Overcoming Analgesic Tolerance to TENS

Transcutaneous electrical nerve stimulation (TENS) is utilized clinically by a variety of health care professionals for the reduction of pain. The mechanisms by which TENS produces analgesia or reduces pain are only recently being elucidated. TENS is a non-invasive modality that is inexpensive, safe and easy to use with relatively few contraindications. Frequency of stimulation is broadly classified as high frequency (\>50Hz), low frequency (\<10Hz) TENS. Intensity is determined by the response of the patient as either sensory level (low-intensity) TENS strong but comfortable. With sensory level TENS, the voltage (i.e. amplitude) is increased only until the patient feels a comfortable tingling (perceived with high frequency) or tapping (perceived with low frequency) sensation without motor contraction. With strong but comfortable TENS the intensity is increased to a strong but comfortable level which may include muscle contraction.