The effects of TENS, interferential stimulation, and combined interferential stimulation and pulsed ultrasound on patients with disc herniation-induced radicular pain

BACKGROUND: Electrotherapy is part of a physician's toolbox for treating various musculoskeletal conditions, including radicular pain, but the preferred modality is yet unclear. OBJECTIVE: To compare the short-term efficacy of three electrotherapeutic modalities in relieving lumbar disc herniation (LDH)-induced radicular pain. METHODS: Fourteen patients with LDH-induced radicular pain attended a single session of electrotherapy, which included four 10-min consecutive treatments: transcutaneous electrical nerve stimulation (TENS), interferential (IF) stimulation, a combined treatment with pulsed ultrasound and IF current (CTPI), and a sham control. Treatments were randomized and the straight leg raise (SLR) degree was measured immediately before and after each treatment. RESULTS: Each of the three active modalities significantly improved the SLR score. The most prominent improvement was observed in the CTPI condition, followed by IF and, finally, TENS. The sham stimulation did not affect the SLR scores. CONCLUSIONS: A single session with either TENS, IF current or CTPI is sufficient to improve the range of motion and degree of radicular pain associated with LDH. CTPI appears to be the most effective modality of the three, possibly due to greater penetration efficiency of the induced current. The effects of a long-term treatment schedule are yet to be identified.