The names "superior gemellus" and "inferior gemellus" are precisely from its relations with the obturator internus muscle (Llusa et al., 2004).
In this corpse, bilateral absence of superior gemellus muscle coexisted with unilateral absence of inferior gemellus muscle.
(2007) mentioned that the superior gemellus muscle can merge with the piriformis muscle or gluteus minimus muscle, and the inferior gemellus muscle can fuse with the quadratus femoris muscle.
obturator internus muscle tendon almost immediately forms after leaving the pelvis, joining the superior and inferior gemellus muscles.
After articular capsule and short external rotators (Including piriformis, superior gemellus, inferior gemellus
, quadratus femoris) were reattached to the posterior border of the greater trochanter by several bone holes after replacement, one of our researchers, who did not involve in the operation and in evaluation of the results, was responsible for opening these envelopes and preparing the study medication.
Measurement of left and right QF muscle CSA was performed on electronic imaging software, InteleViewer (Intelerad, Montreal, Canada), by manually tracing around the muscle borders of the four most cephalad slices that were inferior to obturator internus and inferior gemellus. These four slices were found to have the most distinct muscle borders and were clear despite variations in anatomy and size of the participants.
The transducer placement was adjusted until the most proximal image of QF with distinct borders was located inferior to obturator internus and inferior gemellus. The medium-sized curvilinear probe was required to ensure that bony landmarks, ischial tuberosity and the posterior border of the greater trochanter of the femur, were well defined in the image.
Caption: Figure 1 Quadratus femoris originates from the external border of the ischial tuberosity, inserts into the linea quadrata and is innervated by L5 and S1 nerves (4) (P, piriformis; SG, superior gemellus; OI, obturator internus; IG, inferior gemellus; OE, obturator externus; QF, quadratus femoris).
The thick line represents the most proximal of these images on MRI and was used for comparison with the single USI image (OI, obturator internus; IG, inferior gemellus; QF, quadratus femoris).