Abstract:[Objective] To quantitatively evaluate the surface electromyography (sEMG) changes in multi-exercises for facet disorder before and after lumbar oblique wrench manipulation. [Methods] From September 2020 to December 2021, 15 patients with facet disorder and 10 matched normal subjects were included in this study in the Department of Tuina, Ruijin Hospital affiliated to Shanghai Jiao Tong Uni- versity. The clinical score evaluation and sEMG under several exercise states were conducted before and after lumbar oblique wrench manip- ulation. The difference in clinical state and the myoelectric activity of lumbar muscles were compared before and after lumbar oblique wrench manipulation in the patient with the normal subject. [Results] Compared with those before treatment, the VAS score for pain signifi- cantly reduced [(6.2±0.9), (1.5±0.6), P＜0.05], while the JOA score significantly increased [(11.9±1.4), (22.7±3.3), P＜0.05] 1 month after treatment in the patients. In terms of sEMG, the mean amplitude and median frequency of the right and left erector, as well as the left and right multifidus significantly decreased 1 month after treatment compared with those before treatment under different exercise modes, includ- ing normal walking, right foot over obstacle, left foot over obstacle, bending and bending load (P＜0.05). After treatment, the mean sEMG am- plitude and median frequency of right and left erector and left and right multifidus were not significantly different from those of normal peo- ple (P＞0.05). [Conclusion] Lumbar oblique wrench manipulation does relieve pain and reduce the abnormal electrical activity of erector and multifidus muscles in patients with facet disorders.