Resumo do estudo

Twenty patients with low back pain or a history of low back pain were randomized in a crossover design to receive capacitive and resistive monopolar radiofrequency (CRMF), hotpack, or sham treatment in random order. The outcomes of interest were the shear elastic modulus of the multifidus and erector spinae muscles measured by ultrasound elastography and measurements in different positions (rest and stretched) at multiple time points. Outcomes were assessed before, immediately after, and 30 minutes after each intervention. Overall, the results of the study revealed that CRMF significantly reduced the multifidus muscle stiffness in the stretched position immediately after treatment, but this effect was not sustained at 30 minutes. These findings suggest that high-frequency hyperthermia provides short-term reductions in lumbar muscle stiffness but lacks lasting effects.