I read the post; it is here, in the correct place, two posts above this one. Scroll up or down; using the slider bar on the right by putting your mouse on it and holding down the left arrow key and dragging it up and down; or use your up and down arrow keys on the key board; or page up and page down keys; 3 differant ways to display the rest of the current page.
In time you will figure out this board, and the various forums, keep clicking on things, you can't break it. If you make a mistake, like posting a topic in the wrong forum, the Moderator Team can correct it, move it to a more suitable forum. We are here to help. If you have questions, just ask. We have one forum dedicated to that: Board Announcements And/Or Questions. You may find those topics helpful.
I read your post and understand it, as well as having a better understanding of the problem with your knees.