@Usha Rawat, my personal take on neutral spine is when a person is supine with the knees bent and feet flat and whatever position their personal lumbar spine and pelvis are in, is their CURRENT neutral. That means, they are not flexing nor extending the lumbar vertebrae or pelvis. Imprinted spine (for me) means that one is actively engaging the abdominals (and maybe the glutes) to press the lumbar vertebrae into the surface (if supine) or into a more flexed position than their neutral. I hope this clarifies better for you and please let me know if I can further answer any questions. Thank you. (I also sent this to you via personal message)