The gemellus superior is the upper of the two gemellus muscles flanking the obturator internus tendon, originating from the ischial spine and inserting with the obturator internus on the greater trochanter. It is the smallest of the six deep external rotators. Together with the gemellus inferior it reinforces the obturator internus tendon mechanically, acting as accessory heads of the obturator internus to provide additional external rotation torque and posterior hip joint compression.
| Origin | Outer surface of the ischial spine |
|---|---|
| Insertion | Medial surface of the greater trochanter via the obturator internus tendon |
| Nerve Supply | Nerve to obturator internus (L5, S1) |
| Blood Supply | Inferior gluteal artery |
| Actions | External rotation of the hip; Stabilises the posterior hip capsule |
|---|
Its primary contribution is mechanical reinforcement of the obturator internus tendon as it turns the corner around the lesser sciatic notch, providing additional external rotation force and posterior capsule stabilisation.
The gemellus superior is rarely assessed in isolation clinically and is evaluated as part of the deep external rotator group. It is visible on MRI and can be involved in deep gluteal syndrome alongside the piriformis and obturator internus. The ischial spine, its origin, is palpated during pudendal nerve block and sacrospinous fixation procedures in gynaecological surgery.
Not directly palpable individually. Assessed as part of the deep external rotator group through resisted hip external rotation and passive internal rotation stretch testing.
Combined deep gluteal pain from the external rotator group including gemellus superior involvement, producing posterior hip pain reproduced by deep gluteal palpation and resisted external rotation.
