Pain relief at trigger points: a comparison of moist heat and shortwave diathermy

This study compared the pain-relieving effects of shortwave diathermy and moist heat on trigger points. Patients with trigger points on the neck or back were randomly assigned one of these treatments. The sensitivity of each trigger point was measured with a pressure algometer before treatment, 5 minutes after treatment, and 30 minutes after treatment. Sensitive trigger points, at which 2000 grams of force or less caused pain, were more responsive to treatment than moderate trigger points (painful only at 2000 grams or greater force). Both treatments were effective in relieving the pain of sensitive trigger points but shortwave diathermy was more effective at decreasing the sensitivity of both sensitive and moderate trigger points (P > 0.0581). The pressure algometer was shown to be a useful device for objectively measuring pain and may be useful in selecting the most effective type of treatment for trigger points.J Orthop Sports Phys Ther 1984;5(4):175-178.