keyword
MENU ▼
Read by QxMD icon Read
search

h-reflex

keyword
https://www.readbyqxmd.com/read/29349480/posture-modulates-the-sensitivity-of-the-h-reflex
#1
Serpil Cecen, Imran Khan Niazi, Rasmus Wiberg Nedergaard, Alice Cade, Kathryn Allen, Kelly Holt, Heidi Haavik, Kemal S Türker
The effect of body posture on the human soleus H-reflex via electrical stimulation of the tibial nerve at the popliteal fossa was studied. All parameters that may influence the reflex were controlled stringently. H-reflexes were elicited in three different body postures while keeping the level of background muscle activation to a minimum. The H-reflex curve relative to the M-wave curve did not change significantly in any of the body postures. However, the maximal H-reflex amplitude significantly increased in the prone position compared with the sitting (p = 0...
January 18, 2018: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/29340899/assessing-sensorimotor-excitability-after-spinal-cord-injury-a-reflex-testing-method-based-on-cycling-with-afferent-stimulation
#2
Stefano Piazza, Diego Torricelli, Julio Gómez-Soriano, Diego Serrano-Muñoz, Gerardo Ávila-Martín, Iriana Galán-Arriero, José Luis Pons, Julian Taylor
Several studies have examined spinal reflex modulation during leg cycling in healthy and spinal cord injury (SCI) subjects. However, the effect of cutaneous plantar afferent input on spinal excitability during leg cycling after SCI has not been characterised. The aim of the study was to test the feasibility of using controlled leg cycling in combination with plantar cutaneous electrical stimulation (ES) cycling to assess lower limb spinal sensorimotor excitability in subjects with motor complete or incomplete SCI...
January 17, 2018: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/29329907/influence-of-motor-imagery-on-spinal-reflex-excitability-of-multiple-muscles
#3
Kento Nakagawa, Yohei Masugi, Akira Saito, Hiroki Obata, Kimitaka Nakazawa
The effects of motor imagery on spinal reflexes such as the H-reflex are unclear. One reason for this is that the muscles that can be used to record spinal reflexes are limited to traditional evoking methods Recently, transcutaneous spinal cord stimulation has been used for inducing spinal reflexes from multiple muscles and we aimed to examine the effect of motor imagery on spinal reflexes from multiple muscles. Spinal reflexes evoked by transcutaneous spinal cord stimulation were recorded from six muscles from lower limbs during motor imagery of right wrist extension and ankle plantarflexion with maximum isometric contraction...
January 9, 2018: Neuroscience Letters
https://www.readbyqxmd.com/read/29327170/the-effects-of-a-single-session-of-spinal-manipulation-on-strength-and-cortical-drive-in-athletes
#4
Thomas Lykke Christiansen, Imran Khan Niazi, Kelly Holt, Rasmus Wiberg Nedergaard, Jens Duehr, Kathryn Allen, Paul Marshall, Kemal S Türker, Jan Hartvigsen, Heidi Haavik
PURPOSE: The primary purpose of this study was to investigate whether a single session of spinal manipulation (SM) increases strength and cortical drive in the lower limb (soleus muscle) of elite Taekwondo athletes. METHODS: Soleus-evoked V-waves, H-reflex and maximum voluntary contraction (MVC) of the plantar flexors were recorded from 11 elite Taekwondo athletes using a randomized controlled crossover design. Interventions were either SM or passive movement control...
January 11, 2018: European Journal of Applied Physiology
https://www.readbyqxmd.com/read/29288924/short-term-effects-of-electrical-nerve-stimulation-on-spinal-reciprocal-inhibition-depend-on-gait-phase-during-passive-stepping
#5
Hiroki Obata, Tetsuya Ogawa, Matija Milosevic, Noritaka Kawashima, Kimitaka Nakazawa
A combination of electrical nerve stimulation (ENS) and passive or active cyclic movements (i.e., pedaling and stepping) has been suggested to induce stronger short-term effects in spinal circuits as compared to either intervention alone. The purpose of the present study is to determine whether the effects of ENS during passive stepping are dependent on the timing of the stimulation during the stepping cycle. A total of 10 able-bodied participants were recruited for the study. Two interventions were assessed during passive ground stepping: (1) ENS of the common peroneal nerve (CPN) during the swing phase (ENSswing) and (2) stance phase (ENSstance)...
December 26, 2017: Journal of Electromyography and Kinesiology
https://www.readbyqxmd.com/read/29249176/neural-mechanisms-of-strength-increase-after-one-week-motor-imagery-training
#6
Sidney Grosprêtre, Thomas Jacquet, Florent Lebon, Charalambos Papaxanthis, Alain Martin
The neural mechanisms explaining strength increase following mental training by motor imagery (MI) are not clearly understood. While gains are mostly attributed to cortical reorganization, the sub-cortical adaptations have never been investigated. The present study investigated the effects of MI training on muscle force capacity and the related spinal and supraspinal mechanisms. Eighteen young healthy participants (mean age: 22.5 ± 2.6) took part in the experiment. They were distributed into two groups: a control group (n = 9) and an MI training group (n = 9)...
December 17, 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/29244850/intensity-matters-therapist-dependent-dose-of-spinal-transcutaneous-electrical-nerve-stimulation
#7
Diego Serrano-Muñoz, Julio Gómez-Soriano, Elisabeth Bravo-Esteban, María Vázquez-Fariñas, Julian Taylor, Juan Avendaño-Coy
The intensity used during transcutaneous electrical nerve stimulation (TENS) in both, clinical practice and research studies, is often based on subjective commands such as "strong but comfortable sensation". There is no consensus regarding the effectiveness dose of TENS. The objective was to determine the difference in the effect of spinal TENS on soleus H-reflex modulation when applied by two therapists instructed to apply the stimulation at a "strong but comfortable" intensity. Twenty healthy volunteers divided into two groups: Therapist 1 (n = 10) and Therapist 2 (n = 10)...
2017: PloS One
https://www.readbyqxmd.com/read/29225972/modulation-of-h-reflex-depression-with-paired-pulse-stimulation-in-healthy-active-humans
#8
Preeti D Oza, Shauna Dudley-Javoroski, Richard K Shields
Depression of the Hoffman reflex (H-reflex) is used to examine spinal control mechanisms during exercise, fatigue, and vibration and in response to training. H-reflex depression protocols frequently use trains of stimuli; this is time-consuming and prevents instantaneous assessment of motor neuronal excitability. The purpose of this study was to determine if paired-pulse H-reflex depression is reproducible and whether paired-pulse stimulation adequately estimates the depression induced by the more traditional ten-pulse train...
2017: Rehabilitation Research and Practice
https://www.readbyqxmd.com/read/29199186/neural-adaptations-after-short-term-wingate-based-high-intensity-interval-training
#9
A Vera-Ibañez, D Colomer-Poveda, S Romero-Arenas, M Viñuela-García, G Márquez
OBJECTIVES: This study examined the neural adaptations associated with a low-volume Wingate-based High Intensity Interval Training (HIIT). METHODS: Fourteen recreationally trained males were divided into an experimental (HIIT) and a control group to determine whether a short-term (4 weeks) Wingate-based HIIT program could alter the Hoffmann (H-) reflex, volitional (V-) wave and maximum voluntary contraction (MVC) of the plantar-flexor muscles, and the peak power achieved during a Wingate test...
December 1, 2017: Journal of Musculoskeletal & Neuronal Interactions
https://www.readbyqxmd.com/read/29176947/cortical-contribution-to-linear-non-linear-and-frequency-components-of-motor-variability-control-during-standing
#10
Niklas König Ignasiak, Lars Habermacher, William R Taylor, Navrag B Singh
Motor variability is an inherent feature of all human movements and reflects the quality of functional task performance. Depending on the requirements of the motor task, the human sensory-motor system is thought to be able to flexibly govern the appropriate level of variability. However, it remains unclear which neurophysiological structures are responsible for the control of motor variability. In this study, we tested the contribution of cortical cognitive resources on the control of motor variability (in this case postural sway) using a dual-task paradigm and furthermore observed potential changes in control strategy by evaluating Ia-afferent integration (H-reflex)...
2017: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29144602/neuroplasticity-following-short-term-strength-training-occurs-at-supraspinal-level-and-is-specific-for-the-trained-task
#11
L-S Giboin, B Weiss, F Thomas, M Gruber
AIMS: Different modalities of strength training cause performance enhancements, which are specific for the trained task. However, the involved mechanisms are still largely unknown. It has been demonstrated that strength training could induce neuroplasticity, which might underlie the performance improvements during the first training sessions. Thus, we hypothesized to find task-specific neuroplasticity after a short-term strength training of two distinct strength tasks. METHODS: Young healthy male subjects were exposed to 4 sessions of either maximal isometric explosive (EXPL group, N = 9) or slow sustained (SUS group, N = 10) knee extensions...
November 16, 2017: Acta Physiologica
https://www.readbyqxmd.com/read/29142099/assessing-tms-induced-d-and-i-waves-with-spinal-h-reflexes
#12
Niclas Niemann, Patrick Wiegel, Alexander Kurz, John C Rothwell, Christian Leukel
Transcranial magnetic stimulation (TMS) of motor cortex produces a series of descending volleys known as D- (direct) and I- (indirect) waves. In the present study, we questioned whether spinal H-reflexes can be used to dissect D-waves, early and late I-waves from TMS. We therefore probed H-reflex facilitation at arrival times of D- and I-waves at the spinal level and thereby changed TMS parameters that have previously been shown to have selective effects on evoked D- and different I-waves. We changed TMS intensity and current direction, and applied a double-pulse paradigm known as short-interval intracortical inhibition (SICI)...
November 15, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29140761/limb-segment-load-inhibits-the-recovery-of-soleus-h-reflex-after-segmental-vibration-in-humans
#13
Shih-Chiao Tseng, Richard K Shields
We investigated the effects of vertical vibration and compressive load on soleus H-reflex amplitude and postactivation depression. We hypothesized that, in the presence of a compressive load, limb vibration induces a longer suppression of soleus H-reflex. Eleven healthy adults received vibratory stimulation at a fixed frequency (30 Hz) over two loading conditions (0% and 50% of individual's body weight). H-reflex amplitude was depressed ∼88% in both conditions during vibration. Cyclic application of compression after cessation of the vibration caused a persistent reduction in H-reflex excitability and postactivation depression for > 2...
November 15, 2017: Journal of Motor Behavior
https://www.readbyqxmd.com/read/29126270/neural-plasticity-with-age-unilateral-maximal-strength-training-augments-efferent-neural-drive-to-the-contralateral-limb-in-older-adults
#14
Tiril Tøien, Runar Unhjem, Thomas Storehaug Øren, Ann Charlotte Gjertsen Kvellestad, Jan Hoff, Eivind Wang
Efferent neural drive during strong muscle contractions is attenuated with age, even after lifelong strength training. However, it is unknown if this deterioration may impede contralateral neural plasticity, and limit the clinical value of unilateral strength training. We assessed muscle force-generating capacity, evoked potentials recordings (V-wave and H-reflex normalized to M-wave; V/M-ratio and H/M-ratio) and voluntary activation (VA) in the plantar flexors of the contralateral limb following unilateral maximal strength training (MST) with the dominant limb for three weeks (9 sessions)...
November 4, 2017: Journals of Gerontology. Series A, Biological Sciences and Medical Sciences
https://www.readbyqxmd.com/read/29119209/relationship-between-spasticity-and-spinal-neural-circuits-in-patients-with-chronic-hemiparetic-stroke
#15
Kohei Okuyama, Michiyuki Kawakami, Miho Hiramoto, Kaori Muraoka, Toshiyuki Fujiwara, Meigen Liu
Spasticity is a common problem in patients with stroke that contributes to motor dysfunction. However, the pathophysiological mechanisms underlying spasticity are not fully understood. The purpose of the present study was to explain the relationship between features of spinal neural circuits assessed using electrophysiological techniques and the clinical manifestations of stroke. The participants were 71 patients with chronic hemiparetic stroke. To assess spinal neural circuits, Hmax/Mmax of the forearm flexor muscles and reciprocal inhibition (RI) between forearm extensor and flexor muscles with the H reflex conditioning-test paradigm were measured...
November 8, 2017: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
https://www.readbyqxmd.com/read/29118191/effects-of-muscle-action-type-on-corticospinal-excitability-and-triceps-surae-muscle-tendon-mechanics
#16
Pedro Valadao, Sadao Kurokawa, Taija Finni, Janne Avela
This study investigated if the specific motor control strategy reported for eccentric muscle actions is dependent of muscle mechanical behavior. Motor-evoked potentials (MEP), Hoffman reflex (H-reflex), fascicle length (FL), pennation angle (PA) and fascicle velocity (FV) of soleus (SOL) muscle were compared between isometric and two eccentric conditions. Ten volunteers performed maximal plantarflexion trials in isometric, slow eccentric (25º/s) and fast eccentric (100º/s) conditions, each on a different randomized testing session...
November 8, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/29096208/changes-in-the-soleus-h-reflex-test-and-correlations-between-its-results-and-dynamic-magnetic-resonance-imaging-abnormalities-in-patients-with-hirayama-disease
#17
Chaojun Zheng, Yu Zhu, Feizhou Lu, Dongqing Zhu, Shuo Yang, Xiaosheng Ma, Xinlei Xia, Robert Weber, Jianyuan Jiang
OBJECTIVE: To investigate changes in soleus H-reflex tests in patients with Hirayama disease (HD) and to analyse correlations between these changes and forward-shifting of the cervical cord during neck flexion. METHODS: The amplitude of the soleus H-reflex with and without vibration on the Achilles tendon was recorded bilaterally in 81 HD patients and 34 controls to measure both the vibratory inhibition index (VII) and the Hmax/Mmax ratio. The maximum forward-shifting degree of cervical cord during neck flexion was measured using dynamic magnetic resonance imaging in all HD patients...
October 3, 2017: Clinical Neurophysiology: Official Journal of the International Federation of Clinical Neurophysiology
https://www.readbyqxmd.com/read/29091318/early-electrophysiological-findings-in-acute-inflammatory-demyelinating-polyradiculoneuropathy-variant-of-guillain-barre-syndrome-in-the-pakistani-population%C3%A2-%C3%A2-a-comparison-with-global-data
#18
REVIEW
Ahmad Wali, Dureshahwar Kanwar, Safoora A Khan, Sara Khan
Acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and acute motor axonal neuropathy are the most common variants of Guillian-Barre syndrome documented in the Asian population. However, the variability of early neurophysiologic findings in the Asian population compared to western data has not been documented. Eighty-seven cases of AIDP were retrospectively reviewed for their demographic, clinical, electrophysiological, and laboratory data. Mean age of subjects was 31 ± 8 years with males more commonly affected...
November 1, 2017: Journal of the Peripheral Nervous System: JPNS
https://www.readbyqxmd.com/read/29055385/is-quadriceps-h-reflex-excitability-a-risk-factor-for-patellofemoral-pain
#19
Marcella Ferraz Pazzinatto, Danilo de Oliveira Silva, Evangelos Pappas, Fernando Henrique Magalhães, Fábio Mícolis de Azevedo
Patellofemoral pain (PFP) is one of the most common conditions in orthopedic practice while recent evidence has suggested that it may be a predisposing factor to patellofemoral osteoarthritis. In addition to biomechanical alterations associated with the pathomechanisms underlying PFP, the investigation of neurophysiological alterations has provided novel information in the understanding of the pathophysiology of PFP. For instance, women with PFP present lower amplitude of the vastus medialis (VM) H-reflexes compared to pain-free controls, which suggests that the excitability of spinal reflexes might be a promising tool for discriminating woman with PFP in clinical practice...
October 2017: Medical Hypotheses
https://www.readbyqxmd.com/read/28951323/preparatory-cortical-and-spinal-settings-to-counteract-anticipated-and-non-anticipated-perturbations
#20
Michael Wälchli, Craig D Tokuno, Jan Ruffieux, Martin Keller, Wolfgang Taube
Little is known about how the central nervous system prepares postural responses differently in anticipated compared to non-anticipated perturbations. To investigate this, participants were exposed to translational and rotational perturbations presented in a blocked (anticipated) and a random (non-anticipated) design. The preparatory setting ('central set') was measured by H-reflexes, motor-evoked potentials (MEPs), and short-interval intracortical inhibition (SICI) shortly before perturbation onset in the soleus of 15 healthy adults...
December 4, 2017: Neuroscience
keyword
keyword
73171
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"