Vertebral canal surgery three months lying down no pain walking soreness consider vertebral instability, nerve compression, muscle atrophy. 1. Vertebral instability: after spinal canal surgery, it is easy to cause instability of the adjacent vertebrae, and the nerve is not compressed when lying down, and when walking on the ground, the vertebrae are displaced and compress the nerves and spinal cord, resulting in leg pain. 2. Nerve compression: After spinal canal surgery, the nerve is easily relapsed, and the nerve is compressed again, resulting in leg pain. 3. Muscle atrophy: Considering too much time in bed after the surgery or not exercising the lumbar muscles causes muscle atrophy and weakness, and when walking there is soreness. Vertebral canal surgery three months lying down does not hurt walking sore, need to go to the hospital to review, if necessary, take an MRI film to clarify the specific causes.