Optimal Low-Frequency Parameter of Percutaneous Electrical Nerve Stimulation in Patients with Lower Back Pain: A Pilot Study.

Background

The methodology of ultrasound (US)-guided percutaneous neuromodulation (PNM) remains unclear.

Objective

To determine the optimal stimulation frequency (3 Hz vs. 10 Hz) during the short-term application of US-guided PNM on the sciatic nerve, we assessed the therapeutic benefits, including pain reduction, hip passive internal rotation range of motion (IR-ROM), balance, and functionality, in patients with chronic low back pain (LBP).

Methods

Forty patients with LBP were randomly assigned to two groups, each receiving isolated percutaneous electrical stimulation of the sciatic nerve. One group received stimulation at 3 Hz, while the other received stimulation at 10 Hz. Pain intensity, hip passive IR-ROM, hip muscle strength, and the Oswestry Disability Index (ODI) were measured before and one week after the intervention.

Results

Both interventions significantly reduced pain and improved ROM, balance, and functionality after one week (p = 0.001). However, significant between-group (treatment × time) differences were observed for pain intensity (p = 0.001) and flexion strength in the non-intervention limb (p = 0.01), though the effect size was small (η2 = 0.1).

Conclusions

US-guided PNM applied to the sciatic nerve was more effective at 3 Hz than at 10 Hz in relieving pain intensity in patients with LBP.