Abstract
The purpose of this research was to perform isometric tests at two joint angles and examine their relationship to dynamic performance. In addition, electromyograph data were collected from the triceps brachii and pectoralis major muscles to compare underlying neural characteristics between the isometric tests and dynamic movement. A group of 24 healthy male subjects performed two isometric tests in a bench press position, at elbow angles of 90 and 120°. From these data, the maximal force and rate of force development were determined. In addition, each subject performed a seated medicine ball throw as a measure of dynamic upper body performance. Correlations showed that isometric measurements of force (r = 0.47–0.55) and rate of force development (r = 0.08–0.31) were poor predictors of dynamic performance. The angle of isometric assessment had little effect on the relationship between the tests and measurements of performance. The myo-electric data was processed in terms of the integrated electromyogram and the Fourier transformed frequency spectrum. These data demonstrated differences in the neural activation patterns of the musculature, between the isometric 90° test and the medicine ball throw. The poor relationship between isometric tests and medicine ball performance was consequently, at least partially, attributed to differing motor unit activation patterns between isometric and dynamic movement. The results of this research strongly suggest that isometric tests have limited value when assessing dynamic upper body performance.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bemben MG, Clasey JL, Massey BH (1990) The effect of the rate of muscle contraction on the force-time curve parameters of male and female subjects. Res. Q 61:96–99
Bigland Ritchie B, Johansson R, Lippold J, Wood JJ (1982) Changes of single motor unit firing rates during sustained maximal voluntary contractions. J Appl Physiol 328:27–28
Delagi G, Perotto B (1974) Anatomic guide for the electromyographer. Thomas, Springfield, Ill, pp 74–89
Fugslang-Frederiksen A. Reneger J (1988) The motor unit firing rate and the power spectrum of EMG in humans. Electroencephalogr Clin Neurophysiol 70:68–72
Gillespie J, Keenum S (1987) A validity and reliability analysis of the seated shotput as a test of power. J Hum Mov Stud 13:97–105
Hakkinen K (1993) Neuromuscular fatigue and recovery in male and female athletes during heavy resistence exercise. Int J Sports Med 14:53–59
Hakkinen K, Komi PV, Kauhanen H (1986) Electromyographic and force production characteristics of leg extensor muscles of elite weight lifters during isometric, concentric, and various stretchshortening cycle exercises. Int J Sports Med 7:144–151
Hakkinen K, Pakarinen A, Alen M, Kauhanen H, Komi PV (1987) Relationships between training volume, physical performance capacity, and serum hormone concentrations during prolonged training in elite weight lifters. Int J Sports Med 8:61–65
Jaric S, Ristanovic D, Corcoss DM (1989) The relationship between muscle kinetic parameters and kinematic variables in a complex movement. Eur J Appl Physiol 59:370–376
Lago P, Jones N (1977) Effect of motor unit firing time statistics on EMG spectra. Med Biol Eng Comput 15:648–655
Lindstrom L, Magnusson R. Petersen I (1970) Muscular fatigue and action potential changes studied with frequency analysis of EMG signals. Electromyogr Clin Neurophysiol 57:341–356
Mero A, Luhtanen P, Viitasalo JT, Komi PV (1981) Relationship between the maximal running velocity, muscle fiber characteristics, force production and force relaxation of sprinters. Scand J Sports Sci 3:16–22
Murphy AJ, Wilson GJ, Pryor JF (1994) The use of the iso-inertial force mass relationship in the prediction of dynamic human performance. Eur J Appl Physiol 69:250–257
Murphy AJ, Wilson GJ, Pryor JF, Newton RU (1995) Isometric assessment of muscular function: the effect of joint angle. J Appl. Biomech 11:205–215
Nakazawa K, Kawakami Y, Fukunaga T, Yano H, Miyashita M (1993) Differences in activation patterns in elbow flexor muscles during isometric, concentric and eccentric contractions. Eur J Appl Physiol 66:214–220
Okada M (1987) Effects of muscle length on surface EMG wave forms in isometric contractions. Eur J Appl Physiol 56:482–486
Otnes RK, Enochson L (1972) Digital time series analysis. Wiley and Sons, New York, pp 200–206.
Person R (1974) Rhythmic activity of a group of human motoneurons during voluntary contraction of muscle. Electroencephalogr Clin Neurophysiol 36:585–595
Pryor JF, Wilson GJ, Murphy AJ (1994) The effectiveness of eccentric, concentric and isometric rate of force development tests. J Hum Mov Stud 27:153–172
Ryushi T, Hakkinen K, Kauhanen H, Komi PV (1988) Muscle fibre characteristics, muscle cross-sectional area and force production in strength athletes, physically active males and females. Scand J Sports Sci 10:7–15
Sale DG (1991) Testing strength and power. In: MacDougall J, Wenger H, Green H (eds) Physiological testing of the high performance athlete, 2nd edn. Human Kineics, Champaign, Ill, pp 21–106.
Sale DG, Martin JE, Moroz DE (1992) Hypertrophy without increased isometric strength after weight training. Eur J Appl Physiol 64:51–55
Tidow G (1990) Aspects of strength training in athletics. New Stud Athletics 1:93–110
Viitasalo JT (1982) Effects of pretension on isometric force production. Int J Sports Med 3:149–152
Viitasalo JT, Aura O (1984) Seasonal fluctuation of force production in high jumpers. Can J Appl Sports Sci 9:209–213
Viitasalo JT, Saukkonen S, Komi PV (1980) Reproducibility of measurements of selected neuromuscular performance variables in man. Electromyogr Clin Neurophysiol 20:487–501
Viitasalo JT, Hakkinen K, Komi PV (1981) Isometric and dynamic force production and muscle fibre composition in man. J Hum Mov Stud 7:199–209
Wilson GJ, Wood GA, Elliot BC (1991) The performance augmentation achieved from the use of the stretch shorten cycle: the neuromuscular contribution. Aust J Sci Med Sport 23:96–100
Wilson GJ, Newton RU, Murphy AJ, Humphries B (1993) The optimal training load for the development of dynamic athletic performance. Med Sci Sports Exerc 25:1279–1286
Young WB, Bilby GE (1993) The effect of voluntary effort to influence speed of contraction on strength, muscular power and hypertrophy development. J Strength Cond Res 7:172–178
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Murphy, A.J., Wilson, G.J. Poor correlations between isometric tests and dynamic performance: relationship to muscle activation. Europ. J. Appl. Physiol. 73, 353–357 (1996). https://doi.org/10.1007/BF02425498
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02425498