Transcutaneous vs Percutaneous Electrical Stimulation of the Radial Nerve

Summary

This study aims to compare the effects of two types of electrical nerve stimulation techniques-Transcutaneous Electrical Nerve Stimulation (TENS) and Percutaneous Electrical Nerve Stimulation (PENS)-on the sensory and motor components of the radial nerve in healthy volunteers.

Transcutaneous Electrical Nerve Stimulation (TENS) is a non-invasive, low-cost, and widely used electrotherapy technique that applies electrical currents through surface electrodes on the skin to relieve pain. Percutaneous Electrical Nerve Stimulation (PENS) is a minimally invasive technique that delivers the electrical current through fine needles inserted near a peripheral nerve, potentially producing stronger physiological effects.

In this randomized, double-blind controlled clinical trial, 120 healthy participants aged 18-60 years will be randomly assigned to one of four groups:

Transcutaneous Electrical Nerve Stimulation (TENS)

Percutaneous Electrical Nerve Stimulation (PENS)

Sham Transcutaneous Electrical Nerve Stimulation (TENS) (placebo)

Sham Percutaneous Electrical Nerve Stimulation (placebo)

Each participant will receive one 20-minute stimulation session. Outcomes will include:

Pressure pain threshold (PPT) (measured with an algometer),

Thermal pain threshold (measured with a thermode),

Maximal Isometric wrist extensor strength (measured with a hand-held dynamometer).

The goal is to determine whether Percutaneous Electrical Nerve Stimulation (PENS) produces greater changes in sensory and motor parameters than Transcutaneous Electrical Nerve Stimulation (TENS) and to evaluate differences compared to placebo. This research will improve understanding of the physiological effects of these commonly used electrotherapy modalities and support evidence-based decision-making in clinical practice.

Conditions

• Pain Modulation
• Sensorimotor Function
• Nerve Stimulation

Interventions

DEVICE

Transcutaneous Electrical Nerve Stimulation (TENS)

Participants will receive one 20-minute session of Transcutaneous Electrical Nerve Stimulation (TENS) applied over the radial nerve of the non-dominant forearm. Two surface electrodes will be placed under ultrasound guidance (General Electric (GE) Logiq P9), longitudinally along the nerve path, approximately 5-8 centimeters (cm) proximal and distal to the lateral epicondyle. Stimulation parameters will consist of a biphasic symmetrical current at 2 Hertz (Hz) frequency, 250 microseconds (µs) pulse width, and an intensity adjusted to the maximum tolerable level without pain. The stimulator used will be an ENRAF NONIUS Endomed 484 (Madrid, Spain). Participants will remain in a supine position with the forearm supported in a prone posture. In addition, participants will receive a placebo needle intervention, consisting of a non-penetrating sham needle applied to the same anatomical region without skin insertion. This procedure mimics the sensation of needling but does not break the skin o

DEVICE

Percutaneous Electrical Nerve Stimulation (PENS)

Participants will receive one 20-minute session of Percutaneous Electrical Nerve Stimulation (PENS) targeting the radial nerve of the non-dominant forearm. A sterile 0.30 × 50 millimeter (mm) acupuncture needle will be inserted under ultrasound guidance (General Electric (GE) Logiq P9, General Electric Healthcare, Milwaukee, WI, USA) approximately 1-2 mm from the radial nerve, at a depth of 2-3 centimeters (cm), avoiding direct contact. A surface electrode will be placed 2.5 cm distal and 1 cm cranial to the needle. Stimulation parameters: biphasic current, 2 Hertz (Hz) frequency, 250 microseconds (µs) pulse width, and intensity adjusted to the maximum tolerable level without pain. The stimulator used will be an ENRAF NONIUS Endomed 484 (Madrid, Spain). Participants will remain in a supine position with the forearm supported in a prone posture.

DEVICE

Sham Transcutaneous Electrical Nerve Stimulation

Participants will undergo a sham Transcutaneous Electrical Nerve Stimulation (TENS) procedure identical in setup and duration to the active TENS group. Two surface electrodes will be placed under ultrasound guidance (General Electric (GE) Logiq P9) along the nerve path, 5-8 cm proximal and distal, and the current will be increased for \~30 seconds until a strong but comfortable tingling is felt, then reduced to 0 milliamperes (mA). The electrodes will remain in place for 20 minutes to mimic the active procedure. The stimulator (ENRAF NONIUS Endomed 484) will remain on but deliver no current. Neither participants nor evaluators will have visual access to the device display to maintain blinding. Participants will also receive a placebo needle intervention, consisting of a non-penetrating sham needle applied to the same anatomical region without skin insertion. This procedure mimics the sensation of needling but does not break the skin or produce physiological effects.

DEVICE

Sham Percutaneous Electrical Nerve Stimulation

Participants will undergo a sham Percutaneous Electrical Nerve Stimulation (PENS) procedure identical in setup and duration to the active PENS group. A sterile needle (0.30 × 50 millimeters (mm)) will be inserted under ultrasound guidance (General Electric (GE) Logiq P9, General Electric Healthcare, Milwaukee, WI, USA) at the same anatomical site and depth as in the active PENS group. However, no electrical current will be applied. The stimulator (ENRAF NONIUS Endomed 484) will remain on but disconnected from the needle to maintain participant blinding. Neither participants nor evaluators will have visual access to the device screen. Total session duration: 20 minutes.

Sponsors & Collaborators

• University of Castilla-La Mancha

  lead OTHER

Principal Investigators

• Diego Serrano Muñoz, Universidad de Castilla-La Man · Universidad de Castilla-La Mancha, Faculty of Physiotherapy and Nursing, Toledo, Spain

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

60 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2026-01-15

Primary Completion

2026-03-15

Completion

2026-04-15

Countries

• Spain

Study Locations