The Immediate Effects of Dry Needling Acupuncture on Pain Intensity and Pressure Pain Threshold in Patients With Myofascial Pain Syndrome of the Upper Trapezius

Myofascial pain syndrome (MPS) is a regional pain condition involving muscles, fascia, and surrounding soft tissues and is commonly associated with myofascial trigger points (MTrPs). The upper trapezius muscle is a frequent site of MTrPs and may be associated with neck and shoulder pain, muscle stiffness, and functional limitations.

Dry needling is a minimally invasive acupuncture technique that uses a sterile filiform needle without the administration of pharmacological substances. The needle is inserted into the identified myofascial trigger point with the aim of providing mechanical stimulation and inducing a local twitch response. These effects may contribute to the reduction of MTrP irritability and pain through mechanical and neurophysiological mechanisms.

This study is designed as a quasi-experimental study using a one-group pretest-posttest design. The study will be conducted at the Medical Acupuncture Clinic of RSUPN Persahabatan, Jakarta, from August to December 2026. The study will include adult participants aged 18-59 years with posterior neck and shoulder pain, a myofascial trigger point in the upper trapezius muscle, a baseline Numeric Rating Scale (NRS) score of 4-6, and a Pressure Pain Threshold (PPT) of ≤3 kg.

Eligible participants who provide written informed consent will undergo a single session of dry needling. The intervention will be performed by a medical acupuncture resident of the Faculty of Medicine, Universitas Indonesia, with competency level 3. A sterile acupuncture needle measuring 0.25 × 40 mm will be inserted into the identified myofascial trigger point of the upper trapezius muscle at a 90-degree angle to the skin surface in the superior-inferior direction. Fast-in and fast-out needle manipulation will be performed for a maximum of three times or until one local twitch response occurs. The needle will then be immediately removed without retention.

Pain intensity and pressure pain threshold will be assessed immediately before the intervention and at 30 minutes, 24 hours, and 72 hours after the intervention. Pain intensity will be measured using the Numeric Rating Scale (NRS), ranging from 0 to 10, with higher scores indicating greater pain intensity. Pressure pain threshold will be measured using an algometer at the identified anatomical site, and the value will be recorded at the point when the participant first reports a sensation of pain.

The primary outcomes of interest are changes in NRS and PPT from baseline following the dry needling intervention. The study will evaluate changes at 30 minutes, 24 hours, and 72 hours after treatment.

Participants will also be monitored for adverse effects associated with the procedure. Following the intervention, participants will receive instructions regarding post-procedure care, including avoiding massage of the treated area and heavy shoulder loading, performing stretching exercises, maintaining ergonomic posture, and using a cold compress if discomfort occurs.

Data will be analyzed using SPSS version 25.0. Numerical variables will be assessed for normality using the Shapiro-Wilk test. For normally distributed paired data, the paired t-test will be used, while the Wilcoxon signed-rank test will be used for non-normally distributed data. Statistical significance will be defined as p \< 0.05.