As we all know, with the increase of age, the elderly gradually appear hunchback and short stature, accompanied by hyperosteogeny and low back and leg pain. Moreover, the taller the person, the more obvious the height decline when he is older. Generally speaking, the height of people over 80 will be lower than that of young people 10 ~ 15 cm. According to Japanese data, when men are 60 years old, their height decreases by 1.5 cm and 3.5 cm respectively at the age of 65 and 75. The reason is that osteoporosis leads to vertebral compression fractures, vertebrae are pressed into wedges or thinned, and the support capacity of the spine is reduced and bent, so the figure is short. The spine is the longitudinal axis of the human body, which bears most of the weight of the human body and is the main part of the human body. Vertebra is almost entirely composed of cancellous bone, with a large number of endosteal surfaces, which can quickly transform metabolism, and the energy exchange rate is three times greater than that of dense bone, so osteoporosis appears the earliest, and the symptoms are most obvious in this part. There are two main conditions for the elderly to become short: ① their height is relatively low: osteoporosis is often accompanied by pathological fractures of the vertebral body, and the vertebral body collapses under pressure, which is wedge-shaped or flat, and the spine is kyphosis, resulting in "hunchback", inability to stand and relatively low height. The X-ray film of lumbar vertebra shows that the lumbar vertebra bone is coarse and loose, with longitudinal strip-like grid changes, and the density of vertebral body edge is increased, accompanied by labial hyperostosis. Moderately, the density of lumbar vertebral body is reduced, the texture is blurred, spinous process is proliferated, the vertebral body is narrowed, and the spinal canal is compressed. In severe cases, the bone density of lumbar spine is reduced, and bone texture is almost invisible, only the peripheral edge, vertebral compression fracture, flattening or double concave shape, anterior and posterior hyperplasia to form bone spurs, and spinal canal narrowing can be seen. Moreover, because the compression fracture of vertebral body is mainly caused by the weight of the support, it can also occur without external force or trauma. This kind of fracture is mostly formed without a history of trauma and severe pain, so the elderly unconsciously become shorter. ② Absolute height reduction: The elderly intervertebral disc is almost completely dehydrated, which leads to the reduction of the volume and thickness of the intervertebral disc, the shortening of the whole spine and the corresponding reduction of the height. When osteoclasts move in vivo, on the one hand, calcium and phosphorus are released from bone, on the other hand, calcium and phosphorus are deposited on surface bone tissue to form new bone. Under normal circumstances, these two processes are balanced. If bone remodeling is reduced, osteopenia will occur. If the following signs appear, such as low back pain, short height, spinal deformity (humpback), fracture and other clinical symptoms, it indicates osteoporosis. The risk factors of osteoporosis are: (1) age: age. (2) gender: female. (3) Race: Caucasian, Asian. (4) constitution: small and thin. (5) Menopause: premature delivery or ovariectomy. (6) Family history: positive. (7) Disease factors: various diseases that lead to physical weakness. (8) Life factors: smoking, drinking, little activity, insufficient intake of calcium and vitamin D, malnutrition. Among them, age is the main factor. Before the age of 70, the ratio of men to women is three to one, and after 70, the ratio of men to women is two to one. Actively preventing and treating osteoporosis and reducing the speed and degree of bone calcium loss in the elderly are the only measures to delay or reduce the shortening of the height of the elderly. Studies at home and abroad believe that adequate calcium supplementation, balanced nutrition and proper physical exercise can delay or reduce the loss of bone calcium. It is recommended to supplement calcium 1500mg at least every day. Timely and sufficient calcium supplementation to prevent the loss of bone calcium can not only prevent the fracture of the elderly, but also delay the shortening of the elderly, which is very necessary to maintain the health and strong physique of the elderly. Aging refers to the progressive aging or loss of certain functions and activities. This is a certain physiological phenomenon. For everyone, the performance of aging is different. However, it is the same phenomenon that people get shorter as they get older. Studies have shown that the main reason why people get older and shorter is that the spine becomes shorter. Because people's height is mainly composed of long bones of lower limbs and spine. The spine is located in the midline of the back and is the axial bone of the trunk. The spine has 33 vertebrae in childhood, but only 26 bones in adulthood due to the fusion of sacrum and coccyx. The length of the spine is relatively stable relative to the length of the lower limbs. The average length of the spine is about 70 cm for men and 65 cm for women, which varies with posture and age. The spine of the elderly is slightly shorter. Its length is related to the compression of intervertebral disc. Human body length changes in one day and night: the longest in the morning and the shortest in the evening, with a difference of 2-3 cm. When people get old, the thickness of intervertebral disc will be affected by aging. The intervertebral disc is located between the opposite faces of each pair of adjacent vertebral bodies, so that the two vertebral bodies are firmly connected. The intervertebral disc is slightly larger than the vertebral body, so it protrudes slightly between the vertebral bodies. It consists of fibrous ring and nucleus pulposus. The annulus fibrosus surrounds the nucleus pulposus, which is a kind of fibrous cartilage with annular cross arrangement, which is tough and elastic and can limit the protrusion of the nucleus pulposus. Nucleus pulposus is a white and elastic colloid. The intervertebral disc is firm and elastic, which can not only connect the vertebral body, but also bear the pressure, slow down the impact and protect the brain marrow, which is beneficial to the movement of the spine in all directions and increase the range of motion. When people reach middle age, the intervertebral disc gradually degenerates, and the glial fibers of nucleus pulposus and annulus fibrosus degenerate. This change is mainly manifested in the role of mucopolysaccharide protein in chondrocyte matrix, which leads to water reduction and even calcium salt deposition. Because cartilage has no blood vessels, the nutrient source of chondrocytes depends on the infiltration and diffusion of matrix. Then exchange materials with the blood vessels of cartilage periosteum. Due to the degeneration of cartilage matrix, the nutrient source of chondrocytes is blocked, glycogen in cytoplasm disappears, and then cells degenerate and die. The gradual decrease of chondrocytes and the pressure of matrix formation make the intervertebral disc gradually thinner. The elderly have hypogonadism, and sex hormones can promote the formation of cartilage fibers, so the growth and decline of sex hormones affect the growth and decline of cartilage, and hypogonadism will lead to slow growth of cartilage. With the increase of age, except the thinning of intervertebral disc, each vertebral body can gradually collapse due to osteoporosis. Osteoporosis is mainly due to the low level of sex hormones, the weakening of protein's anabolic stimulation, the decline of osteoblast function and the decrease of matrix formation. Reduced exercise and disused bone decalcification also played a role. Especially after menopause, although estrogen itself can not promote bone formation, it can antagonize the osteolytic effect of cortisol and parathyroid hormone. After menopause, estrogen level drops sharply, bone absorption accelerates, and osteoporosis gradually occurs. Vertebra support ability is insufficient, collapse becomes shorter after compression, and sometimes even compression fracture occurs. The shortening of the elderly is characterized by the obvious shortening of the trunk and the shortening of the limbs, so the main manifestation of the elderly is hunchback. Old people's muscle strength declines, it is more difficult to hold their chest and abdomen, and poor posture will also affect their height. Practice has proved that long-term physical exercise can reduce the occurrence of senile diseases and delay the aging process of the body. Developing a good posture in the early years also helps to overcome hunchback in the later years.