Effects of Trunk and Foot Positions on Electromyographic Activity and Co-contraction of Selected Lower Extremity Muscles During Leg-Press Resistance Training

Document Type : Original research papers

Authors

1 Department of Sport Biomechanics, Faculty of Sports Sciences, Bu Ali Sina University, Hamedan, Iran

2 Department of Sports Biomechanics, Faculty of Sports Sciences, Shahid Bahonar University of Kerman, Kerman, Iran.

Abstract

The purpose of this study was to determine the effects of trunk and foot positions on electromyographic activity and co-contraction of selected lower extremity muscles during leg-press resistance training. 12 male powerlifters performed leg-press movement while the backrest of leg-press machine was adjusted at 15°, 20°, 25°, and 30° angles relative to the horizon. The feet were placed in three different positions namely, top, middle, and bottom of the foot-plate. Electromyography activity of the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF), and semitendinosus (ST) muscles were recorded while performing leg-press task at different trunk-feet conditions. The muscle co-contraction at the knee joint was also calculated. When the feet were placed on top of the foot-plate, RF had greater activity at 15°, 20°, and 25° compared to 30° backrest position. VM showed greater activity at 20° and 25° compared to 30°. VL showed greater activity at 20° and 25° compared to 30°. It was also more active at 20° than at 25° of backrest position. The ST and BF were more active at 20° compared to other positions. There was a slight co-contraction ratio difference at 20°-tap degrees condition compared to other conditions. According to the results, it is recommended that, for the recruitment of more motor units when using the 45-degree leg-press machine, the backrest of the machine be adjusted at a 20° angle with the feet placed at the top of the foot-plate.

Keywords

Main Subjects

References

  1. Kouzaki M, Shinohara M, Masani K, Kanehisa H, Fukunaga T. Alternate muscle activity observed between knee extensor synergists during low-level sustained contractions. Journal of Applied Physiology. 2002;93(2):675-84.
  2. McCAW ST, MELRosE DR. Stance width and bar load effects on leg muscle activity during the parallel squat. Medicine and science in sports and exercise. 1999;31:428-36.
  3. Ninos JC, Irrgang JJ, Burdett R, Weiss JR. Electromyographic analysis of the squat performed in self-selected lower extremity neutral rotation and 30 of lower extremity turn-out from the self-selected neutral position. Journal of Orthopaedic & Sports Physical Therapy. 1997;25(5):307-15.
  4. Blackard DO, Jensen RL, Ebben WP. Use of EMG analysis in challenging kinetic chain terminology. Medicine and science in sports and exercise. 1999;31(3):443-8.
  5. Cogley RM, Archambault TA, Fibeger JF, Koverman MM. Comparison of muscle activation using various hand positions during the push-up exercise. Journal of strength and conditioning research. 2005;19(3):628-33.
  6. Flanagan S, Salem GJ, Wang MY, Sanker SE, Greendale GA. Squatting exercises in older adults: kinematic and kinetic comparisons. Medicine and science in sports and exercise. 2003;35(4):635.
  7. Matheson JW, Kernozek TW, Fater DC, Davies GJ. Electromyographic activity and applied load during seated quadriceps exercises. Medicine and science in sports and exercise. 2001;33(10):1713-25.
  8. Rabita G, Pérot C, Lensel-Corbeil G. Differential effect of knee extension isometric training on the different muscles of the quadriceps femoris in humans. European journal of applied physiology. 2000;83(6):531-8.
  9. Fleck, S.J. and W. Kraemer, Designing resistance training programs, 4E. 2014: Human Kinetics.
  10. Escamilla RF, Fleisig GS, Zheng NA, Lander JE, Barrentine SW, Andrews JR, Bergemann BW, Moorman III CT. Effects of technique variations on knee biomechanics during the squat and leg press. Medicine & Science in Sports & Exercise. 2001;33(9):1552-66.
  11. Bono CM. Low-back pain in athletes. JBJS. 2004;86(2):382-96.
  12. Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand. Exercise and fluid replacement. Medicine and science in sports and exercise. 2007;39(2):377-90.
  13. Haff GG. Roundtable discussion: Machines versus free weights. Strength & Conditioning Journal. 2000;22(6):18.
  14. Escamilla RF, Fleisig GS, Zheng N, Barrentine SW, Wilk KE, Andrews JR. Biomechanics of the knee during closed kinetic chain and open kinetic chain exercises. Medicine and science in sports and exercise. 1998;30(4):556-69.
  15. Herrington L, Al-Sherhi A. A controlled trial of weight-bearing versus non—weight-bearing exercises for patellofemoral pain. journal of orthopaedic & sports physical therapy. 2007;37(12):155-60.
  16. Kibler WB, Livingston B. Closed-chain rehabilitation for upper and lower extremities. JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 2001;9(6):412-21.

 

  1. Song CY, Lin YF, Wei TC, Lin DH, Yen TY, Jan MH. Surplus value of hip adduction in leg-press exercise in patients with patellofemoral pain syndrome: a randomized controlled trial. Physical therapy. 2009;89(5):409-18.
  2. Witvrouw E, Lysens R, Bellemans J, Peers K, Vanderstraeten G. Open versus closed kinetic chain exercises for patellofemoral pain. The American journal of sports medicine. 2000;28(5):687-94.
  3. Ohkoshi Y, Yasuda K, Kaneda K, Wada T, Yamanaka M. Biomechanical analysis of rehabilitation in the standing position. The American journal of sports medicine. 1991;19(6):605-11.
  4. Evans, N., Bodybuilding Anatomy. 2nd ed. 2015, Champaign, IL: Human Kinetics.
  5. Hamill, J. and K.M. Knutzen, Biomechanical basis of human movement. 2006: Lippincott Williams & Wilkins.
  6. Da Silva EM, Brentano MA, Cadore EL, De Almeida AP, Kruel LF. Analysis of muscle activation during different leg press exercises at submaximum effort levels. The Journal of Strength & Conditioning Research. 2008;22(4):1059-65.
  7. Edman KA, Elzinga G, Noble MI. Residual force enhancement after stretch of contracting frog single muscle fibers. The Journal of General Physiology. 1982;80(5):769-84.
  8. Hermens HJ, Freriks B, Merletti R, Stegeman D, Blok J, Rau G, Disselhorst-Klug C, Hägg G. European recommendations for surface electromyography. Roessingh research and development. 1999;8(2):13-54.
  9. Alkner BA, Tesch PA, Berg HE. Quadriceps EMG/force relationship in knee extension and leg press. Medicine and science in sports and exercise. 2000;32(2):459-63.
  10. Heiden TL, Lloyd DG, Ackland TR. Knee joint kinematics, kinetics and muscle co-contraction in knee osteoarthritis patient gait. Clinical biomechanics. 2009;24(10):833-41.
  11. Wilk KE, Escamilla RF, Fleisig GS, Barrentine SW, Andrews JR, Boyd ML. A comparison of tibiofemoral joint forces and electromyographic activit during open and closed kinetic chain exercises. The American journal of sports medicine. 1996;24(4):518-27.
  12. Neumann, D.A., Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 2010: Mosby/Elsevier.
  13. Edman KA, Elzinga G, Noble MI. Enhancement of mechanical performance by stretch during tetanic contractions of vertebrate skeletal muscle fibres. The Journal of physiology. 1978;281(1):139-55.
  14. Peterson DR, Rassier DE, Herzog W. Force enhancement in single skeletal muscle fibres on the ascending limb of the force–length relationship. Journal of Experimental Biology. 2004;207(16):2787-91.
  15. Freitas SR, Antunes A, Salmon P, Mendes B, Firmino T, Cruz-Montecinos C, Cerda M, Vaz JR. Does epimuscular myofascial force transmission occur between the human quadriceps muscles in vivo during passive stretching? Journal of biomechanics. 2019;83:91-6.
  16. Wirth K, Hartmann H, Sander A, Mickel C, Szilvas E, Keiner M. The impact of back squat and leg-press exercises on maximal strength and speed-strength parameters. The Journal of Strength & Conditioning Research. 2016;30(5):1205-12.

Files

History

  • Receive Date: 23 February 2021
  • Revise Date: 26 March 2021
  • Accept Date: 23 April 2021

Share

How to cite

Statistics