Medical body area networks (MBANs) operating in the 2360–2390 MHz band enable continuous health monitoring across a wide range of clinical and home-care applications. This paper presents a comprehensive performance evaluation of off-body MBAN links based on Monte Carlo simulations using empirically derived channel models from the IEEE 802.15.6 standard. Two transmitter locations, chest mounted and right wrist mounted sensors, are investigated under standing and walking conditions for distances ranging from 1 m to 4 m and angular orientations of 0°, 90°, 180°, and 270°. The impact of sensor placement and gait dynamics on bit error rate (BER) and theoretical maximum achievable throughput is analyzed. Constraints and practical hardware limitations are considered by restricting transmit power to specific absorption rate (SAR) and by analyzing energy consumption using parameters from commercial wearable transceivers. The obtained Eb/N0 values range from 10 dB to 76 dB at n=2, while throughput varies between 68.5 bps and 270 Mbps depending on distance, activity, and orientation. High Eb/N0 values observed under severe fading conditions are shown to be impractical under realistic power and energy constraints. The results indicate that transmission distance is the dominant performance factor in static scenarios, whereas sensor placement becomes more important under dynamic conditions. In general, chest mounted sensors outperform wrist mounted sensors due to reduced body shadowing in the first case. Furthermore, the use of equal gain combining (EGC) is shown to overcome mobility induced performance degradation for chest mounted nodes, enabling reliable support of a 1 Mbps data rate in all considered scenarios considering the chest as the Tx. Robustness analysis under obstructed indoor propagation (n = 3.5) confirms that although absolute throughput decreases with higher path loss, the relative performance ranking between placement and mobility scenarios remains unchanged. These findings provide quantitative design guidance for reliable and energy efficient MBAN deployment in indoor healthcare environments.