The drawings show a deep dissection of the right shoulder from behind and above. Leonardo had a fine appreciation of the ‘rotator cuff’ muscles surrounding the shoulder joint (subscapularis, supraspinatus, infraspinatus and teres minor), the four insertions of which are clearly shown attaching to the humeral head in the study at lower right. These drawings run as a sequence from upper right, turning the body slowly to end with a frontal dissected view at the bottom of the sheet. The sensitivity of modelling strongly suggests that they were drawn directly from life, though the stripping of the skin from the living muscles in the last drawing emphasises Leonardo’s powers of visualisation. Leonardo was aware that in death the muscles are relaxed, and that to obtain a true knowledge of their form he had to observe them in the living.