Postural Reflex

Acute exposure to hypoxia increases postural sway, but the underlying neurophysiological factors are unclear. Golgi tendon organs (GTOs), located within the musculotendinous junction (MTJ), provide inhibitory signals to plantar flexor muscles that are important for balance control; however, it is uncertain if GTO function is influenced by hypoxia. The aim of this study was to determine how normobaric hypoxia influences lower limb tendon-evoked inhibitory reflexes during upright stance. We hypothesized that tendon-evoked reflex area and duration would decrease during hypoxia, indicating less inhibition of postural muscles compared to normoxia...

Cerebral palsy (CP) manifests as atypical muscle tone, posture, and movement, and is classified into four main types: extrapyramidal (dyskinetic), spastic quadriplegia, spastic hemiplegia, and spastic diplegia. Patients with CP might move awkwardly because of this since it indicates that their muscles are tense. We report the case of a 13-year-old child who complained of soreness in his right calf muscle and trouble walking over the previous two years. His condition is recognized as spastic diplegic CP. This report aims to understand the impact of neurophysiotherapy procedures in the context of CP...

AIM: Speech pathology is the first-line treatment for inducible laryngeal obstruction (ILO) and involves behavioral techniques to address symptoms and modify maladaptive laryngeal postures. Benefit from speech pathology is reliant on patients engaging in treatment sessions, regular home practice, and generalizing techniques to everyday activities. There is limited research exploring engagement in speech pathology treatment for ILO, particularly from the patient perspective. This study aimed to explore the experiences of living with ILO and how this experience may impact the way patients engage in speech pathology treatment...

The internal capsule (IC) is a vital brain structure housing descending and ascending fiber tracts, with traditional assumptions about the corticobulbar and corticospinal tracts descending through the genu and anterior third of the posterior limb of internal capsule (PLIC), respectively. However, observations of IC infarctions reveal that symptoms often deviate from the expected fiber pattern, prompting a deeper exploration of these complexities. The posterior limb of the IC receives its blood supply from the lenticulostriate branches of the middle cerebral artery and the anterior choroidal artery (AChA)...

KEY CLINICAL MESSAGE: This case report aims to raise a physiotherapy intervention for subjects with SMS. The basis is an active work, based on postural control and balance training. Physiotherapists can play an important role in the management of these subjects. ABSTRACT: Smith-Magenis syndrome (SMS) is a genetic alteration that encompasses a series of psychophysical repercussions that interferes with postural control and the autonomous functionality of the subjects who suffer from it...

The suppression head impulse paradigm (SHIMP) involves suppression of the vestibulo-ocular reflex (VOR) and anticompensatory saccades generated thereof. SHIMP is gaining importance to understand vestibular compensation with its different parameters (VOR gain/peak saccadic velocity PSV/latency of saccades). SHIMP studies are emerging in adults, but pediatric studies have hardly been performed. This study is a retrospective case note audit over a period of 2 months in a tertiary pediatric vestibular center in the United Kingdom to investigate whether SHIMP is safe/robust to be used in children conforming to existing standards/norms in normal children and whether it yields any meaningful inferences in pediatric vestibular hypofunction...

OBJECTIVE: The current study aimed to translate the Hammersmith Infant Neurological Examination (HINE) into Brazilian Portuguese and analyze the reliability of the translated version for a population of Brazilian infants. METHODS: This was a methodological study, approved by the Ethics Committee, carried out between June 2020 and May 2021. HINE is a standardized clinical neurological examination used for the early detection of cerebral palsy. The quantitative section, "neurological examination", contains 26 items scored from 0 to 3 points, divided into five categories: cranial nerve function, posture, movements, muscle tone and reflexes, and reactions...

The reflexive responses to resist external forces and maintain posture result from the coordination between the vestibular system, muscle, tendon, and joint proprioceptors, and vision. Aging deteriorates these crucial functions, increasing the risk of falls. This study aimed to verify whether a training program with water bags, an Instability Neuromuscular training (INT) using the inertial load of water, could positively impact balance ability and dynamic stability. This study was conducted with twenty-two healthy older women aged ≥ 65 (mean age: 74...

Dysphagia is often a long-term problem after ischemic stroke, which are often accompanied by complications and results in poor outcome. This study aimed to investigate the influencing factors associated with the prognosis of dysphagia after senile ischemic stroke and evaluate the diagnostic performance of crucial factors. A total of 192 elderly ischemic stroke patients (96 patients without dysphagia with average age of 69.81 ± 4.61 years and 96 patients with dysphagia with average of 70...

Using a smartphone often involves a sustained head-forward tilt posture, which may deteriorate the mechanism of muscle reaction efficiency or reduce the stiffness of connective tissues of the cervical spine. These changes in muscular and connective tissues can impair cervical spine stability and contribute to developing neck pain symptoms. In this experiment, change in the cervical spine stability associated with a sustained smartphone use posture was evaluated by quantifying the effective stiffness and the reflexive responses of the head to sudden perturbations...

Although there is no doubt from an empirical viewpoint that reflex mechanisms can contribute to tongue motor control in humans, there is limited neurophysiological evidence to support this idea. Previous results failing to observe any tonic stretch reflex in the tongue had reduced the likelihood of a reflex contribution in tongue motor control. The current study presents experimental evidence of a human tongue reflex in response to a sudden stretch while holding a posture for speech. The latency was relatively long (50 ms), which is possibly mediated through cortical-arc...

BACKGROUND: Jaw clenching improves dynamic reactive balance on an oscillating platform during forward acceleration and is associated with decreased mean sway speed of different body regions. OBJECTIVE: It is suggested that jaw clenching as a concurrent muscle activity facilitates human motor excitability, increasing the neural drive to distal muscles. The underlying mechanism behind this phenomenon was studied based on leg and trunk muscle activity (iEMG) and co-contraction ratio (CCR)...

Due to Achilles tendon compliance, passive ankle stiffness is insufficient to stabilise the body when standing. This results in 'paradoxical' muscle movement, whereby calf muscles tend to shorten during forward body sway. Natural variation in stiffness may affect this movement. This may have consequences for postural control, with compliant ankles placing greater reliance upon active neural control rather than stretch reflexes. Previous research also suggests ageing reduces ankle stiffness, possibly contributing to reduced postural stability...

Transcutaneous spinal cord stimulation (TSCS) is gaining popularity as a noninvasive alternative to epidural stimulation. However, there is still much to learn about its effects and utility in assisting recovery of motor control. In this study, we applied TSCS to healthy subjects concurrently performing a functional training task to study its effects during a training intervention. We first carried out neurophysiological tests to characterize the H-reflex, H-reflex recovery, and posterior root muscle reflex thresholds, and then conducted balance tests, first without TSCS and then with TSCS...

Chronic imbalance is a major complaint of patients suffering from bilateral vestibulopathy (BV) and is often reported by patients with chronic unilateral vestibulopathy (UV), leading to increased risk of falling. We used the Central SensoriMotor Integration (CSMI) test, which evaluates sensory integration, time delay, and motor activation contributions to standing balance control, to determine whether CSMI measures could distinguish between healthy control (HC), UV, and BV subjects and to characterize vestibular, proprioceptive, and visual contributions expressed as sensory weights...

Balance involves several sensory modalities including vision, proprioception and the vestibular system. This study aims to investigate vestibulospinal activation elicited by tone burst stimulation in various muscles and how head position influences these responses. We recorded electromyogram (EMG) responses in different muscles (sternocleidomastoid-SCM, cervical erector spinae-ES-C, lumbar erector spinae-ES-L, gastrocnemius-G, and tibialis anterior-TA) of healthy participants using tone burst stimulation applied to the vestibular system...

BACKGROUND: Although head elevation is an early first-line treatment for elevated intracranial pressure (ICP), the use of the head-down or prone position in managing neurocritical patients is controversial because a change in a position directly affects the intracranial and cerebral perfusion pressure, which may cause secondary brain injury and affect patient outcomes. This study compared the effects of two postural drainage positions (30° head-up tilt and 0° head flat) on the prognosis of neurocritical care patients with complicated pneumonia and a clinical pulmonary infection score (CPIS) ≥5 points to provide a reference for selecting appropriate postural drainage positions for patients with pneumonia in neurocritical care units...

BACKGROUND: Acute lateral ankle sprains (ALAS) are associated with long-term impairments and instability tied to altered neural excitability. Arthrogenic muscle inhibition (AMI) has been observed in this population; however, relationships with injury-related impairments are unclear, potentially due to the resting, prone position in which AMI is typically measured. Assessing AMI during bipedal stance may provide a better understanding of this relationship. METHODS: AMI was assessed in 38 young adults (19 ALAS within 72 h of injury: 10 males, 21...

Individuals with Parkinson's disease (PD) and freezing of gait (FOG) have a loss of presynaptic inhibition (PSI) during anticipatory postural adjustments (APAs) for step initiation. The mesencephalic locomotor region (MLR) has connections to the reticulospinal tract that mediates inhibitory interneurons responsible for modulating PSI and APAs. Here, we hypothesized that MLR activity during step initiation would explain the loss of PSI during APAs for step initiation in FOG (freezers). Freezers (n = 34) were assessed in the ON-medication state...

BACKGROUND: The goal of post-stroke early rehabilitation is to regain ambulation, standing and balance. OBJECTIVE: The purpose of this study was to investigate the effects of vestibular and somatosensory rehabilitation in addition to early rehabilitation on balance in patients with early subacute stroke. DESIGN AND SETTING: A randomized controlled trial was conducted at a university hospital. METHODS: The study was included 52 hemiplegic hospitalized early suacute stroke patients...