Which hip muscle is a prime mover for internal rotation?

Which hip muscle is a prime mover for internal rotation?

• A. Piriformis
• B. Gluteus Minimus
• C. Tensor Fasciae Latae
• D. Gluteus Maximus

Answer: (B)

Internal rotation of the hip involves turning the thigh inward toward the midline. The muscle most effective at driving that motion is the gluteus minimus. Its fibers run from the ilium to the anterior aspect of the greater trochanter, so when it contracts, it pulls the femur medially. This makes gluteus minimus a primary internal rotator, especially when the hip is flexed. Piriformis, while a rotator of the hip, is mainly an external rotator when the leg is extended and only assists in other roles when the hip is flexed; tensor fasciae latae contributes to medial rotation mainly as a synergist and stabilizer rather than the primary mover; gluteus maximus is a powerful extensor and external rotator, not an internal rotator. Therefore, gluteus minimus best fits the role of a prime mover for internal rotation.

Internal rotation of the hip involves turning the thigh inward toward the midline. The muscle most effective at driving that motion is the gluteus minimus. Its fibers run from the ilium to the anterior aspect of the greater trochanter, so when it contracts, it pulls the femur medially. This makes gluteus minimus a primary internal rotator, especially when the hip is flexed.

Piriformis, while a rotator of the hip, is mainly an external rotator when the leg is extended and only assists in other roles when the hip is flexed; tensor fasciae latae contributes to medial rotation mainly as a synergist and stabilizer rather than the primary mover; gluteus maximus is a powerful extensor and external rotator, not an internal rotator. Therefore, gluteus minimus best fits the role of a prime mover for internal rotation.