The aims of this study were: i) to analyze activation patterns of four upper limb muscles (duration of the active and non-active phase) in each lap of 200m breaststroke, ii) quantify neuromuscular fatigue, with kinematics and physiologic assessment. Surface electromyogram was collected for the biceps brachii, deltoid anterior, pectoralis major and triceps brachii of nine male swimmers performing a maximal 200m breaststroke trial. Swimming speed, SL, SR, SI decreased from the 1st to the 3rd lap. SR increased on the 4th lap (35.91 ± 2.99 stroke·min-1). Peak blood lactate was 13.02 ± 1.72 mmol·l-1 three minutes after the maximal trial. The EMG average rectified value (ARV) increased at the end of the race for all selected muscles, but the deltoid anterior and pectoralis major in the 1st lap and for biceps brachii, deltoid anterior and triceps brachii in the 4th lap. The mean frequency of the power spectral density (MNF) decreased at the 4th lap for all muscles. These findings suggest the occurrence of fatigue at the beginning of the 2nd lap in the 200m breaststroke trial, characterized by changes in kinematic parameters and selective changes in upper limb muscle action. There was a trend towards a non-linear fatigue state.

The kinematic analysis of gait during pregnancy provides more information about the anatomical changes and contributes to exercise and rehabilitation prescription. The purposes were to quantify the lower limb kinematics of gait and to compare it between the second and third trimesters of pregnancy and with a control group. A three-dimensional analysis was performed in twenty-two pregnant women and twelve nonpregnant. Repeated Measures and Manova tests were performed for comparisons between trimesters and between pregnant and controls. The walking speed, stride width, right-/left-step time, cycle time and time of support, and flight phases remain unchanged between trimesters and between pregnant and controls. Stride and right-/left-step lengths decreased between trimesters. Double limb support time increased between trimesters, and it increased when compared with controls. Joint kinematics showed a significant decrease of right-hip extension and adduction during stance phase between trimesters and when compared with controls. Also, an increase in left-knee flexion and a decrease in right-ankle plantarflexion were found between trimesters. The results suggested that pregnant women need to maintain greater stability of body and to become more efficient in locomotion. Further data from the beginning of pregnancy anthropometric data may contribute to the analysis.

O estágio foi realizado na época desportiva 2022/2023 no Clube Natação de Rio Maior e este compreendeu dois momentos distintos. No primeiro momento, desempenhei as funções de treinador-adjunto no grupo de alto rendimento, especificamente nas disciplinas de águas abertas e natação pura. Tive a responsabilidade de auxiliar na operacionalização das atividades, intervir nos exercícios desenvolvidos, planear os diferentes ciclos de treino (macro, meso e microciclos), colaborar com a preparação, organização e gestão das competições, e realizar análises de desempenho durante as competições. As vivências e aprendizagens deste estágio foram inigualáveis devido à qualidade de todos os intervenientes envolvidos no grupo de treino e concluo este estágio com a certeza de que foi uma experiência formidável. No segundo momento, desenvolvi um projeto de estudo de natureza científica. O estudo está relacionado com a avaliação biomecânica, mais especificamente à análise de variáveis cinemáticas observadas em diferentes contextos, como a piscina e o Lago de Rio Maior. O objetivo foi analisar o comportamento dos nadadores nas diferentes variáveis cinemáticas no ciclo de nado em contextos diferentes. Este estudo revelou que o comportamento dos nadadores nas diferentes variáveis cinemáticas não foi o mesmo nos diferentes contextos nadados. Além disso, este estudo permitiu implementar séries de treino que conjuguem várias variáveis cinemáticas, como por exemplo a FG e a VN, de acordo com os objetivos pré-definidos, ou seja, realizar séries em que as variáveis cinemáticas estejam de acordo com os ritmos que os nadadores irão encontrar durante as competições.

O objetivo do presente estudo é a comparação das implicações da respiração de orientação e alternada nos nadadores em Águas Abertas, nos parâmetros cinemáticos e musculares numa distância de 5000 m em contexto natural, nomeadamente num lago. A amostra foi constituída por 9 nadadores do sexo masculino (25.4 ± 11.9 anos), massa corporal (75.9 ± 9.0 kg); altura (180.7 ± 6.7 cm); envergadura (185.6 ± 10.3 cm) e com 7 anos de treino e participação no Circuito Nacional de Águas Abertas, realizaram 10x500 metros à máxima intensidade na técnica de crol com intervalo de 30 segundos para verificação do equipamento e abastecimento. As variáveis cinemáticas foram, Frequência Gestual (FG), Velocidade (V), Distância de Ciclo (DC), Índice de Braçada (IB) foram analisadas, bem como a atividade muscular através de eletromiografia de superficie em 7 músculos; Upper Trapezius (UT); Latissimus Dorsi (LD); Pectoral Major (PM); Posterior Deltoid (PD); Anterior Deltoid (AD); Triceps Brachii (TB); Biceps Brachii (BB). Com a realização do teste ANOVA de medidas repetidas, Greenhouse-Geisser, os resultados mostram que existiram diferenças significativas; a FG foi aumentando (17.5-19.5 ciclos-min-1) dos 500m aos 1500m e dos 3500m aos 5000m (F=4.79, p=0.01, η2=0.37); a Velocidade foi diminuindo ao longo do percurso (1.39-1.33 m.s), com aumento nos 4500m até ao final do percurso (F=2.88, p=0.03, η2=0.02), a DC foi diminuindo ao longo do percurso principalmente dos 500m aos 2500m (F=4.47, p=0.00, η2=0.35), o IB foi diminuindo ao longo percurso em particular dos 500m aos 2500m (F=3.78, p=0.01, η2=0.32). Ao nível das alterações musculares, os músculos TB (F=1.84, p=0.07, η2=0.18) e PM (F=4.15, p=0.00, η2=0.34) apresentaram diferenças significativas na ativação no recrutamento muscular ao longo de todo o percurso, na condição respiração alternada em relação às fases subaquáticas e de recuperação. No caso do músculo AD (F=3.65, p=0.00, η2=0.31) acabou por apresentar diferenças significativas ao nível muscular nas distâncias 500m, 1000m, 2000m, 3000m e 5000m, na condição de respiração de orientação em relação a ambas as fases. Os resultados indicam que os nadadores, utilizam como estratégia o aumento da FG e diminuição das restantes variáveis, de modo a controlarem a sua cadência de nado.

O objetivo deste estudo foi comparar as diferenças cinemáticas entre a análise digital 2D e 3D em movimentos do ciclismo que ocorrem maioritariamente no plano sagital. Participaram no estudo 8 indivíduos do sexo masculino, praticantes de ciclismo recreativo, com uma idade de 23± 3 anos, uma altura de 1,70m± 0,05 e um peso de 70kg± 5kg. Os atletas pedalaram numa bicicleta assente em rolos e utilizaram 2 posições de guiador. Foram utilizadas 3 camaras e colocados marcadores reflexivos na bicicleta e no atleta. Os resultados obtidos não evidenciaram diferenças significativas entre os métodos 2D e 3D nas variáveis estudadas, o que nos permite sugerir que em futuras investigações similares possam ser adotados procedimentos de análise 2D, minimizando assim a complexidade dos recursos utilizados e a quantidade de dados a analisar.

O objetivo deste estudo foi comparar as diferenças cinemáticas entre a análise digital 2D e 3D em movimentos do ciclismo que ocorrem maioritariamente no plano sagital. Participaram no estudo 8 indivíduos do sexo masculino, praticantes de ciclismo recreativo, com uma idade de 23± 3 anos, uma altura de 1,70m± 0,05 e um peso de 70kg± 5kg. Os atletas pedalaram numa bicicleta assente em rolos e utilizaram 2 posições de guiador. Foram utilizadas 3 camaras e colocados marcadores reflexivos na bicicleta e no atleta. Os resultados obtidos não evidenciaram diferenças significativas entre os métodos 2D e 3D nas variáveis estudadas, o que nos permite sugerir que em futuras investigações similares possam ser adotados procedimentos de análise 2D, minimizando assim a complexidade dos recursos utilizados e a quantidade de dados a analisar. - The aim of this study was to compare the differences between the kinematic analysis in digital 2D and 3D movements of cycling that occur mostly in the sagittal plane. A sample of 8 males practitioners of recreational cycling, with an age of 23 ± 3 years, height of 1.70 ± 0.05 m and a weight of 70kg ± 5kg. The athletes pedaled a bicycle based on rolls and used 2 position handlebar. We used three cameras and reflective markers placed on the athlete and on the bike. The results showed no significant differences between the methods in 2D and 3D variables, allowing us to suggest that in future similar investigations can be adopted 2D analysis procedures, thus minimizing the complexity of the resources used and the amount of data to analyze.

The aim of the present manuscript was to provide information on the suitability of using ovine as models for conducting in vivo bone tissue engineering studies, regarding the biomechanical considerations. Despite the need of knowledge of the animal model used for bone tissue research a good planning and study design is equal important. The purpose of this review is to contribute to extrapolation of reliable data for those who pretend to use the ovine model in tissue engineering and regenerative medicine.

Background: Foot postural alignment has been associated with altered gait pattern. This study aims to investigate gait kinematic differences in flatfoot subjects’ regarding all lower limb segments compared to neutral foot subjects. Methods: A total of 31 participants were recruited (age: 23.26 yo ± 4.43; height: 1.70 m ± 0.98; weight: 75.14 kg ± 14.94). A total of 15 subjects were integrated into the flatfoot group, and the remaining 16 were placed in the neutral foot group. All of the particpants were screened using the Navicular Drop Test and Resting Calcaneal Stance Position test to characterize each group, and results were submitted to gait analysis using a MOCAP system. Results: Significant kinematic differences between groups were found for the ankle joint dorsiflexion, abduction, and internal and external rotation (p < 0.05). Additionally, significant differences were found for the knee flexion, extension, abduction, and external rotation peak values (p < 0.001). Significant differences were also found for the hip flexion, extension, external rotation, pelvis rotation values (p < 0.02). Several amplitude differences were found concerning ankle abduction/adduction, knee flexion/extension and abduction/adduction, hip flexion/extension and rotation, and pelvis rotation (p < 0.01). Conclusion: Flatfooted subjects showed kinematic changes in their gait patterns. The impact on this condition on locomotion biomechanical aspects is clinically essential, and 3D gait biomechanical analysis use could be advantageous in the early detection of health impairments related to foot posture.

Purpose: The aims of this study were: (i) develop a performance predictor model based on the swimmers’ biomechanical profile; (ii) relate the partial contribution of the main predictors with the training program and; (iii) analyze the time effect, sex effect and time X sex interaction. Methods: Ninety one swimmers (44 boys: 12.04 ± 0.81 years-old, 47 girls: 11.22 ± 0.98 years-old) were evaluated during a 3-year period. The decimal age, anthropometric, kinematic and efficiency features were collected in ten different moments over three seasons (i.e. longitudinal research). Hierarchical linear modeling was the procedure used to estimate the performance predictors. Results: Performance improved between season #1 - early and season #3 - late for both sexes (boys: 26.9% [20.88;32.96]; girls: 16.1% [10.34;22.54]). The decimal age (Estimate: -2.05; P < 0.001), arm span (Estimate: -0.59; P < 0.001), stroke length (Estimate: 3.82; P = 0.002) and propelling efficiency (Estimate: -0.17; P = 0.001) entered in the final model. Conclusion: Our results showed that over three consecutive seasons young swimmers’ performance improved. Performance is a multifactorial phenomenon where anthropometrics, kinematics and efficiency were the main determinants. The change of these factors over time was coupled with the training plans of this talent ID program.

The aim of this study was to compute a swimming performance confirmatory model based on biomechanical parameters. The sample included 100 young swimmers (overall: 12.3 ± 0.74 years; 49 boys: 12.5 ± 0.76 years; 51 girls: 12.2 ± 0.71 years; both genders in Tanner stages 1–2 by self-report) participating on a regular basis in regional and national-level events. The 100 m freestyle event was chosen as the performance indicator. Anthropometric (arm span), strength (throwing velocity), power output (power to overcome drag), kinematic (swimming velocity) and efficiency (propelling efficiency) parameters were measured and included in the model. The path-flow analysis procedure was used to design and compute the model. The anthropometric parameter (arm span) was excluded in the final model, increasing its goodness-of-fit. The final model included the throw velocity, power output, swimming velocity and propelling efficiency. All links were significant between the parameters included, but the throw velocity–power output. The final model was explained by 69% presenting a reasonable adjustment (model’s goodness-of-fit; x2/df = 3.89). This model shows that strength and power output parameters do play a mediator and meaningful role in the young swimmers’ performance.