Search Results (81)

Background: The coordination between the upper and lower limbs is essential for athletic performance. However, the structural features that influence coordination difficulty remain insufficiently understood. Few studies have systematically analyzed how task components such as the directional congruence or rhythm structure affect inter-limb coordination. Objective: This study aimed to clarify the structural factors that influence the difficulty of upper–lower limb coordination tasks under rhythmic constraints and to explore the feasibility of applying such tasks in future coordination assessments. Methods: Eighty-six male high school baseball players performed six Rhythm Jump tasks combining fixed upper limb movements with varying lower limb patterns. The task performance was analyzed using three indices: full task success, partial success, and average successful series. One year later, a follow-up test involving 27 participants was conducted to evaluate the reproducibility and sensitivity to the performance change. Results: The task difficulty was significantly affected by structural features, including directional incongruence, upper limb static holding, and rhythmic asynchrony. The tasks that exhibited these features had lower success rates. Some tasks demonstrated moderate reproducibility and captured subtle longitudinal changes in the performance. Conclusions: The results highlight the key structural factors contributing to coordination difficulty and support the potential applicability of Rhythm Jump tasks as a basis for future assessment tools. Although further validation is necessary, this study provides foundational evidence for the development of practical methods for evaluating inter-limb coordination. Full article

In this article, we provide a comprehensive review of machine learning-based sports analytics in baseball. This review is primarily guided by the following three research questions: (1) What baseball analytics problems have been studied using machine learning? (2) What data repositories have been used? (3) What and how machine learning techniques have been employed for these studies? The findings of these research questions lead to several research contributions. First, we provide a taxonomy for baseball analytics problems. According to the proposed taxonomy, machine learning has been employed to (1) predict individual game plays; (2) determine player performance; (3) estimate player valuation; (4) predict future player injuries; and (5) project future game outcomes. Second, we identify a set of data repositories for baseball analytics studies. The most popular data repositories are Baseball Savant and Baseball Reference. Third, we conduct an in-depth analysis of the machine learning models applied in baseball analytics. The most popular machine learning models are random forest and support vector machine. Furthermore, only a small fraction of studies have rigorously followed the best practices in data preprocessing, machine learning model training, testing, and prediction outcome interpretation. Full article

Background/Objectives: In overhead throwing sports such as baseball and softball, upper extremity injuries are prevalent at both collegiate and high school levels. Currently, there is no universal assessment protocol to identify athletes at risk for injury or to determine their readiness to return to sport. This study aimed to investigate the relationship between shoulder internal rotation (IR) and external rotation (ER) isometric strength in a throwing position and three upper extremity functional tests among collegiate baseball players. It was hypothesized that there would not be significant correlations between shoulder IR and ER peak isometric force and the following functional assessments: the Upper Quarter Y Balance Test (YBT-UQ), seated single-arm shot put, and Closed Kinematic Chain Upper Extremity Strength Test (CKCUEST). Methods: Forty healthy collegiate baseball players volunteered for the study. After completing a self-guided warm-up, participants performed bilateral isometric shoulder IR and ER strength tests at 90 degrees of shoulder abduction and elbow flexion, followed by the three functional tests in random order. Relationships were analyzed using Pearson’s correlation coefficients (r), with a significance level set at p < 0.05. Results: Correlations were generally low, ranging from r = 0.001 to r = 0.551. Significant correlations were observed between the CKCUEST and dominant IR strength (r = 0.345, p = 0.031), dominant ER strength (r = 0.407, p = 0.010), and non-dominant ER strength (r = 0.551, p < 0.001). Additionally, a significant correlation was found between the dominant ER/IR strength ratio and the dominant arm superolateral reach on the YBT-UQ (r = −0.352, p = 0.026). No significant correlations were identified between isometric shoulder strength and the single-arm shot put. Conclusions: Most correlations were low to moderate, and only significant correlations between shoulder rotation isometric strength and one direction of the YBT-UQ and the CKCUEST were observed. Thus, shoulder rotation strength in a position similar to the cocking phase of overhead throwing may be valuable for return-to-sport criteria and injury screening for overhead athletes. However, further research is needed to validate these findings. Full article

Background/Objectives: The repetitive overhead throwing of baseball stresses the posterior shoulder, including the rotator cuff and capsule, causing stiffness, tissue thickening, and dysfunction. Previous studies on collegiate baseball players have linked these changes to glenohumeral internal rotation deficits, pain, and injuries. However, these studies primarily used acoustic radiation force impulse-based shear wave elastography (SWE), which has limitations, including tissue heating and lack of portability. The acute effects of pitching on infraspinatus (ISP) muscle elasticity in high school pitchers remain unclear. Therefore, this study aimed to evaluate the acute impact of pitching on ISP muscle elasticity in high school baseball pitchers using continuous SWE (C-SWE), which is a safer and more portable method. The relationship between ISP muscle elasticity and pitching load was also examined. Methods: ISP muscle shear wave velocity (SWV), shoulder range of motion, and strength were evaluated in high school baseball pitchers. The participants were categorized into pitching and non-pitching groups based on whether they pitched with full effort on the day of their medical checkup. C-SWE was used to assess ISP muscle elasticity. Results: The pitching group had considerably higher ISP muscle SWV on the dominant side than the non-pitching group (p = 0.008). A significant positive correlation was observed between pitch and ISP muscle SWV (r = 0.467, p = 0.003). Conclusions: Repetitive pitching acutely increases ISP muscle stiffness in high school pitchers, contributing to posterior shoulder tightness. C-SWE is a safe and practical method for assessing tissue elasticity and developing injury prevention strategies. Full article

Background/Objectives: Shoulder pain is one of the most common injuries among athletes who perform overhead movements. The Athletic Shoulder Test (ASH) has been validated to measure isometric shoulder strength in rugby and baseball players but has not yet been applied to swimmers, where the prevalence of shoulder pathologies reaches up to 91%. The present study aims to validate the ASH and Inverse Athletic Shoulder Test (iASH) in swimmers and establish general values for both tests. Methods: A total of 21 swimmers from the Galician and Asturian Swimming Federation were evaluated using the ASH and iASH tests, measuring strength in three positions (180°, 135°, and 90°). Relative reliability was analysed using the Intraclass Correlation Coefficient (ICC), absolute reliability was assessed through the Standard Error of Measurement (SEM) and Minimal Detectable Change at 90% confidence (MDC90), and variability was determined using the Coefficient of Variation (CV%), applying statistical tests such as Wilcoxon. Results: The ASH and iASH tests demonstrated excellent reliability (ICC = 0.9) across all positions, with acceptable variability (CV% < 35%). No statistically significant differences were found between the preferred and non-preferred side (p > 0.05), except in the iASH test at 180°, where a difference was observed (p = 0.007). The SEM values ranged from 4.39 to 7.39 N, while the MDC90 varied between 10.22 and 17.19 N, ensuring the tests’ sensitivity in detecting real changes in shoulder strength. Conclusions: The ASH and iASH tests are reliable tools for assessing shoulder strength in swimmers and can be used to monitor muscular imbalances and prevent injuries. The symmetry in strength between both sides supports their applicability in preventive programmes. Full article

Background: Bone mineral density (BMD) is crucial for bone health, contributing up to 50% of total bone mineral content during childhood and pre-adolescence, with the accumulation of bone mass in youth significantly impacting adult bone health. Physical activity, especially impact exercise, plays a fundamental role in strengthening bones. Objectives: The aim of this meta-analysis was to study the effects of basketball practice on BMD compared to other sports and free activity practice in children and adolescents. Methods: Observational studies were selected up to January 2024. A total of 492 articles were identified, of which 9 met the criteria for inclusion in the meta-analysis. Results: The BMD increase favored the group of basketball players in the total body (MD 0.07; CI 0.04 to 0.09; p < 0.001; I² = 93%), upper limbs (MD 0.10; CI 0.008 to 0.12; p < 0.001; I² = 96%), and lower limbs (MD 0.05; CI 0.03 to 0.07; p < 0.001; I² = 80%). Conclusions: Basketball practice in children and adolescents appears to be one of the most effective sports for enhancing BMD (total body and upper and lower limbs) compared to football, swimming, combat sports, other team sports, such as baseball and volleyball, as well as athletics and gymnastics. The high heterogeneity among studies, largely due to differences in sports, may limit the interpretation of the findings. Full article

Background: A commonly observed phenomenon is that although the players in a baseball team have received the same training content and volume, their batting performance is quite different. As no optimal solution exists for this problem at present, this study attempted to explore the potential of heart rate variability biofeedback (HRVB) to reduce anxiety and improve batting performance in university baseball players. Materials and Methods: A total of 18 college baseball players were randomly divided into an experimental group and a control group. Both groups answered questionnaires and had their physiological signals and batting performance measured on the first and last days of the experiment (i.e., days 0 and 10, respectively). Only the experimental group received HRVB training between the first and last days (10 days in total). Results: The results showed that before training, no significant differences were found in physiological, psychological, or performance parameters between the two groups. Compared to the control group, following HRVB training, the experimental group showed a notable decrease in cognitive anxiety (before HRVB: 23.56 ± 4.07; after HRVB: 20.11 ± 4.78; p < 0.05) and their batting performance improved significantly (batting score increased from 9.8 ± 11.7 to 19.8 ± 12.0 after HRVB; p < 0.05). Conclusions: This study validated that the use of HRVB can help to improve batting performance and reduce anxiety in college baseball players. Therefore, HRVB can be applied before competition matches, helping the players to perform better. Full article

In ball game sports, binocular visual function is important for accurately perceiving the distance of various objects in visual space. However, the temporal coordination of binocular eye movements during saccades has not been investigated extensively in athletes. The purpose of the present study was to compare the characteristics found in the interocular timing differences in horizontal saccades between ball game players. The participants included 32 university baseball players and 54 university soccer players. They were asked to shift their gaze to the onset of the light-emitting diodes located at 10 deg of visual field eccentricity to the left and right and alternated every 2 s. Horizontal movements of the left and right eyes were recorded separately with the electro-oculogram. Temporal variables for each eye were calculated with digital differentiation, and timing differences between the left and right eyes were compared between participant groups. The overall results showed significant interocular differences between left and right eye movements for the temporal variables of binocular saccades. The comparison between the participant groups revealed that baseball players had smaller interocular timing differences between the left and right eyes than soccer players in the onset time, time to peak velocity, duration, and peak velocity. These results suggest that baseball players have a higher degree of temporal coordination in binocular eye movements, particularly during the initial phase of horizontal saccades, compared to soccer players. This enhanced coordination might be attributable to the sport-specific visual demands of baseball, where players require precise stereoscopic vision to track a small high-speed ball within their visual space. Full article

In this qualitative study, we examined the experiences of Rafael, a professional baseball player diagnosed with attention deficit hyperactivity disorder (ADHD), a prevalent neurodevelopmental condition. Through an extensive interview with the participant, our research aimed to determine how baseball can effectively support individuals with this diagnosis in overcoming their obstacles. Qualitative analysis of the verbal data revealed four interconnected themes—Formative Years and Key Experiences, Dealing with ADHD, Learning through Baseball, and Navigating Life Today—highlighting how the sport has served as a vital developmental and supportive activity for this athlete. Baseball ameliorated Rafael’s personal growth and self-regulation, transforming his challenges into opportunities for resilience and self-mastery. The study emphasizes the importance of physical team activities, particularly baseball, as a beneficial strategy for individuals with neurodevelopmental challenges and recommends further research into the long-term effects and mechanisms through which sports can alleviate symptoms associated with ADHD and related diagnoses. Full article

(1) Background: Glenohumeral internal and external rotational range-of-movement deficits (GIRDs and GERDs) are some of the primary outcomes used to determine the risk of injury in overhead athletes, such as tennis players. Nevertheless, the current testing position does not consider the fact that most tennis actions are repeated at 45° of abduction, and actively. The aim of this study was to establish normative values of pathological GIRDs and GERDs in tennis players and to provide normative values for both the passive and active rotational range of motion of the glenohumeral joint at 90° and 45° of abduction. (2) Methods: Forty-three tennis players voluntarily participated in this study (19.1 ± 2.75 years). The dominant and non-dominant total glenohumeral rotational range of motion (TRROM), external rotation (ER), and internal rotation (IR) at 90° and 45° under active and passive conditions were evaluated. The GIRD and GERD were calculated in both positions and under both conditions. (3) Results: There were significant differences in all of the passive measurements between the 45° and 90° testing positions. The ER and TRROM at 90° and 45° showed significant differences under both passive and active conditions and on the dominant and non-dominant sides. Actively, there were no significant differences in the IR or TRROM for either the dominant or non-dominant side at 90° or 45°. (4) Conclusions: It is necessary to evaluate ER under the same conditions at 90° or 45°. Practitioners should consider assessing the ER for the angle at which most actions are repeated in tennis (45°) as a method to monitor GERDs. Evaluating GERDs in asymptomatic tennis players could help avoid future biomechanical and GIRD problems. Both GIRDs and GERDs should be considered as a percentage of the athlete’s own deficit in IR or ER, instead of referencing specific degrees that have been observed in baseball pitchers. Full article

Shoulder and elbow injuries are prevalent among baseball players, particularly pitchers, who experience repetitive eccentric loading of the shoulder, leading to muscle damage and increased injury risk. Nearly 40% of shoulder injuries in baseball occur in pitchers, with many facing low rates of return to sport. The rotator cuff (RC) muscles—supraspinatus (SSP), infraspinatus (ISP), subscapularis (SSC), and teres minor (TMin)—are crucial for shoulder stability, movement, and force generation, particularly in overhead sports. Each RC muscle comprises subregions with distinct biomechanical properties, such as strength, moment arm behavior, and activation patterns. These differences allow for a finely tuned balance between joint stability and mobility. For example, the superior subregion of the ISP significantly contributes to external rotation, a function critical in sports like baseball that require precision and power. During pitching, the SSP, ISP, and SSC stabilize the glenohumeral joint through high activation during explosive phases, such as stride, arm cocking, and arm acceleration. Understanding these functional subregional differences is vital for diagnosing and managing shoulder pathologies like RC tears. Despite advancements, clinicians face challenges in predicting re-injury risks and determining return-to-play readiness for athletes with shoulder injuries. Integrating insights into subregional biomechanics with patient care could enhance outcomes. Tailored interventions—whether surgical or rehabilitative—targeting specific subregions could improve recovery times, reduce re-injury risks, and enable more personalized treatment plans. Such approaches are especially beneficial for athletes, older individuals, and those prone to RC injuries, promoting better long-term shoulder health and performance. The present work aims to highlight some of the research on these subregions and their differences, providing insights to enhance treatment approaches for shoulder injuries. Full article

This study aimed to examine prospectively the relationship between the deep squatting test and medial elbow injuries in elementary school baseball players and to determine the usefulness of the lower extremity field test in throwing injuries. The participants were 254 players who had participated in preseason medical checkups in both 2019 and 2020 and had no problems with the 2019 medical checkups. The evaluation parameters included ultrasonography examination, physical examination, and three types of deep squatting tests. The success rate of deep squatting tests was significantly lower in the injured group than in the non-injured group in the medial elbow injuries. By the difficulty level, the backward test in the deep squatting test was more likely to predict medial elbow injuries than the forward and middle tests. Furthermore, there was a significant difference in the squatting test and medial elbow injuries by grades. In conclusion, this is the first prospective study to provide evidence that the deep squatting tests, classified by difficulty level, can predict the risk of subsequent medial elbow injuries in elementary school players. The deep squatting test may be useful as a field test for lower extremity flexibility that can be performed by athletes and instructors, as it can predict the risk of subsequent medial elbow injuries. Full article

The importance of dietary calcium intake in bone metabolism has been well established; however, it is still less investigated in health-related components, especially addressing muscle performance. This study aims to compare dietary calcium intake and its relationship with cardiovascular and muscular performance in young athletes (Lacrosse, Baseball, and soccer players). In this cross-sectional study, 95 participants (ages 18 to 30) participated during two visits to the Human Performance Laboratory. Participants completed body composition, lower and upper body muscle performance, cardiorespiratory protocol, and questionnaires related to dietary calcium intake. One-way ANOVA was used to determine the difference in the calcium intake between groups. The Pearson Correlation Coefficient was used to investigate the relationship between dietary calcium intake and muscle performance variables. Further, linear regression was used to assess the predictive value of calcium variables on overall muscle performance. Lacrosse players had significantly higher calcium intake than Baseball and soccer players (p < 0.05). There was a significant positive correlation between dietary calcium intake and the number of push-ups (r = 0.28; p = 0.03). CIBW and CI explained 4.3% and nearly 25% of the change in MPI, respectively (p < 0.001). This suggests the possible role of dietary calcium intake in enhancing health-related fitness components and highlights the need to explore its involvement in muscle-bone crosstalk. Full article

The hemostatic system is characterized by a delicate balance between pro- and anticoagulant forces, and the smallest alteration can cause serious events such as hemorrhages or thrombosis. Although exercise has been shown to play a protective role in athletes, several factors may increase the risk of developing venous thromboembolism (VTE), including hemoconcentration induced by exertion, immobilization following sports injuries, frequent long-distance flights, dehydration, and the use of oral contraceptives in female athletes. Biomarkers such as D-dimer, Factor VIII, thrombin generation, inflammatory cytokines, and leukocyte count are involved in the diagnosis of deep vein thrombosis (DVT), although their interpretation is complex and may indicate the presence of other conditions such as infections, inflammation, and heart disease. Therefore, the identification of biomarkers with high sensitivity and specificity is needed for the screening and early diagnosis of thromboembolism. Recent evidence about the correlation between the intensity of physical activity and VTE is divergent, whereas the repeated gestures in sports such as baseball, hockey, volleyball, swimming, wrestling, or, on the other hand, soccer players, runners, and martial art training represent a risk factor predisposing to the onset of upper and lower DVT. Anticoagulant therapy is the gold standard, reducing the risk of serious complications such as pulmonary embolism. The aim of this review is to provide a general overview about the interplay between physical exercise and the risk of thromboembolism in athletes, focusing on the main causes of thrombosis in professional athletes and underlying the need to identify new markers and therapies that can represent a valid tool for safeguarding the athlete’s health. Full article

Background and Objectives: Vision significantly contributes to postural control, balance, coordination, and body kinematics, thus deeply influencing everyday functionality. Sight-impaired subjects often show upper body anatomofunctional and kinetic chain alterations negatively impacting daily living efficiency and autonomy. The present study aimed to investigate and train, for the first time, upper body sensorimotor control in an Italian blind baseball team to boost global and segmental functionality while contemporarily prevent injuries. Materials and Methods: The whole team underwent a validated test battery using both quantitative traditional tools, such as goniometric active range of motion and muscular/functional tests, and an innovative biofeedback-based device, a Libra proprioceptive board. Consequently, a 6-week adapted training protocol was designed and leaded to improve sensorimotor control and, hence, counteract disability-related deficits and sport-specific overuse syndromes. Results: Statistically significant improvements were observed in all the investigated parameters. Noteworthy, an overall boost of global and segmental stability was detected through an orthostatic dynamic balance enhancement during the Y Balance test (p = 0.01) and trunk multiplanar control improvement on the Libra board (p = 0.01). Concurrently, the comparison of baseline vs. post-intervention outcomes revealed a consistent increase in upper body mobility (p < 0.05 for all the assessed districts), core recruitment (p = 0.01 for all the administered functional tests), and proprioceptive postural control (p = 0.01 for the Libra board validated test). Conclusions: Our findings suggest that a tailored sensorimotor training, conceived and led by an adapted physical activity kinesiologist, may effectively improve upper body functional prerequisites and global proprioceptive control, thus potentially promoting autonomy, quality of life, and physical activity/sport practice adherence in visually impaired individuals. Full article