恢复期脑卒中患者膝关节拮抗肌群在动态运动负荷下对协同收缩率的影响

目的观察动态运动负荷对脑卒中患者膝关节拮抗肌群协同收缩率变化的影响。方法11例脑卒中患者(偏瘫组)和14例正常人(正常组)利用动态运动负荷诱发双侧下肢屈伸膝关节,采用表面电极引导和记录肌电信号并进行线性时、频分析。结果偏瘫组与正常组组内中位频率(MF)、平均功率频率(MPF)、平均肌电值(AEMG)膝关节拮抗肌群协同收缩率均值变化无显著性差异(P>0.05);组间比较,MF膝关节拮抗肌群协同收缩率均值变化无显著性差异(P>0.05);偏瘫组MPF膝关节拮抗肌群协同收缩率明显增高,AEMG膝关节拮抗肌群协同收缩率明显降低(均P<0.01)。结论MPF、AEMG膝关节拮抗肌群协同收缩率能反映动态运动负荷下脑卒中患者下肢肌肉表面肌电信号变化,而MF膝关节拮抗肌群协同收缩率并不能很好地反映动态运动负荷下脑卒中患者下肢肌肉表面肌电信号变化。

Effect of Dynamic Contractions on sEMG Co-contraction Ratio Taken from Antagonist Muscles of Knee Joint in Stroke Patients at Convalescence Stage

Objective To observe the influence of dynamic contractions on the sEMG co-contraction ratio taken from the antagonist muscles of the knee joint of stroke patients.Methods 11 stroke patients and 14 healthy subjects were measured the dynamic contractions in both knee flexion and extension with the surface electromyography(sEMG).Results There was no significant differences of the median frequency(MF),mean power frequency(MPF),average EMG(AEMG)and the sEMG co-contraction ratio within the stroke patients and the healthy(P>0.05).There was no significant difference of the MF between the patients compared with the healthy(P>0.05),but the sEMG co-contraction ratio of the MPF increased significantly and that of AEMG decreased significantly(P<0.01).Conclusion The MPF,AEMG and the sEMG co-contraction ratio taken from the stoke patients may reflect the characters of the low limb muscle and the MF may not.