This paper presents the medical body area networks (MBAN) are seen as a key challenge for the wireless communications community (e.g., IEEE 802.15.6) who are focusing on a range of issues including security, power consumption, reliability, capacity, range error performance. Interestingly, in MBANs the antennas and propagation aspects of the problem can be shown to have a significant effect on all of these important issues. Therefore, in this paper we will present some of our current antennas and propagation research results and how they may be applied to improve the performance of MBANs. One of the most important considerations for MBAN applications is the ability to efficiently couple two low-profile, compact nodes that do not have line-of-sight. Nonetheless, even at relatively low frequencies (such as the 868 MHz ISM band), it is also possible to improve the performance of on-body communications using simple two-branch diversity.