Anodal tDCS improves the effect of neuromuscular training on the feedforward activity of lower extremity muscles in female taekwondo athletes with dynamic knee valgus

Abstract

Transcranial direct current stimulation (tDCS) can increase cortical excitability of a targeted brain area. This study aimed to investigate the effect of adding anodal-tDCS (a-tDCS) to neuromuscular training (NMT) on the dynamic knee valgus (DKV) and feedforward activity (FFA) of knee muscles. Thirty-four Taekwondo athletes with DKV, were randomly assigned to either NMT + a-tDCS (N = 17) or NMT + sham tDCS (N = 17). DKV and the knee muscles' FFA at the moment of single and double-leg landing and lateral hopping tasks were evaluated before and after the interventions. DKV and FFA of the knee muscles was improved in all tasks (P < 0.05), however, between-group differences were not significant (P > 0.05). The FFA of the semitendinosus, vastus medialis, gluteus medius, and gastrocnemius muscles in the single-leg landing (P < 0.05), the gluteus medius, gluteus maximus, semitendinosus, biceps femoris, and gastrocnemius muscles in the double-leg landing (P < 0.05), and the gluteus medius, gluteus maximus, and gastrocnemius muscles in the lateral hopping (P < 0.05) tasks were significantly different between the groups. A-tDCS achieved significantly larger improvements in the feedforward activity of lower extremity muscles compared with sham-tDCS. However, between-group comparisons did not show a significant difference in DKV.