The term "musculus obturator internus" refers to a specific muscle located within the human body. More commonly known as the internal obturator muscle, it is one of the several muscles found in the pelvic region. Its name originates from the Latin words "musculus," meaning muscle, "obturator," referring to the obturator foramen that it passes through, and "internus," indicating its internal location.
The musculus obturator internus arises from the inner surface of the pubic bone and the surrounding connective tissue known as the obturator membrane. It then extends horizontally along the side wall of the pelvic cavity and attaches to the greater trochanter of the femur, the large bony prominence on the upper thigh bone.
Functionally, the musculus obturator internus primarily acts on the hip joint. Its main role is to help with the rotation and stabilization of the hip joint by externally rotating the thigh bone. Additionally, this muscle aids in abduction and adduction movements of the hip, contributing to the smooth coordination of leg movements.
In terms of its innervation, the musculus obturator internus receives signals from the nerves that originate from the sacral plexus, specifically the posterior division of the sacral nerves S2 to S4.
Overall, the musculus obturator internus plays a crucial role in the movement and stability of the hip joint, making it an essential component of the pelvic musculature.
