What is feedback control in the context of posture?

• A. Postural control in response to sensory feedback from external perturbation
• B. Postural adjustments based on future predictions
• C. Voluntary movement with no sensory input
• D. Control relying on visual input only

Answer: (A)

Feedback control in posture relies on real-time sensory information to keep you upright. When a perturbation displaces your body, sensors in the muscles, joints, inner ear, and eyes provide data on position and movement. The brain compares this actual state to the intended upright posture and quickly generates corrective muscle commands to reduce the error, forming a closed-loop adjustment that happens after the disturbance. This continuous loop uses multiple senses—proprioception, vestibular input, and vision—to maintain balance, not just one source. Anticipating a disturbance uses feedforward control, which is different from feedback that responds to what’s currently sensed. Relying on vision alone isn’t sufficient either, since posture depends on the integration of several sensory signals, especially when vision is limited or unavailable.