The role of the multifidus muscle is primarily to extend, rotate and stabilize the spine. The multifidus muscle in the normal human body belongs to the normal muscle tissue. Mainly located in the human body’s lumbar back, in the deep part of the erector spinae muscle, and the muscle is relatively thick, the muscle fibers are mainly longitudinal direction, very good to maintain the spine sagittal position smooth, and the muscle has a strong contraction ability to increase the muscle tension, so as to protect the spine, to maintain the stability of the spine. When the human body for bending weight-bearing activities, sedentary standing and other postures easily lead to polydactyl muscle injury, such as increased muscle tension, the production of inflammatory factors, the accumulation of acid, etc., can lead to polydactyl muscle aseptic inflammation, resulting in localized chronic, persistent pain, and in severe cases, it will affect the lumbar activities, clinically can be a clear diagnosis through ultrasound, magnetic resonance imaging and other tests. If you have lumbar pain or other physical discomfort, you need to consult a doctor in time to avoid delaying your condition.