Motor Tasks Research Articles

Using a tablet to understand the spatial and temporal characteristics of complex upper limb movements in chronic stroke

Robotic devices are commonly used to quantify sensorimotor function of the upper limb after stroke; however, the availability and cost of such devices make it difficult to facilitate implementation in clinical environments. Tablets (e.g. iPad) can be used as devices to facilitate rehabilitation but are rarely used as assessment tools for the upper limb. The current study aimed to implement a tablet-based Maze Navigation Task to examine complex upper-limb movement in individuals with chronic stroke. We define complex upper-limb movement as reaching movements that require multi-joint coordination in a dynamic environment. We predicted that individuals with stroke would have more significant spatial errors, longer movement times, and slower speeds compared to controls with increasing task complexity. Twenty individuals with chronic stroke who had a variety of arm and hand function (Upper extremity Fugl-Myer 52.8 ± 18.3) and twenty controls navigated eight pseudorandomized mazes on an iPad using a digitizing stylus. The task was designed to elicit reaching movements engaging both the shoulder and elbow joints. Each maze became increasingly complex by increasing the number of 90° turns. We instructed participants to navigate each maze as quickly and accurately as possible while avoiding the maze’s boundaries. Sensorimotor behavior was quantified using the following metrics: Error Time (time spent hitting or outside boundaries), Peak Speed, Average Speed, and Movement Time, Number of Speed Peaks. We found that individuals with stroke had significantly greater Error Time for all maze levels (all, p < 0.01), while both speed metrics, Movement Time and Number of Speed Peaks were significantly lower for several levels (all, p < 0.05). As maze complexity increased, the performance of individuals with stroke worsened only for Error Time while control performance remained consistent (p < 0.001). Our results indicate that a complex movement task on a tablet can capture temporal and spatial impairments in individuals with stroke, as well as how task complexity impacts movement quality. This work demonstrates that a tablet is a suitable tool for the assessment of complex movement after stroke and can serve to inform rehabilitation after stroke.

Joint kinetic demand for performance in high jump

ABSTRACT High jump is a power-demanding motor task. Jumpers extend the take-off leg joints with maximum effort, but kinetic requirements (i.e. torque/power) for each joint are unclear. Here we show the inter-joint differences in the kinetic exertion related to the flight height in high jump trials by 16 male high jumpers (personal best record: 1.90–2.35 m). For the knee joint, both maximum net power and maximum norm of torque were significantly and positively correlated with flight height, with a stronger correlation for maximum net power (r = 0.70) than for maximum norm of torque (r = 0.52). For the hip joint, maximum norm of torque was significantly correlated with flight height (r = 0.62), but maximum net power (r = 0.36) was not. Both torque and power exhibited the proximal-to-distal sequence (from hip to ankle). The norm of ground reaction force peaked almost simultaneously with the hip torque while external net power peaked with knee power. We suggest that the required musculoskeletal function of each joint differs even in the same task. We suggest that it may be effective to adapt the different training programme between joints to improve performance. Jumpers should prioritise torque exertion for the hip and power exertion for the knee.

The Effect of Cognitive and Motor Dual Tasks on the Synergy of Lower Limb Muscles During Walking.

Walking is one of the most complex human movements that can be affected by various sources of attention. Dual tasks reduce attention, increase information processing, and may alter control mechanisms such as synergy. However, the effect of dual tasks on muscle synergy remains unknown. Therefore, this study aimed to investigate the effect of cognitive and motor dual tasks on the synergy of lower limb muscles during walking. Twenty-four participants were selected voluntarily. The activity of the eight lower limb muscles was recorded under three different conditions: normal walking without a dual task, walking with a cognitive dual task, and walking with a motor dual task. A nonnegative matrix factorization algorithm and the variance accounted for were used to extract muscle synergy. The repeated-measures analysis of variance test and Pearson's correlation coefficient were performed to analyze the data. In this study, five muscle synergies were extracted from electromyography data using the variance accounted for method under three different conditions. The pattern of muscle synergies showed moderate to strong correlations. Peaks of synergies changed, and a time shift in synergy peaks during walking was observed. However, the number of extracted synergies did not change. The number of recruited muscle synergies remained consistent across different conditions. Dual tasks affect the higher levels of the motor control system, causing interference in information processing that leads to a shift in the tendency of synergy and weight coefficients of the muscles, ultimately resulting in a change in walking mechanics.

Relationship between initial motor variability and learning and adaptive ability. A systematic review.

Motor variability is an intrinsic feature of human beings that has been associated with the ability for learning and adaptation to specific tasks. The purpose of this review is to examine whether there is a possible direct relationship between individuals' initial variability, in both amount and structure variability, in their ability for learning and adaptation in motor tasks. Eighteen articles examined the relationship between initial motor variability and the ability for learning and adaptation. Twelve found a direct relationship. In reward learning task greater amount variability was associated with greater improvement learning, however, this association was not observed with structure variability. While in error learning task associations were reported with both greater amount variability and more complexity structure. Nevertheless, bias in initial performance related to the amount of variability was found, so the structure of initial variability seems to be a better indicator of improvement in this type of task. Further research is needed for further research to better understand the potential relationship between initial motor variability and the ability for learning and adaptation in motor tasks.

Comparing conventional and action video game training in visual perceptual learning.

Action video game (AVG) playing has been found to transfer to a variety of laboratory tasks in visual cognition. More recently, it has even been found to transfer to low-level visual "psychophysics tasks. This is unexpected since such low-level tasks have traditionally been found to be largely "immune" to transfer from another task, or even from the same task but a different stimulus attribute, e.g., motion direction. In this study, we set out to directly quantify transfer efficiency from AVG training to motion discrimination. Participants (n = 65) trained for 20h on either a first-person active shooting video game, or a motion direction discrimination task with random dots. They were tested before, midway, and after training with the same motion task and an orientation discrimination task that had been shown to receive transfer from AVG training, but not from motion training. A subsequent control group (n = 18) was recruited to rule out any test-retest effect, by taking the same tests with the same time intervals, but without training. We found that improvement in motion discrimination performance was comparable between the AVG training and control groups, and less than the motion discrimination training group. We could not replicate the AVG transfer to orientation discrimination, but this was likely due to the fact that our participants were practically at chance for this task at all test points. Our study found no evidence, in either accuracy or reaction time, that AVG training transferred to motion discrimination. Overall, our results suggest that AVG training transferred little to lower-level visual skills, refining understanding of the mechanisms by which AVGs may affect vision. Protocol registration The accepted stage 1 protocol for this study can be found on the Open Science Framework at https://osf.io/zdv9c/?view_only=5b3b0c161dad448d9d1d8b14ce91ab11 . The stage 1 protocol for this Registered Report was accepted in principle on 01/12/22. The protocol, as accepted by the journal, can be found at: https://doi.org/10.17605/OSF.IO/ZDV9C.

A kinematic dataset of locomotion with gait and sit-to-stand movements of young adults

Kinematic data is a valuable source of movement information that provides insights into the health status, mental state, and motor skills of individuals. Additionally, kinematic data can serve as biometric data, enabling the identification of personal characteristics such as height, weight, and sex. In CeTI-Locomotion, four types of walking tasks and the 5 times sit-to-stand test (5RSTST) were recorded from 50 young adults wearing motion capture (mocap) suits equipped with Inertia-Measurement-Units (IMU). Our dataset is unique in that it allows the study of both intra- and inter-participant variability with high quality kinematic motion data for different motion tasks. Along with the raw kinematic data, we provide the source code for phase segmentation and the processed data, which has been segmented into a total of 4672 individual motion repetitions. To validate the data, we conducted visual inspection as well as machine-learning based identity and action recognition tests, achieving 97% and 84% accuracy, respectively. The data can serve as a normative reference of gait and sit-to-stand movements in healthy young adults and as training data for biometric recognition.

Anti-saccade can be used as a screening tool for early cognitive impairment: a correlation study based on anti-saccade parameters and cognitive function.

Eye movement tasks, especially anti-saccade tasks, have been used to assess cognitive function in patients with neuropsychiatric disorders. Although it has been shown that individuals with cognitive impairment perform worse on anti-saccades tasks, there is a lack of systematic evaluation of the sensitivity of parameters of anti-saccades to assess different subtypes of cognitive impairment. A total of 158 participants were enrolled in this study, consisting of 66 men and 92 women, with an average age of 50.2 ± 10 years. The comparison of pro-saccade reaction time, anti-saccade reaction time, and error rates in the saccade task between individuals with cognitive impairments and a normal group was conducted. Furthermore, we systematically analyzed the correlations between the performance in neurological function tests (Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), Stroop) and these anti-saccade parameters. Especially, the correlation between these parameters and cognitive function in different domains of the MoCA task were also evaluated. The pro-saccade reaction time, anti-saccade reaction time and error rate were negatively correlated with the MMSE and MoCA scores (P < 0.001), and positively correlated with the time used in Stroop tasks. Among them, the error rate had the strongest correlation with the performance of MMSE, MoCA and Stroop tasks (MoCA: P < 0.0001, r2 = -0.608; MMSE: P < 0.0001, r2 = -0.344; Stroop: P < 0.0001, r2 = 0.455). Among the seven cognitive domains examined by the MoCA task, error rates had relatively high correlations with visuospatial/executive (P < 0.0001, r2 = -0.4660) and delayed recall (P < 0.0001, r2 = -0.4228) compared to naming, language (P = 0.0004, r2 = -0.0788), attention (P = 0.0004, r2 = -0.0780), abstraction (P < 0.0001, r2 = -0.1515), orientation (P < 0.0001, r2 = -0.1075). Moreover, pro-saccade reaction time, anti-saccade reaction time and error rate of people with high MoCA scores were significantly higher than those of people with low MoCA scores, which can be used to identify people with mild cognitive impairment. Our study's results provide valuable clinical evidence supporting the effectiveness of anti-saccades in assessing cognitive impairment, which is beneficial for screening and timely clinical intervention in individuals with specific cognitive impairment.

A multi-objective optimal control approach to motor strategy changes in older people with mild cognitive impairment during obstacle crossing.

Mild cognitive impairment (MCI) may lead to difficulty maintaining postural stability and balance during locomotion. This heightened susceptibility to falls is particularly evident during tasks such as obstacle negotiation, which demands efficient motor planning and reallocation of attentional resources. This study proposed a multi-objective optimal control (MOOC) technique to assess the changes in motor control strategies during obstacle negotiation in older people affected by amnestic MCI. Motion data from 12 older adults with MCI and 12 controls when crossing obstacles were measured using a motion capture system, and used to obtain the control strategy of obstacle-crossing as the best compromise between the conflicting objectives of the MOOC problem, i.e., minimising mechanical energy expenditure and maximising foot-obstacle clearance. Comparisons of the weighting sets between groups and obstacle heights were performed using a two-way analysis of variance with a significance level of 0.05. Compared to the controls, the MCI group showed significantly lower best-compromise weightings for mechanical energy expenditure but greater best-compromise weightings for both heel- and toe-obstacle clearances. This altered strategy involved a trade-off, prioritising maximising foot-obstacle clearance at the expense of increased mechanical energy expenditure. The MCI group could successfully navigate obstacles with a normal foot-obstacle clearance but at the cost of higher mechanical energy expenditure. MCI alters the best-compromise strategy between minimising mechanical energy expenditure and maximising foot-obstacle clearances for obstacle-crossing in older people. These findings provide valuable insights into how MCI impacts motor tasks and offer potential strategies for mitigating fall risks in individuals with MCI. Moreover, this approach could serve as an assessment tool for early diagnosis and a more precise evaluation of disease progression. It may also have applications for individuals with impairments in other cognitive domains.

Attentional focus modulates physiological response to arousal in a competitive putting task

Attentional focus during the execution of perceptual motor tasks has been shown to affect performance outcomes. The purpose of this study is to assess the physiological changes prompted by attentional focus in various levels of stress. Thirty-six healthy young males and females were randomized into groups and directed on attentional focus in a staged putting competition scenario intended to elicit competitive anxiety. External focus groups experienced less internal workload at all arousal levels and preserved heart rate variability measures when audiovisual distraction was introduced.

Characterizing practice-dependent motor learning after a stroke.

After stroke, patients must learn to use residual motor function correctly. Consistently, motor learning is crucial in stroke motor recovery. We assessed motor performance, practice-dependent on-line motor learning, and factors potentially affecting them in stroke patients. This is a cross-sectional observational study. Twenty-six patients with first brain stroke leading to upper limb motor deficit in the subacute or chronic timeframe were enrolled. They performed a Finger Tapping Task (FTT) with both the affected and unaffected limbs. We assessed how patients learn to perform motor tasks despite the motor deficit and the differences in performance between the unaffected and affected limbs. Furthermore, by randomizing the order, we evaluated the possible inter-limb transfer of motor learning (i.e. transfer of a motor skill learned in one limb to the opposite one). Moreover, sleep, attention, anxiety, and depression were assessed through specific tests and questionnaires. Improved FTT accuracy and completed sequences for the affected limb were observed, even if lower than for the unaffected one. Furthermore, when patients initially performed the FTT with the unaffected limb, they showed higher accuracy in subsequent task completion with the affected limb than subjects who started with the affected limb. Only anxiety and attentional abilities showed significant correlations with motor performance. This work provides relevant insights into motor learning in stroke. Practice-dependent on-line motor learning is preserved in stroke survivors, and an inter-limb transfer effect can be observed. Attentional abilities and anxiety can affect learning after stroke, even if the effect of other factors cannot be excluded.

Changes of upper-limb kinematics during practice of a redundant motor task in patients with Parkinson’s disease

The ability to learn novel motor skills is essential for patients with Parkinson’s disease (PD) to regain activities of daily living. However, the underlying mechanisms of motor learning in PD remain unclear. To identify motor features that are distinctively manifested in PD during motor learning, we quantified a rich set of variables reflecting various aspects of the learning process in a virtual throwing task. While the performance outcome improved similarly over 3 days of practice for both PD patients and age-matched controls, further analysis revealed distinct learning processes between the two groups. PD patients initially performed with a slow release velocity and gradually increased it as practice progressed, whereas the control group began with an unnecessarily rapid release velocity, which they later stabilized at a lower value. Performance characteristics related to the timing of ball release and the inter-release interval did not show significant group differences, although they were modulated across practice in both groups. After one week, both groups retained the performance outcomes and underlying kinematics developed over practice. This study underscores the importance of analyzing the multi-faceted learning process to characterize motor skill learning in PD. The findings may provide insights into PD pathophysiology and inform rehabilitation strategies.

Decoding Motor Skills: Video Analysis Unveils Age-Specific Patterns in Childhood and Adolescent Movement

Motor skill development is crucial in human growth, evolving with the maturation of the nervous and musculoskeletal systems. Quantifying these skills, especially coordinative abilities, remains challenging. This study aimed to assess the performance of five motor tasks in children and adolescents using high-speed video analysis, providing data for movement and health professionals. Seventy-two volunteers were divided into three age groups: 27 first-grade primary school students (19 males and 8 females, aged 6.5 ± 0.5 years), 35 fourth-grade primary school students (16 males and 19 females, aged 9.2 ± 0.4 years), and 28 s-year middle school students (16 males and 12 females, aged 13.0 ± 0.3 years). Participants performed five motor tasks: standing long jump, running long jump, stationary ball throw, running ball throw, and sprint running. Each task was recorded at 120 frames per second and analyzed using specialized software to measure linear and angular kinematic parameters. Quantitative measurements were taken in the sagittal plane, while qualitative observations were made using a dichotomous approach. Statistical analysis was performed using the Kruskal–Wallis and Mann–Whitney tests with Bonferroni correction. Significant differences were observed across age groups in various parameters. In the standing long jump, older participants exhibited a longer time between initial movement and maximum loading. The running long jump revealed differences in the take-off angle, with fourth-grade students performing the best. Ball-throwing tests indicated improvements in the release angle with age, particularly in females. Sprint running demonstrated the expected improvements in time and stride length with age. Gender differences were notable in fourth-grade students during the running long jump, with females showing greater knee flexion, while males achieved better take-off angles. Video analysis effectively identified age-related and gender-specific differences in motor skill performance. The main differences were measured between first-grade primary school and second-year middle school students while gender differences were limited to all age groups. This method provides valuable insights into motor development trajectories and can be used by professionals to objectively assess and monitor the technical aspects of motor skills across different age groups.

Oculomotor functional connectivity associated with motor sequence learning.

Acquisition of learned motor sequences involves saccades directed toward the goal to gather visual information prior to reaching. While goal-directed actions involve both eye and hand movements, therole of brain areas controlling saccades during motor sequence learning is still unclear. This study aimed to determine whether resting-state functional connectivity of oculomotor regions is associated with behavioral changes resulting from motor sequence learning. We investigated connectivity between oculomotor control regions and candidate regions involved in oculomotor control and motor sequence learning. Twenty adults had brain scans before 3 days of motor task practice and after a 24-hour retention test, which was used to assess sequence-specific learning. During testing, both saccades and reaches were tracked. Stronger connectivity in multiple oculomotor regions prior to motor task practice correlated with greater sequence-specific learning for both saccades and reaches. A more negative connectivity change involving oculomotor regions from pre- to post-training correlated with greater sequence-specific learning for both saccades and reaches. Overall, oculomotor functional connectivity was associated with themagnitude of behavioral change resulting from motor sequence learning, providing insight into thefunction of the oculomotor system during motor sequence learning.

Enhancing perceptual, attentional, and working memory demands through variable practice schedules: insights from high-density EEG multi-scale analyses.

Contextual interference (CI) enhances learning by practicing motor tasks in a random order rather than a blocked order. One hypothesis suggests that the benefits arise from enhanced early perceptual/attentional processes, while another posits that better learning is due to highly activated mnemonic processes. We used high-density electroencephalography in a multi-scale analysis approach, including topographic analyses, source estimations, and functional connectivity, to examine the intertwined dynamics of attentional and mnemonic processes within short time windows. We recorded scalp activity from 35 participants as they performed an aiming task at three different distances, under both random and blocked conditions using a crossover design. Our results showed that topographies associated with processes related to perception/attention (N1, P3a) and working memory (P3b) were more pronounced in the random condition. Source estimation analyses supported these findings, revealing greater involvement of the perceptual ventral pathway, anterior cingulate and parietal cortices, along with increased functional connectivity in ventral alpha and frontoparietal theta band networks during random practice. Our results suggest that CI is driven, in the random compared to the blocked condition, by enhanced specific processes such as perceptual, attentional, and working memory processes, as well as large-scale functional networks sustaining more general attentional and executive processes.

Humanoid Robot-Assisted Learning for Level 1 Autistic Children: Developing Test Plans to Enhance Number Recognition Skills

Autism Spectrum Disorder (ASD) impacts the social, communication, and cognitive development of affected individuals. Level 1 autism, the mildest form of ASD, presents unique challenges in the acquisition of crucial skills such as number recognition, which serves as a foundational aspect of children's cognitive development. Recent studies have shown that humanoid robots can offer effective intervention strategies for children with autism, fostering learning in a structured, engaging, and interactive environment. This study aims to develop and evaluate test plans using humanoid robots to enhance number recognition skills in Level 1 children with autism. Based on the findings, a test plan was designed to address the unique learning needs of Level 1 children with autism in number recognition. Participants were selected based on specific criteria, ensuring a diverse and representative sample. The humanoid robot's capabilities and features were detailed, emphasizing its role in facilitating the test plan. The research methodology outlined the test plan components, implementation procedure, data collection, and analysis techniques. Results demonstrated that the humanoid robot-assisted test plan was effective in enhancing number recognition skills among Level 1 children with autism. The participants exhibited significant improvements in their abilities to identify and manipulate numbers, as well as increased engagement and motivation in learning tasks. The study also revealed that the interactive and supportive nature of the humanoid robot fostered a positive learning environment, which contributed to the observed improvements in number recognition skills. The implications of these findings extend to the broader field of autism intervention, highlighting the potential benefits of incorporating humanoid robots into educational programs for children with autism.

LEADERSHIP PRACTICES OF SCHOOL HEADS AND WORK TASK MOTIVATION AS PREDICTORS OF TEACHERS’ BEHAVIOR

This study determined the significant influence of school head leadership practices and work task motivation as predictors of teachers’ behaviour. The quantitative approach using the correlational technique and analysis was utilized in this study with a sample of 325 teachers from the elementary schools of Caraga District, Schools Division of the City of Davao Oriental. Sets of adapted survey questionnaires were used to obtain data from the respondents subjected to content validity and reliability analysis. The data were analyzed using the Mean, Pearson-r, and Multiple Regression Analysis. The results reveal that the leadership practices were rated very high, and work task motivation was also rated as high. At the same time, teacher behaviour was rated high. Moreover, a significant relationship existed between these variables. A significant relationship between leadership practices and teacher behaviour was significant. A significant relationship between work task motivation and teacher behaviour was also significant. The extent of the influence of predictor variables on teacher behaviour was proven significant in the study.&lt;p&gt; &lt;/p&gt;&lt;p&gt;&lt;strong&gt; Article visualizations:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;&lt;img src="/-counters-/soc/0789/a.php" alt="Hit counter" /&gt;&lt;/p&gt;

Do gender stereotype threats have a spillover effect on motor tasks among children? A mixed-model design investigation

ObjectivesThe stereotype threat effect has captivated social and sports psychology researchers for over two decades. However, many questions remain unanswered. This research was designed to explore the spillover effects of stereotype threat in motor tasks. DesignA mixed model design with within-between-subjects was utilized, with soccer performance and throwing scores serving as the dependent variables. MethodForty-two 10-year-old girls without mental or physical disabilities participated in the study and were randomly assigned into two groups: stereotype threat (ST) and nullified stereotype threat (NST). After measuring baseline performance in throwing and soccer tasks, the participants in the ST group received soccer-based stereotype induction. Afterwards, they performed 20 trials of soccer shooting. Half an hour later, the children were asked to perform 10 throws with the non-dominant hand. ResultsOur results indicated that inducing soccer-based stereotypes towards girls led to underperformance in soccer, however, this negative effect did not spill over onto subsequent task (i.e., throwing) which was unrelated to the induced stereotype. ConclusionsOur finding regarding the stereotype threat spillover effect is novel and provides more insight into the range of effects of stereotype threat within the motor domain. The findings encourage the researcher to practice caution regarding the generalizability of the stereotype threat spillover effect, especially in motor tasks.

A bi-consolidating model for joint relational triple extraction

Current methods to extract relational triples directly make a prediction based on a possible entity pair in a raw sentence without depending on entity recognition. The task suffers from a serious semantic overlapping problem, in which several relation triples may share one or two entities in a sentence. In this paper, based on a two-dimensional sentence representation, a bi-consolidating model is proposed to address this problem by simultaneously reinforcing the local and global semantic features relevant to a relation triple. This model consists of a local consolidation component and a global consolidation component. The first component uses a pixel difference convolution to enhance semantic information of a possible triple representation from adjacent regions and mitigate noise in neighbouring neighbours. The second component strengthens the triple representation based a channel attention and a spatial attention, which has the advantage to learn remote semantic dependencies in a sentence. They are helpful to improve the performance of both entity identification and relation type classification in relation triple extraction. After evaluated on several publish datasets, the bi-consolidating model achieves competitive performance. Analytical experiments demonstrate the effectiveness of our model for relational triple extraction and give motivation for other natural language processing tasks.

Advanced Neuromuscular Training Differentially Changes Performance on Visuomotor Reaction Tests and Single-leg Hop Tests in Patients with ACL Reconstruction.

Advanced neuromuscular training prepares patients with anterior cruciate ligament reconstruction (ACLR) for sport participation. Return-to-sport testing often includes single-leg hop tests, yet combining motor and cognitive tasks (i.e., dual-task) might reveal neurocognitive reliance. This study examined changes in performance on visuomotor reactions tests and single-leg hop tests following advanced neuromuscular training in patients with ACLR. The hypothesis was that performance would improve less on reaction tests than on single-leg hop tests. Quasi experimental, Pretest-Posttest. Twenty-five patients with ACLR (11 males) completed 10 sessions of advanced neuromuscular training and pre-and post-training testing. Reaction tests outcomes were from a platform and visual display. The double-leg reaction test involved touching target dots with either leg for 20 seconds; correct touches and errors were recorded. The single-leg reaction test involved hopping on the test leg to 10 target dots; hop time and errors were recorded. Single-leg hop tests included forward, triple, crossover triple, and timed hop; limb symmetry index was recorded. Effect sizes were calculated for corrected touches on the double-leg reaction test, surgical side hop time on the single-leg reaction test, and surgical side hop distance or time on single-leg hop tests. Correct touches on the double-leg reaction test significantly increased from pre- to post-training (20.4 +/- 4.3 vs.23.9 +/- 2.8, p<0.001). Hop time on the single-leg reaction test significantly decreased from pre- to post-training (Surgical leg 13.2 vs.12.3 seconds, non-surgical leg 13.0 vs.12.1 seconds, p=0.003). Mean errors did not significantly change on either reaction test (p> 0.05). Cohens d effect sizes in descending order was single-leg hop tests (d=0.9 to 1.3), double-leg reaction test (d=0.9), and single-leg reaction test (d=0.5). Motor performance improved after advanced neuromuscular training, but the effect size was less on visuomotor reaction tests than single-leg hop tests. The results suggest persistence of neurocognitive reliance after ACLR and a need for more dual-task challenges in training. 3.

Immersive virtual reality for learning exoskeleton-like virtual walking: a feasibility study

PurposeVirtual Reality (VR) has proven to be an effective tool for motor (re)learning. Furthermore, with the current commercialization of low-cost head-mounted displays (HMDs), immersive virtual reality (IVR) has become a viable rehabilitation tool. Nonetheless, it is still an open question how immersive virtual environments should be designed to enhance motor learning, especially to support the learning of complex motor tasks. An example of such a complex task is triggering steps while wearing lower-limb exoskeletons as it requires the learning of several sub-tasks, e.g., shifting the weight from one leg to the other, keeping the trunk upright, and initiating steps. This study aims to find the necessary elements in VR to promote motor learning of complex virtual gait tasks.MethodsIn this study, we developed an HMD-IVR-based system for training to control wearable lower-limb exoskeletons for people with sensorimotor disorders. The system simulates a virtual walking task of an avatar resembling the sub-tasks needed to trigger steps with an exoskeleton. We ran an experiment with forty healthy participants to investigate the effects of first- (1PP) vs. third-person perspective (3PP) and the provision (or not) of concurrent visual feedback of participants’ movements on the walking performance – namely number of steps, trunk inclination, and stride length –, as well as the effects on embodiment, usability, cybersickness, and perceived workload.ResultsWe found that all participants learned to execute the virtual walking task. However, no clear interaction of perspective and visual feedback improved the learning of all sub-tasks concurrently. Instead, the key seems to lie in selecting the appropriate perspective and visual feedback for each sub-task. Notably, participants embodied the avatar across all training modalities with low cybersickness levels. Still, participants’ cognitive load remained high, leading to marginally acceptable usability scores.ConclusionsOur findings suggest that to maximize learning, users should train sub-tasks sequentially using the most suitable combination of person’s perspective and visual feedback for each sub-task. This research offers valuable insights for future developments in IVR to support individuals with sensorimotor disorders in improving the learning of walking with wearable exoskeletons