Which statement about the Trendelenburg sign is true?

Which statement about the Trendelenburg sign is true?

• A. It indicates weakness of the gluteus medius
• B. It indicates tight iliopsoas
• C. It indicates laxity of the hip joint
• D. It indicates overactivity of the gluteus maximus

Answer: (B)

The Trendelenburg sign tests hip abductor strength, especially gluteus medius and minimus. When you stand on one leg, these muscles contract to keep the pelvis level in the frontal plane. If they’re weak, the pelvis drops on the opposite side, producing a positive sign. This weakness points to the abductors rather than tightness of the iliopsoas, hip joint laxity, or overactivity of gluteus maximus, which don’t cause the characteristic pelvic drop during single-leg stance.

The Trendelenburg sign tests hip abductor strength, especially gluteus medius and minimus. When you stand on one leg, these muscles contract to keep the pelvis level in the frontal plane. If they’re weak, the pelvis drops on the opposite side, producing a positive sign. This weakness points to the abductors rather than tightness of the iliopsoas, hip joint laxity, or overactivity of gluteus maximus, which don’t cause the characteristic pelvic drop during single-leg stance.