A device for stabilizing a human patient on an operating table with which the device is intended to be used, the operating table having a width and a length, the device comprising: a generally planar support having a body portion and on either side of the body portion a left arm wing and a right arm wing, the support having opposed superior and inferior edges, opposed left and right lateral edges and an opposed top and bottom; wherein: the body portion extends from the superior edge to the inferior edge, the inferior edge defining a notch indented into the body portion; the left and right arm wings extend along the left and right lateral edges respectively; the body portion has a lateral width substantially equal to the width of the operating table; the support has a lateral width greater than the width of the operating table; the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, and the patient is supine on the body portion, then the patient's left and right arms can rest on the left and right arm wings respectively; and the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, the patient is supine on the body portion, and the patient's shoulders are aligned with the superior edge of the body portion, then the patient's perineum can be positioned above the notch and the patient's hands can lie superior to the inferior edge; the device further comprising a left and a right arm sheet fixedly attached to the bottom of the left and right arm wings respectively, the left and right arm sheets extending laterally beyond the left and right lateral edges respectively; and an immobilizing fastener configured to secure the support to the operating table; characterized in that: the device further comprises left and right support structures fixedly attached to the bottoms of the left and right arm wings respectively, the left and right support structures offering substantially no resistance to folding the left and right arm wings respectively toward the top, but offering resistance to folding the left and right arm wings respectively toward the bottom. a generally planar support having a body portion and on either side of the body portion a left arm wing and a right arm wing, the support having opposed superior and inferior edges, opposed left and right lateral edges and an opposed top and bottom; the body portion extends from the superior edge to the inferior edge, the inferior edge defining a notch indented into the body portion; the left and right arm wings extend along the left and right lateral edges respectively; the body portion has a lateral width substantially equal to the width of the operating table; the support has a lateral width greater than the width of the operating table; the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, and the patient is supine on the body portion, then the patient's left and right arms can rest on the left and right arm wings respectively; and the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, the patient is supine on the body portion, and the patient's shoulders are aligned with the superior edge of the body portion, then the patient's perineum can be positioned above the notch and the patient's hands can lie superior to the inferior edge; the support has a lateral width greater than the width of the operating table; the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, and the patient is supine on the body portion, then the patient's left and right arms can rest on the left and right arm wings respectively; and the support is sized and shaped such that when the support is laid flat with its bottom on the operating table, the patient is supine on the body portion, and the patient's shoulders are aligned with the superior edge of the body portion, then the patient's perineum can be positioned above the notch and the patient's hands can lie superior to the inferior edge; the device further comprising a left and a right arm sheet fixedly attached to the bottom of the left and right arm wings respectively, the left and right arm sheets extending laterally beyond the left and right lateral edges respectively; and the device further comprises left and right support structures fixedly attached to the bottoms of the left and right arm wings respectively, the left and right support structures offering substantially no resistance to folding the left and right arm wings respectively toward the top, but offering resistance to folding the left and right arm wings respectively toward the bottom.