Lumbar easily sore and tired, sitting for a while or bending for a while will not be able to stand, may be lumbar degenerative changes, lumbar osteoporosis, lumbar muscle strain and other factors. 1. Degenerative changes of lumbar vertebrae: after the age increase, the lumbar vertebrae will have degenerative changes, which may induce osteoporosis and so on, and it is easy to cause lumbar soreness when sitting or bending for a long time. 2. Osteoporosis of lumbar vertebrae: when suffering from osteoporosis, when sitting, standing and bending for a long time, the phenomenon of lumbar soreness will occur, manifested as soreness, pain, and in severe cases, it will also lead to lumbar vertebrae compression fracture. 3. Lumbar muscle strain: it may be related to prolonged heavy physical labor or prolonged poor posture, etc., which can make the lumbar muscle chronic strain, bending or sitting for a long time will cause lumbar soreness and swelling, which may also be accompanied by obvious pain in the lumbar region. Lumbar easily sore and tired, sitting for a while or bending for a while will not be able to stand, it is recommended to consult a doctor for examination, after clarifying the causative factors, under the guidance of the doctor to carry out reasonable treatment.