Hip motion in the frontal plane helps reduce what during gait?

Hip motion in the frontal plane helps reduce what during gait?

• A. Vertical displacement of the body's center of mass
• B. All ankle motion
• C. Hip extension torque
• D. Swing limb advancement

Answer: (A)

Frontal plane hip control stabilizes the pelvis to smooth the vertical path of the body's center of mass during gait. When one leg is in stance, the hip abductors on that leg keep the pelvis level and prevent the opposite side from dropping. This pelvic stabilization reduces the up-and-down movement of the center of mass, making gait more efficient and stable. Other options don’t fit as directly. Ankle motion is driven by movements in other planes and joints, not primarily by frontal plane hip motion. Hip extension torque is a sagittal-plane action related to propulsive push-off, not pelvis stabilization in the frontal plane. Swing limb advancement relies mainly on hip flexion and knee/ankle actions, not on frontal plane hip motion.

Frontal plane hip control stabilizes the pelvis to smooth the vertical path of the body's center of mass during gait. When one leg is in stance, the hip abductors on that leg keep the pelvis level and prevent the opposite side from dropping. This pelvic stabilization reduces the up-and-down movement of the center of mass, making gait more efficient and stable.

Other options don’t fit as directly. Ankle motion is driven by movements in other planes and joints, not primarily by frontal plane hip motion. Hip extension torque is a sagittal-plane action related to propulsive push-off, not pelvis stabilization in the frontal plane. Swing limb advancement relies mainly on hip flexion and knee/ankle actions, not on frontal plane hip motion.