| Latin | Musculus obturatorius internus |
|---|---|
| Origin |
|
| Insertion |
|
| Action |
|
| Nerve | Nerve to obturator internus (L5–S2) |
| Group | Deep hip rotators |
Palpation
- Client prone with a bolster under the ankles; stand beside the hip.
- Find the greater trochanter and the ischial tuberosity. The outside part of the tendon crosses the space between them, above quadratus femoris, under gluteus maximus.
- Sink in slowly with flat fingers. You cannot feel it apart from the gemelli; the part inside the pelvis cannot be reached in a massage.
- Bend the client's knee to 90° and ask them to press the foot inwards against light resistance (hip lateral rotation); feel the deep tissue tighten.
The obturator internus is unusual: it starts inside the pelvis, on the inner side of the obturator membrane (a sheet of tissue that closes over the large hole in the front of the hip bone). Its tendon leaves the pelvis through a small opening (the lesser sciatic foramen), bends at a right angle around the back of the ischium, and then runs across the back of the hip joint to the Greater trochanter.
Only the part outside the pelvis matters for massage, and even that lies deep under Gluteus maximus. It sits between the two Gemelli, which blend into its tendon, with Piriformis above and Quadratus femoris below. The sciatic nerve passes over the back of it, so use slow, broad pressure and ask the client to report any tingling or pain spreading down the leg. Treat it as part of the Deep hip rotators as a group.
Do not confuse it with Obturator externus. The names mean “inner” and “outer”: obturator internus covers the inside of the obturator membrane, and obturator externus covers the outside, at the front of the pelvis. They have different nerves, too. The Wikipedia infobox also lists abduction of the extended hip; the article text, used above, gives abduction only when the hip is flexed.