159 research outputs found

    A novel behavioural paradigm for characterising anticipatory postural adjustments in mice

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    Daily we use purposeful, voluntary movements to interact with our environment. These movements demand and cause our body to experience a weight redistribution, i.e., anticipatory postural adjustments (APAs), and it’s the appropriate employment of these APAs that allows us to complete said voluntary movements without falling over or losing our equilibrium. The literature suggests that for humans, monkeys, and several quadrupeds, APAs are crucial at initiation and during movement. However, research has been somewhat limited due to the lack of behavioural paradigms that would allow for a better understanding into the neural circuitry involved with APAs. Given the widespread availability of genetic tools and advanced viral techniques in mice I focused my efforts in developing a novel behavioral paradigm for this species. The first chapters detail the reasoning behind the development of this novel behavioural paradigm while also providing a complete description of the different components and their functions. Later chapters use the custom-designed setup to characterise mouse APAs, incorporating various recording approaches designed to quantify APAs and compare them to those described in prior work, highlighting possible interspecifies similarities and differences. Additionally, I briefly discuss the potential neural circuitry of APAs informed by my own data and research that has been done in different animals, providing a comprehensive overview of APAs in mice

    Assessment of Physical Activity in Adults with Progressive Muscle Disease

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    Introduction: Insufficient physical activity is a major threat to global health. Physical activity benefits peoples’ physical and mental health. The general population, including people living with disabilities and muscle wasting conditions, are recommended to avoid excessive sedentary time and engage in daily activity. Adults with progressive muscle disease experience barriers to physical activity participation, including muscle weakness, fatigue, physical deconditioning, impairment, activity limitations and participation restrictions (including societal and environmental factors), and fear of symptom exacerbation. More research is required to understand the inter-relationship between health and physical activity for adults with progressive muscle disease, particularly non-ambulant people who are under-represented in the existing research literature. Accurate measurement of FITT (frequency, intensity, time, and type of physical activity) is vital for high-quality physical activity assessment. The aim of this thesis was to assess the physical activity of ambulant and non-ambulant adults with progressive muscle disease.Systematic review findings identified various measures used to assess physical activity in adults with muscular dystrophy, including accelerometers, direct observation, heart rate monitors, calorimetry, positioning systems, activity diaries, single scales, interviews and questionnaires. None of the measures identified in the systematic review had well established measurement properties for adults with muscular dystrophy.Patient and public involvement interviews highlighted the importance of inclusive, remote, and technology-facilitated research design, the potential intrusion of direct observations of physical activity, the familiarity of questionnaires for data collection, and practical considerations to ensure wearing an activity monitor was not too burdensome.A feasibility study using multiple methods in 20 ambulant and non-ambulant adults with progressive muscle disease revealed satisfactory acceptability, interpretability, and usability of Fitbit and activity questionnaires, in both paper and electronic formats. During supervised activity tasks, Fitbit was found to have satisfactory criterion validity, reliability, and responsiveness and measurement properties were strengthened using multisensory measurement.An observational, longitudinal study that included 111 ambulant and non-ambulant adults with progressive muscle disease showed that:Activity monitoring had satisfactory validity, reliability and responsiveness using Fitbit, but there was considerable measurement error between Fitbit and the research grade GENEActiv accelerometer. Fitbit thresholds and multiple metrics (including accelerometer and heart rate data extrapolations of FITT) were appropriate for physical activity assessment in ambulant and non-ambulant adults with progressive muscle disease.Activity self-report had unsatisfactory concurrent validity, test-retest reliability, and responsiveness with substantial activity overestimation using the modified International Physical Activity Questionnaire. However, self-report properties were improved when used concurrently with Fitbit.Observed physical activity in adults with progressive muscle disease was generally low with excessive daily sedentary time. Activity frequencies, intensities and durations were lower, and activity types were more domestic, for wheelchair users and during the COVID-19 lockdown. Lower physical activity was significantly associated with greater functional impairment, less cardiorespiratory fitness, worse metabolic health, and lower quality of life. Activity optimisation thresholds and minimal clinically important differences were established.Discussion: The implications of this thesis include guidance for selection of appropriate physical activity measures by clinicians and researchers working with adults with progressive muscle disease. Fitbit is suitable in clinical practice and research for interactive, weekly remote activity monitoring or to support activity self-management and may represent an appropriate compromise between potential underestimation by accelerometry alone, and overestimation by self-report alone. A draft conceptual framework for physical activity measurement was also proposed. It includes frequency, intensity, time, and type of physical activity, and incorporates wider aspects of the physical activity construct, including somatic factors (relating to progressive muscle disease and underlying fitness) and contextual factors (relating to personal, social, and environmental situations). Future research will build on the knowledge gained in this thesis, furthering understanding of the inter-relationships between physical activity, health and wider contexts. Implementation will include testing a remote physical activity optimisation intervention that is inclusive of ambulant and non-ambulant participants, featuring Fitbit self-monitoring with a focus on optimisation of daily activity frequency and regularly interrupting sedentary time.</div

    Proceedings XXIII Congresso SIAMOC 2023

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    Il congresso annuale della Società Italiana di Analisi del Movimento in Clinica (SIAMOC), giunto quest’anno alla sua ventitreesima edizione, approda nuovamente a Roma. Il congresso SIAMOC, come ogni anno, è l’occasione per tutti i professionisti che operano nell’ambito dell’analisi del movimento di incontrarsi, presentare i risultati delle proprie ricerche e rimanere aggiornati sulle più recenti innovazioni riguardanti le procedure e le tecnologie per l’analisi del movimento nella pratica clinica. Il congresso SIAMOC 2023 di Roma si propone l’obiettivo di fornire ulteriore impulso ad una già eccellente attività di ricerca italiana nel settore dell’analisi del movimento e di conferirle ulteriore respiro ed impatto internazionale. Oltre ai qualificanti temi tradizionali che riguardano la ricerca di base e applicata in ambito clinico e sportivo, il congresso SIAMOC 2023 intende approfondire ulteriori tematiche di particolare interesse scientifico e di impatto sulla società. Tra questi temi anche quello dell’inserimento lavorativo di persone affette da disabilità anche grazie alla diffusione esponenziale in ambito clinico-occupazionale delle tecnologie robotiche collaborative e quello della protesica innovativa a supporto delle persone con amputazione. Verrà infine affrontato il tema dei nuovi algoritmi di intelligenza artificiale per l’ottimizzazione della classificazione in tempo reale dei pattern motori nei vari campi di applicazione

    Exercise-Induced Hypoalgesia in people with chronic low back pain

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    Chronic low back pain (CLBP) is one of the most prevalent musculoskeletal disorders and a major contributor to disability worldwide. Exercise is recommended in guidelines as a cornerstone of the management of CLBP. One of the manifold benefits of exercise is its influence on endogenous pain modulation. An acute bout of exercise elicits a temporary decrease in pain sensitivity, described as exercise-induced hypoalgesia (EIH). This thesis explores EIH in people with CLBP via a systematic review and observational studies. The systematic review included 17 studies in people with spinal pain. Of those, four studies considered people with CLBP revealing very low quality evidence with conflicting results. EIH was elicited following remote cycling tasks (two studies, fair risk of bias), but EIH was altered following local repetitive lifting tasks (two studies, good/fair risk of bias). The observational studies investigated EIH following three different tasks in participants with and without CLBP and explored the stability of EIH results. Conflicting results from quantitative sensory testing were found for whether EIH is impaired in people with CLBP. EIH was only elicited in asymptomatic participants following a repeated lifting task, but both participants with and without CLBP showed EIH following a lumbar resistance and a brisk walking task. This thesis demonstrates the first evidence of stability of EIH over multiple sessions. However, the interpretation of the results can be challenging as stability was poor and changes in lumbar pressure pain thresholds also occurred after rest only. These findings are important to inform future studies contributing to the elucidation of the complex phenomenon of EIH in people with/without CLBP, specifically as the stability is a prerequisite for future research

    Bilateral Prefrontal Cortex Activation During Ankle Sensorimotor Conditions in People with Subacute Stroke – an Exploratory fNIRS Study

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    The purpose of this exploratory study is to evaluate prefrontal cortex (PFC) activation patterns linked to active and passive paretic ankle dorsiflexion and plantarflexion and somatosensory stimulation (SS) using a reformed paperclip in people with subacute stroke. By using a neuroimaging tool called functional near-infrared spectroscopy (fNIRS) over the PFC, oxygenated and deoxygenated hemoglobin levels were collected in 9 participants. Objectives, including between-condition differences in PFC activation, interhemispheric asymmetry during conditions, and the relationship between interhemispheric asymmetry and clinical outcome measurement (Fugl-Meyer Lower Extremity Assessment, or FMLE), were evaluated using the fNIRS plots and Laterality Index (LI). Results showed that the active condition demonstrated the highest PFC activation, followed by the SS condition, then the passive condition. Two methods (LI and fNIRS plots) investigated interhemispheric asymmetry and divergent findings were found. Moreover, participants who have a higher score on the FMLE demonstrated bilateral PFC activation during active and SS conditions but contralesional activation during the passive condition. Overall, our study provided exploratory results that assist in understanding the role of PFC in ankle sensorimotor functions in people with subacute stroke

    Novel Bidirectional Body - Machine Interface to Control Upper Limb Prosthesis

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    Objective. The journey of a bionic prosthetic user is characterized by the opportunities and limitations involved in adopting a device (the prosthesis) that should enable activities of daily living (ADL). Within this context, experiencing a bionic hand as a functional (and, possibly, embodied) limb constitutes the premise for mitigating the risk of its abandonment through the continuous use of the device. To achieve such a result, different aspects must be considered for making the artificial limb an effective support for carrying out ADLs. Among them, intuitive and robust control is fundamental to improving amputees’ quality of life using upper limb prostheses. Still, as artificial proprioception is essential to perceive the prosthesis movement without constant visual attention, a good control framework may not be enough to restore practical functionality to the limb. To overcome this, bidirectional communication between the user and the prosthesis has been recently introduced and is a requirement of utmost importance in developing prosthetic hands. Indeed, closing the control loop between the user and a prosthesis by providing artificial sensory feedback is a fundamental step towards the complete restoration of the lost sensory-motor functions. Within my PhD work, I proposed the development of a more controllable and sensitive human-like hand prosthesis, i.e., the Hannes prosthetic hand, to improve its usability and effectiveness. Approach. To achieve the objectives of this thesis work, I developed a modular and scalable software and firmware architecture to control the Hannes prosthetic multi-Degree of Freedom (DoF) system and to fit all users’ needs (hand aperture, wrist rotation, and wrist flexion in different combinations). On top of this, I developed several Pattern Recognition (PR) algorithms to translate electromyographic (EMG) activity into complex movements. However, stability and repeatability were still unmet requirements in multi-DoF upper limb systems; hence, I started by investigating different strategies to produce a more robust control. To do this, EMG signals were collected from trans-radial amputees using an array of up to six sensors placed over the skin. Secondly, I developed a vibrotactile system to implement haptic feedback to restore proprioception and create a bidirectional connection between the user and the prosthesis. Similarly, I implemented an object stiffness detection to restore tactile sensation able to connect the user with the external word. This closed-loop control between EMG and vibration feedback is essential to implementing a Bidirectional Body - Machine Interface to impact amputees’ daily life strongly. For each of these three activities: (i) implementation of robust pattern recognition control algorithms, (ii) restoration of proprioception, and (iii) restoration of the feeling of the grasped object's stiffness, I performed a study where data from healthy subjects and amputees was collected, in order to demonstrate the efficacy and usability of my implementations. In each study, I evaluated both the algorithms and the subjects’ ability to use the prosthesis by means of the F1Score parameter (offline) and the Target Achievement Control test-TAC (online). With this test, I analyzed the error rate, path efficiency, and time efficiency in completing different tasks. Main results. Among the several tested methods for Pattern Recognition, the Non-Linear Logistic Regression (NLR) resulted to be the best algorithm in terms of F1Score (99%, robustness), whereas the minimum number of electrodes needed for its functioning was determined to be 4 in the conducted offline analyses. Further, I demonstrated that its low computational burden allowed its implementation and integration on a microcontroller running at a sampling frequency of 300Hz (efficiency). Finally, the online implementation allowed the subject to simultaneously control the Hannes prosthesis DoFs, in a bioinspired and human-like way. In addition, I performed further tests with the same NLR-based control by endowing it with closed-loop proprioceptive feedback. In this scenario, the results achieved during the TAC test obtained an error rate of 15% and a path efficiency of 60% in experiments where no sources of information were available (no visual and no audio feedback). Such results demonstrated an improvement in the controllability of the system with an impact on user experience. Significance. The obtained results confirmed the hypothesis of improving robustness and efficiency of a prosthetic control thanks to of the implemented closed-loop approach. The bidirectional communication between the user and the prosthesis is capable to restore the loss of sensory functionality, with promising implications on direct translation in the clinical practice

    A critical appraisal of research in arts, health and wellbeing

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    In interviews study participants stated the importance of the arts, its value, and the contribution to improve their ... This review considered wellbeing as reported in the included studies at the individual and community levels

    Individuality in balance control: Using conventional analytical & machine learning approaches to reveal person-specific differences in standing balance control.

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    The balance control system ensures that humans can perform tasks in a variety of postures despite bipedal stance being inherently unstable. It manages this instability by producing motor outputs that are appropriate to sensory input given the objective of maintaining balance. An inability to maintain this balance may result in a fall which can have both short and long-term physical, psychological, and social effects. The ability to maintain balance is a strong predictor of fall-risk and mobility limitations. Falling has been associated with specific populations such as older adults and those with neurological and neuromuscular pathologies. However, it is possible that some younger individuals may have poor balance control which places them at a greater fall-risk in the face of age and pathology-related influences. The potential importance of revealing person-specific differences in balance control in healthy, young adults has led to the focus of this thesis. This thesis was designed to determine whether a healthy, young adult’s balance control system, as measured by their balance performance, is specific to the individual and could be distinguished from any other individual. The thesis explores the use of different methods of measuring of body movement (kinetic or kinematic), and the analytical techniques which, when collectively applied, may more sensitively reveal these individual differences. General methodology consisted of sixty-one healthy, young adults (ages 18-35), free of any neurological or neuromuscular disorders, performing a series of static standing balance trials. Four task conditions, Base of Support (standard and narrow) and Vision (open and closed), were performed five times, each for thirty seconds. Balance performance was measured kinetically using two floor-mounted force plates, and kinematically using three inertial measurement units placed on the head, sternum, and lumbar region of the back. The resulting data became the substrate for the analyses used in the three studies. Study 1 quantified the consistency of an individual’s balance performance across task conditions relative to the other individuals. Centre-of-pressure data collected from force plates was analyzed using established linear and non-linear analytical methods within the time- and frequency-domains and then input into a linear mixed-effects model. Subject-specific factors, such as anthropometrics and vision quality, were controlled to reduce the number of confounding variables. Correlational analysis of the random-effect, participant, revealed moderate to strong correlations of individual balance performances across task conditions with the strength of these correlations dependent on the analytical technique used. Study 1 confirmed that (1) task-related differences in balance performance could be detected by a variety of analytical techniques, and that (2) the correlations found in relative balance performance across task conditions suggest that an individuals’ balance control system may be specific to the individual. Study 2 expanded on Study 1 by representing body movement kinematically using body-worn inertial measurement units. Similar analytical approaches were used and moderate to excellent correlations in relative balance performance across task conditions were observed. The use of kinematic data in this study also revealed kinematic strategies that could only be obtained by modelling a person as a multi-link, rigid body and not as a single-link, inverted pendulum; an assumption commonly made when using kinetic data. Like Study 1, this work demonstrated that relative balance performance within persons were comparable across tasks of varying difficulty and, as such, indirectly supports the idea that balance control that may be specific to the individual. Study 3 focused on analytical approaches that could more directly reveal the unique features of balance control within individuals. This study employed a machine-learning, classification algorithm in an attempt to identify individuals by their balance performance using kinetic or kinematic measures. Once provided with the prototypical balance performances of a discrete number of individuals, the algorithm was able to correctly attribute the balance performance of a mystery person to one of those individuals with an accuracy greater that what could be achieved by random chance. Representing body movement with kinetic, time-series data yielded the highest accuracies (Accuracy (nway = 5) = 92.08%; Accuracy (nway = 20) = 74.69%). However, it is believed that if kinematic data was recorded with more fidelity, then even greater accuracies could be possible. Study 3 demonstrated that (1) balance performance data contains features specific to the individual which may quantitatively indicate individuality in the balance control system, and (2) that the ability to reveal this individuality is dependent on how the balance performance is represented. This thesis provided two main contributions, (1) support for the idea that balance control during quiet standing, as revealed through balance performance, contains features that are specific to the individual, and (2) an, outline, albeit preliminary, of the task conditions, methods of measurement, and analytical techniques best suited to reveal this individuality
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