Samuel Stuart

• PhD Neuroscience, MSc Physiotherapy, BSc (Hons) Sport and Exercise Science
• Director at Novartis

Gait impairment is a core feature of Parkinson's disease (PD) which has been linked to cognitive and visual deficits, but interactions between these features are poorly understood. Monitoring saccades allows investigation of real-time cognitive and visual processes and their impact on gait when walking. This study explored; 1) saccade frequency whe...

An emerging body of literature has examined cortical activity during walking and balance tasks in older adult and Parkinson’s disease (PD) participants, specifically using functional near infrared spectroscopy (fNIRS) or electroencephalography (EEG) devices. This review aimed to provide an overview of this developing area, in order to inform diseas...

Introduction: Mobility declines with age and further with neurodegenerative disorders, such as Parkinson's disease (PD). Walking and turning ability, in particular, are vital aspects of mobility that deteriorate with age and are further impaired in PD. Such deficits have been linked with reduction in automatic control of movement and the need for c...

Background and Purpose: Gait and turning impairments are common in people with Parkinson disease (PwPD). Tactile cues delivered in open or closed-loop modalities may improve gait and turning in PwPD, but the underlying mechanisms are unclear. Evidence suggests attention stemming from the pre-frontal cortex (PFC) may play a role in cue response, but...

Background Gait impairments are common in Parkinson’s disease (PD) and increase falls risk. Visual cues can improve gait in PD, particularly freezing of gait (FOG), but mechanisms involved in visual cue response are unknown. This study aimed to examine brain activity in response to visual cues in people with PD who do (PD+FOG) and don’t report FOG...

Parkinson’s disease (PD) can cause postural instability, which may result in falls. These issues have been associated with motor and non-motor symptoms (NMS), including cognitive dysfunction. Several techniques have been employed to investigate the underlying neural mechanisms involved in postural control in PD. These include behavioural studies as...

Digital technologies have a critical role to play in contemporary sporting contexts by aiding performance and reducing injury. Indeed, digital technologies have become commonplace in professional sports, with organisations investing financial and time resources to accurately and reliably quantify training and competition characteristics to obtain a...

Ocular microtremor (OMT) is a fixational eye movement that cannot be seen with the naked eye but is always present, even when the eye appears motionless/still. The link between OMT and brain function provides a strong rationale for investigation as there lies potential for its use as a biomarker in populations with neurological impairments. OMT fre...

The analysis of running gait has conventionally taken place within an expensive and restricted laboratory space, with wearable technology offering a practical, cost-effective, and unobtrusive way to examine running gait in more natural environments. This pilot study presents a wearable inertial measurement unit (IMU) setup for the continuous analys...

Background There is currently no pharmacological treatment for visuo-cognitive impairments in Parkinson’s disease. Alternative strategies are needed to address these non-motor symptoms given their impact on quality of life. Novel technologies have potential to deliver multimodal rehabilitation of visuo-cognitive dysfunction, but more research is re...

Eye movement assessment is a key component of neurological evaluation, offering valuable insights into neural deficits and underlying mechanisms. This narrative review explores the emerging subject of digital eye-movement outcomes (DEMOs) and their potential as sensitive biomarkers for neurological impairment. Eye tracking has become a useful metho...

Inertial Measurement Units (IMUs) have emerged as popular tools for gait related fall risk analysis due to their low cost, portability, and ability to capture spatial and temporal gait characteristics (e.g., step length and step time, respectively). Free-living analysis using IMUs is an unobtrusive means for wearers to perform daily activities with...

Research investigating aging and neurological disorders that affect gait and balance aim to increase the understanding of the underlying neural mechanisms involved in task performance. Traditional brain-imaging techniques are restricted in their use in studies assessing brain activity during real-time balance and walking tasks, often restrained to...

Many neurological conditions result in balance dysfunction, increasing the risk of falls and fall-related injuries in these populations. Compared to more obvious mobility issues such as gait difficulty, balance impairments may be more subtle, requiring sensitive tests to be observable or quantified, particularly at the early stages of these disorde...

Running biomechanics have traditionally been analysed in laboratory settings, but this may not reflect natural running gait. Wearable technology has the potential to enable precise monitoring of running gait beyond the laboratory. This study aimed to evaluate the analytical validity and intra-session reliability of temporal running gait outcomes me...

The study provides a novel insight into the sensorimotor neural correlates of backwards walking compared to forward walking, using mobile EEG, in individuals with mild to moderate Parkinson's Disease.

Purpose: To evaluate the usability and acceptability of a free, tablet-based application “Keep on Keep Up” (KOKU) for people with Parkinson’s. KOKU is a tablet-based strength and balance exercise programme that incorporates the safety features and progressive intensity levels of the evidence-based Otago Exercise Program. KOKU has been specifically...

Objective: Parkinson’s disease (PD) is characterized by gait impairments, impacting patient mobility and quality of life. This study compares a reference gait measurement system, GAITRite (GR) against digital insoles, Moticon ReGo (MR), for measuring spatial and temporal gait characteristics in PD patients, with potential as indicators of disease p...

This review examined literature that has examined mobility in pulmonary arterial hypertension (PAH) using digital technology. Specifically, the review focussed on: (a) digital mobility measurement in PAH; (b) commonly reported mobility outcomes in PAH; (c) PAH specific impact on mobility outcomes; and (d) recommendations concerning protocols for mo...

Contemporary research to better understand free-living fall risk assessment in Parkinson’s disease (PD) often relies on the use of wearable inertial-based measurement units (IMUs) to quantify useful temporal and spatial gait characteristics (e.g., step time, step length). Although use of IMUs is useful to understand some intrinsics PD fall-risk fac...

Background Walking abnormalities in people with Parkinson’s disease (PD) are characterized by a shift in locomotor control from healthy automaticity to compensatory, executive control, mainly located in the prefrontal cortex (PFC). Although PFC activity during walking increases in people with PD, the time course of PFC activity during walking and i...

Falls are a major concern for people with Parkinson's disease (PwPD), but accurately assessing real world falls risk beyond the clinic is challenging. Contemporary technologies could enable the capture of objective and high-resolution data to better inform falls risk through measurement of everyday factors (e.g., obstacles) that contribute to falls...

Systems and techniques disclosed herein include receiving static device data in response to detected first biometric movements, receiving mobile device data in response to detected second biometric movements, applying an analysis algorithm to the static data to determine static attributes, applying the analysis algorithm to the mobile data to deter...

Background Falls are common in a range of clinical cohorts, where routine risk assessment often comprises subjective visual observation only. Typically, observational assessment involves evaluation of an individual’s gait during scripted walking protocols within a lab to identify deficits that potentially increase fall risk, but subtle deficits may...

OBJECTIVE: Vestibular/ocular deficits occur with mild traumatic brain injury (mTBI). The vestibular/ocular motor screening (VOMS) tool is used to assess individuals post-mTBI, which primarily relies upon subjective self-reported symptoms. Instrumenting the VOMS (iVOMS) with technology may allow for more objective assessment post-mTBI, which reflect...

Gait is impaired in musculoskeletal conditions, such as knee arthropathy. Gait analysis is used in clinical practice to inform diagnosis and to monitor disease progression or intervention response. However, clinical gait analysis relies on subjective visual observation of walking, as objective gait analysis has not been possible within clinical set...

Lack of physical activity is a global issue for adults that can lead to sedentary behaviour and a higher prevalence of health complications and chronic diseases, resulting in reduced quality-of-life (QoL) and functional capacity (FC). A potential strategy to mitigate this inactivity is low-dose resistance training (RT); however, physiological, and...

Background Concussions result in transient symptoms stemming from a cortical metabolic energy crisis. Though this metabolic energy crisis typically resolves in a month, symptoms can persist for years. The symptomatic period is associated with gait dysfunction, the cortical underpinnings of which are poorly understood. Quantifying prefrontal cortex...

Poster presentation of a systematic literature review of neural correlates of balance in people with Parkinson's disease.

Wearable inertial measurement units (IMUs) are being used to quantify gait characteristics that are associated with increased fall risk, but the current limitation is the lack of contextual information which would clarify IMU data. Use of wearable video-based cameras would provide a comprehensive understanding of an individual’s habitual fall risk,...

Objective SRC diagnosis utilises clinical judgement [1–3], and is often supported by the Sports Concussion Assessment Tool (SCAT5). The use of pragmatic accessible/scalable digital tools may improve diagnosis and understanding of interconnected relationships in SRC deficits [4–7]. Our aim was to explore comparison of SCAT5 outcomes to digital tools...

Purpose: The subjective nature of the Sports Concussion Assessment Tool (SCAT5), means SRC diagnosis is based on clinical judgment, with focus given to symptom resolution to determine readiness to play, which may hinder understanding of the interconnected nature and relationships in deficit recovery. Here we investigate results from an experimental...

Instrumented gait through objective data is important in clinical rehabilitation as it provides objective mobility assessment. Typically, those data help pinpoint the root causes of mobility impairments, subsequently enabling the foundation for the development of effective rehabilitation protocols/programs. Inertial sensors-based wearables such as...

Objective: Gait assessments have traditionally been analysed in laboratory settings, but this may not reflect natural gait. Wearable technology may offer an alternative due to its versatility. The purpose of the study was to establish the validity and reliability of temporal gait outcomes calculated by the DANU Sports System, against a 3D motion c...

Background Visual cues can improve gait in Parkinson’s disease (PD), including those experiencing freezing of gait (FOG). However, responses are variable and underpinning mechanisms remain unclear. Visuo-cognitive processing (measured through visual exploration) has been implicated in cue response, but this has not been comprehensively examined. O...

Quantitative running gait analysis is an important tool that provides beneficial outcomes to injury risk/recovery or performance assessment. Wearable devices have allowed running gait to be evaluated in any environment (i.e., laboratory or real-world settings), yet there are a plethora of different grades of devices (i.e., research-grade, commercia...

Objective: To examine the cortical control of gait and balance in HD under single-task (ST) and dual-task (DT) conditions compared to healthy controls using portable functional near infrared spectroscopy (fNIRS). Background: Individuals with Huntington’s disease (HD) have difficulty multitasking while navigating their environment, so that previous...

Objective: To determine the feasibility and preliminary efficacy of a home-based, technological visuo-cognitive training (TVT) intervention using a mobile application and exercise with stroboscopic glasses compared to standard care in people with Parkinson’s disease (PD). Background: There is currently no pharmacological treatment for visuo-cognit...

Objective: This study aims to examine OMT in people with PD (PwPD) compared to healthy older adults. Identifying OMT as a PD biomarker could better support clinical assessment, enabling improved provision of care to patients with advanced disease monitoring. Background: Ocular microtremor (OMT) is a fixational eye movement that cannot be seen with...

Ocular microtremor (OMT) is the smallest of three involuntary fixational micro eye movements, which has led to it being under researched in comparison. The link between OMT and brain function generates a strong rationale for further study as there is potential for its use as a biomarker in populations with neurological injury and disease. This stru...

Visual problems are common in people who have neurological injury or disease, with deficits linked to postural control and gait impairment. Vision therapy could be a useful intervention for visual impairment in various neurological conditions such as stroke, head injury, or Parkinson’s disease. Stroboscopic visual training (SVT) has been shown to i...

Gait speed declines with age and slower walking speeds are associated with poor health outcomes. Understanding why we do not walk faster as we age, despite being able to, has implications for rehabilitation. Changes in regional oxygenated haemoglobin (HbO2) across the frontal lobe were monitored using functional near infrared spectroscopy in 17 you...

Fall risk assessment can be informed by understanding mobility/gait. Contemporary mobility analysis is being progressed by wearable inertial measurement units (IMU). Typically, IMUs gather temporal mobility-based outcomes (e.g., step time) from labs/clinics or beyond, capturing data for habitually informed fall risk. However, a thorough understandi...

Background: Cognitive impairment is a common non-motor feature of Parkinson’s disease (PD). Mobile applications delivering multidomain cognitive rehabilitation offer a potential means of delaying the worsening of cognitive deficits, but evidence for their feasibility of implementation in people with PD is limited. Aim: This pilot study evaluated th...

Ocular microtremor (OMT) is a fixational eye movement that cannot be seen with the naked eye but is always present, even when the eye appears motionless/still. The link between OMT and brain function generates a strong rationale for investigation as there lies potential for its use as a biomarker in populations of neurological impairments. OMT freq...

Background Mobile applications and technology (e.g., stroboscopic glasses) are increasingly being used to deliver combined visual and cognitive (termed visuo-cognitive) training that replaces standard pen and paper-based interventions. These ‘technological visuo-cognitive training’ (TVT) interventions could help address the complex problems associa...

Unlabelled: Although the multifactorial nature of falls in Parkinson's disease (PD) is well described, optimal assessment for the identification of fallers remains unclear. Thus, we aimed to identify clinical and objective gait measures that best discriminate fallers from non-fallers in PD, with suggestions of optimal cutoff scores. Methods: Ind...

Walking/gait quality is a useful clinical tool to assess general health and is now broadly described as the sixth vital sign. This has been mediated by advances in sensing technology including instrumented walkways and three-dimensional motion capture. However, it is wearable technology innovation that has spawned the utmost growth in instrumented...

Aging is a key risk factor for the development of Parkinson's Disease (PD). PD is characterized by excessive synchrony of beta oscillations (13-30 Hz) in the basal ganglia thalamo-cortical network. However, cortical beta power is not reliably elevated in individuals with PD. Here, we sought to disentangle how resting cortical beta power compares in...

Advancements in Microelectromechanical systems (MEMS) have enabled the manufacture of affordable and efficient wearable devices. In sensor-based gait analysis, motion and biofeedback sensor devices are easily attached to different parts of the body. Instrumentation of gait using different sensor technologies enables researchers and clinicians to ca...

Fall risk assessment needs contemporary approaches based on habitual data. Currently, inertial measurement unit (IMU) based wearables are used to inform free-living spatio-temporal gait characteristics to inform mobility assessment. Typically, a fluctuation of those characteristics will infer an increased fall risk. However, current approaches with...

Running gait assessment is essential for development of technique optimization strategies as well as to inform injury prevention and rehabilitation. Currently, running gait assessment relies on (i) visual assessment, exhibiting subjectivity and limited reliability, or (ii) use of instrumented approaches, which often carry high costs and can be intr...

Inertial sensor-based human activity recognition (HAR) has a range of healthcare applications as it can indicate overall health status or functional capabilities of people with impaired mobility. Typically, artificial intelligence models achieve high recognition accuracies when trained with rich and diverse inertial datasets. However, obtaining suc...

Background: Turning is a complex measure of gait that accounts for over 50% of daily steps. Traditionally, turning has been measured in a research grade la-boratory setting, however, there is demand for a low-cost and portable solution to measure turning using wearable technology. This study aimed to determine the suitability of a low-cost inertial...

Various cueing strategies (internal and external) have been used to alleviate gait deficits in Parkinson’s disease (PD). However, it remains unclear which type of cueing strategy is most effective at different disease stages or with more severe walking impairment, such as freezing of gait (FOG). The underlying neural mechanisms of response to cuein...

We previously showed that both open-loop (beat of a metronome) and closed-loop (phase-dependent tactile feedback) cueing may be similarly effective in reducing Freezing of Gait (FoG), assessed with a quantitative FoG Index, while turning in place in the laboratory in a group of people with Parkinson’s disease (PD). Despite the similar changes on th...

Exploring the practicality and feasibility of multimodal Sports Related Concussion (SRC) assessments compared to the reference standard (SCAT5) in university athletes. Significant challenges remain in the monitoring and assessment of suspected Sports Related Concussion (SRC). The most commonly used mechanism within amateur sports, is the 5th versi...

Background Running gait assessment has traditionally been performed using subjective observation or expensive laboratory-based objective technologies, such as 3D motion capture or force plates. However, recent developments in wearable devices allow for continuous monitoring and analysis of running mechanics in any environment. Objective measurement...

Visual and cognitive dysfunction are common in Parkinson’s disease and relate to balance and gait impairment, as well as increased falls risk and reduced quality of life. Vision and cognition are interrelated (termed visuo-cognition) which makes intervention complex in people with Parkinson’s (PwP). Non-pharmacological interventions for visuo-cogni...

Mild traumatic brain injury (mTBI or concussion) is receiving increased attention due to the incidence in contact sports and limitations with subjective (pen and paper) diagnostic approaches. If an mTBI is undiagnosed and the athlete prematurely returns to play, it can result in serious short-term and/or long-term health complications. This demonst...

Introduction: Following mild traumatic brain injury (mTBI), patients are often advised to restrict physical activity until full symptom resolution followed by gradual return to activity. However, extended rest periods may prolong recovery and contribute to persistent symptoms. Emerging evidence suggests early active rehabilitation that increases he...

Objective: To examine the neural activity during turning in Parkinson’s disease (PD). Background: Turning is impaired in PD with links to freezing of gait (FOG) and falls risk. Specifically, turning is slow and elicits FOG episodes in PD, which can be worsened by performing a secondary task when turning (i.e., dual-tasking). The neural mechanism...

Objective: To explore experiences of people with Parkinson’s (PwP) in using technology as part of a home-based visuo-cognitive training programme compared to traditional approaches to rehabilitation. Background: Visual and cognitive dysfunction are common in PwP, and relate to mobility impairment and increased falls risk. Novel technologies and mo...

Turning is a common impairment of mobility in people with Parkinson’s disease (PD), which increases freezing of gait (FoG) episodes and has implications for falls risk. Visual cues have been shown to improve general gait characteristics in PD. However, the effects of visual cues on turning deficits in PD remains unclear. We aimed to (i) compare the...

Gait assessment is essential to understand injury prevention mechanisms during running, where high-impact forces can lead to a range of injuries in the lower extremities. Information regarding the running style to increase efficiency and/or selection of the correct running equipment, such as shoe type, can minimize the risk of injury, e.g., matchin...

Postural control involves hierarchical coordination of sensorimotor circuits mediated through automatic, subcortical mechanisms and top-down cortical mechanisms. Cortical involvement in balance and gait has traditionally been inferred indirectly, through degradation in performance during a cognitive task. Direct measures of brain activity during ba...

Contemporary approaches to gait assessment use wearable devices within free-living environments to capture habitual information, which is more informative compared to data capture in the lab. Wearables range from inertial to camera-based technologies but pragmatic challenges such as analysis of big data from heterogenous environments exist. For exa...

The objective of this systematic review is to investigate the effects of different methods of resistance training (RT) on functional capacity in older adults. A systematic literature search was conducted using PubMed, SPORTDiscus, Web of Science, CINAHL, Cochrane CENTRAL, ClinicalTrials.gov databases, from inception to December 2021. Eligibility cr...

BACKGROUND & AIM: Sports-Related Concussion (SRC) encompasses symptom, visual, cognitive and motor impairments, where accurate and timely recognition is crucial to reduce incidences of misdiagnosis, which can increase morbidity risk [1]. Yet current non-digital tools, e.g Sports Concussion Assessment Tool (SCAT5) criteria [2] relies on symptom reso...

Background and aim: The study of the neural underpinnings of movement in neurological conditions has traditionally been conducted with associative studies that have used static imaging techniques, such as functional magnetic resonance imaging or positron emission tomography. Previous work correlated movement outcomes with imaging or assessed ass...

Running gait assessment and running shoe recommendation is important for the injury prevention of runners who exhibit different skill-levels and running styles. Traditionally, running gait assessment for shoe recommendation relies upon a combination of trained professionals (e.g., sports-therapists, physiotherapists) and complex equipment such as m...

This volume explores the latest eye-tracking methodologies that help researchers understand the background, methods, and applications involved in these studies. The chapters in this book cover topics such as methods and models of eye-tracking in natural environments; natural gaze informatics (i.e., assisted wheelchair mobility); eye-tracking applic...

Eye movements are an important aspect of neurological clinical assessment, as abnormal eye movements can indicate underlying neurological and disease processes. Eye-tracking recordings are also often performed following neurological injury or disease in order to study the underlying neurological mechanisms involved in controlling eye movement. The...