The rapid advances in sensors and ultra-low power wireless communication has enabled a new generation of wireless sensor networks: Wireless Body Area Networks (WBAN). WBAN is a recent challenging area in the health monitoring domain. There are several concerns in this area ranging from energy efficient communication to designing delays efficient protocols that support nodes dynamic induced by human body mobility. WBAN is a promising technology and shall be increasingly necessary for monitoring, diagnosing and treating populations.In this work we are interested in WBAN where sensors are placed on the body. In this type of networks sensors performances are tremendously influenced by the human body mobility. Thus, we investigate different communication primitives using a realistic human body mobility and channel models issued from a recent research on biomedical and health informatics.