While a patient is walking in the parallel bars, the physical therapist observes that the pelvis drops down on the side opposite the stance extremity. This gait deviation is an indication of weakness of the hip:

While a patient is walking in the parallel bars, the physical therapist observes that the pelvis drops down on the side opposite the stance extremity. This gait deviation is an indication of weakness of the hip:

• A. Abductors of the Swing Extremity
• B. Adductors of the Swing Extremity
• C. Abductors of the Stance Extremity
• D. Adductors of the Stance Extremity

Answer: (C)

The key idea is that hip abductors on the stance leg keep the pelvis level in the frontal plane during single-leg stance. When you step into stance, the stance-side gluteus medius and minimus contract to pull the pelvis upward on the opposite (swing) side, preventing it from dropping due to body weight. If those abductors are weak, gravity causes the pelvis to sag toward the swing side, producing a drop on the side opposite the stance leg. That contralateral pelvic drop is a classic sign of weakness in the hip abductors of the stance extremity. Abductors of the swing limb don’t produce this pattern, and weakness of the adductors (either leg) wouldn’t explain the pelvis dropping to the opposite side during stance.

The key idea is that hip abductors on the stance leg keep the pelvis level in the frontal plane during single-leg stance. When you step into stance, the stance-side gluteus medius and minimus contract to pull the pelvis upward on the opposite (swing) side, preventing it from dropping due to body weight. If those abductors are weak, gravity causes the pelvis to sag toward the swing side, producing a drop on the side opposite the stance leg. That contralateral pelvic drop is a classic sign of weakness in the hip abductors of the stance extremity. Abductors of the swing limb don’t produce this pattern, and weakness of the adductors (either leg) wouldn’t explain the pelvis dropping to the opposite side during stance.