Manuel E Hernandez

University of Illinois, Urbana-Champaign | UIUC · Department of Kinesiology and Community Health

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Objective: Multiple sclerosis (MS) is a chronic neurological condition of the central nervous system leading to various physical, mental and psychiatric complexities. Mobility limitations are amongst the most frequent and early markers of MS. We evalua...

Background: Age-related changes in the cortical control of standing balance may provide a modifiable mechanism underlying falls in older adults. Thus, this study examined the cortical response to sensory and mechanical perturbations in older adults while standing and examined the relationship between cortical activation and postural control. Meth...

Background: Mobility impairment is common in older persons with multiple sclerosis (MS), and further compounded by general age-related mobility decline but its underlying brain substrates are poorly understood. Objective: Examine fronto-striatal white matter (WM) integrity and lesion load as imaging correlates of mobility outcomes in older perso...

Background and objective: Cognitive and physical functions correlate and delineate aging and disease trajectories. Whereas cognitive reserve (CR) is well-established, physical reserve (PR) is poorly understood. We, therefore, developed and evaluated a novel and more comprehensive construct, individual reserve (IR), comprised of residual-derived CR...

Hypertension (HTN) can lead to non-amnestic cognitive impairment. However, it is unclear if this cognitive impairment affects dual task walking in older adults with HTN. The objective of this study was to evaluate the differences in prefrontal cortex (PFC) oxygenated hemoglobin (HbO2) levels during comfortable walking (CW) and an instrumented trail...

This study examined the effectiveness of a v ision-based framework for m ultiple s clerosis (MS) and Parkinson's disease (PD) gait dysfunction prediction. We collected gait video data from multi-view digital cameras during self-paced walking from MS, PD patients and age, weight, height and gender-matched healthy older adults (HOA). We then...

Changes in emotional state, such as anxiety, have a significant impact on behavior and mental health. However, the detection of anxiety in individuals requires trained specialists to administer specialized assessments, which often take a significant amount of time and resources. Thus, there is a significant need for objective and real-time anxiety...

Objective This systematic review and meta-analysis aimed to review and quantify the changes in gait parameters after therapeutic intervention in adults with neurological disorders. Data Sources A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (01/2000-12/2021). We performed the search algorithm including...

A low-cost quantitative continuous measurement of movements utilizes accelerometers to generate signal outputs to precisely record the positions of extremities during the performance of movements. The procedure can readily be accomplished with inexpensive materials constructed by clinicians throughout the world. The proposed protocol provides the f...

Objective: Treadmill interventions have been shown to promote ‘normal’ walking patterns, as they facilitate the proper movement and timing of the lower limbs. However, prior reviews have not examined which intervention provides the most effective treatment of specific gait impairments in neurological populations. The objective of this systematic re...

Stochastic resonance has been successfully used to improve human movement when using subthreshold vibration. Recent work has shown promise in improving mobility in individuals with unilateral lower limb amputations. Furthering this work, we present an investigation of two different signal structures in the use of stochastic resonance to improve mob...

Hypertension is considered a risk factor for cardiovascular health and non-amnestic cognitive impairment in older adults. While heart rate reserve (HRR) has been shown to be a risk factor for hypertension, how impaired HRR in older adults can lead to cognitive impairment is still unclear. The objective of this study was to examine the effects of HR...

Virtual reality (VR) technology offers an exciting way to emulate real-life walking conditions that may better elicit changes in emotional state. We aimed to determine whether VR technology is a feasible way to elicit changes in state anxiety during walking. Electrocardiogram data were collected for 18 older adult women while they navigated a basel...

Objective(s) The objective is to quantify the changes in gait after treadmill interventions in adults with neurological disorders. Data Sources A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (01/2000-12/2020). We performed the search algorithm including all possible combinations of keywords. Full text...

Objective(s) The objective is to quantify the changes in gait after therapeutic intervention in the adults with neurological disorders. Data Sources A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (01/2000-12/2020). We performed the search algorithm including all possible combinations of keywords. Full...

Chronic progressive neurodegenerative diseases (NDD) cause mobility and cognitive impairments that disrupt quality of life. The learning of new motor skills, motor learning, is a critical component of rehabilitation efforts to counteract these chronic progressive impairments. In people with NDD, there are impairments in motor learning which appear...

Introduction Falls and mobility impairment are the leading cause of injury among older adults and they are induced most frequently during walking [1]. Slipping and tripping during walking are most common causes of falls in older adults, representing failure to react to challenges in environment [2]. It can lead to more severe consequences in older...

Objective: The objective is to quantify the changes in gait after treadmill interventions in adults with neurological disorders. Data Sources: A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (01/2000-12/2020). We performed the search algorithm including all possible combinations of keywords. Full text ar...

Objective: The objective is to quantify the changes in gait after specific intervention in the adults with neurological disorders. Data Sources: A keyword search was performed in four databases: PubMed, CINAHL, Scopus, and Web of Science (01/2000-12/2020). We performed the search algorithm including all possible combinations of keywords. Full text...

INTRO • Little is known about dynamic balance control under dual-task conditions in older adults with osteoarthritis (OA). For example, it is unclear how higher-order cognitive processing changes during challenging motor tasks for OA patients, such as stepping up and down. • Current studies suggest that the center of higher-order cognitive processi...

(1) Functional near-infrared spectroscopy (fNIRS) provides a useful tool for monitoring brain activation changes while walking in adults with neurological disorders. When combined with dual task walking paradigms, fNIRS allows for changes in brain activation to be monitored when individuals concurrently attend to multiple tasks. However, difference...

Osteoarthritis (OA) is known to lead to functional changes in daily activities, little is known about the effect of OA on brain activation while doing sensory organization task (SOT).

Objective: Multiple Sclerosis (MS) is a neurological condition which widely affects people 50-60 years of age. While clinical presentations of MS are highly heterogeneous, mobility limitations are one of the most frequent symptoms. This study examines a machine learning (ML) framework for identifying MS through spatiotemporal and kinetic gait feat...

"A protocol for a low-cost quantitative continuous measurement of movements in the extremities of people with PD (McKay, et al., 2019) was administered to people with PD . . . and age- and sex-matched healthy control participants" (Harrigan, et al., Quantitative continuous measurement of movements in the extremities, 2020). "Healthy control parti...

Background and Purpose Tai Ji Quan (TJQ) practice has been recommended for reducing falls in older adults, but a gap exists in our understanding of the neuromuscular mechanisms underlying TJQ practice benefits. This study aims to quantify and validate neuromuscular mechanisms underlying TJQ practice benefits in older adults. Materials and methods...

Downward reaching may lead to falls in older adults, but the underlying mechanisms are poorly understood, particularly in older women with osteoarthritis. Given the importance of attentional resources when maintaining balance in balance-demanding conditions, functional near-infrared spectroscopy may provide a lens to the attentional resource alloca...

Background Older adults experience greater cognitive motor interference (CMI) due to declines in cognitive and physical function. Although aerobic fitness has beneficial effects on cognition, its association with CMI is not clear. Aims This study aims to investigate the effects of aerobic fitness on CMI during self-paced treadmill walking in older...

This study provide an important relationship between different levels of anxiety and prefrontal cortical activation among older women with and without Osteoarthritis. These anxiety induced virtual reality environments can serve as a rehabilitation tool for older adults at risk of anxiety disorder and fall. These links are important to explore as hi...

Walking is no longer considered an automated activity in diseased population. Due to which, examining its impact on brain will help in designing better rehabilitation paradigms. As Dual task walking such as cooking is linked with fall risk and cognitive impairment in older adults, it is important to examine its impact on health of different populat...

Objective The objective of this systematic review and meta-analysis (PROSPERO registration No CRD42020192121) is to review existing literature focusing on effects of different dual task paradigms on walking speed in older adults with and without Mild Cognitive Impairment. Methods (1) Data Sources: PubMEd, Cumulative Index of Nursing and Allied Hea...

Osteoarthritis (OA) is a musculoskeletal disease that affects balance control in older adults. The ability to restore balance following sudden, unexpected perturbations is critical to avoid falls, particularly for persons with OA. However, a significant gap exists in our understanding of reflexive postural control changes due to OA, and the mechani...

Individuals with multiple sclerosis (MS) experience gait impairments, particularly while dual-tasking, that contribute to an increased risk of falls. Because falls negatively impact participation and quality of life, it is essential to examine how to improve dual-tasking gait. However, no studies, to date, have examined how gait variability is affe...

Electroencephalography (EEG) is a commonly used method for monitoring brain activity. Automating an EEG signal processing pipeline is imperative to the exploration of real-time brain computer interface (BCI) applications. EEG analysis demands substantial training and time for removalof distinct unwanted independent components (ICs), gener-ated via...

The incidence of fall-related injuries in older adults is high. Given the significant and adverse outcomes that arise from injurious falls in older adults, it is of the utmost importance to identify older adults at greater risk for falls as early as possible. Given that balance dysfunction provides a significant risk factor for falls, an automated...

"We hypothesized that (1) correlation of (A) the output of instrumentation to generate quantitative continuous measurements of movements and (B) the quantitative measurements of trained examiners using structured ratings of movements would generate the tools to differentiate the movements of (A) Parkinson's disease (PD), (B) parkinsonian syndromes,...

Unsupervised home exercise is a major component of physical therapy (PT). This study proposes an inexpensive, inertial measurement unit-based wearable device to capture kinematic data to facilitate exercise. However, conveying and interpreting kinematic data to non-experts poses a challenge due to the complexity and background knowledge required th...

The amount of home-based exercise prescribed by a physical therapist is difficult to monitor. However, the integration of wearable inertial measurement unit (IMU) devices can aid in monitoring home exercise by analyzing exercise biomechanics. The objective of this study is to evaluate machine learning models for classifying nine different upper ext...

A low-cost quantitative structured office measurement of movements in the extremities of people with Parkinson's disease [1,2] was performed on people with Parkinson's disease, multiple system atrophy, and age-matched healthy volunteers. Participants underwent twelve videotaped procedures rated by a trained examiner while connected to four accelero...

This investigation examined age-related differences in neck muscle activation latency in response to anterior and posterior postural perturbations to understand the potential implications in fall-related traumatic brain injuries. 57 adults were recruited and categorized into 3 groups based on age: Young (18-30 years old), Young-Old (60-74 years) an...

Mobility impairments are prevalent in older adults. Whereas walking had traditionally been viewed as an autonomous process, evidence over the last decade has shown that cognitive processes such as attention and executive function have a significant impact on gait function in older adults. However, the exact neural mechanisms underlying difficulties...

We study the interaction between balance function and anxiety in humans via a virtual reality based experimental setup, fundamentally designed to examine postural control and neurological feedback during balance-demanding height and perturbation shifts, while in quiet stance. In this work, sensory organization balance test (SOT) was utilized to qua...

Heart rate reserve (HRR) has been shown to be associated with cardiovascular function in older adults, but much is still unknown how the heart rate reserve level affects cognitive control while dual-task walking. In this study, we aim to determine the relationship between heart rate reserve level and change in prefrontal cortical (PFC) activation p...

Objectives: To systematically review and quantitatively synthesize the existing evidence of motor learning in persons with Multiple Sclerosis (PwMS). Data sources: PubMed, CINAHL, and Web of Science were searched using the terms: multiple sclerosis, task learning, motor learning, skill learning, performance learning. Study selection: Studies h...

We examine the feasibility and effectiveness of a virtual reality (VR) based experimental setup to monitor and modify the neural and physiological anxiety-related responses to balance-demanding target-reaching whole body leaning tasks. In our system, electroencephalography (EEG) and electrocardiography (EKG) signals are used to analyze the subjects...

We describe an experimental setup, which uses virtual reality to understand neural responses to height and perturbations in human postural control. This system could help clinicians develop better methods to alleviate symptoms from a significant fear of heights, especially in the elderly and those with movement disorders, such as Parkinson's diseas...

Multiple Sclerosis (MS), an autoimmune and demyelinating disease, is one the most prevalent neurological disabilities in young adults. It results in damage of the central nervous system, disrupting communication between the patient's brain, spinal cord and body. Mobility limitations is one of the earliest symptoms and affects a majority of persons...

Functional near-infrared spectroscopy was used to evaluate prefrontal cortex activation differences between older adults with multiple sclerosis (MS) and healthy older adults (HOA) during the performance of a balance- and attention-demanding motor task. Ten older adults with MS and 12 HOA underwent functional near-infrared spectroscopy recording wh...

The objective of this study was to examine the effects of aerobic fitness on cognitive performance under varying dual-task demands in older adults. Thirty-four participants (mean ± SD age: 68.6 ± 10.1 years, 24 females) were included in this study. VO2 max was assessed with the Rockport 1-mile walk test (range = 6.68–45.57). Participants engaged in...

We outline an experimental setup designed to dynamically understand neural responses to visual cliffs while walking. The goal of our work is understanding and mitigating fear of falling, particularly among the elderly. In our setup, an EEG cap monitors a subject’s neural activity while the subject is immersed in a virtual world and walking on an in...

Parkinson's disease is a prevalent and debilitating neurological disorder, where the severity of motor symptoms are frequently monitored using clinical tests that include a hand pronation and supination task. Objective quantification of motor symptoms in persons with Parkinson's disease and detection of dopamine-induced dyskinesias during treatment...

Background/Study Context: Although cognitive impairment is common in persons with multiple sclerosis (MS), there are limited data on older adults with MS. The current pilot study involved a preliminary examination of cognitive impairments across a comprehensive neuropsychological assessment in older adults with MS compared with older adults without...

Background: Gait impairments present while dual-tasking in older adults with multiple sclerosis (MS) have been associated with an increased risk of falls. Prior studies have examined prefrontal cortex (PFC) activity using functional near infrared spectroscopy (fNIRS) while dual-tasking in older adults with and without cognitive impairment. While t...

Background and purpose: There is a growing prevalence of older persons living with multiple sclerosis (MS), and this cohort likely undergoes changes in physical function associated with MS and its progression as well as those associated with normal aging. This cross-sectional study examined physical function in a community-dwelling sample of older...

Mobility and cognitive impairments are common in persons with multiple sclerosis (MS), and are expected to worsen with increasing age. However, no studies, to date, in part due to limitations of conventional neuroimaging methods, have examined changes in brain activation patterns during active locomotion in older patients with MS. This study used f...

Falls are a leading cause of injury and mortality among adults over the age of 65 years. Given the strong relation between fear of falling and fall risk, identification of the mechanisms that underlie anxiety-related changes in postural control may pave the way to the development of novel therapeutic strategies aimed at reducing fall risk in older...

There has been growing evidence showing gait variability provides unique information about gait characteristics in neurological disorders. This study systemically reviewed and quantitatively synthesized (via meta-analysis) existing evidence on gait variability in various neurological diseases, including Alzheimer's disease (AD), amyotrophic lateral...

The inability to maintain balance during varying postural control conditions can lead to falls, a significant cause of mortality and serious injury among older adults. However, our understanding of the underlying dynamical and stochastic processes in human postural control have not been fully explored. To further our understanding of the underlying...

We propose a time-domain approach to detect frequencies, frequency couplings, and phases using nonlinear correlation functions. For frequency analysis, this approach is a multivariate extension of discrete Fourier transform, and for higher-order spectra, it is a linear and multivariate alternative to multidimensional fast Fourier transform of multi...

Parkinson's disease (PD) is known to lead to marked alterations in cortical-basal ganglia activity that may be amenable to serve as a biomarker for PD diagnosis. Using non-linear delay differential equations (DDE) for classification of PD patients on and off dopaminergic therapy (PD-on, PD-off, respectively) from healthy age-matched controls (CO),...

The pathophysiology of Parkinson’s disease (PD) is known to involve altered patterns of neuronal firing and synchronization in cortical-basal ganglia circuits. We used delay differential equations (DDE) as non-linear time-domain classification tools to analyze electroencephalographic (EEG) recordings from PD patients on and off dopaminergic therapy...

Time series analysis with delay differential equations (DDEs) reveals non-linear properties of the underlying dynamical system and can serve as a non-linear time-domain classification tool. Here global DDE models were used to analyze short segments of simulated time series from a known dynamical system, the Rössler system, in high noise regimes. In...

We propose a time-domain approach to detect cross-trial frequencies based on nonlinear correlation functions. This method is a multivariate extension of discrete Fourier transform (DFT) and can be applied to short and/or sparse time series. Cross-trial and/or cross-channel spectra (CTS) can be obtained for electroencephalography (EEG) data where mu...

Falls are a significant cause of mortality and serious injury in older adults and particularly in people with neurological disorders. The ability to maintain balance and postural control is commonly evaluated using center of pressure (COP) data collected with a force platform. Recent methods such as the Stabilogram Diffusion Analysis (SDA) have exa...

The effect of Parkinson's disease on hand-eye coordination and corrective response control during reach-to-grasp tasks remains unclear. Moderately impaired Parkinson's disease patients (PD, n=9) and age-matched controls (n=12) reached to and grasped a virtual rectangular object, with haptic feedback provided to the thumb and index fingertip by two...