What action does the iliacus perform at the hip?

What action does the iliacus perform at the hip?

• A. Internal rotation and abduction
• B. Flexion and lateral rotation of thigh at hip
• C. Extension
• D. Adduction

Answer: (B)

Hip flexion is the primary job of the iliacus, acting as part of the iliopsoas to pull the femur forward at the hip. When the thigh is flexed, its fibers also contribute to external (lateral) rotation due to their oblique orientation across the joint. It does not extend the hip, nor does it abduct or adduct the thigh, which are actions favored by other muscle groups. So the iliacus produces flexion of the thigh at the hip and can assist with external rotation when the thigh is flexed.

Hip flexion is the primary job of the iliacus, acting as part of the iliopsoas to pull the femur forward at the hip. When the thigh is flexed, its fibers also contribute to external (lateral) rotation due to their oblique orientation across the joint. It does not extend the hip, nor does it abduct or adduct the thigh, which are actions favored by other muscle groups. So the iliacus produces flexion of the thigh at the hip and can assist with external rotation when the thigh is flexed.