Efficacy of Sciatic Nerve Electrical Stimulation and Therapeutic Exercise in the Management of Low-back Related Leg Pain
Universidad Complutense de Madrid
88 participants
May 13, 2026
INTERVENTIONAL
Conditions
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 efficacy and safety 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, in combination with a therapeutic exercise program. 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. We 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. In addition to these treatments, all participants will take part in a structured exercise program aimed at strengthening the lower back, pelvis, and legs. Exercises like curl-ups, planks, bridges, bird-dogs, and squats will be supervised weekly for six weeks, with guidance to continue practicing at home. Exercise is included because it is known to help improve mobility, strength, and recovery in people with back problems. 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. We 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; and patients' global impression of improvement and any side effects. Assessments will take place before starting the treatment, at the end of the 6-week program, and then again at 3 and 6 months. This allows us to see both the short-, mid- and long-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 PENS in combination with therapeutic exercise 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.
Eligibility
Inclusion Criteria8
- Neuropathic-like LBRLP (sciatica).
- S-LANSS score ≥ 12 points.
- LBRLP lasting more than 6 months.
- Age between 18 and 70 years.
- LBRLP in the past 4 weeks has been severe enough to limit usual activities or change daily routines for more than 1 day.
- At least one period of 6 months to 1 year during which the participant did not go a full month without LBRLP.
- LBRLP intensity of at least 3/10 on the NPRS.
- Ability to provide informed consent.
Exclusion Criteria8
- Acute injury or recent major trauma history.
- Relevant painful conditions of the hip joint or pelvic/sacroiliac region.
- Symptoms compatible with cauda equina syndrome (loss of bladder/bowel control, sexual dysfunction, paralysis of lower limbs, etc.).
- Previous surgery on the spine, pelvis or hip.
- Prior treatment with anesthetic or anti-inflammatory blocks or with radiofrequency (facet, sacroiliac, radicular, epidural, etc.) in the past two years.
- Any neurological or systemic disease that could limit participation in the study.
- Inability to communicate in Spanish or understand study instructions and content.
- General contraindications for invasive physiotherapy and electrotherapy techniques.
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Interventions
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.
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.
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.
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.
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.
The program will include five lumbopelvic strengthening and stabilization exercises plus a squat exercise. Each participant will attend one supervised weekly session led by a physiotherapist and will be encouraged to repeat the program at home at least twice a week. Progression will depend on pain tolerance and perceived exertion. Each session will include warm-up (5-7 min), strengthening (20-25min) and cool-down (5 min). Before starting with the main exercises, participants will do a warm-up designed to improve general and specific mobility of the lumbar spine and lower limbs, including five exercises (1 minute each). Then, strengthening exercises will be performed, including Curl-up, Bird-Dog, Side plank, Front plank, Glute bridge and Controlled partial squat. Finally, a brief cool-down period will be carried out, focused on active mobility and gentle stretching to facilitate recovery and reduce potential muscle overload, consisting of four exercises (1 minute each).
Locations(1)
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NCT07373808