The goal of this study is to evaluate imaging biomarkers for quantitative assessments of myofascial pain and determine their ability to monitor treatment response and predict clinical outcomes.

This Phase 2 randomized clinical trial builds upon findings from Phase 1, which identified candidate imaging biomarkers of myofascial pain. The study will assess whether these biomarkers can monitor responses to local chemical injection treatment and predict clinical outcomes.

Participants with neck/shoulder pain and the presence of active myofascial trigger points will be referred from pain management clinics or recruited through the Volunteer for Health office. Eligible participants will undergo multi-modal imaging procedures, including magnetic resonance imaging (MRI), surface electromyography (sEMG), and fiber-optic imaging. Participants will then be randomized to receive either chemical injection or dry needling at the identified trigger points.

Over the course of two study visits, spaced approximately two weeks apart, participants will complete imaging procedures and patient-reported outcome questionnaires. The study team will analyze imaging and clinical data to evaluate the capacity of identified biomarkers to detect treatment-related changes and to predict longer-term clinical response.

Inclusion Criteria:

1. Adults between the ages of 18 and 80 years old.
2. History of spontaneous (non-provoked) pain in the neck and/or shoulder region lasting at least 3 months. Neck and/or shoulder pain, unilateral or bilateral.
3. Presence of a palpable myofascial trigger point (MTrP) in one or both upper trapezius muscles.
4. The participant has a Numeric Pain Rating Scale of 4/10 or more in the last one week, and the pain is reproducible by palpating the trigger point.
5. Pain localized to the area of the trigger point that is reproduced or worsened upon palpation.
6. Radiation of pain to the head, neck, or face with palpation is allowed but not required.

Exclusion Criteria:

1. Age <18 or >80 years old.
2. Acute cervical spine pathology, trauma (e.g. whiplash) or cervical radiculopathy
3. History of surgery involving the head, neck, or shoulder girdle.
4. Presence of neuromuscular pathologies or inflammatory muscle diseases (e.g. dermatomyositis)
5. Systemic disease with diffuse body pain (e.g. system lupus erythematosus)
6. Peripheral neuropathy
7. Cancer-related pain
8. Pregnancy, coagulopathy or other bleeding disorder, fever, general/local infection at the pain site, substance abuse, or any other diseases that may account for signs and symptoms mimicking myofascial pain.
9. Contraindication to MRI
10. Chronic fatigue syndrome, fibromyalgia, or chronic Lyme disease.
11. Use of acupuncture or changes in pain medications within 6 weeks of enrollment.
12. Receipt of Botox injection to the neck/shoulder region within the past 3 months or trigger point injection within the past 6 weeks.