Análise do exercício abdominal “crunch” realizado com cargas máximas e submáximas: Respostas eletromiográficas da musculatura abdominal

 

M.L. Moura, L.S. Tessutti, A.C. Moraes

Faculdade de Educação Física, Universidade de Campinas - UNICAMP, Brasil

Endereço para correspondência

 

RESUMO

O objetivo deste estudo foi verificar as respostas eletromiográficas dos músculos reto abdominal e oblíquo externo durante a realização do exercício abdominal “crunch”. Participaram no estudo 13 universitários de ambos os sexos (18 a 23 anos). O exercício abdominal crunch foi realizado até à exaustão, com sobrecargas de 20, 40, 60 e 80% da contração voluntária máxima (CVM). Os valores (mediana e semi-amplitude interquartílica) das três primeiras e três últimas repetições de cada carga foram expressos em root-mean-square (RMS). Observou-se um aumento nos valores de RMS das últimas repetições em relação às primeiras repetições na carga de 20%, nas duas primeiras na carga de 40% e na primeira repetição na carga de 80%. Não houve diferença em relação à carga de 60%. Os resultados demonstram que a utilização de sobrecargas no exercício abdominal pode ser uma alternativa de distinção da intensidade da aplicação do exercício de força, no que se diz respeito à variável intensidade da carga, o que pode tornar-se uma ferramenta prática e útil para ser aplicada em sujeitos que desejam aumentar o nível de força abdominal.

Palavras-chave: exercício abdominal "crunch", reto abdominal, obliquo externo, fadiga, sobrecarga, eletromiografia

 

Abdominal crunch exercise analysis performed with maximum and submaximum loads: An electromyographic study

ABSTRACT

The purpose of this study was to verify the electromyographic activity of the rectus abdominis and obliquus externus abdominis during abdominal crunch exercise performed with maximum and submaximum loads. Thirteen male and female university students participated in this investigation (18-23 years old). The subjects completed abdominal crunch exercise until exhaustion with 20, 40, 60 and 80% of the maximum load. The root-mean-square (RMS) from electromyography activity of the rectus abdominis and obliquus externus muscles from the first and last three repetitions from each workload performed was analyzed. RMS for the last repetitions increased in relation to the first repetitions for the 20% workload, first two repetitions on 40% workload and first repetition on the 80% workload. There was no difference for the 60% workload. Results showed that external load on abdominal crunch exercise might be an alternative to increase intensity while performing abdominal crunch exercise, which on its turn can be a practical tool for subjects that aim to increase abdominal strength level.

Keywords: abdominal crunch exercise, rectus abdominis muscle, obliquus externus muscle, fatigue, electromyography

 

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REFERÊNCIAS

Andersson E., Nilsson, J., Ma, Z., & Thorstensson, A. (1997). Abdominal and hip flexor muscle activation during various training exercises. European Journal of Applied Physiology Occupational Physiology, 75(2), 115-123.

Arjmand, N., Shirazi-Adl, A., & Parnianpour, M. (2008). Relative efficiency of abdominal muscles in spine stability. Computer Methods in Biomechanics and Biomedical Engineering, 11(3), 291-299.

Axler, C. T., & McGill, S. M. (1997). Low back loads over a variety of abdominal exercises: Searching for the safest abdominal challenge. Medicine & Science in Sports & Exercise, 29, 804-811.

Baechle, T. R., & Earle, R. W. (2000). Essentials of strength training and conditioning − National Strength and Conditioning Association. Champaign, IL: Human Kinetics.

Bankoff, A. D. P., & Furlani, J. (1986). Estudo eletromiográfico dos músculos: Reto abdominal e oblíquo externo. Revista Brasileira de Ciências Morfológicas, 2(2), 48-54.        [ Links ]

Beim, G. M., Giraldo, J. L., Pincivero, D. M., Borror, M. J., & Fu, F. H. (1997). Abdominal strengthening exercises: A comparative EMG study. Journal of Sport Rehabilitation, 6(1), 11-22.

Bird, M., Fletcher, K. M., & Koch, A. J. (2006). Electromyographic comparison of the Ab-Slide and crunch exercises. Journal of Strength and Conditioning Research, 20, 436-440.

Dankaerts, W., O’Sullivan, P. B., Burnett, A. F., Straker, L. M., & Danneels, L. A. (2004). Reliability of EMG measurements for trunk muscles during maximal and sub-maximal voluntary isometric contractions in healthy controls and CLBP patients. Journal of Electromyography and Kinesiology, 14(3), 333-342.

De Luca, C. J. (1997). The use of surface electromyography in biomechanics. Journal of Applied Biomechanics, 13, 135-163.

Demont, R. G., Lephart, S. M., Giraldo, J. L., Giannantonio, F. P., Yuktanandana, P., & Fu, F. H. (1999). Comparison of two abdominal training devices with an abdominal crunch using strength and EMG measurements. The Journal of Sports Medicine and Physical Fitness, 39(3), 253-258.

Escamilla, R. F., Babb, E., Dewitt, R., Jew, P., Kelleher, P., Burnham, T., et al. (2006). Electromyographic analysis of traditional and nontraditional abdominal exercises: Implications for rehabilitation and training. Physical Therapy, 86(5), 656-671.

Flint, M. M., & Gudgell, J. (1965). Electro-myographic study of abdominal muscular activity during exercise. Research Quarterly, 36(1), 29-37.

Floyd, W. F., & Silver, P. H. (1950). Electromyographic study of patterns of activity of the anterior abdominal wall muscles in man. Journal of Anatomy, 84(2), 132-145.

Fry, A. C. (2004). The role of resistance exercise intensity on muscle fibre adaptations. Sports Medicine, 34(10), 663-679.

Gibson, A., & Noakes, T. D. (2004). Evidence for complex system integration and dynamic neural regulation of skeletal muscle recruitment during exercise in humans. British Journal of Sports Medicine, 38(6), 797-806.

Guimaraes, A. C., Vaz, M. A., Campos, M. I., & Marantes, R. (1991). The contribution of the rectus abdominis and rectus femoris in twelve selected abdominal exercises: An electromyographic study. The Journal of Sports Medicine and Physical Fitness, 31(2), 222-230.

Hildenbrand, K., & Noble, L. (2004). Abdominal muscle activity while performing trunk-flexion exercises using the AbRoller, AbSlide, FitBall, and conventionally performed trunk curls. Journal of Athletic Training, 39(1), 37-43.

Hoeger, W. W. K., Hopkins, D. R., Barette, S. L., & Hale, D. F. (1990). Relationship between repetitions and selected percentages of one repetition maximum: A comparison between untrained and trained males and females. Journal of Applied Sport Science Research, 4(2), 47-54.

International Society of Electrophysiology and Kinesiology − ISEK (1999). Standards for reporting EMG data. Journal of Electromyography and Kinesiology, 9(1), iii-iv.

Jackson, C. P., & Brown, M. D. (1983). Analysis of current approaches and a practical guide to prescription of exercise. Clinical Orthopaedics and Related Research, 179, 46-54.

Konrad, P. (2005). The ABC of EMG: A practical introduction to kinesiological electromyography. Boston: Noraxicon Inc.

Lehman, G. J., & McGill, S. M. (1999). The importance of normalization in the interpretation of surface electromyography: A proof of principle. Journal of Manipulative and Physiological Therapeutics, 22(7), 444-446.

Matuszak, M. E., Fry, A. C., Weiss, L. W., Ireland, T. R., & McKnight, M. M. (2003). Effect of rest interval length on repeated 1 repetition maximum back squats. Journal of Strength and Conditioning Research, 17, 634-637.

Moraes, A. C., Bankoff, A. D., Almeida, T. L., Simões, E. C., Rodrigues, C. E., & Okano, A. H. (2003). Using weights in abdominal exercises: Electromyography response of the Rectus Abdominis and Rectus Femoris muscles. Electromyography and Clinical Neurophysiology, 43(8), 487-496.

Moraes, A. C., Bankoff, A. D., Pellegrinotti, L. L., Moreira, Z. W., & Galdi, E. H. (1995). Electromyography analysis of the rectus abdominis and external oblique muscles of children 8 to 10 years old. Electromyography and Clinical Neurophysiology, 35(7), 425-430.

Moraes, A. C., Fontes, E. B., Gonçalves, E. M., Okano, A. H., Altimari, L. R., Batista, A. R., et al. (2009). Electromyography response of the abdominal muscles during curl-up exercises with different loads. Gazzetta Medica Italiana: Archivio per le Scienze Mediche, 168(5), 289-296.

Moraes, A. C., Pinto, R. S., Valamatos, M. J., Valamatos, M. J., Pezarat-Correia, P. L., Okano, A. H., et al. (2009). EMG activation of abdominal muscles in the crunch exercise performed with different external loads. Physical Therapy in Sport, 10, 57-62.

Ng, J. K., Kippers, V., Parniapour, M., & Richardson, C. A. (2002). EMG activity normalization for trunk muscles in subjects with and without back pain. Medicine & Science in Sports & Exercise, 34(7), 1082-1086.

Sheffield, F. J., & Major, M. C. (1962). Electromyographic study of the abdominal muscles in walking and other movements. American Journal of Physical Medicine, 41, 142-147.

Silva, E. M., Brentano, M. A., Cadore, E. L., Almeida, A. P., & Kruel, L. F. (2008). Analysis of muscle activation during different leg press exercises at submaximum effort levels. Journal of Strength and Conditioning Research, 22(4), 1059-1065.

Smidt, G., Herring, T., Amundsen, L., Rogers, M., Russell, A., & Lehmann, T. (1983). Assessment of abdominal and back extensor function: A quantitative approach and results for chronic low-back patients. Spine, 8(2), 211-219.

Stanton, R., Reaburn, P. R., & Humphries, B. (2004). The effect of short-term Swiss ball training on core stability and running economy. Journal of Strength and Conditioning Research, 18(3), 522-528.

Sternlicht, E., Rugg, S. G., Bernstein, M. D., & Armstrong, S. D. (2005). Electromyographic analysis and comparison of selected abdominal training devices with a traditional crunch. Journal of Strength and Conditioning Research, 19(1), 157-162.

Sternlicht, E., Rugg, S., Fujji, L. L., Tomomitsu, K. F., & Seki, M. M. (2007). Electromyographic comparison of a stability ball crunch with a traditional crunch. Journal of Strength Conditioning Research, 21(2), 506-509.

Stevens, V. K, Parlevliet, T. G., Coorevits, P. L., Mahieu, N. N., Bouche, K. G., Vanderstraeten, G. G., et al. (2008). The effect of increasing resistance on trunk muscle activity during extension and flexion exercises on training devices. Journal of Electromyography and Kinesiology, 18, 434-445.

Taylor, J. L., & Gandevia, S. C. (2008). A comparison of central aspects of fatigue in submaximal and maximal voluntary contractions. Journal of Applied Physiology, 104(2), 542-550.

Walters, C. E., & Partridge, M. J. (1957). Electromyographic study of the differential action of the abdominal muscles during exercise. American Journal of Physical Medicine, 36(5), 259-268.

Warden, S. J., Wajswelner, H., & Bennell, K. L. (1999). Comparison of Abshaper and conventionally performed abdominal exercises using surface electromyography. Medicine & Science in Sports & Exercise, 31(11), 1656-1664.

Zatsiorsky, V., & Seluyanov, V. (1983). The mass and inertia characteristics of the main segments of the human body. In H. Matsui & K. Kobayashi (Eds.), Biomechanics VIII-B (pp. 1152-1159). Champaign, IL: Human Kinetics.

 

Financiamento.Processo FAPESP 04-12589-0

 

Endereço para correspondência: Antonio Carlos de Moraes, Faculdade de Educação Física – UNICAMP, Rua Erico Veríssimo, 701 – Caixa Postal 6134, CEP 13083-851 Campinas – SP, Brasil.

E-mail: acmoraes@fef.unicamp.br

 

Submetido: 21.02.2010      Aceite: 01.07.2010