A system for restoring muscle function to the lumbar spine, the system comprising: one or more electrodes (200, 202, 204, 206, 208, 210) configured to be implanted in or adjacent to tissue associated with control of the lumbar spine; an implantable pulse generator (300, 300', 300") coupled to the one or more electrodes, the implantable pulse generator having a programmable controller (318, 318', 318") configured to run a routine to measure impedance of the one or more electrodes and a first communications circuit (320, 320", 322, 322", 332, 332", 334, 334"), the implantable pulse generator storing a unique device identifier assigned to that implantable pulse generator and an encryption routine; a handheld activator (400, 400') having a second communications circuit (428, 430, 438, 440), the activator configured to transfer an encrypted stimulation command to the implantable pulse generator via the first and second communications circuits, the encrypted stimulation command including the unique device identifier assigned to the implantable pulse generator; an external programmer (500, 500') having a third communications circuit (518, 520, 528, 530), the external programmer configured to transfer programming data to the implantable pulse generator via the first and third communications circuits, the programming data including the unique identifier assigned to the implantable pulse generator; and software configured to run on a computer coupled to the external programmer, the software configured to send a command, via the external programmer, to the implantable pulse generator to run the routine and then transmit the measured impedances back to the computer via the external programmer, wherein the software is further configured to display the measured impedances for each of the one or more electrodes, wherein the encrypted stimulation command from the handheld activator directs the programmable controller to stimulate the tissue in accordance with the programming data transferred to the implantable pulse generator by the external programmer. one or more electrodes (200, 202, 204, 206, 208, 210) configured to be implanted in or adjacent to tissue associated with control of the lumbar spine; an implantable pulse generator (300, 300', 300") coupled to the one or more electrodes, the implantable pulse generator having a programmable controller (318, 318', 318") configured to run a routine to measure impedance of the one or more electrodes and a first communications circuit (320, 320", 322, 322", 332, 332", 334, 334"), the implantable pulse generator storing a unique device identifier assigned to that implantable pulse generator and an encryption routine; a handheld activator (400, 400') having a second communications circuit (428, 430, 438, 440), the activator configured to transfer an encrypted stimulation command to the implantable pulse generator via the first and second communications circuits, the encrypted stimulation command including the unique device identifier assigned to the implantable pulse generator; an external programmer (500, 500') having a third communications circuit (518, 520, 528, 530), the external programmer configured to transfer programming data to the implantable pulse generator via the first and third communications circuits, the programming data including the unique identifier assigned to the implantable pulse generator; and software configured to run on a computer coupled to the external programmer, the software configured to send a command, via the external programmer, to the implantable pulse generator to run the routine and then transmit the measured impedances back to the computer via the external programmer, wherein the software is further configured to display the measured impedances for each of the one or more electrodes, wherein the encrypted stimulation command from the handheld activator directs the programmable controller to stimulate the tissue in accordance with the programming data transferred to the implantable pulse generator by the external programmer.