There are two main reasons for this: the first one is that a long time posture causes compression of the legs, resulting in numbness of the blood supply and nerves and muscles, resulting in no sensation in the legs after getting up and getting out of bed, resulting in a fall, which will heal after rest and no sequelae. The second type of disease that middle-aged and elderly people should be alert to is a disease called TIA, which is called transient ischemic attack, due to the cerebrovascular disease of the transient blood supply, resulting in limb movement of the lower limbs is limited, and accompanied by limb weakness, but the time is relatively short, and quickly back to normal.