What is meant by reflex test?
Christopher Pierce
Updated on April 20, 2026
Reflex tests are performed as part of a neurological exam, either a “mini-exam” done to quickly confirm integrity of the spinal cord, or a more complete exam performed to diagnose the presence and location of spinal cord injury or neuromuscular disease. Deep tendon reflexes are responses to muscle stretch.
What is a normal Achilles reflex?
The Achilles reflex is a monosynaptic stretch reflex similar to the patellar reflex. In the Achilles reflex, the hammer taps the Achilles tendon while the foot is dorsiflexed, and the foot, in response, should jerk toward the plantar surface. The Achilles reflex originates in the S1 and S2 nerve roots.
What is a normal reaction for the plantar reflex?
A normal reaction consists of flexion of the great toe or no response. An abnormal response in adults consists of dorsiflexion of the great toe with an associated fanning of the other toes. This response is the Babinski sign and indicates dysfunction of the corticospinal tract but no further localization.
How to measure conduction velocity in a human reflex arc?
To measure conduction velocity in a human reflex arc, using the Achilles tendon as the initiator of a reflex and contraction of the gastrocnemius muscle as the response (extracellular recording).
What is the electrical equivalent of the stretch reflex?
The H reflex is the electrical equivalent of the monosynaptic stretch reflex and is normally obtained in only a few muscles. It is elicited by selectively stimulating the Ia fibers of the posterior tibial or median nerve.
How many points are needed to calculate the conduction velocity?
Conduction velocity: two points in time Rate = distance/ time So 2 points are needed I.e.. CV = 20cm/4ms Cannot record a distal conduction Why? Neuromuscular junction Cannot accurately calculate time Conduction Velocity Rate = distance/ time E.g.. Median Nerve:
How do doctors test for stretch reflexes?
To determine this, doctors may also test stretch reflexes in the triceps muscle and the Achilles tendon (ankle-jerk reflex) and compare results. The Achilles reflex is a monosynaptic stretch reflex similar to the patellar reflex.
