Kneeling, if possible. My arthritis sometimes prevents it. A lot depends upon where I am praying. If driving or riding the subway, obviously, I neither kneel nor prostrate myself. If in my tent, prostrate is best because I have my Sacred Heart statue hanging in the screen side pocket in front of me. I once saw a woman prostrate herself in the centre aisle at St. Patrick's Cathedral. I do not like to pass judgement, but she surely drew undue attention to herself as well as obstructed the aisle. After several prostrations, an usher told her to desist. She became angry and left out the side door onto 51 St. Normally, the prostrate position should be done in private or if the custom, in a group in a religious house.