Swimmers' Effective Actions during the Backstroke Start Technique.

The analysis of the external forces of swimming starts has revealed how swimmers propel themselves out of the block, but data should be properly interpreted to fully understand force-generation mechanisms. This study aimed to assess horizontal and vertical forces in the backstroke start based on swimmers' structural and propulsive actions. Firstly, a simulated structural force was estimated by two transient backstroke-start inter-segmental realistic body positions: a maximally tucked position and an extended one (just before the hands-off and the take-off, respectively). Secondly, 10 competitive backstroke swimmers performed four 15 m maximal backstroke starts with the external forces estimated. Thirdly, the simulated structural force was subtracted from raw horizontal and vertical force data, measured between hands-off and take-off instants, resulting in the propulsive forces. The application of the algorithm has evidenced that backstrokers' horizontal and vertical simulated-structural-force components contributed to ~40% of total force during start propulsion (~0.2-0.12 s before the take-off), followed by the propulsive horizontal force increment and a progressive vertical component reduction (~0.05 s) with ~20° take-off angle. Based on these findings, researchers and coaches can better guide swimmers as to the proper mechanical strategies to achieve effectiveness in the backstroke start, and to improve direct transfer of resistance training programs.

Effect of land- and aquatic-based plyometrics on spike and block reaches in young volleyball players: a pilot study

Abstract Aim: The purpose of this pilot study was to analyze the feasibility of the intervention and measures of a six-week land- and aquatic-based plyometric training on spike and block reaches in young volleyball athletes. Methods: Twelve female players were divided into a land group (LG) (n = 6, 12.4 ± 0.3 years, 1.61 ± 0.04 m, 57.0 ± 9.3 kg) and a water group (WG) (n = 6, 12.5 ± 0.5 years, 1.57 ± 0.06 m, 48.9 ± 8.5 kg). The spike and block (without step, with slide step, and with crossover step) reach and countermovement jump height were evaluated before and after a 6-week plyometric training protocol. Duration (total and of each session), adhesion and adherence, and safeness of the intervention; completion of assessments, within-trial reliability, and variability of the outcome measures and preliminary results were the variables of interest. To analyze the effect of the training on jump performance, the Wilcoxon test was used (p < 0.05), and effect sizes (r) were calculated. Results: All participants concluded the intervention and the assessments as planned. No dropouts or adverse events were registered during the study. The within-trial reliability for all assessment tests was considered excellent (ICC ≥ 0.9). Preliminary results indicate that LG improved the reach of the spike and block with the slide step; and that WG improved the spike, block with the slide step to the left, and block without movement reaches (p < 0.05; large effect size). Conclusion: An intervention of six weeks of plyometric training on land and in water is feasible, and preliminary results indicate that both training protocols may benefit the performance of spike and block in young volleyball athletes.

Factors associated with injuries in Hawaiian canoe paddlers / Fatores associados a lesões em remadores de canoa havaiana

Abstract Introduction The Hawaiian canoe has numerous bene-fits for those who use it. Furthermore, it is considered a moderate/high-intensity cyclic sport that can cause injuries. Studies on factors associated with injuries in Hawaiian canoe paddlers are considered limited and scarce. Objective To identify the profile of canoe paddlers and determine the main factors associated with injuries. Methods A cross-sectional study was conducted with 100 Hawaiian canoe paddlers (54% females, 45.6 ± 10.0 years old; 46% males, 44.8 ± 11.7 years old) using an online survey, with questions on sociodemographic and anthropometric information and practice and injuries. Results Participants reported having at least four years of experience with the modality, training approximately four times a week for a total of six hours. Almost half (45%) of the sample reported having been injured at least once while canoeing. The back/spine was the body region with the highest injury prevalence, with 38.6%. Intense training was considered the only associated factor for injuries (odds ratio: 3.98; 95% confidence interval: 1.71 - 9.26). Conclusion This pioneering study in Brazil allowed us to profile Hawaiian canoe paddlers and identify the main factors associated with injuries. Paddlers who train intensely are more likely to develop injuries during practice. Therefore, this variable must be considered when planning sessions.

Resumo Introdução A canoagem havaiana apresenta inúmeros benefícios para os praticantes. Apesar disso, é uma prática considerada com gestos cíclicos, realizada com intensidade moderada/intensa e que pode ocasionar lesões. As evidências sobre os fatores associados às lesões em remadores de canoa havaiana são consideradas limitadas e escassas. Objetivo Identificar o perfil dos remadores brasileiros de canoa havaiana e verificar os fatores associados às lesões. Métodos Trata-se de um estudo transversal conduzido em 100 remadores de canoa havaiana (54% sexo feminino, 46,2 ± 8,5 anos; 46% do sexo masculino, 44,8 ± 11,7 anos) por meio de uma pesquisa online. O instrumento utilizado continha perguntas sobre as variáveis sociodemográ-ficas, antropométricas, prática da modalidade e lesões. Resultados Os participantes reportaram ter experiência de pelo menos quatro anos com a modalidade, treinando aproximadamente quatro vezes por semana e totalizando seis horas de treino semanal. Quarenta e cinco por cento da amostra relatou ter sido lesionada pelo menos uma vez durante a prática da modalidade. As costas/coluna foi a região corporal com maior prevalência de lesão, com 38,6%. Treinos intensos foram considerados os únicos fatores associados para lesões (razão de chance: 3,98; intervalo de confiança: 1,71 - 9,26). Conclusão Este estudo pioneiro no Brasil permitiu traçar o perfil dos remadores de canoa havaiana, bem como identificar os principais fatores associados a lesões. Remadores que treinam intensamente estão mais propensos a desenvolver lesões durante a prática, portanto, esta variável deve ser levada em consideração no planejamento das sessões.

The Effect of Aquatic Plyometric Training on Jump Performance Including a Four-week Follow-up in Youth Female Volleyball Players.

This study aimed to analyze the effect of aquatic plyometric training (APT) on jump performance in volleyball players. Twelve female athletes (16.6 ± 0.9 years) were assessed through the following jump tests: spike height (SH), squat jump (SJ), countermovement jump (CMJ) and CMJ with an arm swing (CMJA). Jump height in each test and the eccentric utilization ratio (EUR) were the outcome measures. APT consisted of sets of drop jumps for 6 weeks (2 sessions/week) at a water depth of 0.75 m. Tests were performed at the beginning of a five-week pre-season period, before and after APT, and four weeks later for the follow-up. Repeated measures ANOVAs were used to analyze data and Hedges' g to estimate effect size (ES). Performance of all jumps did not change from baseline to Pre-APT. Performance improved in SH (p < 0.001, ES: 1.09), the SJ (p = 0.045, ES: 0.76) and the CMJA (p < 0.001, ES: 0.78) after APT when compared to Pre-APT. No changes were observed after the follow-up period. In conclusion, including six weeks of APT in the training routine of youth volleyball players improved performance of a sport-specific task (SH), the SJ and CMJA, with gains preserved after a four-week follow-up.

Activation of the gluteus maximus, gluteus medius and tensor fascia lata muscles during hip internal and external rotation exercises at three hip flexion postures.

BACKGROUND: Hip internal and external rotation exercises are usually performed in clinical practice. However, given the synergies required to stabilize the hip in the frontal plane, it is not clear how the activation of target muscles will differ between the two exercise directions. OBJECTIVE: I) Compare the activation of the upper and lower fibers of gluteus maximus (GMax), gluteus medius (GMed) and tensor fascia lata muscles between the hip internal and external rotation exercises; ii) Compare the maximal isometric force between hip internal and external rotation exercises and; iii) Assess the effect of varying hip flexion angles on muscle activation and maximal isometric force. STUDY DESIGN: A cross sectional study. METHODS: Electromyography and force production of twenty-one participants were measured during maximum isometric hip internal and external rotation in three postures: 0°, 45° and 90° of hip flexion. RESULTS: MANOVA results showed a larger activation of the GMed, tensor fascia lata and upper GMax (p < .001) for hip internal rotation compared to external rotation regardless of hip flexion angle. For the lower GMax, the same was observed when the hip was kept at 90° of flexion. Maximal isometric force during hip external rotation was greater than during hip internal rotation at 0° posture, and lower at 90° posture (p < .001). CONCLUSION: The gluteus and the tensor fascia lata muscles were substantially recruited during the hip internal rotation exercise, and barely recruited during the hip external rotation exercise. Hip flexion influences the myoeletric activity and isometric force production during the internal rotation exercise.

Reliability of impulse oscillometry parameters in healthy children and in children with cystic fibrosis.

INTRODUCTION & AIMS: Impulse oscillometry system (IOS) is an instrument developed to evaluate the mechanical lung properties. It has been reported that to analyse the exam in a proper way it is necessary to carry out more than one measure. However, studies addressing the standardisation are still scarce. The objective was to determine within trial reliability of three measures in IOS parameters in healthy children and children with cystic fibrosis (CF). METHOD: Weight, height, body mass index, forced spirometric and the oscillometric parameters (resistance, respiratory impedance, respiratory reactance and resonance frequency) data were collected, in a way that all participants performed three IOS measures. To evaluate, the reproducibility was used the intraclass correlation coefficient [two-way mixed model, absolute agreement definition, ICC]. The response stability was appraised using the standard error of measurements (SEM) in three repetitions of the IOS in the healthy children group (HCG) and in the cystic fibrosis group (CFG). RESULTS: About 95 subjects participated, in each group with a mean age of 10.89 ± 2.21 years old in the HCG and 9.73 ± 2.43 years old in the CFG, having been 41 and 43 boys and 54 and 52 girls, in the respectively group. In both groups, all IOS parameters evaluated in the three measures presented an ICC of 0.9, which is a high reproducibility. CONCLUSION: The IOS parameters are reproducible for healthy children and CF children in three measures. However, according to the population studied, the performance of only one measure is sufficient to assess respiratory mechanics, whereas the SEM were low, except for Fres, in both groups.

Isokinetic hip muscle strength: a systematic review of normative data.

The aim of this study was to conduct a systematic review to determine the quality of evidence of studies assessing isokinetic hip muscle strength in adult non-injured individuals. We also aimed to summarise and pool data of normative values for hip muscle strength. The influence of methodological and participant-related factors on hip strength performance was explored as well. Guidelines proposed in the PRISMA were used to undertake a search strategy involving the keyword 'hip' associated with a set of keywords reflecting muscle strength. Five databases were searched: ProQuest, PubMed, Science Direct, Scopus and Web of Science. From the 2,939 records initially retained, 28 articles were included in this systematic review. Eight articles were classified as high quality. This systematic review exposed the methodological fragility of most studies assessing hip strength in non-injured adult population. Only data from studies with a small number of participants are available to be used as reference. A few individual studies suggest no differences in torque parameters between dominant and non-dominant lower limbs; differences in torque parameters between age groups; and between male and female participants. Overall, reference values for hip muscle performance in isokinetic tests are mostly unclear.

Aerials and their influence on World Surfing League surfer performance (WSL flights) / Os aéreos e sua influência no desempenho dos surfistas da Liga Mundial de Surf (Aéreos WSL)

Abstract This research aimed to verify whether the number of airplanes run by surfers in the 2016 Word Surf League (WSL) men's season and their grades were related to their final classification in the events and season. Were viewed 3475 waves from 49 surfers and selected for analysis 275 waves. Spearman's correlation test, one-way ANOVA, and t-test, with p?0.05, were used for statistical analysis. The air proved to be an effective maneuver in isolated clashes, helped to reach the finals and decide events, but did not prove to be the main determinant of the season's final standings. The average of the marks attributed to the reverse 360 ??aerial was significantly higher than the notes attributed to the reverse aerial, however, the variables the position of the surfer in front or back to wave and whether or not to grab the board edge did not present significant differences.

Resumo Esta pesquisa teve como objetivo verificar se a quantidade de aéreos executados pelos surfistas na temporada masculina da Word Surf League (WSL) de 2016 e suas respectivas notas tiveram relação com a classificação final deles nos eventos e na temporada. Foram visualizadas 3475 ondas de 49 surfistas e selecionadas para analise 275 ondas. Utilizou-se o teste de correlação de Spearman, ANOVA um fator e o teste t, com p?0.05, para análise estatística. O aéreo se mostrou uma manobra eficaz em confrontos isolados, ajudou a chegar às finais e a decidir eventos, mas não se mostrou ser o principal determinante para a classificação final da temporada. A média das notas atribuídas ao aéreo reverse 360 foi significativamente maior que as notas atribuídas ao aéreo reverse, no entanto, as variáveis posições do surfista de frente ou de costas para onda e agarrar ou não borda da prancha, não apresentaram diferenças significativas.

Trunk muscular endurance, lumbar spine mobility and hip flexibility in sailors with and without low back pain / Análise da resistência muscular do tronco, mobilidade da coluna lombar e flexibilidade do quadril em velejadores com e sem dor lombar

Abstract Introduction: Low back pain is one of the most common injuries in sailors. Findings in the literature indicate that poor trunk endurance, flexibility and muscle strength are common in individuals with low back pain (LBP). Objective: Analyze trunk muscle endurance, lumbar spine mobility and hip flexibility in windsurfers with and without low back pain. Method: Sailors of both sexes with at least three years' experience in the sport answered the Nordic Musculoskeletal Questionnaire and were submitted to Schober's test, the passive straight leg raise (PSLR), the modified Thomas test, and isometric endurance assessment of the flexor, extensor and lateral flexor muscles of the torso. The sailors were divided into two groups (with and without LBP) and compared using the Student's t-test or Mann Whitney U test. Results: Participants were 22 national-level sailors, 11 with low back pain (LBP) and 11 without (NLBP). The LBP group obtained longer holding times for the trunk extensors (p=0.028) and a greater difference in endurance between the right and left sides for lateral trunk muscles (p=0.030). Both groups obtained results below normative values in most of the tests performed. Conclusion: Sailors with low back pain exhibited greater trunk extensor endurance and a larger imbalance between lateral trunk muscles when compared to those with no LBP. Spinal mobility and hip flexibility were similar between groups.

Resumo Introdução: A dor lombar é uma das lesões que mais afeta os velejadores. Achados na literatura mostram que a deficiência de força do tronco, flexibilidade e resistência muscular é comum em indivíduos com dor lombar. Objetivo: Analisar a resistência muscular do tronco, a mobilidade da coluna lombar e a flexibilidade do quadril em velejadores com e sem dor lombar. Método: Velejadores de ambos os sexos e com no mínimo três anos de prática responderam ao questionário nórdico de lesões osteomusculares e realizaram os testes de Schöber, de Elevação Passiva da Perna Estendida, de Thomas Modificado e de resistência isométrica dos músculos flexores, extensores e laterais do tronco. Os velejadores foram divididos em dois grupos (com e sem dor lombar), comparados por meio do teste t de Student para amostras independentes ou U de Mann Whitney. Resultados: 22 velejadores de nível nacional, 11 com dor lombar (CDL) e 11 sem dor lombar (SDL), participaram do estudo. O grupo CDL apresentou maior tempo de permanência no teste de resistência dos extensores do tronco (p=0,028) e maior diferença entre os lados direito e esquerdo no teste de resistência dos músculos laterais do tronco (p=0,030). Na maioria dos testes realizados, os dois grupos apresentaram resultados abaixo dos valores normativos. Conclusão: Velejadores com dor lombar apresentaram maior resistência dos extensores do tronco, porém maior desequilíbrio entre as cadeias laterais do tronco, em comparação a velejadores sem dor lombar. A mobilidade da coluna e a flexibilidade do quadril foram semelhantes entre os grupos.

Hip morphology and its relationship with hip strength, mobility and lower limb biomechanics: a systematic review in adults / Relação da morfologia do quadril com força, mobilidade e biomecânica dos membros inferiores: uma revisão sistemática em adultos

Abstract This systematic review (PROSPERO registration n.43640) aimed to summarise and determine the quality of evidence relating hip bone morphology to (i) hip strength, (ii) mobility and (iii) lower limb biomechanics during functional activities. A standardized search on MEDLINE/PubMed, Web of Science, ScienceDirect and Scopus resulted in 17 papers that met inclusion criteria: i) original investigations with a minimal sample of n=10, ii) studies on humans and iii) presence of at least one quantitative hip morphological parameter and one hip functional (i.e. strength and mobility) and/or one lower limb biomechanical parameter. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies tool with adaptations. Sixteen out of the 17 included studies showed high risk of bias. We observed that primary evidence pointed to the influence of hip morphology on hip mobility in the transverse plane. Specifically, positive correlations between femoral anteversion angle and range of internal hip rotation in physical examination were observed. Regarding biomechanical parameters, no clear evidence of association between hip morphology, and kinematic and kinetic parameters were found. Our results point to a field that is currently under explored and future studies with low risk of bias addressing these relationships are required.

Resumo Essa revisão sistemática (PROSPERO registro no 43640) tem por objetivo sintetizar e determinar a qualidade da evidência que relaciona morfologia do quadril à (i) força do quadril, (ii) mobilidade e (iii) biomecânica dos membros inferiores durante atividades funcionais. Uma busca padronizada no MEDLINE/PubMed, Web of Science, ScienceDirect e Scopus resultou em 17 artigos em acordo com os critérios de inclusão: i) estudos originais com amostra mínima de n=10; ii) estudos em humanos e iii) presença de no mínimo um parâmetro quantitativo da morfologia do quadril e um parâmetro funcional do quadril (ex.: mobilidade e força) e/ou um parâmetro biomecânico do membro inferior. A avaliação do risco de viés foi realizada através da ferramenta Quality Assessment of Diagnostic Accuracy Studies (QUADAS) com adaptações. Dezesseis dos 17 estudos incluídos apresentaram alto risco de viés. Observamos que a evidência primária aponta para influência da morfologia do quadril em sua mobilidade no plano transverso. Foram observadas, especificamente, correlações positivas entre o ângulo de anteversão femoral e a mobilidade de rotação interna do quadril durante o exame físico. Em relação aos parâmetros biomecânicos, não foram encontradas evidências claras sobre associação entre morfologia do quadril e parâmetros cinemáticos e cinéticos. Nossos resultados apontam para um campo atualmente subexplorado e investigações futuras com baixo risco de viés que avaliem essas relações são necessárias.

Prediction of ground reaction forces while walking in water.

Despite being a key concept in rehabilitation, controlling weight-bearing load while walking, following lower limb injury is very hard to achieve. Walking in water provides an opportunity to prescribe load for people who have pain, weakness or weight bearing restrictions related to stages of healing. The aim of this experimental study was to evaluate and validate regression models for predicting ground reaction forces while walking in water. One hundred and thirty seven individuals (24±5 years, 1.71±0.08 m and 68.7±12.5 kg) were randomly assigned to a regression group (n = 113) and a validation group (n = 24). Trials were performed at a randomly assigned water depth (0.75 to 1.35 m), and at a self-selected speed. Independent variables were: immersion ratio, velocity, body mass, and waist, thigh and leg circumferences. Stepwise regression was used for the prediction of ground reaction forces and validation included agreement and consistency statistical analyses. Data from a force plate were compared with predicted data from the created model in the validation group. Body mass, immersion ratio, and velocity independently predicted 95% of the vertical and resultant ground reaction force variability, while, together, velocity and thigh circumference explained 81% of antero-posterior ground reaction force variability. When tested against the data measured in validation samples, the models output resulted in statistically similar values, intraclass correlation coefficients ranging from 0.88 to 0.90 and standard errors of measurement, 11.8 to 42.3 N. The models introduced in this study showed good predictive performance in our evaluation procedures and may be considered valid in the prediction of vertical, antero-posterior and resultant ground reaction forces while walking in water. All predictive variables can be easily determined in clinical practice. Future studies should focus on the validation of these models in specific populations.

A influência do tratamento intensivo com suporte de peso corporal na função motora de crianças com paralisia cerebral / Effects of intensive treatment with body weight support in children with cerebral paralysis

A aquisição da marcha sob o aspecto neuromotor da reabilitação vem a ser o principal desígnio do terapeuta durante a elaboração do plano de tratamento do paciente com paralisia cerebral, uma vez que a marcha representa não só um ganho da habilidade de locomover-se, mas também um conjunto de reações e padrões de movimento que auxiliam na função motora. Objetivo: Analisar os efeitos de um tratamento intensivo por meio do suporte de peso corporal em crianças com paralisia cerebral. Métodos: Participaram do estudo 10 crianças com paralisia cerebral, GMFCS nível IV ou V, idade entre 4 a 9 anos. Onde foram realizadas sessões diárias com suporte de peso corporal em esteira ergométrica com auxílio de terapeutas para executar o padrão de marcha mais próximo da normalidade, com pontos chaves em joelho e tornozelo com duração de 30 minutos de tratamento e intervalo de 24 horas, por um período de 10 dias. Para fins de avaliação pré e pós-intervenção, utilizando a escala de medição da função motora grossa GMFM, e da flexibilidade pelo Flexiteste. Resultados: Foi possível constatar um aumento relevante na função motora grossa dos sujeitos, onde o domínio Deitar e Rolar obteve maior pontuação, com um aumento de 10,77%. Sentar demonstrou aumento de 3,80%, Engatinhar e Ajoelhar 6,43% e o domínio Em Pé 3,45%. Relativo ao Flexiteste, a média entre os sujeitos relatou aumento expressivo de 4,2 pontos. Já em análise individual, percebe-se que 3 indivíduos obtiveram aumento de score de 6 pontos. Conclusão: Um protocolo intensivo de curta duração é capaz de trazer ganhos de flexibilidade e motores rápidos a crianças que possuem quadro de paralisia cerebral.

The acquisition of gait under the neuromotor aspect of rehabilitation is the main goal of the therapist during the elaboration of the treatment plan of the patient with cerebral palsy, since gait represents not only a gain in the ability to move, but also a set of reactions and movement patterns that aid in motor function. Objective: To analyze the effects of intensive treatment by means of body weight support in children with cerebral palsy. Method: Ten children with cerebral palsy, GMFCS level IV or V, age between 4 and 9 years participated in the study. Where daily sessions were performed with body weight support on a treadmill with the help of therapists to perform the walking pattern closest to normal, with key points in the knee and ankle lasting 30 minutes of treatment and 24 hour intervals for one period of 10 days. For purposes of pre and post-intervention evaluation, using the GMFM gross motor function measurement scale, and Flexitest flexibility. Results: It was possible to observe a significant increase in the gross motor function of the subjects, where the lie down and roll domain obtained a higher score, with an increase of 10.77%. To sit demonstrated a 3.80% increase, Crawling and Kneeling 6.43% and the Standing Foot 3.45%. Relative to Flexitest, the mean between subjects reported a significant increase of 4.2 points. In the individual analysis, it was observed that 3 subjects had a 6-point score increase. Conclusions: An intensive short-duration protocol is capable of bringing flexibility gains and fast motor to children with cerebral palsy.

Efeitos da prática do suporte de peso corporal em crianças com paralisia cerebral: uma série de casos / Effects of the practice of the body weight support in children with cerebral paralysis: a series of cases

Introdução: A paralisia cerebral (PC) é a causa mais comum de incapacidade motora na infância. Essa lesão cerebral pode resultar em comprometimentos neuromotores variados que, geralmente, estão associados à gravidade da sequela e a idade da criança. Objetivo: Avaliar a influência do Suporte de Peso Corporal (SPC) sobre a função motora e flexibilidade de crianças com paralisia cerebral. Método: Participaram do estudo sete crianças que não apresentavam o padrão de marcha, GMFCS nível IV e V, onde foi realizada a identificação do desempenho da função motora grossa por meio da Gross Motor Function Measure (GMFM), da flexibilidade por meio do teste Flexiteste,e do número de passos e distância percorrida antes e após um ano de tratamento com SPC em esteira ergométrica. Tendo assistência de dois terapeutas que auxiliavam em pontos chaves de joelho e tornozelo simulando o padrão de marcha da criança. As sessões foram realizadas uma vez por semana, durante 30 minutos. Resultado: O GMFM apresentou aumento das pontuações obtidas antes e após o tratamento, onde os itens deitar e rolar teve aumento de 14,09%, sentar teve aumento de 10,43%, engatinhar e ajoelhar teve, aumento de 7,27%, e por fim, o item em pé teve aumento de 8,10%. A variável flexibilidade apresentou diferença antes e após o tratamento, obtendo como flexibilidade inicial pequena e final médio negativa, com aumento de 7,85 pontos. Já o número de passos teve aumento de 175 passos e a distância percorrida de 132 metros Conclusão: The proposed SPC therapy in children with cerebral palsy proved to be efficient and could enhance motor performance, flexibility, number of steps and distance traveled. [AU]

Introduction: Cerebral palsy (CP) is the most common cause of motor disability in childhood. This brain injury can result in varied neuromotor compromises that are usually associated with the severity of the sequela and the child's age. Objective: To evaluate the influence of the Body Weight Support (SPC) on the motor function and flexibility of children with cerebral palsy. Methods: Seven children who did not present gait pattern, GMFCS level IV and V, participated in the study, where the identification of the gross motor function performance was performed through the Gross Motor Function Measure (GMFM), flexibility using the Flexitest test , and the number of steps and distance traveled before and after one year of SPC treadmill treatment. With assistance from two therapists assisting in key knee and ankle points simulating the child's gait pattern. The sessions were held once a week for 30 minutes. Results: The GMFM showed an increase of the scores obtained before and after the treatment, where the items of throwing and rolling had an increase of 14.09%, sitting had an increase of 10.43%, crawling and kneeling had an increase of 7.27% and finally, the standing item increased by 8.10%. The flexibility variable showed difference before and after treatment, obtaining as initial small flexibility and medium negative end, with increase of 7.85 points. However, the number of steps increased by 175 steps and the distance covered by 132 meters. Conclusion: The proposed physiotherapeutic treatment (SPC) presented to these patients with cerebral palsy was efficient and could increase motor performance, flexibility, number of steps and distance traveled. [AU]

Vertical ground reaction force in stationary running in water and on land: A study with a wide range of cadences.

PURPOSE: The aim of this study was to analyze the effect of cadence, immersion level as well as body density on the vertical component (Fymax) of ground reaction force (GRF) during stationary running (SR). METHODS: In a controlled, laboratory study, thirty-two subjects ran at a wide range of cadences (85-210 steps/min) in water, immersed to the hip and to the chest, and on dry land. Fymax. was verified by a waterproof force measurement system and predicted based on a statistical model including cadence, immersion ratio and body density. RESULTS: The effect of cadence was shown to depend on the environment: while Fymax increases linearly with increasing cadence on land; in water, Fymax reaches a plateau at both hip and chest immersions. All factors analyzed, cadence, immersion level and body density affected Fymax significantly, with immersion (aquatic × land environment) showing the greatest effect. In water, different cadences may lead to bigger changes in Fymax than the changes obtained by moving subjects from hip to chest immersion. A regression model able to predict 69% of Fymax variability in water was proposed and validated. CONCLUSION: Cadence, Immersion and body density affect Fymax in a significant and non-independent way. Besides a model of potential use in the prescription of stationary running in water, our analysis provides insights into the different responses of GRF to changes in exercise parameters between land and aquatic environment.

Efeito da prática do suporte de peso corporal na função motora de crianças / Effect of the practice of body weight support in the motor function of children

Objetivo. Avaliar a influência do Suporte de Peso Corporal (SPC) sobre a função motora de crianças não deambulantes. Método. Participaram do estudo oito crianças que não apresentavam o padrão de marcha. Foi realizada a identificação do desempenho da função motora grossa por meio da Gross Motor Function Classification Measure (GMFM) e da flexibilidade por meio do Teste Flexiteste, antes e após 10 sessões e um período de retenção durante 3 meses de tratamento com SPC em esteira ergométrica. Tendo assistência de dois terapeutas que auxiliavam em pontos chaves de joelho e tornozelo simulando o padrão de marcha da criança. As sessões foram realizadas uma vez por semana, durante 30 minutos, por um período de 3 meses e o mesmo de retenção. Resultado. O GMFM apresentou aumento das pontuações obtidas pré/pós-tratamento e retenção nos itens deitar/rolar e sentar, já o item engatinhar/ajoelhar mostrou diferença significativa apenas no período pré/pós-tratamento. A variável flexibilidade apresentou diferença significativa entre o pré e pós-tratamento e no pós-tratamento com o período de retenção. Conclusão. O tratamento com SPC em esteira ergométrica pode potencializar o desempenho funcional de crianças não-deambulantes, possibilitando a evolução de sua função motora grossa e flexibilidade. (AU)

Objective: To evaluate the influence of the Body Weight Support (SPC) on the gross motor in non-ambulant children. Method: Eight children participated in the study, they did not present gait pattern (GMFCS IV and V). To access the gross motor function, the Gross Motor Function Classification Measure (GMFM) test was applied, the flexibility values were collected through flexitest. Both tests were conducted before and after 10 clinical sessions and three months after the end of the treatment. The intervention were performed on a treadmill, with the subject attached to the SPC, being accompanied by two physiotherapists that helped to maintain the gait pattern by maintaining key positions of the knees and ankles. Each session had duration of 30 minutes, once per week during three months. Results: The GMGM scores for lay down/roll and sit increased after the treatment and on the retention when compared with pre tests. The crawl/kneel score only presented difference after the end of treatment. Flexibility presented higher values for post and retention in comparison with pre tests. Conclusion: The SPC treatment during treadmill gait may potentiate the functional performance of non-ambulant children, improving the gross motor skills and flexibility. (AU)

Analysis of lower limb force in foot work exercise of Pilates / Análise da força de membros inferiores no exercício foot work do método Pilates

Abstract Introduction: Pilates is a physical exercise method that uses the resistance of springs to modulate the overload from exercises. Objective: To characterize the force versus time curve of the foot work exercise; verify and compare the force applied by the same limb during the foot work exercise against the resistance of two types of springs with different elastic constants, and verify and compare the asymmetry of force applied by right and left lower limbs during the foot work exercise against the resistance of the same type of spring. Methods: Twenty healthy adult individuals familiarized with Pilates were evaluated. Two extensometric force plates adapted to the Reformer apparatus were used. Each participant performed 10 repetitions of the exercise against the resistance of two pairs of springs with different elastic constants. Descriptive and inferential statistics were used with significance levels of p < 0.05. Results: The exercise's standard curve showed that the peak force is reached in the point of maximum hip and knee extension during the execution of the exercise. There were differences between force production by the same limb for different springs (p < 0.001) and between left and right limb when spring with lower elastic constant was used (p = 0.006). No differences were found between right and left limb when spring with higher elastic constant was used (p = 0.108). Conclusion: The knowledge of the force versus time curve and the quantification of unilateral force are important elements in the evaluation and prescription of exercises.

Resumo Introdução: O Pilates é um método de exercício físico que utiliza a resistência de molas para modular a sobrecarga dos exercícios. Objetivo: Caracterizar a curva de força versus tempo do exercício foot work; verificar e comparar a força aplicada pelo mesmo membro durante o exercício foot work contra a resistência de dois tipos de molas com constantes elásticas diferentes; e verificar e comparar a assimetria de força aplicada pelos membros inferiores direito e esquerdo durante o exercício foot work contra a resistência do mesmo tipo de mola. Métodos: Foram avaliados 20 indivíduos adultos saudáveis e familiarizados com o Pilates. Utilizou-se duas plataformas de força extensométricas adaptadas ao aparelho Reformer. Cada participante realizou 10 repetições do exercício contra a resistência de dois pares de molas com constantes elásticas diferentes. Utilizou-se estatística descritiva e inferencial, com nível de significância de p < 0,05. Resultados: A curva padrão do exercício demonstra que o pico de força é alcançado no ponto máximo de extensão do quadril e joelho durante a execução do exercício. Houve diferenças entre a produção de força do mesmo membro para diferentes molas (p < 0,001) e entre os membros direito e esquerdo para uma mola de menor constante elástica (p = 0,006). Não foram encontradas diferenças entre os membros direito e esquerdo para uma mola de maior constante elástica (p = 0,108). Conclusão: O conhecimento da curva de força versus tempo e a quantificação da força unilateral são importantes elementos na avaliação e prescrição de exercícios.

Effect of Immersion on Ground Reaction Force and Contact Time During Drop Jump Exercise.

Dell'Antonio, E, Ruschel, C, de Brito Fontana, H, Haupenthal, A, Pereira, SM, and Roesler, H. Effect of immersion on ground reaction force and contact time during drop jump exercise. J Strength Cond Res 30(12): 3443-3449, 2016-This study analyzed the effect of water immersion on vertical ground reaction force (GRF) peaks and contact times during the braking, propulsion, and landing phases of drop jumps (DJs). Twenty-five healthy male athletes of volleyball and track and field (age 18.0 ± 2.4 years) participated in this study. Peak vertical GRF during braking, propulsion, and landing phases; time duration of braking and propulsion phases; and total contact time were measured during maximum DJs performed on land and in water at 4 levels of immersion (tibia, knee, thigh, and hip). A force plate was used to collect GRF data, and the braking and propulsion phases of contact were determined by using an electrical goniometer placed on subject's knee. The effect of immersion level on variables was analyzed through the use of a repeated measures analysis of variance (p ≤ 0.05). The results showed that increasing immersion leads to a decrease in peak force during the braking phase, landing phase, and in the propulsion phase of the DJ, with the decrease in peak forces between immersions being greater as the immersion level gets deeper. Concerning the contact times, increasing immersion levels caused an increase in total contact time and in the duration of the braking phase. No differences were found for the duration of the propulsion phase between the conditions. Our results have shown that temporal features of the DJ were not preserved in water, and this must be taken into account when choosing the aquatic environment as an alternative for plyometric training. If the rationale of performing plyometric training in water is the reduction of GRFs, then hip immersion seems to offer an interesting combination of significantly lower GRF but without further modification of important temporal features when compared with the other water conditions analyzed.

Biomechanical analysis of the contact phase in drop jumps performed in water and on dry land / Análise biomecânica da fase de contato no salto em profundidade no solo e na água

Abstract Plyometric training in the aquatic environment has been used as way of reducing loads through the action of buoyancy. However, little is known about the biomechanical characteristics of plyometric exercises in water, which can assist in the prescription of training in this environment. This study aimed to analyze the vertical component of the ground reaction force and contact duration of drop jumps (DJ) performed on land and at hip level water immersion. Participants were 22 male athletes (19.1 ± 3.7 years), who performed three maximum DJs in water and on dry land. Peak force and duration of braking and propulsion sub-phases of the DJ contact were analyzed with the use of two underwater force platforms, a 2-D waterproofed electrogoniometer, acquisition systems ADS2000-IP and TeleMyo 2400TG2, and a signal synchronizer. The effect of immersion was investigated through comparison tests for dependent samples (p <0.05). In water, the following results were observed: (a) reduction of 41.8% (p <0.001, d = 2.24) and 23.8% (p <0.001, d = 1.50) of peak forces during braking and propulsion sub-phases respectively; and (b) increase of 41.8% in the braking (p <0.001, d = 1.41) and 12.3% in the propulsion contact times (p = 0.006, d = 0.75). The aquatic environment can be an alternative when one aims to reduce the load during the DJ contact; however, the longer duration increasing of contact sub-phases in water at hip immersion may compromise the proper functioning of the stretch-shortening cycle in water.

Resumo O treinamento pliométrico em ambiente aquático tem sido proposto porque reduz as cargas proporcionada pela ação do empuxo. Entretanto, pouco se sabe sobre as características biomecânicas dos exercícios pliométricos na água, as quais podem auxiliar na prescrição do treinamento neste ambiente. Este estudo teve por objetivo analisar a força vertical de reação do solo e a duração do contato do salto em profundidade (SP) realizado no solo e na água. Participaram da pesquisa 22 atletas do sexo masculino (19,1±3,7 anos), os quais executaram três SPs máximos no solo e na água (imersão do quadril). Analisou-se o pico de força e a duração das subfases de frenagem e propulsão do contato do SP com o uso de duas plataformas de força subaquáticas, um eletrogoniômetro 2-D impermeabilizado, os sistemas de aquisição ADS2000-IP e TeleMyo 2400TG2, e um sincronizador de sinais. O efeito do ambiente foi investigado através de testes de comparação para amostras dependentes (p<0,05). Na água, observou-se (a) uma redução de 41,8% (p<0,001; d=2,24) e de 23,8% (p<0,001; d=1,50) do pico de força durante as subfases de frenagem e propulsão, respectivamente; e (b) um aumento de 41,8% na duração da frenagem (p<0,001; d=1,41) e de 12,3% na duração da propulsão (p=0,006; d=0,75) do contato. O ambiente aquático pode ser uma alternativa quando se tem o objetivo de reduzir a carga durante o contato do SP; entretanto, o aumento da duração das subfases do contato pode comprometer o funcionamento adequado do ciclo alongamento-encurtamento na água.

Propulsive force symmetry generated during butterfly swimming / Simetria da força propulsiva gerada pelas mãos durante o nado borboleta

Abstract The aim of the study was to analyze the hand force symmetry in butterfly swimming. Fourteen male and female swimmers (18.4 ± 4.9 years old, 71.8 ± 14.6 kg of body mass, 1.78 ± 0.09 m of height and mean performance that corresponds to 74.9 ± 5.8% of the world record). Subjects performed three trials of 25 m of butterfly swimming at maximal speed. Mean and maximum forces were estimated for each hand using pressure sensors of the Aquanex System (Swimming Technology Research, USA). The comparisons between force values for dominant and non-dominant hands were made through Student’s T test for dependent samples (p<0.05). In addition, the symmetry Index (SI) was calculated as a relative measure of the force applied by each hand. The mean and maximum force for the dominant hand corresponded, respectively, to 55.7 ± 14.7 N and 114.7 ± 39.6 N. For the non-dominant hand, values were 51.2 ± 14.7 N for mean force and 110.7 ± 36.7 N for maximum force. Significant differences were found between dominant and non-dominant hands for both variables (p<0.01). The symmetry index analysis showed mean values of 8.9% for mean force and of 12.6% for maximum force, and most swimmers presented values higher than 10% for mean and/or maximum forces. Further studies should be performed in order to investigate the relationship between hand force symmetry and swimming performance.

Resumo O objetivo do estudo foi analisar a simetria da força dos membros superiores durante a braçada do nado borboleta. Quatorze nadadores de ambos os sexos (18,4 ± 4,9 anos, massa de 71,8 ± 14,6 kg, estatura de 1,78 ± 0,09 m e com média de desempenho correspondente a 74,9 ± 5,8% do recorde mundial) realizaram três execuções de 25 m máximas nadando borboleta. A força média e a força máxima de cada mão foram estimadas através de sensores de pressão do Sistema Aquanex (Swimming Technology Research, EUA). Comparações entre a força produzida pelos lados dominante e não dominante foram realizadas através do teste t de Student para amostras dependentes (p<0,05). Adicionalmente, foi calculado o índice de simetria como uma medida relativa da força aplicada em cada mão. A força média e a força máxima da mão dominante corresponderam, respectivamente, a 55,7 ± 14,7 N e 114,7 ± 39,6 N. Para a mão não dominante, os valores foram de 51,2 ± 14,7 N para a força média e 110,7 ± 36,7 N para a força máxima. Foram encontradas diferenças significativas entre a mão dominante e não dominante para ambas as variáveis (p<0,01). A análise do índice de simetria mostrou valores médios de 8,9% para a força média e de 12,6% para a força máxima, sendo que a maioria dos nadadores apresentou valores maiores do que 10%, para a força média e/ou máxima. Acredita-se que análises futuras devam ser feitas, buscando relações da assimetria com o desempenho de nado.

Effective Swimmer's Action during the Grab Start Technique.

The external forces applied in swimming starts have been often studied, but using direct analysis and simple interpretation data processes. This study aimed to develop a tool for vertical and horizontal force assessment based on the swimmers' propulsive and structural forces (passive forces due to dead weight) applied during the block phase. Four methodological pathways were followed: the experimented fall of a rigid body, the swimmers' inertia effect, the development of a mathematical model to describe the outcome of the rigid body fall and its generalization to include the effects of the inertia, and the experimental swimmers' starting protocol analysed with the inclusion of the developed mathematical tool. The first three methodological steps resulted in the description and computation of the passive force components. At the fourth step, six well-trained swimmers performed three 15 m maximal grab start trials and three-dimensional (3D) kinetic data were obtained using a six degrees of freedom force plate. The passive force contribution to the start performance obtained from the model was subtracted from the experimental force due to the swimmers resulting in the swimmers' active forces. As expected, the swimmers' vertical and horizontal active forces accounted for the maximum variability contribution of the experimental forces. It was found that the active force profile for the vertical and horizontal components resembled one another. These findings should be considered in clarifying the active swimmers' force variability and the respective geometrical profile as indicators to redefine steering strategies.