Hip strategies are typically observed under which conditions?

• A. Small perturbations on stable surfaces
• B. Quiet standing with eyes closed
• C. Fast walking on level ground
• D. Larger perturbations on unstable surfaces

Answer: (D)

Hip strategies come into play when perturbations to balance are too large for the ankles to handle or when the surface is unstable. In these situations the body uses more proximal control, moving the hips and trunk to generate bigger corrective moments and reorient the upper body so the center of mass stays over the base of support. On unstable or compliant surfaces, ankle-only responses are less effective, so the hip joints are engaged to restore stability quickly. This is why larger disturbances on an unstable surface reliably evoke hip strategy responses. Smaller perturbations on a firm surface are typically managed by ankle movements, and dynamic tasks like fast walking involve gait-specific balance control rather than a perturbation-posed hip strategy in standing.