There is disclosed a device and method for delivering constant target current to a muscle for electro-stimulation of that muscle. One device is a completely self-contained device with no external means for the adjustment and control of the electro-stimulation delivered to the muscle during treatment. The microprocessor based device monitors indirectly the actual current delivered to the muscle during electro-stimulation via measurement of the return path voltage through the muscle and optionally in addition monitors and adjusts for the internal battery voltage during use of the device in order to deliver a more consistent an accurate and effective target output current to the muscle being stimulated at each and every pulse delivered from the device. The device is pre-programmed with an electro-stimulation treatment cycle and the whole treatment cycle, including the monitoring and adjustment required to achieve this treatment cycle, is automatic within the device.
