Comparison of the Effectiveness of Dry Needling Versus the Combination of Dry Needling and Local Anesthetic Injection in Myofascial Pain Syndrome of the Upper Trapezius Muscle: A Sham-Controlled, Randomized Clinical Trial

Overview

This study was designed to compare the effectiveness of three different treatment protocols in patients diagnosed with myofascial pain syndrome of the upper trapezius muscle. A total of 90 volunteers aged between 18 and 65 years, with active trigger points identified in the upper trapezius muscle, will be included in the study. Participants will be randomly assigned to three groups: * Group 1: Dry needling and stretching exercises * Group 2: Dry needling following local anesthetic injection with 1% lidocaine and stretching exercises * Group 3 (Control): Sham dry needling following local anesthetic injection with 1% lidocaine and stretching exercises In all groups, treatment sessions will be administered at weeks 0, 1, 2, and 3; and participants will undergo clinical assessments at baseline (pre-treatment), at the end of treatment, one month after treatment completion, and three months after treatment completion. The primary outcome will be pain severity, measured using the Numeric Pain Rating Scale (NRS); secondary outcomes will include functional status evaluated with the Neck Pain and Disability Scale (NPADS) and QuickDASH, and muscle tenderness assessed by pressure pain threshold (PPT) measurement. The findings are expected to contribute scientifically to clinical practice by identifying the most effective treatment combination for managing upper trapezius myofascial pain syndrome.

Myofascial pain syndrome (MPS) is one of the most common causes of chronic pain among musculoskeletal disorders, leading to both individual workforce loss and a decrease in quality of life. The pathophysiological basis of MPS consists of hyperalgesic areas within the muscle tissue, known as "trigger points. These trigger points usually arise due to repetitive microtrauma, poor posture, or static muscle use, with the upper trapezius muscle being one of the most frequently affected muscle groups . Dry needling (DN) induces local microtrauma within the muscle by directly and invasively stimulating the trigger points, thereby initiating local inflammation and achieving an analgesic effect. DN is thought to work by reducing muscle spasm, increasing oxygenation, and providing segmental pain inhibition \\\[1, 5\]. On the other hand, local anesthetic injection (LAI), particularly with agents such as lidocaine, provides rapid analgesia by temporarily blocking nerve conduction when applied directly around the trigger point . Although the combined use of DN and LAI has gained attention in recent years, comparative clinical data regarding their efficacy remain limited. Some studies in the literature have shown that LAI is more effective than DN in reducing pain , yet systematic data on the advantages of combined protocols are insufficient. Additionally, some randomized controlled trials have reported that DN provides functional improvement, while achieving similar pain scores compared to LAI. The use of sham procedures is critically important for evaluating the true biological effect of treatment. Especially in invasive techniques like dry needling, the absence of placebo control increases the risk of misinterpreting the analgesic effect. Therefore, there is a need for methodologically robust study designs. The present study aims to demonstrate the clinical superiority of combining DN with LAI, compared to DN alone and sham groups, in terms of both pain reduction and functional improvement. The combined approach may result in more lasting outcomes on muscle tension and function. Moreover, thanks to the comparison group with sham procedures, the true clinical efficacy of the interventions can be evaluated more objectively.