Which motions are associated with the posterior fibers of gluteus medius?

Which motions are associated with the posterior fibers of gluteus medius?

• A. Hip flexion and internal rotation
• B. Hip extension and external rotation
• C. Knee extension and toe extension
• D. Ankle plantarflexion and inversion

Answer: (B)

The posterior portion of the gluteus medius is aligned to pull the thigh backward and outward. When the hip extends, these fibers activate to draw the femur into extension, and their orientation from the posterior ilium to the greater trochanter creates a lateral, or external, rotation of the hip. So, the movements they produce are hip extension and external rotation. Other options describe actions at different joints or by different parts of the hip muscles. Hip flexion and internal rotation are driven by the anterior fibers, while knee or toe movements and ankle movements are not actions of the hip muscles.

The posterior portion of the gluteus medius is aligned to pull the thigh backward and outward. When the hip extends, these fibers activate to draw the femur into extension, and their orientation from the posterior ilium to the greater trochanter creates a lateral, or external, rotation of the hip. So, the movements they produce are hip extension and external rotation.

Other options describe actions at different joints or by different parts of the hip muscles. Hip flexion and internal rotation are driven by the anterior fibers, while knee or toe movements and ankle movements are not actions of the hip muscles.