A task-dependent analysis of closed vs. open and fine vs. gross motor skills in handedness.

The traditional classifications of motor skills nature (open vs closed; fine vs gross) have not been considered in handedness investigations. Instead, previous research focused on comparing complex vs less complex motor behaviour, leaving a gap in the literature. We compared manual preference between different motor skill characteristics, namely: fine and closed (FC), gross and closed (GC) and gross and open (GO) tasks. The hand preference was assessed with the Global Lateral Preference Inventory in four hundred and forty participants (244 women) aged from 18 to 59 years old. By assessing the degree and direction of handedness in different motor skills, our results showed a stronger lateralization pattern for FC motor skills as compared to GC and GO, with GO also being less lateralized than GC. Our results expand those of previous investigations that used the motor skill complexity definitions by showing how handedness can also be modulated by the interaction between classic motor skills classifications. Future research should consider fine vs. gross and open vs. closed classifications when selecting tasks for analysis of asymmetries of preference.

Effect of disease, freezing of gait, and dopaminergic medication in the biomechanics of trunk and upper limbs in the gait of Parkinson's disease.

INTRODUCTION: Parkinson's disease (PD) causes gait abnormalities that may be associated with an arm swing reduction. Medication and freezing of gait (FoG) may influence gait characteristics. However, these comparisons do not consider differences in gait speed and clinical characteristics in individuals with PD. OBJECTIVE: This study aims to analyze the effect of FoG and medication on the biomechanics of the trunk and upper limbs during gait in PD, controlling for gait speed and clinical differences between groups. METHODS: Twenty-two people with a clinical diagnosis of idiopathic PD in ON and OFF medication (11 FoG), and 35 healthy participants (control) were selected from two open data sets. All participants walked on the floor on a 10-m-long walkway. The joint and linear kinematic variables of gait were compared: (1) Freezers and nonfreezers in the ON condition and control; (2) Freezers and nonfreezers in the OFF condition and control; (3) Group (freezers and nonfreezers) and medication. RESULTS: The disease affects the upper limbs more strongly but not the trunk. The medication does not significantly influence the joint characteristics but rather the linear wrist displacement. The FoG does not affect trunk movement and partially influences the upper limbs. The interaction between medications and FoG suggests that the medication causes more substantial improvement in freezers than in nonfreezers. CONCLUSION: The study shows differences in the biomechanics of the upper limbs of people with PD, FoG, and the absence of medication. The future rehabilitation protocol should consider this aspect.

Pistol shooting performance under pressure: Longitudinal changes in gaze behavior of male and female Army cadets.

We found evidence that Army cadets improved their gaze behavior and performance across time under high and low pressure in a shooting task. The purpose of the study was to determine if male and female cadets developed an optimal quiet eye (QE) onset, a longer QE duration, and decreased pupil diameter variability (PDV) over time under low (LP) and high pressure (HP) conditions. The study was carried out over four sessions, with intervals of 4.5 months. During each session, 16 men and 12 women, first-year cadets of The Brazilian Army Academy, performed ten pistol shots under counterbalanced LP and HP conditions. The cadets shot in the upright position and wore an eye-tracker. Shooting accuracy improved and did not differ for men and women in the LP condition, however during HP the women performed more poorly than the men in session 1 but improved to a level similar to the men in session 4. QE duration Pre (aiming) did not differ during LP, while during HP QE Post (execution) increased across the session for men and women. QE onset 2 (execution) occurred earlier for the men than women during LP, while during HP the women improved to a level similar to the men in sessions 3 and 4. PDV declined across sessions for men and women with the lowest values in sessions 3 and 4. The findings are discussed within social facilitation theory, which states the context of training affects the rate at which improvements in motor skills occur. The results show that women cadets can improve their shooting performance, quiet eye duration, quiet eye onset and pupil diameter variability to a level similar to men if three to four LP and HP training sessions are scheduled across approximately 12-18 months.

Muscle Recruitment Strategies in a Redundant Task: Age Differences Through Network Analyses.

There are numerous studies comparing young and old adults in terms of muscle coordination in standard tasks (e.g., walking, reaching) and small variations of them. These tasks might hide differences: individuals would converge to similar behavior as they practice these throughout life. Also, we are unaware of studies that considered the muscle recruitment nested dynamics. For this reason, our study evaluated how young and old women coordinate and control the movement system while performing an unusual redundant motor control task through the network physiology approach. We acquired electromyographic signals from nine leg muscles of the dominant and non-dominant limbs during maximum voluntary isometric contractions (knee extension and flexion) and co-contraction bouts. Our results showed that young participants presented higher peak torque output, with similar EMG variability, compared to older participants. Considering firing rate frequencies, old and young women demonstrated different traits for network clustering and efficiency for the task. Age seems to affect muscle coordination at higher frequencies, even with a similar number of muscle synergies, indicating that younger women might have more integrated synergies than older women. The findings also point to differential muscle coordination adaptability.

Postural adjustments and perceptual responses of Nordic running: concurrent effects of poles and irregular terrain.

PURPOSE: In the natural environment, humans must continuously negotiate irregular and unpredictable terrain. Recently, the poles have been extensively used during trial running events. However, we know little about how humans adjust posture and bilateral coordination to use poles in irregular terrain. Here, we compared kinematics, bilateral coordination and perceptual responses between regular (compact dust) and irregular terrain (medium-length grass) during running at preferred speed with and without poles. METHODS: In this transversal observational study, thirteen young healthy adults (8 men; mean ± SD; age 29.1 ± 8.0 years, body mass 76.8 ± 11.4 kg; height 1.75 ± 0.08 m) were evaluated during running at a self-selected comfortable speed with and without poles on regular and irregular terrains. RESULTS: Our results show that, despite more flexed pattern on lower-limb joints at irregular terrain, the usage of poles was not enough to re-stabilize the bilateral coordination. Also, the perceived exertion was impaired adding poles to running, probably due to more complex movement pattern using poles in comparison to free running, and the invariance in the bilateral coordination. CONCLUSION: Besides the invariability of usage poles on bilateral coordination and lower-limb kinematics, the runners seem to prioritize postural stability over lower limb stiffness when running in medium-length grass given the larger range of ankle and knee motion observed in irregular terrain. Further investigations at rougher/hilly terrains will likely provide additional insights into the neuromotor control strategies used to maintain the stability and on perceptual responses using poles during running.

Corrigendum: Ring attractor bio-inspired neural network for social robot navigation.

[This corrects the article DOI: 10.3389/fnbot.2023.1211570.].

Ring attractor bio-inspired neural network for social robot navigation.

Introduction: We introduce a bio-inspired navigation system for a robot to guide a social agent to a target location while avoiding static and dynamic obstacles. Robot navigation can be accomplished through a model of ring attractor neural networks. This connectivity pattern between neurons enables the generation of stable activity patterns that can represent continuous variables such as heading direction or position. The integration of sensory representation, decision-making, and motor control through ring attractor networks offers a biologically-inspired approach to navigation in complex environments. Methods: The navigation system is divided into perception, planning, and control stages. Our approach is compared to the widely-used Social Force Model and Rapidly Exploring Random Tree Star methods using the Social Individual Index and Relative Motion Index as metrics in simulated experiments. We created a virtual scenario of a pedestrian area with various obstacles and dynamic agents. Results: The results obtained in our experiments demonstrate the effectiveness of this architecture in guiding a social agent while avoiding obstacles, and the metrics used for evaluating the system indicate that our proposal outperforms the widely used Social Force Model. Discussion: Our approach points to improving safety and comfort specifically for human-robot interactions. By integrating the Social Individual Index and Relative Motion Index, this approach considers both social comfort and collision avoidance features, resulting in better human-robot interactions in a crowded environment.

Extroversion-Related Differences in Gaze Behavior during a Computer Task for Assessing Speed-Accuracy Trade-Off: Implications for Sensor-Based Applications.

The principle of Fitts' law explains that the difficulty of movement increases when targets are farther away and narrower in width, particularly when touching two parallel targets as quickly as possible. Understanding the differences in motor and gaze behaviors between extroverts and introverts when performing tasks that require speed and accuracy is crucial for the development of sensor-based interfaces for games and rehabilitation. This study aimed to investigate such differences in a computer task that assesses the speed-accuracy trade-off (Fitts' task). Twenty introverts and seventeen extroverts wore an eye tracker and an accelerometer attached to their hand while performing 12 trials through six levels of difficulty presented on a computer screen. The results showed that introverts had longer visual fixations at the higher difficulty levels and reduced pupil diameter variability when difficulty was intermediate, suggesting that their gaze behavior may be different from that of extroverts. However, no significant differences were found in the speed and accuracy performance or kinematic variables between extroverts and introverts. These findings have important implications for the design of interventions that require both speed and accuracy in movement, such as in the development of virtual reality/games for rehabilitation purposes. It is important to consider individual differences in motor and gaze behaviors, particularly in those who may struggle with longer visual fixations, for the design of sensor-based applications and to promote successful interventions and recovery.

Nivel de coordinación motriz de niños y niñas participantes del programa escuelas deportivas integrales del ministerio del deporte de Chile / Level of motor coordination in children participating in the integral sports schools program of chile's sports ministry

Hurtado Almonacid, J.G., Páez Herrera, J., Abusleme Allimant, R. Olate Gómez, F., Follegati Shore, S., Briones Oyanedel, V. y Mallea Díaz, V. (2023). Nivel de coordinación motriz de niños y niñas participantes del programa escuelas deportivas integrales del ministerio del deporte de Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 21(1), 1-16. Durante los últimos años se ha identificado que una baja coordinación motriz general incide en una baja participación en instancias de juego libre, actividades deportivas organizadas y libres. A su vez, un mejor dominio motriz se relaciona con un bajo nivel de sedentarismo. Por lo tanto, el objetivo de este artículo fue comparar el nivel de coordinación motriz general de niños y niñas participantes del componente de Iniciación Deportiva del programa ''Escuelas Deportivas Integrales'' (EDI) del Ministerio del Deporte Chile (''Crecer en Movimiento'' desde 2019), según región de procedencia. En relación con la muestra, se evaluaron 341 niños y niñas de ocho regiones del país (Antofagasta, Coquimbo, Valparaíso, O'Higgins, Metropolitana, Bío-Bío, Araucanía y Los Lagos) cuyas edades fluctuaron entre los 6 y 11 años de edad. Para recopilar información, se utilizó el instrumento 3JS, compuesto por siete tareas (3 de locomoción y 4 de control de objetos). Los resultados reflejaron que los niños poseen mejor rendimiento que las niñas en coordinación motriz general. Al agrupar las pruebas del test según el tipo de coordinación, también superan a las damas en locomoción y en control de objetos. Los niños y niñas de la región de Los Lagos obtienen mejor rendimiento en seis de las siete pruebas. Se concluye que los varones superan a las damas en las pruebas de coordinación locomotriz y control de objetos, así como también en las puntuaciones de coordinación motriz general.

Hurtado Almonacid, J.G., Páez Herrera, J., Abusleme Allimant, R. Olate Gómez, F., Follegati Shore, S., Briones Oyanedel, V. & Mallea Díaz, V. (2023). Level of motor coordination in children participating in the integral sports schools program of chile's sports ministry. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 21(1), 1-16. In recent years, it has been detected that generally low motor coordination results in low participation in free play situations, organized and free sports activities. In turn, a better motor mastery is consistent with a low level of sedentary lifestyle. Therefore, the objective of this article is to compare the level of general motor coordination in children that participate in the Sports Initiation component of the ''Integral Sports Schools'' (EDI) program of Chile's Sports Ministry (since 2019, ''Growing in Movement''), according to the regions they come from. Concerning the sample, the assessment covered 341 boys and girls from eight different regions in the country (Antofagasta, Coquimbo, Valparaíso, O'Higgins, Metropolitan Region, Bío-Bío, Araucanía and Los Lagos), in ages ranging from 6 to 11. The information was gathered through the 3JS instrument, made up of seven tasks (3 in locomotion and 4 in object control). The results showed that boys have a better performance than girls in terms of general motor coordination. When the test data were grouped according to the type of coordination, boys are also above girls in terms of locomotion and object control. Boys and girls from the Los Lagos region performed better in six of seven tests. In conclusion, boys outperform girls in the tests of motor coordination and object control, as well as in the scores of general motor coordination.

Hurtado Almonacid, J.G., Páez Herrera, J., Abusleme Allimant, R. Olate Gómez, F., Follegati Shore, S., Briones Oyanedel, V. e Mallea Díaz, V. (2023). Nível de coordenação motora das crianças que participam do programa escolas esportivas integrais do ministério do esporte do Chile. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 21(1), 1-16. Nos últimos anos, identificou-se que a baixa coordenação motora geral tem um impacto na baixa participação em atividades de jogos livres, atividades esportistas organizadas e livres. Por sua vez, uma melhor dominância motora está relacionada com um baixo nível de sedentarismo. Portanto, o objetivo deste artigo foi comparar o nível de coordenação motora geral das crianças participantes do componente de Iniciação Esportiva do programa "Escolas Esportivas Integrais" (EEI) do Ministério do Esporte do Chile ("Crescendo em Movimento" desde 2019), segundo a região de origem. Em relação à amostra, foram avaliadas 341 crianças de oito regiões do país (Antofagasta, Coquimbo, Valparaíso, O'Higgins, Metropolitana, Bío-Bío, Araucanía e Los Lagos) com idades entre 6 e 11 anos. Para a coleta de informações, foi utilizado o instrumento 3JS, composto por sete tarefas (3 de locomoção e 4 de controle de objetos). Os resultados mostraram que os meninos têm melhor desempenho do que as meninas na coordenação motora geral. Ao agrupar os testes de acordo com o tipo de coordenação, eles também superam as meninas em locomoção e controle de objetos. As crianças da região de Los Lagos tiveram melhor desempenho em seis dos sete testes. Conclui-se que os meninos superam as meninas nos testes de coordenação locomotora e controle de objetos, bem como nos escores gerais de coordenação motora.

Are Changes in Dynamic Knee Movement Control Related to Changes in Pain or Function in People With Knee Disorders? A Systematic Review and Meta-analysis.

OBJECTIVE: To study whether changes in dynamic knee valgus or varus were associated with changes in pain or function in people with knee disorders. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: We searched the MEDLINE, Embase, CINAHL, SPORTDiscus, Cochrane Library, and Web of Science, from inception up to January 2023. STUDY SELECTION CRITERIA: We included randomized controlled trials investigating the effects of nonsurgical (including nonpharmacological) interventions for knee disorders on frontal and transverse plane knee and hip movements during functional tasks, which reported pain and/or function outcomes. DATA SYNTHESIS: The relationship between changes in kinematics and pain/function was analyzed using a 2-stage structural equation modeling approach. RESULTS: From 42 202 records, 48 trials met the eligibility criteria. For people with patellofemoral pain (25 trials, n = 894), there was moderate evidence that changes in the knee and hip movements were significantly correlated with changes in pain and function (r= -0.69 to 0.73), except for the knee transverse plane movements and for the relationship between hip transverse plane movement and function. For people with knee osteoarthritis (15 trials, n = 704) and anterior cruciate ligament injuries (8 trials, n = 198), the evidence was limited and uncertain. CONCLUSION: The relationship between changes in movement control and clinical outcomes was consistent in people with patellofemoral pain. For people with knee osteoarthritis or anterior cruciate ligament injuries, there was a paucity of evidence that precluded a proper evaluation of the relationship between dynamic knee movement control, and pain and function. J Orthop Sports Phys Ther 2023;53(7):1-14. Epub: 18 April 2023. doi:10.2519/jospt.2023.11628.

A public data set of walking full-body kinematics and kinetics in individuals with Parkinson's disease.

Background: To our knowledge, there is no Parkinson's disease (PD) gait biomechanics data sets available to the public. Objective: This study aimed to create a public data set of 26 idiopathic individuals with PD who walked overground on ON and OFF medication. Materials and methods: Their upper extremity, trunk, lower extremity, and pelvis kinematics were measured using a three-dimensional motion-capture system (Raptor-4; Motion Analysis). The external forces were collected using force plates. The results include raw and processed kinematic and kinetic data in c3d and ASCII files in different file formats. In addition, a metadata file containing demographic, anthropometric, and clinical data is provided. The following clinical scales were employed: Unified Parkinson's disease rating scale motor aspects of experiences of daily living and motor score, Hoehn & Yahr, New Freezing of Gait Questionnaire, Montreal Cognitive Assessment, Mini Balance Evaluation Systems Tests, Fall Efficacy Scale-International-FES-I, Stroop test, and Trail Making Test A and B. Results: All data are available at Figshare (https://figshare.com/articles/dataset/A_dataset_of_overground_walking_full-body_kinematics_and_kinetics_in_individuals_with_Parkinson_s_disease/14896881). Conclusion: This is the first public data set containing a three-dimensional full-body gait analysis of individuals with PD under the ON and OFF medication. It is expected to contribute so that different research groups worldwide have access to reference data and a better understanding of the effects of medication on gait.

Can anxiety-like behavior and spatial memory predict the extremes of skilled walking performance in mice? An exploratory, preliminary study.

Introduction: Skilled walking is influenced by memory, stress, and anxiety. While this is evident in cases of neurological disorders, memory, and anxiety traits may predict skilled walking performance even in normal functioning. Here, we address whether spatial memory and anxiety-like behavior can predict skilled walking performance in mice. Methods: A cohort of 60 adult mice underwent a behavioral assessment including general exploration (open field), anxiety-like behavior (elevated plus maze), working and spatial memory (Y-maze and Barnes maze), and skilled walking performance (ladder walking test). Three groups were established based on their skilled walking performance: superior (SP, percentiles ≥75), regular (RP, percentiles 74-26), and inferior (IP, percentiles ≤25) performers. Results: Animals from the SP and IP groups spent more time in the elevated plus maze closed arms compared to the RP group. With every second spent in the elevated plus maze closed arms, the probability of the animal exhibiting extreme percentiles in the ladder walking test increased by 1.4%. Moreover, animals that spent 219 s (73% of the total time of the test) or more in those arms were 4.67 times more likely to exhibit either higher or lower percentiles of skilled walking performance. Discussion: We discuss and conclude anxiety traits may influence skilled walking performance in facility-reared mice.

Self-administered stretching exercises are as effective as motor control exercises for people with chronic non-specific low back pain: a randomised trial.

QUESTION: In people with chronic non-specific low back pain, what is the effect of self-administered stretching exercises relative to motor control exercises on pain intensity, disability, fear avoidance, global perceived effect and flexibility? DESIGN: Randomised trial with concealed allocation, intention-to-treat analysis and blinding of assessors. PARTICIPANTS: One hundred people with chronic non-specific low back pain. INTERVENTIONS: The self-stretching exercise group performed 6 stretches in 40-minute sessions. The motor control exercise group performed trunk stabilising exercises in 40-minute sessions. Both groups performed weekly supervised sessions for 8 weeks with one or more home sessions/week. OUTCOME MEASURES: The primary outcomes were pain intensity (0 to 10 scale) and disability (Oswestry Disability Index). The secondary outcomes were the Fear Avoidance Beliefs Questionnaire, global perceived effect, and the fingertip-to-floor test. Measures were taken at baseline and at 8, 13 and 26 weeks. RESULTS: On the 0 to 10 scale, the between-group difference in pain intensity was negligible, with a mean difference of roughly 0 (95% CI -1 to 1) at each time point. Similarly, the between-group difference on the 100-point disability scale was negligible: MD -1 (95% CI -3 to 1) at week 8, MD 1 (95% CI -1 to 3) at week 13 and MD 0 (95% CI -1 to 2) at week 26. The two interventions also had similar effects on the secondary outcomes. CONCLUSION: In people with chronic non-specific low back pain, self-stretching exercises had very similar effects to motor control exercises on pain intensity, disability, fear avoidance, global perceived effect and flexibility up to 18 weeks beyond the end of an 8-week program. Given the established effectiveness of motor control exercises, either intervention could be recommended to people with chronic low back pain. The choice of intervention might be directed by patient preference. REGISTRATION: NCT03128801.

The deep cerebellar nuclei to striatum disynaptic connection contributes to skilled forelimb movement.

Cerebellar-thalamo-striatal synaptic communication has been implicated in a wide range of behaviors, including goal-directed actions, and is altered in cerebellar dystonia. However, its detailed connectivity through the thalamus and its contribution to the execution of forelimb movements is unclear. Here, we use trans-synaptic and retrograde tracing, ex vivo slice recordings, and optogenetic inhibitions during the execution of unidirectional or sequential joystick displacements to demonstrate that the deep cerebellar nuclei (DCN) influence the dorsal striatum with a very high probability. We show that this mainly occurs through the centrolateral (CL), parafascicular (PF), and ventrolateral (VL) nuclei of the thalamus, observing that the DCN→VL and DCN→CL pathways contribute to the execution of unidirectional forelimb displacements while the DCN→PF and DCN→thalamo→striatal pathways contribute to the appropriate execution of forelimb reaching and sequential displacements. These findings highlight specific contributions of the different cerebellar-thalamo-striatal paths to the control of skilled forelimb movement.

The 180° Turn Phase of the Timed Up and Go Test Better Predicts History of Falls in the Oldest-Old When Compared With the Full Test: A Case-Control Study.

The 180° turn phase of the test may better differentiate the oldest-old regarding their history of falls. This is a case-control study designed to detect the ability of the 180° turn timed up and go (TUG) phase to detect a history of falls in the oldest-old. Sixty people aged 85 years and older were assessed in their homes. The single-task and dual-task TUG tests were performed using an inertial sensor (G-Walk). Sociodemographic data, physical activity levels, mental status, depressive symptoms, concern for falls occurrence, number of medicines in use, self-perception of balance, and the functional reach test were also assessed. The logistic regressions revealed the 180° turn phase of both the single-task and dual-task TUG was almost three times better than the full TUG test to detect a history of falls, thus providing insights that can be used to better assess functional mobility in the oldest-old.

Poststroke consequences upon optimization properties of postural sway during upright stance: a cross-sectional study.

BACKGROUND: The understanding of human postural control has advanced with the introduction of optimization process modeling. These models, however, only provide control parameters, rather than analytical descriptors of optimization processes. Here, we use a newly developed direct (pattern) search algorithm to investigate changes in postural optimization process in poststroke individuals. OBJECTIVE: This cross-sectional study investigated the optimization properties of postural stability during upright standing in poststroke individuals. METHODS: Twenty-nine poststroke and 15 healthy age-matched individuals underwent posturography with a force platform while standing for 60 s for acquisition of center-of-pressure data. Poststroke individuals were grouped depending on their weight-bearing (WB) pattern and their balance capability assessed through Berg Balance Scale (BBS). The optimization properties of postural stability were computed assuming the minimization of postural sway as cost function. RESULTS: The asymmetric WB poststroke group showed larger convergence rate toward the local minimum of postural sway than the symmetric WB group. Additionally, the low-balance capability group exhibited smaller values for averaged local minima and global minimum of postural sway coordinates compared with high-balance capability group. Significant correlations were found for BBS and the local minima and global minimum (Pearson's r ranged 0.378-0.424, P < 0.05). CONCLUSIONS: In summary, the optimization properties describing postural dynamic stability, steadiness, and global reference are altered in poststroke individuals with asymmetric WB pattern and low-balance capability.

Práctica mental, física o combinada en el desempeño y aprendizaje motor: una respuesta meta-analítica / Mental, physical or combined practice in motor performance and learning: a meta-analytical response

Jiménez Díaz, J., Morera-Castro, M., Chaves-Castro, K., Portuguez-Molina, P., Araya-Vargas, G. y Salazar, W. (2022). Práctica mental, física o combinada en el desempeño y aprendizaje motor: una respuesta meta-analítica. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(2), 1-37. En el proceso de adquisición de destrezas motrices la práctica es un elemento fundamental por que facilita el aprendizaje; esta práctica puede ser de dos tipos: física o mental. El objetivo del presente estudio fue determinar el tamaño de efecto de la práctica física (PF), práctica mental (PM) y la práctica combinada (PC) a lo largo del proceso de adquisición y retención en el desempeño de las destrezas motrices, utilizando el enfoque meta-analítico y el análisis de posibles variables moderadoras. Se utilizó el modelo de efectos aleatorios para calcular el tamaño de efecto (TE). Se incluyeron 24 estudios y se obtuvo un total de 150 TE, separados en cuatro grupos. En la fase de adquisición se encontró que la PF (TE = 1.75; n = 36; IC = 0.96,3.55; Q = 113; I2 = 92%), la PM (TE = 0.80; n = 36; IC = 0.50,1.09; Q = 108; I 2= 74%) y la PC (TE = 1.78; n = 22; IC = 1.39,2.18; Q = 167; I2 = 79%) mejoraron su desempeño; además, el grupo control (GC) mejoró el desempeño en la adquisición (TE = 0.18; n = 22; IC = 0.02,0.35; Q = 19; I 2= 0%). Una metarregresión indicó que solo la práctica física, mental y combinada predicen significativamente el TE. En la fase de retención, ni la PF (TE = -0.97; n = 9; IC = -0.41,0.02; Q = 12; I2 = 29%), la PM (TE = 0.62; n = 6; IC = -0.19,1.45; Q = 22; I2 = 83%), la PC (TE = -0.01; n = 14; IC = -0.26,0.25; Q = 23; I2 = 46%), ni el GC (TE = -0.15; n = 5; IC = -0.75,0.44; Q = 11; I2 = 66%) presentaron un cambio significativo. Se analizaron las posibles variables moderadoras. Los resultados sugieren que los tres tipos de práctica mejoran en el desempeño en la fase de adquisición; mientras que, en la etapa de retención, favorecen a mantener lo aprendido. La PM, no reemplaza la PF; no obstante, bajo algunas condiciones, se puede complementar la PF con PM.

Jiménez Díaz, J., Morera-Castro, M., Chaves-Castro, K., Portuguez-Molina, P., Araya-Vargas, G. y Salazar, W. (2022). Mental, physical or combined practice in motor performance and learning: a meta-analytical response. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(2), 1-37. Practice is a key element in the process of acquiring motor skills, because it facilitates learning. This practice can be of either of two types—physical or mental. The objective of the present study is to determine the extent of effect of physical practice (PF), mental practice (PM) and combined practice (PC) throughout the process of acquisition and retention in the performance of motor skills, using a meta-analytical approach and the analysis of possible moderating variables. The random effect model was used to calculate the extent of the effect (TE). A total 24 studies were included, and a total of 150 TE was obtained, separated in four groups. In the phase of acquisition, it was found that the PF (TE = 1.75; n = 36; IC = 0.96,3.55; Q = 113; I2 = 92%), the PM (TE = 0.80; n = 36; IC = 0.50,1.09; Q = 108; I2 = 74%) and the PC (TE = 1.78; n = 22; IC = 1.39,2.18; Q = 167; I2 = 79%) improved their performance; in addition, the control group (GC) improved the performance in acquisition (TE = 0.18; n = 22; IC = 0.02,0.35; Q = 19; I2 = 0%). A meta-regression indicated that only physical, mental and combined practice significantly predict the TE. In the retention phase, neither the PF (TE = -0.97; n = 9; IC = -0.41,0.02; Q = 12; I2 = 29%), the PM (TE = 0.62; n = 6; IC = -0.19,1.45; Q = 22; I2 = 83%), the PC (TE = -0.01; n = 14; IC = -0.26,0.25; Q = 23; I2 = 46%) or the GC (TE = -0.15; n = 5; IC = -0.75,0.44; Q = 11; I2 = 66%) showed a significant change. Possible moderating variables were analyzed. The results suggest that the three types of practice improve performance in the acquisition phase, while in the retention phase they help to keep what has been learned. The PM does not replace PF; however, PF can be complemented with PM under some conditions.

Jiménez Díaz, J., Morera-Castro, M., Chaves-Castro, K., Portuguez-Molina, P., Araya-Vargas, G. y Salazar, W. (2022). Prática mental, física ou combinada no desempenho e na aprendizagem motora: uma resposta metanalítica. PENSAR EN MOVIMIENTO: Revista de Ciencias del Ejercicio y la Salud, 20(2), 1-37. No processo de aquisição de destrezas motoras, a prática é um elemento fundamental porque facilita o aprendizado; esta prática pode ser de dois tipos: física ou mental. O objetivo do presente estudo foi determinar o tamanho do efeito da prática física (PF), da prática mental (PM) e da prática combinada (PC) durante todo o processo de aquisição e retenção do desempenho das destrezas motoras, usando a abordagem metanalítica e a análise de possíveis variáveis moderadoras. Foi utilizado o modelo de efeitos aleatórios para calcular o tamanho do efeito (TDE). Vinte e quatro estudos foram incluídos e obtidos um total de 150 TDEs, separados em quatro grupos. Na fase de aquisição, PF (TDE = 1,75; n = 36; IC = 0,96,3,55; Q = 113; I2= 92%), PM (TDE = 0,80; n = 36; IC = 0,50,1,09; Q = 108; I 2= 74%) e CP(TDE = 1,78; n = 22; IC = 1,39,2,18; Q = 167; I 2 = 79%) melhoraram seu desempenho; além disso, o grupo de controle (GC) melhorou seu desempenho na aquisição(TDE = 0,18; n = 22; IC = 0,02,0,35; Q = 19; I 2= 0%). Uma meta-regressão indicou que apenas a prática física, mental e combinada prediz significativamente o TDE. Na fase de retenção, nem PF (TDE = -0,97; n = 9; IC = -0,41,0,02; Q = 12; I2= 29%), PM (TDE = 0,62; n = 6; IC = -0,19,1,45; Q = 22; I2 = 83%), PC (TDE = -0,01; n = 14; IC = -0,26,0,25; Q = 23; I2 = 46%), nem o GC (TDE = -0,15; n = 5; IC = -0,75,0,44; Q = 11; I2= 66%) apresentou uma mudança significativa. Foram analisadas as possíveis variáveis moderadoras. Os resultados indicam que os três tipos de prática melhoram o desempenho na fase de aquisição, enquanto na fase de retenção, eles melhoram a retenção do que foi aprendido. A PM não substitui a PF; no entanto, sob algumas condições, a PF pode ser complementada com a PM.

Electrophysiological and functional signs of Guillain-Barré syndrome predicted by a multiscale neuromuscular computational model.

Objective.The diagnosis of nerve disorders in humans has relied heavily on the measurement of electrical signals from nerves or muscles in response to electrical stimuli applied at appropriate locations on the body surface. The present study investigated the demyelinating subtype of Guillain-Barré syndrome using multiscale computational model simulations to verify how demyelination of peripheral axons may affect plantar flexion torque as well as the ongoing electromyogram (EMG) during voluntary isometric or isotonic contractions.Approach.Changes in axonal conduction velocities, mimicking those found in patients with the disease at different stages, were imposed on a multiscale computational neuromusculoskeletal model to simulate subjects performing unipodal plantar flexion force and position tasks.Main results.The simulated results indicated changes in the torque signal during the early phase of the disease while performing isotonic tasks, as well as in torque variability after partial conduction block while performing both isometric and isotonic tasks. Our results also indicated changes in the root mean square values and in the power spectrum of the soleus EMG signal as well as changes in the synchronization index computed from the firing times of the active motor units. All these quantitative changes in functional indicators suggest that the adoption of such additional measurements, such as torques and ongoing EMG, could be used with advantage in the diagnosis and be relevant in providing extra information for the neurologist about the level of the disease.Significance.Our findings enrich the knowledge of the possible ways demyelination affects force generation and position control during plantarflexion. Moreover, this work extends computational neuroscience to computational neurology and shows the potential of biologically compatible neuromuscular computational models in providing relevant quantitative signs that may be useful for diagnosis in the clinic, complementing the tools traditionally used in neurological electrodiagnosis.

The flavonoid kaempferol protects the fruit fly Drosophila melanogaster against the motor impairment produced by exposure to the insecticide fipronil.

Exposure to pesticides across species has been associated with cognitive and motor impairments. As the problem impacts ecosystem stability, food production and public health, it is urgent to develop multifactorial solutions, from regulatory legislation to pharmacological alternatives that ameliorate the impairments. Fipronil, a commonly used insecticide, acts as a GABAA receptor (GABAAR) antagonist and induces motor impairments in vertebrates and invertebrates. Here, we hypothesized that kaempferol, a secondary metabolite derived from plants, acting as an allosteric modulator of GABAARs, would protect against the negative effects induced by the administration of fipronil in adults of the fruit fly Drosophila melanogaster. We further evaluated our hypothesis via co-administration of flumazenil, a competitive antagonist on the GABAAR, and through in silico analyses. We administered kaempferol prophylactically at three concentrations (10, 30 and 50 µmol l-1) and evaluated its protective effects against motor impairments induced by fipronil. We then used a single dose of kaempferol (50 µmol l-1) to evaluate its protective effect while administering flumazenil. We found that oral administration of fipronil impaired motor control and walking ability. In contrast, kaempferol was innocuous and protected flies from developing the motor-impaired phenotype, whereas the co-administration of flumazenil counteracted these protective effects. These results are supported by the binding of the ligands with the receptor. Together, our results suggest that kaempferol exerts a protective effect against fipronil via positive allosteric modulation of GABAARs, probably within brain areas such as the central complex and the mushroom bodies. These findings further support current attempts to use metabolites derived from plants as protectors against impairments produced by pesticides.