On another post, someone asked for suggestions on what we do to "reach" the knee lifter. Though mine are both adjustable, they still aren't a comfortable reach. This was a suggestion I picked up somewhere, and it's worked marvelously and comfortably. Cut an 8" length of flexible swimming pool noodle and slide it onto the blade of the knee lifter. It stays snugly in place and is firm enough to take knee pressure and not compress/flatten.

Jan in MD