There are many causes of lumbar weakness, the main causes are lumbar meat atrophy, lumbar muscle strain, lumbar degenerative lesions, etc. 1, lumbar muscle atrophy: due to long-term bedridden can not be active resulting in lumbar muscle atrophy, get out of bed activities will feel lumbar weakness, prone to lumbar sprain; 2, lumbar muscle strain: prolonged sitting or standing, long-term ambulatory work, bending, etc. resulting in lumbar muscle fatigue, usually manifested as repeated episodes of lumbar soreness or swelling, can be radiated to the hip, the pain is severe, may limit muscle force; 3. Lumbar degenerative disease: mainly due to natural aging, excessive fatigue, muscle weakness, etc., resulting in lumbar disc protrusion, lumbar instability, in the force or force caused by the symptoms of lumbar weakness; 4, osteoporosis: osteoporosis more serious may be manifested as pain around the lumbar spine, can be manifested as no obvious cause of lumbar weakness; 5, other: systemic fever or tuberculosis infection and other diseases produce systemic poisoning symptoms In addition, long-term exertion causing kidney deficiency may also cause symptoms of lumbar weakness.