obturator internus
noun
obturator in·ter·nus
| \ -in-ˈtər-nəs
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Medical Definition of obturator internus
: a muscle that arises from the margin of the obturator foramen and from the obturator membrane, that inserts into the greater trochanter of the femur by way of tendons passing through the greater sciatic foramen, and that acts to rotate the thigh laterally when it is extended and to abduct it in the flexed position