On foam or compliant surfaces, proprioceptive input is reduced and which balance strategies become more prominent?

• A. Ankle strategy
• B. Hip or stepping strategies
• C. Visual tracking strategy
• D. Cognitive strategy

Answer: (B)

When the feet and ankles provide less proprioceptive information on foam or a compliant surface, the body can’t rely on small, ankle-based corrections. The ankle strategy, which rotates the body about the ankles to keep the center of mass over the base of support, becomes less effective because the unstable surface dampens those precise ankle movements. Instead, balance control shifts to the hip strategy, engaging the hip and trunk muscles to reorient the pelvis and upper body and bring the center of mass back over the base of support. If the perturbation is still too large or the surface too unstable, taking a step to widen the base of support is used, making stepping strategies more prominent. Visual tracking can help but doesn’t replace the mechanical adjustments, and cognitive strategies rely on conscious attention and are not the primary automatic responses in these situations.