Obturator internus bursitis: a common factor in low back pain.

The presence of irritation of the obturator internus bursa (OIB) is identified as a common but thus far overlooked focus of myofascial irritability in association with low back pain. Eighteen of 50 consecutive patients with low back pain (36%) demonstrated the presence of tenderness at the anatomical site of the OIB. OIB was found in 11% of men and 43% of women. Nineteen of the 50 patients had regional myofascial pain; of these, eight (42%) had OIB tenderness. Palpation of the OIB will commonly reveal local tenderness in patients suffering from low back pain. In these patients, conservative treatment of regional myofascial disorders may be made more effective when therapy and/or local steroid injections are appropriately directed to the obturator internus bursa.