نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری رفتار ‌حرکتی، دانشگاه تهران

2 دانشیار رفتار‌ حرکتی و روان‌شناسی ورزشی، دانشگاه تهران

3 استادیار بیومکانیک ورزشی، پژوهشگاه علوم ورزشی

چکیده

در مطالعات متفاوتی برتری کانون توجه بیرونی نسبت به کانون توجه درونی با استفاده از معیارهای نسبتاً ساده توصیف شده است.این پژوهش با هدف آزمون فرضیة عمل محدود­شدة کانون توجه از­طریق بررسی مکانیسم­های زیربنایی نوروفیزیولوژیک عضلات اندام تحتانی در پرش عمودی تحت‌تأثیر کانون­ توجه انجام شد. بدین‌منظور، 12 والیبالیست ماهر مرد (میانگین سنی92/1  ±24 سال، میانگین وزنی 8/7  ±5/73 کیلوگرم)که به‌صورت داوطلبانه در این پژوهش شرکت کرده بودند، حرکت پرش عمودی را روی صفحة نیروسنج در دو وضعیت کانون توجه بیرونی و درونی اجرا کردند. در طول پرش، سیگنال‌های الکترومایوگرافی سطحی عضلات اندام تحتانی با استفاده از دستگاه الکترومایوگرافی که با دستگاه صفحة نیروسنج از نظر زمانی همسان شده بود، ثبت شد. نتایج آزمون تی همبسته نشان داد که ارتفاع پرش در وضعیت کانون توجه بیرونی از وضعیت کانون توجه درونی­ بیشتر بود. همچنین، نتایج آزمون تحلیل واریانس مرکب نشان داد که تفاوت معناداری در زمان شروع و پایان فعالیت عضلانی در دو وضعیت کانون توجه بیرونی و درونی وجود نداشت (زمان شروع: (0.85 = P)، زمان پایان: (0.08 =P ). بین فعالیت الکتریکی عضلات در فاز درونگرای پرش عمودی در دو وضعیت کانون توجه بیرونی و درونی تفاوت معنادار وجود داشت (0.005 = P)، اما در فاز برونگرا تفاوت معنا­دار مشاهده نشد (0.069 =P ). این نتایج حاکی از این است که هماهنگی برون‌عضلانی تحت‌تأثیر نوع کانون توجه قرار نمی­گیرد، اما هماهنگی درون‌عضلانی تحت‌تأثیر کانون توجه بیرونی افزایش می­یابد و کانون توجه بیرونی موجب توسعة خودکاری بیشتر در کنترل حرکات می­شود که این موضوع با فرضیة عمل محدودشده هم‌راستاست.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

The Effect of External and Internal Focus of Attention on Electromyography of the Lower Extremity Muscles in Different Phases of Vertical Jump

نویسندگان [English]

  • Fardin Qeysari 1
  • Mehdi Shahbazi 2
  • Shahzad Tahmasebi Boroujeni 2
  • Ali Sharifnejad 3

1 PhD Student in Motor Behavior, University of Teheran

2 Associate Professor of Motor Behavior and Sport Psychology, University of Teheran

3 Assistant Professor of Sport Biomechanics, Sport Science Research Institute

چکیده [English]

Different studies have shown the advantage of the external focus of attention using relatively simple variables. The aim of this study was to investigate the constrained action hypothesis by underlying neurophysiological mechanisms tests of the lower extremity muscle in vertical jump under the impression of Focus of Attention Types. For this purpose, 12 male professional volleyball players (mean age: 24±1.92, mean weight: 73.5±8.7) performed a vertical jump on the force plate under two conditions in a counterbalanced order: external focus and internal focus. EMG activity of the lower extremity muscle was measured during jumps by using EMG device that coupled with force plate. Paired t-test results showed height of jump under the external focus was greater than that of the internal focus, while there were no significant differences in onset and offset times of the muscles activity between attentional focus conditions (onset times:(P=0.085), offset times:(P=0.08)). Also, the results show significant increases in EMG of the lower extremity with internal focus during concentric phase (P=0.005). However, there was no significant difference in EMG of these muscles between the internal and external focus in the eccentric phase (P=0.069). These results suggest that the intermuscular of coordination are not affected by the focus conditions but the intermuscular coordination is enhanced by the external focus of attention and the external focus of attention increase develop more automation of motor control.

کلیدواژه‌ها [English]

  • Vertical Jump
  • Timing Muscles
  • EMG Activity
  • Focus of Attention
  1. Wulf, G., McNevin, N., & Shea, C. H. The automaticity of complex motor skill learning as a function of attentional focus. The Quarterly Journal of Experimental Psychology Section A, 2001;54(4), 1143-54.‏
  2. MCNEVIN, Nancy H.; SHEA, Charles H.; WULF, Gabriele. Increasing the distance of an external focus of attention enhances learning. Psychological research, 2003, 67.1: 22-9.‏
  3. Kearney, P. E. (2015). A distal focus of attention leads to superior performance on a golf putting task. International Journal of Sport and Exercise Psychology, 2015;13(4), 371-81.‏
  4. Tahmasebi F, Aslankhani M, Namazizadehi M. The effects of focusing attention and internal and external imagery on the acquisition and retention of dart throw skill. Research on Sport Sciences.2009;(25):99-126. (In Persian).
  5. Perreault Melanie E.; FRENCH, Karen E. External-focus feedback benefits free-throw learning in children. Research Quarterly for Exercise and Sport, 2015, 86.4: 422-7.‏
  6. Parvizi N, Shojaee M, Khalaji H, Daneshfar A. The effect of change direction of attention by using educational self-talking. Technique on the performance and learning o free basketball f throw at young student girls. Research in Sport Management and Motor Behavior. 2011:(1):41-51. (In Persian).
  7. Pahlevan Yali M, Shahbazi M, Aghapour Hasiri SM, Tahmasebi Boroujeni Sh, Shamsi Majelan A. The effect type of attentional focus and the frequency of feedback on explicit knowledge and the learning of basketball free throwing. Motor Behavior. 2019; 11(35):85-102. (In Persian).
  8. Salajeghe. A., Saberi Kakhki. A.R., Zareazade. M. (2014). The effect of attentional focus types as the self talk form on acquisition and retention of Basketball chest pass. Motor Behavior. 6(16):20-107. (Persian)
  9. H Hadler, R., Chiviacowsky, S., Wulf, G., & Schild, J. F. G. Children's learning of tennis skills is facilitated by external focus instructions. Motriz: Revista de Educação Física, 2014; 20(4), 418-22.‏
  10. Dana A, Eshgarf S, Bagheri S. The effect of manipulating attentional focus on performance of top-spine strike of skilled and novice table tennis players under high psychological pressure. journal of Motor Behavior. 2019;11(36):67-88. (In Persian).
  11. Abdollahipour R, Nieto MP, Psotta R, Wulf GJPoS, Exercise. External focus of attention and autonomy support have additive benefits for motor performance in children. 2017; 32:17-24.
  12. Alishah, E. R., Ates, O., & Ahmadi, M. The Effects of Attentional Focus on The Performance of Volleyball Jump Serve In Elite Players. European Journal of Physical Education and Sport Science.‏ 2017;11(36):78-988
  13. Ducharme, S. W., Wu, W. F., Lim, K., Porter, J. M., & Geraldo, F. Standing long jump performance with an external focus of attention is improved as a result of a more effective projection angle. The Journal of Strength & Conditioning Research, (2016); 30(1), 276-81.‏
  14. WULF, Gabriele, et al. Increased jump height and reduced EMG activity with an external focus. Human movement science, 2010, 29.3: 440-448.‏
  15. Kal E, Van der Kamp J, Houdijk H. External attentional focus enhances movement automatization: A comprehensive test of the constrained action hypothesis. Human Movement Science. 2013;32(4):527-39.
  16. Lohse KR, Jones M, Healy AF, Sherwood ED. The role of attention in motor control. J Exp Psychol Gen. 2014;143(2):930-48.
  17. Richer, Natalie, et al. The effects of attentional focus and cognitive tasks on postural sway may be the result of automaticity. Gait & Posture, 2017, 54: 45-9.‏
  18. Parhizkar Kohneh Oghaz J, Zarghami M, Ghotbi Varzaneh A, Ghorbani A. Differences related to age and attention in postural control. Journal of Development and Motor Learning. 2013;2(5):1-56. (In Persian).
  19. Baniasadi T, Namazi Zadeh M, Sheikh M. The effects of balance training and focus of attention on sway in postural and supra-postural tasks in the elderly population. Motor Behavior. 2019;11(36):89-104. (In Persian).
  20. Kal E, Van der Kamp J, Houdijk H. External attentional focus enhances movement automatization: A comprehensive test of the constrained action hypothesis. Human Movement Science. 2013;32(4):527-39.
  21. Vance J, Wulf G, Töllner T, McNevin N, Mercer J. EMG activity as a function of the performer's focus of attention. Journal of Motor Behavior. 2004;36(4):450-9.
  22. Marchant, David; GREIG, Matt; SCOTT, Catherine. Attentional focusing strategies influence muscle activity during isokinetic biceps curls. Athletic Insight: The Online Journal of Sport Psychology, 2008.‏
  23. Zachry T, Wulf G, Mercer JA, Bezodis N. Increased movement accuracy and reduced EMG activity in response to an external focus of attention. Medicine & Science in Sports & Exercise. 2005;37(5):396.
  24. Lohse KR, Sherwood DE, Healy AF. How changing the focus of attention affects performance, kinematics, and electromyography in dart throwing. Human Movement Science. 2010;29(4):542-55.
  25. Wulf G, Zachry T, Granados C, Dufek JS. Increases in jump-and-reach height through an external focus of attention. International Journal of Sports Science & Coaching. 2007;2(3):275-84.
  26. Wulf G, Dufek JS. Increased jump height with an external focus due to enhanced lower extremity joint kinetics. Journal of Motor Behavior. 2009;41(5):401-9.
  27. Shapiro DC, Zernicke RF, Gregor RJ, Diestel JD. Evidence for generalized motor programs using gait pattern analysis. Journal of Motor Behavior. 1981;13(1):33-47.
  28. WEINBERG, R. S., et al. Effect of association, dissociation and positive self-talk strategies on endurance performance. Canadian Journal of Applied Sport Sciences, 1984.;9(4):542-55.
  29. Kershner AL. The Effect of Internal vs. External focus of attention instructions on countermovement jump variables in NCAA division I baseball players. :University of Kansas; 2017.
  30. Linthorne NP. Analysis of standing vertical jumps using a force platform. American Journal of Physics. 2001;69(11):1198-204.
  31. Marchant DC, Greig M, Bullough J, Hitchen DJRQfE, Sport. Instructions to adopt an external focus enhance muscular endurance. 2011;82(3):466-73.
  32. Wulf G, Lewthwaite R. Conceptions of ability affect motor learning. Journal of Motor Behavior. 2009;41(5):461-7.
  33. Zachry, Tiffany L, "Effects of attentional focus on kinematics and muscle activation patterns as a function of expertise" (2005). UNLV Retrospective Theses & Dissertations. 1862. https://digitalscholarship.unlv.edu/rtds/1862
  34. Lohse KR, Sherwood DEJAp. Thinking about muscles: The neuromuscular effects of attentional focus on accuracy and fatigue. 2012;140(3):236-45.
  35. Conley MS, Stone MH, Nimmons M, Dudley GA. Resistance training and human cervical muscle recruitment plasticity. Journal of Applied Physiology. 1997;83(6):2105-11.
  36. Moritani T. Neural factors versus hypertrophy in the time course of muscle strength gain. American journal of Physical Medicine. 1979;58(3):115-30.