The gemellus inferior arises from the ischial tuberosity upper border (immediately above the quadratus femoris) and blends with the obturator internus tendon to insert on the greater trochanter. It is the inferior component of the triceps coxae. Its origin at the ischial tuberosity places it adjacent to the proximal hamstring origin — ischial tuberosity pathology must differentiate between proximal hamstring avulsion and gemellus inferior strain.
| Origin | Upper border of the ischial tuberosity |
|---|---|
| Insertion | Medial surface of the greater trochanter (with the obturator internus tendon and gemellus superior) |
| Nerve Supply | Branch of the nerve to quadratus femoris (L4, L5, S1) |
| Blood Supply | Inferior gluteal artery |
| Actions | Hip external rotation; Minor hip abduction |
|---|
Gemellus inferior strain is a component of the deep external hip rotator injuries in high-speed sports. Its origin on the ischial tuberosity overlaps with the proximal hamstring attachment, making MRI characterisation important to distinguish hamstring avulsion (requiring surgical repair) from gemellus inferior tear (managed conservatively).
Not independently palpable — assessed as part of the deep external hip rotator complex at the ischial tuberosity.
Gemellus inferior muscle injury at the ischial tuberosity distinguished from hamstring avulsion by MRI to guide management.
