Understanding the virtue of a curved heel for improvement in defections of gait and posture is but one example of Thomas' application of anatomy and physiology to the practice of orthopedics. The Thomas posterior or hip splint for immobilization of the hip, the Thomas knee splint for immobilization of this structure, the Thomas caliper for ambulating patients, Thomas' sign for diagnosis of disease of the hip, the Thomas wrench, the behavioral correction of dislocations of the ankle joint and hip, and reduction of Pott's fracture of the ankle are other contributions which remain currently in favor.
Thomas was born in Bodedern, Anglesey, in Wales, while his mother was on a visit to her parents.1 His father, following the bone-setter trade of his ancestors, had set up practice in Liverpool. After excellent early schooling, Thomas was apprenticed for four years to his uncle, Dr. Owen Roberts, of St. Asaph, Wales.