不同负荷水平颈部肌肉等长收缩的平均肌电变化特征

The Changes of AEMG of Neck Muscles Under Isometric Contraction at Different Load Levels

目的:采用表面肌电信号(Surface Electromyographic Signal,sEMG)分析技术研究不同负荷水平颈部两侧头夹肌、胸锁乳突肌和斜方肌上部肌肉等长收缩对相关肌肉平均肌电((Average EMG,AEMG)活动的影响,为进一步开展颈部肌肉功能和康复训练效果评价提供科学依据。方法:16名无颈部疾病的健康青年男性志愿者,分别在颈椎屈曲、后伸、左侧屈和右侧屈4个运动方向上完成20%最大随意收缩力(Maxi mal Voluntary Contraction,MVC)、40%MVC、60%MVC、80%MVC和100%MVC的等长收缩实验,期间采集被检肌肉的sEMG信号,计算标准化的AEMG。结果:①受试者最大颈椎后伸力量显著大于颈椎屈曲、颈左侧屈及右侧屈力量,而后三者之间没有显著差异;②递增负荷水平等长收缩条件下与运动方向同侧的颈部肌肉出现收缩增强效应,而对侧拮抗肌表现出明显的共收缩现象;③运动方向和负荷水平均对各被检肌肉的AE-MG有明显作用,且以上两因素对各被检肌肉AEMG有明显交互作用。结论:人体颈部最大伸颈力量显著大于屈颈、颈左侧屈和右侧屈力量,完成矢状面屈伸和额状面侧屈运动时各被检肌肉的AEMG值与负荷水平成正比。

To provide scientific evidences for evaluating the neck muscle function and rehabilitation training effect,this study employed sEMG analysis technology to investigate the bilateral splenius capitis,sternocleidomastoid and upper trapezius muscles＇ activities when subjects made isometric contractions with different levels of non-fatigue loads.Method： Sixteen young healthy volunteers performed isometric neck flexion,extension,left flexion and right flexion under 20%,40%,60%,80% and 100% maximal voluntary contraction（MVC） respectively.The sEMG signals of target muscles were gathered and normalized average electromyography（AEMG） were calculated.Results：①The maximal strength of neck extension was significantly higher than that of neck flexion,of neck left flexion and of neck right flexion.The latter three flexion strengths displayed no remarkable difference.②The electromyographic activities of contracting neck muscles increased with increasing work load.And the contra lateral muscles showed significant ＂co-activation effect.＂ ③There were marked effects of contracting direction and load level on AEMGs of these investigated muscles.The interaction effect of two factors（direction and level） upon AEMGs of these muscles was significant.Conclusions：The maximal strength of neck extension was remarkably higher than that of other three direction contractions.AEMGs of investigated muscles were proportioned to load level when subjects performed neck extension and flexion in sagittal plane and lateral flexion in frontal plane.