Which action does the superior gemellus perform on a flexed thigh?

Which action does the superior gemellus perform on a flexed thigh?

• A. Abducts a flexed thigh
• B. Laterally rotates an extended thigh
• C. Abducts the thigh while extended
• D. Extends the thigh

Answer: (A)

The action depends on the position of the hip. The superior gemellus is one of the deep external rotators of the hip, and its line of pull gives it two related roles: when the thigh is flexed, it helps abduct the femur; when the thigh is extended, it primarily contributes to lateral rotation. In the scenario of a flexed thigh, its function to move the thigh away from the midline (abduction) is the correct and most specific action. The other options describe actions that occur with the thigh in a different position (extended) or are not the primary action of this muscle, so they don’t fit the given condition.

The action depends on the position of the hip. The superior gemellus is one of the deep external rotators of the hip, and its line of pull gives it two related roles: when the thigh is flexed, it helps abduct the femur; when the thigh is extended, it primarily contributes to lateral rotation. In the scenario of a flexed thigh, its function to move the thigh away from the midline (abduction) is the correct and most specific action. The other options describe actions that occur with the thigh in a different position (extended) or are not the primary action of this muscle, so they don’t fit the given condition.