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• The plantar reflex is important in identifying a UMN lesion , it is an objective response that can be compared by various observers.

• The outer edge of sole of the foot is stimulated by firmly scratching a key or stick along it from the heel towards the little toe.

• In healthy adults a slight stimulus also produce early contraction of the tensor fascia lata, often accompanied by a slighter contraction of adductors of the thigh and sartorious.

• With a slightly stronger stimulus flexion of four outer toes appears , which increases with with strength of the stimulus until all toes are flexed on the metatarsus and drawn together , the ankle beign slightly dorsiflexed and inverted. This is called flexor plantar response.

• This is called flexor plantar response.

• With still a strong stimuli withdrawal of all four limbs occurs.

• Babinski's extensor plantar response is pathologic of an UMN Lesion . Instead of normal flexor response , dorsiflexion of the great toe precedes all other movement .

• This is followed by spreading and extension of all other toes by marked dorsiflexion of the ankle and by flexion withdrawal of the hip and knee.

• With cotical spinal lesion the area from which the extensor plantar reflex can be elicited enlarges , spreading inwards and over the sole of the foot and then upwards along the leg to the knee or even higher.

• For this reason the extension of the great toe generally assosciated with dorsiflexion of the foot can sometimes can also be obtained by squeezing the calf or pressing heavily along the inner border of the tibia (Oppenheim's sign ) or by pinching the calcaneous tendon ( Gordon's reflex ).

• In infants under one year it is normal to have extensor response. The flexor response appears in the subsequent 6-12 months as myelination of the corticospinal pathways is completed.