Collaborative body sensor network (CBSN) is formed of several body sensor networks (BSNs) moving in a given area and able to exchange data between each other. One of the challenges in CBSN is to design a Medium Access Protocol that efficiently supports nodes mobility, and at the same time, guarantees immediate delivery of urgent data, and maintains high energy efficiency during regular observation. In this paper, a hybrid traffic and mobility aware MAC (TMA-MAC) is proposed to satisfy CBSN's traffic requirements through adopting a hybrid DS-CDMA/DTDMA technique, and to support CBSN's nodes mobility through ensuring efficient transmission of intracluster mobile nodes data and proposing a mechanism to handle inter-cluster nodes joining requests. TMA-MAC was compared to other existing protocols under both traffic and mobility variations. Simulations were conducted using OPNET to evaluate TMA-MAC with respect to packet delay, packet drop percentage, and energy consumption.