Dry Needling and Low-level Laser Therapy to Treat Myofascial Pain

The present study has the objective to evaluate the effects of dry needling and photobiomodulation application in the treatment of trigger points in upper trapezius on women with myofascial pain. The specific objectives are: 1) To evaluate the pain level before, during, and after the dry needling and photobiomodulation applications on the trigger point; 2) To identify the pain pressure threshold before and after dry needling and photobiomodulation applications on the trigger point; 3) To verify the electromyographic activity of upper trapezius before and after the proposed treatments; and 4) To compare the effects fond intra and inter-groups for the applications of dry needling, dry needling and photobiomodulation, and control protocol.

The sample will be composed by 20 subjects in each group, a total of 60 subjects, according to a convenience sample based on review studies of Cagnie at al., 2015, and Espejo-Antúnez et al., 2017.

The study will be performed at the Laboratory of Evaluation and Rehabilitation of the Locomotor Apparatus (LARAL), located at Universidade Federal de Santa Catarina, Campus Araranguá, Santa Catarina, Brazil. Women, with age between 18 and 65 years old, students, workers, and professors at Universidade Federal de Santa Catarina (UFSC) will be invited to participate in the research. The invitation of subjects to participate in the study will be done through digital and printed folders that will be delivered at UFSC and on the social media. Those subjects that show interest to participate will be forwarded to an evaluation selection where it will be identified if the participant fits the inclusion criteria and where the Consent Form will be presented.

The active trigger point in upper trapezius will be localized through manual palpation and the location will be marked with a special pen for the skin. A second mark located 1.5 centimeters medially from the trigger point will be made in all subjects. The trigger point identification will follow Simons et al. criteria, featuring 3 of 4itens: (1) presence of palpable taut band in the muscle; (2) presence of hypersensitive spot inside the taut band; (3) subject recognize the familiar pain; and (4) painful limitation of the range of motion during total stretch.

The surface electromyography (EMG) will be used to evaluate the muscle recruitment pattern. Disposable electrodes, made with polyethylene foam and with hypoallergenic adhesive, solid gel adherent, bipolar contact of Silver/Silver Chloride (Ag/AgCl), will be used and positioned with 20mm of distance between poles. The Medtrace® reference electrode will be positioned in the ipsilateral wrist of the data collection. The electrodes will be positioned in the upper trapezius muscle as recommended by Surface ElectroMyoGraphy for the Non-Invasive Assessment of Muscles (SENIAM).

The Visual Analogue Scale (VAS) will be used so the subjects can graduate their pain in shoulder and neck regions. The VAS level of pain will be acquired before the intervention, soon after the intervention, 30 minutes after the intervention, one week and one month after the intervention.

Pressure algometry will be used to evaluate the pain pressure threshold (PPT). This measured will be obtained before the intervention (baseline), soon after the intervention, and 30 minutes after the intervention. The equipment will be positioned on the trigger point mark and the subject will be instructed to report when the sensation changes from pressure to pain. The force measured in kilograms per square centimeter (kg / cm²) will correspond to the quantity of pressure needed so the subject report change in pressure pain sensation.

The Neck Disability Index (NDI) is a unidimensional questionnaire composed of 10 items that have the aim to evaluate the limitation caused by pain and disability on the neck (30). This questionnaire will be self-applied and the subject will answer it before the intervention, one week and one month after intervention.

The Dry Needling (DN) protocol will be performed in one session. It will be used acupuncture needles, individually packaged and sterilized, with 0.25 mm of thickness and 0.40 mm of length. The therapist, then, will perform the grip in upper trapezius on the site of one of the two previously marked locations, according to the subject group allocation, and will insert the needle in the skin with help of a guide tube and will deepen the needle approximately 10 to 15 mm inside the trigger point. The needle will be moved up and down as in the "fast-in and fast-out" technique described by Hong. The movement will be repeated during 30 seconds in a cadence of approximately 1 Hz. The protocol will be the same for the groups that will receive the application directly on the trigger point and for the group that will receive the application away from the trigger point.

The photobiomodulation protocol will be performed using an equipment from Ibramed Equipamentos Médicos® of Aluminized Gallium Arsenide (AsGaAl) laser diode, with a wavelength of 830 nm, fluency of 20 J/cm², 30 milliwatts (mW), beam area of 0.116 cm², energy of 2,3 J per point, continuous beam. The low-level laser therapy (LLLT) will be applied for 30 seconds at one point on the trigger point in upper trapezius, right after the dry needling application.

The placebo/control group will receive the DN application 1.5 cm away from the trigger point and will follow the application protocol described above. The LLLT equipment will be turned off during the intervention. As the other groups, it will be performed one session of the dry needling followed by the intervention with the laser turned off.

The present study is grounded on the ethical principles, with base on the Resolution no 466 of December 12th, 2012, of the National Health Council, which incorporates under the individual and collectivities optics, the four basic references of the bioethics: autonomy, non-maleficence, beneficence, and justice, among others, aiming to ensure the rights and duties which concern the scientific community, the research subjects, and the State.

Data analysis will be performed through the GraphPad Prisma® software, version 6.01 (GraphPad Software, La Jolla, California, USA). The Shapiro-Wilk test will be run to verify sample normality distribution. The Two-Way ANOVA test will be used for comparative analysis inter and intra-groups. The P value (p<0.05) will be used to establish the significance of the results, in addition to the 95% Confidence Interval (95% CI). The values will be described as a mean ± standard deviation.

Inclusion criteria

• Presence of active trigger point in upper trapezius.
• Use of computer for typing activities for, at least, 20 hours per week.
• Presence of mechanic pain in cervical region for less than three months.
• Pain level higher than 3 and lower than 8 on the Visual Analogue Scale (VAS) for neck and cervical regions in the last 30 days.

Exclusion criteria

• Body Mass Index (BMI) higher than 30
• Presence of whiplash injury or other cervical pathologies such as herniated disc and
• Thoracic Gorge Syndrome;
• Presence of contraindication to the treatment with low-level laser therapy or with dry needling
• Fear of needles
• To be receiving treatment for the pain in neck and/or shoulder regions
• Make use of analgesic drugs, anti-inflammatory and/or muscle relaxants and anticoagulant medications.