This monograph is the result of work carried out between October 2007 and October 2010 at the Center for Sensory-Motor Interaction, Aalborg University (Denmark), supported by The Danish Research Council for Technology and Production Sciences (FTP). Five months of this period, between September 2009 and February 2010, were carried out at the University Hospital of Bern, Inselspital (Switzerland) as part of an ongoing collaboration between these two institutions. This stay abroad was supported through an EliteForsk travel stipend, granted by the Danish Ministry of Science, Technology and Innovation.This book is a contribution to the understanding of the mechanisms underlying central sensitization of spinal nociception in humans. The aims of this project were to explore different models of central sensitization in humans and to assess them objectively using nociceptive withdrawal reflexes and reflex receptive fields.The book contains four chapters. The first chapter presents the necessary background knowledge on central sensitization, the aim of the project and an overview of the dissertation. The second chapter depicts the methodology used for objective assessment of central sensitization, using nociceptive withdrawal reflexes and reflex receptive fields. The third chapter describes the human models for central sensitization studied during this project, and the thesis is completed with a fourth chapter with a brief conclusion and future perspectives.