THE ROLE OF COUNTERMOVEMENT IN THE MANIFESTATION OF EXPLOSIVE LEG STRENGTH IN VERTICAL JUMPS
Abstract
Abstract. In order to explain the role of countermovement in the manifestation of explosive strength in vertical jumps performed with and without countermovement, the difference between the components of explosive strength in those jumps was analyzed on a sample of 44 elite Serbian cadet age volleyball players. The sample of tests consisted of eight components of explosive strength manifested in vertical jumps: jump height, maximal vertical speed, duration of the concentric jump phase, maximal force, maximal relative force, the ratio between maximal force and duration of the concentric jump phase, maximal power during the concentric jump phase and the average power during the concentric jump phase. The results have shown that all the components of explosive strength are significantly greater in the case of the countermovement jump in comparison to the squat jump, except for maximal power during the concentric jump phase. The greatest differences at the numeric level are noted in terms of the force/time ratio (3415 N/s or 59.9 %), then in average power in the concentric jump phase (611 W or 38.3 %), as well as in the duration of the concentric jump phase (0.076 s or 26.7 %) and jump height (7.9 cm or 23.5 %). Nonetheless, differences are also noted in maximal relative force (0.33 N or 14.1 %) and in maximal force (215 N or 13.4 %). The least significant differences are noted in maximal vertical speed (0.09 m/s or 3.5 %). In the case of maximal power during the concentric jump phase (Pmax), no significant differences were noted. The ensuing differences are ascribed to the role of the countermovement, which produces the changes in muscle activation, and initiates the stretch-shortening cycle of the muscle, as well as the occurrence of the 'elastic potentiation' of the muscles in the case of the countermovement jump, and thus increased muscle work.
Key words: countermovement, explosive leg strength, vertical jump, volleyball players.
Full Text:
PDFReferences
Bobbert, M. F., & van Ingen Schenau, G.J. (1990). Isokinetic plantar flexion: Experimental results and model calculations. Journal of Biomechanics, 23, 105-111.
Bobbert, M. F., Gerritsen, K. G., Litjens, M. C., & Van Soest, A. J. (1996). Why is countermovement jump height greater than squat jump height?. Medicine and science in sports and exercise, 28, 1402-1412.
Bosco Ergojump System (Byomedic, S.C.P., Barcelona, Spain). Found and downloaded 05.09.2015. from the World Wide Web: http://www.topendsports.com/testing/bosco-ergo-jump.htm.
Chapman, A. E., Caldwell, G. E., & Selbie, W. S. (1985). Mechanical output following muscle stretch in forearm supination against inertial loads. Journal of Applied Physiology, 59(1), 78-86.
Cole, T. J., Bellizzi, M. C., Flegal, K. M., & Dietz, W. H. (2000). Establishing a standard definition for child overweight and obesity worldwide: international survey. Bmj, 320(7244), 1240.
Dietz, V., Schmidtbleicher, D., & Noth, J. (1979). Neuronal mechanisms of human locomotion. Journal of Neurophysiology, 42(5), 1212-1222.
Ettema, G. J., Huijing, P. A., van Ingen Schenau, G. J., & De Haan, A. (1990). Effects of prestretch at the onset of stimulation on mechanical work output of rat medial gastrocnemius muscle-tendon complex. Journal of Experimental Biology, 152(1), 333-351.
Finni, T., Komi, P. V., & Lukkariniemi, J. (1998). Achilles tendon loading during walking: application of a novel optic fiber technique. European Journal of Applied Physiology and Occupational Physiology, 77(3), 289-291.
Finni, T., Komi, P. V., & Lepola, V. (2000). In vivo human triceps surae and quadriceps femoris muscle function in a squat jump and counter movement jump. European Journal of Applied Physiology, 83(4-5), 416-426.
Finni, T., Ikegaw, S., Lepola, V., & Komi, P. (2001). In vivo behavior of vastus lateralis muscle during dynamic performances. European Journal of Sport Science, 1(1), 1-13.
Gollhofer, A., Strojnik, V., Rapp, W., & Schweizer, L. (1992). Behaviour of triceps surae muscle-tendon complex in different jump conditions. European Journal of Applied Physiology and Occupational physiology, 64(4), 283-291.
Häkkinen, K., Komi, P. V., & Kauhanen, H. (1986). Electromyographic and force production characteristics of leg extensor muscles of elite weight lifters during isometric, concentric, and various stretch-shortening cycle exercises. International Journal of Sports Medicine, 7(3), 144-151.
Häkkinen, K. (1993). Changes in physical fitness profile in female basketball players during the competitive season including explosive type strength training. The Journal of sports medicine and physical fitness, 33(1), 19-26.
Ham, D. J., Knez, W. L., & Young, W. B. (2007). A determinictic model od the vertical jump: Implications for training. The Journal of Strength & Conditioning Research, 21(3), 967-972.
Henry, H. T., Ellerby, D. J., & Marsh, R. L. (2005). Performance of guinea fowl Numida meleagris during jumping requires storage and release of elastic energy. Journal of Experimental Biology, 208(17), 3293-3302.
Herodek, K. (2006). General anthropomotorics [In Serbian]. Nis: Self authorship edition.
Komi, P. (1979). Neuromuscular performance: Factors influencing force and speed production. Scandinavian Journal of Sports Science, 1, 2-15.
Komi, P. (1992). Stretch-shortening cycle. In: Komi PV. (Ed.), Strength and power in sport. Blackwell Scientific Publ, Oxford, 169-179.
Komi, P., & Gollhofer, A. (1997). Stretch reflex can have an important role in force enhancement during SSC- exercise. Journal of Applied Biomechanics, 1, 3451–3460.
Kraemer, W. J., & Newton, R. U. (1994). Training for improved vertical jump. Sports Science Exchange, 7(6), 1-12.
Markovic, S., Mirkov, D. M., Knezevic, O. M., & Jaric, S. (2013). Jump training with different loads: effects on jumping performance and power output. European journal of applied physiology, 113(10), 2511-2521.
McBride, J. M., McCaulley, G. O., & Cormie, P. (2008). Influence of preactivity and eccentric muscle activity on concentric performance during vertical jumping. The Journal of Strength & Conditioning Research, 22(3), 750-757.
Jones, G. M., & Watt, D. G. D. (1971). Observations on the control of stepping and hopping movements in man. The Journal of Physiology, 219(3), 709-727.
Schmidtbleicher, D. (1992). Training for power events. In: Komi PV, (Ed.). Strength and power in sport (pp. 169-179). Oxford: Blackwell.
Semmler, J. G., Steege, J. W., Kornatz, K. W., & Enoka, R. M. (2000). Motor-unit synchronization is not responsible for larger motor-unit forces in old adults. Journal of Neurophysiology, 84(1), 358-366.
van Ingen Schenau, G. J., Bobbert, M. F., & de Haan, A. (1997). Does elastic energy enhance work and efficiency in the stretch-shortening cycle?. JAB, 13(4).
van Soest, A. J., & Bobbert, M. F. (1993). The contribution of muscle properties in the control of explosive movements. Biological cybernetics, 69(3), 195-204.
Walshe, A. D., Wilson, G. J., & Ettema, G. J. (1998). Stretch-shorten cycle compared with isometric preload: contributions to enhanced muscular performance. Journal of Applied Physiology, 84(1), 97-106.
Weiner, J. S., & Lourie, J. A. (1981). Practical Human Biology. New York: Academic Press.
Zajac, F. E., & Gordon, M. E. (1989). Determining muscle's force and action in multi-articular movement.
Exercise and sport sciences reviews, 17(1), 187-230.
Zatsiorsky, V.M. (1995). Science and practice of srength training. Champaign, IL: Human kinetics.
Refbacks
- There are currently no refbacks.
ISSN 1451-740X (Print)
ISSN 2406-0496 (Online)