Progressive Adaptation of the Soleus H-Reflex With Daily Training at Walking Backward

2003 ◽  
Vol 89 (2) ◽  
pp. 648-656 ◽  
Author(s):  
Cyril Schneider ◽  
Charles Capaday
Keyword(s):  
Motor Program ◽  
High Amplitude ◽  
H Reflex ◽  
Adaptive Plasticity ◽  
Reflex Activity ◽  
Reflex Modulation ◽  
Surprising Result ◽  
Backward Walking ◽  
Rehabilitation Programs ◽  
Daily Training

When untrained subjects walk backward on a treadmill the amplitude of the soleus H-reflex in midswing is equal to or exceeds the value in stance. This is a surprising result because during the swing phase of backward walking the soleus is inactive and its antagonist, the tibialis anterior, is active. We suggested that the high amplitude of the soleus H-reflex in late swing reflects task uncertainties, such as estimating the moment of foot contact with the ground and losing balance. In support of this idea we show that when untrained subjects held on to handrails the unexpected high-amplitude H-reflex during midswing was no longer present. We therefore asked whether daily training at this task without grasping the handrails would adaptively modify the H-reflex modulation pattern. In this event, within 10 days of training for 15 min daily, the anticipatory reflex activity at the beginning of training was gradually abated as the subjects reported gaining confidence at the task. However, when adapted subjects were made to walk backward with their eyes shut, the anticipatory reflex activity in midswing returned immediately. The reflex changes as a result of training were not due to changes in the motor activity or kinematics; they are likely part of the motor program controlling backward walking. This adaptive phenomenon may prove to be a useful model for studying the neural mechanisms of motor learning and adaptive plasticity in humans and may be relevant to rehabilitation programs for neurological patients.

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.

Are Epileptic Spasms a Seizure Type for the Insular Region?

2020 ◽  
Vol 51 (04) ◽  
pp. 295-297 ◽  
Author(s):  
Volodymyr Kharytonov ◽  
Olivier Dulac
Keyword(s):  
Slow Wave ◽  
Late Onset ◽  
Motor Program ◽  
High Amplitude ◽  
The Other ◽  
Seizure Type ◽  
Wave Characteristic ◽  
The Third ◽  
Epileptic Spasms ◽  
Insular Region

AbstractTwo patients with insular and striatal postnatal scar had epileptic spasms (ES) that were asymmetrical and the only seizure type, whereas none of the usual ictal symptoms of insular seizures occurred. Ictal electroencephalography (EEG) showed the high-amplitude slow-wave characteristic of ES. Vigabatrin remained efficient for over 4 years for one patient and right into the third decade for the other one. Such ES are distinct from infantile and late onset spasms. Furthermore, these observations suggest that in ES insular epilepsy triggers paroxysmal activation of the striatum, and that vigabatrin inhibits the striatal startle motor program, thus interrupting the corticostriatal loop.

scholarly journals H-Reflex Modulation During Walking in Spastic Paretic Subjects

1991 ◽  
Vol 18 (4) ◽  
pp. 443-452 ◽  
Author(s):  
J.F. Yang ◽  
J. Fung ◽  
M. Edamura ◽  
R. Blunt ◽  
R.B. Stein ◽  
...  
Keyword(s):  
Tibialis Anterior ◽  
Stance Phase ◽  
Normal Subjects ◽  
Swing Phase ◽  
H Reflex ◽  
Reflex Modulation ◽  
Healthy Individuals ◽  
Step Cycle ◽  
Common Pattern ◽  
Slight Depression

ABSTRACT:Hoffmann (H) reflexes were elicited from the soleus muscle during treadmill walking in 21 spastic paretic patients. The soleus and tibialis anterior muscles were reciprocally activated during walking in most patients, much like that observed in healthy individuals. The pattern of H-reflex modulation varied considerably between patients, from being relatively normal in some patients to a complete absence of modulation in others. The most common pattern observed was a lack of H-reflex modulation through the stance phase and slight depression of the reflex in the swing phase, considerably less modulation than that of normal subjects under comparable walking conditions. The high reflex amplitudes during periods of the step cycle such as early stance seems to be related to the stretch-induced large electromyogram bursts in the soleus in some subjects. The abnormally active reflexes appear to contribute to the clonus encountered during walking in these patients. In three patients who were able to walk for extended periods, the effect of stimulus intensity was examined. Two of these patients showed a greater degree of reflex modulation at lower stimulus intensities, suggesting that the lack of modulation observed at higher stimulus intensities is a result of saturation of the reflex loop. In six other patients, however, no reflex modulation could be demonstrated even at very low stimulus intensities.

Quadriceps H-Reflex Modulation During Pedaling

2006 ◽  
Vol 96 (1) ◽  
pp. 197-208 ◽  
Author(s):  
Birgit Larsen ◽  
Michael Voigt
Keyword(s):  
Neural Control ◽  
Vastus Lateralis ◽  
Phase Speed ◽  
Rectus Femoris ◽  
Quadriceps Muscle ◽  
H Reflex ◽  
Movement Speed ◽  
Reflex Modulation ◽  
Motor Recruitment ◽  
And Task

The main aims of this study were 1) to investigate possible phase-, speed-, and task-dependent changes in the quadriceps H-reflex during pedaling, and to achieve this, 2) to develop an optimized H-reflex recording and processing procedure for recording of quadriceps H-reflexes during movement. It was hypothesized that the behavior of the quadriceps H-reflex concerning phase, speed, and task dependency corresponds to the behavior of the soleus H-reflex during rhythmical leg movements. The applied H-reflex procedure appeared to be reliable for obtaining the quadriceps H-reflex modulation during leg movement. The vastus lateralis (VL) and rectus femoris (RF) H-reflexes showed a phase-dependent modulation during pedaling at a frequency of 80 rpm with almost parallel changes in the reflex amplitude and motor recruitment level. However, when the speed of movement was reduced from 80 to 40 revolutions per minute (rpm) and crank load simultaneously increased (i.e., a halving of the movement speed with a constant motor recruitment level), the quadriceps H-reflex modulation pattern changed significantly in relation to the pattern of motor recruitment, i.e., at 40 rpm, the reflex excitability remained high during a gradual derecruitment during power generation in downstroke. Comparison of the “operationally defined H-reflex gain function” obtained during 1) pedaling at 80 rpm and 2) isometric quadriceps contractions in sitting position showed no significant task-dependent changes in the quadriceps H-reflex. Consequently, the hypothesis was only partly corroborated, and the findings indicate differences in the neural control of the soleus and the quadriceps muscle during rhythmical movements.

Phase-Dependent Inhibition of H-Reflexes During Walking in Humans Is Independent of Reduction in Knee Angular Velocity

1999 ◽  
Vol 82 (2) ◽  
pp. 747-753 ◽  
Author(s):  
M. Garrett ◽  
T. Kerr ◽  
B. Caulfield
Keyword(s):  
Angular Velocity ◽  
Knee Joint ◽  
Soleus Muscle ◽  
Normal Subjects ◽  
Afferent Input ◽  
H Reflex ◽  
Short Latency ◽  
Reflex Modulation ◽  
Reflex Responses ◽  
Knee Movement

The purpose of this investigation was to investigate whether reduction in impulses arising from stretch of the quadriceps by restricting rapid knee flexion in early swing would affect inhibition of the H-reflex during swing. The contribution of afferent input arising from knee angular velocity to phase-dependent modulation of short-latency responses in the soleus was studied by simultaneously measuring joint velocity and soleus H-reflex responses at midstance and midswing phases of treadmill walking in 15 normal subjects. Stimulus strength was varied so that both maximal M and H waves were identified in each subject at midswing and midstance with the knee unrestricted (UK) and with knee movement restricted (RK), using a full leg bivalved cast to immobilize the knee joint. All subjects exhibited short-latency reflex responses in the soleus muscle. The H/M ratio at midswing was significantly reduced compared with midstance under both UK and RK walking conditions ( P < 0.0001). When compared with UK walking, knee joint angular velocity during RK walking was significantly reduced at midswing ( P < 0.001) and midstance ( P < 0.005) compared with UK. There were, however, no significant differences in H/M ratios at midswing and midstance between UK and RK walking tests. Inhibition of the H-reflex in the soleus muscle during swing was not affected by significant reduction in knee angular velocity. These results indicate that the sensory input from changes in angular velocity at the knee does not lay the inhibitory foundation of phase-related reflex modulation in the ankle extensors during walking as suggested by Brooke and colleagues.

scholarly journals Associations between prefrontal cortex activation and H-reflex modulation during dual task gait

2014 ◽  
Vol 8 ◽  
Author(s):  
Daan Meester ◽  
Emad Al-Yahya ◽  
Helen Dawes ◽  
Penny Martin-Fagg ◽  
Carmen Piñon
Keyword(s):  
Prefrontal Cortex ◽  
Dual Task ◽  
H Reflex ◽  
Reflex Modulation

scholarly journals Changes in soleus H-reflex modulation after treadmill training in children with cerebral palsy

Brain ◽  
2008 ◽  
Vol 132 (1) ◽  
pp. 37-44 ◽  
Author(s):  
Maike Hodapp ◽  
Julia Vry ◽  
Volker Mall ◽  
Michael Faist
Keyword(s):  
Cerebral Palsy ◽  
H Reflex ◽  
Treadmill Training ◽  
Reflex Modulation ◽  
Children With Cerebral Palsy

610 On neural mechanisms of soleus H-reflex modulation during walking in healthy subjects

2008 ◽  
Vol 2007.20 (0) ◽  
pp. 223-224
Author(s):  
Masako FUJITA ◽  
Kiyotaka KAMIBAYASHI ◽  
Tsuyoshi NAKAJIMA ◽  
Makoto TAKAHASHI ◽  
Shin-ichiro YAMAMOTO ◽  
...  
Keyword(s):  
Healthy Subjects ◽  
H Reflex ◽  
Neural Mechanisms ◽  
Reflex Modulation

Cyclic H-Reflex Modulation in Resting Forearm Related to Contractions of Foot Movers, Not to Foot Movement

2003 ◽  
Vol 90 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Gabriella Cerri ◽  
Paola Borroni ◽  
Fausto Baldissera
Keyword(s):  
Plantar Flexion ◽  
Motor Command ◽  
H Reflex ◽  
Reflex Modulation ◽  
Phase Coupling ◽  
Foot Kinematics ◽  
Reflex Excitability ◽  
Movement Frequency ◽  
Before And After ◽  
Foot Loading

During rhythmic voluntary oscillations of the foot, the excitability of the H-reflex in the Flexor Carpi Radialis (FCR) muscle of the resting prone forearm increases during the foot plantar-flexion and decreases during dorsiflexion. It is known that, when the two extremities are moved together, isodirectional (in-phase) coupling is the preferred form of movement association. Thus the above pattern of the H-reflex excitability modulation may favor the preferred coupling between the two limbs. To gain some clues about its origin, FCR H-reflex excitability was tested before and after modifying the phase relations between the activation [electromyogram (EMG)] of foot movers and foot movement, either by loading of the foot or by changing the movement frequency. After foot loading, the movement cycle was consistently delayed with respect to the onset of the EMG in Soleus (Sol) or Tibialis Anterior (TA) muscles. Simultaneously, the FCR H-reflex modulation advanced by that same amount with respect to the foot movement, thus remaining phase-locked to the EMG onsets. Similarly, when movement frequency was varied step-wise between 1.0 and 2.0 Hz, the foot movement was progressively delayed with respect to both the EMG onset (Sol and TA) and the FCR H-reflex modulation, so that the phase relation between the motor command to the foot and the H-modulation in the forearm remained constant. These results suggest that modulation of H-reflex in the forearm is tied to leg muscle contraction, rather than to foot kinematics, and point to a central, rather than kinesthetic, origin for the modulation.

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