Publications by authors named "Jerez-Mayorga D"

Background: Shoulder pain is one of the most common musculoskeletal complaints in overhead athletes. This study investigated the prevalence of the main risk factors and sex differences related to the development of shoulder pain in a cohort of amateur overhead athletes.

Hypothesis: The external rotation/internal rotation (ER/IR) isometric strength ratio <0.

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Background: There is limited evidence about exercise performance during postoperative immobilization. This study aimed to quantify the muscle activity in the immobilized shoulder girdle in an abduction and neutral rotation position during a battery of contralateral activities and ipsilateral exercises of the upper limb in healthy volunteers and patients with unilateral shoulder pain (USP).

Methods: Thirty participants were included and grouped as without ( = 17) or with USP ( = 13).

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Article Synopsis
  • Sedentary lifestyles lead to decreased muscle mass and strength, but plyometric jump training (PJT) may help counter these effects, although the ideal training volume for less athletic individuals is unclear.* -
  • A study with 44 participants used a four-week PJT program, comparing a control group and two training groups, one of which performed 50% fewer jumps than the other.* -
  • Results showed that the higher volume training group significantly improved muscle strength and had better tendon properties compared to the control and reduced volume groups, indicating that around 2,414 jumps were effective for muscle strength improvements, while 1,207 jumps positively affected tendon properties.*
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Background: This study aimed to examine the effects of a six-week of concurrent training using high-intensity interval plus resistance training on flow-mediated dilation and pulse wave velocity in hypertensive, elevated blood pressure, or normotensive. A secondary goal was to analyze the inter-individual variability.

Methods: A randomized controlled clinical trial was executed with 60 adult participants distributed across six groups: three control groups of hypertensive, elevated blood pressure, or normotensive and other three experimental hypertensive, elevated blood pressure, and normotensive groups, each comprising n=10 individuals.

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Change of directions (COD) involves multidirectional and complex actions, with performance influenced by multiple factors. As lower limb strength is one of the most determinant of COD performance, the present study aimed to (a) explore the differences in strength outcomes across different lower limb muscle actions between faster and slower basketball players in COD actions at different angles and (b) analyse the relationship between isometric, concentric and eccentric strength outcomes and COD performance at different cutting angles. Twenty-five basketball players (44% female) completed a battery of tests, encompassing isokinetic and isometric squat strength assessments, along with COD tests at 45°, 90° and 180°.

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There is evidence that promoting school physical activity (PSPA) benefits children and adolescents, but little is understood about how this promotion may relate to academic achievement and school climate across varying levels of socioeconomic status (SES). Hence, the study aimed to address this knowledge gap by examining two main objectives: (1) determining the association between PSPA and academic achievement and school climate according to schools' SES and (2) exploring the potential mediating role of PSPA in the relationship between schools' SES and academic achievement and school climate. This cross-sectional study at the school level focused on 4,990 schools (including public, subsidized, and private schools) that participated in the National Educational Study 2018 (Chile), which was applied to primary schoolchildren (4th grade, aged 8-10 years).

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Purpose: to explore lower limb muscle activity concerning limb dominance, as well as variations in force and power during the standing up and sitting down phases of the instrumented sit-to-stand-to-sit test in sedentary individuals, across isokinetic and isotonic modalities.

Methods: 33 sedentary individuals underwent testing using a functional electromechanical dynamometer in both isokinetic and isotonic modes, accompanied by surface electromyography.

Results: In the isokinetic mode, the non-dominant gastrocnemius medialis and vastus medialis exhibited significantly (p < 0.

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Obesity is a major health burden worldwide. Although bariatric surgery (BS) is recognized as an effective strategy for weight loss and comorbidities improvement, its impact on muscle strength and quality is still unclear. We aimed to examine postoperative changes in muscle strength and quality and their relationship with body mass index (BMI) changes among adults undergoing BS.

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Article Synopsis
  • - The study investigates the relationship between muscle oscillation frequency and lower limb muscle strength, power, and work during specific functional tasks among sedentary individuals.
  • - Using a myotonometer, researchers evaluated the oscillation frequencies of key muscles (gastrocnemius medialis, biceps femoralis, and vastus medialis) in both dominant and non-dominant legs of 34 participants before they performed sit-to-stand tasks.
  • - Results indicated that oscillation frequencies in isotonic mode were positively correlated with muscle performance metrics (like peak force and power) for the biceps femoralis and gastrocnemius medialis, highlighting the importance of isotonic assessments for understanding muscle capabilities in sedentary
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Background: The aim of this study was to compare the reliability and agreement between two devices - Wii Fit Balance Board (WBB) versus Hand-Held Dynamometer (HHD) to measure isometric strength during the athletic shoulder (ASH) test in healthy amateur rugby players.

Methods: Fifteen males (23.73 ± 2.

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Most of the existing research has focused on jump plyometrics, where landing reaction forces must be dissipated among lower limb articulations. In contrast, the investigation of resisted plyometrics without jumping, devoid of such landing forces, remains relatively limited. This study aimed to (i) investigate the impact of resisted plyometrics without jumping at two knee flexion angles (60 and 90 degrees) on vastus muscle activity relative to limb dominance and (ii) assess strength, power, and work during the concentric-eccentric phases of these exercises.

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Background: A greater motivation for coaches to be more involved in assessment could be the development of specific strength tests closer to specific handball tasks. Therefore, the aims were to determine the reliability of a handball specific strength test battery in young handball players using a functional electromechanical dynamometer (FEMD) and to evaluate the association between the strength test battery and performance measurements.

Methods: Thirty-two young handball players (25% males and 75% females) performed a repeated-measurement design over four weeks.

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Barrera-Domínguez, FJ, Martínez-García, D, Jerez-Mayorga, D, Chirosa-Ríos, LJ, Almagro, BJ, and Molina-López, J. Vertical versus horizontal training for improving the change of direction speed in adult basketball players: a systematic review and meta-analysis. J Strength Cond Res XX(X): 000-000, 2023-The ability to perform changes of direction (COD) is a complex skill that involves the application of multiple force-orientations, and its execution at maximum speed is crucial in basketball players.

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Article Synopsis
  • Current strength assessment devices in handball may lack specificity and reliability, but functional electromechanical dynamometry offers a new method for accurate strength testing.
  • A study involving 14 male handball players examined the reliability of three strength tests—unilateral pullover, standing lift, and step forward—using this advanced technology over three testing sessions.
  • Results indicated high or acceptable reliability for force measurements, with only minor differences observed between the left and right sides, confirming the tests as viable for evaluating physical performance alongside regular training.
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Context: The aim of this study was to analyze the muscle activity of the hamstring muscles and the lateral gastrocnemius during different variants of the single-leg bridge (SLB) in futsal players.

Design: Cross-sectional study.

Methods: Twenty-two futsal players (age = 24.

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Article Synopsis
  • * Results indicate that adolescents with higher MQI levels experience lower depression, anxiety, and stress, along with reduced abdominal obesity.
  • * The findings suggest a significant inverse association between MQI and mental health issues, implying that better muscle quality may correlate with improved psychosocial well-being among adolescents.
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The purposes were to synthesize as much scientific evidence as possible to determine the effect of core training on balance, throwing/hitting velocity or distance, and jumping in healthy subjects, identify the possible differences between isolated and combined core training on performance and study training and sample variables related to performance. PRISMA guidelines were followed, and a systematic search was performed in the Scopus, Web of Science, Sports Discuss, and PubMed databases with no date restrictions until November 2022. The studies were considered for this meta-analysis following PICO; a) randomized control trials and randomized allocation studies with healthy subjects and > 12 years old b)isolated or combined core training programs with a minimum of 4 weeks in length; c) athletic performance outcomes for balance, throw/hit, and jump variables should be measured; d) sufficient data to calculate effect sizes.

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Background: Trunk rotator strength plays an important role in sports performance and health. A reliable method to assess these muscles with functional electromechanical dynamometer has not been described. Therefore, the objectives of this paper were (I) to explore the reliability of different strength variables collected in isokinetic and isometric conditions during two trunk rotator exercises, and (II) to determine the relationship of isometric and dynamic strength variables collected in the same exercise.

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To evaluate the effects of exergames added to a conventional physical therapy (CPT) program on functional fitness and dynamometric muscle performance for the sit-to-stand (STS) maneuver in older adults and to compare their results concerning a CPT-only intervention. Fifty independent older adults were randomly assigned to CPT and exergames (CPT+ExG group;  = 25; age = 71.8 ± 6.

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The main objective of this study was to determine the differences in energy expenditure (EE) according to sex during and after two different squat training protocols in a group of healthy young adults. Twenty-nine Sports Sciences students volunteered to participate in this study. They attended the laboratory on four different days and completed four sessions: two sessions with 3 sets of 12 repetitions at 75% of their one-repetition maximum (RM) and two sessions with 3 sets of 30 repetitions at 50% of their 1RM.

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The purpose of this systematic review was: a) to determine the quality of evidence from studies assessing the effects of different lower limb strengthening protocols on muscle activity, strength, and power in sedentary and/or physically inactive subjects; and b) to determine the effectiveness of lower extremity strengthening protocols on muscle activity, strength, and power in sedentary and/or physically inactive subjects. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with strength training, lower limb, sedentary, and physical inactivity. Four databases were used: Medline via PubMed, Web of Science, Scopus and SPORTDiscus.

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Background: Low back pain is one of the leading causes of disability globally, with a high economic and social burden. A decrease or imbalance in trunk strength has been associated with the occurrence of low back pain and its severity. Trunk strength training is helpful in the treatment of Non-specific low back pain (NSLBP) patients.

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The aim of this study was to compare the effects of sit-to-stand (STS) training programs with 5 . 10 repetitions on muscle architecture and muscle function in sedentary adults. Sixty participants were randomly assigned into three groups: five-repetition STS (5STS), 10-repetition STS (10STS), or a control group (CG).

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Background: Cognitive dysfunction is a common complain in patients with fibromyalgia (FM).

Aim: To assess the perceived cognitive function and cognitive performance in women with FM.

Material And Methods: Cross-sectional study including 100 women with FM (FMG) and 100 healthy controls (CG).

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Article Synopsis
  • - The study investigates the Muscle Quality Index (MQI) in severely obese patients, linking it to metabolic syndrome markers and cardiorespiratory fitness (CRF).
  • - Results show that patients with low MQI have higher abdominal obesity, increased systolic blood pressure, and lower CRF compared to those with high MQI.
  • - MQI serves as a partial mediator in the relationship between abdominal obesity and systolic blood pressure, indicating its potential role in assessing health risks in morbidly obese individuals.
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