Strong relationships have being established between TENS (Transcutaneous Electrical Nerve Stimulation) and pain relief for both acute and chronic pain conditions. TENS activates opioid receptors along the neural pathways in the brain and spinal cord. Increases pain thresholds have been demonstrated in healthy human subjects when using Pressure Pan Threshold as an outcome measure. With this relation established, we investigated if it made difference where we placed the electrodes for a 30 minute treatment to the right forearm. Preliminary data using the Checktrode impedance meter (UFI, Morro Bay, CA) showed that certain sites on the arm have lower impedance as compared to others. Our hypothesis is that applying TENS over sites with lower impedance will allow for greater depolarization of sensory nerve fibers and greater activation of opioid receptors. We labeled low impedance sites as optimal (OSS) and high impedance sites as sham (SSS). Healthy subjects from 18 to 60 years of age were recruited to participate in 3 separate TENS treatment sessions. Each subject received the following treatments in a random order: 1) Active TENS and OSS, 2) Sham TENS and OSS and 3) Active TENS and SSS. PPT measurement were taken with the Somedic Algometer (Somedic, Horby, Sweden) before, during and after a 30 minute TENS treatment."