Can transcranial direct current stimulation improve range of motion and modulate pain perception in healthy individuals?

Abstract

The objective of the present study was to investigate the effects of different electrode assemblies and electric current polarity on the ROM of the hip and pain perception. Ten healthy male, sedentary, right-leg-dominant, and aged between 19 and 30 years (24.0 ± 4.0 years) subjects were recruited. For the experimental conditions, the application of transcranial direct current stimulation (tDCS) was performed with the following montages. In the montage 1, the cathodal electrode was placed over the motor cortex (MC) horizontally, and the anodal electrode was positioned over the left dorsolateral prefrontal cortex (DLPFC). In the montage 2, the anodal electrode was placed over the MC bilaterally, and the cathode electrode was positioned over the left DLPFC. The sham montage was the same as the montage 1. In the montage 1 and 2 stimulation was applied with 2 mA current intensity for 20 min. In the Sham condition, the stimulator was turned off after 30 s of active stimulation and the electrodes remained on the participants for 20 min. Before and after experimental conditions (Pre-stimulation, Post-stimulation), the maximum Hip ROM and pain perception was measured. For the Montage 1, the maximum Hip ROM increased in post-stimulation compared to pre-stimulation, and in the Montage 2, the maximum Hip ROM decreased in post-stimulation compared to pre-stimulation. The pain perception in the Montage 1 decreased in the post-stimulation compared to pre-stimulation. In the post-stimulation, pain perception for the Montage 1 was lower compared to Montage 2 (p = 0.005), and sham (p = 0.004). When the anodic stimulus was applied on the left DLPFC and the cathodic stimulus on the motor cortex, an increase in ROM and a reduction in the pain perception was observed. This montage may to modulate pain perception and joint flexibility.