Impact of Different Electrical Frequencies Used in Percutaneous Neuromodulation on Muscle Strength and Pressure Pain Thresholds

NCT ID: NCT07269925

Last Updated: 2025-12-15

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 30 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-02-15
• Study Completion Date: 2026-07-30

Brief Summary

Percutaneous electrical nerve stimulation (PENS) involves delivering electrical currents through fine filiform needles inserted near tissues such as muscles, ligaments, or nerves. It has been explored for various chronic pain conditions affecting the cervical and lumbar spine, as well as the upper and lower limbs. Despite its growing clinical use, the overall quality of evidence supporting PENS for chronic musculoskeletal pain remains limited. Most studies have applied the technique directly over nerve structures, and while some reviews have shown greater pain reduction compared to transcutaneous electrical nerve stimulation (TENS), the superiority of PENS has not been conclusively demonstrated. Research specifically examining its application on nerve tissues, particularly in the upper limbs, remains scarce. Some preliminary and single-case studies have reported improvements in pain and disability following PENS directed at the radial nerve, but these findings are limited by small sample sizes and the absence of control groups. The physiological mechanisms underlying PENS are still not fully understood, though both peripheral and central processes are believed to be involved. Evidence suggests that PENS can reduce local sensitivity to pressure pain through peripheral mechanisms and may also enhance descending inhibitory control by activating conditioned pain modulation at the central level. However, further studies are necessary to clarify these effects.

Since to date, limited research has specifically examined the optimal PENS dosage, the present study aimed to compare two PENS dosage for improving muscle strength and pain pressure thresholds.

Conditions

Shoulder Pain

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Low Frequency PENS

Participants will receive a single session of PENS setting 2 Hz frequency, 250 µs pulse width, 10 minutes duration, with an intensity (mA) sufficient to elicit a visible motor response while remaining comfortable for the patient.

Group Type: EXPERIMENTAL

Percutaneous electrical nerve stimulation: Low frequency

Intervention Type: OTHER

A single PENS session will be applied under ultrasound guidance using sterile, single-use filiform needles placed in the suprascapular and axillary nerves and connected to an electrostimulator APSe4 (Agupunt, Barcelona). Dosage will be: 2 Hz frequency, 250 µs pulse width, 10 minutes duration, with an intensity (mA) sufficient to elicit a visible motor response while remaining comfortable for the patient.

High Frequency PENS

Participants will receive a single session of PENS setting 100 Hz frequency, 250 µs pulse width, 5-second stimulation followed by 55-second rest, with an intensity (mA) sufficient to elicit a visible motor response while remaining comfortable for the patient and repeated five times.

Group Type: EXPERIMENTAL

Percutaneous electrical nerve stimulation: High frequency

Intervention Type: OTHER

A single PENS session will be applied under ultrasound guidance using sterile, single-use filiform needles placed in the suprascapular and axillary nerves and connected to an electrostimulator APSe4 (Agupunt, Barcelona).

Dosage will be: 100 Hz frequency, 250 µs pulse width, 5-second stimulation followed by 55-second rest, repeated five times

Interventions

Percutaneous electrical nerve stimulation: High frequency

A single PENS session will be applied under ultrasound guidance using sterile, single-use filiform needles placed in the suprascapular and axillary nerves and connected to an electrostimulator APSe4 (Agupunt, Barcelona).

Dosage will be: 100 Hz frequency, 250 µs pulse width, 5-second stimulation followed by 55-second rest, repeated five times

Intervention Type: OTHER

Percutaneous electrical nerve stimulation: Low frequency

A single PENS session will be applied under ultrasound guidance using sterile, single-use filiform needles placed in the suprascapular and axillary nerves and connected to an electrostimulator APSe4 (Agupunt, Barcelona). Dosage will be: 2 Hz frequency, 250 µs pulse width, 10 minutes duration, with an intensity (mA) sufficient to elicit a visible motor response while remaining comfortable for the patient.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• Presence of at least one latent myofascial trigger point (MTrP) in the infraspinatus muscle, identified according to the most recent Delphi consensus criteria.
• Ability to read, understand, and sign the written informed consent form.

Exclusion Criteria

• Current pharmacological treatment that may affect muscle tone.
• History of shoulder or spinal surgery.
• Traumatic disorders such as whiplash-associated injuries, dislocations, or fractures.
• Neuropathies, including radiculopathies or myelopathies.
• Severe medical conditions (e.g., tumors, fractures, neurological or systemic diseases).
• Clinically relevant asymmetries.
• Generalized musculoskeletal conditions such as fibromyalgia.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Universidad Rey Juan Carlos

OTHER

Sponsor Role: collaborator

Universidad Complutense de Madrid

OTHER

Sponsor Role: lead

Responsible Party

JUAN ANTONIO VALERA CALERO

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

ATMIS

Krakow, Poland, Poland

Countries

Poland

Central Contacts

Juan Antonio Valera-Calero, PhD

Role: CONTACT

juavaler@ucm.es

0034 653 766 841

Facility Contacts

Juan Antonio Valera-Calero

Role: primary

juavaler@ucm.es

0034 653 766 841

Other Identifiers

UComplutenseMadrid-PENS

Identifier Type: -

Identifier Source: org_study_id