Possible reasons for leg lifting back pain include sports injury, lumbar muscle strain, lumbar disc herniation, etc. 1. Sports injury: after strenuous exercise, the muscles and tendons of the lumbar back are pulled repeatedly, which may cause mild injury and lactic acid accumulation, or the lumbar muscles are strained due to improper posture when carrying heavy objects, and the muscles are pulled when lifting the legs, which may cause pain, which will be gradually alleviated after resting. 2. Lumbar muscle strain: because of long-term bending work, improper posture, chronic strain, etc., resulting in lumbosacral muscle injury, aseptic inflammatory reaction, when we lift our legs, lumbosacral muscle contraction, muscle pulling stimulation, pain can occur. 3. Lumbar intervertebral disc herniation: Because of the degeneration of the intervertebral disc, the nucleus pulposus protrudes and can compress the nerve root at the back and cause lumbago. Lifting legs can cause positional changes, lumbar and hip muscle contraction, resulting in increased pressure in the spinal canal, thus aggravating the compression of the nucleus pulposus on the nerve root, causing pain. Causes of leg lifting low back pain is more, may also be related to lumbar dorsal fasciitis, pyriformis syndrome and other diseases, if the symptoms continue to be unrelieved, it is recommended to consult a doctor in a timely manner, to clarify the cause of the disease, and to carry out targeted treatment.