Lying down always feel the inner surface of the back waist jump consider muscle strain, soft tissue infection, lumbar intervertebral disc herniation and so on. 1. Muscle strain: If you often sit for a long time in daily life or often do tired work can cause lumbar muscle strain, causing muscle spasms, so you will feel the lumbar internal surface jumping. You can relax the lumbar muscles with massage, or take oral muscle relaxation drugs such as Cloxazone or Eperisone. 2. Soft tissue infection: lumbar muscle or soft tissue gap infection pus will also appear lumbar internal surface jumping, there will be obvious pain, lumbar spine activity is limited, take anti-infection treatment or incision and drainage. 3. Lumbar disc herniation: Lumbar disc herniation compressing the nerves can also lead to lumbar internal surface jump after lying down, can be treated with methylcobalamin and other nutritive drugs for the nerves. It is best to go to the hospital to check the cause of the problem when you lie down, and then treat the cause of the problem.