Leonardo da Vinci, The Abdomen and Leg of a Man, a drawing

This study of the left side of a nude man is mainly concerned with the highly-developed muscles of the thigh and calf; the foot and bottom are barely sketched in. It is probable that as well as sketching from life, Leonardo also dissected a dead body to gain information about the position of the muscles. Yet his skill lies in the ability to show how the muscles under the skin and flesh inform our knowledge of the whole body. Such knowledge of the human body is important for Leonardo's paintings. He understood how to build up the body from a skeleton with muscles and flesh, to the nude which he then clothed with drapery and set in dramatic action.The study is drawn in red chalk on salmon-pink prepared paper. Around this period Leonardo made quite a number of studies in red chalk on red paper. He began this 'red on red' technique in the 1490s with drawings for the Last Supper (Convent of Santa Maria delle Grazie (Refectory), Milan) and then continued with it in a series of botanical drawings for his lost picture of Leda and the Swan. He also made comparative studies with the legs of horses, studying both bone and muscle structure.