H reflex

(redirected from H-reflex)
Also found in: Wikipedia.

H re·flex

a monosynaptic reflex consistently obtained in normal adults only by electrically stimulating the tibial nerve, generally in the popliteal fossa, while recording from the gastrocnemius-soleus muscle group; similar to the clinically elicited Achilles reflex, except that the neuromuscular spindles are bypassed. Widely used in the EMG laboratory to diagnose S1 radiculopathies and polyneuropathies.

H reflex

[after Johann Hoffmann, who described it in 1918] See: reflex

H reflex

In electrodiagnostic studies of spinal reflexes, the time required for a stimulus applied to a sensory nerve to travel to the spinal cord and return down the motor nerve.
See: F response
See also: reflex
References in periodicals archive ?
The functional significance of changes in the H-reflex response to functional ambulation in humans has not been demonstrated [43,103-105].
Douglas Watt of McGill University, H-Reflex found that reflex activation of the calf muscles (spinal cord excitability) decreased by about 35% in weightlessness, which could result in exercise in space being less effective, posing a problem that will need to be studied further for future long-duration missions.
Latency of the soleus H-reflex was normal, and reciprocal suppression by dorsal flexion of the foot remained.
It is well documented that any changes in H-reflex amplitude, latency and recovery time reflect the changes in spinal motor neuron excitability [8,11,12].
2010) also show significant increase in peak torque but not H-reflex and suggest the changes might be related to myosin light chain phosphorylation as the possible mechanism that facilitates the increase in force production.
EMG may detect myopathic and neuropathic changes including a delay in the H-reflex with the affected leg in a flexed, adducted, and internally rotated (FAIR) position as compared with the same H-reflex in the normal anatomic position.
Effects of therapeutic passive exercise of hip and knee joints on the soleus H-reflex.
Action potentials in alpha motor neurons activate the muscle and excitation of the muscle can be detected in the form of an H-reflex wave on the EMG tracing.
The H-reflex was first described by Paul Hoffmann in 1910, (10) and has been used extensively as a technique for studying sensorimotor integration and spinal cord adaptations accompanying acquisition and maintenance of motor skills.