Functional Tasks Research Articles

Associations between capacity of cognitive control and sleep quality: a two-wave longitudinal study.

This longitudinal study explored the impact of the upper limit of cognitive control on the sleep quality of high school students. We collected data in two waves to examine four main variables: capacity of cognitive control (CCC), trait mindfulness, emotional distress and sleep quality. At the first time point (T1), trait mindfulness and emotional distress were measured by rating scales, and the CCC was evaluated by revised backward masking majority function task. Sleep quality was rated 5 months later (T2). The results indicated that: (1) the CCC was negatively correlated with trait mindfulness, and trait mindfulness was negatively correlated with emotional stress; (2) there was no simple mediation of either trait mindfulness or emotional distress in the relationship between CCC and sleep quality; (3) instead, the CCC was associated with poor sleep quality in a sequential mediation through trait mindfulness and then emotional stress. The research highlights the importance of trait mindfulness and emotional distress for addressing sleep problems in adolescents.

Psycholinguistics Study on the Interplay of Bilingualism on Selected Cognitive Functions Based on Threshold Hypotheses among Saudi International School Students

This study investigates the threshold hypothesis in Saudi international school students. While this hypothesis has been extensively researched in the West, its application in Arabic-speaking regions, particularly Saudi Arabia, remains unexplored. This paper compares the executive function (metalinguistic awareness, inhibitory control, attentional control, and working memory) differences between the three levels of bilinguals (balanced, dominant, and semi) in male secondary school students in Saudi Arabia. Participants took language tests (TOEFL for English, GCSE for Arabic) and four cognitive tasks (grammatical judgment task, Stroop Task, semantic and phonemic fluency task, and Backward-digit-recall task). A quantitative causal-comparative analysis concluded that there was no significant difference between the performance of balanced, dominant, and semi-bilinguals on executive function tasks, except for the phonemic task. However, the study showed that semi-bilinguals performed poorly in all cognitive tasks. Thus, balanced and dominant bilinguals perform equally in inhibitory control, mental flexibility, and metalinguistic and semantic tasks.

The relationship between SV2A levels, neural activity, and cognitive function in healthy humans: A [11C]UCB-J PET and fMRI study

Abstract Synaptic terminal density is thought to influence cognitive function and neural activity, yet its role in cognition has not been explored in healthy humans. We examined these relationships using [11C]UCB-J positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) in 25 healthy adults performing cognitive function tasks in the scanner. We found a significant positive association between synaptic terminal density, indicated by [11C]UCB-J PET distribution volume ratio (DVRcs), and neural activity during task switching (PLS-CA, second canonical component, r = 0.63, p = 0.043) with the thalamus-putamen data positively contributing to this relationship (PLS-CA loading 0.679, exploratory Pearson’s correlation r = 0.42, p = 0.044, uncorrected). Furthermore, synaptic terminal density predicted switch cost (PLS-R, R2 = 0.45, RMSE = 0.06, p = 0.022), with DVRcs negatively correlating with switch cost in key brain regions including the dorsolateral prefrontal cortex and posterior frontal cortex. Conversely, no significant relationships were observed between [11C]UCB-J DVRcs and neural activity or performance measures in the N-back working memory task, suggesting interindividual differences in synaptic terminal density may be more closely related to some cognitive functions and not others.

Impact of mobile phone usage on dynamic postural control among South Indian college students.

Smartphones are a technical marvel that rapidly evolved to play an important role in our lives. One downside to smartphone use is that it significantly worsens posture. It is believed that using a smartphone while walking increases the risk of cognitive decline and the loss of dynamic balance needed to perform functional tasks. The objective of the study was to determine the impact of smartphone usage on dynamic postural control among South Indian college students. The study was carried out in a private college with 400 invited students through online social media platforms. The four-square step test and SAS-SV were used to determine the impact of smartphone usage on dynamic postural control. The students were informed about the study process. A total of 250 participants were included based on the inclusion criteria. There was a high percentage of agreement on smartphone usage on dynamic postural control measured with SAS-SV, revealing statistical significance with a mean value of 41.532 and SD of 10.010886. The four-square step test with a mean value of 22.5 and SD of 1.8995878 also proved significant impact. A positive correlation was found between smartphone usage and dynamic postural control, which was analysed using Pearson's correlation coefficient of 0.90130. A significant correlation was noted between mobile usage and dynamic balance. Smartphones can have a negative impact on dynamic balance by distracting users from their surroundings and increase the risk of falls.

Linking Dementia Pathology and Alteration in Brain Activation to Complex Daily Functional Decline During the Preclinical Dementia Stages: Protocol for a Prospective Observational Cohort Study.

Progressive difficulty in performing everyday functional activities is a key diagnostic feature of dementia syndromes. However, not much is known about the neural signature of functional decline, particularly during the very early stages of dementia. Early intervention before overt impairment is observed offers the best hope of reducing the burdens of Alzheimer disease (AD) and other dementias. However, to justify early intervention, those at risk need to be detected earlier and more accurately. The decline in complex daily function (CdF) such as managing medications has been reported to precede impairment in basic activities of daily living (eg, eating and dressing). Our goal is to establish the neural signature of decline in CdF during the preclinical dementia period. Gait is central to many CdF and community-based activities. Hence, to elucidate the neural signature of CdF, we validated a novel electroencephalographic approach to measuring gait-related brain activation while participants perform complex gait-based functional tasks. We hypothesize that dementia-related pathology during the preclinical period activates a unique gait-related electroencephalographic (grEEG) pattern that predicts a subsequent decline in CdF. We provide preliminary findings showing that older adults reporting CdF limitations can be characterized by a unique gait-related neural signature: weaker sensorimotor and stronger motor control activation. This subsample also had smaller brain volume and white matter hyperintensities in regions affected early by dementia and engaged in less physical exercise. We propose a prospective observational cohort study in cognitively unimpaired older adults with and without subclinical AD (plasma amyloid-β) and vascular (white matter hyperintensities) pathologies. We aim to (1) establish the unique grEEG activation as the neural signature and predictor of decline in CdF during the preclinical dementia period; (2) determine associations between dementia-related pathologies and incidence of the neural signature of CdF; and (3) establish associations between a dementia risk factor, physical inactivity, and the neural signature of CdF. By establishing the clinical relevance and biological basis of the neural signature of CdF decline, we aim to improve prediction during the preclinical stages of ADs and other dementias. Our approach has important research and translational implications because grEEG protocols are relatively inexpensive and portable, and predicting CdF decline may have real-world benefits. DERR1-10.2196/56726.

Electromyographic activity of the ankle and foot during functional exercises and traditional exercises

IntroductionTraditional exercises using an elastic band are often standard in clinical practice to gain muscle strength. Additionally, functional exercises are considered more representative of functional tasks or sport. However, it is unclear whether functional exercises are comparable to traditional exercises in activating the ankle joint and foot. ObjectiveThe purpose of this study was to analyze the effects of functional exercise and traditional exercise on the muscle activity of the ankle joint and foot. MethodsThirty women participated in this study. Using surface electromyographic, muscle activation of the Tibialis Anterior (TA), Peroneus Longus (FL), Peroneus Short (FC), Gastrocnemius Medialis (GM) and Flexor Digitorum Shortus (FCD) was measured in nine exercises (dorsiflexion with an elastic band, plantar flexion with an elastic band, inversion with an elastic band, eversion with an elastic band, towel curl, standing plantar flexion, squats with an elastic band on the foot, diagonal propulsion and propulsion with peroneal stimulation). The muscle activation was normalized by the activation in maximum voluntary isometric contraction. ResultsFunctional exercises showed larger mean EMG amplitudes than the traditional exercises for all muscle groups (p > 0.05). ConclusionFunctional exercises provoked more activation compared with the traditional exercises. Functional exercises can be indicated to improve muscle function and functional task performance in populations that suffer dysfunction in ankle joint and foot.

Signal to noise ratio of masticatory muscle activity of functional and non-functional oral tasks.

Electromyographic activity (EMG) of masticatory muscles during wakefulness is understudied. It is unclear if single channel ambulatory EMG devices are sensitive enough to detect masticatory muscle activity (MMA) during wakefulness. To compare the MMA of various oral tasks recorded with a single channel EMG device ((Grindcare4-datalogger Prototype device) (GC4-β)) and a conventional EMG (cEMG) device. EMG activity of 30 standardised oral tasks was recorded unilaterally from the masseter and anterior temporalis muscle in 24 healthy volunteers using GC4-β and a cEMG device. To compare the EMG data, signal-to-noise ratios (SNR) were calculated as a way to normalise EMG activity across tasks. Analysis of variance was used to compare the SNR between the devices, muscles and oral tasks. SNR measured from GC4-β was overall significantly higher than the cEMG device (p =.001). The SNR for maximum voluntary contraction (MVC) was significantly higher than all other tasks (p <.001). SNR for temporalis with GC4-β was significantly higher for MVC, hard food, soft food, gum chewing (dominant side), rhythmic clenching and upper lip biting compared to the cEMG device (p <.021). The SNR for masseter with GC4-β was significantly higher for hard food and gum chewing (dominant side), rhythmic clenching, rhythmic biting of an object and yawning compared to the cEMG device (p <.022). This study provides novel insight into the EMG patterns of numerous oral tasks enhancing knowledge of physiological differences between the masticatory muscles. Further, single channel EMG devices can effectively measure the EMG activity of various oral tasks during wakefulness.

Balance, Landing Biomechanics, and Functional Movement Screen Characteristics With and Without Knee Exoskeleton in Military Soldiers.

A light-weight pneumatic-powered knee exoskeleton could augment mobility and lifting capabilities for a variety of occupational settings. However, added weight/bulkiness and artificially produced knee extension torque could compromise sensorimotor characteristics. Ten healthy participants conducted 3 visits within 10 days to the biomechanics laboratory. Participants were asked to complete the following tasks on each visit: single-leg balance, single-leg drop-landing, and select functional movement tasks. Balance characteristics (the ground reaction forces variability and center-of-pressure velocity) were derived from force plates while knee flexion angles during drop-landing and functional movement tasks were captured using a motion capture system. Descriptive statistics as well as paired t-tests or Wilcoxon signed-rank tests were used to compare between conditions. Significance was set at P < .05 a priori. During single-leg balance, the ground reaction force variabilities were significantly increased (P = .013-.019) and the center of pressure velocity was decreased (P = .001-.017) when wearing knee exoskeleton. During single-leg drop-landing, the exoskeleton condition showed lower knee flexion angles at the initial contact (P = .004-.021) and peak (P = .006-.010). Additionally, the peak vertical ground reaction force was higher in the exoskeleton condition (P = .007). During functional movement tasks, the exoskeleton condition showed less knee flexion range-of-motion during the overhead squat (P = .007-.033) and hurdle step-over (P = .004-.005). Participants exhibited stiffer landing technique with the exoskeleton. Given that these compromised sensorimotor characteristics have been associated with musculoskeletal injury risk, modifications to exoskeletons to promote softer landing and greater knee flexion range-of-motion during dynamic activities may be warranted.

Network and state specificity in connectivity-based predictions of individual behavior.

Predicting individual behavior from brain functional connectivity (FC) patterns can contribute to our understanding of human brain functioning. This may apply in particular if predictions are based on features derived from circumscribed, a priori defined functional networks, which improves interpretability. Furthermore, some evidence suggests that task-based FC data may yield more successful predictions of behavior than resting-state FC data. Here, we comprehensively examined to what extent the correspondence of functional network priors and task states with behavioral target domains influences the predictability of individual performance in cognitive, social, and affective tasks. To this end, we used data from the Human Connectome Project for large-scale out-of-sample predictions of individual abilities in working memory (WM), theory-of-mind cognition (SOCIAL), and emotion processing (EMO) from FC of corresponding and non-corresponding states (WM/SOCIAL/EMO/resting-state) and networks (WM/SOCIAL/EMO/whole-brain connectome). Using root mean squared error and coefficient of determination to evaluate model fit revealed that predictive performance was rather poor overall. Predictions from whole-brain FC were slightly better than those from FC in task-specific networks, and a slight benefit of predictions based on FC from task versus resting state was observed for performance in the WM domain. Beyond that, we did not find any significant effects of a correspondence of network, task state, and performance domains. Together, these results suggest that multivariate FC patterns during both task and resting states contain rather little information on individual performance levels, calling for a reconsideration of how the brain mediates individual differences in mental abilities.

Association of Racial Status and Training Language with Baseline Performance and Training Gains During Computerized Training of Technology-related Everyday Functional Skills In Older Adults

ObjectivesResearch consistently finds that lower baseline performance predicts greater gains with computerized training. Lower baseline performance can originate from many factors, including educational and environmental disadvantages, leading to reduced exposure to functional tasks. Across six computerized technology-related functional skills, baseline performance and training gains were compared across race and training language. DesignRandomized clinical trial. SettingAbout 14 community centers in New York City and Miami. ParticipantsParticipants aged 60–90 with diverse ethnic (52% Latinx) and racial (27% Black) status, trained in in English (60%) or Spanish (40%). InterventionRemotely delivered computerized cognitive and skills training (FUNSATTM) for an hour twice a week for up to 12 weeks. MeasurementsCompletion time across all 6 tests pre and post training. ResultsThe total sample included 42 Black English Speakers, 52 White English speakers, and 61 Spanish speakers. Spanish speakers had the poorest baseline performance on all tasks, underperforming English-speaking Latinx participants. However, Spanish speaking participants had the largest training gains. Lower MOCA scores predicted lower baseline performance and greater training gains across samples. Educational attainment predicted training gains only in the Spanish speakers. Despite education effects in this group, all improvements were statistically significant with large effect sizes. ImplicationsLower baseline performance of functional skills was a positive predictor of training gains and was efficiently reversed through training. Even participants who initially appeared more impaired achieved substantial gains, congruent with the results reported in psychiatric populations. Critically, low baseline competence should not be interpreted as reflecting negatively on potential training gains.

The effect of false cognitive feedback on subsequent cognitive task performance

ABSTRACT Introduction Previous research has found beliefs about oneself and one’s own abilities may have the potential to affect subsequent performance on a particular task. Additionally, providing false feedback about a particular characteristic or even about overall cognitive abilities may also affect performance on later tasks. However, it is unclear to what extent false positive or negative feedback about cognition will affect subsequent executive function task performance. In the present series of studies, we examined whether receiving negative false feedback about cognition would affect subsequent decision making and other executive function task performance. Method In Study 1, the participants (n = 115) received false feedback that they were either high or low in creative intelligence before completing a series of decision making tasks. In Study 2, the participants (n = 146) completed a similar false feedback paradigm before completing assessments of a range of executive functions. Results Across studies, we found limited evidence of a consistent pattern of how false feedback affects subsequent cognitive task performance, although receiving positive and negative feedback affected specific tasks. Conclusions Our results indicate that the influence of false feedback on task performance is variable and may depend on factors such as the specific task or executive function assessed. In clinical work, it is important to consider how patients may internalize feedback about their cognitive abilities, as the feedback, coupled with other factors such as level of insight, apathy, disinhibition, or prior perceptions regarding a diagnosis, may influence interpretations.

Strength and activity of the protractor and retractor muscles of the asymptomatic dyskinetic scapula

The role of scapular dyskinesis as a risk factor of shoulder injury has been largely discussed. However, most studies have focused on symptomatic patients and less is known on the asymptomatic dyskinetic scapula. Removing the confounding effects of the pathologies could contribute to better characterize the scapula dyskinesis. As muscle properties (strength, fatigue, nerve injury …) have been identified as causative factors of scapular dyskinesis, this study focuses specifically on characterizing the protractor and retractor muscles of the dyskinetic scapula. Thirteen asymptomatic dyskinetic volunteers were compared to eleven asymptomatic non-dyskinetic control volunteers. Muscle characteristics were evaluated in terms of maximal strength, fatigue resistance and electromyographic activity during a functional closed-chained task. The results did not identify kinematic or muscle activity significant differences between the dyskinetic and the control group even in fatigue conditions. However, the results demonstrated that protractors vs. retractors fatigue resistance ratios were imbalanced (<0.8) in the dyskinetic group and significantly lower than in the non-dyskinetic one. Our study suggests that that strength imbalances are not necessarily related to the presence of pain at the shoulder joint. These results demonstrated the importance to complete the clinical assessments of the scapula with strength evaluations even for asymptomatic sport practitioners.

Evaluation of the Margin of Stability during Gait Initiation in Young Healthy Adults, Elderly Healthy Adults and Patients with Parkinson's Disease: A Comparison of Force Plate and Markerless Motion Capture Systems.

Gait initiation (GI) is a functional task classically used in the literature to evaluate the capacity of individuals to maintain postural stability. Postural stability during GI can be evaluated through the "margin of stability" (MoS), a variable that is often computed from force plate recordings. The markerless motion capture system (MLS) is a recent innovative technology based on deep learning that has the potential to compute the MoS. This study tested the agreement between a force plate measurement system (FPS, gold standard) and an MLS to compute the MoS during GI. Healthy adults (young [YH] and elderly [EH]) and Parkinson's disease patients (PD) performed GI series at spontaneous (SVC) and maximum velocity (MVC) on an FPS while being filmed by a MLS. Descriptive statistics revealed a significant effect of the group (YH vs. EH vs. PD) and velocity condition (SVC vs. MVC) on the MoS but failed to reveal any significant effect of the system (MLS vs. PFS) or interaction between factors. Bland-Altman plot analysis further showed that mean MoS biases were zero in all groups and velocity conditions, while the Bayes factor 01 indicated "moderate evidence" that both systems provided equivalent MoS. Trial-by-trial analysis of Bland-Altman plots, however, revealed that differences of >20% between the two systems did occur. Globally taken, these findings suggest that the two systems are similarly effective in detecting an effect of the group and velocity on the MoS. These findings may have important implications in both clinical and laboratory settings due to the ease of use of the MLS compared to the FPS.

A greater modulation of the visual and fronto-parietal networks for children in a post-media versus pre-media exposure group.

Media use in children has exploded in the past several decades, most recently fuelled by portable electronic devices. This study aims to explore differences in functional brain connectivity in children during a story-listening functional MRI (fMRI) task using data collected before (1998) and after (2013) the widespread adoption of media. Cross-sectional data were collected from English-speaking 5- to 7-year-old children at Cincinnati Children's Hospital Medical Center, USA, of a functional MRI narrative comprehension task completed in 1998 (n = 22) or 2013 (n = 25). Imaging data were processed using a graph theory approach, focusing on executive functions, language and visual processing networks supporting reading. Group differences suggest more efficient processing in the fronto-parietal network in the pre-media group while listening to stories. A modulation of the visual and fronto-parietal networks for the post-media exposure group was found. Further studies are needed to assess effects over time in the more exposed group to discern a causal effect of portable devices on cognitive networks.

Attention control training and transfer effects on cognitive tasks

Attention control is the common element underlying different executive functions. The backward Masking Majority Function Task (MFT-M) requires intensive attention control, and represents a diverse situation where attentional resources need to be allocated dynamically and flexibly to reduce uncertainty. Aiming to train attention control using MFT-M and examine the training transfer effects in various executive functions, we recruited healthy young adults (n = 84) and then equally randomized them into two groups trained with either MFT-M or a sham program for seven consecutive days. Cognitive evaluations were conducted before and after the training, and the electroencephalograph (EEG) signals were recorded for the revised Attention Network Test (ANT-R), N-back, and Task-switching (TS) tasks. Compared to the control group, the training group performed better on the congruent condition of Flanker and the double-congruency condition of Flanker and Location in the ANT-R task, and on the learning trials in the verbal memory test. The training group also showed a larger P2 amplitude decrease and P3 amplitude increase in the 2-back task and a larger P3 amplitude increase in the TS task's repeat condition than the control group, indicating improved neural efficiency in two tasks' attentional processes. Introversion moderated the transfer effects of training, as indicated by the significant group*introversion interactions on the post-training 1-back efficiency and TS switching cost. Our results suggested that attention control training with the MFT-M showed a broad transfer scope, and the transfer effect was influenced by the form of training task. Introversion facilitated the transfer to working memory and hindered the transfer to flexibility.

Evaluating possible ‘next day’ impairment in insomnia patients administered an oral medicinal cannabis product by night: a pilot randomized controlled trial

Cannabis and its major constituents, Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD), are being widely used to treat sleep disturbances. However, THC can cause acute cognitive and psychomotor impairment and there are concerns that driving and workplace safety might be compromised the day after evening use. Here, we examined possible ‘next day’ impairment following evening administration of a typical medicinal cannabis oil in adults with insomnia disorder, compared to matched placebo. This paper describes the secondary outcomes of a larger study investigating the effects of THC/CBD on insomnia disorder. Twenty adults [16 female; mean (SD) age, 46.1 (8.6) y] with physician-diagnosed insomnia who infrequently use cannabis completed two 24 h in-laboratory visits involving acute oral administration of combined 10 mg THC and 200 mg CBD (‘THC/CBD’) or placebo in a randomised, double-blind, crossover trial design. Outcome measures included ‘next day’ (≥9 h post-treatment) performance on cognitive and psychomotor function tasks, simulated driving performance, subjective drug effects, and mood. We found no differences in ‘next day’ performance on 27 out of 28 tests of cognitive and psychomotor function and simulated driving performance relative to placebo. THC/CBD produced a small decrease (-1.4%, p=.016, d=-0.6) in accuracy on the Stroop-Colour Task (easy/congruent) but not the Stroop-Word Task (hard/incongruent). THC/CBD also produced a small increase (+8.6, p=.042, d=0.3) in self-ratings of Sedated at 10 h post-treatment, but with no accompanying changes in subjective ratings of Alert or Sleepy (p’s>0.05). In conclusion, we found a lack of notable ‘next day’ impairment to cognitive and psychomotor function and simulated driving performance following evening use of 10 mg oral THC, in combination with 200 mg CBD, in an insomnia population who infrequently use cannabis.

Brain reserve in midlife is associated with executive function changes across 12 years

We examined how brain reserve in midlife, measured by brain-predicted age difference scores (Brain-PADs), predicted executive function concurrently and longitudinally into early old age, and whether these associations were moderated by young adult cognitive reserve or APOE genotype. 508 men in the Vietnam Era Twin Study of Aging (VETSA) completed neuroimaging assessments at mean age 56 and six executive function tasks at mean ages 56, 62, and 68 years. Results indicated that greater brain reserve at age 56 was associated with better concurrent executive function (r=.10, p=.040) and less decline in executive function over 12 years (r=.34, p=.001). These associations were not moderated by cognitive reserve or APOE genotype. Twin analysis suggested associations with executive function slopes were driven by genetic influences. Our findings suggest that greater brain reserve allowed for better cognitive maintenance from middle- to old age, driven by a genetic association. The results are consistent with differential preservation of executive function based on brain reserve that is independent of young adult cognitive reserve or APOE genotype.

Timed up and go demonstrates strong interrater agreement and criterion validity as a functional test in geriatric dogs.

To measure interobserver agreement for 4 functional tasks and their summed geriatric functional score (GFS) and correlate tasks and GFS with client-specific outcome measurements (CSOMs): Canine Brief Pain Inventory (CBPI) pain severity, CBPI pain interference, and Liverpool Osteoarthritis in Dogs. 89 geriatric dogs were recruited between April and September 2023 from staff, friends, and clients of the Cornell University College of Veterinary Medicine with a median age of 11.0 years and weight of 26.4 kg. Dogs underwent 4 sequential functional tests: timed up and go (TUG), cavallettis, figure 8s, and down to stands. Two observers independently scored each dog. The GFS was calculated based on the summed scores of the individual tests. Additional information collected included signalment, weight, measurements reflecting the comorbidities of aging (body condition score and muscle condition score), and CSOMs. Strong interrater agreement was found for all functional tests. The TUG in seconds (sTUG) and figure 8s demonstrated significant (P < .05) moderate to strong correlations to all CSOMs. The GFS showed similar significant correlations with all CSOMs except CBPI pain severity; however, when correlating individual tests to CSOMs, only figure 8s and TUG were significantly contributing to GFS results. Receiver operating characteristic curve analysis defined highly functional dogs as those completing the sTUG in under 3.83 seconds. The sTUG represented the best test for geriatric function given it was objective, reliable, correlated well to CSOMs, and could help identify highly functioning dogs. The sTUG appears to be the first practical and reliable functional test of canine geriatric mobility.

PARAMETRIC IDENTIFICATION OF A MATHEMATICAL MODEL FOR THE COPPER MATTE CONVERSION PROCESS

The paper provides data on the construction of mathematical models using parametric identification of objects, as well as the development of algorithms that allow calculating optimal charge plans in production, and also addresses issues related to modeling and control of electric melting. As a result of the work, the issues of partial automation through channels have been solved: regulation of electric power, charge loading control, melt level measurement, research on mechanization and automation of smelting products, as well as theoretical, experimental and pilot industrial studies on automation of electric furnaces of non-ferrous metallurgy. This control system of the electrothermal furnace operates in open mode, solves individual functional tasks of process control and management and provides solutions to the problems of optimal control of the technological process of electric melting. The paper also discusses issues related to the automatic control of the electric power of electrothermal furnaces. The furnace is considered as an object of channel control: electrode deepening-electrode currents.

Exoskeleton-assisted training to enhance lower limb motor recovery in subacute stroke: does timing matter? A pilot randomized trial

BackgroundLower limb motor recovery, including abnormal muscle synergies, occurs mainly within the first 5–8 weeks after a stroke. This suggests the importance of delivering impairment-focused therapies, such as therapeutic robots that promote symmetric gait, during this time-sensitive period, following the principle of “the earlier, the better.”ObjectiveFirst, to compare early robotic training (ERT) with usual care (UC) against UC alone on restoring intralimb muscle synergies and interlimb symmetry during functional tasks; Second, to investigate whether ERT is superior to delayed robotic training (DRT) starting after the proposed time-sensitive period.MethodsThis observer-blinded, randomized pilot trial with crossover design involved 19 nonambulatory adults included within 14 days poststroke. Those allocated to ERT (N = 10) received immediately 4 weeks of training (16 sessions, 4× /week) with the Ekso GT® above UC and were compared with the DRT group (N = 9) who received UC alone at this point. Thereafter a 3-week UC period followed to investigate sustainability of ERT and the interventional roles were exchanged; at about week 8 poststroke DRT subjects started the same experimental robotic protocol and ERT subjects continued UC as controls. Outcomes included changes in Fugl-Meyer lower extremity scores (FM-LE) reflecting muscle synergies, weight-bearing asymmetry (WBA), and dynamic control asymmetry (DCA) during quiet standing. Functional ambulation category (FAC) was used to classify walking independence (cut-off ≥4).ResultsA trend toward earlier reacquisition of walking independence favoring ERT with UC over UC was not accompanied by differences in FM-LE, WBA, or DCA (first objective). Thereafter, DRT with UC did not yield any significant changes relative to UC, such that no between-group differences were found favoring restorative effects of ERT over DRT (second objective).ConclusionThis pilot trial shows the feasibility of investigating a wearable exoskeleton as an adjunct therapy in subacute stroke. Nevertheless, our preliminary findings suggest that motor recovery of lower limb muscle synergies was not enhanced by 4 weeks of robotic training to reduce compensations with the less-affected side, irrespective of the timing of application.Trial registrationClinicalTrials.gov, identifier: NCT03727919.