| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
1 Department of Neurophysiology, Institute of Medical Physiology, and 2 Anatomy Department C, Panum Institute, 3 Copenhagen Muscle Research Centre, 4 Department of Medical Orthopaedics 7111 Rigshospitalet, and 5 Team Danmark Testcentre, Sports Medicine Research Unit, Bispebjerg Hospital, University of Copenhagen, DK-2200 Copenhagen, Denmark
Despite full voluntary effort, neuromuscular activation of the quadriceps femoris muscle appears inhibited during slow concentric and eccentric contractions. Our aim was to compare neuromuscular activation during maximal voluntary concentric and eccentric quadriceps contractions, hypothesizing that inhibition of neuromuscular activation diminishes with resistance training. In 15 men, pretraining electromyographic activity of the quadriceps muscles [vastus medialis (VM), vastus lateralis (VL), and rectus femoris (RF)] was 17-36% lower during slow and fast (30 and 240°/s) eccentric and slow concentric contractions compared with fast concentric contractions. After 14 wk of heavy resistance training, neuromuscular inhibition was reduced for VL and VM and was completely removed for RF. Concurrently, electromyographic activity increased 21-52, 22-29, and 16-32% for VL, VM, and RF, respectively. In addition, median power frequency decreased for VL and RF. Eccentric quadriceps strength increased 15-17%, whereas slow and fast concentric strength increased 15 and 8%, respectively. Pre- and posttraining median power frequency did not differ between eccentric and concentric contractions. In conclusion, quadriceps motoneuron activation was lower during maximal voluntary eccentric and slow concentric contractions compared with during fast concentric contraction in untrained subjects, and, after heavy resistance training, this inhibition in neuromuscular activation was reduced.
neuromuscular activation; muscle strength; neural efferent drive; eccentric activation deficiency; force inhibition
This article has been cited by other articles:
|
|
 |
|
  R. M. Crameri, P. Aagaard, K. Qvortrup, H. Langberg, J. Olesen, and M. Kjaer Myofibre damage in human skeletal muscle: effects of electrical stimulation versus voluntary contraction J. Physiol., August 15, 2007; 583(1): 365 - 380. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Duchateau, J. G. Semmler, and R. M. Enoka Training adaptations in the behavior of human motor units J Appl Physiol, December 1, 2006; 101(6): 1766 - 1775. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. Pasquet, A. Carpentier, and J. Duchateau Specific modulation of motor unit discharge for a similar change in fascicle length during shortening and lengthening contractions in humans J. Physiol., December 1, 2006; 577(2): 753 - 765. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. L Andersen, S P. Magnusson, M. Nielsen, J. Haleem, K. Poulsen, and P. Aagaard Neuromuscular Activation in Conventional Therapeutic Exercises and Heavy Resistance Exercises: Implications for Rehabilitation Physical Therapy, May 1, 2006; 86(5): 683 - 697. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Duclay and A. Martin Evoked H-Reflex and V-Wave Responses During Maximal Isometric, Concentric, and Eccentric Muscle Contraction J Neurophysiol, November 1, 2005; 94(5): 3555 - 3562. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. L. Andersen, J. L. Andersen, S. P. Magnusson, C. Suetta, J. L. Madsen, L. R. Christensen, and P. Aagaard Changes in the human muscle force-velocity relationship in response to resistance training and subsequent detraining J Appl Physiol, July 1, 2005; 99(1): 87 - 94. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. G. M. Beltman, A. J. Sargeant, W. van Mechelen, and A. de Haan Voluntary activation level and muscle fiber recruitment of human quadriceps during lengthening contractions J Appl Physiol, August 1, 2004; 97(2): 619 - 626. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. KJAeR Role of Extracellular Matrix in Adaptation of Tendon and Skeletal Muscle to Mechanical Loading Physiol Rev, April 1, 2004; 84(2): 649 - 698. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Babault, M. Pousson, A. Michaut, and J. Van Hoecke Effect of quadriceps femoris muscle length on neural activation during isometric and concentric contractions J Appl Physiol, March 1, 2003; 94(3): 983 - 990. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Aagaard, E. B. Simonsen, J. L. Andersen, P. Magnusson, and P. Dyhre-Poulsen Increased rate of force development and neural drive of human skeletal muscle following resistance training J Appl Physiol, October 1, 2002; 93(4): 1318 - 1326. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
E. A. Christou and L. G. Carlton Age and contraction type influence motor output variability in rapid discrete tasks J Appl Physiol, August 1, 2002; 93(2): 489 - 498. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Aagaard, E. B. Simonsen, J. L. Andersen, P. Magnusson, and P. Dyhre-Poulsen Neural adaptation to resistance training: changes in evoked V-wave and H-reflex responses J Appl Physiol, June 1, 2002; 92(6): 2309 - 2318. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. A. Maffiuletti, M. Pensini, and A. Martin Activation of human plantar flexor muscles increases after electromyostimulation training J Appl Physiol, April 1, 2002; 92(4): 1383 - 1392. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
