Browsing by Author "Fernandes, Orlando"
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- Accuracy and interpretation of the acceleration from an inertial measurement unit when applied to the sprint performance of track and field athletesPublication . Miranda-Oliveira, Paulo; Branco, Marco; Fernandes, OrlandoIn this study, we aimed to assess sprinting using a developed instrument encompassing an inertial measurement unit (IMU) in order to analyze athlete performance during the sprint, as well as to determine the number of steps, ground contact time, flight time, and step time using a high-speed camera as a reference. Furthermore, we correlated the acceleration components (XYZ) and acceleration ratio with the performance achieved in each split time obtained using photocells. Six athletes (four males and two females) ran 40 m with the IMU placed on their fifth lumbar vertebra. The accuracy was measured through the mean error (standard deviation), correlation (r), and comparison tests. The device could identify 88% to 98% of the number of steps. The GCT, flight time, and step time had mean error rates of 0.000 (0.012) s, 0.010 (0.011) s, and 0.009 (0.009) s when compared with the high-speed camera, respectively. The step time showed a correlation rate of r = 0.793 (p = 0.001) with no statistical differences, being the only parameter with high accuracy. Additionally, we showed probable symmetries, and through linear regression models identified that higher velocities result in the maximum anteroposterior acceleration, mainly over 0–40 m. Our device based on a Wi-Fi connection can determine the step time with accuracy and can show asymmetries, making it essential for coaches and medical teams. A new feature of this study was that the IMUs allowed us to understand that anteroposterior acceleration is associated with the best performance during the 40 m sprint test.
- Accuracy of inertial measurement units when applied to the countermovement jump of track and field athletesPublication . Miranda-Oliveira, Paulo; Branco, Marco; Fernandes, OrlandoIn this study, we aimed to assess the countermovement jump (CMJ) using a developed instrument encompassing an off-the-shelf Inertial Measurement Unit (IMU) in order to analyze performance during the contraction phase, as well as to determine the jump height and the modified reactive strength index (RSImod), using force plate (FP) data as reference. Eight athletes (six males and two females) performed CMJs with the IMU placed on their fifth lumbar vertebra. Accuracy was measured through mean error (standard deviation), correlation, and comparison tests. The results indicated high accuracy, high correlation (r), and no statistical differences between the IMU and the FP for contraction time (r = 0.902; ρ < 0.001), negative impulse phase time (r = 0.773; ρ < 0.001), flight time (r = 0.737; ρ < 0.001), jump time (r = 0.708; ρ < 0.001), RSImod (r = 0.725; ρ < 0.001), nor minimum force (r = 0.758; ρ < 0.001). However, the values related to the positive impulse phase did not have the expected accuracy, as we used different devices and positions. Our results demonstrated that our developed instrument could be utilized to identify the contraction phase, jump height, RSImod, and minimum force in the negative impulse phase with high accuracy, obtaining a signal similar to that of an FP. This information can help coaches and athletes with training monitoring and control, as the device has simpler applicability making it more systematic.
- A influência do treino proprioceptivo no tempo de latência dos músculos peroniais laterais, gémeo externo e tíbial anteriorPublication . Dias, Amândio; Correia, Pedro; Esteves, José Manuel; Fernandes, Orlando
- New technologies to the study the golf puttingPublication . Fernandes, Orlando; Dias, Gonçalo; Couceiro, Micael; Manuel Clemente, Filipe; M. L. Martins, Fernando; Luz, Miguel; Mendes, RuiThe technology evolution, especially in the last decade, allowed major advances in golf putting analysis. This scientific advance benefited from multidisciplinary interaction, such as: biomechanics, engineering, mathematics and motor control. Utilizing digital cameras along automatic tracking techniques, it is possible to obtain valuable and accurate information about the putting gesture and/or ball trajectory. This can provide relevant feedback to athletes and coaches. In this work, we present several golf putting studies conducted on laboratorial environment. We believe that this work may contribute to a deeper analysis of human motor behavior and performance, not limited to this motor skill, but that can be applied to other motor patterns.
- Prevalence of Lower Back Pain in Portuguese Equestrian RidersPublication . Duarte, Carlota; Santos, R.; Fernandes, Orlando; Raimundo, Armando; Autor correspondente: Santos, R..Lower back pain is prevalent in equestrian athletes, but its prevalence and associated factors are unknown in the Portuguese equestrian population. A questionnaire regarding lower back pain and possible associated factors was answered by 347 respondents. Of the respondents, 214 (61.7%) stated having experienced lower back pain in the past 12 months and therefore completed the Roland Morris disability questionnaire. Among the latter, 63.1% stated that lower back pain impaired their performance. The probability of suffering from lower back pain was higher in individuals with higher weekly riding workloads, who reported equestrianism as their main occupation, and who performed daily stable duties. Considering a Roland Morris disability score of 4 as the cut-off value for dysfunction, this sample had an average score of 5.39 ± 4.42. Individuals who stated equestrianism was their main occupation showed a significantly higher risk (OR = 1.759, p = 0.041) of exhibiting a score ≥ 4 than those who stated equestrianism as a hobby. Age (p = 0.029), body mass index (p = 0.047), and daily performance of stable duties (p = 0.030) were also associated with a higher Roland Morris disability score. Further research is needed to understand the full impacts of lower back pain in Portuguese equestrian athletes.
- The influence of a balance training program on the electromyographic latency of the ankle musculature in subjects with no history of ankle injuryPublication . Dias, Amândio; Correia, Pedro; Esteves, José Manuel; Fernandes, Orlando
- The influence of intraoral devices on static performance in golf athletes : pilot studyPublication . Santos, Luis Xavier; Chéroux, Vera; Cebola, Pedro; Almeida, André; Fernandes, Orlando; Família, Carlos; Félix, Sérgio; Godinho, Catarina
- The influence of intraoral devices on static performance in golf athletes : pilot studyPublication . Santos, Luís Xavier; Chéroux, Vera; Cebola, Pedro; Almeida, André; Família, Carlos; Fernandes, Orlando; Félix, Sérgio; Godinho, Catarina
- The validity of the push band 2.0 on the reactive strength index assessment in drop jumpPublication . Montoro-Bombú, Raynier; Arencibia, Lázaro de la Paz; Buzzichelli, Carlo; Miranda-Oliveira, Paulo; Fernandes, Orlando; Santos, Amândio; Rama, LuisThis study aims to verify the validity of the Push Band 2.0 (PB2.0) device on the reactive strength index (RSI) measurement, using a force plate (FP) and an optical sensor device, OptoJump (OPT), as a reference. Twenty trained athletes performed 60 drop jump trials with a height box of 30 cm. A randomized repeated measures study was conducted during a single session using the PB2.0, the OPT, and the plate force manually synchronized to obtain RSI data for each jump. Validity was analyzed by contrasting three measures: the intra-class correlation coefficient (ICC), the Bland–Altman test, and R2 coefficient of determination. Bland–Altman analysis showed that RSI and FP for PB2.0 (media = −0.047; IC 93.34%) of all data were within the confidence interval, indicating a statistically reliable result. The RSI measured by the OPT and PB2.0 also provided similar values (media = −0.047). These data are identical to other validity measures (ICC and linear correlation) but differ in the R2 values. The explained variation of PB2.0 measures attained only 29.3% of the FP (R2 = 0.293) and 29.5% (R2 = 0.295) of the OPT assessment, showing a very low determination coefficient. The results of this study point to caution in the use of PB2.0 when measuring RSI in scientific research.