<prompt> H-reflex is useful in diagnosing:L3 radiculopathyL4 radiculopathyL5 radiculopathyS1 radiculopathy  <response>: Ans. d. S1 radiculopathy Ref Harrison 19e p442e-5, 18e p45-46 ebookH-reflex is useful in diagnosing S1 radiculopathy.The H-reflex is easily recorded only from the soleus muscle S1 in normal adults. It is elicited by low-intensity stimulation of the tibial nerve and represents a monosynaptic reflex in which spindle la afferent fibers constitute the afferent arc and alpha motor axons the efferent pathway. The H-reflexes are often absent bilaterally in elderly patients or with polyneuropathies and may be lost unilaterally in S1 radiculopathies. - Harrison 18e p45-46 ebookH-Reflex StudiesThe H reflex is easily recorded only from the soleus muscle S1 in normal adults.It is elicited by low-intensity stimulation of the tibial nerve and represents a monosynaptic reflex in which spindle la afferent fibers constitute the afferent arc and alpha motor axons the efferent pathway.The H reflexes are often absent bilaterally in elderly patients or with polyneuropathies and may be lost unilaterally in S1 radiculopathiesQ. 