An Overview of Wearable Haptic Technologies and Their Performance in Virtual Object Exploration.

We often interact with our environment through manual handling of objects and exploration of their properties. Object properties (OP), such as texture, stiffness, size, shape, temperature, weight, and orientation provide necessary information to successfully perform interactions. The human haptic perception system plays a key role in this. As virtual reality (VR) has been a growing field of interest with many applications, adding haptic feedback to virtual experiences is another step towards more realistic virtual interactions. However, integrating haptics in a realistic manner, requires complex technological solutions and actual user-testing in virtual environments (VEs) for verification. This review provides a comprehensive overview of recent wearable haptic devices (HDs) categorized by the OP exploration for which they have been verified in a VE. We found 13 studies which specifically addressed user-testing of wearable HDs in healthy subjects. We map and discuss the different technological solutions for different OP exploration which are useful for the design of future haptic object interactions in VR, and provide future recommendations

(HIIT-The Track) High-Intensity Interval Training for People with Parkinson's Disease: Individual Response Patterns of (Non-)Motor Symptoms and Blood-Based Biomarkers-A Crossover Single-Case Experimental Design.

INTRODUCTION Physical exercise is receiving increasing interest as an augmentative non-pharmacological intervention in Parkinson's disease (PD). This pilot study primarily aimed to quantify individual response patterns of motor symptoms to alternating exercise modalities, along with non-motor functioning and blood biomarkers of neuroplasticity and neurodegeneration. MATERIALS & METHODS People with PD performed high-intensity interval training (HIIT) and continuous aerobic exercise (CAE) using a crossover single-case experimental design. A repeated assessment of outcome measures was conducted. The trajectories of outcome measures were visualized in time series plots and interpreted relative to the minimal clinically important difference (MCID) and smallest detectable change (SDC) or as a change in the positive or negative direction using trend lines. RESULTS Data of three participants were analyzed and engaging in physical exercise seemed beneficial for reducing motor symptoms. Participant 1 demonstrated improvement in motor function, independent of exercise modality; while for participant 2, such a clinically relevant (positive) change in motor function was only observed in response to CAE. Participant 3 showed improved motor function after HIIT, but no comparison could be made with CAE because of drop-out. Heterogeneous responses on secondary outcome measures were found, not only between exercise modalities but also among participants. CONCLUSION Though this study underpins the positive impact of physical exercise in the management of PD, large variability in individual response patterns to the interventions among participants makes it difficult to identify clear exercise-induced adaptations in functioning and blood biomarkers. Further research is needed to overcome methodological challenges in measuring individual response patterns

Impact of early applied upper limb stimulation: The EXPLICIT-stroke programme design

Main claims of the literature are that functional recovery of the paretic upper limb is mainly defined within the first month post stroke and that rehabilitation services should preferably be applied intensively and in a task-oriented way within this particular time window. EXplaining PLastICITy after stroke (acronym EXPLICIT-stroke) aims to explore the underlying mechanisms of post stroke upper limb recovery. Two randomized single blinded trials form the core of the programme, investigating the effects of early modified Constraint-Induced Movement Therapy (modified CIMT) and EMG-triggered Neuro-Muscular Stimulation (EMG-NMS) in patients with respectively a favourable or poor probability for recovery of dexterity.BioMechanical EngineeringMechanical, Maritime and Materials Engineerin

Trunk inflexibility and postural stability in Parkinson\u27s disease

Postural stability and rigidity are two of the major motor symptoms of Parkinson\u27s disease (PD). Falls in PD tend to happen mainly during tasks involving turning and bending motions of the upper body. Although correlations between clinical measures of postural stability and axial rigidity have been reported, the nature in which axial rigidity affects postural control mechanisms in PD remains undetermined. The purpose of this dissertation was (1) to investigate changes in control of the upper body due to aging and PD and (2) to study the impact of these changes on the interaction of posture and manual control. In two experimental series, patients with PD as well as healthy younger and healthy older controls were tested under manipulations of upper body motion and proximity to stability boundaries while standing. Overall, PD patients were able to adapt their postural strategies to changing task demands and adequately performed the required tasks without falling. Across both experiments, a lack of adaptability in pelvis-trunk coordination as well as reduced segmental ranges of motion were observed in patients with PD. Patterns of center of pressure and trunk center of motion suggested that aging alone mainly affects control of reactive forces at the foot-support surface interface, while PD patients show additional impairments in controlling the upper body. PD patients showed both increased and decreased variability in movement patterns compared to controls, undermining the traditional notion that increased variability characterizes movement pathology and equates with postural instability. The results stress the importance of incorporating analysis of three dimensional upper body motions into the study of balance impairments. The findings overall suggest that in PD changes in adaptive control of upper body motion are related to changes in postural control mechanisms

An Overview of Wearable Haptic Technologies and Their Performance in Virtual Object Exploration

We often interact with our environment through manual handling of objects and exploration of their properties. Object properties (OP), such as texture, stiffness, size, shape, temperature, weight, and orientation provide necessary information to successfully perform interactions. The human haptic perception system plays a key role in this. As virtual reality (VR) has been a growing field of interest with many applications, adding haptic feedback to virtual experiences is another step towards more realistic virtual interactions. However, integrating haptics in a realistic manner, requires complex technological solutions and actual user-testing in virtual environments (VEs) for verification. This review provides a comprehensive overview of recent wearable haptic devices (HDs) categorized by the OP exploration for which they have been verified in a VE. We found 13 studies which specifically addressed user-testing of wearable HDs in healthy subjects. We map and discuss the different technological solutions for different OP exploration which are useful for the design of future haptic object interactions in VR, and provide future recommendations

Short-Term Effects of Cerebellar tDCS on Standing Balance Performance in Patients with Chronic Stroke and Healthy Age-Matched Elderly

Transcranial direct current stimulation (tDCS) may serve as an adjunct approach in stroke rehabilitation. The cerebellum could be a target during standing balance training due to its role in motor adaptation. We tested whether cerebellar tDCS can lead to short-term effects on standing balance performance in patients with chronic stroke. Fifteen patients with a chronic stroke were stimulated with anodal stimulation on the contra-lesional cerebellar hemisphere, ipsi-lesional cerebellar hemisphere, or sham stimulation, for 20 min with 1.5 mA in three sessions in randomized order. Ten healthy controls participated in two sessions with cerebellar stimulation ipsi-lateral to their dominant leg or sham stimulation. During stimulation, subjects performed a medio-lateral postural tracking task on a force platform. Standing balance performance was measured directly before and after each training session in several standing positions. Outcomes were center of pressure (CoP) amplitude and its standard deviation, and velocity and its standard deviation and range, subsequently combined into a CoP composite score (comp-score) as a qualitative outcome parameter. In the patient group, a decrease in comp-score in the tandem position was found after contra-lesional tDCS: β = - 0.25, CI = - 0.48 to - 0.03, p = 0.03. No significant differences in demographics and clinical characteristics were found between patients who responded (N = 10) and patients who did not respond (N = 5) to the stimulation. Contra-lesional cerebellar tDCS shows promise for improving standing balance performance. Exploration of optimal timing, dose, and the relation between qualitative parameters and clinical improvements are needed to establish whether tDCS can augment standing balance performance after stroke

Symptom dimensions of anxiety in Parkinson's disease: Replication study in a neuropsychiatric patient population

Introduction: Anxiety disorders occur in approximately one third of people with Parkinson's disease (PD), and have a major impact on patient and caregiver wellbeing. In order to better understand and diagnose anxiety in PD patients, we investigated the generalizability of the results of a previous factor analysis on anxiety symptoms to a sample of PD patients with neuropsychiatric symptoms. Methods: In this cross-sectional study, anxiety symptoms were measured with the Beck Anxiety Inventory (BAI) in 123 PD patients who were referred for neuropsychiatric diagnostics and treatment. Subscales of anxiety were analyzed through principal component analysis of BAI items. The associations between BAI subscales and symptoms of motor and cognitive function and depression were assessed through regression analyses. Results: Similar to the previous factor analysis, we found one psychological (affective) and four somatic subscales of anxiety in the BAI. The affective subscale was the principal component explaining 35.9% of the variance. The scores on the total BAI and the affective subscale were significantly associated with depressive symptoms. In a post-hoc analysis, the affective subscale had equal power as compared to the total BAI in predicting whether or not participants were diagnosed with an anxiety disorder after psychiatric evaluation. Conclusion: In this study, we replicated our previous findings of one affective and multiple somatic subscales of the BAI. The 7-item affective subscale of the BAI shows potential as a screening tool for non-episodic anxiety in PD. However, in clinical practice, we recommend evaluating anxiety symptoms in the context of other PD symptoms, including motor, autonomic, and other (neuro)psychiatric symptoms

Prospectively Classifying Community Walkers After Stroke: Who Are They?

Objective: To classify patients with stroke into subgroups based on their characteristics at the moment of discharge from inpatient rehabilitation in order to predict community ambulation outcome 6 months later. Design: Prospective cohort study with a baseline measurement at discharge from inpatient care and final outcome determined after 6 months. Setting: Community. Participants: A cohort of patients (N=243) with stroke, referred for outpatient physical therapy, after completing inpatient rehabilitation in The Netherlands. Interventions: Not applicable. Main Outcome Measures: A classification model was developed using Classification And Regression Tree (CART) analysis. Final outcome was determined using the community ambulation questionnaire. Potential baseline predictors included patient demographics, stroke characteristics, use of assistive devices, comfortable gait speed, balance, strength, motivation, falls efficacy, anxiety, and depression. Results: The CART model accurately predicted independent community ambulation in 181 of 193 patients with stroke, based on a comfortable gait speed at discharge of 0.5 meters per second or faster. In contrast, 27 of 50 patients with gait speeds below 0.5 meters per second were correctly predicted to become noncommunity walkers. Conclusions: We show that comfortable gait speed is a key factor in the prognosis of community ambulation outcome. The CART model may support clinicians in organizing community services at the moment of discharge from inpatient care

Brain activation is related to smoothness of upper limb movements after stroke

It is unclear whether additionally recruited sensorimotor areas in the ipsilesional and contralesional hemisphere and the cerebellum can compensate for lost neuronal functions after stroke. The objective of this study was to investigate how increased recruitment of secondary sensorimotor areas is associated with quality of motor control after stroke. In seventeen patients (three females, fourteen males; age: 59.9 ± 12.6 years), cortical activation levels were determined with functional magnetic resonance imaging (fMRI) in 12 regions of interest during a finger flexion–extension task in weeks 6 and 29 after stroke. At the same time points and by using 3D kinematics, the quality of motor control was assessed by smoothness of the grasp aperture during a reach-to-grasp task, quantified by normalized jerk. Ipsilesional premotor cortex, insula and cerebellum, as well as the contralesional supplementary motor area, insula and cerebellum, correlated significantly and positively with the normalized jerk of grasp aperture at week 6 after stroke. A positive trend towards this correlation was observed in week 29. This study suggests that recruitment of secondary motor areas at 6 weeks after stroke is highly associated with increased jerk during reaching and grasping. As jerk represents the change in acceleration, the recruitment of additional sensorimotor areas seems to reflect a type of control in which deviations from an optimal movement pattern are continuously corrected. This relationship suggests that additional recruitment of sensorimotor areas after stroke may not correspond to restitution of motor function, but more likely to adaptive motor learning strategies to compensate for motor impairments