My husband and I were just given an orbitrek and want very much to use it, but it is set on the easiest setting and we can barely do a minute...There wasn't any instruction book with it and we don't know what to do with it...Should be just keep trying? also, have a hard time standing up straight. any suggestions? I have had a knee replacement and think that it would be great for me, but want to be cautious. thanks for any help!