The plantar reflex (PR) is one of the most important reflex in the body. It is basically a polysynaptic superficial reflex, designed to withdraw the stimulated part, i.e., the foot from a potentially dangerous stimulus
Joseph Babinski, a French neurologist, first differentiated between a normal and a pathologic plantar response and he described the Babinski sign in 1896. The Babinski’s sign is observed in patients with pyramidal tract dysfunction and is characterised by a dorsiflexion or extension ofthe the ankle and flexion of the hip and knee joint and slight abduction of the thigh,
leading to a withdrawal of the leg on plantar stimulation
False Babinski sign may sometimes occur in the absence of pyramidal tract lesion. This may be seen in the following conditions.
- A voluntary withdrawal in overtly sensitive individuals on attempting to stroke the sole of the foot.
- As a response in plantar hyperesthesia
- Application of a strong or painful stimulus to the sole of the foot.
- In the presence of chorea, where the big toe may extend as a response to dystonic posturing.
- If the short flexors of the toes are paralyzed (due to lower motor neuron lesion), there may be an inversion of the plantar reflex.
- Contraction of hamstring muscles can be felt in Babinski sign. There is no associated contraction of the hamstring muscles in pseudo babinski
- Pressure on the base of the great toe while eliciting the plantar reflex does not inhibit the extensor in Babinski sign.Pressure on the base of the great toe while eliciting the plantar response will inhibit the withdrawal extensor response
