Hoover’s sign may be used to help differentiate organic from functional hemiplegia or monoplegia. It is based on the fact that when a recumbent patient attempts to lift one leg, downward pressure is felt under the heel of the other leg, hip extension being a normal synergistic or synkinetic movement. The finding of this synkinetic movement, detected when the heel of the supposedly paralyzed leg presses down on the examiner’s palm, constitutes Hoover’s sign: no increase in pressure is felt beneath the heel of a paralyzed leg in an organic hemiplegia.
In addition, the synkinetic hip extension movement is accentuated when attempting to raise a contralateral paretic leg, whereas in functional weakness it is abolished.
Stone J, Sharpe M. Hoover’s sign. Practical Neurology 2001; 1: 50-53