A role for abdominal muscle in menstrual cramps?

We developed a method of studying spontaneous cramping to identify neurological mechanisms responsible for referred pelvic pain, which could allow for clinical phenotyping of dysmenorrhea. By evaluating the relationship between abdominal muscle activity and spontaneous pain, we were able to provide evidence linking distinct abdominal muscle activity to reported spontaneous cramps in primary dysmenorrhea.  In contrast, women with chronic pelvic pain were less likely to have abdominal muscle activity preceding cramping pain, had widespread mechanical hypersensitivity and responded poorly to naproxen. The phenotyping methods described in this manuscript provide a strategy for characterizing nociceptive mechanisms in cyclical uterine pain and may ultimately predict treatment responsiveness. These results are published in the American Journal for Obstetrics and Gynecology.