Occasional half lying on the lumbar spine has no particular impact, regular half lying may lead to lumbar pain, and even induce lumbar disc herniation.
Under normal circumstances, the lumbar spine has its own specific physiological curvature arc, lying down the lumbar intervertebral disc pressure is minimized, half-lying will make the upper body’s strength completely in the lumbar vertebrae pressure point, so that the original physiological arc changes, occasional half-laying will not cause significant discomfort, but prolonged half-laying is prone to lead to pain in the lumbar region.
Frequent half lying will lead to physiological curvature straightening, so that the lumbar intervertebral disc force increases, easily lead to lumbar intervertebral disc herniation, herniated lumbar intervertebral disc may compress the nerve root, which leads to lumbar and hip and lower limb pain, numbness and so on.