Which muscles are prime movers for hip internal rotation?

Which muscles are prime movers for hip internal rotation?

• A. Gluteus medius (anterior fibers), Gluteus minimus, & Tensor fasciae latae
• B. Gluteus maximus
• C. Piriformis
• D. Obturator externus

Answer: (A)

Internal rotation of the hip is driven by muscles whose fibers pull the femur toward the midline when they cross the joint from the anterior aspect. The anterior fibers of the gluteus medius and the gluteus minimus are positioned to rotate the thigh inward, especially as the hip flexes or is in a neutral position. The tensor fasciae latae also helps medially rotate the femur because its tendon runs down the lateral thigh and, with the hip flexed, its pull on the femur contributes to inward rotation. In contrast, the gluteus maximus is mainly a hip extensor and external rotator, pulling the thigh outward. Piriformis and obturator externus are primarily external rotators (they rotate the thigh laterally), though some of these muscles can contribute to different actions depending on hip position, they are not the primary internal rotators. So the combination of gluteus medius (anterior fibers), gluteus minimus, and tensor fasciae latae best represents the prime movers for hip internal rotation because of their anterior lines of pull that medially rotate the femur.

Internal rotation of the hip is driven by muscles whose fibers pull the femur toward the midline when they cross the joint from the anterior aspect. The anterior fibers of the gluteus medius and the gluteus minimus are positioned to rotate the thigh inward, especially as the hip flexes or is in a neutral position. The tensor fasciae latae also helps medially rotate the femur because its tendon runs down the lateral thigh and, with the hip flexed, its pull on the femur contributes to inward rotation.

In contrast, the gluteus maximus is mainly a hip extensor and external rotator, pulling the thigh outward. Piriformis and obturator externus are primarily external rotators (they rotate the thigh laterally), though some of these muscles can contribute to different actions depending on hip position, they are not the primary internal rotators.

So the combination of gluteus medius (anterior fibers), gluteus minimus, and tensor fasciae latae best represents the prime movers for hip internal rotation because of their anterior lines of pull that medially rotate the femur.