1,720,981 research outputs found
Observer-Agent Kinematic Similarity Facilitates Action Intention Decoding
No full textIt is well known that the kinematics of an action is modulated by the underlying motor intention. In turn, kinematics serves as a cue also during action observation, providing hints about the intention of the observed action. However, an open question is whether decoding others' intentions on the basis of their kinematics depends solely on how much the kinematics varies across different actions, or rather it is also influenced by its similarity with the observer motor repertoire. The execution of reach-to-grasp and place actions, differing for target size and context, was recorded in terms of upper-limb kinematics in 21 volunteers and in an actor. Volunteers had later to observe the sole reach-to-grasp phase of the actor's actions, and predict the underlying intention. The potential benefit of the kinematic actor-participant similarity for recognition accuracy was evaluated. In execution, both target size and context modulated specific kinematic parameters. More importantly, although participants performed above chance in intention recognition, the similarity of motor patterns positively correlated with recognition accuracy. Overall, these data indicate that kinematic similarity exerts a facilitative role in intention recognition, providing further support to the view of action intention recognition as a visuo-motor process grounded in motor resonance
Exergames in exercise-based cardiac rehabilitation for patients with heart failure: a systematic review
No full textAim: The aim of this study was to systematically review the current literature on the use of exergames as an exercise-based cardiac rehabilitation intervention for patients with heart failure. Methods: PubMed, SCOPUS and CINAHL Plus databases were searched from January 2007 to August 2023. Studies considered eligible for inclusion had to report one or more of the following outcomes: functional capacity (e.g. VO 2 max), quality of life, mortality, hospital admissions, physical activity level, and engagement/satisfaction of the intervention. Only studies reported in English were included. Two reviewers independently assessed studies for their eligibility. Results: Two studies (in four reports) were included. Included studies reported only data on functional capacity (6-min walking test) and on physical activity level (accelerometers). Due to the low number of included studies, no meta-analysis was performed, and results were discussed narratively. Conclusion: Exergames may potentially be a promising tool for exercise-based cardiac rehabilitation in patients with heart failure; however, the low number of included studies was insufficient to drawn proper conclusions. Benefits of exergames compared with traditional interventions could be the possibility of it being delivered at home, reducing some of the barriers that patients with heart failure must face. Further studies are required to assess the efficacy of exergame interventions in patients with heart failure, and to define proper guidelines to deliver exergame interventions in this population.This systematic review was registered on PROSPERO (CRD42023446948)
Differences in Weight-Acceptance Phase during Landing in Block Jumps: A Pilot Study on Female Volleyball Players
No full textThe anterior cruciate ligament (ACL) plays a crucial role in constraining tibiofemoral articulation and preserving the knee joint from harmful aberrations of movement. However, certain high-risk movements, such as landing, can induce ACL injuries. Volleyball practice intrinsically requires performing jumps during attacking and defending phases, with a higher rate of ACL injury occurring during blocking tasks. The execution of these tasks is more subject to variability due to the necessity of adequately counteracting opponents. The type of landing after blocking, as well as gender, has been related to the potential risk of injury. We analyzed two different blocking techniques frequently occurring during volleyball matches: The block jump with double-leg landing and the block jump with single-leg landing (dominant and non-dominant). Synchronized kinematic and kinetic data from female volleyball players were collected using a set of wearable inertial measurement units (IMUs), force platforms, and wireless surface electromyography (EMG). Kinematic and kinetic data were evaluated during the weight-Acceptance phase in each task to determine changes in landing approaches. Block jumping with single-leg landing resulted in changes in the kinematics at the hip, knee, and ankle levels, and higher values of muscular activation during the first instants of weight acceptance, particularly in the biceps femoris and gastrocnemius. Understanding the overall biomechanics associated with different sports tasks allows for a better understanding of personal risk and the definition of proper training programs aimed at injury prevention
Case Study of Surgeon's Kinematics Performing Arthroscopy in Real and Simulation Scenarios: A Multisensor Approach
Full text linkTelerehabilitation in response to constrained physical distance: an opportunity to rethink neurorehabilitative routines
No full textEnsuring proper dosage of treatment and repetition over time is a major challenge in neurorehabilitation. However, a requirement of physical distancing to date compromises their achievement. While mostly associated to COVID-19, physical distancing is not only required in a pandemic scenario, but also advised for several clinical conditions (e.g. immunocompromised individuals) or forced for specific social contexts (e.g. people living in remote areas worldwide). All these contexts advocate for the implementation of alternative healthcare models. The objective of this perspective is to highlight the benefits of remote administration of rehabilitative treatment, namely telerehabilitation, in counteracting physical distancing barriers in neurorehabilitation. Sustaining boosters of treatment outcome, such as compliance, sustainability, as well as motivation, telerehabilitation may adapt to multiple neurological conditions, with the further advantage of a high potential for individualization to patient's or pathology's specificities. The effectiveness of telerehabilitation can be potentiated by several technologies available to date: virtual reality can recreate realistic environments in which patients may bodily operate, wearable sensors allow to quantitatively monitor the patient's performance, and signal processing may contribute to the prediction of long-term dynamics of patient recovery. Telerehabilitation might spark its advantages far beyond the mere limitation of physical distancing effects, mitigating criticalities of daily neurorehabilitative practice, and thus paving the way to the envision of mixed models of care, where hospital-based procedures are complementarily integrated with telerehabilitative ones
Validation of inter-subject training for hidden markov models applied to gait phase detection in children with Cerebral Palsy
Full text linkGait-phase recognition is a necessary functionality to drive robotic rehabilitation devices for lower limbs. Hidden Markov Models (HMMs) represent a viable solution, but they need subject-specific training, making data processing very time-consuming. Here, we validated an inter-subject procedure to avoid the intra-subject one in two, four and six gait-phase models in pediatric subjects. The inter-subject procedure consists in the identification of a standardized parameter set to adapt the model to measurements. We tested the inter-subject procedure both on scalar and distributed classifiers. Ten healthy children and ten hemiplegic children, each equipped with two Inertial Measurement Units placed on shank and foot, were recruited. The sagittal component of angular velocity was recorded by gyroscopes while subjects performed four walking trials on a treadmill. The goodness of classifiers was evaluated with the Receiver Operating Characteristic. The results provided a goodness from good to optimum for all examined classifiers (0 < G < 0.6), with the best performance for the distributed classifier in two-phase recognition (G = 0.02). Differences were found among gait partitioning models, while no differences were found between training procedures with the exception of the shank classifier. Our results raise the possibility of avoiding subject-specific training in HMM for gait-phase recognition and its implementation to control exoskeletons for the pediatric population
Choosing a similarity index to quantify gait data variability
Full text linkRepeatability and reproducibility of joint kinematics can be assessed through Similarity Indices (SI) quantifying their pattern variability. These include: Coefficient of Multiple Correlation (CMC) [1]; Mean Absolute Variability (MAV) [2]; and Linear Fit Method (LFM) [3], which accounts for scaling (a1), offset (a0) and truthfulness of the linear model between the curves (R2). Among gait cycles, the intra-subject variability for a given joint is due to physiological fluctuations of the range of motion (ROM) and time shift. SIs might be differently affected for each joint, due to their different ROMs, and by marker positioning, leading to offsets among gait curves. This paper aims to investigate the effects that each of these sources of curve variability has on the SIs, in order to provide indications on which is the most suitable for the assessment of gait similarity
The Proactive Synergy Between Action Observation and Execution in the Acquisition of New Motor Skills
No full textMotor learning can be defined as a process that leads to relatively permanent changes in motor behavior through repeated interactions with the environment. Different strategies can be adopted to achieve motor learning: movements can be overtly practiced leading to an amelioration of motor performance; alternatively, covert strategies (e.g., action observation) can promote neuroplastic changes in the motor system even in the absence of real movement execution. However, whether a training regularly alternating action observation and execution (i.e., Action Observation Training, AOT) may surpass the pure motor practice (MP) and observational learning (OL) remains to be established. To address this issue, we enrolled 54 subjects requiring them to learn tying nautical knots via one out of three types of training (AOT, MP, OL) with the scope to investigate which element mostly contributes to motor learning. We evaluated the overall improvement of each group, along with the predictive role that neuropsychological indexes exert on each treatment outcome. The AOT group exhibited the highest performance improvement (42%), indicating that the regular alternation between observation and execution biases participants toward a better performance. The reiteration of this sequence provides an incremental, adjunct value that super-adds onto the efficacy of motor practice or observational learning in isolation (42% > 25% + 10%, i.e., OL + MP). These findings extend the use of the AOT from clinical and rehabilitative contexts to daily routines requiring the learning and perfectioning of new motor skills such as sports training, music, and occupational activities requiring fine motor control
Performance evaluation of 3D reaching tasks using a low-cost haptic device and virtual reality
No full textIn this paper we propose a new protocol based on Virtual Reality and a low-cost haptic device for evaluating motion performance during perturbed 3D reaching tasks. The protocol presented herein was designed to assess how different force amplitudes and different reaching directions influence motor performance of healthy subjects. We developed a novel gaming scenario using Unity 3D and the Novint Falcon, a low-cost haptic joystick. The protocol consisted of six 3D point-to-point reaching tasks, which were performed by means of the Falcon while six different force fields were applied. Five subjects were enrolled in the study. During each task, subjects were asked to reach 80 targets. The trajectories of the end-effector, during each task, were recorded to calculate the following kinematic indices: duration of movement, length ratio, lateral deviation, aiming angle, speed metric and normalized jerk. The coefficient of variation was calculated to study the intra-subject variability to establish which indices better assessed the accuracy and the smoothness of the trajectories. Subsequently, two-way repeated measurement ANOVA tests were performed for all indices in order to ascertain effects of the 6 levels of force and the 8 directions of the reaching task. Length ratio and speed metric have proven the highest intra-subject repeatability as accuracy and smoothness indices, respectively. Statistical analysis demonstrated that all the accuracy indices are not sensitive to amplitude variation of the applied force field, nor to different target directions. Conversely, the smoothness indices showed statistical differences in both forces and directions. In particular, the speed metric is sensitive to the applied force, and the normalized jerk depends on the target directions
Inter-laboratory and inter-operator reproducibility in gait analysis measurements in pediatric subjects
Full text linkThe intra-subject, the inter-operator, and the inter-laboratory variabilities are the main sources of uncertainties in gait analysis, and their effects have been partially described in the literature for adult populations. This study aimed to extend the repeatability and reproducibility analysis to a pediatric population, accounting for the effects induced by the intra-subject variations, the measurement setup, the marker set configuration, and the involved operators in placing markers and EMG electrodes. We evaluated kinematic, kinetic and EMG outputs collected from gait analyses performed on two healthy children in two laboratories, by two operators, and with two marker placement protocols. The two involved centers previously defined a common acquisition procedure based on their routine pipelines. The similarity of kinematic, kinetic, and EMG curves were evaluated by means of the coefficients of the Linear Fit Method, and the Mean Absolute Variability with and without the offset among curves. The inter-operator variability was found to be the main contribution to the overall reproducibility of kinematic and kinetic gait data. On the contrary, the main contribution to the variability of the EMG signals was the intra-subject repeatability that is due to the physiological stride to stride muscle activation variability
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