Tell me why people get old first when they get old.

In real life, we can find that many people look young and in good health when they are old, but leg problems always exist more or less. For example, the lower limbs are heavy, the knees are stiff, it is difficult to go up and down stairs, and even it is difficult to walk in the end. The old man trembled slightly when he walked, and the reason why he had to use crutches was that his legs and feet were not flexible. This is what we often say, "People get old when they get old." Then why "the old get old first"? The reason is that after the human body enters old age, all the body organs will gradually age, and the leg joints are the most used and loaded exercise organs in people's daily life. After decades of endurance and wear, they are more damaged than other organs, so they are the first to age. In medicine, this phenomenon of bone and joint aging caused by natural wear is called "degeneration of bone and joint", which is often called "old leg" The originally flexible and coordinated legs become clumsy and dull, and if you are not careful, you may step on the air and trip. The occurrence and development of "senile leg" is closely related to its etiology, and the most important thing is age. Medical research shows that the incidence rate of people over 50 years old accounts for 25% ~ 30%, and that of people over 60 years old accounts for 50% ~ 70%, among which the incidence rate of women is much higher than that of men, and the ratio of male to female is 1∶4, which is related to the decline of estrogen level and imbalance of calcium and phosphorus in women after menopause, leading to bone metabolism disorder. Secondly, obesity and osteoporosis can also lead to "old legs". But when people get old, they will definitely get "old legs". The key lies in reasonable diet and exercise. For example, women should pay attention to calcium supplementation, especially after menopause, and men should also supplement calcium after 50 years old. Eat more foods with high calcium content and get more sunshine. Usually, you should exercise moderately, such as walking slowly, and the intensity of the action should not be too great, so as not to be more unfavorable to bones and joints. For example, it is suggested that some women who love beauty should pay special attention to keeping their legs warm in cold winter, and don't let their legs suffer from cold for a long time just for the sake of beauty. Cold can cause joint damage, and there will be more leg problems in the elderly.