Browsing by Author "Fernandes, Ricardo J."
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- Beyond low back pain! The influence of physical activity on mental health, reflected in the functionality of people with low back painPublication . Parolini, Franciele; Becker, Klaus; Goethel, Márcio; Fernandes, Ricardo J.; Fonseca, Hélder; Ervilha, Ulysses F.; Vilas-Boas, João Paulo; Santos, RubimPsychological factors play a crucial role in the experience of acute low back pain and may influence functional outcomes. However, the interplay between these factors and levels of physical activity remains poorly understood. This cross-sectional observational study examined the relationship between psychological variables and functional disability in individuals with acute low back pain, considering different levels of physical activity. Data were collected from 1021 participants through an online platform between 8 June 2022 and 8 April 2023. Standardized instruments were used to assess functional limitations, emotional distress (depression, anxiety, and stress), daily pain catastrophizing, and physical activity levels. A canonical correlation analysis was conducted to explore the multivariate associations between psychological and functional variables. There was a statistically significant association between higher levels of emotional distress and greater functional impairment related to low back pain. This association was observed in both the light-physical-activity group (canonical coefficient = 0.266; p = 0.017), the moderate-physical-activity group (0.237; p = 0.092), and the vigorous-physical-activity group (0.177; p = 0.013). Participants engaging in vigorous physical activity exhibited more favorable psychological profiles and lower functional disability compared to those with lower levels of activity. Regular and vigorous physical activity appears to be a protective factor for mental health and may help reduce functional disability in individuals with acute low back pain. These findings underscore the importance of considering physical activity levels when addressing psychological and functional outcomes in this population.
- 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.
- Breaking barriers: Artificial intelligence interpreting the interplay between mental illness and pain as defined by the International Association for the Study of PainPublication . Parolini, Franciele; Goethel, Márcio; Becker, Klaus; Fernandes, Cristofthe; Fernandes, Ricardo J.; Ervilha, Ulysses F.; Santos, Rubim; Vilas-Boas, João PauloLow back pain is one of the main causes of motor disabilities and psychological stress, with the painful process encompassing sensory and affective components. Noxious stimuli originate on the periphery; however, the stimuli are recombined in the brain and therefore processed differently due to the emotional environment. To better understand this process, our objective was to develop a mathematical representation of the International Association for the Study of Pain (IASP) model of pain, covering the multidimensional representation of this phenomenon. Data from the Oswestry disability index; the short form of the depression, anxiety, and stress scale; and pain catastrophizing daily questionnaires were collected through online completion, available from 8 June 2022, to 8 April 2023 (1021 cases). Using the information collected, an artificial neural network structure was trained (based on anomaly detection methods) to identify the patterns that emerge from the relationship between the variables. The developed model proved to be robust and able to show the patterns and the relationship between the variables, and it allowed for differentiating the groups with altered patterns in the context of low back pain. The distinct groups all behave according to the main finding that psychological and pain events are directly associated. We conclude that our proposal is effective as it is able to test and confirm the definition of the IASP for the study of pain. Here we show that the fiscal and mental dimensions of pain are directly associated, meaning that mental illness can be an enhancer of pain episodes and functionality.
- Effective swimmer’s action during the grab start techniquePublication . Mourão, Luis; Jesus, Karla de; Roesler, Hélio; Machado, Leandro J.; Fernandes, Ricardo J.; Vilas-Boas, João Paulo; Vaz, Mário A. P.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.
- Towards a de facto nonlinear periodization: extending nonlinearity from programming to periodizingPublication . Afonso, José; Clemente, Filipe Manuel; Ribeiro, João; Ferreira, Miguel; Fernandes, Ricardo J.Planning is paramount in sport. Among different philosophical approaches to planning, periodization is a highly popular concept that refers to structured training periods with ensuing programs encompassing moments of progressively-loaded training, followed by recovery; it is normally deemed paramount to optimize adaptations and performance. While planning provides generic guidelines, periodization refers to the sequencing/ordering of training periods to enforce a given plan, therefore referring to longer temporal scales, and programming refers to more micro-scale aspects. In fact, similar periodization schemes may implement distinct programming strategies. Literature on the topic has used the linear and nonlinear terms to describe the content of periodized programs. However, these concepts have not been clearly defined in the literature, which may lead to inaccurate and misleading interpretations. Moreover, nonlinear periodization is usually using nonlinear programming, but with pre-stipulated sequencing of the training periods. Finally, it can be argued that nonlinearity has been an integral part of periodization since its inception, at least theoretically. In this essay, the literature was critically reviewed to better understand the validity of the linearity and nonlinearity concepts as applied in currently proposed periodization models. In addition, a novel approach for a de facto nonlinear periodization is presented.