Author(s): GONZÁLEZ, I.M., COLOMER-POVEDA, D., SÁNCHEZ-MOLINA, J.A., MARCOS-FRUTOS, D., BOTANA-LÓPEZ, L., MORENILLA-BURLÓ, L., BOUZA-MÉNDEZ, K., MÁRQUEZ, G., LÓPEZ-ALONSO, V. , Institution: UNIVERSITY OF A CORUÑA, Country: SPAIN, Abstract-ID: 2478

INTRODUCTION:
Transcranial direct current stimulation (tDCS) is a safe, non-invasive, pain-less type of stimulation that has been used with the aim to influence different aspects of gross motor performance. The main objective of this study was to verify the acute effect of a single session of tDCS applied to the primary motor cortex (M1) or the dorsolateral prefrontal cortex (DLPFC), on maximum strength, endurance, neurophysiological and perceptual parameters, in a manual hand-grip task in healthy young adults.
METHODS:
The study follows a randomized, controlled, triple-blind, crossover design with a placebo condition. The sample comprised 42 healthy university students (21.52±1.40 years; 19 women). Maximal strength, corticospinal excitability and intracortical inhibition and facilitation were assessed before and after the application of 20 minutes of 2mA tDCS (M1, DLPFC or Sham). After tDCS, the number of maximum contractions performed until a 30% loss of hand-grip maximum strength was recorded.
RESULTS:
No effect was detected on maximal strength, corticospinal excitability, intracortical inhibition and facilitation, the number of repetitions done until a 30% of maximum strength loss and perception of effort following the administration of tDCS over M1 and DLPFC.
CONCLUSION:
The results of the present study suggest that tDCS over M1 or DLPFC does not influence corticospinal and intracortical structures and has no effect over maximum strength nor the ability to repeat maximum contractions. The absence of corticospinal and intracortical changes precludes to link the response pattern between functional and neurophysiological variables. Further research is needed to determine under what conditions or tasks tDCS could potentially benefit gross motor performance before its recommendation as a tool aimed at optimizing performance during motor tasks.