Patients and methods: Between July 2022 and December 2022, a total of 70 patients (8 males, 62 females; mean age: 38.8±11.1 years; range, 18 to 61 years) with MPS in the upper and/or middle trapezius muscle were included in this prospective, randomized clinical study. The patients were randomly divided into two groups as the MDI group (n=35) and the ESWT group (n=35). The first group received MDI with 5% dextrose, while the second group received radial ESWT. Both groups received three sessions of treatment with one-week intervals. An exercise program was provided for all patients. Both groups were assessed using the Visual Analog Scale (VAS) for activity-related pain, Pressure Pain Threshold (PPT), Neck Disability Index (NDI), and Nottingham Health Profile (NHP) at baseline (pre-treatment), and at Weeks 2 and 4 (post-treatment).

Results: Following treatment, both groups exhibited significant improvements in VAS, PPT, NDI, and NHP scores (p<0.001). However, the MDI group demonstrated a higher improvement in the VAS scores at both Weeks 2 and 4 (p<0.001). The NDI scores were significantly more favorable in the MDI group at Weeks 2 and 4 (p=0.044 and p=0.011, respectively). In terms of PPT and NHP scores, the MDI group showed a significantly greater improvement at Week 4 (p=0.005 and p=0.013, respectively).

Conclusion: Both MDI and ESWT treatments have positive effects on pain and functionality in MPS patients, while MDI seems to yield more favorable results compared to ESWT. Keywords : Dextrose, extracorporeal shockwave therapy, injection, myofascial pain syndrome, neck pain, pain threshold