Figure 28-13 The patient is in a semi-sitting position with the knees flexed slightly. The headrest support is fastened to the upper part of the table so that the head can be lowered without changing the relationship of the pinion head holder to the torso. The arms must be supported (not shown) so that the weight of the arm does not stretch the brachial plexus. The buttock area is padded. (Adapted from Martin JT: The head-elevated positions: Anesthesiologic considerations. In Martin JT [ed]: Positioning in Anesthesia and Surgery, 2nd ed. Philadelphia, WB Saunders, 1987, p 81.)