Chaddock’s Sign (Chaddock’s Reflex) : Definition, Method, & Positive
Chaddock’s sign is present when the stimulus is applied along the lateral & dorsal aspect of the foot, below the external malleolus.
It is alternative method to elicit plantar reflex when classical method fails.
Plantar Reflex
Definition
- Plantar reflex is a superficial reflex subserved by S1 segment of spinal cord.
Segmental innervation
- Afferent : Tibial nerve
- Root Value : L5, S1, S2
- Efferent : Tibial nerve
Methods
Primary method
Patient is positioned such that the knee is slightly flexed, & thigh externally rotated
↓
Examiner fixes the ankle joint by holding it
↓
Outer aspect of the sole is stroked with a blunt point (key)
Stroke is directed forwards and then curves inwards along the metatarsophalangeal joints, from the little to the big toe
Alternate Methods to Elicit Plantar Reflexes
- Oppenheim’s reflex : A firm stroke with the finger and thumb is applied down either side of the anterior
border of the tibia, greater pressure being applied to the medial side. - Gordon’s sign : Calf muscles are squeezed.
- Chaddock sign
- Schaefer’s sign : Achilles tendon is squeezed.
These reflexes show a positive Babinski response when the reflexogenic area spreads up in the lower limb.
They may be useful in eliciting the Babinski response when the patients are uncooperative or in patients whose soles are extremely sensitive.
Response
Normal response
- Flexion of great toe at the metatarsophalangeal joint, accompanied by adduction of the other toes.
Abnormal response
- Babinski sign (extensor plantar reflex) : Extension of great toe at the metatarsophalangeal joint with or without abduction of the other toes.
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 athetosis or chorea, where the big toe may extend as a response to dystonic posturing.
- If the short flexors of the toes are paralysed (due to lower motor neuron lesion), there may be an inversion of the plantar reflex.
Disclaimer: DoctorAlerts is an educational platform. It does not provide medical advice, diagnosis, or treatment. We neither promote nor sell any type of prescription drug or supplement.
