The relationship between internal and external loads as a tool to monitor physical fitness status of team sport athletes: a systematic review

The efficiency index (Effindex) combines internal and external loads, and it has been considered a promising tool to evaluate physical fitness status. However, its real applicability and limitations have not been elucidated yet. To examine and discuss the findings from studies that used Effindex as a tool for the evaluation of physical fitness status in team sports. A systematic search was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). The databases conferred were PubMed, Scopus, Web of Science, SPORTDiscus, MEDLINE and CINAHL. The articles selected were published up to March 2021. Fourteen articles were included after meeting the inclusion criteria. A wide variety of combinations of external and internal loading parameters to calculate Effindex were found. The pooled sample included 349 male participants (23 ± 3years). Fifty-nine percent of the sample were soccer players, 20% rugby players, 10% Australian football players, 7% hurling players, and 4% basketball players. Most Effindex calculations used total distance (TD) divided by heart rate derived parameters. However, recent studies have suggested the use of accelerations as the external load parameter. Effindex is a simple and powerful tool for the evaluation of physical fitness status in team sports athletes. The disparity of external and internal loading parameters used to calculate Effindex may affect its sensitivity to detect changes in fitness status in different team sport settings. More studies with indoor team sports and female athletes are warranted

Comparação da destreza manual em indivíduos com lateralidade distinta

INTRODUÇÃO: A destreza manual pode ser definida como a habilidade e a facilidade na utilização das mãos, como escrever, dedilhar um instrumento musical, lançar e apanhar. A lateralidade pode ser conceituada como a preferência de utilização por um dos membros em detrimento ao outro e se confirma, por exemplo, em indivíduos destros e canhotos, influenciando nos distintos desempenhos das mãos. OBJETIVO: Comparar a destreza manual em destros e canhotos através da tarefa de colocar e retirar pinos no Grooved Pegboard Test.  MÉTODOS: A amostra foi composta por 20 voluntários saudáveis, de ambos os sexos, com idade entre 18 e 40 anos, dividida em dois grupos, sendo:  5 homens e 5 mulheres de população destra e 5 homens e 5 mulheres de população canhota. Referente ao índice de dominância lateral, os indivíduos destros apresentaram índice médio de 97% e os indivíduos canhotos de 91% no Inventário de Dominância Lateral de Edimburgo. RESULTADOS: Na condição de colocar os pinos foram observadas diferenças entre as mãos dos destros [t(df=9)=-7,16; p=0,01] e dos canhotos [t(df=9)=4,80; p=0,01], o uso da mão preferida apresentou melhor desempenho relacionado ao uso da mão não preferida. Já para a condição de retirar os pinos não foram observadas diferenças entre as mãos direita e esquerda para os destros [t(df=9)=-1,96; p=0,08] e nem para os canhotos [t(df=9)=1,27; p=0,23]. Em relação ao índice de assimetria não foram observadas diferenças entre os grupos, apesar de parecer que as assimetrias se destacam em tarefas nas quais a demanda cognitiva é maior do que a demanda energética. CONCLUSÃO: O desempenho nas tarefas de destreza manual foi diferente para a mão preferida tanto para destros quanto para canhotos, sendo que a mão preferida apresentou melhor desempenho quando comparada à mão não preferida.Comparison of manual dexterity in individuals with distinct lateralityABSTRACT BACKGROUND: A manual dexterity can be defined as the skill and ease of using the hands, such as writing, strumming a musical instrument, throwing and catching. Laterality can be conceptualized as the preference of use by one of the members over the other and it is confirmed, for example, in right-handed and left-handed individuals, influencing the different performances of the hands. OBJECTIVE: To compare manual dexterity in right-handed and left-handed users by placing and removing pins in the Grooved Pegboard Test. METHODS: The sample consisted of 20 healthy volunteers, of both sexes, aged between 18 and 40 years, divided into two groups: 5 men and 5 women from the right population and 5 men and 5 women from the population left-handed. Regarding the lateral dominance index, right-handed individuals had an average index of 97% and left-handed individuals, 91%, in the Edinburgh Lateral Dominance Inventory.  RESULTS: In the condition of placing the pins, differences were observed between the right-handed [t(df=9)=-7.16; p=0.01] and left-handed [t(df =9)=4.80; p=0.01], where the use of the preferred hand showed better performance related to the use of the non-preferred hand. As for the condition of removing the pins, no difference was observed between the right and left hands for the right-handed [t(df=9)=-1.96; p=0.08] and neither for the left-handed [t(df=9)=1.27; p=0.23]. Regarding the asymmetry index, no differences were observed between the groups, although it seems that the asymmetries stand out in tasks where the cognitive demand is greater than the energy demand. CONCLUSION: The performance in the tasks of manual dexterity was different for the preferred hand for both right-handed and left-handed people, with the preferred hand presenting a better performance when compared to the non-preferred hand

Eccentric strength assessment of hamstring muscles with new technologies: a systematic review of current methods and clinical implications

Background: Given the severe economic and performance implications of hamstring injuries, there are different attempts to identify their risk factors for subsequently developing injury prevention strategies to reduce the risk of these injuries. One of the strategies reported in the scientific literature is the application of interventions with eccentric exercises. To verify the effectiveness of these interventions, different eccentric strength measurements have been used with low-cost devices as alternatives to the widespread used isokinetic dynamometers and the technically limited handheld dynamometers. Therefore, the purpose of the present systematic review was to summarize the findings of the scientific literature related to the evaluation of eccentric strength of hamstring muscles with these new technologies. Methods: Systematic searches through the PubMed, Scopus, and Web of Science databases, from inception up to April 2020, were conducted for peer reviewed articles written in English, reporting eccentric strength of hamstrings assessed by devices, different to isokinetic and handheld dynamometers, in athletes. Results: Seventeen studies were finally included in the review with 4 different devices used and 18 parameters identified. The pooled sample consisted of 2893 participants (97% male and 3% female: 22 ± 4 years). The parameters most used were peak force (highest and average), peak torque (average and highest), and between-limb imbalance (left-to-right limb ratio). There is inconsistency regarding the association between eccentric hamstrings strength and both injury risk and athletic performance. There is no standardized definition or standardization of the calculation of the used parameters. Conclusions: The current evidence is insufficient to recommend a practical guide for sports professionals to use these new technologies in their daily routine, due to the need for standardized definitions and calculations. Furthermore, more studies with female athletes are warranted. Despite these limitations, the eccentric strength of hamstring muscles assessed by different devices may be recommended for monitoring the neuromuscular status of athletes

Eccentric Strength Assessment of Hamstring Muscles with New Technologies: a Systematic Review of Current Methods and Clinical Implications

[EN] Background: Given the severe economic and performance implications of hamstring injuries, there are different attempts to identify their risk factors for subsequently developing injury prevention strategies to reduce the risk of these injuries. One of the strategies reported in the scientific literature is the application of interventions with eccentric exercises. To verify the effectiveness of these interventions, different eccentric strength measurements have been used with low-cost devices as alternatives to the widespread used isokinetic dynamometers and the technically limited handheld dynamometers. Therefore, the purpose of the present systematic review was to summarize the findings of the scientific literature related to the evaluation of eccentric strength of hamstring muscles with these new technologies. Methods: Systematic searches through the PubMed, Scopus, and Web of Science databases, from inception up to April 2020, were conducted for peer reviewed articles written in English, reporting eccentric strength of hamstrings assessed by devices, different to isokinetic and handheld dynamometers, in athletes. Results: Seventeen studies were finally included in the review with 4 different devices used and 18 parameters identified. The pooled sample consisted of 2893 participants (97% male and 3% female: 22 ± 4 years). The parameters most used were peak force (highest and average), peak torque (average and highest), and between- limb imbalance (left-to-right limb ratio). There is inconsistency regarding the association between eccentric hamstrings strength and both injury risk and athletic performance. There is no standardized definition or standardization of the calculation of the used parameters. Conclusions: The current evidence is insufficient to recommend a practical guide for sports professionals to use these new technologies in their daily routine, due to the need for standardized definitions and calculations. Furthermore, more studies with female athletes are warranted. Despite these limitations, the eccentric strength of hamstring muscles assessed by different devices may be recommended for monitoring the neuromuscular status of athlete

Efeitos do nível de estabilização do desempenho e estruturação da prática na adaptação a pertubações visuais imprevisíveis

Submitted by Maria Gomes ([email protected]) on 2019-10-25T19:30:28Z No. of bitstreams: 1 Crislaine Rangel Couto - Tese doutorado.pdf: 4325831 bytes, checksum: 76c6e921ebf121e292339c3e20bcc64b (MD5)Approved for entry into archive by Eliane Andrade ([email protected]) on 2019-10-31T12:00:40Z (GMT) No. of bitstreams: 1 Crislaine Rangel Couto - Tese doutorado.pdf: 4325831 bytes, checksum: 76c6e921ebf121e292339c3e20bcc64b (MD5)Made available in DSpace on 2019-10-31T13:04:35Z (GMT). No. of bitstreams: 1 Crislaine Rangel Couto - Tese doutorado.pdf: 4325831 bytes, checksum: 76c6e921ebf121e292339c3e20bcc64b (MD5) Previous issue date: 2018-05-25A adaptação motora frente a perturbações imprevisíveis depende da competência dos modelos internos atualizarem o comando motor em curso, através do mecanismo de controle via feedback. O tipo de prática interfere nas características dos modelos internos formados e, consequentemente, na adaptação motora, que é melhor quando são formados módulos experts, especializados para uma ação específica. A prática que vai além da estabilização do desempenho e também a prática aleatória favorecem a formação de modelos internos competentes para se adaptar. Entretanto, não foram encontrados estudos que investigaram a interação entre o nível de estabilização do desempenho e a estruturação da prática na adaptação a perturbações visuais imprevisíveis. O objetivo desta tese foi investigar os efeitos da interação entre nível de estabilização do desempenho e estruturação da prática na adaptação a perturbações visuais imprevisíveis. Dois experimentos foram realizados, ambos compostos por duas fases: Pré-exposição e Exposição. No experimento I, na Pré-exposição os participantes foram divididos em quatro grupos que combinaram as variáveis nível de estabilização e organização da prática: estabilização-aleatória, estabilização-constante, especialização-aleatória e especialização-constante. No experimento II, os participantes alcançaram a estabilização do desempenho, mas foram divididos em dois grupos com duas formas de prática combinada: aleatória-constante e constante-aleatória. A tarefa consistia em interceptar um alvo móvel e virtual utilizando um efetor. Em ambos os experimentos, o nível de estabilização do desempenho foi manipulado com o alcance de critérios específicos de desempenho. A organização da prática foi manipulada pela velocidade de deslocamento do alvo. Vinte quatro horas após a fase de Pré-exposição teve início a fase de Exposição, na qual todos os grupos realizaram 129 tentativas, sendo 99 tentativas-controle e 30 com perturbações. As perturbações foram inseridas de forma imprevisível e consistiram em uma modificação na velocidade de deslocamento do alvo após o início da ação. A modificação foi caracterizada pelo aumento e redução da velocidade em relação às tentativas-controle. Em conjunto, os resultados dos dois experimentos demonstraram que o desempenho de todos os grupos melhorou ao longo da fase de Pré-exposição, com o mecanismo de controle sendo predominantemente via feedback. A fase de Exposição testou a competência dos modelos internos formados durante a primeira fase, quando foi necessário enfrentar as perturbações. No geral, os resultados do experimento I demonstraram que o grupo estabilização-aleatória foi o que teve mais dificuldade para lidar com as perturbações, sendo que os demais grupos apresentaram competências similares. Já os resultados do experimento II demonstraram que o grupo aleatório-constante apresentou maior dificuldade para lidar com as perturbações, quando comparado ao grupo constante-aleatório. Em ambos os experimentos, todos os grupos utilizaram predominantemente o mecanismo de controle via feedback. Estas diferenças apontam para os efeitos da interação entre as variáveis manipuladas na competência dos modelos internos em se adaptar a perturbações visuais imprevisíveis.The motor adaptation to unpredictable perturbations depends on internal models’ capacity to actualize the ongoing motor command through the control mechanism via feedback. The type of practice influences the characteristics of the formed internal models’ and, consequently, motor adaptation, which is better when expert models are formed and specialized to a specific action. The practice beyond performance stabilization and also random practice improves the competence to adapt of the formed internal models. However, no studies investigating the interaction between the level of performance stabilization and practice schedule on adaptation to unpredictable visual perturbation was found. The aim of this thesis was to investigate the interaction effects of the level of performance stabilization and practice schedule on adaptation to unpredictable visual perturbation. Two experiments were run, both composed by two phases: Pre-exposure and Exposure. On experiment I, during Pre-exposure the participants were divided in four groups combining the level of stabilization and practice schedule variables: stabilization-random, stabilization-constant, specialization-random, specialization-constant. On experiment II, the participant reached the performance specialization, but they were divided in two groups of combined practice: random-constant and constant-random. The task consisted of intercept a virtual moving target using an effector. During both experiments, the level of performance stabilization the level of performance stabilization was manipulated with specific criterion of performance. The practice schedule was manipulated through the velocity of target displacement. Twenty-four hours after Preexposure phase started the Exposure phase, when all the groups performed 129 trials, with 99 control trials and 30 perturbation trials. The perturbations were inserted in a unpredictable way and consisted of changing the velocity of target displacement after the onset of the action. The modification was characterized by the velocity increment or decrement when compared to control trials. Summarizing, the results of both experiments showed that performance of all groups increased throughout Pre-exposure phase, and the control predominant mechanism via feedback. The exposure phase tested the competence of the internal models formed during the first phase, when was necessary facing perturbations. In general, the results from experiment I showed that the stabilization-random group was the one which more difficulty to deal with the perturbations, and all the other groups had similar competence. The results from experiment II showed that the group random-constant had more difficulty to deal with perturbations, compared to constant-random group. On both experiments, all groups used predominantly the mechanism control via feedback. These differences point to the interaction effects between the manipulated variables on the internal models competence to adapt to unpredictable visual perturbations

EFEITOS DA PRÁTICA DO JUDÔ NA COORDENAÇÃO MOTORA DE CRIANÇAS E ADOLESCENTES AUTISTAS

The aim of the present study was to investigate the effects of judo practice on the motor coordination of autistic children and adolescents. The sample consisted of 10 children and adolescents from six to 14 years old, autistic, male, being: five judo practitioners and school physical education classes (GJ) and five practitioners of school physical education classes (GC). All participants were students from public institutions (one school and one clinic) in the city of Belo Horizonte. To participate in the research, prior authorization from the parents was required. The evaluation of the coordinating capacities took place from the application of the Körperkoordinationstest Für Kinder (KTK). The performance presented in the subtests and the global motor quotients (QM) were analyzed. Student t test for independent samples was used to compare the groups. The results showed superiority of the GJ over the CG in the dynamic balance and monopedal jump sub tests. Regarding the QM, it was found that the GJ presented a classification of disturbance in coordination. The CG was classified as having insufficient coordination. Together, our results show that although no group has satisfactory levels of coordination, the GJ performed better than the CG, which points to the beneficial effects of the practice of judo in the coordination of autistic children and adolescents.   Received on: 2020/08/14 Reformulated on: 2021/01/14 Accepted: 2021/01/14O objetivo do presente estudo foi investigar os efeitos da prática do judô na coordenação motora de crianças e adolescentes autistas. A amostra foi composta por 10 crianças e adolescentes de seis a 14 anos de idade, autistas, do sexo masculino, sendo: cinco praticantes de judô e de aulas de educação física escolar (GJ) e cinco praticantes de aulas de educação física escolar (GC). Todos os participantes eram alunos de instituições públicas (uma escola e uma clínica) do município de Belo Horizonte. Para a participação na pesquisa, foi necessária a autorização prévia dos responsáveis. A avaliação das capacidades coordenativas se deu a partir da aplicação do Körperkoordinationstest Für Kinder (KTK). Foi analisado o desempenho apresentado nos subtestes e o quociente motor global (QM). Para comparação entre os grupos foi utilizado o teste t de Student para amostras independentes. Os resultados mostraram superioridade do GJ em relação ao GC nos subtestes de equilíbrio dinâmico e salto monopedal. Em relação ao QM foi encontrado que o GJ apresentou classificação de perturbação na coordenação. Já o GC foi classificado com insuficiência na coordenação. Em conjunto, nossos resultados mostram que apesar de nenhum grupo apresentar níveis satisfatórios de coordenação, o GJ apresentou desempenho superior ao GC, o que aponta para os efeitos benéficos da prática do judô na coordenação de crianças e adolescentes autistas. Recebido em: 14/08/2020 Reformulado em: 14/01/2021 Aceito em: 14/01/202

Jiu Jitsu as a treatment tool for children with Autism Spectrum Disorder

The objective of this study was to verify the effects of a jiu jitsu program on the motor performance and functional skills (self-care and social function) of children with ASD. The sample was composed by six children, being three of the control group and three of the experimental group, with ages between 6 and 12 years old submitted to Jiu Jitsu practice. The intervention had the duration of one year and three months (80 sessions) and were used the Test of Gross Motor Development-2, and Pediatric Evalution of Disability Inventory. The results point significant improvement of experimental group, after the Jiu Jitsu intervention, in manipulative performance, selfcare, social function and also less help from the parents for the task realization. It's possible to conclude that this modality may be an instrument for ASD treatment and can contribute to the planning of interventions and assist coaches and health professionals.O objetivo deste estudo foi verificar os efeitos de um programa de jiu jitsu no desempenho motor e nas habilidades funcionais (autocuidado e função social) de crianças com TEA. A amostra constituiu de seis crianças, três do grupo controle e três do grupo experimental com idades entre 6 e 12 anos submetidas à prática do jiu jitsu. A intervenção teve duração de um ano e três meses (80 sessões). Os instrumentos utilizados foram o Test of Gross Motor Development-2, e o Pediatric Evalution of Disability Inventory. Os resultados apontam melhoras significativas do grupo experimental após a intervenção no desempenho manipulativo, no autocuidado, na função social, e menor ajuda dos pais para a realização das tarefas. É possível concluir que o jiu jitsu representa um instrumento de tratamento para o TEA contribuindo para o planejamento das intervenções e auxiliando os treinadores e os profissionais da saúde

RAZMERJE MED ZMOGLJIVOSTJO V MOČI IN GIBALNO ZMOGLJIVOSTJO V STOJI NA ROKAH: MODEL STROJNEGA UČENJA

The present study investigated the relationship between strength capacity and motor performance in the gymnastic handstand. The hypothesis stipulated a positive relationship between motor performance and strength capacity levels. Thirty-two university students, 16 female and 16 male (24.03 ± 4.74 years of age,) participated in the study. The handstand was assessed using the absolute error of the three angles produced by the model (video) and the three angles produced by the performer. We conducted four strength tests: explosive force, maximum right-hand grip strength, maximum left-hand grip strength, and resistance force. The machine learning model was trained using 10 of the folds and cross-validated, and a linear regression test was performed using motor performance (absolute error) and strength tests (explosive force, maximum force right-hand, maximum force left-hand, and resistance force). The results showed that the machine learning model indicated a low relationship between strength capacity and motor performance. Additionally, motor performance was not found to be related to strength capacity. The results may indicate that specific capacities and the interaction of factors such as task specificity, environment, and individual characteristics influence motor performance.Raziskava je preučevala razmerje med zmogljivostjo moči in gibalno zmogljivostjo v stoji na rokah. Hipoteza je določala pozitivno razmerje med gibalno zmogljivostjo in stopnjami moči. V raziskavi je sodelovalo 32 študentov, 16 študentk in 16 moških (24,03 ± 4,74 let). Stoja na rokah je bila ocenjena s popolno napako treh kotov, ki jih je ustvaril model (video) in treh kotov, ki jih je ustvaril izvajalec. Izvedli so štiri teste moči: eksplozivna sila, največja moč desnega prijema, največja moč levega prijema in sila upora. Model strojnega učenja je vadil z uporabo 10 poskusov in je navzkrižno veljaven, izveden pa je bil tudi linearna regresija z gibalno zmogljivostjo (nesporna napaka) in meritvami moči (eksplozivna sila, največja sila na desni strani, največja sila na levi strani in sila upora). Rezultati so pokazali, da je model strojnega učenja pokazal nizko razmerje med zmogljivostjo moči in gibalno zmogljivostjo. Poleg tega ni bilo ugotovljeno, ali je gibalna zmogljivost povezana z močjo. Rezultati lahko kažejo, da določene zmogljivosti in sodelovanje dejavnikov, kot so posebnost naloge, okolje in posameznikove lastnosti, vplivajo na gibalno zmogljivost

The level of performance stabilization influences motor adaptation on an isometric force control task

<div><p>This study compared the effects of two levels of performance stabilization on the adaptation to unpredictable perturbations in an isometric control force task with the goal of controlling 40% of the maximum force. The experiment consisted of pre-exposure and exposure phases. In the pre-exposure two levels of performance stabilization were manipulated: a stabilization group (SG) performed three trials in a row while maintaining 40% of the maximum force for three seconds and an absolute error less than or equal to 5% (i.e., the criteria of performance), and a superstabilization group (SSG) performed six blocks of the same criteria. During the exposure phase, the task was the same as that in the pre-exposure phase; however, it was inserted 9 trials of perturbations when the task goal changed to 60% of the maximum force. We measured the %RMSE, RMS from the biceps and triceps brachii and co-contraction. In the pre-exposure phase, both groups showed similar performance and muscle activity. When exposed to the perturbations, SSG performance more quickly returned to the previous level of accuracy, showed lower muscle activation and demonstrated a greater muscle co-contraction than did SG. The results give support to the adaptive process model on motor learning.</p></div

Measures from SG and SSG in the pre-exposure phase.

<p>a) Mean of root mean square error (RMSE%); b) (RMS) of biceps; c) (RMS) of triceps; d) Co-contraction.</p