Potentiation of `late' responses evoked in muscles during effort

Evidence for changes in segmental motoneurone pools by chronic cerebellar stimulation and its clinical significance.

“…a more widcspread presence of H reflexes occurs in abnormal states (Magladery et al, 1952;French et al, 1961;Thorne, 1965) and has been considered an "indication of chronic upper motoneurone dysfunction" (Garcia-Mullin and Mayer, 1972). On the other hand, responses with the characteristics of H reflexes may appear in a wider distribution in normal states with muscle contraction (Hagbarth, 1962), and this may also alter the responses obtained with supramaximal stimulation (Upton et al, 1971). Little if any baseline muscle activity was present in the data analysed so that it is unlikely that contraction of the muscle from which the responses were recorded was a major determinant in the results.…”

Strength training-induced responses in older adults: attenuation of descending neural drive with age

“…Indeed, this is an important aspect since it also reflects the changes of the fast twitch muscle fibers, which are closely linked to balance adjustments and fall prevention (Hvid et al 2010). The V-wave methodology, an electrophysiological variant of the H-reflex technique, evoked in the triceps surae muscles during maximal muscle contraction has been applied for this frame of testing in several studies (Upton et al 1971;Aagaard et al 2002;Duclay and Martin 2005;Fimland et al 2009;Ekblom 2010;Fimland et al 2010;Fimland et al 2011;Vila-Cha et al 2012). The V-wave is typically normalized to the maximal M-wave (V/M ratio), and its magnitude is suggested to reflect neural drive to the muscle, as well as spinal excitability and pre/ postsynaptic inhibition (Upton et al 1971;Aagaard et al 2002;Aagaard 2003).…”

“…The V-wave methodology, an electrophysiological variant of the H-reflex technique, evoked in the triceps surae muscles during maximal muscle contraction has been applied for this frame of testing in several studies (Upton et al 1971;Aagaard et al 2002;Duclay and Martin 2005;Fimland et al 2009;Ekblom 2010;Fimland et al 2010;Fimland et al 2011;Vila-Cha et al 2012). The V-wave is typically normalized to the maximal M-wave (V/M ratio), and its magnitude is suggested to reflect neural drive to the muscle, as well as spinal excitability and pre/ postsynaptic inhibition (Upton et al 1971;Aagaard et al 2002;Aagaard 2003). Although it may be difficult to identify the exact site of the motor system responsible for a difference in V-wave amplitude, it may be used in combination with the H-reflex technique to more specifically determine the sites and mechanisms of neural changes (Aagaard et al 2002;Vila-Cha et al 2012), since the H-reflex is more dependent on motoneuron excitability (Misiaszek 2003;Ekblom 2010;Vila-Cha et al 2012), whereas the V-wave is more sensitive to supraspinal activation of the motoneuron pool.…”

Clinical Application of Silent Period for the Evaluation of Neuro-Muscular Function in the Field of the Sports Medicine and Rehabilitation

“…Therefore, it has been thought that a variation of the silent period may be able to become an index of the degree of facilitation of the brainstem or motor cortex. So, the origin of silent period that we used in this study is thought to be influenced by muscle spindle function, afferent inhibited impulse from Golgi tendon organ or Ia fiber, recurrent inhibition in the spinal cord, inhibitive mechanism of cerebral cortex (Higgins & Lieberman, 1968, Upton et al, 1971, Anastasijevic & Vuco, 1980. And we have tried to apply the silent period to clarify the magnitude of facilitation of the brainstem or motor cortex in the field of physical therapy.…”

“…the excitability of the spinal cord, brainstem or motor cortex (Roby-Brami & Bussel, 1987, Upton et al, 1971, Kuroiwa, 1986. Therefore, it has been thought that a variation of the silent period may be able to become an index of the degree of facilitation of the brainstem or motor cortex.…”