H reflex

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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 ?
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.
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.
Unlike SEMG, MMG is not susceptible to stimulus artifact and appears to provide a complimentary signal source for H-reflex studies.
Motl used clinical measures of spasticity and tests of the H-reflex to determine whether sessions of exercise with a stationary bike could relieve spasticity in MS.
Operant conditioning of H-reflex can correct a locomotor abnormality after spinal cord injury in rats.
Two other clinical findings that point to piriformis syndrome are modification of the H-reflex during examination maneuvers and the so-called "piriformis sign," the asymmetric appearance of the extended limb resulting from external rotation of the effected limb while the patient is in a supine position.
A common method for eliciting a reflex is to grasp the hands and pull them apart--this potentiates the stretch reflex and H-reflex (Delwaide and Toulouse, 1980; Dowman and Wolpaw, 1988).
Only the minimal latency of the tibial F-wave and the latency of the soleus H-reflex exhibited changes after walk loading in patients with LSS (32).
Maintaining the same proportion of activated [alpha]-motor fibers is widely assumed to consistently activate Ia afferents, allowing valid evaluation of H-reflex characteristics, particularly [H.
H-reflex and muscle response (M-wave) measurements (peak-peak amplitude) were recorded in 8 college-aged subjects (3 males and 5 females) following tibial nerve stimulation in the popliteal fossa, using surface electrodes positioned on the soleus muscle.