Tightness of the legs generally refers to stiffness of the legs. Stiffness of the legs 3 months after cervical spine surgery may be due to spinal cord injury, lumbar intervertebral disc herniation, cerebrovascular lesions, etc., which need to be specifically analyzed. 1. Spinal cord injury: If the spinal cord is damaged during cervical spine surgery, the function of the spinal cord in transmitting nerve impulses will be abnormal, which will be manifested as stiffness in both legs. 2. Lumbar disc herniation: If the patient has a lumbar disc herniation after the surgery, it will exert pressure on the local nerves and lead to stiffness in both legs. 3. Cerebrovascular lesions: If the patient has a cerebral thrombosis, it will affect the blood perfusion to the brain cells, which will cause dysfunction in the area dominated by the brain, and will be manifested as stiffness in the legs. When patients have stiff legs after cervical spine surgery, it is recommended that they go to the hospital in time, and under the guidance of the doctor to carry out standardized treatment to promote the alleviation of the condition.