恢复期脑卒中患者大腿表面肌电变化与平衡功能的相关性

Relationship between the changes of surface electromyographic signal of thigh muscle and balance function in stroke patients

目的探讨脑恢复期卒中偏瘫患者膝屈伸最大等长收缩（MIVC）时大腿肌肉表面肌电sEMG信号变化及与平衡功能的相关性，为恢复期脑卒中患者的康复治疗提供理论指导。方法收集2008年6月至2009年月5间在中山大学附属第三医院康复科住院的21例脑卒中患者和18例年龄、性别相匹配的正常对照者。在膝关节屈伸MIVC时记录股内侧肌（VM）、股直肌（RF）、股外侧肌（VL）和股二头肌（BF）sEMG信号，采用Berg平衡量表（BBS）评估患者平衡功能。计算均方根值（RMS）、协同收缩率（CR）、膝关节屈伸力矩值及与BBS的相关性。结果患侧伸屈膝时VM、RF、VL及BF的RMS值[分别为（136±63）μV，（107±24）μV，（154±19）μV，（91±63））μV]小于正常对照及健侧RMS（P〈0．05），患侧屈膝CR值（43％±13％）大于健侧（37％±20％）及正常对照（32％±10％）CR值（P〈0．05）；患者BBS评分与患侧RF的RMS值呈正相关（r=0．53，P=0．01），与患侧BF的RMS值呈正相关（r=0．51，P=0．02）。与患侧下肢伸屈膝CR值呈负相关（CR伸=-0．59，P=0．005，CR月=0．41，P=0．046）。结论恢复期脑卒中患者双侧大腿前后肌群收缩功能及肌力均下降，患侧大腿伸肌痉挛仍存在。康复训练除抑制偏瘫肢体伸肌痉挛外，还应注重双侧大腿肌群尤其是患侧RF及BF力量训练，以提高膝关节稳定性和改善平衡功能。

Objective To explore the relationship between the changes of surface electromyography （sEMG） signal of thigh muscles and balance function in stroke patients during maximum isometric voluntary contraction （MIVC） of knee extension and flexion so as to provide rationales for rehabilitation. Methods Twenty-one stroke patients and 18 age-and sex-matched normal controls were recruited for this study. The surface electromyographic signals of of vastus medialis （VM）, rectus femoris （RF）, vastus lateralis （RL） and biceps feomris （BF） were recorded during MIVC of knee extension and flexion. Root mean square （RMS） and co-contraction ratio （CR） of both groups were compared and analyzed. The balance function was assessed by Berg balance scale （BBS）. Results There were significant differences in RMS of VM, RF, VL and BF of ipsilateral [ （136 ±63） μV, （107 ±24）μV, （154 ±19） μV, （91 ±63） μV], thigh during knee extension and flexion （P 〈 0. 05）. There were significant differences in CR on ipsilateral thigh muscles than the unaffected （43% ~ 13% vs 37% ＋20% ） and controls （43% ~ 13% vs 32% ~ 10% ） during knee flexion （ P 〈 0. 05 ）. The RMS of RF and BF on ipsilateral thigh was significantly positively correlated with the score of BBS （ rRF = 0. 53, P = 0. 01 vs rBF = 0. 51, P = 0.02） ; The CR of knee extension and flexion on ipsilateral thigh had a significantly negative correlation（ CRE = -0. 59, P = 0. 005 vs. CRF = -0. 41, P = 0. 046）. Conclusion The strength of bilateral thigh muscles decreases in stroke patients. The spasticity of thigh extensor still exists. Besides reducing the spasticity of hemiplegic limb extensor, rehabilitation should also focus upon bilateral thigh muscles, particularly ipsilateral RF and BF strength training to improve the knee joint stability and improve the balance function.