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Myofascial Pain Syndrome (MPS)NCT07315776

Effects of Electrical Muscle Stimulation on Myofascial Pain Syndrome

A study testing Therapist-assisted Passive stretching (PS), The two-combination of EMS+AS and Trigger point pressure release (TPR) in people with Myofascial Pain Syndrome (MPS), run by University of Bath at 1 site in United Kingdom.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The goal of this clinical trial is to determine if Electrical Muscle Stimulation (EMS) combined with Active Stretching (AS) (EMS+AS) and EMS+AS combined with Trigger Point Pressure Release (TPR) (EMS+AS+TPR) are effective treatments for Myofascial Pain Syndrome (MPS) in working adults. Read more about this study

Who is it for?
Ages 18 years and older
Conditions the study is for
Myofascial Pain Syndrome (MPS)
What is being tested?
Therapist-assisted Passive stretching (PS), The two-combination of EMS+AS and Trigger point pressure release (TPR)
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
65 participants
Where
1 siteUnited Kingdom
Study dates
25 Nov 2022to 20 Sep 2025
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Participants over 18 years old with either active or latent myofascial trigger points in the trapezius muscle were diagnosed with MPS by a General Practitioner (GP).
  • Participants have no history of chronic diseases (cancer, cervical nerve root compression, heart arrhythmias, including hyperthyroid, muscle weakness, seizure, skin infection at the upper back, spinal cord injury, stroke).
  • Participants have ability to move the upper limbs.
  • Participants reported no use of pacemakers or strong pain relievers, no allergies to metals, gels, or cleaning products, and no pre-existing severe muscle soreness.

Who cannot join

  • Participants less 18 years old with no myofascial trigger points in the trapezius muscle.
  • Participants to have history of chronic diseases (cancer, cervical nerve root compression, heart arrhythmias, including hyperthyroid, muscle weakness, seizure, skin infection at the upper back, spinal cord injury, stroke).
  • Participants cannot move the upper limbs.
  • Participants reported use of pacemakers or strong pain relievers, and allergies to metals, gels, or cleaning products, and pre-existing severe muscle soreness.

Trial locations and contacts

1 site in 1 country.

United Kingdom1 site
  • Department of Electronic and Electrical Engineering

    Bath, BA2 7AY

Other trials in United Kingdom

About this study

The goal of this clinical trial is to determine if Electrical Muscle Stimulation (EMS) combined with Active Stretching (AS) (EMS+AS) and EMS+AS combined with Trigger Point Pressure Release (TPR) (EMS+AS+TPR) are effective treatments for Myofascial Pain Syndrome (MPS) in working adults. The study will also assess the safety of the EMS+AS intervention. The main questions it aims to answer are: Do EMS+AS and EMS+AS+TPR lead to greater pain reduction, increased pressure pain threshold, and improved surface electromyography (sEMG) activity when compared to standard treatments? Furthermore, what is the participant feedback regarding EMS+AS and other treatments?

Researchers will compare EMS+AS to passive stretching (PS) and TPR to see if EMS+AS and EMS+AS+TPR are effective in treating myofascial trigger points in the trapezius muscle.

Participants will receive seven interventions across a single visit, including PS, EMS+AS, TPR, TPR combined with AS (TPR+AS), EMS+AS+TPR, Sham stimulation, and Transcutaneous Electrical Nerve Stimulation (TENS). Each treatment will consist of three 10-second sets with a 10-second rest between sets, and a 2-minute break provided between different treatments. Participants will have measurements taken on changes in pain intensity, pressure pain threshold, and sEMG activity during trapezius action pre- and post-treatment. Additionally, participants will report personal information, previous MPS treatments, and baseline health status, and provide feedback on satisfaction, treatment preferences, exercise knowledge for MPS prevention, and qualitative comments. For supplementary data, we selected only the EMS+AS and TPR interventions with the same protocol to evaluate changes in range of motion and changes in trigger point size and trapezius thickness (both at rest and during stretching) via ultrasound imaging.

Read the detailed description

The main study measures included changes in pain intensity, pressure pain threshold, and sEMG activity. The supplementary study measures included ultrasound images and range of motion.

Being tested
Therapist-assisted Passive stretching (PS), The two-combination of EMS+AS, Trigger point pressure release (TPR), Trigger point pressure release combined with active stretching (TPR+AS), The triple combination therapy of EMS+AS+TPR
Keywords
Electrical Muscle Stimulation, Myofascial pain syndrome, trigger point pressure release, electromyography, pain intensity, pressure pain threshold, ultrasound images
Medical subject headings
Myofascial Pain Syndromes, Pain

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Therapist-assisted Passive stretching (PS)Other

    Also called PS

    The therapist stretched the upper trapezius muscle via shoulder depression and neck deviation. The middle trapezius muscle was stretched using scapular protraction while simultaneously stabilizing the mid-spine and gently pulling the arm inward.

  • The two-combination of EMS+ASOther

    Also called EMS+AS

    Electrical Muscle Stimulation combined with Active Stretching: The EMS component utilized parameters of 20 Hz frequency and 100 µs pulse width, with the amplitude adjusted individually for intensity. The EMS electrodes were placed across the muscle fibers with a 1 cm inter-electrode distance. This placement was specifically designed to restrict the electrical field, thereby inducing a local muscle contraction that opposes the direction of the active stretch being performed concurrently.

  • Trigger point pressure release (TPR)Other

    Also called TPR

    Trigger point Pressure Release (TPR): The therapist utilized a PAIN TEST™ FPX series pressure gauge (Wagner Instruments). A round rubber 1 cm2 force gauge probe was applied directly on the MTP by gradually increasing the pressure until the participant reached their maximum pressure tolerance level.

  • Trigger point pressure release combined with active stretching (TPR+AS)Other

    Also called TPR+AS

    Trigger point Pressure Release combined with Active Stretching (TPR+AS) was performed by applying active stretching of the trapezius muscle concurrently with TPR, using the same protocol as the standalone TPR intervention.

  • The triple combination therapy of EMS+AS+TPROther

    Also called EMS+AS+TPR

    Electrical Muscle Stimulation combined with Active Stretching during Trigger point Pressure Release (EMS+AS+TPR): This triple combination therapy utilized the EMS+AS component protocol concurrently with the TPR intervention, applying the identical protocols established for the standalone EMS+AS and TPR procedures.

  • Transcutaneous electrical nerve stimulation (TENS)Other

    Also called TENS

    Transcutaneous Electrical Nerve Stimulation (TENS) was applied using the conventional protocol (60 Hz,100 µs,5 mA) with two electrodes placed directly over the MTP region, without stretching.

  • Sham stimulation combined with active stretching (SS+AS)Other

    Also called SS+AS

    Sham stimulation combined with active stretching (SS+AS): Participants performed AS using the same EMS device and electrode placement as in the EMS+AS protocol. However, no electrical current was applied. The procedure began with a conversation about the treatment from the researcher while the current amplitude was reduced from 1 mA to 0 mA during the trapezius muscle stretching, accompanied by a beeping sound to simulate stimulation. Participants were subsequently informed that this was the intended treatment.

Study groups in NCT07315776
Study groupRoleWhat they receive
Therapist-assisted Passive stretching (PS)Active comparatorPassive Stretching with Therapist Assistance: The protocol consisted of three sets of stretching. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: Therapist-assisted Passive stretching (PS)
The two-combination of EMS+ASExperimentalElectrical Muscle Stimulation (EMS) combined with Active Stretching (AS) was applied to the upper or middle trapezius muscle to facilitate muscle elongation. The protocol consisted of three sets of performing. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: The two-combination of EMS+AS
Trigger point pressure release (TPR)Active comparatorTrigger Point Pressure Release (TPR): TPR was directly applied to the MTP of upper or middle trapezius muscle.The protocol consisted of three sets of performing. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: Trigger point pressure release (TPR)
Trigger point pressure release combined with active stretching (TPR+AS)OtherTrigger Point Pressure Release (TPR) combined with Active Stretching (AS) was performed either by using neck deviation for the upper trapezius muscle or by using scapula protraction for the middle trapezius muscle during TPR. The protocol consisted of three sets of performing. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: Trigger point pressure release combined with active stretching (TPR+AS)
The triple combination therapy of EMS+AS+TPRExperimentalThis triple combination therapy was applied to enhance MTP release in the upper or middle trapezius muscles. The protocol consisted of three sets of performing. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: The triple combination therapy of EMS+AS+TPR
Transcutaneous electrical nerve stimulation (TENS)Active comparatorTranscutaneous Electrical Nerve Stimulation (TENS) was applied on the upper or middle trapezius muscles without stretching. The protocol consisted of three sets of operating. Each set was performed for 10 seconds and followed by a 10-second break, totaling one minute for the single session.
Receives: Other: Transcutaneous electrical nerve stimulation (TENS)
Sham stimulation combined with active stretching (SS+AS)Sham comparatorSS+AS consisted only of active stretching of the upper or middle trapezius muscle, with no electrical current applied from EMS device. Self-stretching was performed for three sets, with each 10-second stretch followed by a 10-second break, resulting in a total session time of one minute.
Receives: Other: Sham stimulation combined with active stretching (SS+AS)

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in Pain intensity

    Changes in pain intensity before and after treatment were measured using a numeric rating scale (0-10), where 0 represents no pain and 10 represents the worst possible pain. A reduced score indicates a better outcome.

    Measured: Baseline and Day 1 (immediately post-intervention)

  2. Changes in pressure pain threshold

    Changes in pressure pain threshold between before and after treatment were measured using a digital algometer (Wagner, Greenwich, USA). Pressure pain threshold was measured in kilogram force (kgf) or kilograms per square centimeter (kg/cm²). An increased score indicates a better outcome.

    Measured: Baseline and Day 1 (immediately post-intervention)

  3. Changes in median frequency of EMG activity

    Changes in the median frequency of surface electromyography (EMG) before and after treatment were recorded in hertz (Hz) using a 16-channel sEMG (Delsys Trigno Maize Sensor system). Changes in median frequency reflect physiological changes in muscle function. An increase in median frequency during trapezius muscle activity indicates physiological improvement.

    Measured: Baseline and Day 1 (immediately post-intervention)

  4. % maximum volunatary contraction (MVC) improvement

    %MVC improvement of EMG activity before and after treatment was recorded in percent (%) after calculating the root mean square normalized to pre-treatment values using a 16-channel sEMG (Delsys Trigno Maize Sensor system). An increase in %MVC during trapezius muscle activity indicates muscle function improvement.

    Measured: Baseline and Day 1 (immediately post-intervention)

Secondary outcomes (4)
  1. Changes in range of motion (ROM) of neck deviation

    Changes in ROM of neck deviation before and after treatment were assessed through photographic analysis. Photographs of participants are analyzed using ImageJ software, and ROM was recorded in degrees. An increase in ROM indicates improved upper trapezius muscle flexibility.

    Measured: Baseline and Day 1 (immediately post-intervention)

  2. Changes in myofascial trigger point (MTP) size

    Changes in MTP size before and after treatment were assessed via ultrasound imaging and analyzed using ImageJ software. MTP size was recorded in square millimeters (mm²). A decrease in MTP size indicates improved treatment outcomes.

    Measured: Baseline and Day 1 (immediately post-intervention)

  3. Changes in echointensiy at the myofascial trigger point (MTP)

    Changes in echo intensity at the MTP before and after treatment were assessed via ultrasound imaging and analyzed using ImageJ software. The echo intensity at the MTP was recorded in pixels. Changes in echo intensity reflect transient alterations in fluid accumulation or tissue structure due to fibrotic remodeling at the MTP. An increase in MTP echo intensity indicates decreased fluid accumulation, which may predict an improved treatment outcome.

    Measured: Baseline and Day 1 (immediately post-intervention)

  4. Changes in trapezius muscle thickness

    Changes in trapezius muscle thickness at rest and during stretching were assessed via ultrasound imaging and analyzed using ImageJ software. Trapezius muscle thickness was recorded in millimetre. The observed reduction in TM thickness at rest and during stretching suggests decreased muscle tension, reflecting muscle tone improvement following treatment.

    Measured: Baseline and Day 1 (immediately post-intervention)

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted2 Jan 2026
  2. Study start25 Nov 2022
  3. Primary completion28 Mar 2024
  4. Study completion20 Sep 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Care provider, Outcomes assessor
Enrolment
65 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07315776
Sponsor's protocol ID
EP 22 081
Other IDs
4961-6056
Status last verified
Dec 2025
First submitted
27 Nov 2025
Last updated
2 Jan 2026
Results posted
No
Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: "Participants' data being shared within the research team", as noted in the consent form. Data will not be shared with other researchers unless they formally join the research team.

Questions about this trial

What is this clinical trial studying?

A study testing Therapist-assisted Passive stretching (PS), The two-combination of EMS+AS and Trigger point pressure release (TPR) in people with Myofascial Pain Syndrome (MPS), run by University of Bath at 1 site in United Kingdom.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 4 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jan 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in Pain intensity (time frame: Baseline and Day 1 (immediately post-intervention)). The study lists 4 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jan 2026.

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