Current intensity depends on the patient’s tolerance (usually the maximum intensity tolerable), and it could range in a scale between 10 and 100 mA. The pulse shape afterward can be variable between rectangular, quadratic (square), symmetric, or asymmetric. Duration of stimulus (measured in ms) varied between 0.2 and 1 ms. The proper value depends on the statement that a long-term impulse (≥1 ms) electively stimulates sensory fibers, while an impulse ≤0.2 ms stimulates the motor fibers. The stimulation time (also described as “duty cycle” or “work time”) was commonly set in 1:2 ratio, and commonly the rest time is double the stimulation time. However, the most important stimulation parameter of FES (EStim) remains the frequency, which could be defined as the cycle number or electrical phases per second and is expressed in hertz (Hz). A common adopted criterion in urologic rehabilitative trials provides a range of frequencies varying from 20 to 50 Hz for application in stress urinary incontinence treatment, while lowest frequencies (5–20 Hz) have been adopted for the treatment of urge urinary incontinence or overactive bladder syndrome and detrusor overactivity. The physiologic basis of the different values depends on physical property of the neural fibers. In fact tonic fibers (less diameter) discharge at a frequency of 10–20 Hz, while phasic fibers (greater diameter) discharge at a frequency of 30–60 Hz. Some authors suggested an alternation of frequencies into the same program in order to reproduce a natural succession of motor neuron discharge [16]. In Table 7.1 we summarized indications and contraindication to functional electrical stimulation, while in Tables 7.2 and 7.3, we resumed some of the EStim programs reported by the most recent literature revision as benchmarks [22].

In the following schedule the operative methodology adopted in our clinical practice for each FES/EStim application is reported.