The Achilles reflex is primarily associated with which nerve root?

The Achilles reflex, also known as the ankle jerk reflex, is primarily associated with the S1 nerve root. This reflex is facilitated by the tibial nerve, which is a branch of the sciatic nerve, and the S1 nerve root is the key player in this reflex arc.

When the Achilles tendon is tapped, sensory receptors in the muscle spindle detect the stretch and send signals to the spinal cord. The reflex pathway involves the S1 nerve root, which sends motor signals back to the gastrocnemius and soleus muscles, causing them to contract and produce the characteristic plantar flexion of the foot. This response serves as a valuable clinical indicator of the integrity of the S1 nerve root and the overall functioning of the nervous system in that region. Understanding this reflex helps in diagnosing conditions related to nerve injuries or dysfunction in the lower limb.