This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Anatomy
The main action of muscle "Gamellius" is? 
Select and explain. 
A. Medial rotation of thigh, B. Lateral rotation of thigh, C. Gluteus maximus, D. Gluteus medius and minimus
B: Lateral rotation of thigh
Answer: B: Lateral rotation of thigh 
Explanation: Gemellus muscle laterally rotates the femur at the hip joint. Superior gemellus muscle: Attaches proximally at the ischial spine; distally, the muscle attaches on the greater trochanter of the femur. The nerve to the obturator internus and superior gemellus muscles (L5, S1, S2) innervates this muscle.Inferior gemellus muscle: Attaches proximally on the ischial spine; distally, the muscle attaches at the greater trochanter of the femur. The nerve to the inferior gemellus and quadratus femoris muscles (L4, L5, S1) innervates this muscle.