Skip to main content
Log in

Activation of agonist and antagonist muscles at different joint angles during maximal isometric efforts

  • Short Communication
  • Published:
European Journal of Applied Physiology Aims and scope Submit manuscript


The purpose of this study was to investigate the influence of different angles of the knee joint on the activation level of an agonist (quadriceps femoris muscle) and antagonist (biceps femoris muscle) from electromyographic activities and activation levels (twitch interpolation). Isometric torque measurements were performed on 23 healthy subjects at 10° intervals between 40° and 110° of knee joint flexion. Superimposed twitches at maximal voluntary contraction were applied and the voluntary activation estimated. To quantify the antagonist muscle activity, we normalized its integrated EMG (iEMG) value at each joint angle with respect to its iEMG value at the same angle when acting as an agonist at maximal effort. The activation levels at the knee-flexed position (80–110°) were higher than that at the knee-extended position (40–70°). The co-activation levels at 90, 100, and 110° were significantly higher than that the other knee angle. These results suggest that the activation level of an agonist (quadriceps femoris) muscle and the co-activation level of an antagonist (biceps femoris) muscle were higher in longer muscles than in shorter muscles. It was also concluded that the risk of knee injuries could be reduced by applying these mutual relationships between activation levels of agonist and antagonist muscles.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2


  • Babault N, Pousson M, Michaut A, Hoecke JV (2003) Effect of quadriceps femoris muscle length on neural activation during isometric and concentric contractions. J Appl Physiol 94:983–990

    PubMed  Google Scholar 

  • Baratta R, Solomonow M, Zhou BH, Letson D, Churnard R, D’Ambrosia R (1988) The role of antagonistic musculature in maintaining knee stability. Am J Sports Med 16:113–122

    CAS  PubMed  Google Scholar 

  • Becker R, Awiszus F (2001) Physiological alterations of maximal voluntary quadriceps activation by changes of knee joint angle. Muscle Nerve 24:667–672

    Article  CAS  PubMed  Google Scholar 

  • Bulow PM, Norregaard J, Danneskiold-Samsoe B, Mehlsen J (1993) Twitch interpolation technique in testing of maximal muscle strength: influence of potentiation, force level, stimulus intensity and preload. Eur J Appl Physiol 67:462–466

    CAS  Google Scholar 

  • Cresswell AG, Loscher WN, Thorstensson A (1995) Influence of gastrocnemius muscle length on triceps surae torque development and electromyographic activity in man. Exp Brain Res 105:283–290

    CAS  PubMed  Google Scholar 

  • Fukunaga T, Ichinose Y, Ito M, Kawakami Y, Fukashiro S (1997) Determination of fascicle length and pennation in a contracting human muscle in vivo. J Appl Physiol 82:354–358

    CAS  PubMed  Google Scholar 

  • Griffiths RI (1991) Shortening of muscle fibres during stretch of the active cat medial gastrocnemius muscle: the role of tendon compliance. J Physiol (Lond) 436:219–236

    Google Scholar 

  • Leedham JS, Dowling JJ (1995) Force-length, torque-angle and EMG-joint angle relationships of the human in vivo biceps brachii. Eur J Appl Physiol 70:421–426

    Google Scholar 

  • Solomonow M, Baratta R, Zhou BH, Shoji EEH, Bose W, Beck C, D’Ambrosia R (1987) The synergistic action of the anterior cruciate ligament and thigh muscles in maintaining joint stability. Am J Sports Med 15:207–213

    CAS  PubMed  Google Scholar 

  • Solomonow M, Baratta RV, D’Ambrosia R (1991) EMG-force relations of a single skeletal muscle acting across a joint: dependence of joint angle. J Electro Kinesiol 1:58–67

    Google Scholar 

  • Urbach D, Nebelung W, Weiler HT, Awiszus F (1999) Bilateral deficit of voluntary quadriceps muscle activation after unilateral ACL tear. Med Sci Sports Exerc 31:1691–1696

    Article  CAS  PubMed  Google Scholar 

  • Williams KR (1985) Biomechanics of running. Exerc Sports Sci Rev 13:389–441

    CAS  Google Scholar 

  • Winter DA. (1984) Kinematic and kinetic patterns in human gait: variability and compensating effects. Human Movement Sci 3:51–76

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Keitaro Kubo.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Kubo, K., Tsunoda, N., Kanehisa, H. et al. Activation of agonist and antagonist muscles at different joint angles during maximal isometric efforts. Eur J Appl Physiol 91, 349–352 (2004).

Download citation

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: