I. Epidemiology of low back pain (LBP) in the elderly Low back pain (LBP) is a group of syndromes, which is a symptom name rather than a disease name. It is a group of diseases characterized by low back pain and is divided into acute and chronic. The incidence is higher in the elderly. Many local and systemic diseases can present with low back pain, but clinically it is mostly caused by intraspinal canal diseases, extraspinal canal diseases, spinal degeneration and acute and chronic injuries; it is the most common complaint symptom in rehabilitation, orthopedics and neurology clinics, and at the same time, it is also a very common occupational disease. Its etiology is extremely complex, and there are many factors affecting it, so it is quite difficult to diagnose and treat. In developed countries, its prevalence can be as high as 60%?80%, and it is the second most common syndrome after upper respiratory tract disorders. About 97% of the causes of lower back pain are mechanical, 1% are non-mechanical, and 2% are visceral disease. The prevalence of low back pain in the United States is second only to upper respiratory tract infection, and the prevalence of low back pain in China is 11.5%, which is the first among orthopedic patients, and the trend is increasing in recent years. The main tissues that constitute the lumbar region are the lumbar fascia, muscles, lumbar vertebrae and their connections and intra-vertebral canal tissues. The muscles are the dynamic structure of the lumbar spine, and the cooperative action of each muscle produces flexion, extension, lateral bending and rotational movements. The fascia is the fixation and protection device of the muscles, and the lumbar vertebrae and their connections are the important components of the spine and the pillars of the lumbar tissues. The lumbar and sacral vertebrae are the most weight-bearing parts of the body, and they transfer the weight of the body above the waist and the stresses generated by movement to the pelvis and lower extremities. The lumbar spine is also the more active part of the human spine, with movement in the form of flexion, extension, left and right lateral bending and rotation. These two factors determine that the lumbar spine is the most vulnerable part of the injury, especially chronic strain lesions. When standing, the disc is subjected to greater pressure by the weight of the upper part of the body and the contraction force of the muscles of the lumbar back and abdomen that maintain the posture of the trunk, and the lower the disc is, the greater the pressure. Therefore, the incidence of lumbar disc herniation is highest in the lumbar 4-5 and lumbar 5-sacral 1 discs, reaching more than 90%. When the human body bends over, the intervertebral space narrows in front and opens up at the back, so the pressure on the fibrous ring is greater, and the fibrous ring is weaker on the back side, so the nucleus pulposus protrudes more to the back. As the intervertebral disc is often subjected to extrusion, twisting and other actions and the accumulation of minor injuries, the fibrous ring and the nucleus pulposus gradually undergo degenerative changes, manifesting as reduced water, increased protein, reduced sugar, reduced tension, weakened elasticity, increased brittleness and thinning of the intervertebral disc. Due to the high pressure on the intervertebral disc and the wide range of activities, when the disc metamorphoses and the elasticity of the fibrous ring is weakened, the fibrous ring is destroyed and the nucleus pulposus protrudes by the action of sudden and large external forces or repeated strain. The herniated nucleus pulposus stimulates or compresses the nerve root and dural sac, and corresponding neurological symptoms such as lumbar and leg pain and numbness appear. Therefore, lumbar disc herniation is often caused by certain injuries on the basis of degenerative changes in the intervertebral disc. Diagnosis and rehabilitation assessment is mainly based on complaints, nature of pain, physical examination, location of pressure points found by palpation, presence or absence of hard nodes, striae and pain excitation points in the pressure area, abnormalities in muscle strength and superficial skin sensation, etc., combined with imaging examinations such as X-ray, CT, MRI examination, etc. to make a comprehensive judgment. Other auxiliary examinations include EMG (electromyography), motor evoked potentials, balance test, etc. Rehabilitation assessment: the pain level, muscle strength, lumbar mobility, lumbosacral curvature, impact on work and life, etc. can be assessed. Single assessment (MMT, ROM-T, ADL-T) or comprehensive assessment can be performed. IV. Rehabilitation treatment for low back and leg pain