Motor learning and tDCS: A systematic review on the dependency of the stimulation effect on motor task characteristics or tDCS assembly specifications.

TDCS is one of the most commonly used methods among studies with transcranial electrical stimulation and motor skills learning. Differences between study results suggest that the effect of tDCS on motor learning is dependent on the motor task performed or on the tDCS assembly specification used in the learning process. This systematic review aimed to analyze the tDCS effect on motor learning and verify whether this effect is dependent on the task or tDCS assembly specifications. Searches were performed in PubMed, SciELO, LILACS, Web of Science, CINAHL, Scopus, SPORTDiscus, Cochrane Central Register of Controlled Trials (CENTRAL), Embase, and PsycINFO. Articles were included that analyzed the effect of tDCS on motor learning through pre-practice, post-practice, retention, and/or transfer tests (period ≥24 h). The tDCS was most frequently applied to the primary motor cortex (M1) or the cerebellar cortex (CC) and the majority of studies found significant stimulation effects. Studies that analyzed identical or similar motor tasks show divergent results for the tDCS effect, even when the assembly specifications are the same. The tDCS effect is not dependent on motor task characteristics or tDCS assembly specifications alone but is dependent on the interaction between these factors. This interaction occurs between uni and bimanual tasks with anodal uni and bihemispheric (bilateral) stimulations at M1 or with anodal unihemispheric stimulations (unilateral and centrally) at CC, and between tasks of greater or lesser difficulty with single or multiple tDCS sessions. Movement time seems to be more sensitive than errors to indicate the effects of tDCS on motor learning, and a sufficient amount of motor practice to reach the "learning plateau" also seems to determine the effect of tDCS on motor learning.

Freezing Degrees of Freedom During Motor Learning: A Systematic Review.

According to Bernstein, the central nervous system solution to the human body's enormous variation in movement choice and control when directing movement-the problem of degrees of freedom (DF)-is to freeze the number of possibilities at the beginning of motor learning. However, different strategies of freezing DF are observed in literature, and the means of selection of the control strategy during learning is not totally clear. This review investigated the possible effects of the class and objectives of the skill practiced on DF control strategies. The results of this review suggest that freezing or releasing the DF at the beginning of learning does not depend on the class (e.g., discrete skill class: football kick, dart throwing; continuous skill class: athletic march, handwriting) or objective of the skill (e.g., balance, velocity, and accuracy), in isolation. However, an interaction between these two skill elements seems to exist and influences the selection of the DF control strategy.

Beyond handedness: assessing younger adults and older people lateral preference in six laterality dimensions.

Lateral preference is influenced by many different factors. Although studies that assessed handedness contributed greatly to our understanding of the phenomenon, looking to other dimensions of motor laterality, such as lower limbs, trunk, visual and hearing preference, may be an interesting strategy to further advance in the field. Comparing different age groups with a complete inventory also contributes to understanding the ageing impact on these variables. Our aim, therefore, was to assess six motor laterality dimensions in younger adults and older people. Two hundred subjects participated in this study (102 adults, 30.6 ± 11.2 years old, and 98 elders, 70.4 ± 7.22 years old) and lateral preference was assessed by the Global Lateral Preference Inventory. We verified significant differences between groups in all dimensions, except the visual one, with proportionally stronger right preference in the older group. Compared to other dimensions, higher frequency of ambidexterity was observed in trunk, hearing and visual preference for both groups. These results might indicate that lateral preference is, indeed, multifactorial, being affected by ageing, task complexity and other possible related aspects.

Procedures of assessment on the quantification of thoracic kyphosis and lumbar lordosis by radiography and photogrammetry: A literature review.

The quantification of thoracic kyphosis and lumbar lordosis can be assessed in different ways; among them radiography and photogrammetry. However, the assessment procedures are not consistent in the literature for either method. The objective of this study was to conduct a literature review about postural assessment through radiography and photogrammetry, for delineating the procedures for both methods. In total 38 studies were selected by an online search in the MEDLINE and LILACS databases with the keywords: radiograph and posture, postural alignment, photogrammetry or photometry or biophotogrammetry. For the radiographic method, the results showed divergences in arm positioning and in the calculation of thoracic and lumbar angles. The photogrammetry demonstrated differences in relation to the camera, tripod, plumb line and feet positioning, angle calculation, software utilization, and the use of footwear. Standardization is proposed for both methods to help establish normative values and comparisons between diagnoses.

Preferência lateral percebida e diagnosticada em adolescentes / Lateral perceived and diagnosed preference in teenagers / Preferencia lateral percibida en adolescentes diagnosticados

Resumo O estudo analisou a percepção e a preferência lateral global de adolescentes (11-15 anos). Para tal, 153 adolescentes foram submetidos ao inventário de preferência lateral global (Iplag). Os participantes foram classificados como "moderadamente destros" na preferência lateral global percebida. A preferência lateral diagnosticada classificou os participantes como fortemente destros para membros superiores, membros inferiores, audição e visão e como moderadamente destros para tronco. Portanto, os adolescentes apresentaram-se como fortemente destros para preferência lateral global. Os escores de coerência entre a preferência lateral percebida e a preferência lateral diagnosticada demonstraram que os participantes têm grande conhecimento sobre sua preferência lateral.

Abstract The study analyzed the global lateral perception and preference of teenagers (11-15 years old). Within this scope, the study involved 153 teenagers, which were submitted to answer the Global Lateral Preference Inventory (Iplag). The participants were classified as "moderate right-handed" for perceived global lateral preference. In relation to lateral preference, they were classified as "strong right-handed" for the upper limbs, lower limbs, hearing and vision, and "moderate right-handed" for the trunk. Thus, the teenagers were classified as "strong right-handed" for the global lateral preference. The scores of consistency between lateral preference and perceived lateral preference showed that participants had great knowledge about their lateral preference.

Resumen El estudio analizó la percepción global lateral y la preferencia de los adolescentes (11-15 años). En este ámbito, en el estudio participaron 153 adolescentes, los cuales respondieron el Inventario Global de Preferencia Lateral (IPLAG). Los participantes se clasificaron como "moderadamente diestros" en la preferencia global lateral percibida. En relación con la preferencia lateral, se los clasificó como "fuertemente diestros" de los miembros superiores, miembros inferiores, audición y visión, y "moderado diestros" del tronco. Por lo tanto, a los adolescentes se los clasificó como "fuertemente diestros" de la preferencia lateral global. Las puntuaciones de la coherencia entre la preferencia lateral y la preferencia lateral percibida mostró que los participantes conocían muy bien su preferencia lateral.

Efeito da restrição espacial do ambiente na preferência manual em tarefa de alcance em adultos jovens / Effect of spatial constraint of the environment on the hand preference in reaching task in young adults / Efecto de la restricción espacial del entorno en la preferencia manual en una tarea de alcance en adultos jóvenes

Resumo A preferência manual (direção e magnitude) na tarefa de alcançar em adultos foi analisada em função da localização espacial de um objeto no ambiente. Trinta participantes fizeram a tarefa de alcançar um cilindro, devendo-se escolher apenas uma das mãos para fazer a tarefa, a 50 cm de distância em cinco posições diferentes em relação ao plano sagital do participante. Duas condições foram cumpridas: conforto (sem restrição da velocidade) e velocidade (movimento feito o mais rapidamente possível). Anova de Friedman apontou diferença (X230,9 = 122,17; p < 0,001) e o teste de Wilcoxon apontou maiores escores nas posições de 90°, 120° e 150° em comparação com 30° e 60° para ambas as condições (p < 0,01) demonstrando alcances ipsilaterais. Tais resultados foram explicados pela restrição biomecânica para fazer a tarefa, modulando a preferência manual, de acordo com a localização espacial dos objetos no ambiente.

Abstract The manual preference in a reaching task in adults was analyzed according to the spatial location of an object in the environment. Thirty participants performed the task of reaching a cylinder, with one hand, at 50 cm distance in five different positions in relation to the sagittal plane of the participant. Two conditions were performed: comfort and speed. Friedman' s ANOVA showed difference (X230,9 = 122.17; p < 0.001) and the Wilcoxon' s test showed higher scores at positions 90°, 120° and 150° in comparison 30° and 60°, for both conditions (p < 0.01) showing ipsilateral reaches. These results were explained by the biomechanics restriction to perform the task, modulating the manual preference, according to the spatial location of objects in the environment.

Resumen Se analizó la preferencia manual en una tarea de alcance en adultos en función de la ubicación espacial de un objeto en el entorno. Treinta participantes realizaron la tarea de alcanzar un cilindro, con una sola mano, a una distancia de 50 cm en cinco posiciones diferentes en relación con el plano sagital del participante. Dos condiciones se cumplieron: comodidad y velocidad. La prueba ANOVA de Friedman mostró una diferencia (χ230,9 = 122,17; p < 0,001) y la prueba de Wilcoxon mostró puntuaciones más altas en las posiciones de 90̊, 120̊ y 150̊ en comparación con las de 30̊ y 60̊, en ambas condiciones (p < 0,01), lo que demostró alcances ipsilaterales. Estos resultados se debieron a la biomecánica de restricción para realizar la tarea mediante la modulación de la preferencia manual, de acuerdo con la ubicación espacial de los objetos en el entorno.

Reprodutibilidade intra avaliador e interavaliadores na identificação digital da posição dos marcadores de referência na avaliação postural de fotogrametria / Intra and inter-rater reproducibility in digital identification of the position of the reference markers on postural evaluation by photogrammetry

O processo de identificação dos referenciais anatômicos em imagens (digitalização) na avaliação postural por fotogrametria, pode ser fonte de erro e, assim, influenciar a reprodutibilidade das medidas. O presente estudo analisou a reprodutibilidade inter e intra-avaliadores na identificação da posição dos marcadores no processo de digitalização na avaliação postural por fotogrametria. Trinta voluntários participaram do estudo, sendo 15 homens e 15 mulheres com idade média de 25 anos (DP=5,8). Foram identificados por um avaliador previamente treinado os processos das vértebras C7, T12 e L5 de cada participante por meio do método de palpação e colocação de marcadores externos seguido da realização de sessões de fotos. Os ângulos torácicos e lombares foram calculados pela identificação destes marcadores externos nas imagens por meio do software SAPO. Para a análise intraavaliadores, a identificação dos processos foi realizada por 2 avaliadores previamente treinados que avaliaram uma foto de cada participante e a análise interavaliadores for realizada por um avaliador que analisou as mesmas fotos duas vezes com 24 horas de intervalo entre as análises. Foi utilizado o coeficiente de correlação intraclasse (CCI) para análise da reprodutibilidade inter e intravaliadores e o teste proposto por Bland e Altman para análise de concordância. Os resultados demonstraram forte reprodutibilidade para os ângulos torácicos para a análise inter e intra-avaliadores (CCI=0,99 e CCI=0,90, espectivamente) com viés de 0,280 entre as sessões do avaliador 1 e 2,490 entre os dois avaliadores. Para os ângulos lombares foi demonstrado forte reprodutibilidade interavaliadores (CCI=0,99) com viés de 0,320 . No entanto, as análises intra-avaliadores demonstraram boa reprodutibilidade (CCI=0,79) com viés de 4,60 . Dessa maneira, o processo de identificação dos referenciais anatômicos na foto (digitalização) não demonstrou ser fonte de erro capaz de comprometer a avaliação postural por meio de fotogrametria.(AU)

The identification process of anatomic references in images (scanning) on the postural assessment by photogrammetry, may be mistaken and influence the measures. This present study analyzed the inter and intra examiner reproducibility on the markers positions identification in the scanning process on the postural assessment by photogrammetry. Thirty volunteers participated in the study, mean age 25 years old (SD=5.8). The vertebrae processes (C7, T12 and L5) were identified by an examiner previously trained using the palpation method; markers were attached to the participant´s skin followed by the photo section. The thoracic and lumbar angles were calculated by those markers identification on the images by SAPO software. For the intra examiner analysis, the process identification were realized by 2 examiners previously trained, who assessed a photo from each participant and the inter examiner reproducibility were realized by an examiner who analyzed the same picture twice with 24 hours interval between them. The intraclass correlation coeficient (ICC) were used to analyze the inter and intra examiner´s reproducibility and the Bland &Altman test to the concordance analyses. The results showed strong reproducibility for thoracic for intra and inter examiners analyses (ICC=0.99 e ICC=0.9, respectively) with 0.280 bias between the examiner 1 sections and 2.490 bias between both examiners. For lumbar angles, the inter examiner reproducibility were strong (ICC=0.99) with 0.320 bias. However, the intra examiner reproducibility showed good reproducibility (ICC=0.79) with 4.60 bias. The identification process of anatomic references on the image (scanning) did not show to be an error font able to influence the postural assessment by photogrammetry.(AU)