quadratus muscle quadratus muscle quadratus is latin for square and quadratus muscle may refer to: depressor labii inferioris muscle, also known as musculus quadratus labii inferioris levator labii superioris muscle, also known as musculus quadratus labii superioris pronator quadratus, a square shaped muscle on the distal forearm that acts to pronate (turn so the palm faces downwards) the hand quadratus femoris muscle, a flat, quadrilateral skeletal muscle. located on the posterior side of the hip joint quadratus lumborum muscle, a muscle of the posterior abdominal wall quadratus plantae muscle, a muscle in the foot this article is issued from wikipedia. the text is licensed under creative commons - attribution - sharealike. additional terms may apply for the media files.