firing rate of individual motor units in voluntary contraction of abductor digiti minimi muscle in man. Exp Neurol 40: 771–784

    Google Scholar 

  • Tanji J, Kato M (1973b) Recruitment of motor units in voluntary contraction of a finger muscle in man. Exp Neurol 40: 750–770

    Google Scholar 

  • Tournay A, Paillard J (1953) Electromyographie des muscles radiaux à l'état normal. Rev Neurol 89: 277–279

    Google Scholar 

  • Vredenbregt J, Rau G (1973) Surface electromyography in relation to force, muscle length and endurance. In: Desmedt JE (ed) New developments in electromyography and clinical neurophysiology, vol 1. Karger, Basel, pp 607–622

    Google Scholar 

  • Zuniga EN, Simons DG (1969) Nonlinear relationship between averaged EMG potential and muscle tension in normal subjects. Arch Phys Med Rehab 50: 613–620

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Additional information

This work was supported by grants from the Délégation Générale à la Recherche Scientifique et Technique, No 74 70836

Rights and permissions

Reprints and permissions

About this article

Cite this article

Metral, S., Cassar, G. Relationship between force and integrated EMG activity during voluntary isometric anisotonic contraction. Europ. J. Appl. Physiol. 46, 185–198 (1981). https://doi.org/10.1007/BF00428870

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00428870

Key words

Navigation