Bankoff A D P, Gushi M S, Boer N P
Electromyography and Biomechanics of Posture Laboratory, Physical Education Faculty, State University of Campinas, Unicamp, São Paulo, Brazil.
Electromyogr Clin Neurophysiol. 2007 Jan-Feb;47(1):49-54.
The purpose of this work was to register the electromyography data of the muscles brachialis, biceps brachii long portion, biceps brachii short portion and brachioradialis in the movements of elbow flexion, in the "Larry Scott" bench, in supination and pronation positions, in weightlifting trained subjects. Ten male right-handed subjects were selected, with at least one-year experience in weightlifting exercises, without previous neuromuscular diseases, age between 21 and 26 years. After taking the "Maximum Load" (M.L.) test, or a maximum repetition, we had the percent pattern to establish the loads used in the tests, which was 80%0 of the M. L. For the electromyography records was used a six-channel electromyography (lynx) and the AqDados software in four different moments for each subject: an isometric phase lasting five seconds in supination (1), keeping a 90 degrees angle between the arm and forearm; another one in isometric pronation (2); ten repetitions lasting fifty seconds in supination (3); and ten repetitions in pronation (4). The results of the normalization showed a level of similar activation between the involved muscles in one same moment, as much in supination as in pronation. From the analysis of variance ANOVA, having as level of significance p < 0,05, concludes that it did not have significant difference in the performance of these muscles. When compared between itself all the values of p were bigger than 0,05. Of this form we can perceive a joint action of all the flexion muscle of the elbow to resist the load imposed during the effort.
这项工作的目的是记录举重训练受试者在“拉里·斯科特”长凳上进行肘部屈曲、旋前和旋后动作时肱肌、肱二头肌长头、肱二头肌短头和肱桡肌的肌电图数据。选取了10名右利手男性受试者,他们至少有一年的举重练习经验,既往无神经肌肉疾病,年龄在21至26岁之间。在进行“最大负荷”(M.L.)测试或最大重复次数测试后,我们根据百分比模式确定测试中使用的负荷,即M.L.的80%。对于肌电图记录,使用了六通道肌电图仪(猞猁)和AqDados软件,在每个受试者的四个不同时刻进行记录:在旋前时进行一次持续5秒的等长收缩阶段(1),保持手臂和前臂之间成90度角;另一次在旋后时进行等长收缩(2);在旋前时进行10次持续50秒的重复动作(3);以及在旋后时进行10次重复动作(4)。归一化结果显示,在同一时刻,无论是旋前还是旋后,所涉及肌肉之间的激活水平相似。从方差分析(ANOVA)来看,显著性水平p<0.05,得出这些肌肉的表现没有显著差异的结论。当对所有p值进行相互比较时,均大于0.05。由此我们可以察觉到,肘部所有屈肌共同发挥作用以抵抗用力过程中施加的负荷。