h-reflex

(1) Background : Neuromuscular electrical stimulation (NMES) has beneficial effects on physical functions in Multiple sclerosis (MS) patients. However, the neurophysiological mechanisms underlying these functional improvements are still unclear. This study aims at comparing acute responses in spinal excitability, as measured by soleus Hoffmann reflex (H-reflex), between MS patients and healthy individuals, under three experimental conditions involving the ankle planta flexor muscles: (1) passive NMES (pNMES); (2) NMES superimposed onto isometric voluntary contraction (NMES+); and (3) isometric voluntary contraction (ISO)...

PURPOSE: The aim of the study was to analyze the effects of functional or biomechanical bandages, whether elastic or inelastic, in Chronic Ankle Instability (CAI). METHODS: This review used PubMed, WoS, SCOPUS, and CINAHL following PRISMA and registering in Prospero. Main PICOS: (1) CAI; (2) intervention, functional/biomechanical bandages; (3) comparison, taping effect versus placebo/no taping, or another functional taping; (4) outcomes, improvement of CAI functionality (dynamic/static balance, ankle kinematic, perception, agility and motor control, endurance and strength; (5) experimental and preexperimental studies...

BACKGROUND: Spinal cord injuries (SCI) lead to functional alteration with important consequences such as motor and sensory disorders. The repair strategies developed to date remain ineffective. The adipose tissue-derived stromal vascular fraction (SVF) is composed of a cocktail of cells with trophic, pro-angiogenic and immunomodulatory effects. Numerous therapeutic benefits were shown for tissue reconstitution, peripheral neuropathy and for the improvement of neurodegenerative diseases...

To adequately evaluate the corticospinal and spinal plasticity in health and disease, it is essential to understand whether and to what extent the corticospinal and spinal responses fluctuate systematically across multiple measurements. Thus, in this study, we examined the session-to-session variability of corticospinal excitability for the ankle dorsiflexor tibialis anterior (TA) in people with and without incomplete spinal cord injury (SCI). In neurologically normal participants, the following measures were obtained across 4 days at the same time of day (N = 13) or 4 sessions over a 12-h period (N = 9, at 8:00, 12:00, 16:00, and 20:00): maximum voluntary contraction (MVC), maximum M-wave and H-reflex (Mmax and Hmax ), motor evoked potential (MEP) amplitude, and silent period (SP) after MEP...

INTRODUCTION/PURPOSE: Recently, the use of transcutaneous spinal cord stimulation (TSCS) has been proposed as a viable alternative to the H-reflex. The aim of the current study was to investigate to what extent the two modes of spinal cord excitability investigation would be similarly sensitive to the well-known vibration-induced depression. METHODS: Fourteen healthy participants (8 men and 6 women; age: 26.7 ± 4.8 years) were engaged in the study...

INTRODUCTION/AIMS: In amyotrophic lateral sclerosis (ALS), the role of spinal interneurons in ALS is underrecognized. We aimed to investigate pre- and post-synaptic modulation of spinal motor neuron excitability by studying the H reflex, to understand spinal interneuron function in ALS. METHODS: We evaluated the soleus H reflex, and three different modulation paradigms, to study segmental spinal inhibitory mechanisms. Homonymous recurrent inhibition (H'RI ) was assessed using the paired H reflex technique...

BACKGROUND: Focal extracorporeal shock wave therapy (fESWT) is a physical therapy vastly studied and used for various musculoskeletal disorders. However, the effect of fESWT on central nervous system is still to be determined. OBJECTIVE: To elucidate spinal and supra-spinal mechanisms of fESWT in healthy subjects, in order to widen the spectrum of its clinical applications. METHODS: In this quasi-experimental, unblinded, proof-of-concept clinical study, 10 voluntary healthy subjects underwent fESWT and were assessed immediately before (T0), immediately after (T1) and seven days after (T2) the intervention...

The distribution of activation among muscles from the same anatomical group can be affected by the mechanical constraints of the task, such as limb orientation. For example, the distribution of activation between the gastrocnemius medialis (GM) and lateralis (GL) muscles during submaximal plantarflexion depends on the orientation of the foot in the horizontal plane. The neural mechanisms behind these modulations are not known. The overall aim of this study was to determine whether the excitability of the two gastrocnemius muscles is differentially affected by changes in foot orientation...

Local vibration (LV) applied over the muscle tendon constitutes a powerful stimulus to activate the muscle spindle primary (Ia) afferents which project to the spinal level and are conveyed to the cortical level. This study aimed to identify the neuromuscular changes induced by a 30-minute LV-inducing illusions of hand extension on the vibrated flexor carpi radialis (FCR) and the antagonist extensor carpi radialis (ECR) muscles. We studied the change of the maximal voluntary isometric contraction (MVIC, Experiment 1) for carpal flexion and extension, motor evoked potentials (MEPs, Experiment 2), cervicomedullary motor evoked potentials (CMEPs, Experiment 2), and Hoffmann's reflex (H-reflex, Experiment 3) for both muscles at rest...

PURPOSE: This study aimed to determine the inter-session reliability of quadriceps neuromuscular function measurements in healthy young and older females. METHODS: Twenty-six females aged 19-74 years completed two identical experimental sessions on different days. Quadriceps neuromuscular function measurements included isometric maximal voluntary force, high- and low-frequency twitch force, voluntary and evoked (H-reflex, M-wave) electromyography (EMG), and estimated maximal torque, velocity and power derived from torque-velocity relationships...

OBJECTIVE: Spasticity is a form of muscle hypertonia secondary to various diseases, including traumatic brain injury, spinal cord injury, cerebral palsy, and multiple sclerosis. Medical treatments are available; however, these often result in insufficient clinical response. This review evaluates the role of epidural spinal cord stimulation (SCS) in the treatment of spasticity and associated functional outcomes. METHODS: A systematic review of the literature was performed using the Embase, CENTRAL, and MEDLINE databases...

INTRODUCTION: Post-stroke spasticity (PSS) is a disorder of the sensory-motor control, leading to upper motor neuron lesions manifesting either as intermittent or sustained involuntary activation of muscles. Botulinum neurotoxin-A (BoNT-A) is mostly utilized in a variety of therapeutic indications, and it is effective and safe in the management of focal PSS in the rehabilitation scenario. The study aimed to evaluate the effect of BoNT-A administration on H-reflex of upper and lower limbs following PSS...

The aim of the study was to assess neuromuscular changes during an intermittent fatiguing task designed to replicate fundamental actions and ergonomics of road race motorcycling. Twenty-eight participants repeated a sequence of submaximal brake-pulling and gas throttle actions, interspaced by one maximal brake-pulling, until failure. During the submaximal brake-pulling actions performed at 30% MVC, force fluctuations, surface EMG, maximal M-wave (Mmax ) and H-reflex were measured in the flexor digitorum superficialis...

Spasticity is a hyperexcitability disorder that adversely impacts functional recovery and rehabilitative efforts after spinal cord injury (SCI). The loss of evoked rate-dependent depression (RDD) of the monosynaptic H-reflex is indicative of hyperreflexia, a physiological sign of spasticity. Given the intimate relationship between astrocytes and neurons, i.e., the tripartite synapse, we hypothesized that astrocytes might have a significant role in post-injury hyperreflexia and plasticity of neighboring neuronal synaptic dendritic spines...

Spasticity is a complex and multidimensional disorder that impacts nearly 75% of individuals with spinal cord injury (SCI) and currently lacks adequate treatment options. This sensorimotor condition is burdensome as hyperexcitability of reflex pathways result in exacerbated reflex responses, co-contractions of antagonistic muscles, and involuntary movements. Transcutaneous spinal cord stimulation (tSCS) has become a popular tool in the human SCI research field. The likeliness for this intervention to be successful as a noninvasive anti-spastic therapy after SCI is suggested by a mild and transitory improvement in spastic symptoms following a single stimulation session, but it remains to be determined if repeated tSCS over the course of weeks can produce more profound effects...

PURPOSE: To evaluate the effectiveness of radial extracorporeal shock wave therapy (r ESWT) as an additional treatment modality for spastic equinus deformity in chronic hemiplegic patients. METHODS: 100 eligible stroke patients with calf muscles spasticity were randomized into 2 groups. Group I: 50 patients exposed to rESWT 1.500 pulses, 0.10 mJ to 0.3mJ/mm2, with a frequency 4 Hz once weekly for one month. Group II: 50 patients exposed to Sham rESWT once weekly for one month...

This study aimed to investigate whether acute passive heat stress 1) decreases muscle Maximal Voluntary Contraction (MVC); 2) increases peripheral muscle fatigue; 3) increases spinal cord excitability, and 4) increases key skeletal muscle gene signaling pathways in skeletal muscle. Examining the biological and physiological markers underlying passive heat stress will assist us in understanding the potential therapeutic benefits. MVCs, muscle fatigue, spinal cord excitability, and gene signaling were examined after control or whole body heat stress in an environmental chamber (heat; 82 °C, 10% humidity for 30 min)...

OBJECTIVES: To observe the effect of motion-style scalp acupuncture (MSSA) on H-reflex in rats with post-stroke spasticity (PSS), so as to explore the electrophysiological mechanisms of MSSA against spasticity. METHODS: A total of 36 male SD rats were randomly divided into sham operation, model and MSSA groups, with 12 rats in each group. The stroke model was established by occlusion of the middle cerebral artery. After modeling, rats in the MSSA group were treated by scalp acupuncture (manipulated every 15 min, 200 r/min) at ipsilesional "parietal and temporal anterior oblique line" (MS6) for a total of 30 min, the treadmill training (10 m/min) was applied during the needling retention, once daily for consecutive 7 days...

Spasticity is a chronic neurological complication associated with spinal cord injury (SCI), characterized by increased muscle tone and stiffness. A physiological sign of spasticity is hyperreflexia, evident by the loss of evoked rate-dependent depression (RDD) in the monosynaptic spinal circuit, i.e., H-reflex. Although previous work has shown that SCI-induced astrogliosis contributes to hyperexcitability disorders, including neuropathic pain and spasticity, it is unclear how reactive astrocytes can modulate synaptic transmission within the injured spinal cord...

This study aimed to evaluate the effects of the participant's attention target during repetitive passive movement (RPM) intervention on reciprocal inhibition (RI) and joint movement function. Twenty healthy adults participated in two experiments involving four attention conditions [control (forward attention with no RPM), forward attention (during RPM), monitor attention (monitor counting task during RPM), ankle joint attention (ankle movement counting task during RPM)] during 10-min RPM interventions on the ankle joint...