Paulo Ricardo Miranda Oliveira
Verified @egasmoniz.edu.pt
Fisioterapia/Egas Moniz School of Health & Science | Mecânica/ESTG-Politécnico de Leiria
Egas Moniz School of Health & Science, Almada, Portugal | ESTG-Politécnico de Leiria, Leiria, Portugal | Federação Portuguesa de Atletismo, Oeiras, Portugal
RESEARCH INTERESTS
Biomechanics applied to sports science
Biomechanics applied to health science
Scopus Publications
Scopus Publications
Raynier Montoro-Bombú, Paulo Miranda-Oliveira, Maria João Valamatos, Filipa João, Tom JW Buurke, Amândio Cupido Santos, and Luis Rama
PeerJ
Background General expectations speculated that there are differences between drop jump (DJ) and horizontal drop jump (HDJ) exercises. While these criteria may be valid, we have yet to find a report that explores these differences in competitive level athletes. Objective The study aimed to compare spatiotemporal variables in the drop jump (DJ) vs. the horizontal drop jump (HDJ) in elite jumpers and sprinters. Methods Sixteen international-level male athletes performed two DJ attempts at different fall heights 0.3, 0.4, and 0.5 m (DJ30, DJ40, and DJ50), and after 2 h, they performed two HDJ attempts (HDJ30, HDJ40, HDJ50). All jumps were performed on a Kistler force plate. The variables analyzed were ground contact time (GCT), flight time (FT), eccentric phase time, concentric phase time, and time to peak concentric force. Results The GCT was found to be significantly shorter in DJ vs. HDJ (Z = 4.980; p = 0.0001; ES = 3.11). FT was significantly lower in DJ30 versus HDJ30 (Z = 4.845; p = 0.0001, d = 3.79), but significantly higher in DJ40 vs. HDJ40 (Z = 4.437; p ≤ 0.0001, d = 3.70) and in DJ50 vs. HDJ50 (Z = 4.549; p ≤ 0.0001, d = 4.72). Conclusions It is concluded that the HDJ requires more time for force production, that the eccentric component requires more time than the concentric and that it is not recommended to use the HDJ over the DJ for reactive purposes. This is the first study that comprehensively compare the differences between DJ and HDJ, which will assist coaches and researchers in the design of future training strategies.
Paulo Miranda-Oliveira, Marco Branco, and Orlando Fernandes
MDPI AG
In 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.
Paulo Miranda-Oliveira, Flávia Costa, Diogo Correia, Milena Vieira, Rui B. Ruben, and Orlando Fernandes
Springer Nature Switzerland
Paulo Miranda-Oliveira, Marco Branco, and Orlando Fernandes
MDPI AG
In 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.
Raynier Montoro-Bombú, Lázaro de la Paz Arencibia, Carlo Buzzichelli, Paulo Miranda-Oliveira, Orlando Fernandes, Amândio Santos, and Luis Rama
MDPI AG
This 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.
Paulo Miranda-Oliveira, Marco Branco, Orlando J. Fernandes, and Rita Santos-Rocha
Informa UK Limited
ABSTRACT The aims were: (1) to determine the accuracy and time-consuming of the automatic digitalization feature of 3D motion analysis systems; and (2) to determine the reliability of the 3D position when a football player performed a hard kick with spin. Four high-speed cameras (Casio ZR200 (512x384)) with a 240 Hz field rate were used. Automatic scanning of the Kinovea® and APAS® software was used. The accuracy was determined through mean absolute error, maximum absolute error, mean standard deviation of absolute error, and the variability values. The reliability was calculated with the Intra-Class Correlation. The mean absolute error (3.62 to 3.78 mm), maximum absolute error (9.09 to 11.61 mm), mean standard deviation of absolute error (0.01 to 0.59 mm), variability values (<1 mm), and the auto-digitalization time (16 to 31 minutes) were calculated and were within the values obtained in the literature. The reliability was determined with the Intra-Class Correlation, and the results were higher than 0.90, warrantied a high consistency for chosen software. The accuracy and the reliability intra-operator were determined, and the results indicated that it is possible to apply the free 3D camera system, with consistency in free-kick analysis.