It substitutes for prolonged hand maneuvering. This helps assure that the patient gets the amount of stimulation needed, because the practitioner may otherwise pause due to fatigue. Electro-acupuncture may also help reduce total treatment time by providing the continued stimulus. During electro-acupuncture, the practitioner can attend to other patients.
It can produce a stronger stimulation, if desired, without causing tissue damage associated with twirling and lifting and thrusting the needle. Strong stimulation may be needed for difficult cases of neuralgia or paralysis.
It is easier to control the frequency of the stimulus and the amount of stimulus than with hand manipulation of the needles.