What is the role of anticipatory postural adjustments (APAs) in gait initiation?

• A. They occur after movement onset.
• B. They are unrelated to balance.
• C. They only occur during running.
• D. Planning and activation of muscles before movement onset to shift the COM and prepare for a stable start, reflecting anticipatory control.

Answer: (D)

Anticipatory postural adjustments are pre-m movement activations that prepare the body for the destabilizing effects of starting to walk. Before the first step, the nervous system primes muscles around the ankles and hips to shift the center of mass and move the center of pressure in just the right way. This forward and toward-the-stepping-leg shift creates the momentum and alignment needed for a stable start, so the upcoming step can be executed smoothly without losing balance. These adjustments are a form of anticipatory (feedforward) control, not reactive responses that happen after movement begins. They’re essential for gait initiation and apply to more than just running, reflecting how the body plans to maintain balance during movement onset.