Percorrer por autor "Zacca, Rodrigo"
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- Biomechanical Features of Backstroke to Breaststroke Transition Techniques in Age-Group SwimmersPublication . Chainok, Phornpot; de Jesus, Karla; Mourão, Luis; Fonseca, Pedro Filipe Pereira; Zacca, Rodrigo; Fernandes, Ricardo J.; Vilas-Boas, João PauloThis study aimed to identify the biomechanical features of backstroke to breaststroke transition techniques (open, somersault, bucket, and crossover) in age-group swimmers. Eighteen preadolescent swimmers (12.2 ± 0.4 years old and 3–4 Tanner stages) underwent 4 weeks of systematic contextual interference training, comprising 16 sessions (40 min·session−1). Soon after, experimental testing was conducted where swimmers randomly performed 12 × 15m maximal turns (composed of 7.5m turn-in and 7.5m turn-out of the wall segments), three in each transition technique. Kinematical, kinetic, and hydrodynamic variables were assessed with a dual-media motion capture system (12 land and 11 underwater cameras), triaxial underwater force plates, and inverse dynamics. Variables were grouped in turn-in (approach and rotation) and turn-out (wall contact, gliding, and pull-out) phases, with factor analysis used to select the variables entering on multiple regressions. For the turn-in phase, 86, 77, 89, and 87% of the variance for open, somersault, bucket, and crossover turning techniques, respectively, was accounted by the 7.5 and 2.5m times, mean stroke length, and rotation time. For the turn-out phase, first gliding distance and time, second gliding depth, turn-out time, and dominating peak_Z push-off force accounted for 93% in open turn, while wall contact time, first gliding distance, breakout distance and time, turn-out time, dominating peak_Y push-off force, and second gliding drag coefficient accounted for 92% in a somersault turn. The foot plant index, push-off velocity, second gliding distance, and turn-out time accounted for 92% in bucket turn while breakout and turn-out time, non-dominating peak_Y and peak_Z push-off force, first and second gliding drag force and second gliding drag coefficient accounted for 90% in crossover turn, respectively. The findings in this study were novel and provided relevant biomechanical contribution, focusing on the key kinematic–temporal determinant during turn-in, rotation, and push-off efficacy, and the kinetic and hydrodynamic during turn-out, which would lead to improved backstroke to breaststroke transition techniques in 11–13 years-old age-group swimmers.
- Movement behaviours, air pollution and health in school-aged children: a cross-sectional study to guide the co-creation of healthier environments – the MOVE-AIR projectPublication . Martins, Clarice; Rufo, João Cavaleiro; Fonseca, Hélder; Padrão, Ana; Baptista, Liliana C.; Santos, Maria Paula; Sousa, Miguel; Zacca, Rodrigo; Silva, José Pedro; Ribeiro, Ana Isabel; Cavaleiro Rufo, JoãoThe MOVE-AIR study was designed to explore the moderating role of movement behaviours on the association between air pollutants and health outcomes in Portuguese children. Secondarily, it aims to characterise the settings (both indoor and outdoor) where children are exposed to air pollutants and to co-create solutions with participants to mitigate the exposure to air pollutants in children’s daily life. This study aims to describe the MOVE-AIR study protocol in detail. Data from 52 primary school children aged 9–11 years will be assessed for indoor and outdoor air pollutants (particulate matter (PM)2.5 and PM10, and carbon dioxide), geo-tracked for distinct settings (ie, home/school, indoor/outdoor) along the day, through an optical monitoring sensor with Global Positioning System incorporated. Health-related biological outcomes, such as interleukin-6, tumour necrosis factor alpha and oxidative parameters, including total antioxidant status and total oxidant status, will be evaluated and the Oxidative Stress Index will be calculated. Children’s cardiopulmonary fitness will be assessed through the shuttle run test, and movement behaviours will be evaluated through accelerometers (wGT3X). Children’s sex, age and parental socioeconomic status will be provided by parents through a questionnaire. The influence of movement behaviours in the link between pollution and health will be analysed through moderating regression models using process for SPSS R software (V.30.0.0). A subsample of class teachers, school leaders, parents and children will be invited to a co-creation process to create solutions to mitigate their daily exposure to air pollutants. The results will contribute to further understanding the moderating role of movement behaviours in the association between air pollution and health, adding a biological layer to the mechanistic links underlying these potential relationships that have not been explored in this target population. Finally, enhancing our comprehension of the living environments and contexts where children are more exposed to air pollution can help to cooperatively create solutions to mitigate their daily exposure to those harmful pollutants.