THE PLANTAR REFLEX - RePub

5. If dorsiflexion of the great toe is mechanically favoured (pes cavus,
paralysis of short toe flexors), this only means that voluntary upward
movements are more likely to interfere, and not that a possible Babinski
reflex is false.
6. To decide whether an upward movement of the great toe is a Babinski
sign, there are three step-wise criteria:
( 1) action of the extensor hallucis longus muscle,
(2) simultaneous contraction of other (physiological) flexor muscles,
(3) exclusion of voluntary movements.
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