Changes In Motor Performance Research Articles

Neurophysiological correlates of functional changes in upper limb motor performance after rtms in stroke survivors

Neurophysiological correlates of functional changes in upper limb motor performance after rtms in stroke survivors

Efficacy of a Task-Oriented Intervention for Children with a Dual Diagnosis of Specific Learning Disabilities and Developmental Coordination Disorder: A Pilot Study.

Task-oriented approaches are recommended for children with developmental coordination disorder (DCD) to address deficits in motor performance and reduce activity limitations. Although this approach is used in several settings, the efficacy of these approaches in children with in dual-diagnosis of specific learning disabilities (SLD) and DCD is less widely known. This study aims to determine the effect of a group-based intervention based on neuromotor task training (NTT) principles on the motor performance of children aged 6-10 years with SLD/DCD. A pre-post-test controlled study design was conducted in children with a primary diagnosis of specific learning disabilities (SLD). DCD status was confirmed based on clinical assessment. Children scoring ≤16th percentile on the Motor Assessment Battery for Children 2nd Edition (MABC-2), who also presented with a functional motor problem, according to the MABC checklist were considered as having DCD. Children were allocated to the NTT intervention group based on teachers' perceived notion of need and received two 45-60 min training sessions per week for nine weeks. Children allocated to the usual care (UC) group, received their planned occupational therapy and physical education. The MABC-2 was used to assess changes in motor performance. Our numbers confirm that it is crucial to identify the presence of motor coordination difficulties in children who have been diagnosed with SLD. A task-oriented training program based on NTT principles, presented in small groups, has a positive effect on the motor performance in learners with neurodevelopmental disorders and this effect was larger than in the usual care group. Although using a small group format in children with multiple neurodevelopmental disorders may be challenging for the therapists, it may be a way of delivering services to children in schools for special education. Children with DCD plus LSD show improvement in their motor skills by performing group-based NTT in the school environment. Group-based NTT shows a significant improvement in the TSS score of the MABC-2 compared to usual care. Children with DCD plus SLD show equal effect sizes after NTT intervention as DCD without SLD.

Improvements in fitness and motor performance from the first to fifth grade in Basel

Introduction
 A well-developed motor performance is one key aspect of being able to participate in organised sports and to establish and maintain lifelong physical activity. Furthermore, a good fitness is an early indicator of beneficial health in adult life. The development of motor performance and fitness can be influenced by many facets like education, environment, nutrition and family habits. It could be important to identify factors that are negatively associated with motor development and fitness in order to propose interventions tackling them or specifically targeting disadvantaged children. The aim of this study is to identify intrinsic and extrinsic factors associated with the magnitude of motor performance and fitness development from the first to fifth grade in children in the city of Basel.
 Methods
 Children were tested in the first and the fifth grade for motor performance and anthropometrics. Parents were asked in the first grade to fill out a questionnaire. Motor performance tests included 20-meter shuttle run, 20-meter sprint, balancing backwards and side hopping tasks. The questionnaire asked among other things about socio economic status (SES) of the household in seven categories (up to CHF 2,000 per month, 2,000-3,000, 3,000-4,000, 4,000-5,000, 5,000-7,000, 7,000-9,000 and more than 9,000). Age, sex, height, BMI and SES were linearly regressed with changes in motor performance while controlling for baseline performance and the other factors. Mean and standard deviations are presented for descriptive data and effect sizes (standardized beta coefficients) for regression results.
 Results
 Thousand five-hundred and sixty-four children were assessed in both grades and 418 questionnaires were returned. Children were 50% male, 7.4 (±0.4) years of age in first grade, BMI was 16.3 (±2.4) kg/m2, and SES was 5.4 (±1.8). Motor performance improved by 60.2 (±77.3)%, 57.9 (±134)%, 71.3 (±39.2)% and 14.1 (±7.45)% for shuttle run, balancing backwards, side hopping and sprint, respectively. The proportion of overweight and obese children increased from 18.8 (±3.9) to 25.8 (±4.4)% and from 10.4 (±3.0) to 13.3 (±3.4)%, respectively. Neither age (β < 0.12) nor SES (β < 0.08) were meaningfully related to improvements in motor performance or fitness. Girls showed slightly larger improvements in sprint (β = 0.12) and balance (β = 0.08) performance while boys had larger improvements in shuttle run (β = 0.39) and jumping (β = 0.14) performance. Girls also showed substantially larger gains in BMI than boys (β = 0.68). BMI in first grade was negatively associated with improvements in shuttle run (β = 0.23) and sprint (β = 0.17) performance, but also slightly with balancing (β = 0.07) and jumping (β = 0.08) performance.
 Discussion/Conclusion
 A high BMI in first grade is negatively associated with development of motor performance and fitness and respective children should receive additional attention. Fortunately, children from economically disadvantaged families or younger children at school entry, showed a normal development in motor performance and fitness. The difference between boys and girls could be related to different developments in body composition for body weight related parameters (jumping and fitness). Based on these results, targeting interventions (exercise or nutrition) at children with a high BMI in first grade might be advisable, regardless of SES, age or sex.

Limb loading enhances skill transfer between augmented and physical reality tasks during limb loss rehabilitation

BackgroundVirtual and augmented reality (AR) have become popular modalities for training myoelectric prosthesis control with upper-limb amputees. While some systems have shown moderate success, it is unclear how well the complex motor skills learned in an AR simulation transfer to completing the same tasks in physical reality. Limb loading is a possible dimension of motor skill execution that is absent in current AR solutions that may help to increase skill transfer between the virtual and physical domains.MethodsWe implemented an immersive AR environment where individuals could operate a myoelectric virtual prosthesis to accomplish a variety of object relocation manipulations. Intact limb participants were separated into three groups, the load control (CGLD; N=4), the AR control (CGAR; N=4), and the experimental group (EG; N=4). Both the CGAR and EG completed a 5-session prosthesis training protocol in AR while the CGLD performed simple muscle training. The EG attempted manipulations in AR while undergoing limb loading. The CGAR attempted the same manipulations without loading. All participants performed the same manipulations in physical reality while operating a real prosthesis pre- and post-training. The main outcome measure was the change in the number of manipulations completed during the physical reality assessments (i.e. completion rate). Secondary outcomes included movement kinematics and visuomotor behavior.ResultsThe EG experienced a greater increase in completion rate post-training than both the CGAR and CGLD. This performance increase was accompanied by a shorter motor learning phase, the EG’s performance saturating in less sessions of AR training than the CGAR.ConclusionThe results demonstrated that limb loading plays an important role in transferring complex motor skills learned in virtual spaces to their physical reality analogs. While participants who did not receive limb loading were able to receive some functional benefit from AR training, participants who received the loading experienced a greater positive change in motor performance with their performance saturating in fewer training sessions.

Baseline Measures of Cortical Inhibition Predict Motor Performance Changes after Exercise Interventions

<h3>Research Objectives</h3> To investigate the relationship of transcranial magnetic stimulation (TMS) measures on cortical inhibition before and after an exercise intervention in older adults. Our hypothesis is that higher levels of cortical inhibition would predict greater motor skill acquisition. We predicted that persons randomized to an aerobic spin exercise intervention would increase cortical inhibition and motor performance as compared to light strength training. <h3>Design</h3> The study design is randomized controlled trial with two groups investigating a balance and strength training intervention (both lasting 12-weeks or 36 sessions) against an Aerobic Cycling Intervention. The assessment sessions included behavioral testing, TMS taken at study baseline and after 12-weeks. <h3>Setting</h3> This project involved community dwelling older adults and was performed in a medical center. The main study sites were the Atlanta VA and Emory University. <h3>Participants</h3> We randomized 20 participants to either an exercise intervention or a balance and strength training group after obtaining informed consent. Participants were required to be over the age of 60 years and reportedly healthy at inclusion. This report is on 13 completers. <h3>Interventions</h3> Participants were randomized to either a 12-week interval aerobic spin cycling (HIIT spin) or a 12-week intervention involving light strength training both under supervised trainers thrice weekly for up to 45 minutes per session. <h3>Main Outcome Measures</h3> We acquired transcranial magnetic stimulation measures of: cortical excitability (motor threshold), Short intracortical inhibition, Long Intracortical Inhibition, Short Interhemispheric inhibition, long interhemispheric inhibition. Speed and accuracy of motor learning was the behavioral outcome. <h3>Results</h3> Baseline measures of SICI and LICI showed participants with higher levels of disinhibition showed better motor performance. We found no effect for group. Contrary to our hypothesis, individuals with greater increases in TMS inhibition showed lower motor skill performance after interventions. <h3>Conclusions</h3> We can conclude from the preliminary data that measures of cortical inhibition taken from TMS do show change associated with interventions in older adults and predict improvement in motor skill acquisition. Additional study is needed to identify the mechanisms of change in cortical inhibition. <h3>Author(s) Disclosures</h3> None.

Optimal design of linear switched reluctance motor for sea wave power generation

The switchless reluctance motor’s non-permanent magnet structure design ensures its high reliability in the marine environment; thus, it is a feasible solution for the generator of a sea wave power generation system. However, the corresponding thrust density and efficiency remain insufficient. This study focused on a new type of flat linear switched reluctance motor (LSRM), using the finite element software to establish a structural model, and optimized the design with the goal of improving the efficiency and energy density. The entropy method was adopted for sensitivity stratification to objectively select weights to avoid the influence of subjectively selected different proportional weights on the optimization results. Based on the entropy method, the sensitivity of different structural parameters was stratified, and the simulated annealing algorithm, response surface method, and single parameter scanning method were combined for optimization. Finally, the optimal structural size parameters of the motor were determined. Based on the two-dimensional finite element method, to simulate the electromagnetic performance of the reluctance motor under different operating conditions, such as thrust, loss, and efficiency, changes in motor performance before and after optimization were compared to verify the high power generation efficiency and energy density of the optimized linear motor.

Motor training is improved by concurrent application of slow oscillating transcranial alternating current stimulation to motor cortex

Physical exercise and neurorehabilitation involve repetitive training that can induce changes in motor performance arising from neuroplasticity. Retention of these motor changes occurs via an encoding process, during which rapid neuroplastic changes occur in response to training. Previous studies show that transcranial alternating current stimulation (tACS), a form of non-invasive brain stimulation, can enhance encoding of a cognitive learning task during wakefulness. However, the effect of tACS on motor processes in the awake brain is unknown. In this study, forty-two healthy 18–35 year old participants received either 0.75 Hz (active) tACS (or sham stimulation) for 30 min during a ballistic thumb abduction motor training task. Training-related behavioural effects were quantified by assessing changes in thumb abduction acceleration, and neuroplastic changes were quantified by measuring motor evoked potential (MEP) amplitude of the abductor pollicis brevis muscle. These measures were reassessed immediately after the motor training task to quantify short-term changes, and then 24 h later to assess longer-term changes. Thumb abduction acceleration in both active and sham stimulation conditions increased immediately after the motor learning, consistent with effective training. Critically, participants in the active group maintained significantly higher thumb acceleration 24 h later (t40 = 2.810, P = 0.044). There were no significant changes or inter-group differences in MEPs for both conditions. The results suggest that 0.75 Hz tACS applied during motor training enhances the effectiveness of motor training, which manifests as enhancement in longer-term task benefits.

Impact of Repetitive Transcranial Magnetic Stimulation to the Cerebellum on Performance of a Ballistic Targeting Movement.

This study aimed to investigate the effects of repetitive transcranial magnetic stimulation (rTMS) of the cerebellum on changes in motor performance during a series of repetitive ballistic-targeting tasks. Twenty-two healthy young adults (n = 12 in the active-rTMS group and n = 10 in the sham rTMS group) participated in this study. The participants sat on a chair in front of a monitor and fixed their right forearms to a manipulandum. They manipulated the handle with the flexion/extension of the wrist to move the bar on the monitor. Immediately after a beep sound was played, the participant moved the bar as quickly as possible to the target line. After the first 10 repetitions of the ballistic-targeting task, active or sham rTMS (1Hz, 900 pulses) was applied to the right cerebellum. Subsequently, five sets of 100 repetitions of this task were conducted. Participants in the sham rTMS group showed improved reaction time, movement time, maximum velocity of movement, and targeting error after repetition. However, improvements were inhibited in the active-rTMS group. Low-frequency cerebellar rTMS may disrupt motor learning during repetitive ballistic-targeting tasks. This supports the hypothesis that the cerebellum contributes to motor learning and motor-error correction in ballistic-targeting movements.

Changes in Motor Performance and BMI of Primary School Children over Time-Influence of the COVID-19 Confinement and Social Burden.

During the COVID-19 pandemic, physical inactivity and being overweight increased in children, especially those from lower socioeconomic backgrounds. Additionally, a decrease in motor performance has been increasingly reported; however, there is a lack of meaningful data on the relationship between these findings and socioeconomic status. Therefore, we examined the BMI, BMI z score, the prevalence of overweight/obesity, and motor performance (based on lateral jumping, the standing long jump, and the 6-min run) among three cohorts from timelines before (2016) and during the pandemic (2020, 2021), using a cohort sequential design. Our analysis revealed that all parameters examined showed a significant negative trend over time. For children with a low social burden, the trend was statistically detectable only for lateral jumping and the 6-min run. For children with a high social burden, the prevalence of overweight/obesity increased from 4.2% to 5.4% between 2016 and 2021. The prevalence of being underweight also increased from 3.4% to 4.3% during this time. Motor performance decreased from 11.3% to 12.3%, except in the standing long jump. Children with a high social burden showed significantly lower results (7.4% to 9.6%). Thus, our data confirm an increase in both measurements of overweight/obesity and underweight, as well as a decrease in motor performance under the pandemic conditions, especially in children from socioeconomically deprived backgrounds. These findings affirm the urgent need for action regarding health promotion measures, especially for children with high social burdens.

The simultaneous changes in motor performance and EEG patterns in beta band during learning dart throwing skill in dominant and non-dominant hand

Background: Although changes in performance during the learning of various sports skills have been studied, however, how these changes at the brain level is still unknown. The aim of this study was to investigate simultaneous changes in motor performance and EEG patterns in beta band during learning dart throwing skill in dominant and non-dominant hand. Methodology: The samples consisted of 14 non-athlete students with an average age of 23 ± 2.5, which were divided into two group dominant hand (7) and non-dominant hand (7). Repeated measures ANOVA were used to measure data at the execution level and changes in EEG activity. Results: The results of this study at the performance level showed a significant reduction in the absolute error of dart throwing and at the same time at the brain level increased EEG activity in frontal and parietal-posterior regions along with decreased central area activity in acquisition and retention stages in both groups (P<.05). Also, there was a significant difference between the activity of EEG pattern in the dominant and non-dominant hand groups except for two channels AF3 and PO4 (P<.05). Conclusion: In general, the results of this study showed that along with relatively constant changes in performance during dart skill learning, relatively constant changes in EEG activity pattern occur, so that the concept of motor learning is also visible at the brain level. Also, the results of this study supported the existence of the different motor program for dominant and non-dominant hand control in the conditions of bilateral transfer control.

Monitoring Glucose Concentrations in Children with Epilepsy on a Ketogenic Diet.

Ketogenic diet (KD) and pulsatile dexamethasone therapy (PDT) are commonly used in the treatment of children with drug resistant epilepsy. Potential side effects of the KD are hypoglycemia, whereas PDT might lead to hyperglycemia. One practical option to measure glucose concentrations regularly is the flash glucose monitoring system (FGM). In this single-center study in Germany, two pediatric patients with epilepsy (age: 6.0 and 6.8 years) received FGM from the beginning of the KD over six months, in the year 2020, and one patient (9.8 years) was observed for one month on PDT and switched to the KD thereafter. Glucose concentrations were measured by using an FGM system and capillary blood measurement. Seizure frequency, changes in cognition, motor performance, social behavior, and sleep quality were evaluated. The mean hypoglycemia rate per day (65 mg/dL and lower) declined significantly in patient 1 and 2 after three months. Patient 3 showed in total seven hyperglycemic events during PDT. Patient 1 became seizure free. Improvement of attention and memory performance were reported. FGM during the KD as a treatment for drug resistant epilepsies in childhood is a practical option to explore and to avoid hypoglycemia during the KD and hyperglycemia during PDT.

Development of fundamental motor skills between 2006 and 2016 in Dutch primary school children

ABSTRACT Background Fundamental Motor Skills (FMS) are important building blocks for children’s sport-participation and lifelong physical activity. In the last decade, several international studies have reported delays in the development of FMS. To get better insight into the Dutch situation and to provide future directions, this study examined the development of FMS in Dutch primary school children. Method The main goal of this study is to compare FMS of 11–12-year-old Dutch children in 2016 with scores of similarly-aged-children in 2006. In addition, gender, age, BMI were taken into account, to see whether changes in motor performance are related to these child characteristics. FMS-test scores on seven motor competence tests (balance, swing, jump, roll, shoot, throwing and catching, and tennis) from 1939 children in 2016 were set side by side with those of 1648 children in 2006. Temporal changes in motor competence scores were analyzed using regression-analysis. Results This cross-sectional study shows better results for the children in 2006 compared to similarly-aged-children in 2016. Lower scores were found on six out of seven tested FMS, with the largest declines on the object control skills tennis and throwing and catching. Only vaulting jump skills remained on the same level. Overall, children with a higher BMI scored lower on all tests, except for throwing and catching via the wall. On the balancing, jumping and tennis test, the gap with children with a lower BMI widened over the last decade. Girls showed a lower competence level on rolling, shooting and throwing and catching compared to boys. During the last decade, their performance on the tennis test decreased more than for boys. Conclusions Results of this study are alarming as diminishing motor skills are related to lower sport participation and poorer health outcomes. For the future generation, new interventions are needed to help children reach a sufficient proficiency level in FMS, to prevent or overcome the negative effects of lowered motor skills. Targeting FMS components during physical education and outside of school hours may potentially be a valuable strategy in reverting the lowering FMS levels amongst children.

Pain-induced changes in motor unit discharge depend on recruitment threshold and contraction speed.

At high forces, the discharge rates of lower- and higher-threshold motor units (MU) are influenced in a different way by muscle pain. These differential effects may be particularly important for performing contractions at different speeds since the proportion of lower- and higher-threshold MUs recruited varies with contraction velocity. We investigated whether MU discharge and recruitment strategies are differentially affected by pain depending on their recruitment threshold (RT), across a range of contraction speeds. Participants performed ankle dorsiflexion sinusoidal-isometric contractions at two frequencies (0.25 and 1 Hz) and two modulation amplitudes [5% and 10% of the maximum voluntary contraction (MVC)] with a mean target torque of 20%MVC. High-density surface electromyography recordings from the tibialis anterior muscle were decomposed and the same MUs were tracked across painful (hypertonic saline injection) and nonpainful conditions. Torque variability, mean discharge rate (MDR), DR variability (DRvar), RT, and the delay between the cumulative spike train and the resultant torque output (neuromechanical delay, NMD) were assessed. The average RT was greater at faster contraction velocities (P = 0.01) but was not affected by pain. At the fastest contraction speed, torque variability and DRvar were reduced (P < 0.05) and MDR was maintained. Conversely, MDR decreased and DRvar and NMD increased significantly during pain at slow contraction speeds (P < 0.05). These results show that reductions in contraction amplitude and increased recruitment of higher-threshold MUs at fast contraction speeds appear to compensate for the inhibitory effect of nociceptive inputs on lower-threshold MUs, allowing the exertion of fast submaximal contractions during pain.NEW & NOTEWORTHY Pain induces changes in motor performance, motor unit recruitment, and rate coding behavior that varies across different contraction speeds. Here we show that that pain reduces motor unit discharge rate and prolongs the neuromechanical delay at slow contraction speeds only. This new evidence suggests that there are differential nociceptive inhibitory effects across the motor unit pool, which allows fast submaximal contractions to be exerted despite the presence of pain.

Cortical preparatory activity during motor learning reflects visuomotor retention deficits after punishment feedback.

Previous studies have shown that reinforcement-based motor learning requires the brain to process feedback-related information after movement execution. However, whether reinforcement feedback changes how the brain processes motor preparation before movement execution is unclear. By using electroencephalography (EEG), this study investigates whether reinforcement feedback changes cortical preparatory activity to modulate motor learning and memory. Human subjects were divided in three groups [reward, punishment, control] to perform a visuomotor rotation task under different conditions that assess adaptation (learning) and retention (memory) during the task. Reinforcement feedback was provided in the form of points after each trial that signaled monetary gains (reward) or losses (punishment). EEG was utilized to evaluate the amplitude of movement readiness potentials (MRPs) at the beginning of each trial for each group during the adaptation and retention conditions of the task. The results show that punishment feedback significantly decreased MRPs amplitude during both task conditions compared to Reward and Control groups. Moreover, the punishment-related decrease in MRPs amplitude paralleled decreases in motor performance during the retention but not the adaptation condition. No changes in MRPs or motor performance were observed in the Reward group. These results support the idea that reinforcement feedback modulates motor preparation and suggest that changes in cortical preparatory activity contribute to the visuomotor retention deficits observed after punishment feedback.

Motor Performance in Male Youth Soccer Players: A Systematic Review of Longitudinal Studies.

The aim of this systematic review was to identify and synthesize the available information regarding longitudinal data addressing young soccer players’ motor performance changes. Following the Preferred Reporting Items for Systematic and Meta-analyses (PRISMA) statement, literature searches were performed in three databases: PubMed, ISI Web of Science and SCOPUS. The following descriptors were used: football, soccer, youth, young, player, athlete, physical performance, motor performance, longitudinal. The inclusion criteria were original articles in English with longitudinal data of young males (aged 10–18 years), with the aim to investigate motor performance serial changes. The initial search returned 211 records, and the final sample comprised 32 papers. These papers covered the European continent, and used mixed and pure longitudinal design with variation in sample size and age range. The reviewed studies tended to use different tests to assess the motor performance and aimed to identify changes in motor performance in several ways. In general, they indicated motor performance improvements with age, with a marked influence of biological maturity, body composition, and training stimuli. This review highlights the need for coaches and stakeholders to consider players’ motor performance over time whilst considering biological maturation, biological characteristics, and training stimuli.

Handwriting Readiness among Digital Native Kindergarten Students

Aims: Handwriting is an essential life skill, impacted by proficiency in visual-motor integration and fine motor control. The increase in the use of digital technology has changed the way children interact with their environments, and potentially, the development of the important requisite skills for handwriting. This study examined the “handwriting readiness” skills of children born in the digital age. Methods: 219 children in their first year of formal schooling (mean age = 5 years, 10 months), completed the Beery Buktenica Developmental Test of Visual Motor Integration (Beery-VMI) and the Bruininks-Oseretsky Test of Motor Proficiency, Second Edition (BOT-2) Short Form to assess visual motor integration, overall motor proficiency, and fine motor proficiency. Pencil grasp was also observed. Data analysis consisted of descriptive statistics and comparison to established normative data using summary t-tests. Results: Participants met the expected performance level on the Beery-VMI and the manual dexterity subtest of the BOT-2. However, overall motor proficiency on the BOT-2 for our sample was lower than published normative data. Further, 60.3% of participants used static pencil grasps. Conclusions: The findings prompt us to question the potential contribution of digital technology to changes in motor performance among children in the digital age.

Essential oil of Myrciaria tenella (DC.) O. Berg: effects of distillation time on its chemical composition and evaluation of its anti-inflammatory and antinociceptive effects

ABSTRACT The objective of the present study was to characterize the essential oil of Myrciaria tenella (MTEO) leaves, to determine the effects of distillation time (1 to 5 h), and to evaluate its action on acute pain and inflammation both in vivo and in vitro. MTEO was obtained by hydrodistillation for 4 h and 36 compounds were detected, mainly consisting of hydrocarbon terpenes such as β-pinene (21.46%), α-pinene (19.43%), E-caryophyllene (10.89%) and aromadendrene (9.17%). A high yield of α-pinene/β-pinene-rich MTEO was obtained after only 2 h of extraction. For in vivo biological assays, MTEO was administered to male Swiss mice, showing an action against hypernociception (acetic acid-induced abdominal writhing, formalin and Von Frey models) and inhibiting carrageenan-induced paw edema. Production of IL-6, TNF-α, IL-1β, PGE2 was reduced and production of IL-10 was increased, with no change in motor performance. MTEO also reduced cell production of NO and cytokines, in addition to inhibiting COX activity.

ANALISA UNJUK KERJA MOTOR INDUKSI 3 PHASA TERHADAP PENGARUH HARMONISA (THD) DENGAN PENAMBAHAN FILTER AKTIF MENGGUNAKAN MATLAB

Operating non-linear loads can cause harmonic distortion, one of which is aninduction motor. Harmonics can cause the system power quality content level to become worse.One way to reduce harmonics is with an active filter. Theemethodduseddin thissresearchhisstheSimulink method in Matlab. The addition of an active filter aims toreduceetheeharmonicccontent in thennetwork in order toosee theeeffect ofhharmonics ontttheperformanceeeof the 3 phase induction motor on rotation and torque. The results of simulationanalysis using Matlab show that active filters can reduce the harmonic content in the networkcompared to networks without using active filters. The decrease that occurred in THDI was11.88% in the Rrphase, 11.87% in theeSsphaseaand 11.88% in the Ttphase with a load of 3motors. There is no change in motor performance at rotation and torque, namely the rotation of1498 Rpm and torque of 0.4682 Nm.

Assessment of motor skill accuracy and coordination variability after application of local and remote experimental pain

ABSTRACT Motor learning is a relatively permanent change in motor performance. Also, one of the factors that can affect movement acquisition and movement patterns is pain and injury. The present study aims to investigate the effect of the induced local and remote pain during dart-throwing skill acquisition by examining motor skill accuracy and coordination variability. Three groups of 30 participants with a mean age of 18–25 were randomly assigned to local and remote pain or control groups. Capsaicin gel was applied to the pain groups for measuring the severity of pain using the Visual Analogue Scale (VAS). The results revealed that pain had no impact on dart-throwing skill acquisition, and there was no significant difference (p = 0.732) among the three groups at three stages of retention test. The results also showed that there was a significant difference among the three groups in terms of variability in shoulder-elbow (p = 0.025) and elbow-wrist joints (p = 0.000) in the deceleration and dart-throwing phases. The Central Nervous System seems to make adjustments when the task is associated with pain during the acquisition phase. Also, the groups with or without pain have notably various strategies, so differently, to perceive motor skills.

Differential Progression of Motor Dysfunction Between Male and Female Fragile X Premutation Carriers Reveals Novel Aspects of Sex-Specific Neural Involvement.

Expansions of the CGG repeat in the non-coding segment of the FMR1 X-linked gene are associated with a variety of phenotypic changes. Large expansions (>200 repeats), which cause a severe neurodevelopmental disorder, the fragile x syndrome (FXS), are transmitted from the mothers carrying smaller, unstable expansions ranging from 55 to 200 repeats, termed the fragile X premutation. Female carriers of this premutation may themselves experience a wide range of clinical problems throughout their lifespan, the most severe being the late onset neurodegenerative condition called “Fragile X-Associated Tremor Ataxia Syndrome” (FXTAS), occurring between 8 and 16% of these carriers. Male premutation carriers, although they do not transmit expanded alleles to their daughters, have a much higher risk (40–50%) of developing FXTAS. Although this disorder is more prevalent and severe in male than female carriers, specific sex differences in clinical manifestations and progress of the FXTAS spectrum have been poorly documented. Here we compare the pattern and rate of progression (per year) in three motor scales including tremor/ataxia (ICARS), tremor (Clinical Tremor Rating scale, CRST), and parkinsonism (UPDRS), and in several cognitive and psychiatric tests scores, between 13 female and 9 male carriers initially having at least one of the motor scores ≥10. Moreover, we document the differences in each of the clinical and cognitive measures between the cross-sectional samples of 21 female and 24 male premutation carriers of comparable ages with FXTAS spectrum disorder (FSD), that is, who manifest one or more features of FXTAS. The results of progression assessment showed that it was more than twice the rate in male than in female carriers for the ICARS-both gait ataxia and kinetic tremor domains and twice as high in males on the CRST scale. In contrast, sex difference was negligible for the rate of progress in UPDRS, and all the cognitive measures. The overall psychiatric pathology score (SCL-90), as well as Anxiety and Obsessive/Compulsive domain scores, showed a significant increase only in the female sample. The pattern of sex differences for progression in motor scores was consistent with the results of comparison between larger, cross-sectional samples of male and female carriers affected with the FSD. These results were in concert with sex-specific distribution of MRI T2 white matter hyperintensities: all males, but no females, showed the middle cerebellar peduncle white matter hyperintensities (MCP sign), although the distribution and severity of these hyperintensities in the other brain regions were not dissimilar between the two sexes. In conclusion, the magnitude and specific pattern of sex differences in manifestations and progression of clinically recorded changes in motor performance and MRI lesion distribution support, on clinical grounds, the possibility of certain sex-limited factor(s) which, beyond the predictable effect of the second, normal FMR1 alleles in female premutation carriers, may have neuroprotective effects, specifically concerning the cerebellar circuitry.