Answers:
If you stand near your knees locked (legs completely straight and immobile), it can affect the return circulation to your heart, and you can become giddy.
IT medium when you stand up and on edge your knees up so your knee cup cannot move and it is up and you lock it oin similar to that it will affect your circulation because the blood cannot circulate around your knees because they are locked within. Therefore, you will go by out.