BackgroundGait Analysis of healthy people, imitating pathological conditions while walking, has i... more BackgroundGait Analysis of healthy people, imitating pathological conditions while walking, has increased our understanding of biomechanical factors. The influence of the pelvis as a biomechanical constraint during gait is not specifically studied. How could mimicking a pelvic attitude influence the dynamic mechanical interaction of the body segments? We proposed an investigation of the pelvic attitude role on the gait pattern of typically developed people when they mimicked pelvic anteversion and posteroversion.Materials and methodsSeventeen healthy volunteers were enrolled in this study (mean age 24.4 ± 5.5). They simulated a pelvic anteversion and posteroversion during walking, exaggerating these postures as much as possible. 3D gait analysis was conducted using an optoelectronic system with eight cameras (Vicon MX, Oxford, United Kingdom) and two force plates (AMTI, Or-6, Watertown, MA, United States). The kinematic, kinetic, and spatio-temporal parameters were compared between ...
Background and Objective: Absolute angle represents the inclination of a body segment relative to... more Background and Objective: Absolute angle represents the inclination of a body segment relative to a fixed reference in space. This work compares the absolute and relative angles for exploring biomechanical gait constraints. Methods: Gait patterns of different neuromotor conditions were analyzed using 3D gait analysis: normal gait (healthy, H), Cerebral Palsy (CP), Charcot Marie Tooth (CMT) and Duchenne Muscular Dystrophy (DMD), representing central and peripheral nervous system and muscular disorders, respectively. Forty-two children underwent gait analysis: 10 children affected by CP, 10 children by CMT, 10 children by DMD and 12 healthy children. The kinematic and kinetic parameters were collected to describe the biomechanical pattern of participants' lower limbs. The absolute angles of thigh, leg and foot were calculated using the trigonometric relationship of the tangent. For each absolute series, the mean, range, maximum, minimum and initial contact were calculated. Kinematic and kinetic gait data were studied, and the results were compared with the literature. Results: Statistical analysis of the absolute angles showed how, at the local level, the single segments (thigh, leg and foot) behave differently depending on the pathology. However, if the lower limb is studied globally (sum of the kinematics of the three segments: thigh, leg and foot), a biomechanical constraint emerges. Conclusion: Each segment compensates separately for the disease deficit so as to maintain a global biomechanical invariance. Using a model of inter-joint co-variation could improve the interpretation of the clinical gait pattern.
The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well ... more The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well as its assessment and therapy. Cerebellar vermis is critical for postural control. The cerebellum ensures the mapping of sensory information into temporally relevant motor commands. Mental imagery of gait involves intrinsically connected fronto-parietal networks comprising the cerebellum. Muscular activities in cerebellar patients show impaired timing of discharges, affecting the patterning of the synergies subserving locomotion. Ataxia of stance/gait is amongst the first cerebellar deficits in cerebellar disorders such as degenerative ataxias and is a disabling symptom with a high risk of falls. Prolonged discharges and increased muscle coactivation may be related to compensatory mechanisms and enhanced body sway, respectively. Essential tremor is frequently associated with mild gait ataxia. There is growing evidence for an important role of the cerebellar cortex in the pathogenesis of essential tremor. In multiple sclerosis, balance and gait are affected due to cerebellar and spinal cord involvement, as a result of disseminated demyelination and neurodegeneration impairing proprioception. In orthostatic tremor, patients often show mild-to-moderate limb and gait ataxia. The tremor generator is likely located in the posterior fossa. Tandem gait is impaired in the early stages of cerebellar disorders and may be particularly useful in the evaluation of pre-ataxic stages of progressive ataxias. Impaired inter-joint coordination and enhanced variability of gait temporal and kinetic parameters can be grasped by wearable devices such as accelerometers. Kinect is a promising low cost technology to obtain reliable measurements and remote assessments of gait. Deep learning methods are being developed in order to help clinicians in the diagnosis and decision-making process. Locomotor adaptation is impaired in cerebellar patients. Coordinative training aims to improve the coordinative strategy and foot placements across strides, cerebellar patients benefiting from intense rehabilitation therapies. Robotic training is a promising approach to complement conventional rehabilitation and neuromodulation of the cerebellum. Wearable dynamic orthoses represent a potential aid to assist gait. The panel of experts agree that the understanding of the cerebellar contribution to gait control will lead to a better management of cerebellar ataxias in general and will likely contribute to use gait parameters as robust biomarkers of future clinical trials.
Background: Children with ataxia experience balance and movement coordination difficulties and ne... more Background: Children with ataxia experience balance and movement coordination difficulties and needs intensive physical intervention to maintain functional abilities and counteract the disorder. Exergaming represents a valuable strategy to provide engaging physical intervention to children with ataxia, sustaining their motivation to perform the intervention. This paper aims to describe the effect of a home-conducted exergame-based exercise training for upper body movements control of children with ataxia on their ataxic symptoms, walking ability, and hand dexterity. Methods: Eighteen children with ataxia were randomly divided into intervention and control groups. Participants in the intervention group were asked to follow a 12-week motor activity program at home using the Niurion® exergame. Blind assessments of participants’ ataxic symptoms, dominant and non-dominant hand dexterity, and walking ability were conducted. Results: On average, the participants performed the intervention ...
Background: It has been highlighted that obesity influences the gait reducing walking velocity, s... more Background: It has been highlighted that obesity influences the gait reducing walking velocity, stride length, ankle dorsal flexion at initial contact and ankle power generation. Meanwhile, step width, double support, hip flexion, knee extension during stance, hip moment and ankle power absorption was described increased. A tendency to the normalization of these parameters occur when subjects reduced their weight during growth. Objective: We studied the effect of fast weight loss due to Sleeve Gastrectomy on gait pattern of adolescent with severe obesity. The aim is to assess the functional benefit of the surgery. Setting: Pediatric hospital, public health, Italy. Methods: 11 patients before and after 1 year from surgery and 10 controls participated to the study. We studied the gait with an optoelectronic system and two force plates. We evaluated both kinetics and kinematics of walking. Then we looked at the differences between the pre-vs post-surgery and with the control group. Results: Step length and velocity were lower and step width was bigger in adolescent with obesity. Kinematic and kinetic parameters were altered. After surgery we observed the reduction of several gait alteration. Meanwhile, after 1 year alterations at the level of the foot, the knee and the pelvis persist. Conclusion: The sudden loss of weight highlighted the presence of long-term effects on the locomotor system. The results discourage intense walking activities before the weight loss and we suggest further studies for evaluating the necessity of a rehabilitative intervention.
Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest ... more Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest to improve motor control in different neurological diseases. Nanotechnology allowed the creation of wearable devices transforming thermal variations into mechanical energy with focal vibrations. This kind of wearable stimulators (WS) has produced encouraging preliminary results when used in the treatment of movement disorders and ataxia in adults. In this open label pilot study we first evaluated the feasibility, safety and effectiveness of NIFMV by WS in a cohort of 10 patients with childhood ataxia, a phenomenological category including different conditions still lacking of effective symptomatic therapies. Through the assessment of both clinical rating scales and spatio-temporal gait parameters via standardized gait analysis, we observed that a 4 weeks long treatment with WS Equistasi® was safe and provided significantly different effects in stride features of patients with slow/non-pr...
The speed of voluntary movements is determined by the conflicting needs of maximizing accuracy an... more The speed of voluntary movements is determined by the conflicting needs of maximizing accuracy and minimizing mechanical effort. Dynamic perturbations, e.g., force fields, may be used to manipulate movements in order to investigate these mechanisms. Here, we focus on how the presence of position- and velocity-dependent force fields affects the relation between speed and accuracy during hand reaching movements. Participants were instructed to perform reaching movements under visual control in two directions, corresponding to either low or high arm inertia. The subjects were required to maintain four different movement durations (very slow, slow, fast, very fast). The experimental protocol included three phases: (i) familiarization-the robot generated no force; (ii) force field-the robot generated a force; and (iii) after-effect-again, no force. Participants were randomly assigned to four groups, depending on the type of force that was applied during the "force field" phase....
2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015
It is commonly acknowledged that movement performance is determined by a trade-off between accura... more It is commonly acknowledged that movement performance is determined by a trade-off between accuracy requirements and energetic expenditure. However, their relative weights are subjective and depend on the perceived benefit (or cost) associated to successful movement completion. A deeper knowledge on how this trade-off affects motor behavior may suggest ways to manipulate it in pathologies, like Parkinson's disease, in which the mechanisms underlying the selection of motor response are believed to be defective. In this preliminary study, we associate a monetary incentive to successful completion of a full-body reaching task and look at the determinants of motor performance. Our preliminary results suggest that motor performance (measured as the absolute average acceleration of hand movements) increases with movement amplitude/target elevation. Overall, performance also increases with the amount of monetary incentive and with the average reward experienced in previous trials. In addition, subjects with a greater sensitivity to incentive exhibit a low sensitivity to the average reward. In contrast, subjects with a negative sensitivity to incentive exhibit a smaller sensitivity to the average reward. These results suggest that motor performance has a complex relation with its perceived benefits, and this relation is probably subject-dependent.
In the last decades, several studies showed that wearable sensors, used for assessing Parkinson&#... more In the last decades, several studies showed that wearable sensors, used for assessing Parkinson's disease (PD) motor symptoms and recording their fluctuations, could provide a quantitative and reliable tool for patient's motor performance monitoring. The aim of this study is to make a step forward the capability of quantitatively describing PD motor symptoms. The specific aims are: identify the most sensible place where to locate sensors to monitor PD bradykinesia and rigidity, and identify objective indexes able to discriminate PD OFF/ON motor status, and PD patients from healthy subjects (HSs). Fourteen PD patients (H&Y stage 1-2.5), and 13 age-matched HSs, were enrolled. Five magneto-inertial wearable sensors, placed on index finger, thumb, metacarpus, wrist, and arm, were used as motion tracking systems. Sensors were placed on the most affected arm of PD patients, and on dominant hand of HS. Three UPDRS part III tasks were evaluated: rigidity (task 22), finger tapping (t...
Ataxic syndromes include several rare, inherited and acquired conditions. One of the main issues ... more Ataxic syndromes include several rare, inherited and acquired conditions. One of the main issues is the absence of specific, and sensitive automatic evaluation tools and digital outcome measures to obtain a continuous monitoring of subjects' motor ability. Gait evaluation was performed by Kinect v2 in a cohort of young participant affected by ataxia syndrome. The dataset is composed of the spatio-temporal parameters calculated by the skeleton acquired by the Kinect sensor, by the diagnosis of each participant, and by the total score of the clinical scale SARA. These parameters have been previously validated and corrected as requested by the Bland-Altman test.
Adaptive training with full-body movements to reduce bradykinesia in persons with Parkinson’s dis... more Adaptive training with full-body movements to reduce bradykinesia in persons with Parkinson’s disease: a pilot study
Abstract-An important issue in sensorimotor adaptation is what drives adaptation, and whether dif... more Abstract-An important issue in sensorimotor adaptation is what drives adaptation, and whether different types of perturbations are mediated by different adaptation mechanisms. Here we assess whether any interference is observed among the joint adaptation to visual (i.e. kinematic) and force (i.e. dynamic) perturbations. Subjects adapted their reaching movements to rotations of the display. During adaptation, we perturbed their movements with a rotational force field, whose direction was either the same or the opposite of the visual perturbation (R+F and R-F groups). In the two groups, we compared the outcomes of both adaptation modalities. In addition, we analyzed the dynamics of the adaptation processes in terms of a number of linear dynamical models, based on different assumptions. We conclude that the two adaptation processes occur largely in parallel, with little interaction, and exhibit similar time constants, which suggests common underlying memory mechanisms. In addition, we ...
This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted P... more This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon. Natural interfaces and virtual environments for the acquisition of street crossing and path following skills in adults with Autism Spectrum Disorders: a feasibility study
This work involved human subjects or animals in its research. Approval of all ethical and experim... more This work involved human subjects or animals in its research. Approval of all ethical and experimental procedures and protocols was granted by the Local Ethical Committee under Protocol NET-2013-02356160 WP3, nr. 1619-2018. ABSTRACT Early onset ataxia represents a group of heterogeneous neurological conditions typically characterized by motor disability. Speech problems are one of the main core features of ataxic syndromes, where automatic and computational characterization of speech impairment might represent a source of biomarkers for early screening and stratification of patients. The main contribution of this paper consists in proposing a novel hierarchical machine learning model (HMLM) to improve detection and assessment of dysarthria from a structured speech disturbance test. Performances are tested on a new audio dataset containing 10 seconds recordings of standardized clinical PATA test for 55 subjects: 18 healthy subjects and 37 with ataxia. Results show that the proposed HMLM achieves performances with an accuracy of about 90% at the first level (healthy vs patients) selecting an optimal subset of conventional features. In cascade, at the second level, speech disturbance severity (Low vs High) is assessed using deep learning feature extraction technique based on a VGG pre-trained network with maximum accuracy of about 80%. Both levels are processed through the majority voting ensemble technique testing Support Vector Machine (SVM), k-Nearest Neighbors (kNN), Decision Tree (DT) and Naïve Bayes (NB). In our results, the use of HMLM considerably outperforms the results achieved with a single machine learning or deep learning modeling. These outcomes demonstrate that the investigation of the PATA speech test through HMLM can be considered very promising. We also observed that the use of conventional feature extraction techniques and machine learning modeling seems to be a good solution for the diagnosis of patients with ataxia, while the deep learning approach is more appropriate for stratification of severity of dysarthria.
This chapter reviews the state of the art of computational models for neuromotor recovery, with a... more This chapter reviews the state of the art of computational models for neuromotor recovery, with a focus on state-space models that describe the development of functional behaviors through exercise and on the relation between neuromotor recovery and motor learning. We first review models of the dynamics of sensorimotor adaptation and motor skill learning. We then elaborate on similarities and differences with neuromotor recovery. We finally discuss how these models can be used to achieve a better understanding of the role of robots to promote recovery and to develop personalized forms of treatment.
Moving platform are introduced in the field of the study of posturography since ’70 years. Commer... more Moving platform are introduced in the field of the study of posturography since ’70 years. Commercial platforms have some limits: a limited number of degrees of freedom; preconfigured protocols and usually they are expensive. In order to overcome these limits, we developed a robotized platform: DORIS. We aimed at realizing a versatile solution that can be applied both for research purpose but also for personalizing the training of equilibrium and gait. We reached these goals by means of a Stewart platform that was realized with linear actuators and a supporting plate. Each actuator is provided by a monoaxial ad hoc built load cell. Position and force control allow a multipurpose range of movement and a reactive interaction with the force applied by the subject. TCP/IP protocol guarantees the communication between the platform and other systems. Therefore, we integrated DORIS with motion analysis system, EMG system and virtual reality. The adopted solution offers the opportunity to m...
BackgroundGait Analysis of healthy people, imitating pathological conditions while walking, has i... more BackgroundGait Analysis of healthy people, imitating pathological conditions while walking, has increased our understanding of biomechanical factors. The influence of the pelvis as a biomechanical constraint during gait is not specifically studied. How could mimicking a pelvic attitude influence the dynamic mechanical interaction of the body segments? We proposed an investigation of the pelvic attitude role on the gait pattern of typically developed people when they mimicked pelvic anteversion and posteroversion.Materials and methodsSeventeen healthy volunteers were enrolled in this study (mean age 24.4 ± 5.5). They simulated a pelvic anteversion and posteroversion during walking, exaggerating these postures as much as possible. 3D gait analysis was conducted using an optoelectronic system with eight cameras (Vicon MX, Oxford, United Kingdom) and two force plates (AMTI, Or-6, Watertown, MA, United States). The kinematic, kinetic, and spatio-temporal parameters were compared between ...
Background and Objective: Absolute angle represents the inclination of a body segment relative to... more Background and Objective: Absolute angle represents the inclination of a body segment relative to a fixed reference in space. This work compares the absolute and relative angles for exploring biomechanical gait constraints. Methods: Gait patterns of different neuromotor conditions were analyzed using 3D gait analysis: normal gait (healthy, H), Cerebral Palsy (CP), Charcot Marie Tooth (CMT) and Duchenne Muscular Dystrophy (DMD), representing central and peripheral nervous system and muscular disorders, respectively. Forty-two children underwent gait analysis: 10 children affected by CP, 10 children by CMT, 10 children by DMD and 12 healthy children. The kinematic and kinetic parameters were collected to describe the biomechanical pattern of participants' lower limbs. The absolute angles of thigh, leg and foot were calculated using the trigonometric relationship of the tangent. For each absolute series, the mean, range, maximum, minimum and initial contact were calculated. Kinematic and kinetic gait data were studied, and the results were compared with the literature. Results: Statistical analysis of the absolute angles showed how, at the local level, the single segments (thigh, leg and foot) behave differently depending on the pathology. However, if the lower limb is studied globally (sum of the kinematics of the three segments: thigh, leg and foot), a biomechanical constraint emerges. Conclusion: Each segment compensates separately for the disease deficit so as to maintain a global biomechanical invariance. Using a model of inter-joint co-variation could improve the interpretation of the clinical gait pattern.
The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well ... more The aim of this consensus paper is to discuss the roles of the cerebellum in human gait, as well as its assessment and therapy. Cerebellar vermis is critical for postural control. The cerebellum ensures the mapping of sensory information into temporally relevant motor commands. Mental imagery of gait involves intrinsically connected fronto-parietal networks comprising the cerebellum. Muscular activities in cerebellar patients show impaired timing of discharges, affecting the patterning of the synergies subserving locomotion. Ataxia of stance/gait is amongst the first cerebellar deficits in cerebellar disorders such as degenerative ataxias and is a disabling symptom with a high risk of falls. Prolonged discharges and increased muscle coactivation may be related to compensatory mechanisms and enhanced body sway, respectively. Essential tremor is frequently associated with mild gait ataxia. There is growing evidence for an important role of the cerebellar cortex in the pathogenesis of essential tremor. In multiple sclerosis, balance and gait are affected due to cerebellar and spinal cord involvement, as a result of disseminated demyelination and neurodegeneration impairing proprioception. In orthostatic tremor, patients often show mild-to-moderate limb and gait ataxia. The tremor generator is likely located in the posterior fossa. Tandem gait is impaired in the early stages of cerebellar disorders and may be particularly useful in the evaluation of pre-ataxic stages of progressive ataxias. Impaired inter-joint coordination and enhanced variability of gait temporal and kinetic parameters can be grasped by wearable devices such as accelerometers. Kinect is a promising low cost technology to obtain reliable measurements and remote assessments of gait. Deep learning methods are being developed in order to help clinicians in the diagnosis and decision-making process. Locomotor adaptation is impaired in cerebellar patients. Coordinative training aims to improve the coordinative strategy and foot placements across strides, cerebellar patients benefiting from intense rehabilitation therapies. Robotic training is a promising approach to complement conventional rehabilitation and neuromodulation of the cerebellum. Wearable dynamic orthoses represent a potential aid to assist gait. The panel of experts agree that the understanding of the cerebellar contribution to gait control will lead to a better management of cerebellar ataxias in general and will likely contribute to use gait parameters as robust biomarkers of future clinical trials.
Background: Children with ataxia experience balance and movement coordination difficulties and ne... more Background: Children with ataxia experience balance and movement coordination difficulties and needs intensive physical intervention to maintain functional abilities and counteract the disorder. Exergaming represents a valuable strategy to provide engaging physical intervention to children with ataxia, sustaining their motivation to perform the intervention. This paper aims to describe the effect of a home-conducted exergame-based exercise training for upper body movements control of children with ataxia on their ataxic symptoms, walking ability, and hand dexterity. Methods: Eighteen children with ataxia were randomly divided into intervention and control groups. Participants in the intervention group were asked to follow a 12-week motor activity program at home using the Niurion® exergame. Blind assessments of participants’ ataxic symptoms, dominant and non-dominant hand dexterity, and walking ability were conducted. Results: On average, the participants performed the intervention ...
Background: It has been highlighted that obesity influences the gait reducing walking velocity, s... more Background: It has been highlighted that obesity influences the gait reducing walking velocity, stride length, ankle dorsal flexion at initial contact and ankle power generation. Meanwhile, step width, double support, hip flexion, knee extension during stance, hip moment and ankle power absorption was described increased. A tendency to the normalization of these parameters occur when subjects reduced their weight during growth. Objective: We studied the effect of fast weight loss due to Sleeve Gastrectomy on gait pattern of adolescent with severe obesity. The aim is to assess the functional benefit of the surgery. Setting: Pediatric hospital, public health, Italy. Methods: 11 patients before and after 1 year from surgery and 10 controls participated to the study. We studied the gait with an optoelectronic system and two force plates. We evaluated both kinetics and kinematics of walking. Then we looked at the differences between the pre-vs post-surgery and with the control group. Results: Step length and velocity were lower and step width was bigger in adolescent with obesity. Kinematic and kinetic parameters were altered. After surgery we observed the reduction of several gait alteration. Meanwhile, after 1 year alterations at the level of the foot, the knee and the pelvis persist. Conclusion: The sudden loss of weight highlighted the presence of long-term effects on the locomotor system. The results discourage intense walking activities before the weight loss and we suggest further studies for evaluating the necessity of a rehabilitative intervention.
Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest ... more Non-invasive focal mechanical vibrations (NIFMV) now represent a strategy of increasing interest to improve motor control in different neurological diseases. Nanotechnology allowed the creation of wearable devices transforming thermal variations into mechanical energy with focal vibrations. This kind of wearable stimulators (WS) has produced encouraging preliminary results when used in the treatment of movement disorders and ataxia in adults. In this open label pilot study we first evaluated the feasibility, safety and effectiveness of NIFMV by WS in a cohort of 10 patients with childhood ataxia, a phenomenological category including different conditions still lacking of effective symptomatic therapies. Through the assessment of both clinical rating scales and spatio-temporal gait parameters via standardized gait analysis, we observed that a 4 weeks long treatment with WS Equistasi® was safe and provided significantly different effects in stride features of patients with slow/non-pr...
The speed of voluntary movements is determined by the conflicting needs of maximizing accuracy an... more The speed of voluntary movements is determined by the conflicting needs of maximizing accuracy and minimizing mechanical effort. Dynamic perturbations, e.g., force fields, may be used to manipulate movements in order to investigate these mechanisms. Here, we focus on how the presence of position- and velocity-dependent force fields affects the relation between speed and accuracy during hand reaching movements. Participants were instructed to perform reaching movements under visual control in two directions, corresponding to either low or high arm inertia. The subjects were required to maintain four different movement durations (very slow, slow, fast, very fast). The experimental protocol included three phases: (i) familiarization-the robot generated no force; (ii) force field-the robot generated a force; and (iii) after-effect-again, no force. Participants were randomly assigned to four groups, depending on the type of force that was applied during the "force field" phase....
2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015
It is commonly acknowledged that movement performance is determined by a trade-off between accura... more It is commonly acknowledged that movement performance is determined by a trade-off between accuracy requirements and energetic expenditure. However, their relative weights are subjective and depend on the perceived benefit (or cost) associated to successful movement completion. A deeper knowledge on how this trade-off affects motor behavior may suggest ways to manipulate it in pathologies, like Parkinson's disease, in which the mechanisms underlying the selection of motor response are believed to be defective. In this preliminary study, we associate a monetary incentive to successful completion of a full-body reaching task and look at the determinants of motor performance. Our preliminary results suggest that motor performance (measured as the absolute average acceleration of hand movements) increases with movement amplitude/target elevation. Overall, performance also increases with the amount of monetary incentive and with the average reward experienced in previous trials. In addition, subjects with a greater sensitivity to incentive exhibit a low sensitivity to the average reward. In contrast, subjects with a negative sensitivity to incentive exhibit a smaller sensitivity to the average reward. These results suggest that motor performance has a complex relation with its perceived benefits, and this relation is probably subject-dependent.
In the last decades, several studies showed that wearable sensors, used for assessing Parkinson&#... more In the last decades, several studies showed that wearable sensors, used for assessing Parkinson's disease (PD) motor symptoms and recording their fluctuations, could provide a quantitative and reliable tool for patient's motor performance monitoring. The aim of this study is to make a step forward the capability of quantitatively describing PD motor symptoms. The specific aims are: identify the most sensible place where to locate sensors to monitor PD bradykinesia and rigidity, and identify objective indexes able to discriminate PD OFF/ON motor status, and PD patients from healthy subjects (HSs). Fourteen PD patients (H&Y stage 1-2.5), and 13 age-matched HSs, were enrolled. Five magneto-inertial wearable sensors, placed on index finger, thumb, metacarpus, wrist, and arm, were used as motion tracking systems. Sensors were placed on the most affected arm of PD patients, and on dominant hand of HS. Three UPDRS part III tasks were evaluated: rigidity (task 22), finger tapping (t...
Ataxic syndromes include several rare, inherited and acquired conditions. One of the main issues ... more Ataxic syndromes include several rare, inherited and acquired conditions. One of the main issues is the absence of specific, and sensitive automatic evaluation tools and digital outcome measures to obtain a continuous monitoring of subjects' motor ability. Gait evaluation was performed by Kinect v2 in a cohort of young participant affected by ataxia syndrome. The dataset is composed of the spatio-temporal parameters calculated by the skeleton acquired by the Kinect sensor, by the diagnosis of each participant, and by the total score of the clinical scale SARA. These parameters have been previously validated and corrected as requested by the Bland-Altman test.
Adaptive training with full-body movements to reduce bradykinesia in persons with Parkinson’s dis... more Adaptive training with full-body movements to reduce bradykinesia in persons with Parkinson’s disease: a pilot study
Abstract-An important issue in sensorimotor adaptation is what drives adaptation, and whether dif... more Abstract-An important issue in sensorimotor adaptation is what drives adaptation, and whether different types of perturbations are mediated by different adaptation mechanisms. Here we assess whether any interference is observed among the joint adaptation to visual (i.e. kinematic) and force (i.e. dynamic) perturbations. Subjects adapted their reaching movements to rotations of the display. During adaptation, we perturbed their movements with a rotational force field, whose direction was either the same or the opposite of the visual perturbation (R+F and R-F groups). In the two groups, we compared the outcomes of both adaptation modalities. In addition, we analyzed the dynamics of the adaptation processes in terms of a number of linear dynamical models, based on different assumptions. We conclude that the two adaptation processes occur largely in parallel, with little interaction, and exhibit similar time constants, which suggests common underlying memory mechanisms. In addition, we ...
This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted P... more This Provisional PDF corresponds to the article as it appeared upon acceptance. Fully formatted PDF and full text (HTML) versions will be made available soon. Natural interfaces and virtual environments for the acquisition of street crossing and path following skills in adults with Autism Spectrum Disorders: a feasibility study
This work involved human subjects or animals in its research. Approval of all ethical and experim... more This work involved human subjects or animals in its research. Approval of all ethical and experimental procedures and protocols was granted by the Local Ethical Committee under Protocol NET-2013-02356160 WP3, nr. 1619-2018. ABSTRACT Early onset ataxia represents a group of heterogeneous neurological conditions typically characterized by motor disability. Speech problems are one of the main core features of ataxic syndromes, where automatic and computational characterization of speech impairment might represent a source of biomarkers for early screening and stratification of patients. The main contribution of this paper consists in proposing a novel hierarchical machine learning model (HMLM) to improve detection and assessment of dysarthria from a structured speech disturbance test. Performances are tested on a new audio dataset containing 10 seconds recordings of standardized clinical PATA test for 55 subjects: 18 healthy subjects and 37 with ataxia. Results show that the proposed HMLM achieves performances with an accuracy of about 90% at the first level (healthy vs patients) selecting an optimal subset of conventional features. In cascade, at the second level, speech disturbance severity (Low vs High) is assessed using deep learning feature extraction technique based on a VGG pre-trained network with maximum accuracy of about 80%. Both levels are processed through the majority voting ensemble technique testing Support Vector Machine (SVM), k-Nearest Neighbors (kNN), Decision Tree (DT) and Naïve Bayes (NB). In our results, the use of HMLM considerably outperforms the results achieved with a single machine learning or deep learning modeling. These outcomes demonstrate that the investigation of the PATA speech test through HMLM can be considered very promising. We also observed that the use of conventional feature extraction techniques and machine learning modeling seems to be a good solution for the diagnosis of patients with ataxia, while the deep learning approach is more appropriate for stratification of severity of dysarthria.
This chapter reviews the state of the art of computational models for neuromotor recovery, with a... more This chapter reviews the state of the art of computational models for neuromotor recovery, with a focus on state-space models that describe the development of functional behaviors through exercise and on the relation between neuromotor recovery and motor learning. We first review models of the dynamics of sensorimotor adaptation and motor skill learning. We then elaborate on similarities and differences with neuromotor recovery. We finally discuss how these models can be used to achieve a better understanding of the role of robots to promote recovery and to develop personalized forms of treatment.
Moving platform are introduced in the field of the study of posturography since ’70 years. Commer... more Moving platform are introduced in the field of the study of posturography since ’70 years. Commercial platforms have some limits: a limited number of degrees of freedom; preconfigured protocols and usually they are expensive. In order to overcome these limits, we developed a robotized platform: DORIS. We aimed at realizing a versatile solution that can be applied both for research purpose but also for personalizing the training of equilibrium and gait. We reached these goals by means of a Stewart platform that was realized with linear actuators and a supporting plate. Each actuator is provided by a monoaxial ad hoc built load cell. Position and force control allow a multipurpose range of movement and a reactive interaction with the force applied by the subject. TCP/IP protocol guarantees the communication between the platform and other systems. Therefore, we integrated DORIS with motion analysis system, EMG system and virtual reality. The adopted solution offers the opportunity to m...
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