During the Clinical Test for Sensory Integration and Balance, increased sway on foam with eyes closed and with vision obscured by a dome indicates an inability to use which input for postural control?

• A. Vestibular input
• B. Somatosensory input
• C. Visual input
• D. Proprioceptive input

Answer: (A)

In this setup, the body is forced to rely on vestibular information to keep balance. The foam surface disrupts somatosensory and proprioceptive cues from the feet and ankles, and closing the eyes or obscuring vision removes visual input. With both visual and somatosensory cues unreliable, the only remaining source for postural control is the vestibular system, which detects head movements and orientation relative to gravity. If sway increases under these conditions, it indicates difficulty using vestibular input for balance. The other inputs aren’t usable here because foam renders somatosensory/proprioceptive feedback less reliable, and vision is blocked.