Babinski Reflex: What It Is, Normal vs Positive Sign and Test

Medically Reviewed By Dr. Ravikant Kumar, D.M , M.D , M.B.B.S, Associate Consultant - Neurosciences

Updated on: Oct 09, 2026
Published on: Sep 24, 2026

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Few clinical tests are as simple, fast and neurologically informative as the Babinski reflex. Running a blunt object along the outer edge of the sole produces a toe movement and the direction of that movement tells a neurologist a great deal about the integrity of the motor pathways between the brain and the spinal cord. The Babinski reflex is a routine part of the neurological examination across all ages. Because stroke, spinal cord injury and conditions affecting the upper motor neuron pathway are common neurological conditions, correctly interpreting the Babinski sign can significantly influence the speed and accuracy of clinical diagnosis.

What Is the Babinski Reflex

The Babinski reflex is a plantar reflex response first described by Joseph Babinski in 1896. It is elicited by stroking the outer edge (lateral border) of the sole of the foot from the heel toward the little toe and curving inward across the ball of the foot.

In a neurologically intact adult, this stimulus produces a downward curling (plantarflexion) of all the toes.

In infants under approximately 12 to 18 months of age and in adults with damage or dysfunction of the corticospinal (pyramidal) tract, the same stimulus produces the opposite response: the big toe extends upward (dorsiflexion) and the other toes fan outward. This is the positive Babinski sign, also called the extensor plantar response.

How the Babinski Reflex Test Is Performed

The Babinski test requires no equipment beyond a blunt-ended instrument.

The patient lies supine with the leg relaxed and the foot in a neutral position. Tension or ticklishness in the foot can alter the response.
The examiner holds the patient's ankle gently and applies a firm but not painful stroke along the outer edge of the sole, beginning at the heel and moving toward the little toe, then sweeping inward across the ball of the foot toward the base of the big toe. The stroke is applied using the handle of a reflex hammer, a tongue depressor, a key or the examiner's thumbnail.
The examiner observes the movement of the toes. A downward curling of the toes (plantarflexion) is the normal adult response. An upward extension of the big toe with or without fanning of the other toes (the Babinski sign) is the abnormal adult response.
The test is performed on both feet. An asymmetric result (positive on one side, negative on the other) suggests a unilateral lesion of the corticospinal tract on the side of the positive response.

Babinski Reflex in Newborns: Is It Normal

A positive Babinski sign is entirely normal in newborns and infants up to approximately 12 to 18 months of age. In some infants this response persists until 24 months of age, which is still considered within the normal developmental range.

The Babinski reflex is a standard part of the neonatal and infant examination. Its persistence beyond 24 months of age may warrant paediatric neurology review.

Positive Babinski Sign: What It Means

In a child over approximately two years or in an adult, a positive Babinski sign is abnormal. It indicates damage or dysfunction of the upper motor neuron pathway, specifically the corticospinal (pyramidal) tract. This tract originates in the motor cortex, passes through the internal capsule and brainstem, crosses to the opposite side at the level of the medulla (the decussation of the pyramids) and continues down the spinal cord to synapse on lower motor neurons.

A positive Babinski sign tells the doctor that somewhere along this corticospinal pathway there is a lesion, but it does not identify the location or cause. That requires the full neurological examination, clinical history and in most cases neuroimaging (MRI or CT of the brain and spine).

A positive Babinski sign can be transient (postictal or during deep sleep or anaesthesia) or persistent (as in a structural lesion of the brain or spinal cord). A bilateral positive Babinski sign suggests a bilateral corticospinal tract lesion whereas a unilateral positive sign suggests a lesion on the same side as the positive response.

Causes of a Positive Babinski Sign in Adults

A persistent positive Babinski sign in an adult indicates upper motor neuron dysfunction. The most clinically important causes are listed below.

Stroke (cerebrovascular accident): Ischaemic or haemorrhagic stroke involving the motor cortex, internal capsule or corticospinal tract produces a contralateral positive Babinski sign along with hemiplegia or hemiparesis.
Spinal cord injury or compression: Trauma, disc herniation, spinal cord tumour, spondylotic myelopathy or epidural abscess can compress or injure the corticospinal tract, producing a bilateral positive Babinski sign below the level of the lesion.
Multiple sclerosis (MS): MS causes demyelinating lesions at multiple sites within the central nervous system, frequently involving the corticospinal tract. A positive Babinski sign is a common finding in MS.
Brain tumour (primary or metastatic): A tumour affecting the motor cortex or the corticospinal tract can produce a positive Babinski sign typically along with progressive hemiparesis and other focal signs.
Hepatic encephalopathy and other metabolic encephalopathies: Severe liver disease can transiently produce bilateral upper motor neuron signs including a positive Babinski sign.

Babinski Reflex vs Normal Plantar Reflex

The plantar reflex and the Babinski response are produced by the same stimulus (stroking the sole of the foot) but differ in the direction of toe movement and in what they indicate clinically.

Normal plantar reflex (negative Babinski): The toes curl downward (plantarflexion) in response to the plantar stimulus. This is the expected response in neurologically intact individuals over approximately two years of age.
Positive Babinski sign (extensor plantar response): The big toe extends upward (dorsiflexion) and the other toes fan outward (abduction) in response to the plantar stimulus. This indicates failure of the corticospinal tract's inhibitory control of the reflex arc, caused by upper motor neuron dysfunction.

When a Babinski Sign Needs Medical Attention

The Babinski sign itself is not a diagnosis; it is a neurological finding that guides further assessment. Medical attention is needed in the following situations.

New or sudden onset of a positive Babinski sign in an adult, particularly along with weakness, numbness, speech difficulty or facial deviation.
A persistent positive Babinski sign on neurological examination that has not been previously evaluated.
Babinski sign persisting beyond 24 months of age in a child.
A positive Babinski sign in a patient with known spinal cord disease that is new or worsening along with other new signs.

Conclusion

The Babinski reflex is one of the most informative single tests in the neurological examination. In infants under two years, a positive response is expected and reflects normal neurological immaturity. In adults and in children over two years a positive Babinski sign is a clinically significant indicator of upper motor neuron dysfunction, pointing to a lesion somewhere along the corticospinal tract from the motor cortex to the spinal cord. In India, where stroke and spinal cord disease are prevalent, the Babinski sign is an essential neurological assessment that can guide urgent clinical action.

FAQs

What is the Babinski reflex?

The Babinski reflex is a neurological response produced by stroking the outer edge of the sole. In adults an upward extension of the big toe and fanning of other toes indicates upper motor neuron dysfunction.

How is the Babinski reflex test performed?

The examiner strokes the outer edge of the sole from heel to little toe using a blunt instrument such as a reflex hammer handle or tongue depressor. The direction of toe movement indicates whether the response is normal or abnormal.

Is the Babinski reflex normal in newborns?

Yes a positive Babinski response is normal in infants up to 12 to 18 months of age and sometimes until 24 months. It reflects normal, incomplete myelination of the corticospinal tract in early development.

What does a positive Babinski sign mean?

In children over two years and in adults a positive Babinski sign indicates upper motor neuron (corticospinal) tract dysfunction. Neuroimaging and clinical assessment are required to determine the location and cause of the lesion.

What causes a positive Babinski sign in adults?

The most common causes include stroke, spinal cord injury or compression, multiple sclerosis, brain tumour, ALS, cervical spondylotic myelopathy and hepatic encephalopathy. All involve dysfunction or damage of the upper motor neuron pathway.

How is the Babinski reflex different from a normal plantar reflex?

The normal plantar reflex is a downward curling of the toes in response to stroking the sole. The Babinski sign is the opposite: upward extension of the big toe and fanning of other toes. In adults it always indicates upper motor neuron dysfunction.

At what age does the Babinski reflex disappear?

The positive Babinski response typically disappears between 12 and 18 months as the corticospinal tract myelinates. It may persist until 24 months and still be considered normal. Persistence beyond 24 months warrants paediatric neurology assessment.

Is a positive Babinski sign always a cause for concern?

Not in infants under two years, where it is a normal finding. In older children and adults it is always clinically significant. It can be transiently present in deep sleep, anaesthesia or after a seizure.

What conditions are linked to an abnormal Babinski reflex?

Conditions linked to an abnormal Babinski reflex include stroke, multiple sclerosis, ALS, spinal cord injury or compression, cervical spondylotic myelopathy, brain tumour, cerebral palsy and hepatic encephalopathy. All involve damage to the corticospinal tract.

When should you see a doctor about the Babinski sign?

See a doctor urgently if a positive Babinski sign accompanies new weakness, speech difficulty, facial deviation or numbness, suggesting stroke or spinal cord compression. A positive Babinski sign found incidentally also warrants neurological evaluation.

References

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2. van Gijn J. The Babinski sign: a centenary. Utrecht: Brain. 1996;119(Pt 4):1141–52. https://doi.org/10.1093/brain/119.4.1141

3. Singhal BS. Stroke in India: time trends and challenges in a developing country. Lancet Neurol. 2000;2(Suppl 1):s5. https://doi.org/10.1016/S1474-4422(00)00040-7

4. Kiers L, Desmond P. Neurological signs in dementia. Postgrad Med J. 1999;75(887):515–23. https://doi.org/10.1136/pgmj.75.887.515

5. Fuller G. Neurological examination made easy. 5th ed. Edinburgh: Churchill Livingstone. 2013. https://www.elsevier.com/books/neurological-examination-made-easy/fuller/978-0-7020-5012-5