Modulation of Isometric Quadriceps Strength in Soccer Players With Transcranial Direct Current Stimulation: A Crossover Study

Abstract

Vargas, VZ, Baptista, AF, Pereira, GOC, Pochini, AC, Ejnisman, B, Santos, MB, João, SMA, and Hazime, FA. Modulation of isometric quadriceps strength in soccer players with transcranial direct current stimulation: a crossover study. J Strength Cond Res 32(5): 1336-1341, 2018-The aim of this study was to evaluate the effect of transcranial direct current stimulation (tDCS) on the maximum isometric muscle contraction (MVIC) of the knee extensors in soccer players at the preprofessional level. Twenty female soccer players aged 15-17 years (mean = 16.1; SD = 0.9) with 5.2 ± 2.6 years of training were randomly divided into 2 groups to receive either active or sham tDCS in a single session (2 mA; 0.057 mA·cm). The MVIC of the knee extensors was evaluated in both lower limbs by manual dynamometry in 5 sets of contractions divided into 4 blocks: (a) prestimulation, (b) during tDCS, (c) 30 minutes after tDCS, and (d) 60 minutes after tDCS. After an interval of 7 days, the groups were evaluated again, and the type of initial stimulation was inverted between participants. The MVIC of the knee extensors increased significantly during active tDCS (dominant limb (DL) = 0.4; IC = 0.1-0.8 N·Kg), 30 minutes after active tDCS (DL = 0.9; IC 0.4-1.4 N·Kg), and 60 minutes after active tDCS (DL = 1.0; IC 0.3-1.6 N·Kg) but not for sham tDCS. Our conclusion was that tDCS temporarily increases isometric quadriceps strength in adolescent female soccer players, which may be useful for both strength training and rehabilitation.

The Immediate Effects of Transcranial Direct Current Stimulation on Quadriceps Muscle Function in Individuals With a History of Anterior Cruciate Ligament Reconstruction: A Preliminary Investigation

“…When compared with the sham tDCS, the active tDCS improved MVIC during, 30 minutes post, and 60 minutes post treatment by 5.2%, 6.3%, and 9.4% in the dominant limb. 31 Unlike Vargas et al 31 who utilized healthy individuals, isometric strength values in our study decreased for the tDCS (8.9% decrease) and sham (10.1% decrease) conditions after 20 minutes of walking (d = 0.12; CI, −0.76 to 1.00). This decrease in torque may be the result from the active recovery following the pretesting.…”

“…Vargas et al 31 examined the effects of tDCS on MVICs of the quadriceps in a healthy group of soccer players, which included an active and a sham session while measuring 5 different MVICs at different time points post-tDCS/sham condition. When compared with the sham tDCS, the active tDCS improved MVIC during, 30 minutes post, and 60 minutes post treatment by 5.2%, 6.3%, and 9.4% in the dominant limb.…”

Cerebellar Transcranial Direct Current Stimulation Improves Maximum Isometric Force Production during Isometric Barbell Squats

“…tDCS has been used to uncover neural links between muscle strength and related brain areas through modulating their excitability. Accordingly, numerous studies have demonstrated tDCS related increases in muscle strength endurance [9][10][11] and MIVC [12][13][14], particularly for upper extremities. Lower extremity muscle strength modulation has also been assessed through tDCS application, although results are rather inconclusive.…”

Neurodiagnostics in Sports: Investigating the Athlete’s Brain to Augment Performance and Sport-Specific Skills

“…Several opinion papers and systematic review and meta-analysis articles discussed the feasibility of tDCS as a performance enhancer in athletes (Bolognini et al, 2009;Banissy and Muggleton, 2013;Davis, 2013;Reardon, 2016;Edwards et al, 2017;Angius et al, 2018b;Machado et al, 2019). Interestingly, tDCS is capable of increasing isometric strength (Hazime et al, 2017;Vargas et al, 2018), countermovement jump performance (Lattari et al, 2020) and endurance performance (Okano et al, 2015) even in trained athletes. These findings indicate that tDCS, if suitably applied, might potentially have positive effects on the athlete's performance.…”