Babinski reflex definition
Babinski reflex or the ‘toe phenomenon’, is one of the prime infantile reflexes, named after French neurologist, Joseph Babinski, who was the first to describe the Babinski sign in 1896. This infantile reflex occur because of the contraction of the extensor hallicis longus muscle, leading the baby to flex his big toe in an outward direction in response to a stimulus made on the sole of his foot.
Babinski reflex test in newborns
The health care provider, while checking for this reflex, makes the baby lie on a soft padded bed, holding each of his feet and striking a bud or a Babinski hammer gently on his sole . Normal children will immediately respond by moving their big toe upward with the other toes fanning out . Absence of this reflex on either side is abnormal.
The given video shows a baby responding well to the doctor’s actions by moving his foot in the proper way.
How long does the Babinski sign last in babies
This foot reflex, seen in newborns gradually starts disappearing by the twelfth month or maximum by the time they are two years old, as their central nervous system matures [2, 3].
Babinski reflex abnormalities
Absent Babinski reflex
Babinski reflex gives stability to the infants’ body, preparing their feet to take the first steps. It even ensures a proper coordination between the hips lower limbs and spine .When newborns have no Babinski reflex, it suggests that their central nervous system has not matured properly, or there is some problem in their spinal cord .
You can also try testing your baby at home to check whether this infantile reflex is present or not. If your child does not make adequate toe movements when stroked on the sole of his feet, let your doctor know about it.
Retained Babinski reflex
When children continue to have this infantile reflex even after reaching the age of two, they will have difficulty in placing their foot on the ground with ease. They may also face a problem in balancing themselves as their toes will always be extended outwards, making it problematic for them to walk around comfortably . Retained Babinski reflex may cause the following complications :
- Toe walking
- Flat feet
- Difficulty in paying attention or concentrating
- Weakened ankles
- Being inclined to extend or contract feet while walking
- Might have a claw or hammer toe
Children detected with cerebral palsy or hemiplegia (partial paralysis of the body) will retain their reflexes on the part that has been affected. Babies suffering from autism also have a prolonged Babinski reflex .
Babinski reflex in adults
Adults respond to the normal plantar reflex by moving or contracting their toes downwards. However, Babinski sign present in adults is pathological, occurring because of any neurological disorder, brain tumor, injury to the spinal cord, stroke, meningitis and multiple sclerosis . It is incorrect to categorize Babinski reflex as positive and negative because it will either be present (which is normal for infants and abnormal for adults) or absent (abnormal for babies and normal for adults).[ref]
- http://www.neurology.org/content/53/3/655.full [/ref]