Running, kicking, and tai chi are seemingly good ways to exercise, but they can actually be harmful to the knee joints of the elderly. Due to improper morning exercises, knee diseases among the elderly are on the rise, increasing by about 20% compared to the same period last year. A recently released survey of a sample of 1,400 middle-aged and older adults aged 65-75 showed that 74 percent of the elderly have knee disorders of varying degrees. Many elderly people focus too much on the exercise of their legs and joints during morning exercises and put their weight on the knee joints, which, together with the lack of muscle coordination, causes the cartilage of the knee joint surface to gradually wear away, leading to the occurrence of knee joint diseases. In the fall and winter morning exercise peak, the elderly should pay attention to the science of morning exercise, more upper limb exercise, change jogging to more walking, change kicking legs to more leg extension.