Designers and engineers have been dreaming for decades with motors sensing, by themselves, working and surrounding conditions, as biological muscles do originating proprioception. The evolution of the working potential, or that of the consumed electrical energy, of electrochemical artificial muscles based on electroactive materials (intrinsically conducting polymers, redox polymers, carbon nanotubes, fullerene derivatives, grapheme derivatives, porphyrines, phtalocyanines, among others) and driven by constant currents senses, while working, any variation of the mechanical (trailed mass, obstacles, pressure, strain or stress) thermal or chemical conditions. They are linear faradaic polymeric motors: applied currents control movement rates and applied charges control displacements. One physically uniform artificial muscle includes one motor and several sensors working simultaneously under the same driving chemical reaction. Actuating (current and charge) and sensing (potential and energy) magnitudes are present, simultaneously, in the only two connecting wires and can be read by the computer at any time. From basic polymeric, mechanical and electrochemical principles a basic equation is attained for the muscle working potential evolution. It includes and describes, simultaneously, the polymeric motor characteristics (rate of the muscle movement and muscle position) and the working variables (temperature, electrolyte concentration and mechanical conditions). By changing working conditions experimental results overlap theoretical predictions. The ensemble computer-generator-muscle-theoretical equation constitutes and describes artificial mechanical, thermal and chemical proprioception of the system. Proprioceptive tools, zoomorphic or anthropomorphic soft robots can be envisaged.