Reactive postural muscle activation is based on which type of control?

• A. Feedforward control
• B. Predictive control
• C. Open-loop control
• D. Feedback control

Answer: (D)

Reactive postural muscle activation rests on feedback control. When a disturbance knocks your balance, your sensory systems—proprioceptive, vestibular, and visual—detect the change in position and movement and send error signals to the nervous system. In response, the brain adjusts muscle commands in real time to counter the deviation and bring the body back toward stability. This reactive correction hinges on processing actual sensory feedback from the perturbation, which is the hallmark of feedback control.

In contrast, anticipatory or predictive control involves preparing for expected disturbances before they occur, using prior information to shape muscle activity in advance. Open-loop control would execute a pre-set motor pattern without relying on ongoing feedback to correct errors, which isn’t sufficient for maintaining balance when disturbances are unpredictable.