Inferior Gemellus Muscle
Overview
| Muscle | Origin | Insertion | Innervation | Action |
|---|---|---|---|---|
| Inferior Gemellus | Ischial tuberosity | Medial surface of greater trochanter via obturator internus tendon | Nerve to Quadratus femoris L5 - S1 |
Hip: ER, Extension, Abduction |
Origin
Ischial tuberosity
Insertion
Joins obturator internus tendon to medial surface of greater trochanter
Innervation
Action
- Hip: Extension, ER, and Stabilization
- (also active in abduction, depending on the joint’s position)
Notes
“The gemellus superior and inferior (from the Latin root geminus, meaning twins) are two, small, nearly identically sized muscles with proximal attachments on either side of the lesser sciatic notch (see Fig. 12.43). Each muscle blends in with the central tendon of the obturator internus for a common attachment to the femur. Immediately below the gemellus inferior is the quadratus femoris muscle. This flat muscle arises from the external side of the ischial tuberosity and inserts on the posterior side of the proximal femur. In cases of abnormal bony morphology, this muscle may become impinged between the lesser trochanter and ischium, typically during motions that involve the extremes of external rotation.212 If chronic and repetitive, this clinically termed “ischiofemoral impingement” may cause groin and buttock pain along with abnormal MR signaling from the qua dratus femoris muscle”2