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Lower Limb Neuro
Lower Limb Neuro

Lower Limb Reflexes

February 15th, 2021


The patellar and ankle reflexes are the major motor reflexes of the lower limb. The strength of the reflex, elicited by tapping on the appropriate tendon, can aid in localising a patient's weakness to the upper motor neuron or lower motor neuron.
  • How to Elicit

  • Patellar - with the patient supine, support the knee from underneath providing slight flexion and strike the patellar tendon below the patella.L3 / L4 myotome
  • Ankle - flex the knee, externally rotate the hip and dorsiflex the foot. Strike the Achilles tendon of the heel.L5 / S1 myotome
If the reflex is difficult to elicit, reassess the reflex while the patient clenches their teeth.
  • Grading of Reflexes

  • 0: no response (hyporeflexive)Lower motor neuron lesion
  • 1+: diminished (low normal)Lower motor neuron lesion
  • 2+: average (normal)
  • 3+: brisk (high normal)Upper motor neuron lesion
  • 4+: very brisk (hyperreflexive)Upper motor neuron lesion


  • Look For

  • Very brisk reflexes.
  • Significance

  • Suggestive of an upper motor neuron lesion.


  • Look For

  • Diminished or absent reflexes.
  • Significance

  • Suggestive of a lower motor neuron lesion.

The Reflex Arc

Golgi tendon organ / muscle spindle   Afferent Neuron
Within the dorsal root ganglion  Interneurons
Within the spinal cord   Efferent Neuron
Within the ventral horn    Muscle
Stimulation of agonist muscle
Inhibition of antagonist muscle
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