Lying down and lifting legs does not damage the lumbar spine. 1. Under normal circumstances, sitting than standing lumbar spine to withstand the increased load, easy to cause lumbar degeneration, lumbar disc herniation. Lying down when the lumbar vertebrae bear the least load, the lumbar muscles are in a relaxed state, lying down and lifting the legs will not cause the lumbar muscles to be pulled not to increase the burden of the lumbar vertebrae, so the lumbar vertebrae is not damaged. 2. Lying down and lifting one leg can also increase the hip joints, sacroiliac joint mobility, lying down and lifting both legs can make the abdominal muscles taut, for the enhancement of abdominal muscle strength has a certain degree of help, muscle strength to enhance the stability of the lumbar vertebrae increased. Lying down to lift the leg does not damage the lumbar spine, usually can do straight leg exercise to increase the quadriceps exercise.