A method, apparatus, computer program product and system are provided to determine the position of at least a portion of the body of a subject, thereby providing for motion estimation and/or body posture detection. In regards to a method, information is received regarding a signal that propagated through a capacitively-coupled intra body communication channel in a body from a first node to a second node. The method also evaluates the information regarding the signal in order to determine information regarding a position of at least a portion of the body. By evaluating the information, the method identifies different positions of at least the portion of the body based upon the signal that propagated through the capacitively-coupled intra body communication channel that varies in a manner attributable to changes in capacitance between the first and second nodes.
