双侧大脑运动区经颅直流电刺激可提高双下肢最大输出功率

Transcranial direct current stimulations at bilateral brain motor areas elevate maximum output power of both lower limbs

背景:经颅直流电刺激技术做为一种新型的脑电刺激技术,被证明可以提高肌肉力量、有氧耐力及认知能力,而关于其是否能提高下肢功率输出能力的研究较少。目的:探究双侧大脑运动区单次阳极经颅直流电刺激对双下肢反向跳表现的影响。方法:招募了12名健康男性,年龄(24.25±1.21)岁,身高(175.91±4.60)cm,体质量(76.56±8.72)kg。采用随机双盲交叉设计,共进行2次试验,期间间隔7 d洗脱期,每次试验前均进行1次反向跳预测试,在2次试验中,所有受试者双侧大脑运动区随机接受2 mA,20 min阳极刺激或20 min假刺激,采集刺激后即刻以及刺激后1 h内每隔10 min时的跳跃高度和相对最大功率,以分析阳极刺激对健康男性反向跳的影响。采用Pearson相关分析检测2次预测试成绩的相关性,以判断试验的重测信度;采用重复测量方差分析比较两组别不同时段反向跳的跳跃高度和相对最大功率差异。研究的实施符合武汉体育学院对研究的相关伦理要求,伦理审批号为:2019006。受试者均自愿参加此次试验并签署知情同意书。结果与结论:①对于2次试验的重测信度,跳跃高度的相关系数为0.921(P<0.001),相对峰值功率的相关系数为0.938(P<0.001);②对于相对最大功率,组别主效应具有显著统计学意义(P<0.05,效应量为0.557),刺激组相对最大功率显著高于假刺激组(4.9%),组别与时间的交互效应以及时间主效应均无统计学意义(P>0.05,效应量分别为0.072和0.062);③对于跳跃高度,组别、时间及二者的交互作用均未发现统计学意义(P>0.05,效应量分别为0.088、0.196和0.069);④结果说明:20 min,2 mA双侧大脑运动区的阳性经颅直流电刺激后1 h内,健康成年男性下肢的最大输出功率提高。

BACKGROUND:Transcranial direct current stimulation technology is a new type of brain stimulation technique that has been proved to improve muscle strength,aerobic endurance,and cognitive ability.However,whether transcranial direct current stimulation can improve the ability of lower limb power output or not is less researched.OBJECTIVE:To investigate the effect of single-session anodal transcranial direct current stimulation at bilateral brain motor areas on countermovement jump performance.METHODS:Twelve healthy male college students,(24.25±1.21)years old,height:(175.91±4.60)cm,weight:(76.56±8.72)kg,were recruited.Randomized crossover design was used,and the subjects were randomly assigned to anode stimulating group or sham stimulating group.The experiment was conducted twice,with an departing interval of 7 days.All the subjects were given 2 mA anodal or sham stimulation for 20 minutes targeting the bilateral motor cortex.A countermovement jump test was conducted before each stimulation.Jump height and relative maximum power were recorded immediately after stimulation and every 10-minute intervals during 1 hour after stimulation,in order to analyze the effect of anodal stimulation on the countermovement jump of healthy men.Pearson’s correlation analysis was used to judge the test-retest reliability of the experiment,and repeated measurement variance analysis was used to compare the jump height and relative maximum power of the countermovement jump test between the two groups at different time periods.The implementation of the study complied with the relevant ethical requirements of Wuhan Sports University with an approval No.2019006.All the subjects voluntarily participated in the trial and signed an informed consent form.RESULTS AND CONCLUSION:For the test-retest reliability,the correlation coefficient of jump height was 0.921(P<0.001),and the correlation coefficient of relative maximum power was 0.938(P<0.001).For the relative maximum power,the main effect of the group was significant(P<0.05,pη^(2)=0.557).The relative maximum power of the stimulating group(4.9%)was significantly higher than that of the sham stimulating group.There were no significant differences in the interaction of group×time and the main effect of the time on the relative maximum power(P>0.05,pη^(2)=0.072 and 0.062).For the jump height,the interaction of group×time and the main effect of group and time had no significant difference(P>0.05,pη^(2)=0.088,0.196 and 0.069).These findings indicate that the maximum output power of lower extremities of healthy adult males is increased within 1 hour after anodal transcranial direct current stimulation(2 mA,20 minutes)at bilateral motor areas of the brain.