Effects of attentional focus on improving upper limb motor performance on post-stroke patients

UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE FACULDADE DE CIÊNCIAS DA SAÚDE DO TRAIRI

PROGRAMA DE PÓS-GRADUAÇÃO EM CIÊNCIAS DA REABILITAÇÃO

CAMILA LOBO DE AGUIAR GOMES

EFFECTS OF ATTENTIONAL FOCUS ON IMPROVING UPPER LIMB MOTOR PERFORMANCE ON POST-STROKE PATIENTS

SANTA CRUZ – RN 2019

UNIVERSIDADE FEDERAL DO RIO GRANDE DO NORTE FACULDADE DE CIÊNCIAS DA SAÚDE DO TRAIRI MESTRADO ACADÊMICO EM CIÊNCIAS DA REABILITAÇÃO

CAMILA LOBO DE AGUIAR GOMES

EFFECTS OF ATTENTIONAL FOCUS ON IMPROVING UPPER LIMB MOTOR PERFORMANCE ON POST-STROKE PATIENTS

Dissertação apresentada ao Programa de Pós-Graduação em Ciências da Reabilitação da Faculdade de Ciências da Saúde do Trairi da Universidade Federal do Rio Grande do Norte, como requisito parcial para a obtenção do título de Mestre em Ciências da Reabilitação. Área de concentração: Ciências da Reabilitação.

Orientador: Enio Walker Azevedo Cacho

SANTA CRUZ – RN 2019

Universidade Federal do Rio Grande do Norte - UFRN Sistema de Bibliotecas - SISBI

Catalogação de Publicação na Fonte. UFRN - Biblioteca Setorial da Faculdade de Ciências da Saúde do Trairi - FACISA

Gomes, Camila Lobo de Aguiar.

Effects of attentional focus on improving upper limb motor performance on post-stroke patients / Camila Lobo de Aguiar Gomes. - 2019.

57 f.: il.

Dissertação (Mestrado em Ciências da Reabilitação) - Universidade Federal do Rio Grande do Norte, Faculdade de Ciências da Saúde do Trairi. Santa Cruz, RN, 2019.

Orientador: Enio Walker Azevedo Cacho.

1. Acidente Vascular Cerebral - Fisioterapia - Dissertação. 2. Habilidade Motora - Dissertação. 3. Extremidade Superior -

Dissertação. I. Cacho, Enio Walker Azevedo. II. Título. RN/UF/FACISA CDU 616.831-005

CAMILA LOBO DE AGUIAR GOMES

Effects of attentional focus on improving upper limb motor performance on post-stroke patients

Dissertação apresentada ao Programa de Pós-Graduação em Ciências da Reabilitação da Faculdade de Ciências da Saúde do Trairi da Universidade Federal do Rio Grande do Norte, como requisito parcial para a obtenção do título de Mestre em Ciências da Reabilitação.

Área de concentração: Ciências da Reabilitação.

Orientador: Enio Walker Azevedo Cacho

BANCA EXAMINADORA

Presidente da banca - Prof° Dr° Enio Walker Azevedo Cacho

Examinador Interno da instituição – Profª Drª Aline Braga Galvão Silveira Fernandes

Para se ter sucesso, é necessário amar de verdade o que se faz. Caso contrário, levando em conta apenas o lado racional, você simplesmente desiste. É o que acontece

Resumo

Introdução: A reabilitação é um processo importante na recuperação da função motora

do membro superior pós-AVC. Além disso, estudos mostram que a instrução verbal do terapeuta durante o tratamento é uma estratégia eficaz neste processo. Uma maneira de o terapeuta facilitar o comando a ser transmitido ao aprendiz é usar pistas verbais para orientação. Elas são chamadas de foco de atenção: foco interno - FI (próprio corpo) e foco externo - FE (consequência do movimento no ambiente). Para isso, é necessário avaliar os movimentos de alcance e preensão destes indivíduos, esta análise pode ser realizada a partir de instrumentos clínicos convencionais ou por aparelhos de análise cinemática de alto custo. Objetivo: Verificar os efeitos dos tipos de focos de atenção no desempenho motor da extremidade superior pós-AVC por meio de instrumento de avaliação cinemática elaborado pelos autores (Temporal Data Acquisition Instrument (TDAI) como alternativa de baixo custo e simples aplicação. Métodos: Este estudo recrutou doze sujeitos, distribuídos aleatoriamente em dois grupos por sorteio simples, onde foram solicitados a realizar duas tarefas motoras com o membro afetado (16 repetições), utilizando comandos verbais orientados por um terapeuta treinado. Na primeira fase, grupo 1 recebeu comandos com FI, enquanto grupo 2 foi instruído com comandos com FE. Após uma semana, o tipo de comando foi alterado entre os grupos. Para obter as variáveis (tempo de movimento, velocidade média e número de picos de velocidade), foi utilizado um dispositivo desenvolvido pelos autores (Temporal Data Acquisition Instrument - TDAI) e software cinemático livre - CVMob versão 4.0.

Resultados: Tanto FI como FE promoveram diferenças significativas no tempo e na

velocidade do movimento, no entanto, apenas o FI forneceu resultados significativos nas duas tarefas. Discussão: Os benefícios de um foco de atenção em relação ao outro não são totalmente confirmados. No entanto, não receber nenhum tipo de orientação de atenção induz o paciente a adotar estratégias próprias, comprometendo o desempenho motor. É pertinente que, durante a reabilitação, o terapeuta esteja ciente da importância de escolher os comandos verbais que serão orientados aos pacientes. Conclusão: Ambos os focos forneceram aprimoramentos motores semelhantes e os resultados fornecem suporte para a hipótese de que os benefícios do FE são acentuados quando precedidos pelo FI.

Palavras Chave:

Abstract

Background: Rehabilitation is an important process in the recovery of upper limb

motor function after stroke. In addition, studies show that therapist verbal instruction during treatment is an effective strategy in this process. One way for the therapist to facilitate the command to be given to the learner is to use verbal cues for guidance. They are called focus of attention: internal focus - IF (own body) and external focus - EF (consequence of movement in the environment). For this, it is necessary to evaluate the reach and grasp movements of these individuals, this analysis can be performed using conventional clinical instruments or by high cost kinematic analysis devices.

Objective: To evaluate the effects of attention focus types on upper extremity motor

performance after stroke by means of a kinematic assessment instrument developed by the authors (Temporal Data Acquisition Instrument (TDAI) as a low cost alternative and simple application. Methods: This study recruited twelve subjects, randomly assigned on two groups by simple draw, where they were asked to perform two motor tasks with the affected limb (16 repetitions), using verbal commands directed by a trained therapist. In the first phase, group 1 received commands with internal focus, while group 2 was instructed with commands with external focus. After one week, the command type changed between groups. To obtain the variables (time of movement, average speed and number of speed peaks), a device developed by the authors (Temporal Data Acquisition Instrument - TDAI) and free kinematic software - CVMob version 4.0 were used. Results: Both attentional focus (internal and external focus) promoted significant differences in time and speed of movement, however, only internal focus provided significant results in both tasks. Discussion: The benefits of one focus of attention over another are not fully confirmed. However, not receiving any kind of attention guidance induces the patient to adopt their own strategies, compromising motor performance. It is pertinent that during the rehabilitation the therapist is aware of the importance of choosing the verbal commands that will be oriented to the patients.

Conclusion: Both focuses provided similar motor enhancements and the results support

the hypothesis that the benefits of external focus are enhanced when preceded by internal focus.

SUMÁRIO 1. Introdução ... 09 2. Justificativa ... 13 3. Objetivo 14 3.1. Objetivo Geral. ... 14 3.2. Objetivos Específico. ... 14 4. Artigo 1 14 Artigo 2 ... 32 5. Considerações Finais ... 55 Referências ... 56

1. INTRODUÇÃO

Acidente vascular cerebral (AVC) é uma das principais causas de incapacidade em adultos [1]. Restaurar a função motora de membro superior (MS) continua sendo um dos maiores desafios e um importante objetivo da reabilitação de sujeitos afetados pela doença [2,3]. Um indivíduo afetado pelo AVC pode apresentar déficits cognitivos, domínio de linguagem, orientação, atenção e memória; o que pode afetar na capacidade para aprender (ou reaprender) uma habilidade motora (4).

A aquisição de movimentos envolve a coordenação e o controle dos membros ou do próprio corpo em relação às restrições impostas pelo tempo - espaço no alcance da meta. Nesse processo, o aprendiz se apropria de possíveis soluções para resolver prováveis problemas na aprendizagem da atividade (5).

Estudos vêm demonstrando que a orientação do terapeuta de como a tarefa deve ser executada pode ser o diferencial para se atingir o êxito durante o processo de reabilitação (6). Assim como envolve diversos conceitos, o processo de aprendizagem motora também sofre influências variadas, que podem ser potencializadoras ou dispersoras no processo final da tarefa que se deseja obter êxito, sendo estes considerados como variáveis de aprendizado (5,7). Entre essas variáveis, estão duas formas populares de comunicar alguém de como uma tarefa deve ser executada, sendo elas a demonstração da atividade e a instrução verbal. As duas são importantes pois são variáveis que o profissional pode manipular durante toda a prática (8,9) .

A instrução verbal mostra-se como uma estratégia de instrução mais eficiente que a demonstração em alguns casos, por exemplo, em situações de aprendizagem relacionadas ao estágio de desenvolvimento motor (10). Este recurso é um importante mediador para melhorar a representação cognitiva do modelo observado e poder orientar a atenção do aprendiz aos aspectos críticos da demonstração (6). Assim, os aspectos verbais parecem desempenhar um importante papel na modelação.

Uma maneira para o profissional facilitar o comando verbal a ser passado para o aprendiz é utilizando pistas verbais para orientação, são os chamados Focos de Atenção (6). Estes consistem em frases curtas e concisas que podem direcionar a atenção da

pessoa que irá executar os movimentos, lembrando dos componentes motores essenciais para desenvolver a tarefa (5).

Focos de atenção podem ser distinguidos em dois tipos. O Foco Interno (FI) consiste quando o terapeuta direciona a atenção para uma estrutura do corpo do praticante e o seu movimento. Já o Foco Externo (FE) consiste de forma que a atenção esteja direcionada às consequências do movimento do ambiente (11).

Como exemplo, podemos citar o movimento de arremessar um dardo. Utilizando as estratégias de FI as orientações para o praticante seriam para se concentrar no movimento do braço ou no momento de abri a mão; enquanto que com o FE os comandos seriam para observar a trajetória do dardo ou no alvo que se deseja atingir (12) .

Um crescente número de estudos tem demonstrado que a eficiência no desempenho e na aprendizagem motora tem grande dependência do foco de atenção induzido pelo terapeuta/treinador (13). Alguns estudos demonstraram efeitos distintos em foco de atenção em adultos iniciantes e habilidosos (14). Em indivíduos iniciantes, o FI propiciou melhor desempenho e também melhor padrão de execução da tarefa, uma vez que o indivíduo ainda não tinha contato com a tarefa e a sua preocupação no momento é em como desempenha-la, voltando sua atenção, portanto, para o movimento do próprio corpo (15).

Entretanto, com o decorrer da aprendizagem gradativamente o aprendiz se torna mais habilidoso, voltando sua atenção para o ambiente, a fim de elaborar metas para alcançar seu objetivo, sendo o FE mais eficaz durante essa fase (12).

Achados interessantes têm se apresentado mostrando a superioridade do FE se comparado ao FI para o desempenho de habilidades motoras. Por outro lado, acredita-se que quando não se tem instrução adequada de foco de atenção específico, o aprendiz tende a utilizar mecanismos conscientes para execução da tarefa, gerando dificuldades e lentidão no processamento de informações e execução da tarefa. Ressaltando mais uma vez a importância em propiciar um direcionamento específico para obter êxito (16).

Adotar a utilização de FE tem se mostrado mais eficaz uma vez que o mesmo está associado com a menor utilização da capacidade de memória (17). Porém, apesar

de se apresentarem como maioria, não são todos os estudos que afirmam a superioridade do FE, um pequeno número de trabalhos aponta vantagens da utilização do FI (14).

Ao se tratar de pacientes pós-AVC ainda não há estudos que comprovem quais as diferenças e efeitos dos diferentes direcionamentos de foco de atenção no aprimoramento do desempenho motor. Apesar de que o FE quando comparado com o FI apresenta resultados de maior velocidade durante realização. Entretanto, é possível que em decorrência da lesão neurológica, os achados clínicos sejam diferentes quando comparados com adultos saudáveis (11).

Portanto, o objetivo desse estudo foi verificar quais os efeitos dos diferentes tipos de focos de atenção no desempenho motor das atividades de alcance e preensão em MS de pacientes pós-AVC. A necessidade surgiu uma vez que não existe um conhecimento definido na literatura de qual foco de atenção seria mais apropriado para aprimorar o desempenho motor desses pacientes. Dessa forma, pode-se oferecer uma possibilidade de aperfeiçoamento dos comandos verbais dos terapeutas durante a prática da reabilitação com esse público, colaborando, portanto, com a eficácia no contexto da reaprendizagem motora pós-AVC.

Para isso, é necessário a utilização de instrumentos que permitam a avaliação dos movimentos de alcance e preensão em MS de indivíduos pós-AVC. Os movimentos de alcance e preensão são componentes motores comumente afetados no pós-AVC [18]. A independência desses sujeitos esta diretamente relacionada com a capacidade de desempenhar essas atividades motoras com êxito, uma vez que permitem com a execução de diversas funções e atividades de vida diária, como beber, ler e escrever [19].

Em indivíduos saudáveis, para realizar essas atividades motoras, a mão e os dedos são previamente posicionados de acordo com o tamanho, a forma e a função do objeto, além disso, o sujeito também é responsável por programar e controlar a velocidade, a precisão e a força para manter o objeto na mão durante o seu transporte [20].

Portanto, os movimentos que levam a mão em direção a um alvo devem ocorrer de modo coordenado, preciso, rápido e com menor gasto energético, permitindo, desse modo, características padrões de movimentos coordenados [19,20].

Contudo, indivíduos pós-AVC desempenham movimentos de alcance e preensão mais lentos e segmentados, podendo haver associação de movimentos compensatórios de estruturas como o ombro e o tronco, ocasionando maior gasto energético [18].

Diversos instrumentos se propõem a avaliar as atividades de alcance e preensão em sujeitos pós-AVC [21]. Entretanto, ainda permanece uma lacuna entre instrumentos clínicos comuns de avaliação e análises cinemáticas detalhadas, porém de alto custo [22].

Instrumentos clínicos como a Escala de Desempenho Funcional de Fugl Meyer (FM), Box and Block Test (BBT), Action Research Arm Test (ARAT) e REACH, objetivam quantificar as alterações de movimentos por meio de análises observacionais, classificadas posteriormente em escalas ordinais ou nominais [3,18].

A avaliação do alcance e preensão por meio de testes clínicos, quando aplicados por profissionais capacitados, permite verificar propriedades psicométricas e seus efeitos em atividades do cotidiano, apresentando o tempo de completar uma tarefa ou apresentam uma categorização do desempenho motor [22].

No entanto, os resultados desses instrumentos no que diz respeito ao controle e a mensuração de medidas, resultam em dados poucos detalhados e sujeitos a viés de observador, ocasionando resultados imprecisos e subjetivos, não só para a distinção de diferentes padrões de comprometimento, mas também para análise do seguimento do tratamento dessas atividades motoras [18,23,24,25].

Entretanto, as análises laboratoriais cinemáticas permitem analisar de forma precisa e detalhada os pontos que necessitam serem abordados a fim de promover o aprimoramento dos movimentos de alcance e preensão, além de serem análises facilmente reprodutíveis, promovendo resultados consistentes [18,23,26].

Os dados cinemáticos também são usados para fornecer feedback audiovisual em tempo real ao participante para autoavaliação do movimento. As interações envolvem-se para motivar a conclusão da tarefa e promover o aprendizado generalizado dos elementos motores relacionados à tarefa [25].

Contudo, muitos desses instrumentos para avaliação cinemática se limitam a utilização somente laboratorial, por necessitarem de ambientes controlados e

personalizados, além de sua utilização complexa e alto custo para aquisição e alta demanda de tempo para montagem e calibração [27,28,29].

Diante disso, existe a necessidade de dispositivos que possam complementar os resultados oferecidos pelos instrumentos clínicos de avaliação, a partir de dados cinemáticos detalhados e precisos, que apresentem baixo custo para aquisição e facilidades para ajustes e calibração, além de possibilitar avaliação fora do ambiente laboratorial.

2. JUSTIFICATIVA

Visando apresentar uma solução acessível e de simples manuseio, o objetivo deste estudo foi apresentar uma possibilidade de avaliação cinemática dos movimentos de alcance e preensão em MS de indivíduos pós-AVC, por meio de um equipamento elaborado e construído por fisioterapeutas em parceria com uma equipe coordenada por um engenheiro eletricista (Artigo 2).

Além disso, a partir da construção deste equipamento, é possível a utilização do mesmo na investigação de outros aspectos, como verificar quais os efeitos de cada um dos focos de atenção (atenção para o próprio corpo – Foco Interno - ou atenção direcionada para o ambiente - Foco externo) no desempenho motor de hemiparéticos, comparando qual direcionamento irá proporcionar melhores resultados durante a execução dos movimentos de alcance e preensão, uma vez que não existe conhecimento definido na literatura de qual foco de atenção é mais apropriado para obter melhores resultados em pacientes pós-AVC (Artigo 1).

Dessa forma, podendo contribuir com as avaliações desses importantes aspectos temporais nos ambientes clínicos, como também no engajamento de pesquisas científicas a respeito do tema a partir de dados precisos obtidos por meio de um equipamento de baixo custo, além da possibilidade de investigar os efeitos da

orientação do terapeuta do desempenho motor de indivíduos pós-AVC, podendo oferecer possibilidade de aprimoramento no comando verbal do terapeuta durante a prática da reabilitação.

3. OBJETIVOS 3.1. Objetivo Geral

Confeccionar um equipamento de baixo custo, capaz de avaliar dados temporais a respeito dos movimentos de alcance e preensão em indivíduos pós-AVC; (Artigo 2)

Utilizar o equipamento para observar aspectos cinemáticos na execução dos movimentos de alcance e preensão a partir de diferentes direcionamentos de atenção induzidos a indivíduos pós-AVC. (Artigo 1)

3.2. Objetivos Específicos

Proporcionar dados complementares às informações obtidas por meio de instrumentos clínicos, podendo ser utilizadas por terapeutas e pesquisadores, não só no ambiente laboratorial, como também clínico;

Descrever o desempenho motor dos indivíduos, perante ao comandos verbais, a partir da análise oferecida por meio do instrumento elaborado;

Correlacionar os resultados obtidos por meio dos instrumentos clínicos convencionais com os dados do TDAI;

4. ARTIGOS 4.1. Artigo 1

Effects of attentional focus on improving upper limb motor performance on post- stroke patients

Camila L. A. Gomes1*, Roberta O. Cacho2, Viviane T. B. Nobrega1, Fabio Galvão1, Ellen Marjorie de A. Confessor3, Eyshila Emanuelle M. de Farias4, José Leôncio F. Neto4, Denise S. de Araújo5, Ana Loyse de S. Medeiros5, Emanoelle C. V. Silva5, Rodrigo L. Barreto6, Enio W. A. Cacho7.

Abstract

Background: Rehabilitation is an important process in the recovery of upper limb

motor function after stroke. In addition, studies have shown that therapist verbal instruction during treatment is an effective strategy in this process. One way for the therapist to facilitate the command to be passed to the learner is by using verbal cues for guidance. They are called focus of attention: internal focus -IF (own body) and external focus –EF (consequence of movement in the environment). Objective: To verify the effects of focus types on post-stroke upper extremity motor performance. Methods: This study recruited twelve subjects randomized into two groups by simple draw. The groups were asked to perform two motor tasks with the paretic limb (16 repetitions), using verbal commands directed by a trained therapist. In the first phase, G1 received commands with IF, while G2 was instructed with commands with EF. After one week, the command type was changed between groups. To obtain the variables (movement time, average velocity and number of speed peaks), a device developed by the authors (Temporal Data Acquisition Instrument - TDAI) and free kinematic software - CVMob version 4.0 was used. Results: Both EF and IF promote significant differences in movement time and speed, however, only IF provided significant results in both tasks.

Discussion: The benefits of one focus of attention on the other are not fully confirmed.

However, not receiving any kind of attention guidance induces the patient to adopt their own strategies, compromising motor performance. It is pertinent that during the rehabilitation the therapist is aware of the importance of choosing the verbal commands that will be oriented Conclusion: Both focus provided similar motor enhancements and the results provides some support for the hypothesis that the benefits of the EF are accentuated when preceded by the IF.

Trial Registration: Trial Registration: Research Ethics Committee of the Trairi School of Health Sciences - Number 2.625.609, approved on April 13, 2018; Brazilian Registry of Clinical Trials - RBR-4995cr approved on July 4, 2019 retrospectively registered (http://www.ensaiosclinicos.gov.br/rg/RBR-4995cr/ )

Keywords: Stroke, Physical Therapy, Upper Extremity, Motor Skill Background

The performance of motor activities performed by the upper extremity (UE) is commonly affected in post-stroke patients, where slower, segmented movements and often associated with compensatory movements, causing higher energy expenditure [1].

Rehabilitation therapies are the basis of the treatment to facilitate the motor function recovery and the integration into society after stroke [2]. This process suffers several influences, which may be potentiating or dispersing in the final process of the task to be successful, being considered as learning variables [3].

Studies have shown that therapist/coach guidance on how the task should be performed is a central and effective strategy in the rehabilitation process [4,5,6]. This resource is an important mediator to promote the cognitive representation of the observed model and to guide the learner's attention to the critical aspects of movement. Thus, verbal commands seem to be an important role in motor learning, increasing the perception of success during practice [4,5,7].

One way for the therapist/coach to facilitate the command to the learner is by using verbal cues for guidance: short, concise sentences that can direct the attention of the person performing the movements, remembering the essential motor components to perform the task [3].

Attentional focus can be distinguished into two types. The first, Internal Focus (IF), when the practitioner's attention is directed to the body structure and its movement, not related to the environment [8]. As an example we can cite a skill such as javelin throwing, where information would be related to the arm movement or the moment of opening hand to release javelin [4,9,10]. Another type is External Focus (EF), when the information provided is directed to the consequences of environmental movement, in which case the attentional focus would correspond to the trajectory of the javelin or the target [4,8,11,12].

A growing number of studies have shown that efficiency in motor learning and performance is highly dependent on attentional focus induced by the therapist/coach [3,4,11,13,14]. Some studies have shown the superiority of EF compared to IF for performance and learning of motor skills [4,6,11,15,16]. Meanwhile, when there is no adequate instruction of specific attention focus, the learner/patient tends to use conscious mechanisms for task execution, generating difficulties and slow information processing and task execution [4,6,8,17].

This advantage presented by the use of EF commands with healthy individuals can be considered since findings concluded that it is responsible for promoting consistent improvements in the results of movement effects (such as accuracy and reduction of reaction time), allowing automated motor control, while IF promotes more conscious movement [4,8,16].

However, it is not clear the benefits of each type of focus of attention in post- stroke individuals, as also the relationship between the level of motor impairment or the memory as factors that may influence the use of focus [9]. Normally, patients are often given complex and large instructions, which can be confusing, even more because they are people who may have some attention and memory impairment, slowing down the processing speed of this information and consequently in the motor learning [18].

Therefore, aiming at the need for studies that address the theme, the objective of this study was to verify the effects of different types of focus of attention on the motor performance of UE in post-stroke patients. The requirement emerge since there is no defined knowledge in the literature of which focus of attention would be the most appropriate to improve the motor performance of these patients. Thus, it may be possible to improve therapists´ verbal commands during rehabilitation with these patients, since communication during therapy can have a great impact on patients' performance and on the motor learning. Contributing, therefore, to the effectiveness in the context of post-stroke motor relearning.

Methods Participants

It is an experimental study of quantitative nature. This study recruited 12 individuals admitted to the Integrated Clinic of the Trairi School of Health Sciences

(Facisa - UFRN), located in Santa Cruz - Rio Grande do Norte - Brazil, from January to April 2019. The study was approved by the local ethics committee (Opinion 2.625.609) and Brazilian Registry of Clinical Trials (RBR 4995CR).

Patients should: I) be able to perform flexor / extensor synergy movements related to subsection 3 of the Fugl Meyer Upper Extremity Assessment (FMA-UE), with a score between 1 and 2; II) have no sensory alteration in UE assessed by Nottingham Scale; III) have no presence of cognitive impairment assessed by the Mini Mental State Examination - MMSE (cutoff: 20 points for illiterate; 25 to 28 for educated individuals – [19]); IV) HAVE a single unilateral stroke; V) should be over 18 years old.

These clinical instruments (FMA-UE, Nottingham Scale and MMSE) were used for prior evaluation and to characterize the sample and inspect the inclusion and the exclusion criteria (40 minutes for the test).

Intervention

The 12 selected individuals were randomly into two groups by simple draw to minimize bias (Group 1 - G1 and Group 2 - G2). After this division, individuals from both groups were asked to perform two motor tasks with the paretic UE, 16 repetitions, oriented by verbal commands guided by a trained therapist. In a first phase (phase A), lasting approximately 30 to 40 minutes, G1 received commands with IF, while G2 was instructed with commands with EF.

After one week, in phase B, the type of focus of attention was switched between groups. That is, G1 received FE and G2 was instructed with IF. The second phase (phase B) was implemented in order to verify if the order of receipt of the verbal

command types promotes influence on the UE motor performance after stroke (G1 - FI followed by FE; G2-FE followed by FI).

Regardless of phase and group, individuals always performed the same tasks, changing only the type of verbal command. In this study, two UE motor skills were used: reach-pointing (task 1 - T1), where participants should reach and touch three targets arranged in an “L” shape; and reach-hold-fit (task 2 - T2), in which individuals should carry a glass between two distinct targets, spaced 15 cm apart. Sixteen repetitions of each task were performed, with an interval of 15 seconds between each repetition and three minutes between each type of task.

The clinical protocol of both tasks was performed with the patient sitting, with the back supported and the trunk without restrictions, facing a table with adjustable height, and the elbow positioned at 90 ° of flexion, the shoulder at 0 ° and the hand on the table (demarcated point).

In front of the individual, the equipment (Temporal Data Acquisition Instrument - TDAI, built by the authors) was positioned at a distance equivalent to 90% of the arm length (distance measured between the axillary line and the sternum styloid process).The TDAI, when positioned vertically, offered the three targets T1, where the participant must reach and touch the targets in the specified order (See Fig. 1).

Figure 1. Participant positioning. The execution of both tasks was performed with the

individual in the same position, the only changes were made only on the platform, where for task 1 it was placed vertically (left image), while for task 2 the platform remained horizontally, the circumferences were arranged - these being the targets of the task in question - and the cup positioned above the platform (right image).

For T2, the equipment was positioned horizontally, and two circumferences spaced 15 cm in a straight line made up the new targets. This time, the individual should reach a cup that is set to the farthest target, grab it, carry it and fit it to the nearest target. Each target in both tasks consisted of capacitive sensors coupled to the data acquisition board.

Before starting each task, the therapist demonstrated only once the movement that would be performed. Then the subject was asked to make one movement attempt. This moment corresponded only for observation, where the professional verified the strategies used by the participant to reach the targets and the motor points that needed the guidance. Then, to perform the 16 repetitions, a simple verbal command (according to the group and phase) was directed to the patient. The list of verbal commands used for each type of attention focus is shown in Table 1 and their construction was based on the protocol of previous study [9].

Table 1. Internal and External commands

Desired body movement Internal Focus External Focus Trunk - extension Try to stretch your arm instead of

pushing your trunk forward

Try to get as close as possible to the target by keeping against the chair Shoulder – flexion Raise your arm higher Go towards the target

Shoulder – extension Try to keep your elbow close to your body.

See this sticker on the table? Try to follow it

Elbow – extension Stretch your elbow more Get closer to the target Wrist As you move your arm forward, try

to bend your hand

As you get close to the target, try to bring that target toward

Fingers – task 1 Look at your fingers, straighten your index finger

Touch targets in number order Fingers – task 2 (to

open)

Look at your fingers, push them apart

Try to open as time as you encompass the glass Fingers – task 2 (to

close)

Bend all fingers, closing your hand Encompass the glass fuly to make more secure

Thumb Spread your thumb away from the rest of your fingers

See this tape? Take the sticker closer to you (blue sticker placed on the subject's thumb before the protocol begins)

Grasping Close your hand, bringing your fingers firmly together.

Grab the glass and take it toward the ceiling away from the table. Fitting Bring it closer to your body and

snap it

Bring the glass closer to the table to fit the target

Velocity This time, try moving your arm faster

This time try to touch the targets / grab the glass faster

Coordination As you stretch your arm open your hand. Try to make both movements

together.

As you approach the target, prepare to grab the glass.

Each repetition was preceded by a single simple verbal command (only in the last five repetitions could be used combined commands with a maximum of two commands for repetition) and by sound trigger (from the data acquisition board), transmitted by the evaluator as a reference to the participant to initiate the movement.

To obtain the variables, in addition to the TDAI, a free cinematic software - CVMob version 4.0 - was also used, and the whole experiment was filmed using a Canon Vixia R800 FullHd camera with a sampling frequency of 30Hz (image consent form was signed by the participants). For this, reflective markers (1 cm in diameter) were used at the upper extremities (acromial process, lateral epicondyle, styloid ulnar).

The camera was positioned in the sagittal plane. Thus, data processing (using the TDAI and CVMob files) was performed using Octave in version 4.2.1 to calculate as variables: movement execution time (including time to reach each goal and total time), average speed and number of speed peaks.

Statistical analysis

BioEstat version 5.3 was used for data analysis. Data normality was assessed by the Shapiro-Wilk test and nonparametric tests were adopted. The study population and clinical characteristics were defined using descriptive statistics. Friedman's test

compared all 16 repetitions of each task, in each phase, to determine the change in motor performance.

Mann Whitney test was used for intergroup comparison and determination of differences between the IF and the EF (G1 Phase A - Internal Focus x G2 Phase A - External Focus; G1 Phase B - External Focus x G2 Phase B - Internal Focus). For this, the averages of the first three repetitions (initial averages) and the average of the last three repetitions (final averages) of each task were used.

The Wilcoxon test was used to compare the intragroup and establish whether the order in which different types of attention are given to practitioners interferes with motor performance (G1 Phase A x G1 Phase B; G2 Phase A x G2 Phase B, using the first three repetitions and the last three repetitions of each task).

Results

Data related to sample characterization are show in Table 2.

Table 2. Demographics and Clinical Characteristics of Participants (n = 12)

Characteristic G1 (n=6) G2 (n=6) Sex, n (%) Female Male 2 (33.4) 4 (66.6) 2 (33.4) 4 (66.6) Age, in years Median (1Q/3Q) 64 (52.2/70.2) 66 (62.5/72.5) Scholarity, n (%) Schooled Illiterate 3 (50) 3 (50) 5 (83.4) 1 (16.6) Time onset stroke, in years

Median (1Q/3Q) 6 (3.5/8.5) 3 (3/4.5) Paretic hand, n (%) Right Left 2 (33.4) 4 (66.6) 4 (66.6) 2 (33.4) FMA-UE Median (1Q/3Q) 54.5 (49.5/55.7) 53(49/54.7)

Nottingham Sensorial Test

Median (1Q/3Q) 152 (143.7/153) 143.5 (137.5/148)

MMSE

n, number; 1Q, first quarter; 3Q, third quarter; FMA-UE, Fugl Meyer Assessment for the Upper Extremity; MMSE, Mini-Mental Status Examination.

All subjects were ischemic stroke. All subjects were right-handed.

To analyze the motor behavior (total time, velocity and speed peaks) in each group over the 16 repetitions (R), the Friedman test was used (Figure 2). In Phase A - task 1, statistically significant differences were found between the first repetitions and from repetition nine (9R), in the total time and mean velocity variables, in both groups.

In Phase A - task 2, in relation to G1 (IF), was observed significance in the variable total time (seconds - s), between 1R (Median: 2.62s - Quartiles: 2.32 / 3.31)) and 7R (2.15s; 2.06 / 2.52) to 10R (2.14s - 1.87 / 2.91), as well as 12R (2.05s - 1.94 / 3.28), 14R (2.05s - 1.97 / 2.82) and 16R (1.96s; 1.59 / 2.75). In addition to significant differences between 8R (2.06s - 1.79 / 2.78) and 16R, compared with 2R (2.52s - 2.32 / 2.66) and 3R (2.40s - 2.08 / 2.66). In relation to the mean velocity variable, a significant difference was also observed between 10R (1.0cm/s 0.94 / 1.26) and 15R (1.15cm/s -1.00 / 1.43) when compared to 1R (0.06cm/s - 0.04 / 0.08). We did not find significant differences in the peak speed variable in the two tasks in G1 phase A.

Figure 2. Motor behavior along the 16 repetitions of Phase A. The two images above

represent the variables of total time (in seconds), average velocity (in centimeters per second) and the number of peaks of velocity for group 1 - phase A (with attention focused to internal focus), where in both tasks were observed significant values in total time and average velocity. In the two lower images are represented the temporal variables of group 2 - phase A (external focus), which in turn presented significant values only in task 1.

Motor behavior along the 16 repetitions of Phase B - task 1 was also analyzed by Friedman test (Figure 3). In Phase B – task 1, statistically significant differences were found between the first repetition (1R) and the ninth repetition (9R), in the total time and number of peaks of velocity in G1 (EF). While in G2 (IF), only total time had significant differences since 9R. In Phase B – task 2 no significant differences were found, in both groups.

Figure 3. Motor behavior along the 16 repetitions, in both tasks, of Phase B. The two

images above represent the temporal for group 1 - phase B (external focus). In this phase, the variables of total time number of peaks of velocity presented significant values (task 1). In the two lower images are represented group 2 – phase B (internal focus), that only total time had significant values, also in task 1. Task 2, in both groups, did not show significant changes in motor behavior during repetitions.

The data related to intergroup analyzes, obtained through the Mann Whitney Test, as well as intragroup, through the Wilcoxon Test. For this, the averages of the first three repetitions (initial averages) and the average of the last three repetitions (final averages) of each task were used (Table 5). No statistically significant differences were found between the final intergroup averages and both phases.

Table 5. Intragroup analysis and intergroup during Task 1, in both phases. Phase A

Internal Focus (G1) External Focus (G2)

Initial Averages Final Averages Initial Averages Final Averages

Total Time (s) 3.8 (3.1/4.2)a 3.1 (2.3/3.7)b 3.7 (3.3/4.2)a 3.2 (2.7/3.4)

Mean Velocity (cm/s) 0.87 (0.84/0.99)a 1.2 (1.1/1.4)b 0.8 (0.6/1.3) 1.6 (1.0/1.9)

Peak of Velocity (n) 6.5 (5.2/7.7)e 4.5 (4.0/8.0) 7.5 (6.2/8.7)e 5.5 (2.7/6.0) Phase B

Initial Averages Final Averages Initial Averages Final Averages

Total Time (s) 3.3 (3.0/3.5)c,f 3.0 (2.7/3.1) 4.2 (3.5/4.9)c,f 3.9 (3.0/4.7)

Mean Velocity (cm/s) 1.6 (1.3/1.6) 1.5 (1.2/1.7) 1.5 (0.4/1.8) 1.9 (0.9/1.7)

Peak of Velocity (n) 6.0 (6.0/6.0)f 5.0 (5.0/6.5) 6.0 (4.2/7.0)f 5.5 (5.0/6.0)d

Values in: median (first quartile / third quartile)

G1 = Group 1; G2 = Group 2; Q= quarter; s = seconds; cm/s= centimeters per seconds; n= number

a _{significant difference between initial average (phase A) x final average (phase A);} b _{significant difference between}

final average (phase A) x initial average (phase B); c significant difference between initial average (phase B) x final average (phase B); d significant difference between final average (phase B) x inicial average (phase A); e significant difference between G1 (phase A) Initial Averages x G2 (phase A) Initial Averages; f significant difference between G1 (phase B) Initial Averages x G2 (phase B) Initial Averages;

Discussion

Therapists often invest considerable talk time during rehabilitation, where instruction and feedback are constantly being given. It is therefore necessary for the therapist to consider important to recognize that the focus of attention (coming from communicating with the learners / practitioners during therapy) have an important impact on the performance and on the motor learning of their patients [14]. Besides that is a variable of the motor learning process that the therapist can regulate and manipulate throughout the treatment, and may potentiate the desired results.

It is possible that post-stroke individuals respond differently to the types of focus of attention in relation to the healthy individuals, since the theme still has a limited number of studies related to its effects on these individuals, besides being a broadly heterogeneous group, which may allow different types of responses depending on the individual's level of commitment [9,14,20,21,22].

However, not receiving any kind of attention guidance, either IF or EF, induces the patient to adopting their own strategies, generating greater attention / memory demand, compromising the automated motor [8]. This statement can be observed in this study, since both types of focus allowed significant positive changes in the execution

time and in the mean velocity aspects when comparing the first repetitions with the final repetitions.

Studies state that healthy individuals who receive attention focus for EF tend to focus on the task's end goal, promoting shorter motor reaction and control times, while those receiving IF related instructions focus on the movement of the body and in how to consciously control it, which can lead to superficial muscle activity and impairing task performance [4,8,11,12,16,22].

Adopting EF has been associated with less memory processing, where post- stroke individuals may benefit [21,23,24]. However, a study with a small sample (n = 10) showed that the use of IF has superiority with respect to the execution of dynamic balance activities [18].

Few studies have investigated the effects of directing attention on post-stroke individuals and most of them explore exclusively at its immediate effects on the motor performance [9,25,26]. In this study, the immediate effects of the different types of focus of attention were also investigated. Motor performance measures were observed in three different ways: first, over 16 repetitions of two tasks, where the changes in each group were analyzed differently.

For this first analysis, it was observed, as already mentioned, that both EF and IF promoted significant differences in time of execution and in the mean velocity. However, it can be observed that verbal commands with attention directed to IF promoted a greater amount of significant alterations in the mentioned variables, being observed in both tasks, while in the EF results were found only in task 1.

At first, it is not clear in the literature the benefits of one focus of attention on the other, even not the relationship between the level of the motor impairment or of the memory as factors that may influence the use of the type of focus [9,22].

To try to investigate what differences may exist between the types of focus and their effects on post-stroke motor performance, we performed a second analysis, which observed the motor behavior from intergroup comparison, where this time comparison was made between groups, in the both phases (G1 - Phase A (IF) was compared with G2 - Phase A (EF), later G1 - Phase B (EF) in relation to G2 - Phase B (IF)) and no significant value was found between the means of the final repetitions between the groups that received the IF or the EF in both phases. These results coincide with previous studies, where both focus of attention provided similar improvements [22,27]. Observational studies suggest that post-stroke patients during rehabilitation should first receive attention from IF [9,14,25].

In addition, post stroke individuals tend to instinctively use IF to control movement over the years [28]. This fact may compromise the automation of movement in these individuals, a phenomenon called “constrained action hypothesis” [4,9,26].

Given this, we performed a third analysis to verify if the order of receipt of verbal commands (IF followed by EF (G1) or EF then IF (G2)) would provide statistically significant values in the aspect of motor performance. The results suggest that the benefits of EF are accentuated when preceded by IF, since G1 (IF followed by EF) had significant values in the total time and mean velocity variables, while G2 (EF followed by IF) presented only in the matter of time.

This outcome corroborates previous studies and may suggest that during clinical practice it is interesting to provide patients with information about their own movement

first, to guide them in the following sessions about the effect of movement on the environment, thus improving the motor performance of individuals [9].

Conclusion

Both focus of attention provided similar motor enhancements, offering positive effects on total time of execution and mean velocity variables, where the only difference found from one type of focus to another was that the focus of attention to IF provided significant differences in both selected tasks, while EF only in the first task.

In addition, the results provide support for the hypothesis of better use of verbal guidance, provided by the therapist on the post-stroke, when commands directed to EF are preceded by IF. It is pertinent that the therapist during rehabilitation is aware of the importance of verbal commands during therapy, since it is a motor learning variable that can be easily manipulated by the therapist to obtain the expected results; observing the particularities of each individual in order to use verbal instructions that are concise and simple to understand and yet significant for improving the post-stroke motor performance.

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4.2. Artigo 2

Low Cost Equipment for the Evaluation of Reach and Grasp in Post-Stroke Individuals: A Pilot Study

Camila L. A. Gomes1*, Roberta O. Cacho2, Viviane T. B. Nobrega1, Ellen Marjorie de A. Confessor3, Eyshila Emanuelle M. de Farias4, José Leôncio F. Neto4, Denise S. de Araújo5, Ana Loyse de S. Medeiros5, Rodrigo L. Barreto6, Enio W. A. Cacho2.

Abstract

Background: Reach-grasp movements are motor components commonly affected after stroke and directly related to the independence of these individuals. Evaluations of these activities can be performed using clinical instruments and assessed by detailed and costly kinematic analyses. The aim of this study was to develop an analysis of reach- grasp movements in post-stroke patients using a simple, inexpensive, and manageable instrument. Results: A Mann-Whitney test was used to compare paretic and non paretic limb motor performance. A statistically significant difference was found between the variables of total time (p = 0.02) and speed to reach target 3 (p = 0.04) for task 1, while in task 2 significance was found only in the aspect of speed to reach target 2 (p = 0.04). The correlation between clinical tests and variables of tasks was then performed using Spearman´s rank correlation coefficient. At task 1, when compared with the REACH instrument, the close target sub-item, there was a high positive correlation between the parameters of total time (p = 0.028), target velocity 3 (p = 0.028), and target acceleration 3 (p = 0.028). Another instrument that showed a high positive correlation with the target time 3 (p = 0.01) and target acceleration 3 (p = 0.028) variables was the Box and Block Test. When correlated, the data between the task 2 variables and clinical instruments did not present statistically significant data. Conclusion: Our instrument - the Temporal Data Acquisition Instrument – TDAI - fulfilled the expected objectives and can be used as an option to evaluate the movements of reach and grasp of upper limb post-stroke, using an easy and fast application, without the need for calibration. Trial Registration: Trial Registration: Research Ethics Committee of the Trairi School of Health Sciences - Number 2.625.609, approved on April 13, 2018; Brazilian Registry of Clinical Trials - RBR-4995cr approved on July 4, 2019 retrospectively registered (http://www.ensaiosclinicos.gov.br/rg/RBR-4995cr/ )

Keywords: Stroke, Physical Therapy, Upper Extremity, Hand Strength, Equipment Failure Analysis.

* Author Correspondence: camilalobofisio@gmail.com Full address

Full list of author information is available at the end of the article.

The functional independence of individuals after stroke is directly influenced by the ability to perform reaching and grasping movements successfully [1]. However, the performance of these motor activities is commonly affected after stroke, leading to slower and segmented movements, and these, in turn, may be associated with compensatory movements of structures such as the shoulder and trunk [2].

Reach and grasp movements involve the coordination of the fingers and thumb, previously positioned according to the size, shape, and function of the object that are combined with the movement of the arm towards the object and the control of the force to hold the target and keep it in the hand during its transport [1,3].

Several conventional and standardized clinical measures aim to verify reach and grip activities in post-stroke subjects [4]. Instruments, such as the Fugl Meyer Functional Performance Scale (FM), Box and Blocks Test (BBT), and Action Research Arm Test (ARAT), aim to quantify movement changes through observational analyses, further classified on either ordinal or nominal scales [2,5].

The assessment of reach and grasp through clinical tests, when applied by trained professionals, allows the verification of psychometric properties and their effects on daily activities. In addition, the evaluation uses instruments that are inexpensive, simple, and quick to apply [6]. However, the results of these instruments have a gap for control and measurement of procedures to provide more meaningful and detailed results, not only for distinguishing different patterns of impairment and compensation strategies but also for analyzing follow-up during treatment of these motor activities [2,7].

Kinematic laboratory analyses allow the objective and precise examination of the points that need to be addressed to improve reach and grasp movements [7,8].

However, these instruments for kinematic assessment are still under development, and many of the available and consolidated products are costly [9,10].

For this reason, because of the scarcity of free or low-cost equipment, it is necessary to improve studies involving the construction of devices that allow evaluations of different parameters of reach and grasp movements using conventional clinical instruments for clinical and scientific purposes.

Therefore, the aim of this study was to develop an inexpensive, manageable tool for assessing reach-grasp movements that enables the analysis of aspects not addressed by conventional clinical measures and provides an alternative to expensive kinematic analysis equipment.

Methods

The Temporal Data Acquisition Instrument (TDAI) system was designed by the authors and provide an automated interface with data acquisition, capture, and processing data of human movement variables (movement times, mean velocity, mean acceleration, and movement effectiveness) from the upper limb extremity (UE) using two motor skills (reach-point - T1 and reach-grasp-fit - T2). The TDAI system was built to be used easily by the therapist in a clinical setting, has a low-cost of installation and maintenance (was designed and built with investment less than $25), and is capable of producing kinematic information on reaching, grasping, and pointing movements.

Equipment design

The TDAI allows the assessment of reach-grasp and pointing movements by two tasks. In T1 (reach-point), the participant must reach and touch three targets arranged in an “L” shape. While in T2 (reach-grasp-fit), the individual must carry a glass between two distinct targets spaced 15 cm apart.

The material is composed of a single board, rectangular (28.19 cm in length, 20.35 cm in width, and 5 mm in depth). At the anterior part, the targets that must be reached in each activity are indicated: three targets arranged in an “L” shape (T1) and two distinct circumference of 5 cm in diameter (T2).

The back part of the board is used for positioning capacitive sensors by snapping them into hollow parts (rectangles measuring 14.7 mm x 11 mm x 4 mm), in reference to targets positioned on the front of the plate (see Fig. 1). However, as the entire back part of the board is made up of hollow rectangles, it is possible that the capacitive sensors are positioned not only according to the tasks determined by the authors, but also to use the arrangement that is desired.

The TDAI has two structures that allow its positioning on the table according to the activity. It can remain vertically (T1) or be placed horizontally (T2). The main board and its accessories (cylinders and bracket) were constructed of poly-plastic (PL) filaments.

Figure 1. Front and back of the board. TDAI consists of a single plate, that can be positioned

vertically (T1) or horizontally (T2). On the front of the board (part “a”) the targets of each activity are indicated (targets represented by “x” –T1; items “A” and “B” –T2). The back of the board (part ‘b”) is intended for fitting the capacitive sensors, referring to the selected targets on the front of the board. Targets related to task 1 were represented by numbers to indicate the sequence to be followed, as well as by rectangles of different colors (part "c"). The targets of task 2 consisted of two circles, where the cup was to be transported from the farthest target and fitted to the nearest target (part "d").

The equipment contains a circuit referring to capacitive sensors, components used for the acquisition of time data. They are inserted into the rectangular cavities, positioned according to the activity to be performed. The capacitive touch sensor (11 mm width x 14.5 mm length x 2.3 mm height) was used to replace the direct button switch to ensure user accessibility.

Sensor input voltages range from 2 V-5.5 V DC. The Touch TTP-223 module has a maximum response time of 60 milliseconds after incitation. This component is responsible for identifying the individual's touch and sending the electrical impulses from the incitement to the ATmega328 microcontroller that processes the information with a 16 MHz clock, which ensures system reliability (See Fig 2).

Figure 2. Signal conditioning circuit of the sensor. Sensor input voltages range from 2 V-5.5

V DC. The touch module TTP-223 processes the information with a 16 MHz clock, being sensitized ≤60 miliseconds after contact. The 22 pF capacitor adjusts sensor sensitivity, 100 nF and 100 uF capacitors stabilize input voltages, eliminating high- and low-frequency noise. Communication with the computer is UART, using the I2C protocol.

Evaluation by the TDAI System

The assessment using the TDAI consists of a single session protocol, lasting 20- 30 minutes, where two reaching and grasping activities are performed with the affected UE. The clinical protocol was performed with the patient sitting, with the back supported and the trunk free (without restrictions), facing a table with adjustable height,

and the elbow positioned at 90° of flexion, the shoulder at 0° and the hand on the table at a demarcated point (Figure 3).

Figure 3. Participant positioning for TDAI assessment. To perform both tasks the individual

is positioned in the same way, and the adjustments are made only on the platform, where for task 1 it is placed vertically (left image), while for task 2 the platform remains horizontal (right image).

Before the start of each task, simple verbal instructions and a demonstration were passed to the evaluated patients. Sixteen repetitions of each task were performed for each upper limb, with an interval of 15 seconds between each repetition and 3 minutes between each type of task. Each repetition was preceded by a sound trigger (from data acquisition plate), issued by the evaluator, as a reference to the participant to start the movement with his usual velocity.

For T1 (reach-point), the equipment is vertically fitted to the table, away from the margin equivalent to 90% of arm’s length - the distance measured between the axillary line and the styloid process of the radius from the sternum. Capacitive sensors are positioned so that the targets are in the shape of the letter “L,” where the distance

between the first and second target is 15 cm (from its center) and 8 cm between the second and third targets.

For the accomplishment of T2 (reach-grasp-fit), the subject remains in the same position. However, modifications are made to the equipment: the capacitive sensors are repositioned so that they are straight and spaced at 15 cm. The main board is fitted to the table horizontally, and two cylinders (6 cm in diameter) are fitted into the front of the plate, in the same direction as the sensors, forming two different targets - where the farthest remains at 90% of arm's length from the table edge. After the firing sound, the subject should reach for a glass (5 cm in diameter, 8 cm high), fitted to the farthest target, hold it, carry it, and fit it to the nearest target. At the end of each repetition, the patient returns to the starting point, and the instructor returns the cup to target 1.

Clinical outcome measures

The TDAI processes information about the time to reach each target (seconds), total activity time (seconds), mean speed (cm/s), mean acceleration (cm/s2), and effectiveness (number of hits). These functions are performed on a practical, fast, economical, and manageable piece of equipment that does not require calibration or maintenance.

The variables are found using simple equations and by performing the routine to obtain the data in the spreadsheet software. The values for movement time are divided into the total time and times to reach targets 1, 2, and 3 (T1) and times to reach targets 1 and 2 (T2).

In Eq. 1, ∆t is the time value to be found, where to refers to the time of the beep and t to the time the target has been reached. Therefore, this equation is used in three moments for T1 (target time 1, target 2, and target 3, where the latter also corresponds to the total time) and in two moments for T2 (target times 1 and 2, the latter also being equivalent to the total time).

Data related to the average velocity were obtained using Eq. 2.

(Eq.2)

Where ∆d refers to the straight line distance from the table and target mark 1 (of the task in question), and ∆t corresponds to the time variation. This result is used to obtain the mean acceleration values, according to Eq. 3.

(

)

In Eq. 3, ∆V refers to speed variation, while t refers to time variation. Efficacy values are obtained as a percentage, where 100% is 16 hits (all repetitions).

Experimental protocol

The experimental protocol was carried out at Trairi Health Sciences Faculty (Facisa - UFRN), located in Santa Cruz - Rio Grande do Norte–Brazil. Eight patients with a clinical diagnosis of stroke, who were capable of performing flexor/extensor synergy movements related to the Fugl Meyer Assessment for Upper Limb Extremity (FMA-UE) with a score between 1 and 2, had an absence of sensory alteration in UE evaluated by the Nottingham Scale, or the presence of cognitive impairment assessed by the Mini-Mental Status Examination - MMSE (cutoff: 20 points for illiterate; 25 to 28 for schooled [11]). All patients experienced a single unilateral stroke and should be over 18 years old.

A prior clinical evaluation (FMA-UE, Nottingham Scale, and MMSE) was performed to characterize the sample and inspect the inclusion and exclusion criteria and lasted 40 minutes. Subsequently, a trained therapist used specific clinical instruments (REACH Performance Scale, BBT, and ARAT) intended for the analysis of reach and grip movements (30 minutes for testing). The Reach Scale (REACH) focuses on compensatory strategies that are used during the transport phase in the range of motion and is defined by the beginning of the movement until the object is reached.

The test is divided into two sub-items, which are the near target (1 cm from the table’s edge) and distant target (30 cm from the table’s edge) [12]. Each subcategory evaluates six components: trunk dislocation, movement fluidity, shoulder movements, elbow movements, and grip. Each component ranges from 0 to 3 (where zero indicates maximum compensation and three is equivalent to normal movement), corresponding to a maximum score of 18 points [12].

The BBT consists of a manual dexterity test where a wooden box is used, divided in half in two parts by a partition higher than the edges of the box. Evaluation occurs by the number of wooden cubes (2.5 cm) carried from side to side of the box for one minute. The test is performed primarily with the unaffected limb, followed by the compromised limb [13].

Finally, the ARAT, also known as the Upper Limb Extremity Action Test, has 19 items that evaluate complex grip-related UE activities. The score ranges from 0 (no movement can be performed) to 57 (indicating normal motor performance). This scale does not allow classifying subjects as normal, mild, or severely limited [14].