Acute Effects of TENS on Cervical Muscle Stiffness and Pain in Neck Pain

NCT ID: NCT07244861

Last Updated: 2025-11-24

Basic Information

• Recruitment Status: ENROLLING_BY_INVITATION
• Clinical Phase: NA
• Total Enrollment: 24 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2025-09-23
• Study Completion Date: 2025-12-15

Brief Summary

This randomized controlled trial investigates the acute effects of transcutaneous electrical nerve stimulation (TENS) on passive cervical muscle stiffness (MyotonPro "dynamic stiffness", N/m) and pain (0-10 VAS) in adults with chronic/mechanical neck pain. Participants will be allocated 1:1 to TENS or control/sham. Outcomes are measured immediately before and immediately after a single 15-minute session.

Detailed Description

Background/Rationale: TENS modulates superficial afferent input and may reduce pain and muscle tone. However, its immediate impact on objective passive muscle stiffness measured by a handheld myotonometer (MyotonPro) in neck pain is insufficiently characterized. This trial tests whether a brief, low-risk intervention produces measurable changes in mechanical muscle properties and perceived pain in a short time window.

Objectives/Hypotheses:

Primary objective: Determine whether conventional TENS acutely reduces dynamic stiffness of the upper trapezius compared with control/sham.

Secondary objectives: Evaluate pain (VAS), additional MyotonPro parameters (frequency/tone, logarithmic decrement, relaxation time, creep), and safety/tolerability.

Hypothesis: TENS will show a significant group × time interaction favoring TENS over control/sham.

Design: Single-center (optionally multi-center), parallel-group, randomized (1:1) RCT. Masking: at minimum outcome assessor-blinded; participant blinding if sham TENS is used.

Sample Size: n = 24 (12 per arm), based on a priori power analysis (f≈0.40, α=0.05, power=0.95) for a 2×2 mixed design.

Intervention (TENS): Conventional mode; ~80 Hz, ≤150 µs pulse width; 15 minutes; intensity "strong but tolerable" without visible muscle contraction. Electrodes placed over the most painful/stiff segments (typically upper trapezius and/or suboccipital region), preferably bilateral.

Control/Sham: No intervention or sham TENS (electrodes applied; intensity raised to sensation then reduced below perception/zero; device indicators remain on).

Assessments & Timing:

Time points: T0 (pre-session), T1 (immediately post-session).

Primary outcome: Upper trapezius dynamic stiffness (N/m)-three repetitions averaged at a standardized anatomical landmark.

Secondary outcomes: Pain VAS (0-10); MyotonPro frequency/tone, decrement, relaxation time, creep on upper trapezius ± SCM ± cervical extensors; adverse events/tolerability. (Neck Disability Index may be collected at baseline for descriptive characterization.)

Statistical Plan: Mixed-effects repeated-measures analysis with Group (TENS vs control/sham) × Time (T0 vs T1); assumption checks with robust alternatives/transformations as needed; multiple-comparison controls; effect sizes reported.

Eligibility (summary): Adults 18-50 years with neck pain VAS ≥3/10. Key exclusions include pacemaker, pregnancy, recent invasive procedures (≤6 weeks), significant dermatologic issues at electrode sites, cervical radiculopathy/neurological signs, acute neck injury. (Full list in Eligibility.)

Safety: Low-risk, non-invasive procedure. Expected adverse effects are minor (e.g., transient discomfort or skin irritation). AE/SAE monitoring is prospective; the session will be stopped if intolerable symptoms occur.

Conditions

Neck Pain; Chronic Neck Pain; Muscle Stiffness; Transcutaneous Electrical Nerve Stimulation

Study Design

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

Study Groups

TENS

Participants receive a single session of conventional TENS targeting painful/stiff cervical muscle regions (typically upper trapezius ± suboccipital) with immediate post-session assessments.

Group Type: EXPERIMENTAL

Transcutaneous Electrical Nerve Stimulation

Intervention Type: DEVICE

Conventional mode TENS, frequency \~80 Hz, pulse width ≤150 µs, duration 20 minutes. Intensity set to "strong but tolerable" without visible muscle contraction. Electrodes placed bilaterally over the most painful/stiff segments (e.g., upper trapezius midpoint along C7-acromion line; adjustments per comfort

Sham TENS

Intervention Type: DEVICE

Electrodes applied at the same anatomical sites as the active arm. Device indicators remain on; intensity is ramped to perception briefly and then reduced to sub-sensory/zero so that no effective current is delivered for the remainder of the 20-minute session. Procedures and clinician-participant interactions mirror the active arm

Sham TENS

Participants undergo a sham stimulation session with identical setup and timing to mimic TENS without delivering therapeutic current.

Group Type: SHAM_COMPARATOR

Transcutaneous Electrical Nerve Stimulation

Intervention Type: DEVICE

Conventional mode TENS, frequency \~80 Hz, pulse width ≤150 µs, duration 20 minutes. Intensity set to "strong but tolerable" without visible muscle contraction. Electrodes placed bilaterally over the most painful/stiff segments (e.g., upper trapezius midpoint along C7-acromion line; adjustments per comfort

Sham TENS

Intervention Type: DEVICE

Electrodes applied at the same anatomical sites as the active arm. Device indicators remain on; intensity is ramped to perception briefly and then reduced to sub-sensory/zero so that no effective current is delivered for the remainder of the 20-minute session. Procedures and clinician-participant interactions mirror the active arm

Interventions

Transcutaneous Electrical Nerve Stimulation

Conventional mode TENS, frequency \~80 Hz, pulse width ≤150 µs, duration 20 minutes. Intensity set to "strong but tolerable" without visible muscle contraction. Electrodes placed bilaterally over the most painful/stiff segments (e.g., upper trapezius midpoint along C7-acromion line; adjustments per comfort

Intervention Type: DEVICE

Sham TENS

Electrodes applied at the same anatomical sites as the active arm. Device indicators remain on; intensity is ramped to perception briefly and then reduced to sub-sensory/zero so that no effective current is delivered for the remainder of the 20-minute session. Procedures and clinician-participant interactions mirror the active arm

Intervention Type: DEVICE

Other Intervention Names

Conventional TENS; TENS therapy; Placebo TENS

Eligibility Criteria

Inclusion Criteria

• Age 18-50 years.

Neck pain VAS ≥ 3/10 at screening and on test day.

Clinical diagnosis of chronic or mechanical neck pain (≥6 weeks).

Able to understand study procedures and provide written informed consent.

Willing to refrain from analgesics/muscle relaxants and vigorous neck/shoulder exercise for 24 hours before testing.

Exclusion Criteria

• Cervical radiculopathy or neurological signs (myotomal weakness, dermatomal sensory loss, reflex changes).

Recent invasive procedures to the neck/shoulder (e.g., surgery, injections, radiofrequency/neurotomy) within 6 weeks.

Pacemaker/implantable cardioverter, or other active implanted electronic device.

Pregnancy or planning pregnancy.

Skin conditions at electrode sites (open wounds, infection, severe dermatitis) or known allergy to electrode adhesive/gel.

History of epilepsy or unexplained syncope.

Acute neck trauma (<6 weeks) or red flags (fracture, malignancy, infection, inflammatory rheumatic disease).

Systemic disorders likely to affect outcomes (e.g., uncontrolled diabetes with neuropathy, severe cardiovascular disease, fibromyalgia with widespread pain).

Ongoing electrotherapy to the neck region or botulinum toxin injections to cervical muscles within 3 months.

Inability to comply with procedures (e.g., severe communication/cognitive impairment), or insufficient proficiency in Turkish to complete measures.

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 50 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Amasya University

OTHER

Sponsor Role: collaborator

Bangor University

OTHER

Sponsor Role: collaborator

Ataturk University

OTHER

Sponsor Role: collaborator

Erzurum Technical University

OTHER

Sponsor Role: lead

Responsible Party

esedullah akaras

Dr.

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Gökhan YAGİZ, Dr.

Role: STUDY_DIRECTOR

Amasya University

Locations

Erzurum Technical University Faculty of Health Sciences

Erzurum, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

Erzurum Technical University

Identifier Type: OTHER

Identifier Source: secondary_id

ETU-TENS-NECK-RCT-02

Identifier Type: -

Identifier Source: org_study_id