If you are found to be eligible to take part in this study, you will be randomly assigned (as in the toss of a coin) to be in 1 of 2 groups. Participants in one group will receive electro-stimulation at an active (responsive) acupuncture site on the bottom of the foot. Participants in the other group will receive electro-stimulation at a inactive site on the bottom of the foot (a "placebo" site).