Lying upward arch lumbar lumbar spine pain, the possible causes of lumbar sprain, lumbar muscle strain, lumbar disc herniation. 1. lumbar sprain: may be the activities of the lumbar accidentally sprained, caused by the lumbar muscle pulling tear, appear lying upward arch lumbar spine part of the pain, more aggravating characteristics. 2. Lumbar muscle strain: may be due to the waist for a long time to maintain a certain position, resulting in lumbar muscle strain, lumbar tissue blood circulation is poor, resulting in lying upward arching lumbar vertebrae parts of the pain. 3. Lumbar disc herniation: may be due to the protruding disc compression of the nerves, most commonly seen in the high lumbar disc herniation, caused by lying upward arching lumbar spine part of the pain. Lying upward arching lumbar pain in the lumbar region may also have other reasons, it is recommended to go to the regular hospital in a timely manner, improve the relevant examination, clear cause, under the guidance of the doctor to give targeted treatment or treatment.