The arched dorsal posture in obstetrics: the combined Trendelenburg-Walcher posture in obstetric operating, the Walcher, the Trendelenburg, and the Mercurio postures in midwifery

The arched dorsal posture in obstetrics: the combined Trendelenburg-Walcher posture in obstetric operating, the Walcher, the Trendelenburg, and the Mercurio postures in midwifery