Theory 69/Balance/Ratio lens
Sway Is Noise Against Stiffness
The claim
Postural sway amplitude is set by the ratio of sensory noise to ankle stiffness, so a person with noisy proprioception sways more at the same strength.
01Mechanism
Balance is a feedback loop; noise drives sway while stiffness restores position, and the ratio sets the equilibrium amplitude.
02Prediction
Sway should track the ratio.
03Refutation
Sway tracking muscle strength would remove noise.