Postcontraction depression of Hoffmann-reflex (H-reflex) amplitudes was examined to study the rationale underlying proprioceptive neuromuscular facilitation relaxation techniques. The time course of H-reflex amplitude depression was used to assess postcontraction changes in motoneuron reflex excitability. Sixteen healthy female subjects performed voluntary isometric plantar-flexion contractions...

It has been shown that the monosynaptic EPSP which was evoked in a motoneurone by a volley in its muscle nerve could be depressed by conditioning volleys in other muscle nerves without any evidence of postsynaptic inhibitory changes in the motoneurone (Frank & Fuortes, 1957; Eccles, Eccles & Magni, 1960, 1961). Eccles et al. (1961) described the time course of this EPSP depression and related t...

A better understanding of autonomic influence on motor reflex pathways in spinal cord injury is important to the clinical management of autonomic dysreflexia and spasticity in spinal cord injured patients. The purpose of this study was to examine the modulation of flexor reflex windup during episodes of induced sympathetic activity in chronic human spinal cord injury (SCI). We simultaneously me...

a deficit in centrally discharged impulses. This implies that an inhibitory reflex either is unmasked or is substituted for the excitatory reflex. Other evidence for the existence of inhibitory reflexes has been found in the manifestation of terminal rebound in reflexes engendered by stimulation of afferent C fibers.'01I The second point of interest is that the spontaneous activity which is inc...

It has been know that, at a small dose, narcotic analgesics depress polysynaptic reflex activity in the spinal cats (1) and nociccptive reflexes in the spinal rats (2), as well as in spinal cats and dogs (3-6), where they do not depress, or slightly enhace the monosynaptic reflex (3). In order to explain this depression induced by narcotic analgesics, it has been suggested that the interneurons...

It has been demonstrated that passive cycling training can modulate the H-reflex spinal pathways in an animal model with complete spinal cord transection and in humans with complete spinal cord injury. The aim of this study was to understand if a similar modulation can be induced in hemiparetic patients. This aspect can be crucial in stroke rehabilitation because a recalibration of activity in ...

Although whole-body vibration (WBV) affects neuromuscular performance, it remains unclear whether the effects are due to spinal reflex potentiation or inhibition, or differ between muscle groups. This study aimed to identify the effect of WBV on measures of spinal reflex excitability (H-reflex) and homosynaptic depression (HD) in the soleus (SOL) and medial gastrocnemius (MG) muscles. H-reflex ...

BACKGROUND Depression of spinal cord motoneuron excitability has been proposed to contribute to surgical immobility. The H-reflex, which measures alpha-motoneuron excitability, is depressed by volatile anesthetics, whereas the action of propofol is unknown. The objective of this study was to determine the effects of propofol anesthesia on the H-reflex. METHODS In 13 patients (group 1), H-refl...