During Trendelenburg assessment, a pelvic drop on the unsupported side indicates weakness of which muscle group?

• A. Pelvic drop on the supported side.
• B. Pelvic drop on the unsupported side.
• C. Pelvic elevation on the unsupported side.
• D. Symmetric pelvis during stance.

Answer: (B)

A Trendelenburg sign tests the strength of the hip abductors (gluteus medius and minimus) on the leg you’re standing on. These muscles pull the pelvis level as you balance on one leg. If they’re weak, gravity causes the pelvis to dip toward the opposite (unsupported) side, so a pelvic drop on the unsupported side indicates weakness of the hip abductors on the stance leg.