Immediate analgesic effect of two modes of short-wave diathermy application in chronic low back pain: study protocol for a randomized controlled trial.

Lay abstract Aim : Low back pain is one of the main health problems in the world. Short-wave diathermy (SWD) is a physiotherapy device that can be used to treat low back pain, but its scientific effectiveness is uncertain. Objective: To evaluate and compare the effects of pain reduction immediately after application of the device (SWD) in two different application methods in individuals with chronic low back pain. Materials & methods: Clinical trial in which 159 individuals will be selected and randomly allocated into three groups: pulsed short-wave diathermy group, n = 53; continuous short-wave diathermy group, n = 53 and placebo group, n = 53. The technique will only be applied once for 30 min. The main result analyzed will be pain. Other results that will also be evaluated are perception of global improvement and treatment satisfaction, functionality (ability to perform daily tasks), leg strength and trunk mobility. It will also be verified the presence of depression, anxiety, psychological and social factors that may influence the response to treatment. Individuals will be evaluated before the first session, immediately after the application of the device and 1 week later. Conclusion: It is expected to verify the decrease in pain soon after the application of the device in the chronic low back pain and find out if there is any difference in this outcome according to the application method.