The purpose of testing reflexes is to localize neurologic pathology to the central or the peripheral nervous system by looking for evidence of upper motor neuron or lower motor neuron (or peripheral sensory nerve) dysfunction.

Testing of muscle stretch reflexes and testing for the Babinski sign should be performed on all patients as part of a standard neurologic examination.

The muscle stretch reflexes and the Babinski sign are spinal reflexes. In both of these reflexes, the stimulus sends an afferent (sensory) impulse up a sensory nerve into the dorsal root of the spinal cord, which completes the reflex arc by ultimately synapsing on motor neurons within the spinal cord, causing an efferent (motor) response. The corticospinal tract (the upper motor neuron) has an inhibitory influence on the muscle stretch reflexes and the Babinski sign.

See Chapter 37, Examination of the Muscle Stretch Reflexes, and Chapter 38, Testing for the Babinski Response, for testing discussion.

Normally, patients should have intact but not severely hyperactive muscle stretch reflexes. There should also be no Babinski sign in either foot.