Download PDF
Int J Sports Med 2011; 32(10): 754-760
DOI: 10.1055/s-0031-1280777
Training & Testing
Georg Thieme Verlag KG Stuttgart · New York

Wrist Flexors are Steadier than Extensors

K. Salonikidis
1   Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece
,
I.G. Amiridis
1   Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece
,
N. Oxyzoglou
1   Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece
,
P. Giagazoglou
1   Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece
,
G. Akrivopoulou
1   Laboratory of Neuromechanics, Department of Physical Education and Sport Sciences at Serres, Aristotle University of Thessaloniki, Greece
› Author Affiliations
Further Information

Publication History



accepted after revision 14 May 2011

Publication Date:
12 September 2011 (online)

Also available at
    Permissions and Reprints

Abstract

To examine torque variability in 2 antagonistic muscles 20 individuals performed maximal and submaximal (5, 10, 20, 50 and 75% of Maximal Voluntary Contraction, MVC) isometric wrist flexions and extensions (5 s) at 5 different angles (230, 210, 180, 150 and 130°). The EMG activity of Flexor Carpi Ulnaris (FCU) and Extensor Digitorum (ED) was recorded and quantified as the integral of EMG. Participants showed higher maximal isometric torque (32.43±11.17 vs. 17.41±3.84 Nm) and lower coefficient of variability during wrist flexion compared to extension. The normalized agonist EMG increased across higher levels of torque for both wrist muscles. Interestingly, the coactivation of ED during wrist flexion was greater compared to the coactivation of FCU during wrist extension at 50 and 75% of MVC, regardless of wrist angle (f.e.: at 180° and 75% of MVC the normalised EMG of ED as antagonist was 14.84±5.18% vs. 9.33±6.94 of the FCU). It is concluded that a stronger isometric wrist flexion is more steadily produced, with greater coactivation compared to a weaker wrist extension, independently from muscle length and torque level. Even if the relative contribution of antagonists to the resultant torque is to be considered, altered activation patterns responsible for differences in force fluctuations could be suggested.

Key words

force variability - isometric - electromyography - coactivation
 

  • References

  • 1 Baratta R, Solomonow M, Zhou BH, Letson D, Chuinard R, D’Ambrosia R. Muscular coactivation. The role of the antagonist musculature in maintaining knee stability. Am J Sports Med 1988; 16: 113-122
    CrossrefPubMedGoogle Scholar
  • 2 Billot M, Simoneau E, Van Hoecke J, Martin A. Coactivation at the ankle joint is not sufficient to estimate agonist and antagonist mechanical ontribution. Muscle Nerve 2010; 41: 511-518
    CrossrefPubMedGoogle Scholar
  • 3 Billot M, Simoneau EM, Ballay Y, Van Hoecke J, Martin A. How the ankle joint angle alters the antagonist and agonist torques during maximal efforts in dorsi- and plantar flexion. Scand J Med Sci Sports 2011; DOI: 10.1111/j.1600-0838.2010.01278.x.
    PubMedGoogle Scholar
  • 4 Burnett RA, Laidlaw DH, Enoka RM. Coactivation of the antagonist muscle does not covary with steadiness in old adults. J Appl Physiol 2001; 89: 61-71
    PubMedGoogle Scholar
  • 5 Christou EA, Grossman M, Carlton LG. Modeling variability of force during isometric contractions of the quadriceps femoris. J Motor Behav 2002; 34: 67-81
    CrossrefPubMedGoogle Scholar
  • 6 Day SJ, Hulliger M. Experimental simulation of cat electromyogram: evidence for algebraic summation of motor-unit actionpotential trains. J Neurophysiol 2001; 86: 2144-2158
    PubMedGoogle Scholar
  • 7 Enoka RM, Christou EA, Hunter SK, Kornatz KW, Semmler JG, Taylor AM, Tracy BL. Mechanisms that contribute to differences in motor performance between young and old adults. J Electromyogr Kinesiol 2003; 13: 1-12
    CrossrefPubMedGoogle Scholar
  • 8 Fitts PM. The information capacity of the human motor system is controlling the amplitude of movement. J Exp Psychol 1954; 47: 381-391
    CrossrefPubMedGoogle Scholar
  • 9 Friden J, Lieber RL. Evidence for muscle attachment at relatively long lengths in tendon transfer surgery. J Hand Surg 1998; 23: 105-110
    CrossrefPubMedGoogle Scholar
  • 10 Gardner-Morse MG, Stokes IA. The effects of abdominal muscle coactivation on lumbar spine stability. Spine 1998; 23: 86-92
    CrossrefPubMedGoogle Scholar
  • 11 Graves AE, Kornatz KW, Enoka RM. Older adults use a unique strategy to lift inertial loads with the elbow flexor muscles. J Neurophysiol 2000; 83: 2030-2039
    PubMedGoogle Scholar
  • 12 Hamilton AF, Jones KE, Wolpert DM. The scaling of motor noise with muscle strength and motor unit number in humans. Exp Brain Res 2004; 157: 417-430
    PubMedGoogle Scholar
  • 13 Harris CM, Wolpert DM. Signal-dependent noise determines motor planning. Nature 1998; 20: 780-784
    PubMedGoogle Scholar
  • 14 Harriss DJ, Atkinson G. International Journal of Sports Medicine – Ethical Standards in Sport and Exercise Science Research. Int J Sports Med 2009; 30: 701-702
    Google Scholar
  • 15 Henneman E, Somjen G, Carpenter DO. Excitability and inhibitability of motoneurons of different sizes. J Neurophysiol 1965; 28: 599-620
    PubMedGoogle Scholar
  • 16 Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G. Development of recommendations for SEMG sensors and sensor placement procedures. J Electromyogr Kinesiol 2000; 10: 361-374
    CrossrefPubMedGoogle Scholar
  • 17 Jones KE, Hamilton AF, Wolpert DM. Sources of signal-dependent noise during isometric force production. J Neurophysiol 2002; 88: 1533-1544
    PubMedGoogle Scholar
  • 18 Jesunathadas M, Rudroff T, Enoka RM. Changes in muscle fascicles of tibialis anterior during anisometric contractions are not associated with motor-output variability of the ankle dorsiflexors in young and old adults. Eur J Appl Physiol 2010; 110: 1175-1186
    CrossrefPubMedGoogle Scholar
  • 19 Keen DA, Yue GH, Enoka RM. Training-related enhancement in the control of motor output in elderly humans. J Appl Physiol 1994; 77: 2648-2658
    PubMedGoogle Scholar
  • 20 Kong YK, Hallbeck MS, Jung MC. Crosstalk effect on surface electromyogram of the forearm flexors during a static grip task. J Electromyogr Kinesiol 2010; 20: 1223-1229
    CrossrefPubMedGoogle Scholar
  • 21 Laidlaw DH, Hunter SK, Enoka RM. Nonuniform activation of the agonist muscle does not covary with index finger acceleration in old adults. J Appl Physiol 2002; 93: 1400-1410
    PubMedGoogle Scholar
  • 22 Lieber RL, Friden J. Functional and clinical significance of skeletal muscle architecture. Muscle Nerve 2000; 23: 1647-1666
    CrossrefPubMedGoogle Scholar
  • 23 Lieber RL, Jacobson MD, Fazeli BM, Abrams RA, Botte MJ. Architecture of selected muscles of the arm and forearm: anatomy and implications for tendon transfer. J Hand Surg Am 1992; 17: 799-804
    CrossrefPubMedGoogle Scholar
  • 24 Loren GJ, Lieber RL. Tendon biomechanical properties enhance human wrist muscle specialization. J Biomech 1995; 28: 791-799
    CrossrefPubMedGoogle Scholar
  • 25 Salonikidis K, Amiridis IG, Oxyzoglou N, De Villareal E, Zafeiridis A, Kellis E. Force variability during isometric wrist flexion in highly skilled and sedentary individuals. Eur J Appl Physiol 2009; 107: 715-722
    CrossrefPubMedGoogle Scholar
  • 26 Semmler JG, Nordstrom MA. Motor unit discharge and force tremor in skill- and strength-trained individuals. Exp Brain Res 1998; 119: 27-38
    CrossrefPubMedGoogle Scholar
  • 27 Shinohara M, Yoshitake Y, Kouzaki M. Alterations in synergistic muscle activation impact fluctuations in net force. Med Sci Sports Exerc 2009; 191-197
    PubMedGoogle Scholar
  • 28 Simomeau EM, Billot M, Martin A, Van Hoecke J. Antagonist mechanical contribution to resultant maximal torque at the ankle joint in young and older men. J Electromyogr Kinesiol 2009; 19: e123-e131
    CrossrefPubMedGoogle Scholar
  • 29 Taylor AM, Christou EA, Enoka RM. Multiple features of motor-unit activity influence force fluctuations during isometric contractions. J Neurophysiol 2003; 90: 1350-1361
    CrossrefPubMedGoogle Scholar
  • 30 Tracy BL. Force control is impaired in the ankle plantarflexors of elderly adults. Eur J Appl Physiol 2007; 101: 629-636
    CrossrefPubMedGoogle Scholar
  • 31 Tracy BL, Mehoudar PD, Ortega JD. The amplitude of force variability is correlated in the knee extensor and elbow flexor muscles. Exp Brain Res 2007; 176: 448-464
    CrossrefPubMedGoogle Scholar
  • 32 Tracy BL, Enoka RM. Older adults are less steady during submaximal isometric contractions with the knee extensor muscles. J Appl Physiol 2002; 92: 1004-1012
    CrossrefPubMedGoogle Scholar
  • 33 Yao W, Fuglevand AJ, Enoka RM. Motor-unit synchronization increases EMG amplitude and decreases steadiness of simulated contractions. J Neurophysiol 2000; 83: 441-452
    CrossrefPubMedGoogle Scholar
  • 34 Yoshitake Y, Kouzaki M, Fukuoka H, Fukunaga T, Shinohara M. Modulation of muscle activity and force fluctuations in the plantarflexors after bedrest depends on knee position. Muscle Nerve 2007; 35: 745-755
    CrossrefPubMedGoogle Scholar