Are Leg Electromyogram Profiles Symmetrical During Full Squat?

  • Henryk Król
  • Krzysztof Kmiecik
Conference paper
Part of the Advances in Intelligent Systems and Computing book series (AISC, volume 831)


In order to see how electromyogram (EMG) profiles change during the squat movement with increasing loads, we determined the degree of symmetry of selected homologous muscles. Seven healthy men (age range 20–42 years), recreationally performing strength exercises voluntarily participated in the research. The participants varied in height from 172 to 183 cm and in mass from 74 to 94 kg. The participants performed consecutive sets of a single repetition of full back squatting, each time with an increased load (70–100% 1RM). To record the parameters of participant and barbell movement, the Smart-E measuring system (six infrared cameras and a wireless module for measuring the bioelectric activity of muscles) were used. Electrical activity was recorded using surface electrodes for muscles on both sides of the body (homologous): tibialis anterior (TA), gastrocnemius medialis (Gmed), biceps femoris (BF), rectus femoris (RF), gluteus maximus (Gmax) and erector spinae (ES). The mean of averages of modules of amplitude differences (MAMAD) between individual pairs of normalized homologous muscles for squat movement was accepted as a measure of symmetry of homologous muscles. A statistically significant increase of symmetry of EMG profiles (MAMAD) with increasing loads was seen only for TA and ES muscles and only in two of the six of analyzed cases. Of particular interest was the statistically significant large MAMAD increase for BF and ES muscles and for the so called prime mover (Gmax) in the ascent phase of the squat compared to the descent phase.


Barbell squat Electromyography Muscle symmetry 


  1. 1.
    Arsenault, A.B., Winter, D.A., Marteniuk, R.G.: Bilateralism of EMG profiles in human locomotion. Am. J. Phys. Med. 65, 1–16 (1986)Google Scholar
  2. 2.
    Beachle, T.R., Earle, R.W., Wathen, D.: Resistance training. In: Baechle, T.R., Earle, R.W. (eds.) Essentials of Strength Training and Conditioning. Champaign, IL, pp. 381–412. Human Kinetics (2008)Google Scholar
  3. 3.
    Contreras, B., Vigotsky, A.D., Schoenfeld, B.J., Beardsley, C., Cronin, J.: A comparison of gluteus maximus, biceps femoris, and vastus lateralis EMG amplitude in the parallel, full, and front squat variations in resistance trained females. J. Appl. Biomech. 32(1), 16–22 (2016)CrossRefGoogle Scholar
  4. 4.
    Delavier, F.: Strength Training Anatomy. Human Kinetics, Champaign (2001)Google Scholar
  5. 5.
    Gullett, J.C., Tillman, M.D., Gutierrez, G.M., Chow, J.W.: A biomechanical comparison of back and front squats in healthy trained individuals. J. Strength Cond. Res. 23(1), 284–292 (2009)CrossRefGoogle Scholar
  6. 6.
    Hermens, J., Freriks, B., Merletti, R., Stegman, D., Blok, J., Rau, G., Disselhorst-Klug, C., Hägg, G., et al.: SENIAM 8: European Recommendations for Surface Electromyography. Roessingh Research and Development B.v., The Netherlands (1999)Google Scholar
  7. 7.
    Ingersoll, C.D., Grindstaff, T.L., Pietrosimone, B.G., Hart, J.M.: Neuromuscular consequences of anterior cruciate ligament injury. Clin. Sports Med. 27(3), 383–404 (2008)CrossRefGoogle Scholar
  8. 8.
    Kmiecik, K., Król, H., Sobota, G.: Are lower limb electromyogram profiles symmetrical during a barbell squat? J. Kinesiol. Exerc. Sci. 78(27), 65–74 (2017). (A case study). AntropomotorykaGoogle Scholar
  9. 9.
    Konrad, P.: ABC of EMG. A Practical Introduction to Kinesiological Electromyography. Version 1.0, Noraxon Inc., Scottsdale, Arizona, USA (2006)Google Scholar
  10. 10.
    Lyons, K., Perry, J., Gronley, J.K., Barnes, L., Antonelli, D.: Timing and relative intensity of hip extensor and abductor muscle action during level and stair ambulation: an EMG study. Phys. Ther. 10, 1597–1605 (1983)CrossRefGoogle Scholar
  11. 11.
    Murray, M.P., Mollinger Gardner, G.M., Sepic, S.B.: Kinematic and EMG patterns during slow, free, and fast walking. J. Orthop. Res. 2, 272–280 (1984)CrossRefGoogle Scholar
  12. 12.
    Nashner, L.M.: Balance adjustments of humans perturbed while walking. J. Neurophysiol. 44, 650–664 (1980)CrossRefGoogle Scholar
  13. 13.
    Ōunpuu, S., Winter, D.A.: Bilateral electromyographical analysis of the lower limbs during walking in normal adults. Electroencephalogr. Clin. Neurophysiol. 72, 429–438 (1989)CrossRefGoogle Scholar
  14. 14.
    Pierotti, S.E., Brand, R.A., Gabel, R.H., Pedersen, D.R., Clarke, W.R.: Are leg electromyogram profiles symmetrical? J. Orthop. Res. 9, 720–729 (1991)CrossRefGoogle Scholar
  15. 15.
    Robertson, D.G.E., Wilson, J.M.J., St. Pierre, T.A.: Lower extremity muscle functions during full squats. J. Appl. Biomech. 24, 333–339 (2008)CrossRefGoogle Scholar
  16. 16.
    Rudolph, K.S., Snyder, L.: Effect of dynamic stability on a step task in ACL deficient individuals. J. Electromyogr. Kinesiol. 14(5), 565–575 (2004)CrossRefGoogle Scholar
  17. 17.
    Trulsson, A., Garwicz, M., Ageberg, E.: Postural orientation in subjects with anterior cruciate ligament injury: development and first evaluation of a new observational test battery. Knee Surg. Sports Traumatol. Arthroscopy 18(6), 814–823 (2010)CrossRefGoogle Scholar
  18. 18.
    Trulsson, A., Miller, M., Hansson, G.-A., Gummesson, C., Garwicz, M.: Altered movement patterns and muscular activity during single and double leg squats in individuals with anterior cruciate ligament injury. BMC Musculoskelet. Disord. 6(1), 472–482 (2015)Google Scholar
  19. 19.
    Woltering, H., Güth, V., Abbink, F.: Electromyographic investigations of gait in cerebral palsied children. Electromyogr. Clin. Neurophysiol. 19, 519–533 (1979)Google Scholar
  20. 20.
    Yang, J.F., Winter, D.: Electromyographic amplitude normalization method: improving their sensitivity as diagnostic tools in gait analysis. Arch. Phys. Med. Rehabil. 65, 517–521 (1984)Google Scholar
  21. 21.
    Yang, J.F., Winter, D.: Surface EMG profiles during different walking cadences in humans. Electroencephalogr. Clin. Neurophysiol. 60(6), 485–491 (1985)CrossRefGoogle Scholar
  22. 22.
    Yavuz, H.U., Erdag, D.: Kinematic and electromyographic activity changes during back squat with submaximal and maximal loading. Appl. Bionics Biomech. 2017, 8 (2017)CrossRefGoogle Scholar

Copyright information

© Springer Nature Switzerland AG 2019

Authors and Affiliations

  1. 1.The Jerzy Kukuczka Academy of Physical Education in KatowiceKatowicePoland

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