Dr. Ulloa-Diaz, David

2022, Dr. Ulloa-Diaz, David, Chirosa-Ríos, I., Chirosa Rios, L., Martínez-García, D., Herbawi, F., Jerez-Mayorga, D., Baena-Morales, S., Rodríguez-Perea, A.

El objetivo de este estudio fue determinar el efecto de la técnica de secuencias de bracing en la estabilidad del core y el rendimiento en kata de karatecas. 38 deportistas masculinos de karate participaron en el estudio divididos en un grupo experimental (n=21) y un grupo de control (n=17). La prueba de rendimiento del deportista y la prueba de estabilidad del core se realizaron en pretest y postest posterior a 8 semanas de programa de estabilidad del core (técnica de secuencias de bracing). El grupo experimental mostró una mejora significativa en la prueba de rendimiento del atleta (p < 0,001) y en la prueba de estabilidad del core con (p < 0,05). Hubo una correlación positiva muy fuerte entre la prueba de rendimiento del atleta y el cinturón del karateca (ρ =0.780), una correlación positiva considerable entre la prueba de estabilidad del core y el cinturón del jugador (ρ =0.604), una correlación positiva considerable entre la prueba de rendimiento del atleta y la edad del jugador (ρ=0.554), y una correlación positiva media entre la prueba de estabilidad del core y la edad del jugador (ρ=0.481). En conclusión, los karatecas mostraron una gran mejora en el rendimiento del kata y en el nivel de estabilidad del core después del programa de técnicas de secuencias de bracing.

2023, Andrades-Ramírez, Oscar, Zambrano-Cáceres, Bernardo, Marchant-Medina, Yovanny, Constanzo Rojas, Miguel, Castillo-Paredes, Antonio, Alfaro-Castillo, Bryan Sebastián, Ulloa-Diaz, David

La percepción de la clase de educación física por parte de los estudiantes es un factor importante porque dependiendo de cómo los escolares perciban estas vivencias, se generarán determinadas creencias o valoraciones, las que influyen en la actitud para enfrentar estas experiencias corporales cada vez que se presenten. 176 estudiantes (14.74 ± 0.68), pertenecientes a los establecimientos particulares subvencionados de la comuna de Coronel. El objetivo de esta investigación es analizar la percepción actitudinal subjetiva de los estudiantes de enseñanza secundaria hacia los profesores de EF. Para evaluar la percepción actitudinal de los estudiantes hacia el profesor de educación física, se utilizó una modificación del cuestionario de actitudes de los escolares hacia la educación física. En los resultados de la actitudes positivas, se puede indicar que el alumnado valoro mayormente el ítem “Muy de acuerdo” en la pregunta “Mi profesor/a de educación física sabe mucho”, en las actitudes negativas la pregunta “Mi profesor/a de educación física levanta la voz frecuentemente” fue el mayor porcentaje en el ítem “Muy de acuerdo” . En el análisis comparativo entre hombres y mujeres para la percepción positiva reporto (p = 0.63) y negativa (p = 0.10). En el análisis por edades para la escala positiva (p = 0.01), para la escala negativa (p = 0.25). El alumnado observo mayormente actitudes positivas de y muy pocas negativas en el profesor de educación física, sin observase diferencias entre hombres y mujeres, en las edades se reportaron diferencias en las actitudes positivas y negativas del profesor, informando que los alumnos de con más edad evalúan más críticamente las actitudes positivas y negativas del profesor de EF.

2019, García-Ramos, Amador, Ulloa-Diaz, David, Barboza González, Paola, Rodríguez Perea, Ángela, Martínez García, Darío, Quidel Catrilelbún, Mauricio, Guede Rojas, Francisco, Cuevas-Aburto, Jesualdo, Janicijevic, Danica, Weakley, Jonathon

This aims of this study were (I) to determine the velocity variable and regression model which best fit the load-velocity relationship during the free-weight prone bench pull exercise, (II) to compare the reliability of the velocity attained at each percentage of the one-repetition maximum (1RM) between different velocity variables and regression models, and (III) to compare the within- and between-subject variability of the velocity attained at each %1RM. Eighteen men (14 rowers and four weightlifters) performed an incremental test during the free-weight prone bench pull exercise in two different sessions. General and individual load-velocity relationships were modelled through three velocity variables (mean velocity [MV], mean propulsive velocity [MPV] and peak velocity [PV]) and two regression models (linear and second-order polynomial). The main findings revealed that (I) the general (Pearson’s correlation coefficient [r] range = 0.964–0.973) and individual (median r = 0.986 for MV, 0.989 for MPV, and 0.984 for PV) load-velocity relationships were highly linear, (II) the reliability of the velocity attained at each %1RM did not meaningfully differ between the velocity variables (coefficient of variation [CV] range = 2.55–7.61% for MV, 2.84–7.72% for MPV and 3.50–6.03% for PV) neither between the regression models (CV range = 2.55–7.72% and 2.73–5.25% for the linear and polynomial regressions, respectively), and (III) the within-subject variability of the velocity attained at each %1RM was lower than the between-subject variability for the light-moderate loads. No meaningful differences between the within- and between-subject CVs were observed for the MV of the 1RM trial (6.02% vs. 6.60%; CV ratio = 1.10), while the within-subject CV was lower for PV (6.36% vs. 7.56%; CV ratio = 1.19). These results suggest that the individual load-MV relationship should be determined with a linear regression model to obtain the most accurate prescription of the relative load during the free-weight prone bench pull exercise.

2015, Carrasco Beltrán, Hernaldo, Reigal Garrido, Rafael E., Ulloa-Diaz, David, Chirosa Ríos, Ignacio Jesús, Chirosa Ríos, Luis Javier

The regular practice of physical activity contributes to weight control and improves maximal oxygen uptake (VO2max), socialization and quality of life. Aim: To determine the effect of moderate-to-vigorous physical activity on body composition and VO2max in a group of overweight school-age males. Material and Methods: We studied fifty-five overweight males aged 15.6 ± 0.7 years. Participants were divided in two groups (experimental and control groups). The intervention in the experimental group was the practice of small-sided games during 60 minutes, two days per week and during 11 weeks. At baseline and the end of the intervention, body composition was measured using bioimpedance and VO2max was calculated using the Course Navette test. Results: A 7% reduction in the percentage of body fat and a 9% increase in VO2max were observed in the experimental group (p < 0.01). No changes were recorded in the control group. Conclusions: Eleven weeks of small-sided exercises performed twice per week increased VO2max and reduced fat mass in overweight adolescents.

2022, Andrades-Ramírez, Oscar, Alfaro-Castillo, Bryan, Martínez-García, Darío, Dr. Cuevas-Aburto, Jesualdo, Dr. Ulloa-Diaz, David, Chirosa-Ríos, Luis

El estudio tiene como propósito analizar la fiabilidad de la prueba de 8 lanzamientos de 3 diferentes variantes de lanzamientos de balonmano en estudiantado universitario. 33 varones, 20 ±1,9 años peso 72,39±8,9 kg altura 176,75 ±6,07 cm IMC 23,14±2,3. Los sujetos participantes fueron evaluados en 2 sesiones separadas entre sí por un lapso de una semana. Ejecutaron lanzamientos hasta quedar registrados 8 mediciones en cada una de las pruebas, lanzamientos inespecíficos, en apoyo y en carrera con 3 pasos, se registró la velocidad de lanzamiento con un radar posterior a la portería. La fiabilidad del promedio de las puntuaciones del test de 8 medidas entre la primera sesión y la segunda con una prueba test-retest, se obtuvieron los siguientes resultados: en el lanzamiento inespecífico se obtuvo un ICC= (0,86) entre el 95% de confianza, un de CV= (7,43%) y un ES= (0,08). Para el lanzamiento con apoyo se obtuvo un ICC= (0,94) al 95 % de confianza, un de CV= (4,71 %) y un ES= (-0,09). Para el lanzamiento con carrera se obtuvo un ICC= (0,96) al 95 % de confianza, un de CV= (4,00 %) y un ES= (0,05). Este estudio ha demostrado que la prueba de 8 lanzamientos y las 3 variantes es una medida de rendimiento confiable y estable para estudiantes de nivel universitario sin experiencia en el balonmano, en relación con las variables del lanzamiento, las 3 fueron fiables, solo la variable inespecífica fue menor en comparación al lanzamiento con apoyo y con carrera.

2024, Dr. Ulloa-Diaz, David, Andrades-Ramírez, Oscar, Guede-Rojas, Francisco, Araya-Sierralta, Sergio, Muñoz-Bustos, Gustavo, Arroyo-Jofré, Patricio, Chirosa-Ríos, Luis-Javier

Background: The Chilean population has experienced increased longevity in recent decades, leading to an increased incidence of and mortality from neurodegenerative diseases such as Parkinson’s disease (PD). PD is a chronic degenerative condition that affects the central nervous system. The main objective of this research is to evaluate the effect of 12-week programs of tonic, isometric, and isometric/vibratory muscular strength training while controlling the manipulation of the intensity variable on motor and non-motor symptomatology in PD patients. The secondary objective is to assess the levels of muscular strength in PD patients and their relationship with motor and non-motor symptomatology. Methods: A parallel-group, randomized trial will randomly assign (n = 34) people of both sexes with Parkinson’s disease between stages I–III Hoehn and Yahr (H&Y), aged between 50 and 70 years to one of the experimental groups, in which they will undergo a total of 24 strength training sessions during 12 weeks. During the intervention period, the participants will be advised not to undertake additional exercise programs, to avoid substances that may disrupt metabolism and circadian cycles, and to maintain their medication regimen. The primary or motor evaluation of rest tremor will be performed with an accelerometer (Actigraphy), balance with the Mini-BESTest balance test, gait speed with the Ten Meters Walk Test, and non-motor symptomatology through anxiety, depression (MDS-UPDRS), and quality of life (PDQ-39) questionnaires. The Secondary evaluation of muscle strength will be performed with a functional electromechanical dynamometer. Discussion: Established as a hypothesis is that manipulating intensity variables in 12-week tonic, isometric, and isometric/vibratory muscle strength training programs has an effect on motor and non-motor symptomatology in people with Parkinson’s disease. The research will establish the extent to which controlled muscular strength training has an effect on relevant factors related to motor and non-motor symptomatology.

2024, Dr. Ulloa-Diaz, David, Cifuentes-Zapata, Claudio, Andrades-Ramírez, Oscar, Rodríguez-Perea, Ángela, Huerta-Ojeda, Álvaro, Chirosa-Ríos, Luis

Background: Systematizing reliable protocols and procedures for strength assessment in handball has allowed for a more thorough kinetic analysis and increased precision in detecting training-induced changes in muscular strength. The evaluation of upper limb strength with a bilateral standing press (BSP) exercise in handball players approximates blocking actions in the defensive phase, pushing and fixation. Aim: The aim of this study was to analyze the relative and absolute reliability of intra-session comparisons in an isometric peak muscle strength protocol in a bilateral standing press (BSP) exercise among female handball players. Methods: Sixteen young female handball players at an international level, aged between 22 ± 4 years, with no prior experience in using functional electromechanical dynamometers (FEMD) participated in this study. The participants initiated the assessment of maximum isometric force in a bipedal stance with a forward projection of the dominant foot between 20 and 30 cm. The knees were kept semi-flexed, and the hip extension of the non-dominant limb ranged from 15 to 20°. Bilateral anterior push of the upper limb was performed with shoulder abduction and elbow flexion at 90°, maintaining a pronated hand position. Participants were instructed to exert three sets of maximal force for 5 s in BSP exercise. Relative reliability was assessed using the model intraclass correlation (ICC) and absolute reliability was assessed using the coefficient of variation (CV) and standard error of measurement (SEM). For this study, the parameters of maximum and mean muscle strength were considered. Results: The results demonstrated high relative reliability (ICC 0.93–0.97) and absolute reliability (SEM 0.19–2.79) y (CV 4.78–9.03) for both mean force and peak force, with no significant differences between the sets (p > 0.05), indicating a negligible effect size (0.01−0.12). Conclusion: The mean and peak isometric muscle strength for the BSP exercise controlled with FEMD in female handball players exhibits high relative and absolute reliability between series.

2020, Guede Rojas, Francisco, Jerez Mayorga, Daniel, Ulloa-Diaz, David, Soto Martínez, Adolfo, Ramírez Campillo, Rodrigo, Barboza González, Paola, Angarita Dávila, Lissé

Background: The functional fitness of older people may be associated with their nutritional status. Aim: To assess the association between of anthropometric measures with functional fitness in older people. Material and Methods: Cross-sectional study conducted in 75 participants aged 65 to 89 years. Body mass index (BMI), waist-to-height ratio (WHtR), fat mass (FM) and skeletal muscle mass index (SMI) were calculated from anthropometric measures. The functional fitness was determined using the Senior Fitness Test battery. Results: BMI and FM indicated obesity, and WHtR indicated cardiometabolic risk in 49%, 55% and 83% of participants, respectively. SMI indicated a low muscle mass in 91% of females. Performance standards of chair stand, arm curl, 2-min step test and 8-foot up-and-go tests were met in 1%, 8%, 1% and 89% of participants, respectively. Significant negative correlations were found between 2-min step test and BMI, WHtR and FM (r = −0.26, −0.31 and −0.48 respectively). Back scratch had a negative correlation with BMI (r = −0.23) and SMI (rho = −0.28). Significant positive correlations were found between 8-foot up-and-go, WHtR (rho = 0.28) and FM (rho = 0.23), and between 2-min step test and SMI (rho = 0.28). The coefficient of determination (R2) between 2-min step test with BMI, WHtR and FM were 0.05, 0.08 and 0.22, respectively, while the R2 between back scratch and BMI was 0.04. Multiple regression models indicated that FM affected the 2-min step test independently of BMI and WHtR (adjusted R2 = 0.22), however age and sex negatively influenced these associations. Conclusions: Functional fitness of older adults is influenced by nutritional anthropometric measures, particularly BMI, WHtR and FM for aerobic capacity, and BMI for upper limb flexibility.

2024, Andrades-Ramírez, Oscar, Dr. Ulloa-Diaz, David, Alfaro Castillo, Bryan, Arroyo-Jofré, Patricio, Castillo-Paredes, Antonio, Chirosa-Ríos, Luis

The purpose of the study was to analyze the test–retest reliability of an isometric and isometric/vibratory muscular strength protocol in the bilateral seated bench press (BSBP), bilateral seated rowing (BSR), unilateral seated right knee extension (USKER), and left knee extension (USKEL) tests controlled using functional electromechanical dynamometry (FEMD) in healthy young adults. A repeated measures design was used to determine the reliability of a muscular strength protocol in isometric and isometric vibration modes with FEMD. No significant differences were found in test–retest analysis (p > 0.05; ES < 0.20); and high reliability (CV = 4.65–5.02%; ICC = 0.99–0.98) was found for BSBP measures, and acceptable reliability (CV = 3.71–9.61%; ICC = 0.98–0.95) was found for BSR, USKER, and USKEL. Furthermore, the coefficients between the two measures were strong (r = 0.963–0.839) and highly significant (p = 0.001) for maximal strength in the isometric and maximal isometric/vibratory assessment of muscle strength in all muscle strength tests. This study demonstrates that isometric and maximal isometric/vibratory strength in the BSBP, BSR, USKER, and USKEL tests can be measured with high reliability and reproducibility using the FEMD.

2020, Martinez Garcia, Dario, Rodriguez Perea, Angela, Barboza, Paola, Ulloa-Diaz, David, Jerez Mayorga, Daniel, Chirosa, Ignacio, Chirosa Ríos, Luis Javier

Background. The evaluation of the force in internal rotation (IR) and external rotation (ER) of the shoulder is commonly used to diagnose possible pathologies or disorders in the glenohumeral joint and to assess patient’s status and progression over time. Currently, there is new technology of multiple joint isokinetic dynamometry that allows to evaluate the strength in the human being. The main purpose of this study was to determine the absolute and relative reliability of concentric and eccentric internal and external shoulder rotators with a functional electromechanical dynamometer (FEMD). Methods. Thirty-two male individuals (21.46 ± 2.1 years) were examined of concentric and eccentric strength of shoulder internal and external rotation with a FEMD at velocities of 0.3 m s−1 and 0.6 m s−1 . Relative reliability was determined by intraclass correlation coefficients (ICC). Absolute reliability was quantified by standard error of measurement (SEM) and coefficient of variation (CV). Systematic differences across velocities testing circumstances, were analyzed with dependent t tests or repeated measures analysis of variance in case of two or more than two conditions, respectively. Results. Reliability was high to excellent for IR and ER on concentric and eccentric strength measurements, regardless of velocity used (ICC: 0.81–0.98, CV: 5.12–8.27% SEM: 4.06–15.04N). Concentric outcomes were more reliable than eccentric due to the possible familiarization of the population with the different stimuli. Conclusion. All procedures examined showed high to excellent reliability for clinical use. However, a velocity of 0.60 m s−1 should be recommended for asymptomatic male patients because it demands less time for evaluation and patients find it more comfortable.