scholarly journals A Study on H-reflex Change and MVIC Change Depending upon Shouting Type

2009 ◽  
Vol 19 (4) ◽  
pp. 655-661 ◽  
Author(s):  
Ik-Su Jeong ◽  
Cheong-Hwan Oh ◽  
Dong-Jin Lee ◽  
Gun-Hee Lee ◽  
Jin Lee
Keyword(s):  
H Reflex ◽  
Reflex Change

scholarly journals Acquisition of a simple motor skill: task-dependent adaptation and long-term changes in the human soleus stretch reflex

2019 ◽  
Vol 122 (1) ◽  
pp. 435-446 ◽  
Author(s):  
N. Mrachacz-Kersting ◽  
U. G. Kersting ◽  
P. de Brito Silva ◽  
Y. Makihara ◽  
L. Arendt-Nielsen ◽  
...  
Keyword(s):  
Operant Conditioning ◽  
Stretch Reflex ◽  
Conditioning Session ◽  
H Reflex ◽  
Reflex Change ◽  
Reflex Pathways ◽  
Term Change ◽  
Neurologically Normal ◽  
Spinal Stretch Reflex

Changing the H reflex through operant conditioning leads to CNS multisite plasticity and can affect previously learned skills. To further understand the mechanisms of this plasticity, we operantly conditioned the initial component (M1) of the soleus stretch reflex. Unlike the H reflex, the stretch reflex is affected by fusimotor control, comprises several bursts of activity resulting from temporally dispersed afferent inputs, and may activate spinal motoneurons via several different spinal and supraspinal pathways. Neurologically normal participants completed 6 baseline sessions and 24 operant conditioning sessions in which they were encouraged to increase (M1up) or decrease (M1down) M1 size. Five of eight M1up participants significantly increased M1; the final M1 size of those five participants was 143 ± 15% (mean ± SE) of the baseline value. All eight M1down participants significantly decreased M1; their final M1 size was 62 ± 6% of baseline. Similar to the previous H-reflex conditioning studies, conditioned reflex change consisted of within-session task-dependent adaptation and across-session long-term change. Task-dependent adaptation was evident in conditioning session 1 with M1up and by session 4 with M1down. Long-term change was evident by session 10 with M1up and by session 16 with M1down. Task-dependent adaptation was greater with M1up than with the previous H-reflex upconditioning. This may reflect adaptive changes in muscle spindle sensitivity, which affects the stretch reflex but not the H reflex. Because the stretch reflex is related to motor function more directly than the H reflex, M1 conditioning may provide a valuable tool for exploring the functional impact of reflex conditioning and its potential therapeutic applications. NEW & NOTEWORTHY Since the activity of stretch reflex pathways contributes to locomotion, changing it through training may improve locomotor rehabilitation in people with CNS disorders. Here we show for the first time that people can change the size of the soleus spinal stretch reflex through operant conditioning. Conditioned stretch reflex change is the sum of task-dependent adaptation and long-term change, consistent with H-reflex conditioning yet different from it in the composition and amount of the two components.

scholarly journals Soleus H-Reflex Change in Poststroke Spasticity: Modulation due to Body Position

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Wenting Qin ◽  
Anjing Zhang ◽  
Mingzhen Yang ◽  
Chan Chen ◽  
Lijun Zhen ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
Body Position ◽  
Standing Position ◽  
H Reflex ◽  
Hoffmann Reflex ◽  
Unaffected Side ◽  
Reflex Change ◽  
Affected Side ◽  
Motor Neuron Excitability ◽  
Spastic Hemiplegia

Purpose. This study is aimed at exploring how soleus H-reflex change in poststroke patients with spasticity influenced by body position. Materials and Methods. Twenty-four stroke patients with spastic hemiplegia and twelve age-matched healthy controls were investigated. Maximal Hoffmann-reflex (Hmax) and motor potential (Mmax) were elicited at the popliteal fossa in both prone and standing positions, respectively, and the Hmax/Mmax ratio at each body position was determined. Compare changes in reflex behavior in both spastic and contralateral muscles of stroke survivors in prone and standing positions, and match healthy subjects in the same position. Results. In healthy subjects, Hmax and Hmax/Mmax ratios were significantly decreased in the standing position compared to the prone position (Hmax: p = 0.000 , Hmax/Mmax: p = 0.016 ). However, Hmax/Mmax ratios were increased in standing position on both sides in poststroke patients with spasticity (unaffected side: p = 0.006 , affected side: p = 0.095 ). The Hmax and Hmax/Mmax ratios were significantly more increased on the affected side than unaffected side irrespective of the position. Conclusions. The motor neuron excitability of both sides was not suppressed but instead upregulated in the standing position in subjects with spasticity, which may suggest that there was abnormal regulation of the Ia pathway on both sides.

Effect of chlorpromazine on H-reflex recovery curves in normal subjects and schizophrenic patients

1982 ◽  
Vol 78 (4) ◽  
pp. 342-345 ◽  
Author(s):  
John Metz ◽  
Henry H. Holcomb ◽  
Herbert Y. Meltzer
Keyword(s):  
Normal Subjects ◽  
H Reflex ◽  
Recovery Curves ◽  
Schizophrenic Patients

scholarly journals Specific modulation of corticomuscular coherence during submaximal voluntary isometric, shortening and lengthening contractions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dorian Glories ◽  
Mathias Soulhol ◽  
David Amarantini ◽  
Julien Duclay
Keyword(s):  
H Reflex ◽  
Medial Gastrocnemius ◽  
Emg Activity ◽  
Beta Band ◽  
Lengthening Contractions ◽  
Time Frequency ◽  
Corticomuscular Coherence ◽  
Emg Signal ◽  
Voluntary Contractions ◽  
Spinal Excitability

AbstractDuring voluntary contractions, corticomuscular coherence (CMC) is thought to reflect a mutual interaction between cortical and muscle oscillatory activities, respectively measured by electroencephalography (EEG) and electromyography (EMG). However, it remains unclear whether CMC modulation would depend on the contribution of neural mechanisms acting at the spinal level. To this purpose, modulations of CMC were compared during submaximal isometric, shortening and lengthening contractions of the soleus (SOL) and the medial gastrocnemius (MG) with a concurrent analysis of changes in spinal excitability that may be reduced during lengthening contractions. Submaximal contractions intensity was set at 50% of the maximal SOL EMG activity. CMC was computed in the time–frequency domain between the Cz EEG electrode signal and the unrectified SOL or MG EMG signal. Spinal excitability was quantified through normalized Hoffmann (H) reflex amplitude. The results indicate that beta-band CMC and normalized H-reflex were significantly lower in SOL during lengthening compared with isometric contractions, but were similar in MG for all three muscle contraction types. Collectively, these results highlight an effect of contraction type on beta-band CMC, although it may differ between agonist synergist muscles. These novel findings also provide new evidence that beta-band CMC modulation may involve spinal regulatory mechanisms.

scholarly journals Acute Effects of Kinesiology Taping Stretch Tensions on Soleus and Gastrocnemius H-Reflex Modulations

2021 ◽  
Vol 18 (9) ◽  
pp. 4411
Author(s):  
Yung-Sheng Chen ◽  
Shi Zhou ◽  
Zachary J. Crowley-McHattan ◽  
Pedro Bezerra ◽  
Wei-Chin Tseng ◽  
...  
Keyword(s):  
H Reflex ◽  
Triceps Surae ◽  
Reflex Modulation ◽  
Hoffmann Reflex ◽  
Acute Effects ◽  
Physically Active ◽  
M Wave ◽  
Subject Design ◽  
Minor Influence ◽  
Order Paper

This study examined the acute effects of stretch tensions of kinesiology taping (KT) on the soleus (SOL), medial (MG), and lateral (LG) gastrocnemius Hoffmann-reflex (H-reflex) modulation in physically active healthy adults. A cross-over within-subject design was used in this study. Twelve physically active collegiate students voluntarily participated in the study (age = 21.3 ± 1.2 years; height = 175.6 ± 7.1 cm; body weight = 69.9 ± 7.1 kg). A standard Y-shape of KT technique was applied to the calf muscles. The KT was controlled in three tension intensities in a randomised order: paper-off, 50%, and 100% of maximal stretch tension of the tape. The peak-to-peak amplitude of maximal M-wave (Mmax) and H-reflex (Hmax) responses in the SOL, MG, and LG muscles were assessed before taping (pre-taping), taping, and after taping (post-taping) phases in the lying prone position. The results demonstrated significantly larger LG Hmax responses in the pre-taping condition than those in the post-taping condition during paper-off KT (p = 0.002). Moreover, the ΔHmax/Mmax of pre- and post-taping in the SOL muscle was significantly larger during 50%KT tension than that of paper-off (p = 0.046). In conclusion, the stretch tension of KT contributes minor influence on the spinal motoneuron excitability in the triceps surae during rest.

DOES VARYING THE AMPLITUDE OF THE SOLEUS H-REFLEX AFFECT THE GAIN?

1995 ◽  
Vol 27 (Supplement) ◽  
pp. S172
Author(s):  
R. S. Phillips ◽  
R. G. Mynark ◽  
D. M. Koceja
Keyword(s):  
H Reflex

Changes in H-reflex amplitude to muscle stretch and lengthening in humans

2016 ◽  
Vol 27 (5) ◽  
pp. 511-522 ◽  
Author(s):  
Francesco Budini ◽  
Markus Tilp
Keyword(s):  
Human Movement ◽  
Careful Consideration ◽  
H Reflex ◽  
Spinal Reflex ◽  
Neural Pathways ◽  
Static Stretching ◽  
Plantar Flexors ◽  
Reflex Excitability ◽  
Apparent Disagreement ◽  
Shed Light

AbstractSpinal reflex excitability is traditionally assessed to investigate neural adjustments that occur during human movement. Different experimental procedures are known to condition spinal reflex excitability. Among these, lengthening movements and static stretching the human triceps have been investigated over the last 50 years. The purpose of this review is to shed light on several apparent incongruities in terms of magnitude and duration of the reported results. In the present review dissimilarities in neuro-spinal changes are examined in relation to the methodologies applied to condition and measure them. Literature that investigated three different conditioning procedures was reviewed: passive dorsiflexion, active dorsiflexion through antagonists shortening and eccentric plantar-flexors contractions. Measurements were obtained before, during and after lengthening or stretching. Stimulation intensities and time delays between conditioning procedures and stimuli varied considerably. H-reflex decreases immediately as static stretching is applied and in proportion to the stretch degree. During dorsiflexions the inhibition is stronger with greater dorsiflexion angular velocity and at lower nerve stimulation intensities, while it is weaker if any concomitant muscle contraction is performed. Within 2 s after a single passive dorsiflexion movement, H-reflex is strongly inhibited, and this effect disappears within 15 s. Dorsiflexions repeated over 1 h and prolonged static stretching training induce long-lasting inhibition. This review highlights that the apparent disagreement between studies is ascribable to small methodological differences. Lengthening movements and stretching can strongly influence spinal neural pathways. Results interpretation, however, needs careful consideration of the methodology applied.

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