Research Outputs

Now showing 1 - 10 of 30
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Effects of Non-Immersive Virtual Reality Exercise on Self-Reported Pain and Mechanical Hyperalgesia in Older Adults with Knee and Hip Osteoarthritis: A Secondary Analysis of a Randomized Controlled Trial

2025, Guede-Rojas, Francisco, Mendoza, Cristhian, Rodríguez-Lagos, Leonardo, Soto-Martínez, Adolfo, Dr. Ulloa-Díaz, David, Jorquera-Aguilera, Carlos, Carvajal-Parodi, Claudio

Background and Objectives: Osteoarthritis (OA) of the knee and hip is a major cause of pain and functional impairment. This study evaluated the effects of non-immersive virtual reality (NIVR) combined with conventional physical therapy (CPT) on pain intensity, mechanical hyperalgesia, and perceived recovery in older adults with OA. Materials and Methods: Sixty older adults with mild-to-moderate knee or hip OA were randomly assigned to a NIVR group (NIVR-G; n = 30) or a CPT group (CPT-G; n = 30). Both groups completed 30 sessions over 10 weeks (3 sessions/week). The NIVR-G performed 20 minutes of exergames integrated into CPT. Pain intensity was assessed using the Visual Analog Scale (VAS), and mechanical hyperalgesia was evaluated through pressure pain thresholds (PPTs). Secondary outcomes included the Global Rating of Change (GRoC) and the minimal clinically important difference (MCID) for the VAS. This study is a secondary analysis of a randomized controlled trial registered at ClinicalTrials.gov (ID: NCT05839262). Results: The NIVR-G demonstrated significant reductions in pain intensity after 30 sessions (p < 0.05, d = 1.50), with greater improvements compared to the CPT-G (p < 0.05, d = 1.17). The MCID for the VAS was established at 9.2 mm, with a higher proportion of responders in the NIVR-G (p < 0.05). The NIVR-G also reported superior recovery perception on the GRoC scale (p < 0.05). No significant changes in PPTs were observed in either group. However, the improvements in the NIVR-G diminished four weeks post-intervention. Conclusions: NIVR exergames combined with CPT significantly reduced pain intensity, improved perceived recovery, and resulted in a higher proportion of responders compared to CPT alone. These findings support the use of NIVR as an effective adjunct to CPT in older adults with OA; however, further research is needed to optimize its long-term benefits.

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Effectiveness of Exergames on Functional Physical Performance in Older Adults with Knee/Hip Osteoarthritis: A Randomized Controlled Trial

2025, Carvajal-Parodi, Claudio, Mendoza, Cristhian, Alvarez, Cristian, Soto-Martínez, Adolfo, Dr. Ulloa-Díaz, David, Jorquera-Aguilera, Carlos, Guede-Rojas, Francisco

Background/Objectives: Osteoarthritis (OA) is a leading cause of mobility impairment in older adults, yet few studies have explored exergames (EXGs) as a complementary therapy for knee and/or hip OA (KOA/HOA). This study evaluated the effects of integrating EXGs into conventional therapy (CT) on functional mobility. Methods: Sixty participants were randomized into an EXG/CT group or a CT-only group. The interventions lasted 10 weeks (3 sessions/week), and the EXGs were selected from the interactive game Ring Fit Adventure (Nintendo Switch®, Kyoto, Japan). Results: Functional mobility (Timed Up and Go test) significantly improved in the EXG/CT group but not in the CT group. Additionally, lower-limb strength and aerobic endurance increased in the EXG/CT group. No adverse events were reported, and the adherence was high. Conclusions: These findings support EXG-based interventions as a viable complement to CT. Future studies should design OA-specific EXGs and include patient subgroups to expand the impact of interventions using virtual systems.

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Intra-session reliability of knee flexion-extension muscle strength monitored using a functional electromechanical dynamometer in female soccer players

2025, Andrades-Ramírez, Oscar, Dr. Ulloa-Díaz, David, Alfaro-Castillo, Bryan, Saavedra-Ibaca, Vanessa, Muñoz-Bustos, Gustavo, Chirosa-Ríos, Luis-Javier

Background: The aim of the study was to analyze the relative and absolute reliability of intra-session comparisons of three repetitions in a protocol for assessment peak muscle strength in a knee extension and flexion exercise in competitive female soccer players. Methods: The participants in this research are professional level female soccer players. Peak muscle strength was assessed with functional electromechanical dynamometry (FEMD) for the knee muscles with the following movements: knee flexion (FLE) and extension (EXT). Each movement was assessed at a speed of 0.4 m·s-1 unilaterally, recording peak muscle strength values in the concentric phase (CON) and an eccentric phase (ECC). Results: Null differences (ES < 0.19) were detected in the measurements of peak muscle strength of the extensors and flexors of the right and left knee in their concentric or eccentric phases. In the intra-set reliability measures, they reported acceptable absolute reliability (CV% < 9.71) and extremely high relative reliability (ICC = 0.92–0.98). Conclusion: In relation to the results of this study, it can be concluded that the FEMD presents a high relative and absolute intra-series reliability for the evaluation of muscle strength in knee extension and flexion in female soccer players. These reported antecedents may facilitate a more specific evaluation of the function of the muscles of the lower limbs.

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Effects of High-Intensity Interval Training on Blood Pressure Levels in Hypertensive Patients: A Systematic Review and Meta-Analysis of Randomized Clinical Trials

2024, Romero-Vera, Luis, Dr. Ulloa-Díaz, David, Araya-Sierralta, Sergio, Guede-Rojas, Francisco, Andrades-Ramírez, Oscar, Carvajal-Parodi, Claudio, Muñoz-Bustos, Gustavo, Matamala-Aguilera, María, Martínez-García, Darío

Objective: This systematic review and meta-analysis aimed to (I) evaluate the evidence on the effects of high-intensity interval training (HIIT) on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in hypertensive patients; (II) determine whether HIIT impacts SBP and DBP differently; and (III) assess the clinical relevance of these effects. Methods: A comprehensive search was conducted across multiple electronic databases, resulting in the inclusion of seven randomized clinical trials in the meta-analysis. The outcomes were analyzed using random-effects models to compute mean differences (MD) and standardized mean differences (SMD) for SBP and DBP. Results: A small reduction in SBP was observed with HIIT interventions (MD −3.00; 95% CI −4.61 to −1.39; p < 0.0001; SMD −0.28; 95% CI −0.42 to −0.13; p = 0.0003). However, no statistically significant reductions were detected for DBP (MD −0.70; 95% CI −1.80 to 0.39; p = 0.21; SMD −0.07; 95% CI −0.22 to 0.08; p = 0.35). Despite demonstrating statistical significance for SBP, the effects did not reach clinical relevance. Conclusions: HIIT interventions yield small reductions in SBP, with minimal impact on DBP. These findings suggest limited clinical relevance in the management of hypertension. Further randomized controlled trials are necessary to standardize HIIT protocols, with specific emphasis on intensity control and manipulation, to better understand their potential role in hypertensive populations.

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Effect of an Intra-Sets Variable Resistance Potentiation Protocol on Throwing Speed in Elite Female Handball Players

2025, Cifuentes-Zapata, Claudio, Andrades-Ramírez, Oscar, Dr. Ulloa-Díaz, David, Huerta Ojeda, Álvaro, Barahona-Fuentes, Guillermo, Jorquera-Aguilera, Carlos, Chirosa-Ríos, Luis-Javier

The peak velocity of an athlete’s throws is a determining factor for sports performance. The aim of this study was to analyze the effects of a post-activation performance enhancement (PAPE) protocol with functional electro-mechanical dynamometry (FEMD) on throwing velocity. Thirteen international-level female handball players voluntarily participated in the study. The PAPE protocol considered four sets of eight repetitions controlled by FEMD (four at 30% of 1RM followed by another four at 60% of 1RM). After each series, the athletes’ throwing velocity was measured. Significant differences (p < 0.01) were found in the effect size (ES), which measures the strength of the statistical relationship between two variables by group with the repeated measures ANOVA statistic with an effect size ω2 = 0.028. The effect size analysis identified measurements that are considered null for the baseline—PAPE 1 comparison and small baseline—PAPE 2, baseline—PAPE 3, and baseline—PAPE 4. When resistance is controlled during the run as with an FEMD device, only two sets of eight repetitions (four repetitions at 30% and four repetitions at 60% of 1RM) are required for the improvement of throwing speed in elite handball players.

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Efecto de la manipulación de las variables que configuran el estímulo del entrenamiento de fuerza sobre los síntomas motores en personas con enfermedad de Parkinson: una revisión sistemática

2025, Andrades-Ramírez, Oscar Andrés, Dr. Ulloa-Díaz, David, García-Ramos, Amador, Martínez-García, Darío, Muñoz-Bustos, Gustavo Alejandro, Chirosa-Ríos, Luis Javier

Introducción: La enfermedad de Parkinson (EP) es una enfermedad neurodegenerativa multisistémica que afecta al sistema nervioso central. Las personas con enfermedad de Parkinson (PEP) tienen síntomas tanto motores como no motores. El ejercicio físico es una de las intervenciones no farmacológicas más prometedoras para complementar el tratamiento médico en la PEP. Objetivo: Realizar una revisión sistemática para analizar el efecto del entrenamiento de fuerza (EF) muscular sobre los síntomas motores y describir cómo se manipularon las variables que configuran el EF en estudios realizados con PEP. Métodos: Se realizó una revisión sistemática de la literatura de acuerdo con las pautas del Manual Cochrane para Revisiones Sistemáticas. Los estudios se identificaron mediante búsquedas en cuatro bases de datos electrónicas: Web of Science, Scopus, PubMed y EBSCOhost. La calidad metodológica de los artículos seleccionados se evaluó mediante la lista de verificación de la escala PEDro. Los estudios incluidos obtuvieron una puntuación a≥ 6. La investigación fue registrada en Revisiones Sistemáticas (INPLASY). Número de registro: INPLASY2022110079. Resultados: La búsqueda preliminar arrojó 2830 estudios. Se consideraron veinte artículos, después de revisar el resumen y el texto completo. Siete estudios fueron rechazados por no registrar algunas de las variables de entrenamiento de fuerza requeridas y tres fueron rechazados por utilizar entrenamiento suplementario al entrenamiento de fuerza. Un total de diez estudios cumplieron los criterios de inclusión. Los programas de entrenamiento de fuerza se implementaron 2 - 3 veces por semana, con intensidades entre 30 % - 90 % 1RM, un volumen de entrenamiento de 1 - 3 series y 4 - 20 repeticiones, sesiones de entre 35 - 90 minutos con mejoras significativas en el temblor en reposo, medidas de la marcha, bradicinesia y equilibrio. Conclusiones: Independientemente de cómo se configuró el estímulo del EF, existen mejoras significativas de los síntomas motores en la PEP. Estos resultados promueven la implementación del entrenamiento de fuerza en PEP, pero, debido al bajo número de estudios (10) y la alta variabilidad en la manipulación de las variables que configuran el estímulo del entrenamiento de fuerza, es difícil saber cuál es la prescripción óptima para mejorar los síntomas motores de la PEP.

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Effects of different tonic, isometric and isometric/vibratory strength training programs on motor symptomatology in people with Parkinson’s disease: Study protocol for a randomized trial

2024, Dr. Ulloa-Díaz, 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.

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Immersive Virtual Reality-Based Exercise for Pain Management in Fibromyalgia: An Exploratory Study with Risk of Poor Outcomes Stratification

2025, Carvajal-Parodi, Claudio, Arias-Álvarez, Gonzalo, Dr. Ulloa-Díaz, David, Romero-Vera, Luis, Andrades-Ramírez, Oscar, Guede-Rojas, Francisco, Ponce-González, Jesús G.

Fibromyalgia (FM) is characterized by persistent widespread pain that severely impacts quality of life. Immersive virtual reality-based exercise (iVRE) is emerging as a therapeutic modality for chronic pain management. However, research on iVRE in FM patients has primarily focused on perceived pain intensity (PI), with limited exploration of underlying analgesic mechanisms. This study aims to explore the effects of iVRE on PI, considering risk of poor outcomes (RPO) stratification, and on mechanical pain sensitivity (MPS) in FM. A single-arm, uncontrolled, pre-post-test exploratory study was conducted in subjects with FM. The intervention included 2 weekly 15-min iVRE sessions for 6 weeks. PI (numeric rating scale [NRS]) and MPS (pressure pain thresholds [PPTs] at the upper trapezius, lumbar spine, and knee) were assessed at baseline, after the first session (to assess exercise-induced hypoalgesia), and postintervention. RPO was assessed using the Keele STarT MSK Tool. Eleven participants completed the study. No adverse effects were reported. Clinically important reductions were observed in PI (mean difference [MD]: −2.36, 95% CI: [−4.15, −0.58], d = 0.89; p < 0.05) with this effect being associated with baseline RPO. No observable changes were found in PPTs (all 95% CIs included 0, p > 0.05). In this sample, iVRE appears to reduce PI but not PPTs, suggesting the persistence of MPS and limitations in activating endogenous pain inhibitory mechanisms. Further randomized controlled trials with larger samples are needed to corroborate these results.

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Hydration Status of Elite Youth Soccer Players: Training Versus FIFA Competition

2025, Jorquera-Aguilera, Carlos, Droppelmann-Díaz, Guillermo, Romero-Vera, Luis, Andrades-Ramírez, Oscar, Barrientos-Bustamante, César, Jofré-Acevedo, Carlos, Silva-Rojas, Jaime, Araya-Sierralta, Sergio, Dr. Ulloa-Díaz, David

Optimal hydration is crucial for maintaining health and athletic performance in young soccer players. This requires constant monitoring by medical and sports teams during training sessions and competitions. Objective: The purpose of this study was to examine hydration status based on variations in body weight, fluid intake, and urine specific gravity during three training sessions and a FIFA competition in elite U-17 youth soccer players, national team members. Methods: Twenty-one elite soccer players, aged 17.2 ± 0.29 years, with a body weight of 72.1 ± 6.95 kg and a height of 1.80 ± 0.05 m, participated in the study. To determine hydration status, percentage weight loss, fluid intake, and urine density were measured during three training sessions and one FIFA-level competition. Results: Differences in body weight were observed in two of the training sessions, with greater variation in the competition (3.5% of BW, p < 0.001). Significant differences were found between weight losses in training sessions vs. matches. An increase in initial weight was associated with lower urine density. Regression coefficients showed that differences in body weight can predict urine density during training and competition (p < 0.05). A decrease in final body weight could be a valid indicator as a predictor of higher urinary density.

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Test–Retest Reliability of an Isometric and Isometric/Vibratory Muscular Strength Protocol with Functional Electro-Mechanical Dynamometry

2024, Andrades-Ramírez, Oscar, Dr. Ulloa-Díaz, 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.