Sarah "Crazy Sally" Mapp (baptised 1706 โ 1737) was an English lay bonesetter, who gained fame both by performing impressive bone-setting acts in Epsom and London, and by being a woman in a male-dominated profession. Bone-setting was a medical practice used to manipulate and fix musculoskeletal injuries using manual force. Mapp grew up in Wiltshire, England, and learned about the practice from her father, who was also a bone-setter. She frequently fixed horse racing injuries, but her most famous case was fixing the spinal deformity of Sir Hans Sloane's niece.