Chronic thoracic (mid-back) pain can be difficult to treat, and there is limited evidence to guide the use of injection therapies for pain arising from muscles and surrounding soft tissues. Two commonly used treatments are trigger point injections (TPI) and erector spinae plane (ESP) blocks, but no studies have directly compared their effectiveness for chronic thoracic myofascial pain. The purpose of this study is to compare pain relief, physical function, emotional well-being, patient satisfaction, and safety following treatment with either an ESP block or TPI. Participants will be randomly assigned to receive one of the two treatments. Researchers will follow participants for up to 12 weeks after the procedure and collect information through questionnaires and pain assessments.