Our aim was to study physiological response and acceptability of intermittent muscle contractions. Seven male subjects performed eight isometric handgrip exercises with altered contraction-relaxation periods but identical tension-time products. Local blood flow (BF), heart rate, blood pressure, electromyography, maximal voluntary handgrip contraction (MVC), and venous concentration of potassium and lactate of both forearms were followed during and up to 24 hours after the exercises. Wrist force response to electrical stimulation of a forearm muscle was used to investigate low-frequency fatigue (LFF). Ratings of perceived exertion were recorded during exercise. LFF was associated with a decreased functional capacity, which may be explained by a net potassium loss. Recovery BF was linearly related to mean contraction intensity of the experiments. Physiological criteria for acceptability of isometric exercise are suggested, based on the absence of fatigue during exercise and the return to baseline values within four hours of the recovery period. Based on these physiological criteria, intermittent hand grip contractions at (or higher than) a mean contraction intensity of 17% MVC and continuous handgrip contractions at (or higher than) 10% MVC were considered unacceptable.
Get full access to this article
View all access options for this article.
References
1.
Bellemare, F., and Grassino, A. (1982). Evaluation of human diaphragm fatigue. Journal of Applied Physiology, 53, 1196–1206.
2.
Bergquist, Y., Hed, K., and Karlberg, B. (1988). An improved flow injection method for determination of lactate during exercise studies. International Journal of Sports Medicine, 9, 73–76.
3.
Bigland-Ritchie, B., Furbush, F., and Woods, J. J. (1986). Fatigue of intermittent submaximal voluntary contractions: Central and peripheral factors. Journal of Applied Physiology, 61, 421–429.
4.
Björksten, M., and Jonsson, B. (1977). Endurance limit of force in long-term intermittent static contractions. Scandinavian Journal of Work, Environment & Health, 3, 23–27.
5.
Borg, G. (1982). Psychophysical bases of perceived exertion. Medicine and Science in Sports and Exercise, 14, 377–381.
6.
Byström, S., and Kilborn, Å. (1990). Physiological response in the forearm during and after isometric intermittent handgrip. European Journal of Applied Physiology, 60, 457–466.
7.
Byström, S, and Kilborn, A. (1991). Electrical stimulation of human forearm extensor muscles as an indicator of handgrip fatigue and recovery. European Journal of Applied Physiology, 62, 363–368.
8.
Byström, S., Mathiassen, S. E., and Fransson-Hall, C. (1991). Physiological effects of micropauses in isometric handgrip exercise. European Journal of Applied Physiology, 63, 405–411.
9.
Byström, S., and Sjøgaard, G. (1991). Potassium homeostasis during and following exhaustive submaximal static handgrip contractions. Acta Physiology Scandinavia, 142, 59–66.
10.
Coles, D. R., Cooper, K. E., Mottram, R. F., and Occleshaw, J. V. (1958). The source of blood samples withdrawn from deep forearm veins via catheters passed upstream from the median cubital vein. Journal of Physiology, 142, 323–328.
11.
Dul, J., Douwes, M., and Smitt, P. (1990). A work-rest model for static postures. Biomechanics Seminar, 4, 117–124.
12.
Edwards, R. H. T. (1988). Hypotheses of peripheral and central mechanisms underlying occupational pain and injury. European Journal of Applied Physiology, 57, 275–278.
13.
Edwards, R. H. T., Hill, D. K., Jones, D. A., and Merton, P. A. (1977). Fatigue of long duration in human skeletal muscle after exercise. Journal of Physiology, 272, 769–778.
14.
Hagberg, M. (1981). Muscular endurance and surface electromyogram in isometric and dynamic exercise. Journal of Applied Physiology, 51(1), 1–7.
15.
Hagberg, M, and Kvarnström, S. (1984). Muscular endurance and electromyographic fatigue in myofascial shoulder pain. Archives of Physical Medicine and Rehabilitation, 65, 522–525.
16.
Hartling, O. J., Kelbaeck, H., Gjørup, T., Schibye, B., Klausen, K., and Trap-Jensen, J. (1989). Forearm oxygen uptake during maximal forearm dynamic exercise. European Journal of Applied Physiology, 58, 466–470.
17.
Hartling, O. J., and Trap-Jensen, J. (1983). Haemodynamic and metabolic effects of alfa-adrenoceptor blockade with phentolamine at rest and during forearm exercise. Clinical Science, 65, 247–253.
18.
Hicks, A., and McComas, A. J. (1989). Increased sodium pump activity following repetitive stimulation of rat soleus muscle. Journal of Physiology (Lond), 414, 337–349.
19.
Hägg, G. (1981). Electromyographic fatigue analysis based on the number of zero crossings. Pflügers Archive EuropeanJournal of Physiology, 91, 78–80.
20.
Hägg, G. (1991). Zero crossing rate as an index of electromyographic spectral alterations and its applications to ergonomics. Thesis, Chalmers University of Technology, Gothemburgh, Sweden.
21.
Jackson, M. J., Jones, D. A., and Edwards, R. H. T. (1984). Experimental skeletal muscle damage: The nature of the calcium-activated degenerative processes. European Journal of Clinical Investigations, 14, 369–374.
22.
Korthuis, R. J., and Granger, D. N. (1986). Ischemiareperfusion injury: Role of oxygen-derived free radicals. Physiology of oxygen radicals. Acta Physiology Scandinavia (suppl 548), 47–63.
23.
Kroon, G. W., and Naeije, M. (1988). Recovery following exhaustive dynamic exercise in the human biceps muscle. European Journal of Applied Physiology, 58, 225–232.
24.
Kurppa, K., Viikari-Juntura, J. E., Kuosma, E., Huuskonen, M., and Kivi, P. (1991). Incidence of tenosynovitis or peritendinitis and epicondylitis in a meatprocessing factory. Scandinavian Journal of Work, Environment & Health, 17(1), 32–37.
25.
Milerad, E., and Kilborn, Å. (1985). Physiological and electromyographic response to repetitive hand-grip exercise. Clinical Physiology, 5(Suppl 4), 134.
26.
Milner, N. P. (1985). Modelling fatigue and recovery in static postural exercise. Thesis, University of Nottingham, Nottingham, England.
27.
Mundale, M. (1970). The relationship of intermittent isometric exercise to fatigue of handgrip. Archives of Physical Medicine and Rehabilitation, 51, 532–539.
28.
Reddy, H. K., Weber, K., Janicki, J., and McElroy, P. (1988). Hemodynamic, ventilatory and metabolic effects of light isometric exercise in patients with chronic heart failure. Journal of the American College of Cardiology, 12, 353–358.
29.
Richardson, D. (1981). Blood flow response of human calf muscles to static contractions at various percentages of MVC. Journal of Applied Physiology, 51, 929–933.
30.
Rohmert, W. (1973). Problems in determining rest allowances: Part 1. Use of modern methods to evaluate stress and strain in static muscular work. Applied Ergonomics, 4(2), 91–95.
31.
Silverstein, B. A., Fine, L. J., and Armstrong, T. J. (1987). Occupational factors and carpal tunnel syndrome. American Journal of Industrial Medicine, 11, 343–358.
32.
Sjøgaard, G. (1988). Muscle energy metabolism and electrolyte shifts during low-level prolonged static contraction in man. Acta Physiology Scandinavia, 134, 181–187.
33.
Sjøgaard, G., Savard, G., and Juel, C. (1988). Muscle blood flow during isometric activity and its relation to muscle fatigue. European Journal of Applied Physiology, 57, 327–335.
34.
Vøllestad, N. K., and Sejersted, O. M. (1988). Biomedical correlates of fatigue. European Journal of Applied Physiology, 57, 336–347.
35.
Whitney, R. J. (1953). The measurement of volume changes in human limbs. Journal of Physiology (Lond), 121, 1–27.
36.
Williams, C. A., and Lind, A. R. (1979). Measurement of forearm blood flow by venous occlusion plethysmography: Influence of hand blood flow during sustained and intermittent isometric exercise. European Journal of Applied Physiology, 42, 141–149.
