Anodal Transcranial Direct Current Stimulation Increases Muscular Strength and Reduces Pain Perception in Women With Patellofemoral Pain

Abstract

Rodrigues, GM, Paixão, A, Arruda, T, de Oliveira, BRR, Maranhão Neto, GA, Marques Neto, SR, Lattari, E, and Machado, S. Anodal transcranial direct current stimulation increases muscular strength and reduces pain perception in women with patellofemoral pain. J Strength Cond Res 36(2): 371-378, 2022-The purpose of this study is to investigate the effects of anodic transcranial direct current stimulation applied to motor cortex combined with open kinetic chain exercises on muscular strength and pain perception in women with patellofemoral pain (PFP). Twenty-eight women aged between 18 and 30 years with PFP were selected. Subjects were randomized in 2 groups, anodic stimulus plus resistance training (n = 14; anodic transcranial direct current stimulation [a-tDCS] + RT) or placebo stimulus plus resistance training (n = 14; Sham + RT) and attended the laboratory for 12 experimental sessions, 48-72 hours apart from each other. The RT protocol consisted of 3 sets of 12 repetitions of the knee extension exercise at 60% of 10 maximal repetition (10RM) with a 1-minute interval between sets. In the a-tDCS + RT group, a 2-mA current was applied for 20 minutes over the motor cortex before the RT protocol in each session. In the Sham + RT group, the stimulus was interrupted after 30 seconds. Preintervention, fourth session, eighth session, and postintervention, load was assessed through a 10RM test. The pain perception was assessed through Clarke sign maneuver (CSM) and measured through a visual analogue scale for pain. The a-tDCS + RT group showed greater 10RM load than Sham + RT group at eighth session (p < 0.05) and postintervention (p < 0.05). In a-tDCS + RT group, pain perception reduced in the postintervention compared with preintervention (p < 0.05). The intervention a-tDCS + RT was able to improve muscular strength in women with PFP. In addition, pain perception only decreased postintervention in the a-tDCS + RT group. This combined intervention can be used by coaches in rehabilitation programs aiming to treat PFP through medium-term strength gains.