Body Biasing Injection (BBI), compared to other injection techniques, is quite recent. It consists in applying a voltage pulse onto the backside surface of an integrated circuit with a needle. Despite its simplicity, and probably because of its recentness, there is very little knowledge on how faults occur, nor as on the characteristics of this injection technique. Within this context, this paper provides insights about the interest of thinning the substrate of ICs in order to enhance the efficiency of BBI as well as its spatial resolution. Those insights were obtained both by experiment and simulation. As a result, elements for simulating the propagation of a perturbation are provided.