Electrical therapy is used extensively in the treatment of musculoskeletal diseases. The best known form is transcutaneous electrical nerve stimulation (TENS). Rebox is another apparatus for electrical therapy that operates on much lower currents than TENS (0 to 300 microA). The effect of Rebox was tested on chronic lateral epicondylitis in 16 patients in a controlled crossover study. We found a significant effect of Rebox compared to placebo in respect to all the subjective and the objective variables: grip-strength, pain at power-grip and lifting a weightload with pronated forearm, and daily impairment.