Amandine Bouguetoch1,2, Alain Martin3, Sidney Grosprêtre4. 1. Cognition, Action and Sensorimotor Plasticity [CAPS], INSERM U-1093, University of Bourgogne Franche-Comté-UFR STAPS, BP 27877, 21078, Dijon Cedex, France. amandine.bouguetoch@free.fr. 2. Cognition, Action and Sensorimotor Plasticity [CAPS], INSERM U-1093, Université de Bourgogne-UFR STAPS, BP 27877, 21078, Dijon Cedex, France. amandine.bouguetoch@free.fr. 3. Cognition, Action and Sensorimotor Plasticity [CAPS], INSERM U-1093, University of Bourgogne Franche-Comté-UFR STAPS, BP 27877, 21078, Dijon Cedex, France. 4. EA-4660 C3S Culture Sport Health Society, University of Bourgogne Franche-Comté, Besançon, France.
Abstract
INTRODUCTION: Cross education defines the gains observed in the contralateral limb following unilateral strength training of the other limb. The present study questioned the neural mechanisms associated with cross education following training by motor imagery (MI) or submaximal neuromuscular electrical stimulation (NMES), both representing a partial activation of the motor system as compared to conventional strength training. METHODS: Twenty-seven participants were distributed in three groups: MI, NMES and control. Training groups underwent a training program of ten sessions in two weeks targeting plantar flexor muscles of one limb. In both legs, neuromuscular plasticity was assessed through maximal voluntary isometric contraction (MViC) and triceps surae electrophysiological responses evoked by electrical nerve stimulation (H-reflexes and V-waves). RESULTS: NMES and MI training improved MViC torque of the trained limb by 11.3% (P < 0.001) and 13.8% (P < 0.001), respectively. MViC of the untrained limb increased by 10.3% (P < 0.003) in the MI group only, accompanied with increases in V-waves on both sides. In the NMES group, V-waves only increased in the trained limb. In the MI group, rest H-reflexes increased in both the trained and the untrained triceps suraes. CONCLUSION: MI seems to be effective to induce cross education, probably because of the activation of cortical motor regions that impact the corticospinal neural drive of both trained and untrained sides. Conversely, submaximal NMES did not lead to cross education. The present results emphasize that cross education does not necessarily require muscle activity of the trained limb.
INTRODUCTION: Cross education defines the gains observed in the contralateral limb following unilateral strength training of the other limb. The present study questioned the neural mechanisms associated with cross education following training by motor imagery (MI) or submaximal neuromuscular electrical stimulation (NMES), both representing a partial activation of the motor system as compared to conventional strength training. METHODS: Twenty-seven participants were distributed in three groups: MI, NMES and control. Training groups underwent a training program of ten sessions in two weeks targeting plantar flexor muscles of one limb. In both legs, neuromuscular plasticity was assessed through maximal voluntary isometric contraction (MViC) and triceps surae electrophysiological responses evoked by electrical nerve stimulation (H-reflexes and V-waves). RESULTS: NMES and MI training improved MViC torque of the trained limb by 11.3% (P < 0.001) and 13.8% (P < 0.001), respectively. MViC of the untrained limb increased by 10.3% (P < 0.003) in the MI group only, accompanied with increases in V-waves on both sides. In the NMES group, V-waves only increased in the trained limb. In the MI group, rest H-reflexes increased in both the trained and the untrained triceps suraes. CONCLUSION: MI seems to be effective to induce cross education, probably because of the activation of cortical motor regions that impact the corticospinal neural drive of both trained and untrained sides. Conversely, submaximal NMES did not lead to cross education. The present results emphasize that cross education does not necessarily require muscle activity of the trained limb.
Authors: J Decety; D Perani; M Jeannerod; V Bettinardi; B Tadary; R Woods; J C Mazziotta; F Fazio Journal: Nature Date: 1994-10-13 Impact factor: 49.962
Authors: Marius S Fimland; Jan Helgerud; Gerd Marie Solstad; Vegard Moe Iversen; Gunnar Leivseth; Jan Hoff Journal: Eur J Appl Physiol Date: 2009-09-16 Impact factor: 3.078