Trigger point injections (TPI) is most conventional methods of treatment for myofascial pain syndrome (MPS). But recently, there have been many researches about extra –corporeal shockwave treatment (ESWT) which has proven to be just as effective in decreasing pain with advantage of being non-invasive. Psoas muscle, located in retroperitoneal space, is risky place for TPI owing to its location. We report a case of a patient who visited our hospital with lower abdominal and back pain. The diagnosis of psoas MPS was made after failure of TPI into rectus abdominis, which we successfully treated with ESWT. Psoas MPS could go undiagnosed in patients presenting with abdominal pain. Conventional invasive therapy such as TPI is dangerous in this case as a consequence of profound location in peritoneal cavity. ESWT may be the safe and effective therapeutic option for psoas MPS. (Clinical Pain 2017;16:99-101)

KeywordsMyofascial pain syndrome, Psoas, Extra-corporeal shock wave treatment