Which statement best describes the Trendelenburg test protocol?

Which statement best describes the Trendelenburg test protocol?

• A. Patient stands on one leg with opposite hip flexed 30°, maintain stance 30 seconds; observe pelvis from front and back.
• B. Patient stands on both legs and performs pelvic tilt.
• C. Patient lies on side with bottom leg flexed (Ober's test).
• D. Patient sits with knees bent and feet flat.

Answer: (A)

The main idea being tested is how the Trendelenburg test assesses the strength of the hip abductors, especially the gluteus medius, to stabilize the pelvis during single-leg stance. In a normal result, the pelvis stays level when standing on one leg. If the stance-side hip abductors are weak, the pelvis drops on the opposite (unsupported) side, which is the positive sign people look for. The described protocol—standing on one leg and monitoring the pelvis from front and back, with the added detail of the opposite hip flexion and a set stance time—fits this purpose directly because it requires the pelvis to stay level during unilateral loading. The other options don’t measure this single-leg pelvic stability: standing on both legs and tilting the pelvis doesn’t test unilateral abductor strength; Ober’s test (lying on the side with the bottom leg flexed) is used to assess iliotibial band tightness, not hip abductor strength; a seated position with knees bent does not probe the pelvis during single-leg stance.

The main idea being tested is how the Trendelenburg test assesses the strength of the hip abductors, especially the gluteus medius, to stabilize the pelvis during single-leg stance. In a normal result, the pelvis stays level when standing on one leg. If the stance-side hip abductors are weak, the pelvis drops on the opposite (unsupported) side, which is the positive sign people look for. The described protocol—standing on one leg and monitoring the pelvis from front and back, with the added detail of the opposite hip flexion and a set stance time—fits this purpose directly because it requires the pelvis to stay level during unilateral loading.

The other options don’t measure this single-leg pelvic stability: standing on both legs and tilting the pelvis doesn’t test unilateral abductor strength; Ober’s test (lying on the side with the bottom leg flexed) is used to assess iliotibial band tightness, not hip abductor strength; a seated position with knees bent does not probe the pelvis during single-leg stance.