Document Type : Research Paper I Open Access I Released under CC BY 4.0 license


1 Sports Physiology Physical Activity and Health MSc Student, Department of Exercise Physiology, College of Physical Education and Sport Sciences of Tehran kharazmi University, Tehran, Iran

2 Associate Professor, Department of Exercise Physiology, College of Physical Education and Sport Sciences of Tehran kharazmi University, Tehran, Iran


The aim of this study was to examine the temporary effect of type and intensity of dynamic contractions on some electromyography and performance variables in professional track and field athletes. 9 subjects randomly performed one of the four protocols in 4 different days: usual warm-up (control group), warm-up and a set of four repetitions of negative half squatting (120% of 1RM), warm-up and a set of six repetitions of power-strength half squatting (80% of 1RM) and warm-up and a set of twelve repetitions of power-velocity half squatting (40% of 1RM). 7 minutes after each protocol, the subjects performed the maximum voluntary isometric contraction (MVIC) and vertical jump test. Simultaneously, EMG activity of the rectus femoris, vastus lateralis and biceps femoris muscles was registered in MVIC test and concentric phase of vertical jump. Then, maximum muscle activity and RMS/MVC ratio index was derived from EMG data. The results showed that vertical jump, the maximum muscle activity and RMS/MVC ratio significantly increased after negative and power-strength half squatting protocols compared with the control group (P≤0.05). Furthermore, negative half squatting protocol had more increase than power-strength half squatting (P≤0.05). So the special warm-up including half squatting with supra-maximal and close to the maximum intensities can improve vertical jump performance compared with the usual warm-up.


1. باپیران، محسن (2011). اثر حاد شدت و ویژگی پیش‌فعالی عضلانی بر حداکثر نیرو، سرعت پا و عملکرد پرش عمودی در مردان تمرین‌کرده، پایان‌نامۀ کارشناسی‌ارشد دانشگاه خوارزمی.
2. برایان، آر؛ مکینتاش، فلیپ؛ گاردینر، اف. (1390). ساختار و عملکرد عضلۀ اسکلتی، ترجمۀ رضا قراخانلو و همکاران، تهران: سمت، ص 452.
3. بومپا، تئودوراُ (1392). زمان‌بندی و طراحی تمرین قدرتی در ورزش، ترجمۀ حمید رجبی و همکاران، انتشارات پژوهشگاه تربیت بدنی، ص 268 و 269.
4. جعفرنژاد گرو، تیمور؛ فرهپور، نادر (1391). «مقایسۀ فعالیت الکترومایوگرافی عضلات در مهارت سنگ ورزش باستانی و پرس سینه»، مطالعات طب ورزش، ش11، ص 68 -57.
5. سلطانی ایچی، مهدی؛ معتمدی، پژمان؛  رجبی، حمید (1392). تأثیر حاد تمرین پلایومتریک همراه با تغییر ارتفاع فرود بر برخی از متغیرهای الکترومایوگرافی فرود- پرش پسران دانشگاهی، پایان‌نامۀ کارشناسی‌ارشد رشتۀ تربیت بدنی و علوم ورزشی گرایش فیزیولوژی ورزش.
6. عبدالملکی، عباس؛ معتمدی، پژمان؛ عنبریان، مهرداد؛ رجبی، حمید (1391). «اثر نوع و شدت انقباض‌های ارادی بر برخی متغیرهای الکتروفیزیولوژیایی پرش عمودی ورزشکاران دو ومیدانی»، فصلنامۀ المپیک، سال بیستم، ش 4، پیاپی 60، ص 17-7.
7. فرلی، پیتر و همکاران (1393). فیزیولوژی ورزشی پیشرفته، ترجمۀ شادمهر میرداد و همکاران، تهران: انتشارات پژوهشگاه تربیت بدنی و حتمی، ص 90- 86.
9. فیلیپ اف، گاردینر (1391). جنبه‌های عصبی عضلانی فعالیت بدنی، ترجمۀ رضا قراخانلو و دکتر احمد آزاد، انتشارات پژوهشگاه تربیت بدنی و علوم ورزشی، ص 146 و 288.
10. موگان، ران و همکاران (1392). بیوشیمی فعالیت‌های ورزشی، ترجمۀ عباسعلی گائینی و همکاران، تهران: سمت، ص 25.
11. همتی‌نژاد، مهرعلی؛ رحمانی‌نیا، فرهاد (1388). اندازه‌گیری و ارزشیابی در تربیت بدنی، تهران: حتمی، ص 135- 134.
12. Arabatzi, F., Patikas, D., Zafeiridis, A., Giavroudis, K., Kannas, T., Gourgoulis, V., et al.(2014)."The post-activation potentiation effect on squat jump performance: age and sex effect. Pediatric exercise science.,Vol.26,No.2,PP:187-94.
13. Batista, MA., Roschel, H., Barroso, R., Ugrinowitsch, C., Tricoli,V.(2011).'' Influence of strength training background on postactivation potentiation response''. Journal of strength and conditioning research / National Strength & Conditioning Association.Vol.25,NO.9,PP:2496-2502.
14. Bogdanis, GC., Tsoukos, A., Veligekas, P. solakis C.,Terzis,G.(2014)." Effects of muscle action type with equal impulse of conditioning activity on postactivation potentiation". Journal of strength and conditioning research / National Strength & Conditioning Association.Vol.28,No.9:PP2521-8.
15. Brzycki,M.(1993)."Strength testing: predicting a one-rep max from repetitions to fatigue" JOPERD.,Vol.64,PP:88-90.
16. Chiu, LZ., Fry., Schilling, BK., Johnson, EJ., Weiss, LW.(2004).''Neuromuscular fatigue and potentiation following two successive high intensity resistance exercise sessions''. Applied Physiology.Vol.92,No.4,PP:92-5.
17. Doan, BK., Newton, RU., Marsit, JL., Triplett-McBride, N., Koziris, LP., Fry and Kraemer, WJ.(2002).''Effects of increased eccentric loading on bench press 1RM''. Strength & Conditioning Research.Vol.16,No.1,PP:9-13.
18. French, DN., Kraemer, WJ., Cooke, CB.(2003)."Changes in Dynamic Exercise Performance Following a Sequence of Preconditionin Isometric Muscle Actions". Strength and Conditioning Research.Vol.17,No.4,PP:678-85.
19. Guellich, A. & Schmidtbleicher, D.(1996).“MVC-induced short-term potentiation of explosive force”. New Studies in Athletics, Vol.11,No.4,PP:67-81.
20. Hage, RE., Zakhem, E., Moussa, E. & Jacob, C.(2010). “Acute effects of heavy-load squats on consecutive vertical jump performance”. Science & Sports., Vol.22,No.3,PP:726-30.
 21. Hamada, T., Sale, DG, MacDougall, JD, Tarnopolsky, MA. (2000). "Postactivation potentiation, fiber type, and twitch contraction time in human knee extensor muscles". Journal of applied physiology.,Vol.88,No.6,PP:2131-7.
22. Hanson, ED., Leich, S. & Mynark, RG. (2007). “Acute effects of heavy- and light-load squat exercise on the kinetic measures of vertical jumping”. Journal of Strength and Conditioning Research, Vol.21,No.4,PP:1012-1017.
23. Hermens, HJ., Freriks, B., Merletti, R., Stegeman, D., Blok,  J., Rau, G., Disselhorst-Klug, C., Hagg, G.(1999). ''SENIAM 9 :European recommendations for surface electromyography''. ISBN:90-75452Roessingh Research and Development bv.PP:14-4.
24. Hoffman, JR., Ratamess, NA., Faigenbaum, AD., Mangine, GT. & Kang, J.(2007). “Effects of maximal squat exercise testing on vertical jump performance in American college football players”. Journal of Sports Science and Medicine,Vol. 6, PP:149-150.
25. Hilfiker, R., Hubner, K., Lorenz, T., Marti, B.(2007)."Effects of drop jumps added to the warm-up of elite sport athletes with a high capacity for explosive force development". Journal of strength and conditioning research / National Strength & Conditioning Association.Vol.21,No.2,PP:550-5.
26. Hsien-Te Peng a TWKb, Chen-Yi Song c.(2011).Quadricep and hamstring activation during drop jumps with changes in drop height. Physical Therapy in Sport.vol.12,pp:127-32.
27. Kimberly, J., TaiT,  Tran., Lee, E., Brown Jared, W., Coburn, Daniel, A., Judelson.(2011)." Effects of depth jump vs. box jump warm-ups on vertical jump in collegiate vs. club female volleyball players''.,Medicina Sportiva,Vol.15,No.3,PP:103-106.
28. Reardon, D., Hoffman, JR., Mangine, GT., Wells, AJ., Gonzalez, AM., Jajtner, AR.(2014).'' Do changes in muscle architecture affect post-activation potentiation?'' Journal of sports science & medicine. Vol.13,No.3,PP:483-92.
29. Rixon, PK., Lamont, HS. & Bemben, MG. (2007). “Influence of type of muscle contraction, gender, and lifting experience on Postactivation potentiation performance”. Journal of Strength and Conditioning Research, Vol.21,No.2,PP: 500-505.
30. Robbins, D. & Docherty, D. (2005). “Effect of loading on enhancement of power performance over three consecutive trials”. Journal of Strength and Conditioning Research, Vol.19,No.4,PP: 898-902.
31. Mccann, MR., Flanagan, SP.(2010)."The effects of exercise selection and rest interval on postactivation potentiation of vertical jump performance". Journal of strength and conditioning research / National Strength & Conditioning Association.,Vol.24,No.5,PP:1285-91.
32. Mola, JN., Bruce-Low , SS., Burnet, SJ.(2014)."Optimal recovery time for postactivation potentiation in professional soccer players". Journal of strength and conditioning research / National Strength & Conditioning Association.,Vol.28,No.6,PP:1529-37.
33. Laurent ,B., Seitz, G., Gregory, Haff.(2015) ''Factors Modulating Post-Activation Potentiation of Jump, Sprint, Throw, and Upper-Body Ballistic Performances: A Systematic Review with Meta-Analysis''. a systematic review with meta-analysis.journal of  Sports Medicine. Vol.46.2,pp: 231-240.
34. Peng, HT., Kernozek, TW., Song, CY.(2011)."Quadricep and hamstring activation during drop jumps with changes in drop height".journal of the Association of Chartered Physiotherapists in Sports Medicine,Vol.12,No.3,PP:127-32.
35. peter, k.(2005).'' the ABC of EMG.Noraxon INC''.USA.,version 1.0.
36. Smith, JC., Fry, A., Weiss, L.(2001).''The effects of highintensity exercise on a 10-second sprint cycle test Strength and Conditioning Research''.Vol.15,No.3,PP:344-8.
37. Sotiropoulos, K., Ilias, S., Marios. C., Karolina, B., Angelos, S., Helen, D. & Savvas, PT.(2010). “Effects of warm-up on vertical jump performance and muscle electrical activity using half-squats at low and moderate intensity”. Journal of Sports Science and Medicine ., Vol.9,PP: 326-331.
38. Weber, KR., Brown, LE., Coburn, JW. & Zinder, SM. (2008).“Acute effects of heavy load squats on consecutive squat jump performance”. Journal of Strength and Conditioning Research, Vol.22,No.3,PP:726-730.
39. Witmer, CA., Shala, ED. & Gavin, LM. (2010). “The acute effects of back squats on vertical jump performance in men and women”. Journal of Sports Science and Medicine, Vol. 9,PP: 206-213.