膝部损伤后膝关节功能障碍患者股四头肌的表面肌电信号研究

Surface Electromyography of Quadriceps Femoris in Knee Injured Patients with Joint Dysfunction

目的探讨膝部损伤后膝关节功能障碍对股四头肌功能的影响。方法对23例单侧膝部损伤后膝关节功能障碍患者,膝屈曲30°,记录最大伸展等长收缩(MIVC)时的力矩,股外侧肌、股内侧肌和股直肌的表面肌电信号。结果在患侧膝屈曲30°膝最大伸展MIVC时的力矩,股外侧肌、股内侧肌和股直肌的平均肌电值(AEMG)、平均功率频率(MPF)、中位频率(MF)均低于健侧(P<0.01);健侧股外侧肌的AEMG、MPF大于股内侧肌、股直肌(P<0.01或P<0.05),股直肌大于股内侧肌(P<0.05);患侧股直肌的AEMG、MPF大于股外侧肌、股内侧肌(P<0.01或P<0.05);股外侧肌大于股内侧肌(P<0.05)。结论sEMG能够定量评价膝部损伤后膝关节功能障碍患者的肌肉功能。膝关节功能障碍患者患肢肌力及股四头肌受累肌肉活动水平显著降低,股直肌可能受影响程度较轻。

Objective To explore the quadriceps muscles function in patients with unilateral knee injury. Methods 23 unilateral knee injured patients with joint dysfuntion were assessed with isometric EMG activity of vastus lateralis （VL）, vastus medialis obliques （VMO） and rectus femoris（RF） of both thighs during three 5-s maximal isometric voluntary contractions at a knee joint angle of 30° （0° - full knee extension）, and the torque were recorded at same time. Results The average amplitude （AEMG）, mean power frequency （MPF）, and median frequency （MF） of VL, VMO and RF in affected knees were significantly lower than those in unaffected knees（P〈0.01）, as well as the torque（P〈0.01）. In the unaffected side, the AEMG, MPF of VL were higher than VMO and RF（P〈0.05）, and RF than VMO（P〈0.05）. In the affected side, the AEMG, MPF of RF are higher than VMO and VL（P〈 0.05）, and VL than VMO（P〈0.05）. Conclusion sEMG can provide quantitative measurements of muscle function. The isometric strength and neuromuscular activation lever are lower in affected limb, RF may he affected less than VL and VMO in knee injured patients with knee dysfunction.