Myofascial Pain Syndrome, Trigger Points
Conditions
Keywords
Trigger points, Vagus Nerve Stimulation, Parasympathetic System
Brief summary
This randomized controlled trial aimed to evaluate the efficacy of non-invasive vagus nerve stimulation (nVNS) compared to ischemic compression (trigger point massage) and exercise in treating trigger points in the upper trapezius muscle. Ninety participants aged 18-55 with at least two trigger points were randomly assigned to three groups: nVNS, ischemic compression, or exercise (control). Interventions were administered over 10 sessions (3 times per week). Outcomes included pain intensity (Visual Analog Scale, VAS), trigger point number, pain pressure threshold (algometer), neck function (Copenhagen Neck Functional Disability Scale, KBFÖS), well-being (WHO-5 Well-Being Index), and functional mobility. The nVNS group demonstrated statistically significant improvements in all outcomes compared to the other groups (p \< 0.05).
Detailed description
Myofascial pain syndrome (MPS) is characterized by trigger points-hyperirritable spots in skeletal muscle associated with pain, stiffness, and reduced function. The upper trapezius muscle is a common site for trigger points, contributing to neck pain and disability. Traditional treatments include ischemic compression and exercise, but non-invasive vagus nerve stimulation (nVNS) has emerged as a promising modality due to its ability to modulate pain pathways and autonomic function. This study investigated whether nVNS is more effective than ischemic compression or exercise in reducing pain and improving function in patients with trapezius trigger points. Participants were randomized into three groups (n=30 each)
Interventions
DEVICEVagus Nerve Stimulation (nVNS)
Arm 1 (Vagus Nerve Stimulation (nVNS)) is an experimental intervention, as it tests a novel approach (non-invasive vagus nerve stimulation) for trigger point treatment.
PROCEDUREIschemic Compression
Arm 2 (Ischemic Compression) is an active comparator, as it uses a standard treatment (trigger point massage) commonly applied for myofascial pain.
BEHAVIORALExercise (Control)
Arm 3 (Exercise (Control)) is explicitly labeled as the control group in your document, using a standard exercise program, which aligns with an active comparator (since it's an active intervention rather than a placebo or no intervention).
Sponsors
Bahçeşehir University
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)
Masking description
This study employs single blinding, where the outcomes assessors are masked to the participants' group assignments. Participants are randomized into one of three groups (non-invasive vagus nerve stimulation, ischemic compression, or exercise), and the interventions are administered by unblinded study personnel. To minimize bias, assessors responsible for measuring outcomes, including pain intensity (Visual Analog Scale), number of trigger points, pain pressure threshold (algometer), neck function (Copenhagen Neck Functional Disability Scale), well-being (WHO-5 Well-Being Index), and functional mobility, are unaware of the intervention each participant receives. Participants and intervention providers are not blinded due to the nature of the interventions.
Intervention model description
This study employs a parallel assignment model with three distinct intervention arms. Ninety participants with trigger points in the upper trapezius muscle are randomly assigned to one of three groups (n=30 each): non-invasive vagus nerve stimulation (nVNS), ischemic compression (trigger point massage), or exercise (control). Each group receives their respective intervention over 10 sessions (3 times per week for 4 weeks). The parallel design ensures that participants remain in their assigned group throughout the study, with no crossover. Outcomes, including pain intensity, trigger point number, pain pressure threshold, neck function, well-being, and functional mobility, are assessed at baseline and post-intervention (week 4). Single blinding (outcomes assessor) is implemented to minimize bias in outcome measurements.
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* Age 18-55 years. * Presence of at least two trigger points (active or latent) in the upper trapezius muscle, confirmed by palpation. * Ability to provide informed consent.
Exclusion criteria
* History of cervical spine surgery or trauma. * Neurological disorders (e.g., epilepsy, stroke). * Pregnancy or breastfeeding. * Use of pacemakers or other implanted electrical devices. * Active infection or skin lesions at the stimulation site. * Recent use of botulinum toxin or other trigger point injections.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Pain Intensity (VAS)(Visual Analog Scale ) | Baseline and post-intervention (week 4) | Measured using the Visual Analog Scale (0-10 ), where 0 indicates no pain and 10 indicates worst possible pain. |
| Number of Trigger points | Measurements were taken pre- and post-intervention.(week 4) | Count of active and latent trigger points in the upper trapezius muscle, assessed by palpation. |
| Pain Pressure Threshold (Algometer) | Measurements were taken pre- and post-intervention. (week 4) | Measured using a digital algometer (kg/cm²) at trigger point sites to assess pain sensitivity. |
| Neck Function (CNFDS(Copenhagen Neck Functional Disability) | Measurements were taken pre- and post-intervention. (week 4) | Assessed using the Copenhagen Neck Functional Disability Scale, evaluating neck-related disability (0-30, higher scores indicate greater disability). |
| WHO-5(World Health Organization-Five Well-Bing Index) | Measurements were taken pre- and post-intervention. (week 4) | Description: Measured using the WHO-5 Well-Being Index, a 5-item scale (0-25, higher scores indicate better well-being) |
Countries
Turkey (Türkiye)
Outcome results
None listed