Lateral epicondylitis is a challenging condition to treat. Non-operative modalities are not always successful, and the condition can persist for months without relief. Many different modalities have been tested to treat lateral epicondylitis. In this study, the authors compared shortwave diathermy to sham diathermy to assess the impact of this electromagnetic modality on patient pain, function, and grip strength. After randomizing 50 patients to real or sham diathermy, and applying the therapy every other day for ten sessions, the authors found a significantly greater improvement in pain and grip strength in the diathermy group. There was no difference in functional scores.