Immediate effects of two modes of shortwave diathermy in chronic low back pain: randomized controlled clinical trial.

Aim: evaluate the immediate results of short-wave diathermy (SWD) in individuals with chronic low back pain (CLBP).

Materials and methods: individuals with CLBP, aged between 18 and 80, of both sexes, were selected for a double-blind, 3-arm, randomized, and controlled trial. The outcomes assessed were: pain by Numeric Rating Scale for pain (NRS), McGill Pain Questionnaire (MPQ), and Pressure Pain Threshold (PPT); disability; strength and power of lower limbs and flexibility of spine and lower limbs. The participants were randomized into three groups: continuous SWD (cSWD, n = 50), pulsed SWD (pSWD, n = 50), and placebo group (PG, n = 50). All groups received a single application of SWD for 30 mins and underwent assessment at three stages: pre-intervention, post-intervention, and follow-up.

Results: we found a significant difference between cSWD and PG in NRS (p < 0.05). Only pSWD showed a significant intergroup difference with PG in sensory and total MPQ index (p < 0.05). There were improvements in intra-group disability in pSWD and PG, in flexibility only in cSWD, and the power of lower limb post-intervention only in pSWD.

Conclusions: SWD endowed an immediate analgesic effect in individuals with CLBP.

Clinical trial registration: The www.ensaiosclinicos.gov.br/rg/RBR-2k58f5h/ identifier is RBR- 2k58f5h.