Immediate and 1-week Efficacy of a Single Session of Sciatic Nerve Electrical Stimulation in the Management of Low-back Related Leg Pain

Summary

This clinical study focuses on people who experience long-term low-back related leg pain (commonly called sciatica). This type of pain is often associated with nerve irritation or compression in the lower spine and can cause symptoms like shooting or burning pain, tingling, numbness, or weakness in the leg. Many patients continue to suffer from this problem for months or years, and available treatments (including painkillers, anti-inflammatory drugs, or even surgery) do not always provide lasting relief. Because of this, there is a strong need to explore safe, non-drug, non-surgical therapies. The purpose of this study is to test the immediate and short-term efficacy and safety of a single session of a treatment called Percutaneous Electrical Nerve Stimulation (PENS) when applied near the sciatic nerve, the large nerve that runs from the lower back through the buttock and down the leg. PENS uses very thin sterile needles inserted under ultrasound guidance next to the nerve. A gentle electrical current is then applied for about 30 minutes to stimulate the nerve in a controlled way. This may help calm down nerve sensitivity, reduce inflammation, and decrease pain. The investigators will compare PENS with three other options: Transcutaneous Electrical Nerve Stimulation (TENS): A commonly used therapy where mild electrical stimulation is applied through adhesive patches placed on the skin; Dry needling without electrical current: Thin needles are inserted under ultrasound guidance but no current is applied; and placebo treatment: A simulated version of the therapy with no active current, designed to look and feel similar so that participants do not know which treatment they are receiving. The study is designed as a randomized, controlled, double-blind trial, which means that participants are assigned to one of the four groups by chance (like flipping a coin), and neither the patients nor the therapists who collect the measurements will know which treatment has been given. This design ensures fairness and reliability of the results. The investigators will measure: Back and leg pain levels, using a simple 0-10 scale; Disability, meaning how much the pain limits daily activities, measured with a well-known questionnaire; Quality of life, both physical and mental health aspects; Nerve-related pain features, like burning or electric-like sensations; Flexibility and movement, through the Straight Leg Raise test; Sensitivity to pressure and nerve stiffness, using ultrasound elastography, which is a safe imaging technique; and patients' global impression of improvement and any side effects. Assessments will take place before and immediately after the treatment session and after 1 week, allowing the investigators to see both the immediate and short-term effects. Safety considerations: Previous research shows that PENS and similar techniques are generally very safe. The most common side effects are mild and short-lasting, including temporary soreness, heaviness in the leg, or a small bruise. Serious complications are extremely rare. To minimize risks, all procedures will be carried out by experienced physiotherapists, using real-time ultrasound to guide needle placement and ensure accuracy. Only sterile, single-use needles are employed. By comparing PENS, TENS, dry needling, and placebo, this study seeks to determine whether a single session of PENS provides superior benefits in reducing pain, improving function, and enhancing quality of life for patients with sciatica-type low back pain. If successful, this treatment could become a valuable alternative to drugs or surgery, offering patients a safe and effective therapy to better manage their condition and regain daily function.

Conditions

• Sciatica

Interventions

PROCEDURE

Percutaneous Electrical Nerve Stimulation

Participants will receive real ultrasound-guided dry needle insertion (0.30 mm × 60 mm and 0.30 mm ×50 mm) to the perineural region adjacent to the sciatic nerve at both the subgluteal fold and the posterior thigh (junction between the middle and distal thirds). Electrical stimulation will be applied using the Endomed 484® electrotherapy unit (PRIM Physio, Madrid, Spain) in continuous biphasic mode at low frequency (2 Hz), 250 μs pulse width for 30 minutes. Intensity will be adjusted to elicit a visible, mild muscle contraction.

PROCEDURE

Placebo Transcutaneous Electrical Nerve Stimulation

Adhesive electrodes will be placed near the intervention site (sciatic nerve between the subgluteal fold and the distal third of the thigh) but connected to a disabled channel to simulate placebo TENS.

PROCEDURE

Transcutaneous Electrical Nerve Stimulation

Participants will receive real superficial electrical stimulation via adhesive electrodes connected to the Endomed 484® unit, configured for TENS (non-invasive). Parameters will include continuous biphasic current, 2 Hz, 250 μs, 30 min, producing a clear sensory perception and mild muscle contraction.

PROCEDURE

Placebo Percutaneous Electrical Nerve Stimulation

A sham ultrasound-guided dry needling procedure will be performed using Streitberger placebo needles, which contact the skin superficially without penetration. Cables for PENS will be placed on the skin but connected to a disabled channel to simulate placebo PENS.

PROCEDURE

Real Dry Needling (without Percutaneous Electrical Nerve Stimulation)

Participants will receive real ultrasound-guided dry needling but without electrical stimulation. The needles will remain in place for 30 minutes, with the PENS channel disabled to act as placebo.

Sponsors & Collaborators

• Colegio de Fisioterapeutas de la Comunidad de Madrid

  collaborator OTHER

• Universidad Complutense de Madrid

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

70 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-05-13

Primary Completion

2026-12-31

Completion

2027-11-30

Countries

• Spain

Study Locations