High Frequency RF Current Effects on Muscle Pain and Function

April 16, 2026 updated by: Eleftherios Kellis, Aristotle University Of Thessaloniki

Acute and Chronic Effects of High Frequency RF Electrical Current on Pain and Muscle Function in Individuals With Musculoskeletal Pain

The purpose of this study is to examine the acute and chronic effects of high frequency electrical current transfer (frequently called "TECAR") on pain and functional movement in individuals with a musculoskeletal injury or pain. The participants will be assigned into an experimental or a control group and outcome measures will be measured prior to, after, 24 and 48 hours following a single intervention session (Acute effects) as well as 3 and 6 months after the intervention (chronic effects).

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The purpose of this study is to examine the acute and chronic effects of high-frequency electrical current transfer (TECAR) on pain and functional movement in individuals with musculoskeletal injuries. The project is conducted in two phases to distinguish between immediate and long-term therapeutic outcomes. In the first phase, the acute effects of a single 20-minute TECAR session (Capacitive mode, 0.5 MHz, 40-60% intensity) are compared to transcutaneous electrical stimulation (TENS, asymmetric biphasic mode, 80Hz) and a control group in participants with acute hamstring strain or acute low back pain, defined as episodes occurring for less than half the days in the past six months with a visual analogue pain intensity > 6/10. Outcome measures are obtained at baseline, immediately post-intervention, and at 24 and 48 hours. In the chronic phase, participants with hamstring injuries or chronic low back pain receive 10 sessions (3 times per week) while outcome measurements are obtained before, immediately after, and at 3 and 6 months follow-up. Statistical analysis involves a Mixed-Model Analysis of Variance (ANOVA) to evaluate group-by-time interactions for outcomes including the Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and flexibility measures. For significant results, Tukey's post-hoc tests are utilized for pairwise comparisons. Additionally, non-parametric Kruskal-Wallis and Friedman tests are used to analyze percentage changes in clinical scores. Treatment effect sizes are quantified using partial eta squared with the level of significance set at p < 0.05.

Study Type

Interventional

Enrollment (Estimated)

200

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Greece
      • Kavala, Greece, 64100
      • Serres, Greece, 62100
        • Recruiting
        • Laboratory of Neuromechanics, Department of Physical Education and Sport Science, Aristotle University of Thessaloniki
        • Contact:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Individuals with Muscle Injury

Inclusion Criteria:

  • Age over 18 years.
  • Athletes: amateur soccer players or sprinters with regular, systematic training.
  • Suspected Grade I or II hamstring strain.
  • Cessation of training due to injury.
  • No surgical intervention in the previous year (for initial assessment as potential participants).

Exclusion Criteria:

  • History of injury to the same muscle (ipsilateral side) within the last 6 months.
  • Other injury to the posterior aspect of the thigh.
  • Other injuries or chronic pain in the trunk or lower limbs.
  • Use of non-steroidal anti-inflammatory drugs (NSAIDs) in the 3 months prior to the injury.

Individuals with Acute Low Back Pain

Inclusion Criteria:

  • Age over 18 years.
  • Pain located between the lower ribs and the gluteal folds (top of the buttocks).
  • Pain occurred on fewer than half of the days over the preceding six months.
  • Pain intensity $\ge$ 6/10 on the Visual Analogue Scale (VAS).

  • Pain related to one or more of the following:

    • Lumbar facet joints
    • Sacroiliac joints
    • Lumbar intervertebral discs
    • Muscles, tendons, or ligaments of the lumbar and sacral region
    • Other bony structures of the lumbar spine

  • Discontinuation of non-steroidal anti-inflammatory drugs (NSAIDs) or analgesics:

    • 1 day prior to measurement
    • 48 hours after measurement

Exclusion Criteria:

  • Radiographic evidence of inflammatory disease affecting the spine.
  • Spinal fracture.
  • Significant genetic structural abnormality of the spine.
  • Pregnancy.
  • Psychiatric disorders.
  • Receipt of systemic medication or treatment in the last 3 months.
  • Presence of neurological deficits (sensory, motor, or reflexes).
  • Receipt of TENS or TECAR therapy within the last year.

Individuals with Chronic Low Back Pain

Inclusion Criteria:

  • Episodes of low back pain (between the lower rib margin and the gluteal fold) for at least half of the days during the last 6 months.
  • Pain intensity $\ge$ 20% on the Visual Analogue Scale (VAS).

Exclusion Criteria:

  • Spinal stenosis.
  • Radiographic evidence of inflammatory disease affecting the spine.
  • Vertebral fracture.
  • Presence of spondylolisthesis or spondylolytic lesion (spondylolysis).
  • Significant genetic structural abnormality of the spine.
  • Daily, severe low back pain.
  • Pregnancy.
  • Use of medications that might influence heart rate or blood pressure.
  • Psychiatric disorders.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: TECAR therapy
Participants in this arm receive high-frequency electrical current transfer (TECAR) using the Winback system at 0.5 MHz in capacitive mode with 40-60% intensity. In the acute phase, participants receive a single 20-minute session for acute hamstring strain or acute low back pain. In the chronic phase, participants receive 10 sessions (3 times per week) for hamstring injury or chronic low back pain.
Device: Radiofrequency Energy Transfer
Radiofrequency Electrical Currents (TECAR) will be delivered using a winback system (Winback, Villeneuve-Loubet, France) propagating radiofrequency waves of 448 kHz using metallic electrodes via a coupling medium. Radiofrequencies will be used in the capacitive mode , which aims to treat superficial /soft tissues in the area. The "active" plate will be applied sequentially on the skin in the injured or painful region. The base plate will be located to the other side of the injured body region (for back thigh muscle injuries, for example, the base plate will be located on the frontal thigh area, to close the current circuit. Therapy will be applied for 20 minutes, with a target intensity of 40% and a frequency of 0.5Mhz.
Other Names:
  • TECAR
Device: Transcutaneous Nerve Stimulation
Transcutaneous nerve stimulation (TENS) will be delivered using a Chattanooga Intellect Advanced Combo system (Chattanooga, Hixson, TN 3 7343, USA). Two electrodes will be placed on the skin at a distance so that they cover the entire painful area. The TENS asymmetric biphasic mode (phase 300 ms, frequency 80Hz, continuous cycle) will be applied. The intensity will be adjusted between 0 and 110A, such that it is tolerable by the participant. The total application time will be 20 minutes or equal to that applied for the TECAR group.
Other Names:
  • TENS
Active Comparator: TENS Therapy
Participants in this arm receive transcutaneous electrical nerve stimulation (TENS) using a Chattanooga system with an asymmetric biphasic mode at 80 Hz. In the acute phase, participants receive a single 20-minute session for acute hamstring strain or acute low back pain. In the chronic phase, participants receive 10 sessions (3 times per week) for hamstring injury or chronic low back pain.
Device: Radiofrequency Energy Transfer
Radiofrequency Electrical Currents (TECAR) will be delivered using a winback system (Winback, Villeneuve-Loubet, France) propagating radiofrequency waves of 448 kHz using metallic electrodes via a coupling medium. Radiofrequencies will be used in the capacitive mode , which aims to treat superficial /soft tissues in the area. The "active" plate will be applied sequentially on the skin in the injured or painful region. The base plate will be located to the other side of the injured body region (for back thigh muscle injuries, for example, the base plate will be located on the frontal thigh area, to close the current circuit. Therapy will be applied for 20 minutes, with a target intensity of 40% and a frequency of 0.5Mhz.
Other Names:
  • TECAR
Device: Transcutaneous Nerve Stimulation
Transcutaneous nerve stimulation (TENS) will be delivered using a Chattanooga Intellect Advanced Combo system (Chattanooga, Hixson, TN 3 7343, USA). Two electrodes will be placed on the skin at a distance so that they cover the entire painful area. The TENS asymmetric biphasic mode (phase 300 ms, frequency 80Hz, continuous cycle) will be applied. The intensity will be adjusted between 0 and 110A, such that it is tolerable by the participant. The total application time will be 20 minutes or equal to that applied for the TECAR group.
Other Names:
  • TENS
No Intervention: Control group
Participants in this arm serve as the control group and do not receive any active electrophysical intervention during the assessment periods. For the acute phase, outcomes are measured over a 48-hour window. For the chronic phase, outcomes are measured at baseline and follow-up intervals to account for natural recovery and baseline variations.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in pain Intensity
Time Frame: ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
Visual analogue scale. Scale ranges from 0 to 10. 0 indicates no pain and 10 maximum intensity pain
ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
Change in sit and reach test measurement
Time Frame: ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
From supine position, with the feet in contact with a wooden box and the trunk flexed, participants attempt to reach with their hands as far as posible. Score is measured in cm. A higher measurement indicates higher flexibility
ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
Change in straight leg raising test
Time Frame: ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: before, month 3, month 6
From supine position, the tester raises one leg (with the knee flexed about 10-20 degrees) until discomfort is reported. The range of motion (in degrees) is stored.
ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: before, month 3, month 6
Change in Oswestry index score
Time Frame: ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
A questionnaire which provides a score which reflects function in activities of daily living for those with acute or chronic back pain. It consists of 10 categories of questions, with a total sum of 50. Score is expressed as a percentage of 50, where 0% indicates no functional disability and pain. 100% indicates maximum functional disability and pain
ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
Change in prone flexibility test
Time Frame: CHRONIC PHASE STUDY: Before, month 3, month 6
From the prone position, the tester flexes the knee of the participant. The maximum range of motion is stored in degrees
CHRONIC PHASE STUDY: Before, month 3, month 6

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Functional Assessment Scale for Acute Hamstring Injuries (FASH)
Time Frame: ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
A questionnaire for the assessment of hamstring injury severity and its impact on function of injured individuals. The questionnaire consists of 10 items, each given a score from 0 to 10, where 10 represents a high level of physical ability and 0 represents complete disability. Items scores are then added, such that a lowest total score indicates more severe symptoms.
ACUTE EFFECTS STUDY: Day before, day 0, day 1, day 2 CHRONIC EFFECTS STUDY: Before, month 3, month 6
Change in single leg balance test center of pressure
Time Frame: CHRONIC EFFECTS STUDY: Before, month 6
Displacement of center of pressure during a 30s single-leg standing test on a pressure platform. A greater center of pressure displacement indicates less postural stability.
CHRONIC EFFECTS STUDY: Before, month 6

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Aristotle University Of Thessaloniki

Investigators

  • Principal Investigator: Eleftherios Kellis, Ph.D., Professor
  • Study Director: Thomas Apostolou, M.D., International Hellenic University
  • Principal Investigator: Paris Iakovidis, Ph.D., International Hellenic University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

April 30, 2022

Primary Completion (Estimated)

May 31, 2028

Study Completion (Estimated)

December 31, 2029

Study Registration Dates

First Submitted

April 9, 2022

First Submitted That Met QC Criteria

April 19, 2022

First Posted (Actual)

April 25, 2022

Study Record Updates

Last Update Posted (Actual)

April 21, 2026

Last Update Submitted That Met QC Criteria

April 16, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • TECAR22#1

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

De-identified individual participant data (IPD) that underlie the results reported in this study may be made available upon reasonable request. However, under no circumstances will identifiable personal information, medical records, or any data that could compromise participant confidentiality be provided. All shared data will be strictly anonymized and restricted to numerical outcome measurements to ensure full compliance with privacy regulations and the study's ethics protocol

IPD Sharing Time Frame

Beginning 6 months and ending 24 months after the publication of results.

IPD Sharing Access Criteria

Data will be made available to researchers who provide a methodologically sound proposal. Requests must be directed to the corresponding author and are subject to approval based on the study's ethical and privacy guidelines.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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