Skip to main content
Log in

Physiological effects of micropauses in isometric handgrip exercise

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

Summary

The physiological response to continuous and intermittent handgrip exercise was evaluated. Three experiments were performed until exhaustion at 25% of maximal voluntary contraction (MVC): experiment 1, continuous handgrip (CH) (n = 8); experiment 2, intermittent handgrip with 10-s rest pause every 3 min (IH) (n=8); and experiment 3, as IH but with electrical stimulation (ES) of the forearm extensors in the pauses (IHES) (n=4). Before, during, and after exercise, recordings were made of heart rate (HR), arterial blood pressure (BP), exercising forearm blood flow, and concentrations of potassium [K+] and lactate [La] in venous blood from both arms. The electromyogram (EMG) of the exercising forearm extensors and perceived exertion were monitored during exercise. Before and up to 24 h after exercise, observations were made of MVC, of force response to electrical stimulation and of the EMG response to a 10-s test contraction (handgrip) at 25% of the initial MVC. Maximal endurance time (t tim) was significantly longer in IH (23.1 min) than in CH (16.2 min). The ES had no significant effect ont lim. During exercise, no significant differences were seen between CH and IH in blood flow, venous [K+] and [La], or EMG response. The HR and BP increased at the same rate in CH and IH but, because of the longer duration of IH, the levels at exhaustion were higher in this protocol. The subjects reported less subjective fatigue in IH. During recovery, return to normal MVC was slower after CH (24 h) than after IH (4 h). However, the frequency content of the EMG during the 10-s test contractions was still reduced 24 h after IH, but only 4 h after CH. This may be explained by the larger amount of potassium lost up to the first hour of recovery in IH. None of the measured physiological parameters could provide a satisfactory explanation, either of the 43% difference int lim between CH and IH, or of the sense of relief reported by all subjects during the short rest pauses in IH. Therefore, a plausible explanation was that the prolongation oft lim in IH may have been related to differences at a sensory level. It was concluded that short rest periods, if introduced in exercise with long cycle-times, could give an immediate sense of relief, postponing the subjective threshold of fatigue. Thus the results of this study provided experimental support for the hypothesis that the introduction of micropauses may create an increased risk of musculoskeletal disorders.

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

  • Armstrong TJ, Radwin RG, Hansen DJ, Kennedy KW (1984) Repetitive trauma disorders: job evaluation and design. Hum Factors 28:325–336

    Google Scholar 

  • Bergquist Y, Hed K, Karlberg B (1988) An improved flow injection method for determination of lactate during exercise studies. Int J Sports Med 9:73–76

    PubMed  Google Scholar 

  • Bigland-Ritchie B, Woods JJ (1984) Changes in muscle contractile properties and neural control during human muscular fatigue. Muscle Nerve 7:691–699

    PubMed  Google Scholar 

  • Bigland-Ritchie B, Furbush F, Woods JJ (1986) Fatigue of intermittent submaximal voluntary contractions: central and peripheral factors. J Appl Physiol 61:421–429

    PubMed  Google Scholar 

  • Björksten M, Jonsson B (1977) Endurance limit of force in longterm intermittent static contractions. Scand J Work Environ Health 3:23–27

    PubMed  Google Scholar 

  • Borg G (1982) Psychophysical bases of perceived exertion. Med Sci Sports Exerc 14:377–381

    PubMed  Google Scholar 

  • Byström SEG, Kilbom Å (1990) Physiological response in the forearm during and after intermittent isometric handgrip. Eur J Appl Physiol 60:457–466

    Google Scholar 

  • Byström SEG, Kilbom Å (1991) Electrical stimulation of the human forearm extensors as an indicator of handgrip fatigue and recovery. Eur J Appl Physiol 62:363–368

    Google Scholar 

  • Byström SEG, Sjøgaard G (1991) Potassium homeostasis during and following exhaustive submaximal isometric handgrip contractions. Acta Physiol Scand 142:59–66

    PubMed  Google Scholar 

  • Chatterjee DS (1987) Repetition strain injury — a recent review. J Soc Occup Med 37:100–105

    PubMed  Google Scholar 

  • Checkoway H, Pearce NE, Crawford-Brown DJ (1989) Research methods in occupational epidemiology. Oxford University Press, Oxford

    Google Scholar 

  • Clamann HP (1978) Intracellular activities of sodium and potassium. Am J Physiol 234:F261-F261

    PubMed  Google Scholar 

  • Coles DR, Cooper KE, Mottram RF, Occleshaw JV (1958) The source of blood samples withdrawn from deep forearm veins via catheters passed upstream from the median cubital vein. J Physiol 142:323–328

    PubMed  Google Scholar 

  • Hägg G (1981) Electromyographic fatigue analysis based on the number of zero crossings. Pflügers Arch 391:78–80

    Google Scholar 

  • Hagberg M (1981) Muscular endurance and surface electromyogram in isomeric and dynamic exercise. J Appl Physiol Respir Environ Exerc Physiol 51:1–7

    Google Scholar 

  • Harding OJ, Trap-Jensen J (1983) Haemodynamic and metabolic effects of alfa-adrenoceptor blockade with phentolamine at rest and during forearm exercise. Clin Sci 65:247–253

    PubMed  Google Scholar 

  • Kahn JF, Monod H (1984) A study of fatigue during repetitive static work performed in two different segmental positions. Eur J Appl Physiol 53:169–174

    Google Scholar 

  • Kilbom Å, Persson J (1981) Circulatory response to static muscle contractions in three different muscle groups. Clin Physiol 1:215–225

    Google Scholar 

  • Kroon GW, Naeije M (1988) Recovery following exhaustive dynamic exercise in the human biceps muscle. Eur J Appl Physiol 58:228–232

    Google Scholar 

  • Lind AR, Taylor SH, Humphreys PW, Kennelly BM, Donald KW (1964) The circulatory effects of sustained voluntary muscle contraction. Clin Sci 27:229–244

    PubMed  Google Scholar 

  • Mathiassen SE, Winkel J (1991) Quantifying variation in physical load, using exposure-vs-time data. Ergonomics (in press)

  • Milerad E, Kilbom Å (1985) Physiological and electromyographic response to repetitive handgrip exercise. Clin Physiol 5 [Suppl 4]:134

    Google Scholar 

  • Müller EA (1935) Der Einfluss von Arbeitsgrösse, Pausenlänge und Pausenverteilung auf die Ermüdung bei statischer Haltearbeit. Arbeitsphysiologie 8:435–445

    Google Scholar 

  • Mundale M (1970) The relationship of intermittent isometric exercise to fatigue of hand grip. Arch Phys Med Rehabil 51:532–539

    PubMed  Google Scholar 

  • Reddy HK, Weber K, Janicki I, McElroy P (1988) Hemodynamic, ventilatory and metabolic effects of light isometric exercise in patients with chronic heart failure. J Am Coll Cardiol 12:353–358

    PubMed  Google Scholar 

  • Rohmert W (1960) Ermittlung von Erholungspausen für statische Arbeit des Menschen. Int Z Angew Physiol Einschl Arbeitsphysiol 18:123–164

    Google Scholar 

  • Roto P, Kivi P (1984) Prevalence of epicondylitis and tenosynovitis among meatcutters. Scand J Environ Health 10:203–205

    Google Scholar 

  • Saltin B, Sjøgaard G, Gaffney FA, Rowell LB (1981) Potassium, lactate and water fluxes in human quadriceps muscle during static contractions. Circ Res 48 [Suppl]:I–18-I–24

    Google Scholar 

  • Siegel S, Castellan NJ (1988) Nonparametric statistics for the behavioral sciences. McGraw-Hill, New York

    Google Scholar 

  • Sjøgaard G, Kiens B, Jørgensen K, Saltin B (1986) Intramuscular pressure, EMG and blood flow during low-level prolonged static contraction in man. Acta Physiol Scand 128:475–484

    PubMed  Google Scholar 

  • Sjøgaard G, Savard G, Juel C (1988) Muscle BF during isometric activity and its relation to muscle fatigue. Eur J Appl Physiol 57:327–335

    Google Scholar 

  • Skinner SL, Whelan RF (1962) The circulation in forearm skin and muscle during adrenaline infusions. Aust J Exp Biol 40:163–172

    Google Scholar 

  • Tichauer ER (1973) Ergonomic aspects of biomechanics. In: NIOSH (ed) The industrial environment — its evaluation and control. US Government Printing Office, Washington DC

    Google Scholar 

  • Whitney RJ (1953) The measurement of volume changes in human limbs. J Physiol (Lond) 121:1–27

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Byström, S.E.G., Mathiassen, S.E. & Fransson-Hall, C. Physiological effects of micropauses in isometric handgrip exercise. Europ. J. Appl. Physiol. 63, 405–411 (1991). https://doi.org/10.1007/BF00868070

Download citation

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF00868070

Key words

Navigation