The superior gemellus muscle originates in the external face and in the inferior margin of the ischial spine, while the inferior gemellus muscle originates from the ischial tuberosity (Testut & Latarjet, 1975).
There are reports in the literature describing bilateral absense of superior gemellus muscle (Terry; Bajka et al., 2004; Fernandes et al., 2013).
Wood (1867) reported bilateral absence of the superior gemellus muscle in 4.28 % of samples (3 of 102 corpses).
(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.
In the study of Shinohara, in most cases, the superior gemellus muscle received a double innervation from quadratus femoris muscle nerve and obturator internus muscle nerve (12 of 14 corpses).
Terry, related the absence of the superior gemellus muscle with a decrease in the size of the ischial spine, which is not possible to verify in this case because the muscle was absent on both sides.
Bilateral absence of superior gemellus muscle in elderly cadaver.